Packing sheet, structured packing, gas-liquid contactor and direct air trapping system

Abstract

The utility model provides a packing sheet, structured packing, a gas-liquid contactor and a direct air trapping system. The packing sheet includes a leading edge and a trailing edge spaced apart by an air travel depth. In the mounted configuration, the leading edge is substantially parallel to the vertical direction. The upper and lower edges of the filler sheet are spaced apart by a liquid travel dimension parallel to a direction in which the CO2 capture solution travels from the upper edge to the lower edge. The mass transfer zone of the packing sheet includes a mass transfer microstructure having a microstructure height and configured to receive the CO2 capture solution and contact atmospheric air with the CO2 capture solution. The reinforcing elements of the filler sheet extend outwardly and have an orientation parallel to the liquid travel dimension. The spacers of the packing sheets are disposed on the mass transfer zone and spaced apart along a liquid travel dimension.

Description

TECHNICAL FIELD

[0001] The present disclosure describes systems, devices, and methods for capturing carbon dioxide. BACKGROUND

[0002] Capturing carbon dioxide (CO2) from the atmosphere is one approach to reducing greenhouse gas emissions and mitigating climate change. However, many technologies designed to capture CO2 from point emission sources, such as flue gas from industrial facilities, are generally ineffective at capturing CO2 from the atmosphere due to the significantly lower concentration of CO2 and the large volume of atmospheric air required for processing. In recent years, progress has been made in finding technologies more suitable for direct capture of CO2 from the atmosphere. Some of these direct air capture (DAC) systems use solid sorbents with active agents attached to a substrate. These DAC systems typically employ a cyclic sorption-desorption process in which, after the solid sorbent is saturated with CO2, it releases CO2 and is regenerated using humidity or thermal swing (thermal swing adsorption).

[0003] Other DAC systems use liquid sorbents (sometimes referred to as solvents) to capture CO2 from the atmosphere. One example of such a DAC system uses a fan to draw air through high surface area packing wetted with a solution containing a liquid sorbent. CO2 in the air reacts with the liquid sorbent to produce a CO2 rich solution. The rich solution is processed to regenerate a lean solution and release a concentrated carbon stream, such as CO, CO2, or other carbon products. SUMMARY

[0004] In an example embodiment, a packing sheet for transferring carbon dioxide (CO2) from atmospheric air to a CO2 capture solution includes a first side, a second side opposite the first side, a leading edge substantially parallel to a vertical direction in a mounted configuration of the packing sheet, a trailing edge spaced apart from the leading edge by an air travel depth parallel to a direction of travel of the atmospheric air from the leading edge to the trailing edge, a plurality of interconnected edges, a mass transfer zone, a plurality of stiffening elements extending outwardly from the first and second sides, and a plurality of spacers disposed on the mass transfer zone and extending outwardly from the first and second sides. The plurality of interconnected edges includes an upper edge extending between the leading edge and the trailing edge, and a lower edge extending between the leading edge and the trailing edge, the upper and lower edges spaced apart by a liquid travel dimension parallel to a direction of travel of the CO2 capture solution from the upper edge to the lower edge. The mass transfer zone is disposed on the first and second sides between the leading edge, the trailing edge, the upper edge, and the lower edge, and the mass transfer zone includes a plurality of mass transfer microstructures configured to receive the CO2 capture solution and contact the atmospheric air with the CO2 capture solution, the plurality of mass transfer microstructures having a microstructure height. Each of the plurality of stiffening elements has an orientation parallel to the liquid travel dimension. The plurality of spacers are spaced apart along the liquid travel dimension and have a spacer height greater than the microstructure height.

[0005] In aspects combinable with the foregoing, the packing sheet further includes a spacer alignment axis extending between at least two of the plurality of spacers aligned along the liquid travel dimension on the first and second sides between the upper and lower edges, the spacer alignment axis substantially parallel to the vertical direction in the mounted configuration of the packing sheet.

[0006] In aspects combinable with the foregoing, the packing sheet further includes a spacer alignment axis extending between at least two of the plurality of spacers aligned along the liquid travel dimension on the first and second sides between the upper and lower edges, the spacer alignment axis substantially parallel to the vertical direction in the mounted configuration of the packing sheet.

[0007] In aspects combinable with the foregoing, the plurality of stiffening elements includes a plurality of intermediate stiffening elements between the leading edge and the trailing edge, the plurality of intermediate stiffening elements including a plurality of intermediate stiffeners positioned adjacent to each other along the liquid travel dimension, each of the plurality of intermediate stiffeners extending outwardly from one of the first and second sides to an attachment wall, the attachment wall defining a stiffener height greater than the microstructure height.

[0008] In another aspect combinable with any of the preceding aspects, the plurality of intermediate reinforcements includes a first set of intermediate reinforcements extending outward from the first side and a second set of intermediate reinforcements extending outward from the second side, the first set of intermediate reinforcements forming a first set of recesses on the second side and the second set of intermediate reinforcements forming a second set of recesses on the first side. The first set of intermediate reinforcements alternate along the axis with the second set of recesses on the first side and the second set of intermediate reinforcements alternate along the axis with the first set of recesses on the second side.

[0009] In another aspect combinable with any of the preceding aspects, each of the plurality of intermediate reinforcements includes a plurality of planar walls extending outward from one of the first side and the second side to the attachment wall; and a plurality of flow channels, each of the plurality of flow channels disposed in one of the plurality of planar walls.

[0010] In another aspect combinable with any of the preceding aspects, the plurality of flow channels includes at least one longitudinal flow channel parallel to the liquid travel dimension; and at least one lateral flow channel including an inlet end and an outlet end, the inlet end closer to the attachment wall than the outlet end.

[0011] In another aspect combinable with any of the preceding aspects, the plurality of reinforcing elements includes a plurality of perimeter ribs adjacent to at least one of the trailing edge and the leading edge, each of the plurality of perimeter ribs extending outward from one of the first side and the second side and forming a respective recess in the other of the first side and the second side.

[0012] In another aspect combinable with any of the preceding aspects, the plurality of perimeter ribs includes a plurality of leading edge ribs adjacent to the leading edge, the plurality of leading edge ribs including a set of innermost ribs extending outward from the first side and forming respective recesses in the second side; and a set of outermost ribs extending outward from the second side and forming respective recesses in the first side, the set of outermost ribs spaced further from the leading edge along the air travel depth than the set of innermost ribs.

[0013] In another aspect combinable with any of the preceding aspects, the plurality of perimeter ribs includes a plurality of trailing edge ribs adjacent to the trailing edge, the plurality of trailing edge ribs including a third set of ribs extending outward from the first side and forming respective recesses in the second side; and a fourth set of ribs extending outward from the second side and forming respective recesses in the first side, the fourth set of ribs spaced further from the trailing edge along the air travel depth than the third set of ribs.

[0014] In another aspect combinable with any of the previous aspects, the plurality of perimeter ribs includes at least one pair of longitudinal ribs having two perimeter ribs spaced apart from one another in a direction parallel to the liquid travel dimension to define a longitudinal pair gap, wherein some of the plurality of mass transfer microstructures are present in the longitudinal pair gap.

[0015] In another aspect combinable with any of the previous aspects, the plurality of perimeter ribs includes at least one pair of lateral ribs having two perimeter ribs spaced apart from one another in a direction parallel to the air travel depth to define a lateral pair gap, and some of the plurality of mass transfer microstructures are present in the lateral pair gap.

[0016] In another aspect combinable with any of the previous aspects, the plurality of reinforcing elements includes a plurality of perimeter reinforcements positioned adjacent to one another along the liquid travel dimension, the plurality of perimeter reinforcements defining at least one of a trailing edge and a leading edge.

[0017] In another aspect combinable with any of the previous aspects, the plurality of spacing portions includes a plurality of pairs of spacing portions spaced apart along the liquid travel dimension and along the air travel depth, the spacing portions in each of the plurality of pairs of spacing portions being spaced apart in a direction parallel to the air travel depth.

[0018] In another aspect combinable with any of the previous aspects, the spacing portions in each of the pairs of spacing portions include a first spacing portion extending outwardly from a first side and forming a respective recess in a second side, and a second spacing portion extending outwardly from the second side and forming a respective recess in the first side.

[0019] In another aspect combinable with any of the previous aspects, the plurality of reinforcing elements includes a plurality of intermediate reinforcing elements positioned between the leading edge and the trailing edge, at least the plurality of intermediate reinforcing elements including a plurality of intermediate ribs having an orientation parallel to the liquid travel dimension, the plurality of intermediate ribs including a first set of ribs spaced apart along the liquid travel dimension and extending outwardly from a first side and forming respective recesses in a second side, and a second set of ribs spaced apart along the liquid travel dimension and extending outwardly from the second side and forming respective recesses in the first side, the second set of ribs being spaced apart from the first set of ribs in a direction parallel to the air travel depth.

[0020] In another aspect combinable with any of the previous aspects, each rib in the first set of ribs includes a first rib end and a second rib end; and each rib in the second set of ribs includes a third rib end and a fourth rib end, the third rib end of at least one rib in the second set of ribs being positioned between the first rib end and the second rib end of at least one rib in the first set of ribs.

[0021] In another aspect combinable with any of the previous aspects, the filler sheet has a rectangular shape, the leading edge and the trailing edge are substantially parallel to a vertical line in the installed configuration of the filler sheet, the upper edge is perpendicular to the leading edge and the trailing edge, and the lower edge is perpendicular to the leading edge and the trailing edge.

[0022] In another aspect combinable with any of the previous aspects, the liquid travel dimension is greater than the air travel depth.

[0023] In another aspect combinable with any of the previous aspects, the air travel depth is 3 feet to 5 feet.

[0024] In another aspect combinable with any of the previous aspects, at least some of the plurality of mass transfer microstructures include a first wall portion extending toward a first apex on the first side; and a second wall portion extending from the first apex to a second apex on the second side, at least one of the first wall portion and the second wall portion including at least one wall feature extending from the at least one of the first wall portion and the second wall portion.

[0025] In another aspect combinable with any of the previous aspects, the at least one wall feature includes a first wall feature extending outwardly from the first wall portion on the first side; and a second wall feature extending outwardly from the second wall portion on the second side.

[0026] In another aspect combinable with any of the previous aspects, the filler sheet further includes a center of mass, the filler sheet having point symmetry about the center of mass.

[0027] In another aspect combinable with any of the previous aspects, the plurality of reinforcing elements includes a plurality of reinforcing bodies positioned adjacent to each other along the air travel depth and between the leading edge and the trailing edge.

[0028] In another aspect combinable with any of the previous aspects, the plurality of reinforcing bodies is disposed between the upper edge and the lower edge.

[0029] In another aspect combinable with any of the previous aspects, the plurality of reinforcing bodies defines at least one of the upper edge and the lower edge.

[0030] In another aspect combinable with any of the previous aspects, each of the plurality of reinforcing bodies extends outwardly from at least one of the first side or the second side to an attachment wall, the attachment wall defining a body height that is greater than the microstructure height.

[0031] In another aspect combinable with any of the preceding aspects, the plurality of reinforcements includes a first set of reinforcements extending outward from the first side and a second set of reinforcements extending outward from the second side. The first set of reinforcements forms a first set of depressions on the second side, and the second set of reinforcements forms a second set of depressions on the first side. The first set of reinforcements alternate along the horizontal axis with the second set of depressions on the first side, and the second set of reinforcements alternate along the horizontal axis with the first set of depressions on the second side.

[0032] In another aspect combinable with any of the preceding aspects, each reinforcement of the plurality of reinforcements includes a plurality of planar walls extending outward from at least one of the first side or the second side to the attachment wall, and at least one flow channel extending on at least one of the first side or the second side into one of the plurality of planar walls, the at least one flow channel being parallel to the air travel depth.

[0033] In another aspect combinable with any of the preceding aspects, each reinforcement of the plurality of reinforcements includes a plurality of planar walls extending outward from at least one of the first side or the second side to the attachment wall, the attachment wall having an attachment wall slope, at least one of the plurality of planar walls including a stepped member. The stepped member includes a first wall segment extending from the attachment wall and having a first slope different from the attachment wall slope, a second wall segment extending from the first wall segment and having a second slope different from the first slope, and a third wall segment extending from the second wall segment and having a third slope different from the second slope.

[0034] In another aspect combinable with any of the preceding aspects, at least some of the plurality of mass transfer microstructures include a plurality of base microstructures including first and second wall portions extending toward a first apex on one of the first and second sides, and a plurality of supplemental microstructures projecting outward from the first and second wall portions of the plurality of base microstructures.

[0035] In another example embodiment, a structured packing for transferring carbon dioxide (CO2) from atmospheric air to a CO2 capture solution includes a plurality of packing sheets attached together. At least one packing sheet of the plurality of packing sheets includes a first side; a second side opposite the first side; a leading edge; a trailing edge spaced apart from the leading edge by an air travel depth parallel to a direction of travel of the atmospheric air from the leading edge to the trailing edge, a plurality of interconnected edges, a mass transfer zone, a plurality of stiffening elements extending outwardly from the first and second sides, and a plurality of spacers disposed on the mass transfer zone and extending outwardly from the first and second sides. In an installed configuration of the at least one packing sheet, the leading edge of the at least one packing sheet is substantially parallel to a vertical direction. The plurality of interconnected edges includes an upper edge extending between the leading edge and the trailing edge, and a lower edge extending between the leading edge and the trailing edge, the upper edge and the lower edge spaced apart by a liquid travel dimension parallel to a direction of travel of the CO2 capture solution from the upper edge to the lower edge. The mass transfer zone is disposed on the first and second sides between the leading edge, the trailing edge, the upper edge, and the lower edge, the mass transfer zone including a plurality of mass transfer microstructures having a microstructure height and configured to contact the CO2 capture solution with the atmospheric air. Each of the plurality of stiffening elements has an orientation parallel to the liquid travel dimension. The plurality of spacers are spaced apart along the liquid travel dimension and have a spacer height greater than the microstructure height. Adjacent packing sheets of the plurality of packing sheets are attached along the respective plurality of spacers and define an airflow passage through which the atmospheric air travels from the leading edge to the trailing edge.

[0036] In aspects combinable with any of the foregoing aspects, the airflow passage has a rectangular passage shape defined in a plane perpendicular to the liquid travel dimension.

[0037] In another aspect combinable with any of the foregoing aspects, the plurality of stiffening elements includes a plurality of intermediate stiffening elements between the leading edge and the trailing edge, the plurality of intermediate stiffening elements including a plurality of intermediate stiffeners positioned adjacent to each other along the liquid travel dimension, each of the plurality of intermediate stiffeners extending outwardly from one of the first and second sides to an attachment wall defining a stiffener height greater than the microstructure height. Adjacent packing sheets are attached along their attachment walls.

[0038] In another aspect combinable with any of the preceding aspects, each of the plurality of intermediate stiffeners includes a plurality of planar walls extending outward from one of the first side and the second side to the attachment wall, and a plurality of flow channels, each of the plurality of flow channels disposed in a planar wall of the plurality of planar walls, the plurality of flow channels including at least one longitudinal flow channel parallel to the liquid travel dimension and extending from the attached attachment wall of the adjacent filler sheet.

[0039] In another aspect combinable with any of the preceding aspects, the plurality of intermediate stiffeners includes a first set of stiffeners extending outward from the first side and a second set of stiffeners extending outward from the second side, the first set of stiffeners forming a first set of recesses on the second side and the second set of stiffeners forming a second set of recesses on the first side, the first set of stiffeners alternating with the second set of recesses on the first side along an axis, and the second set of stiffeners alternating with the first set of recesses on the second side along the axis, the gas flow channel between the adjacent filler sheets extending through the first set of recesses and the second set of recesses.

[0040] In another aspect combinable with any of the preceding aspects, the plurality of stiffening elements includes a plurality of intermediate stiffening elements between a leading edge and a trailing edge, at least a plurality of the intermediate stiffening elements including a plurality of intermediate ribs having an orientation parallel to the liquid travel dimension; the plurality of stiffening elements including a plurality of perimeter stiffening elements disposed proximate at least one of the trailing edge and the leading edge, the plurality of perimeter stiffening elements including a plurality of perimeter stiffeners positioned adjacent to each other along the liquid travel dimension, the plurality of perimeter stiffeners defining at least one of the trailing edge and the leading edge; and an intermediate rib height of the plurality of intermediate ribs is less than a perimeter stiffener height of the plurality of perimeter stiffeners.

[0041] In another aspect combinable with any of the preceding aspects, the plurality of stiffening elements includes a plurality of perimeter stiffeners positioned adjacent to each other along the liquid travel dimension, the plurality of perimeter stiffeners defining at least one of the trailing edge and the leading edge, the plurality of perimeter stiffeners including a first set of stiffeners extending outward from the first side and a second set of stiffeners extending outward from the second side. The first set of stiffeners forms a first set of recesses on the second side and the second set of stiffeners forms a second set of recesses on the first side, the first set of stiffeners alternating along an axis with the second set of recesses on the first side and the second set of stiffeners alternating along the axis with the first set of recesses on the second side, the first set of stiffeners of a first one of the adjacent filler sheets attached to the second set of stiffeners of a second one of the adjacent filler sheets forming a stiffener flow passage between the first and second sets of recesses of the adjacent filler sheets, the stiffener flow passage in fluid communication with the gas flow passage.

[0042] In another aspect combinable with any of the preceding aspects, the structured packing further includes a spacer alignment axis extending on the first side and the second side between the upper edge and the lower edge, the spacer alignment axis extending between at least two spacers of the plurality of spacers aligned along the liquid travel dimension, the spacer alignment axis substantially parallel to a vertical direction in the installed configuration of the at least one filler sheet.

[0043] In another aspect combinable with any of the preceding aspects, the structured packing further includes a spacer alignment axis extending on the first side and the second side between the upper edge and the lower edge, the spacer alignment axis extending between at least two spacers of the plurality of spacers aligned along the liquid travel dimension, the spacer alignment axis substantially parallel to a vertical direction in the installed configuration of the at least one filler sheet.

[0044] In another aspect combinable with any of the preceding aspects, the plurality of stiffening elements includes a plurality of intermediate stiffeners between the leading edge and the trailing edge, at least a plurality of the intermediate stiffeners including a plurality of intermediate stiffeners positioned adjacent to each other along the liquid travel dimension, each of the plurality of intermediate stiffeners extending outward from one of the first side and the second side to an attachment wall, the attachment wall defining a stiffener height greater than the microstructure height.

[0045] In another aspect combinable with any of the preceding aspects, the plurality of intermediate reinforcements includes a first set of intermediate reinforcements extending outward from the first side and a second set of intermediate reinforcements extending outward from the second side, the first set of intermediate reinforcements forming a first set of recesses on the second side and the second set of intermediate reinforcements forming a second set of recesses on the first side. The first set of intermediate reinforcements alternate along the axis with the second set of recesses on the first side and the second set of intermediate reinforcements alternate along the axis with the first set of recesses on the second side.

[0046] In another aspect combinable with any of the preceding aspects, each of the plurality of intermediate reinforcements includes a plurality of planar walls extending outward from one of the first side and the second side to the attachment wall, and a plurality of flow channels, each of the plurality of flow channels disposed in one of the plurality of planar walls.

[0047] In another aspect combinable with any of the preceding aspects, the plurality of flow channels includes at least one longitudinal flow channel parallel to the liquid travel dimension, and at least one lateral flow channel including an inlet end and an outlet end, the inlet end closer to the attachment wall than the outlet end.

[0048] In another aspect combinable with any of the preceding aspects, the plurality of reinforcing elements includes a plurality of perimeter ribs adjacent to at least one of the trailing edge and the leading edge, each of the plurality of perimeter ribs extending outward from one of the first side and the second side and forming a corresponding recess in the other of the first side and the second side.

[0049] In another aspect combinable with any of the preceding aspects, the plurality of perimeter ribs includes a plurality of leading edge ribs adjacent to the leading edge, the plurality of leading edge ribs including a set of innermost ribs and a set of outermost ribs spaced further from the leading edge along the air travel depth than the set of innermost ribs, the set of innermost ribs extending outward from the first side and forming a corresponding recess in the second side, the set of outermost ribs extending outward from the second side and forming a corresponding recess in the first side.

[0050] In another aspect combinable with any of the preceding aspects, the plurality of perimeter ribs includes a plurality of trailing edge ribs adjacent to the trailing edge, the plurality of trailing edge ribs including a third set of ribs and a fourth set of ribs spaced further from the trailing edge along the air travel depth than the third set of ribs, the third set of ribs extending outward from the first side and forming a corresponding recess in the second side, the fourth set of ribs extending outward from the second side and forming a corresponding recess in the first side.

[0051] In another aspect combinable with any of the preceding aspects, the plurality of perimeter ribs includes at least one pair of longitudinal ribs having two perimeter ribs spaced apart from one another in a direction parallel to the liquid travel dimension to define a longitudinal pair gap, wherein some of the plurality of mass transfer microstructures are present in the longitudinal pair gap.

[0052] In another aspect combinable with any of the preceding aspects, the plurality of perimeter ribs includes at least one pair of lateral ribs having two perimeter ribs spaced apart from one another in a direction parallel to the air travel depth to define a lateral pair gap, and some of the plurality of mass transfer microstructures are present in the lateral pair gap.

[0053] In another aspect combinable with any of the preceding aspects, the plurality of reinforcing elements includes a plurality of perimeter reinforcing bodies positioned adjacent to one another along the liquid travel dimension, the plurality of perimeter reinforcing bodies defining at least one of the trailing edge and the leading edge.

[0054] In another aspect combinable with any of the preceding aspects, the plurality of spacing sections includes a plurality of pairs of spacing sections spaced apart along the liquid travel dimension and along the air travel depth, the spacing sections in each pair of spacing sections being spaced apart in a direction parallel to the air travel depth.

[0055] In another aspect combinable with any of the preceding aspects, the spacing sections in each pair of spacing sections include a first spacing section extending outwardly from the first side and forming a respective recess in the second side, and a second spacing section extending outwardly from the second side and forming a respective recess in the first side.

[0056] In another aspect combinable with any of the preceding aspects, the plurality of reinforcing elements includes a plurality of intermediate reinforcing elements between the leading edge and the trailing edge, at least the plurality of intermediate reinforcing elements including a plurality of intermediate ribs having an orientation parallel to the liquid travel dimension, the plurality of intermediate ribs including a first set of ribs spaced apart along the liquid travel dimension, the first set of ribs extending outwardly from the first side and forming respective recesses in the second side, and a second set of ribs spaced apart along the liquid travel dimension, the second set of ribs spaced apart from the first set of ribs in a direction parallel to the air travel depth, the first set of ribs extending outwardly from the first side and forming respective recesses in the second side, the second set of ribs extending outwardly from the second side and forming respective recesses in the first side.

[0057] In another aspect combinable with any of the previous aspects, each rib of the first set of ribs includes a first rib end and a second rib end; and each rib of the second set of ribs includes a third rib end and a fourth rib end, the third rib end of at least one rib of the second set of ribs is positioned between the first rib end and the second rib end of at least one rib of the first set of ribs.

[0058] In another aspect combinable with any of the previous aspects, the packing sheet has a rectangular shape, in the installed configuration of at least one packing sheet, the leading edge and the trailing edge are substantially parallel to the vertical line; the upper edge is perpendicular to the leading edge and the trailing edge; and the lower edge is perpendicular to the leading edge and the trailing edge.

[0059] In another aspect combinable with any of the previous aspects, the liquid travel dimension is greater than the air travel depth.

[0060] In another aspect combinable with any of the previous aspects, the air travel depth is 3 feet to 5 feet.

[0061] In another aspect combinable with any of the previous aspects, at least one mass transfer microstructure of the plurality of mass transfer microstructures includes a first wall portion extending toward a first apex on the first side, and a second wall portion extending from the first apex to a second apex on the second side, at least one of the first wall portion and the second wall portion includes at least one wall feature extending from at least one of the first wall portion and the second wall portion.

[0062] In another aspect combinable with any of the previous aspects, the at least one wall feature includes a first wall feature extending outward from the first wall portion on the first side, and a second wall feature extending outward from the second wall portion on the second side.

[0063] In another aspect combinable with any of the previous aspects, the structured packing further includes a centroid, the at least one packing sheet has point symmetry about the centroid.

[0064] In another example embodiment, a gas-liquid contactor for capturing carbon dioxide (CO2) from atmospheric air includes at least one inlet; at least one outlet spaced apart from the at least one inlet; at least one packing section disposed between the at least one inlet and the at least one outlet, the at least one packing section including at least one structured packing, one or more liquid collection devices including a bottom liquid collection device located at least partially below the at least one packing section, the one or more liquid collection devices configured to contain a CO2 capture solution; a fan operable to flow atmospheric air (1) from the at least one inlet to the at least one outlet and (2) along air travel depths parallel to a liquid travel dimension of air flow channels of the at least one structured packing; and a liquid distribution system fluidly connected to the at least one packing section. The at least one structured packing includes a plurality of packing sheets attached together. At least one packing sheet of the plurality of packing sheets includes: a first side; a second side opposite the first side; a leading edge substantially parallel to the vertical direction; a trailing edge spaced apart from the leading edge by an air travel depth; a plurality of interconnecting edges including an upper edge extending between the leading edge and the trailing edge and a lower edge extending between the leading edge and the trailing edge, the upper edge and the lower edge spaced apart by a liquid travel dimension; a mass transfer zone disposed on the first side and the second side between the leading edge, the trailing edge, the upper edge, and the lower edge, the mass transfer zone including a plurality of mass transfer microstructures having a microstructure height; a plurality of stiffening elements extending outwardly from the first side and the second side, each stiffening element of the plurality of stiffening elements having an orientation parallel to the liquid travel dimension; and a plurality of spacers disposed on the mass transfer zone and extending outwardly from the first side and the second side, the plurality of spacers spaced apart and having a spacer height greater than the microstructure height. Adjacent packing sheets of the plurality of packing sheets are attached along respective plurality of spacers and define air flow channels. The liquid distribution system is operable to flow the CO2 capture solution along the plurality of mass transfer microstructures in the liquid travel dimension to contact the atmospheric air with the CO2 capture solution and absorb CO2 from the atmospheric air into the CO2 capture solution.

[0065] In aspects that can be combined with example embodiments, the gas-liquid contactor further includes a housing defining an interior at least partially exposed to atmospheric air, the interior disposed between the at least one inlet and the at least one outlet, the at least one structured packing including a plurality of structured packings disposed within the interior and forming at least one structured packing arrangement, structured packings of the at least one structured packing arrangement positioned vertically and laterally adjacent to each other.

[0066] In another aspect combinable with any of the previous aspects, the at least one structured packing arrangement includes an upper structured packing arrangement; a lower structured packing arrangement vertically spaced below the upper structured packing arrangement, and a redistribution gap defined between the upper and lower structured packing arrangements; and the one or more liquid collection devices include a redistribution trough located in the redistribution gap between the upper and lower structured packing arrangements, the redistribution trough configured to collect CO2 capture solution from the upper structured packing arrangement and redistribute the CO2 capture solution over the lower structured packing arrangement.

[0067] In another aspect combinable with any of the previous aspects, the housing includes a plurality of interconnected structural members, the plurality of structured packings being mounted to at least one of: an interconnected structural member of the plurality of interconnected structural members, and another structured packing of the plurality of structured packings.

[0068] In another aspect combinable with any of the previous aspects, the liquid distribution system is operable to flow the CO2 capture solution at a liquid loading flow rate in a range of 0.5 L / m 2 s to 10 L / m 2 s.

[0069] In another aspect combinable with any of the previous aspects, the at least one packing section includes a first packing section; and a second packing section spaced from the first packing section by a plenum; the fan is operable to flow the atmospheric air into the first and second packing sections at an air velocity in a range of 0.1 m / s to 5 m / s, and along a horizontal flow direction through the first and second packing sections and into the plenum; and the liquid distribution system is operable to flow the CO2 capture solution at a liquid progression dimension that is predominantly vertically downward.

[0070] In another example embodiment, a packing sheet for transferring carbon dioxide (CO2) from atmospheric air to a CO2 capture solution includes a first side; a second side opposite the first side; a leading edge; a trailing edge spaced apart from the leading edge by an air travel depth, the air travel depth being parallel to a direction of travel of atmospheric air from the leading edge to the trailing edge, the leading edge being substantially parallel to a vertical direction in a mounted configuration of the packing sheet; a plurality of interconnected edges including an upper edge extending between the leading edge and the trailing edge and a lower edge extending between the leading edge and the trailing edge, the upper edge and the lower edge being spaced apart by a liquid travel dimension, the liquid travel dimension being parallel to a direction of travel of the CO2 capture solution from the upper edge to the lower edge; a mass transfer zone disposed on the first side and the second side between the leading edge, the trailing edge, the upper edge, and the lower edge, the mass transfer zone including a plurality of mass transfer microstructures having a microstructure height, the plurality of mass transfer microstructures being configured to receive the CO2 capture solution and contact the atmospheric air with the CO2 capture solution; at least one reinforcing element extending outwardly from one of the first side and the second side, the at least one reinforcing element having an orientation parallel to the liquid travel dimension, one or more mass transfer microstructures of the plurality of mass transfer microstructures being disposed on the at least one reinforcing element; and a plurality of spacers disposed on the mass transfer zone and extending outwardly from the first side and the second side, the plurality of spacers being spaced apart along the liquid travel dimension and having a spacer height that is greater than the microstructure height.

[0071] In another example embodiment, a method for capturing carbon dioxide (CO2) from atmospheric air includes flowing atmospheric air in a first flow direction from a leading edge of a plurality of packing sheets to a trailing edge of the plurality of packing sheets, the first flow direction being substantially perpendicular to the leading edge of the plurality of packing sheets; and flowing a CO2 capture solution over the plurality of packing sheets in a second flow direction to absorb CO2 from the atmospheric air into the CO2 capture solution, the second flow direction being substantially perpendicular to the first flow direction.

[0072] In another example embodiment, a direct air capture (DAC) system for capturing carbon dioxide (CO2) from atmospheric air includes at least one gas-liquid contactor, a liquid distribution system, a regeneration system in fluid communication with the liquid distribution system. The at least one gas-liquid contactor includes at least one inlet, at least one outlet spaced apart from the at least one inlet, at least one packing section disposed between the at least one inlet and the at least one outlet, and a fan. The at least one packing section includes at least one structured packing. The at least one structured packing includes a plurality of packing sheets attached together. At least one packing sheet of the plurality of packing sheets includes a first side, a second side opposite the first side, a leading edge substantially parallel to the vertical direction, a trailing edge spaced apart from the leading edge by an air travel depth, a plurality of interconnecting edges including an upper edge extending between the leading edge and the trailing edge and a lower edge extending between the leading edge and the trailing edge, the upper edge and the lower edge spaced apart by a liquid travel dimension, a mass transfer zone disposed on the first side and the second side between the leading edge, the trailing edge, the upper edge, and the lower edge, the mass transfer zone including a plurality of mass transfer microstructures having a microstructure height, a plurality of stiffening elements extending outwardly from the first side and the second side, each stiffening element of the plurality of stiffening elements having an orientation parallel to the liquid travel dimension, and a plurality of spacers disposed on the mass transfer zone and extending outwardly from the first side and the second side, the plurality of spacers spaced apart and having a spacer height greater than the microstructure height, adjacent packing sheets of the plurality of packing sheets attached along respective plurality of spacers and defining an air flow channel. The fan is operable to flow atmospheric air (1) from the at least one inlet to the at least one outlet and (2) parallel to the air travel depth along the air flow channel of the at least one structured packing. The liquid distribution system is fluidly connected to the at least one packing section and is operable to flow a CO2 capture solution through the mass transfer microstructures of the at least one packing section, the CO2 capture solution configured to absorb CO2 from the atmospheric air. The liquid distribution system includes one or more liquid collection devices including a bottom liquid collection device positioned at least partially below the at least one packing section, the one or more liquid collection devices configured to hold the CO2 capture solution. The regeneration system receives the CO2 capture solution and is configured to regenerate the CO2 capture solution and form a CO2-lean liquid for return to the at least one gas-liquid contactor.

[0073] In aspects combinable with example embodiments, the regeneration system is configured to provide a CO2 product stream for output or use.

[0074] Embodiments of systems and methods for capturing carbon dioxide according to the present disclosure can include one, some or all of the following features. For example, the packing with the features described herein is specifically designed for commercial DAC applications and, as such, has the ability to reduce at least one of air volume, packing depth, liquid flow, and air contactor footprint without significantly sacrificing CO2absorption performance. Design criteria for DAC packing that reflect good performance include: low static pressure design, ability to distribute liquid evenly across the packing height, low fouling ability, improvement in air contact efficiency, lower material requirements, efficiency effects of larger packing size, and manufacturability.

[0075] The details of one or more implementations of the subject matter described in this disclosure are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages of the subject matter will become apparent from the description, the drawings, and the claims. BRIEF DESCRIPTION OF DRAWINGS

[0076] Figure 1 An example gas-liquid contactor is shown.

[0077] Figure 2A Another example gas-liquid contactor is shown.

[0078] Figure 2B Another example gas-liquid contactor is shown.

[0079] Figure 3 An example packing sheet for a gas-liquid contactor of the present disclosure is shown.

[0080] Figure 4 is an enlarged view of the IV-IV portion of the packing sheet of Figure 3

[0081] Figure 4A is a cross-sectional view taken along line 4A-4A in Figure 4

[0082] Figure 4B is a cross-sectional view taken along line 4B-4B in Figure 4

[0083] Figure 4C is a cross-sectional view taken along line 4C-4C in Figure 4

[0084] Figure 4D is a cross-sectional view taken along line 4D-4D in Figure 4

[0085] Figure 4E is a cross-sectional view taken along line 4E-4E in Figure 4

[0086] ​​​​​​Figure 5 yes Figure 4 A magnified view of part of VV.

[0087] Figure 5A This is an enlarged view of a portion of an exemplary packing sheet used in the gas-liquid contactor of this disclosure.

[0088] Figure 6 An exemplary packing sheet for a gas-liquid contactor used in this disclosure is shown.

[0089] Figure 7 An exemplary packing sheet for a gas-liquid contactor used in this disclosure is shown.

[0090] Figure 7A It is along Figure 7 The cross-sectional view taken from line 7A-7A in the diagram.

[0091] Figure 8 An exemplary packing sheet for a gas-liquid contactor used in this disclosure is shown.

[0092] Figure 8A yes Figure 8 A magnified view of part VIIIA.

[0093] Figure 8A1 It is along Figure 8A The cross-sectional view taken from line 8A1-8A1 in the diagram.

[0094] Figure 8A2 It is along Figure 8A The cross-sectional view taken from line 8A2-8A2 in the diagram.

[0095] Figure 8B yes Figure 8 A magnified view of part VIIIB.

[0096] Figure 8B1 It is along Figure 8B The cross-sectional view taken from line 8B1-8B1 in the diagram.

[0097] Figure 8B2 It is along Figure 8B The cross-sectional view taken from line 8B2-8B2 in the diagram.

[0098] Figure 8C yes Figure 8 An enlarged perspective view of a portion of an exemplary packing sheet.

[0099] Figure 9 This is a perspective view of a portion of an exemplary packing sheet used in the gas-liquid contactor of this disclosure.

[0100] Figure 10 An exemplary structured packing formed from the packing sheets of this disclosure is shown.

[0101] Figure 11 is a front view of a structured packing of Figure 10

[0102] Figure 12 is a top view of a structured packing of Figure 10

[0103] Figure 13 shows an exemplary mass transfer microstructure of a packing sheet of the present disclosure.

[0104] Figure 14 shows an exemplary mass transfer microstructure of a packing sheet of the present disclosure.

[0105] Figure 15 is a schematic diagram of a direct air capture system having a gas-liquid contactor of the present disclosure.

[0106] Figure 16 is a schematic flow diagram of a method for capturing carbon dioxide (CO2) from the atmosphere.

[0107] Figure 17 is a schematic diagram of a control system (or controller) for a gas-liquid contactor of the present disclosure.

[0108] Figure 18A shows an exemplary mass transfer microstructure of a packing sheet of the present disclosure.

[0109] Figure 18B is a magnified view of portion 18B-18B of Figure 18A

[0110] Figure 19 is a schematic diagram of another direct air capture system having a gas-liquid contactor of the present disclosure.

[0111] Figure 20 is a schematic diagram of another direct air capture system having a gas-liquid contactor of the present disclosure. DETAILED DESCRIPTION

[0112] Reference is made to Figure 1 ​​​The present disclosure describes systems and methods for capturing carbon dioxide (CO2) from the atmosphere (e.g., ambient air or atmospheric air) or from another fluid source containing dilute concentrations of CO2 using a gas-liquid contactor 100. The concentration of CO2 in the atmosphere is dilute in that they are currently in the range of 400-420 parts per million (“ppm”) or about 0.04-0.042% v / v, and less than 1% v / v. These atmospheric concentrations of CO2 are at least an order of magnitude lower than the concentration of CO2 in point source emissions (such as flue gas), which can have a CO2 concentration in the range of 5-15% v / v, depending on the source of the emissions. In some embodiments, the gas-liquid contactor 100 is operated to capture dilute CO2 present in ambient air by drawing the ambient air as a fluid containing CO2 air 101, and by treating the CO2 containing air 101 so as to transfer the CO2 present therein to a CO2 capture solution 114 (e.g., a CO2 sorbent) via absorption. Some or all of the CO2 in the CO2 containing air 101 is removed, and the treated CO2 containing air 101 is then discharged as a fluid of CO2 lean gas 105 (or low CO2 air) by the gas-liquid contactor 100. In operation treating atmospheric air in this manner, the gas-liquid contactor 100 can sometimes be referred to herein as an “air contactor” in that it facilitates the absorption of CO2 from atmospheric air into the CO2 capture solution 114. In contrast to a water cooling tower, which is primarily used to transfer heat between water and the atmosphere, the gas-liquid contactor 100 is primarily used to effect mass transfer of CO2 from the atmosphere to the CO2 capture solution 114. When operated in this manner, the gas-liquid contactor 100 can be used as part of a direct air capture (DAC) system 1200, described below with reference to FIG. 12. Figure 15 More detail is described.

[0113] In some embodiments, and with reference to Figure 1The CO2 capturing solution 114 is a caustic alkaline solution. In some embodiments, the CO2 capturing solution 114 has a pH of 10 or higher. In some embodiments, the CO2 capturing solution 114 has a pH of approximately 14. Non-limiting examples of the CO2 capturing solution 114 include aqueous alkaline solutions (e.g., KOH, NaOH, or combinations thereof), aqueous amines, aqueous amino acid salt solutions, non-aqueous solutions of amines, non-aqueous organic liquids / solutions (e.g., dimethyl sulfoxide or DMSO), aqueous carbonate and / or bicarbonate solutions, benzene oxides / phenolic salts, ionic liquids, non-aqueous solvents, diamines having an aminocyclohexyl group (e.g., IPDA), or combinations thereof. In some cases, the CO2 capturing solution 114 may include promoters and / or additives that increase CO2 absorption. Non-limiting examples of promoters include carbonic anhydrase, amines (primary, secondary, tertiary amines), and boric acid. Non-limiting examples of additives include chlorides, sulfates, acetates, phosphates, surfactants, oxides, and metal oxides. For example, surfactants can be added to CO2 trapping solution 114 to reduce its surface tension, thereby improving its ability to wet the filler. Non-limiting examples of rate-enhancing additives include carbonic anhydrase, piperazine, monoethanolamine (MEA), diethanolamine (DEA), zinc triazacycles, zinc tetraazacycles, copper glycinate, hydroxopentaaminecobaltperchlorate, formaldehyde hydrate, sucrose, fructose, glucose, phenols, phenolates, glycerol, arsenite, hypochlorite, hypobromite, or other oxyanionic substances.

[0114] In some embodiments, at a given reference temperature, the density of the CO2 trapping solution 114 is greater than the density of water at the same reference temperature. In some embodiments, at a comparable reference temperature, the density of the CO2 trapping solution 114 is at least 10% greater than the density of water. In some embodiments, at a comparable reference temperature, the density of the CO2 trapping solution 114 is approximately 10% greater than the density of water. The density and viscosity of the CO2 trapping solution 114 can vary depending on its composition and temperature. For example, at temperatures from 0°C to 20°C, the CO2 trapping solution 114 or the CO2-containing trapping solution 111 may contain 1 M KOH and 0.5 M K2CO3, and may have a viscosity in the range of 1115 kg / m³. 3 -1119kg / m 3and a viscosity ranging from 1.3 mPa-s to 2.3 mPa-s. In another example, at a temperature of 20 °C to 0 °C, the CO2capture solution 114 or the CO2-containing capture solution 111 can comprise 2 M KOH and 1 M K2CO3, and can have a density ranging from 1260 kg / m 3 -1266 kg / m 3 and a viscosity ranging from 1.8 mPa-s to 3.1 mPa-s. In comparison, water has a density of 998 kg / m 3 at 20 °C and a viscosity of 1 mPa-s.

[0115] In some embodiments, and with reference to Figure 1 CO2from the CO2-containing air 101 is captured by contacting the CO2-containing air 101 with the CO2capture solution 114 in the gas-liquid contactor 100. The CO2from the CO2-containing air 101 can react with the basic CO2capture solution 114, for example, to form the CO2-containing capture solution 111. In some embodiments, the CO2capture solution 114 comprises an alkali metal hydroxide, and the CO2is absorbed by reacting with the alkali metal hydroxide to form a carbonate-rich capture solution (e.g., K2CO3, Na2CO3, or a combination thereof). The CO2-containing capture solution 111 can include the carbonate-rich capture solution, and is therefore sometimes referred to herein as the “carbonate-rich capture solution 111.” The CO2-containing capture solution 111 can be processed to recover the captured CO2for downstream use and to regenerate the alkali metal hydroxide for use in the CO2capture solution 114. In some embodiments, the recovered CO2may be transported downhole and sequestered in a geological formation, a subsurface reservoir, a carbon sink, or the like. In some embodiments, the recovered CO2may be used to enhance oil recovery by injecting the recovered CO2into one or more wellbores to increase the production of hydrocarbons from a reservoir. In some embodiments, the recovered CO2may be fed to a downstream fuel synthesis system, which can include a syngas generation reactor.

[0116] The CO2-containing capture solution 111 can also include lesser amounts of other components, such as hydroxide ions, alkali metal hydroxides (e.g., KOH, NaOH), water, and impurities. For example, the carbonate-rich capture solution 111 can comprise 0.4 M to 6 M K2CO3and 1 M to 10 M KOH. In another embodiment, the carbonate-rich capture solution 111 can include an aqueous Na2CO3-NaOH mixture. In some embodiments, the carbonate-rich capture solution 111 can include a mixture of K2CO3and Na2CO3.

[0117] The capture kinetics of CO2 from the CO2-containing air 101 to form carbonates can be improved by introducing an additive (such as a promoter substance) in the CO2 capture solution 114. Non-limiting examples of promoters for improving the capture of CO2 by carbonates include carbonic anhydrase, amines (primary, secondary, tertiary), zwitterionic amino acids, and boric acid. The resulting carbonate-rich capture solution 111 produced by the gas-liquid contactor 100 includes carbonates and bicarbonates, and also includes the promoter. An exemplary composition of such carbonate-rich capture solution 111 can include K2CO3 / KHCO3 and a promoter. The carbonate-rich capture solution 111 produced from such CO2 capture solution 114 can have a pH in the range of 11-13, and can have little residual hydroxide from the CO2 capture solution 114. In some cases, additives that are not considered promoters can be used to improve the absorption of CO2 in the CO2 capture solution 114.

[0118] Reference is made to Figure 1 , the gas-liquid contactor 100 includes a housing 102. The housing 102 defines a portion of the body of the gas-liquid contactor 100 and provides structure thereto. The housing 102 includes an outer structure or wall that partially encloses any combination of structural members 115 interconnected. The structural members 115 provide structural support and stability to the gas-liquid contactor 100, and provide a body for supporting components of the gas-liquid contactor 100 within the housing 102. The structural members 115 can include, but are not limited to, walls, panels, beams, frames, and the like. The housing 102 can also include other portions, such as cladding, panels, and the like, that help to enclose some portions of the housing 102 and define an outer shell of the housing 102. The housing 102 at least partially encloses and defines an interior 113 of the housing 102. The interior 113 of the housing 102 is the internal volume or interior space in which components of the gas-liquid contactor 100 reside. The housing 102 also includes openings 103 that allow gas to move into and out of the gas-liquid contactor 100. For example, and with reference to Figure 1 , the housing 102 has one or more inlets 1031. In Figure 1 embodiments, the one or more inlets 1031 are formed by the openings 103, such that the inlets 1031 can be referred to herein as one or more inlet openings 1031 through which the CO2-containing air 101 enters the interior 113 of the housing 102. The housing 102 has one or more outlets 1030. In Figure 1 embodiments, the one or more outlets 1030 are formed by the openings 103, such that the outlets 1030 can be referred to herein as one or more outlet openings 1030 through which the CO2-lean gas 105 exits the interior 113 of the housing 102. In Figure 1In an exemplary embodiment of the gas-liquid contactor 100, the housing 102 defines two inlets 103I and one outlet 103O. The outlet 103O may be defined by components of the gas-liquid contactor 100. For example, in... Figure 1 In one embodiment of the gas-liquid contactor 100, the gas-liquid contactor 100 has an upright-oriented fan duct 107. The fan duct 107 extends upward from the housing 102 and facilitates the exhaust of lean CO2 gas 105. An outlet 103O is positioned along the fan duct 107. In such an embodiment, CO2-containing air 101 enters the interior 113 of the housing 102 in a substantially horizontal direction through one or both inlets 103I, and lean CO2 gas 105 exits the interior 113 in a substantially vertical direction through the outlet 103O. The outlet 103O is located at the upper end of the fan duct 107. In embodiments of the gas-liquid contactor 100 without the fan duct 107, the outlet 103O may be located elsewhere. Other configurations of the inlets 103I and outlet 103O of the housing 102 are possible.

[0119] The housing 102 at least partially surrounds and protects the components of the gas-liquid contactor 100 located within the interior 113 of the housing 102. An example of such a component is the packing section 106, which is protected by the housing 102 from the influence of the surrounding atmosphere. Figure 1 As shown, one or more packing sections 106 (sometimes collectively referred to herein as "packing 106" or "packing 106") are located within the interior 113 adjacent to one or more inlets 1031. At this location, the one or more packing sections 106 receive CO2-containing air 101 entering the interior 113 via one or more inlets 1031. The one or more packing sections 106 are used to increase the transfer of CO2 present in the CO2-containing air 101 to the trapping solution 114, because the one or more packing sections 106 provide a large surface area for dispersion on the trapping solution 114, thereby increasing the reaction area between the CO2-containing air 101 and the trapping solution 114. The trapping solution 114 converts the CO2-containing air 101 into CO2-lean gas 105, which is discharged from one or more outlets 1030 of the gas-liquid contactor 100. The packing section 106 receives the CO2 trapping solution 114 and facilitates the absorption of CO2 present in the CO2-containing air 101 into the CO2 trapping solution 114 on the packing section 106, as described in more detail below.

[0120] refer to Figure 1, one possible arrangement of the packing section 106 includes two or more packing sections 106A, 106B. Each packing section 106A, 106B is located downstream of and proximate to one of the inlets 1031. The packing sections 106A, 106B are spaced apart from each other within the housing 102. The direction in which the packing sections 106A, 106B are spaced apart is parallel to the direction in which the CO2-containing air 101 flows through the packing sections 106A, 106B. The space or volume defined between one or more structural members of the packing sections 106A, 106B and / or the housing 102 is a plenum 108. The sides of the plenum 108 are the packing sections 106A, 106B. The plenum 108 is a void or space within the housing 102 into which gas (e.g., the CO2-lean gas 105) flows downstream of the packing sections 106A, 106B and from which the CO2-lean gas 105 flows out of the housing 102 through the outlet 1030. The plenum 108 is part of the interior 113 of the housing 102. The volume of the plenum 108 is less than the volume of the interior 113. In some embodiments, the volume of the interior 113 of the housing 102 is approximately equal to the combined volume of the packing sections 106A, 106B and the plenum 108. Referring to Figure 1 , the packing sections 106A, 106B are positioned along the same horizontal plane as the plenum 108, or along the same lower horizontal plane as the plenum 108. Referring to Figure 1 , the plenum 108 can include an upper plenum portion 108U that is the uppermost portion of the plenum 108, and a lower plenum portion 108L that is the lowermost portion of the plenum 108. The total height of the plenum 108 is defined as the height of the upper plenum portion 108U plus the height of the lower plenum portion 108L. A portion of the upper plenum portion 108U is defined by a housing plenum wall 102W of the housing 102, and the remainder of the upper plenum portion 108U is defined by the portion of the fan airway 107 that is located below the fan 212. The housing plenum wall 102W extends upward from the remainder of the housing 102. In some embodiments, and referring to Figure 1 , the housing plenum wall 102W is the uppermost portion of the housing 102. The height of the upper plenum portion 108U includes a lower height portion defined by the housing plenum wall 102W and an upper height portion defined by the portion of the fan airway 107 that is located below the fan 212. In some embodiments, the lower height portion defined by the housing plenum wall 102W is two-thirds of the height of the upper plenum portion 108U, and the upper height portion defined by the portion of the fan airway 107 that is located below the fan 212 is one-third of the height of the upper plenum portion 108U. This configuration of the upper plenum portion 108U can reduce re-ingestion of the partially CO2-lean gas 105 at the inlets 1031. Referring to Figure 1A portion of the upper plenum portion 108U, and thus a portion of the plenum 108, extends into the fan airway 107 or the cowling. After the C02-containing air 101 flows through the packing sections 106A, 106B, the C02-lean gas 105 flows through the plenum 108 before being discharged to the ambient environment. In other embodiments of the gas-liquid contactor 100, there is no plenum. The gas-liquid contactor 100 can include one or more portions of a drift eliminator to remove or reduce C02 capture solution 114 that can be entrained in the C02-lean gas 105 flowing through the plenum 108.

[0121] In Figure 1 In the exemplary embodiment of the gas-liquid contactor 100 of the'1 1 1 patent, the C02-containing air 101 enters the interior 1 13 of the housing 102 through two inlets 1031 in a substantially horizontal direction. The C02-containing air 101 then flows through the packing sections 106A, 106B in a substantially horizontal direction, where the C02 present in the C02-containing air 101 contacts the C02 capture solution 1 14 present on the packing sections 106A, 106B and / or flowing through the packing sections 106A, 106B in a substantially downward direction. The exposed surface of the liquid film on the packing sections 106A, 106B is the gas-liquid interface between the C02-containing air 101 and the C02 capture solution 1 14. The C02 from the C02-containing air 101 is absorbed into the liquid film to form C02-containing capture solution 1 1 1 and C02-lean gas 105. The C02-containing capture solution 1 1 1 flows out of the packing sections 106A, 106B in a downward direction in a mixed solution with unreacted C02 capture solution 1 14 and is collected. The C02-containing air 101 treated by the packing sections 106A, 106B exits the packing sections 106A, 106B as C02-lean gas 105. The C02-lean gas 105 from both packing sections 106A, 106B is collected in the plenum 108 and then flows out of the plenum 108 in a vertically upward direction through an outlet 1030. Figure 1 The gas-liquid contactor 100 of the'1 1 1 patent can be considered a dual cell (due to the two packing sections 106A, 106B) crossflow air contactor. Other configurations of the gas-liquid contactor are possible, as described in more detail below.

[0122] Each packing section 106 defines a packing depth 106D, which represents the distance that the C02-containing air 101 travels as it flows through the packing section 106. The packing depth 106D can be in the range of 2-10 meters. Each packing section 106 also defines a packing liquid travel dimension 106L (sometimes referred to herein as "packing LTD 106L"), which represents the distance that the capture solution 1 14 travels as it flows through the packing section 106. In the exemplary embodiment of the gas-liquid contactor 100 of the'1 1 1 patent, the packing depth 106D is transverse to the packing LTD 106L. In other embodiments of the gas-liquid contactor 100, the packing depth 106D is parallel to the packing LTD 106L. Figure 1 Figure 1 ​In the gas-liquid contactor 100, the packing depth 106D is defined in a substantially horizontal direction, and the packing LTD 106L is a vertical dimension. In some embodiments, the packing LTD 106L (e.g., the height of each packing segment 106) is greater than 2 m. In some embodiments, the packing LTD 106L is greater than 5 m. In some embodiments, the packing LTD 106L is between 2 m and 20 m. In some embodiments, the packing depth 106D is greater than 3 m. In some embodiments, the packing depth 106D is greater than 5 m. In some embodiments, the packing depth 106D is between 3 m and 10 m. In other configurations of the gas-liquid contactor 100, the packing depth 106D and the packing LTD 106L can be defined differently, as described in more detail below.

[0123] Referring to Figure 1 Each packing segment 106 includes one or more structured packings 116. In Figure 1 In embodiments of the packing segment 106, each packing segment 106 includes a plurality of structured packings 116. Within one of the packing segments 106, each structured packing 116 is arranged adjacent to another structured packing 116. The structured packings 116 of each packing segment 106 can be arranged adjacent to one another in one or more of the directions of the packing depth 106D, the packing LTD 106L, and a direction perpendicular to both the packing depth 106D and the packing LTD 106L. Within one of the packing segments 106, in some embodiments, one structured packing 116 is attached to another structured packing 116. Within one of the packing segments 106, in some embodiments, the structured packings 116 of each packing segment 106 are arranged adjacent to one another with minimal spacing or gap in one or more of the directions of the packing depth 106D, the packing LTD 106L, and a direction perpendicular to both the packing depth 106D and the packing LTD 106L.

[0124] Referring to Figure 1 Some of the structured packings 116 of each packing segment 106 are mounted to one or both of: 1) the structural member 115 of the housing 102, and 2) at least one other structured packing 116. This support of the structured packings 116 strengthens their arrangement within each packing segment 106, helps to rigidify each packing segment 106, and can also help each structured packing 116 to resist or support loads acting thereon during operation of the gas-liquid contactor 100. For example, in mounting the structured packings 116 as described above, the structured packings 116 become constrained, which can result in an increase in the overall strength (e.g., crush strength) of each structured packing 116 and each packing segment 106 compared to an unconstrained packing structure.

[0125] The structured packing 116 can be arranged to form packing sections 106 of any desired shape or configuration. For example, referring to Figure 1 , the structured packing 116 is arranged such that each packing section 106A, 106B includes at least one arrangement 118 of structured packing 116. In Figure 15 , each packing section 106A, 106B includes two arrangements 118 of structured packing 116 - an upper arrangement 118U and a lower arrangement 118L. The structured packing 116 of each arrangement 118 can be arranged adjacent to one another in one or more of the directions of packing depth 106D, packing LTD 106L, and perpendicular to both the packing depth 106D and the packing LTD 106L. All of the structured packing 116 of each upper arrangement 118U is located above all of the structured packing 116 of each lower arrangement 118L. Each arrangement 118 can be considered a “slab” of packing. Other configurations of each arrangement 118 and positioning of the arrangements 118 of each packing section 106 are possible. Thus, Figure 1 , the packing sections 106A, 106B of

[0126] In the example embodiment of the packing sections 106 of Figure 1 , each packing section 106A, 106B has a respective packing section height that is substantially equal to the height of the inlet 103I. Providing packing sections 106 having substantially the same height as the height of the inlet 103I can help prevent or reduce the ability of the CO2-containing air 101 to bypass the packing sections 106 (e.g., flow around the packing sections 106), thereby helping to ensure that the packing sections 106 treat the maximum possible volume of the CO2-containing air 101. For “substantially equal” or “substantially the same,” it is understood that the values of the heights are approximately equal, with any differences being minimal as compared to the overall height dimension, which can be caused by manufacturing tolerances, packing installation requirements, and / or dimensional adjustments to allow for the presence of seals, baffles, or other features. Other configurations of the packing sections 106 are possible. For example, in another embodiment, the packing sections 106A, 106B have a height that is less than the height of the inlet 103I, and any gaps between the packing sections 106A, 106B and the housing 102 are sealed using suitable techniques.

[0127] Referring to Figure 1 , the gas-liquid contactor 100 has a liquid distribution system 120, including components of the liquid distribution system 120 or functionally connected to the liquid distribution system 120. The liquid distribution system 120 operates to move, collect, and distribute the CO2capture solution 114 and / or the CO2-containing capture solution 111. At least some features of the liquid distribution system 120 are supported by the housing 102. InFigure 1 In exemplary embodiments of the gas-liquid contactor 100, the support provided by the housing 102 includes structural support, as components of the liquid distribution system 120 are structurally supported by the housing 102, e.g., by the structural member 115, such that loads generated by these components are supported by the housing 102. Some or all features of the liquid distribution system 120 can be part of the gas-liquid contactor 100, or part of a DAC system (e.g., a DAC system 1200 of Figure 1

[0128] Referring to Figure 1 , the liquid distribution system 120 includes one or more liquid collection devices 109. Each liquid collection device 109 is configured to receive one or both of the CO2 capture solution 114 and the CO2-containing capture solution 111, and to hold a certain volume of it, temporarily or for a longer duration, thereby serving as a source of the CO2 capture solution 114 and / or the CO2-containing capture solution 111. Each liquid collection device 109 can have any configuration or be made of any material suitable for achieving the functions described in this specification. For example, one or more of the liquid collection devices 109 can be open-topped, or partially or completely covered. In Figure 1 , one or more of the liquid collection devices 109 includes a basin or is in the form of a basin. Other configurations of the liquid collection devices 109 are possible, such as a reservoir, a fluid bed, a sheet, a conduit, a vessel, a receiver, a network of pressurized tubes with openings or nozzles, or any other device capable of holding a liquid.

[0129] The liquid collection devices 109 of the liquid distribution system 120 include one or more top basins 104 and one or more bottom basins 110. The top basins 104 are supported by the housing 102. In some embodiments, the top basins 104 are formed by portions of the housing 102. The top basins 104 are configured to at least partially enclose or store the CO2 capture solution 114. Referring to Figure 1 , the top basins 104 are each positioned at least partially above the packing section 106. Referring to Figure 1 , the top basins 104 are positioned above the inlet 1031. Referring to Figure 15 ​The top tanks 104 are positioned below the upper plenum portion 108U. Thus, a portion of the plenum 108 (e.g., the upper plenum portion 108U) extends beyond or above the top tanks 104. While stored (at least temporarily) within the top tanks 104, the CO2 capture solution 114 is positioned to circulate (e.g., by pumping, gravity flow, or both) downward, through the packed sections 106, and ultimately into the bottom tanks 110. While the CO2 capture solution 114 is circulated through the packed sections 106, the CO2-containing air 101 is circulated through the packed sections 106 to contact the CO2 capture solution 114, through the plenum 108, and as the CO2-lean gas 105 to the ambient environment. By contacting the CO2-containing air 101 and the liquid CO2 capture solution 114, a process stream is formed, where the process stream is or includes a CO2-containing capture solution 111 having CO2 absorbed from the CO2-containing air 101 by the CO2 capture solution 114. The top tanks 104 can each have any suitable form or features for distributing the CO2 capture solution 114 over the packed sections 106. In Figure 1 In the example embodiment of the gas-liquid contactor 100 of FIG. 1, the liquid collection devices 109 include two top tanks 104. Each top tank 104 is positioned above one of the packed sections 106A, 106B to distribute the CO2 capture solution 114 to the respective packed section 106A, 106B. Figure 1 The top tanks 104 of FIG. 1 are fluidly isolated from one another (e.g., there is no fluid communication between the two top tanks 104). Other configurations and numbers of top tanks 104 are possible. Other configurations for distributing the CO2 capture solution 114 over the packed sections 106 are possible. In one such possible configuration, one or more liquid collection devices 109 include or are in the form of a network of pressurized pipes having openings or nozzles that distribute the CO2 capture solution 114 over the uppermost portions of the packed sections 106.

[0130] Referring to FIG. 1, Figure 1 One or more bottom tanks 110 are positioned at the bottom of the gas-liquid contactor 100, opposite the top tanks 104. As shown in FIG. 1, the bottom tanks 110 are positioned below the lower plenum portion 108L. Thus, a portion of the plenum 108 (e.g., the lower plenum portion 108L) extends beyond or above the bottom tanks 110. While stored (at least temporarily) within the bottom tanks 110, the CO2 capture solution 114 is positioned to circulate (e.g., by pumping, gravity flow, or both) upward, through the packed sections 106, and ultimately into the top tanks 104. While the CO2 capture solution 114 is circulated through the packed sections 106, the CO2-containing air 101 is circulated through the packed sections 106 to contact the CO2 capture solution 114, through the plenum 108, and as the CO2-lean gas 105 to the ambient environment. By contacting the CO2-containing air 101 and the liquid CO2 capture solution 114, a process stream is formed, where the process stream is or includes a CO2-containing capture solution 111 having CO2 absorbed from the CO2-containing air 101 by the CO2 capture solution 114. The bottom tanks 110 can each have any suitable form or features for distributing the CO2 capture solution 114 over the packed sections 106. In Figure 1As shown, a bottom sump 110 is positioned below the packing section 106. The bottom sump 110 serves as a collection tank for the process stream (e.g., the CO2-containing capture solution 111). The CO2-containing capture solution 111, including the absorbed CO2, as well as unreacted CO2 capture solution 114, collects in the bottom sump 110 and can then be pumped or otherwise moved out of the bottom sump 110 for further processing. For example, at least a portion of the liquid collected in the bottom sump 110 can be treated and then pumped for redistribution over the packing section 106 for CO2 capture. In another possible implementation, some or all of the liquid collected in the bottom sump 110 is pumped to the top sump 104 without treatment for redistribution over the packing section 106 for CO2 capture. In another possible implementation, some or all of the liquid collected in the bottom sump 110 is pumped to components of a DAC system (e.g., the DAC system 1200 of Figure 1 The bottom sump 110 can be compatible with the containment structure and prevent loss of the various CO2 capture solutions 114, many of which have caustic, aggressive, or high pH properties. In some aspects, the bottom sump 110 can be lined or coated with one or more materials resistant to caustic-induced corrosion or degradation. In some implementations of the gas-liquid contactor 100, components can be kept out of the bottom sump 110 that contains the CO2 capture solution 114. Additionally, the gas-liquid contactor 100 can be designed to keep most or all of the structural components out of the wettable areas of the gas-liquid contactor 100, e.g., any portion of the gas-liquid contactor 100 that comes into contact with the CO2 capture solution 114. Examples of wettable areas of the gas-liquid contactor 100 include components that support the packing section 106. Figure 1 A single bottom sump 110 is depicted. However, other configurations and numbers of bottom sumps 110 are possible.

[0131] In some implementations, the gas-liquid contactor 100 includes a vertically segmented packing section 106 in which the CO2 capture solution 114 is redistributed between vertically spaced packings. For example, and with reference to Figure 1 The liquid collection device 109 of the liquid distribution system 120 includes one or more redistribution sumps 119. The one or more redistribution sumps 119 are each positioned in a redistribution interval defined between the upper arrangement 118U and the lower arrangement 118L of each packing section 106A, 106B. The redistribution interval is a vertically extending gap defined between the upper arrangement 118U and the lower arrangement 118L of each packing section 106A, 106B. Each packing section 106A, 106B includes a redistribution sump 119 positioned in the redistribution interval of the packing section 106A, 106B. Thus, in Figure 1In the construction of the packing sections 106A, 106B, each redistribution trough 119 divides each packing section 106A, 106B into at least a top section (e.g., the upper arrangement 118U of structured packing 116) and a bottom section (e.g., the lower arrangement 118L of structured packing 116). Each redistribution trough 119 is positioned vertically between one or more top and bottom troughs 104, 110. During operation of the gas-liquid contactor 100, a process stream including CO2-containing capture solution 111 containing absorbed CO2 and unreacted CO2 capture solution 114 flows out of each upper arrangement 118U of structured packing 116 and collects in each redistribution trough 119. While stored (at least temporarily) within the redistribution trough 119, the process stream is positioned to be redistributed downward (e.g., by pumping, gravity flow, or both) through the remaining structured packing 116 of the lower arrangement 118L and ultimately into the bottom trough 110. In some embodiments, the process stream is pumped from the bottom trough 110 into the redistribution trough 119. The redistribution pools 119 can each have any suitable form or feature for redistributing the process stream over the structured packing 116 of the lower arrangement 118L. Non-limiting examples of features of the redistribution troughs 119 include trough walls, redistribution holes, and redistribution nozzles. Thus, in the gas-liquid contactor 100, there can be a collector / distributor system between vertical sections of packing that collects fluid flowing from above and redistributes it evenly to the packing below. The description of features of the top and bottom troughs 104, 110 and one, some, or all of the advantages and functions apply to the redistribution troughs 119 with necessary modifications.

[0132] In alternative embodiments in which the CO2 capture solution 114 is redistributed between vertically spaced packing, the packing sections 106 themselves include redistribution features. The redistribution features can be part of a redistribution packing that is distinct from the structured packing 116. The redistribution packing can have a vertical extent and be positioned between the arrangements 118U, 118L of structured packing 116, e.g., halfway through the packing LTD 106L. Alternatively, the redistribution packing can include multiple redistribution packing sections that alternate with the arrangements 118U, 118L of structured packing 116. The redistribution features facilitate redistribution of the CO2 capture solution 114 to the lower portion of the packing section 106. In alternative embodiments of the gas-liquid contactor 100, the gas-liquid contactor 100 does not include vertically sectioned packing or redistribution.

[0133] Reference is made to Figure 1In another possible implementation, the CO2 capture solution 114 flows through the packing section 106 in a direction opposite the average direction, also referred to as a "counter-current flow" configuration, where the CO2-containing air 101 is circulated through the packing section 106 in the average direction. In another possible implementation, the CO2 capture solution 114 flows through the packing section 106 in a direction parallel to the direction in which the CO2-containing air 101 is circulated through the packing section 106, also referred to as a "co-current flow" configuration. In another possible configuration, the CO2 capture solution 114 flows through the packing section 106 according to a combination of one or more of the cross-current flow, counter-current flow, and co-current flow configurations.

[0134] The gas-liquid contactor 100 can include supports within the packing section 106 between the top trough 104 and the bottom trough 110. For example, the packing section 106 can include additional supports, such as one or more structural members 115, for a particular portion of the packing section 106, such as for an upper portion of the packing section 106, such that a load (e.g., the weight of the portion of structured packing 116 when dry plus the weight of the liquid holdup of the CO2 capture solution 114 on the portion of structured packing 116) is not borne on another portion of the packing section 106, such as a bottom portion of the packing section 106. In some aspects, the packing section 106 can not include supports. In some aspects, at least one structural support can be located between the structured packing 116 of the packing section 106.

[0135] The liquid distribution system 120 can include any suitable components, such as pipes, flow restrictions, pumps, valves, manifolds, etc., fluidly coupled in any suitable arrangement, to achieve the functionality attributed to the liquid distribution system 120 herein. One non-limiting example of such components is one or more pumps 122, examples of which are illustrated in FIG. 1. Figure 1Pumps 122 are used to move liquids (e.g., CO2capture solution 114 and / or CO2-containing capture solution 111) from their sources to where they are used under pressure. Some non-limiting examples of possible functions of pumps 122 include moving CO2capture solution 114 to top tank 104, moving process stream from bottom tank 110 to redistribution tank 119, moving CO2capture solution 114 and / or CO2-containing capture solution 111 from bottom tank 110 to top tank 104 for redistribution over packing section 106, moving CO2capture solution 114 and / or CO2-containing capture solution 111 from bottom tank 110 to components of DAC system 1200 for further processing, and any combination of the foregoing processes. Thus, pumps 122 can be used to move liquids to, from, and within gas-liquid contactor 100.

[0136] A control system (e.g., control system 999 shown in FIG. 1) can be used to control the flow of fluids through pumps 122 of liquid distribution system 120. For example, the control system can be used to control pumps 122 so as to pump CO2capture solution 114 from bottom tank 110 to top tank 104. Pumps 122 can also be controlled so as to provide a constant flow to liquid distribution system 120 regardless of changes in liquid flow throughout gas-liquid contactor 100. Figure 1

[0137] Pumps 122 can facilitate distribution of CO2capture solution 114 over packing section 106 at relatively low liquid flow rates, which can help reduce the cost associated with pumping or moving CO2capture solution 114. In addition, low liquid flow rates of CO2capture solution 114 over packing section 106 can result in lower pressure drops for CO2-containing air 101 as it flows through packing section 106, which reduces the energy requirements of devices (e.g., fan 212 described below) used to move CO2-containing air 101 through packing section 106. Pumps 122 can be configured to produce intermittent or pulsed flow of CO2capture solution 114 over packing section 106, which can allow relatively low liquid flow rates to be used to intermittently wet packing section 106. CO2capture solution 114 sprayed, flowed, or otherwise distributed over packing section 106 is collected in bottom tank 110 and can then be moved back to top tank 104 by pumps 122, or transmitted downstream for processing.

[0138] In some embodiments, and with reference to Figure 1 , one or more pumps 122 of liquid distribution system can be operable to cause CO2capture solution 114 to be moved at a flow rate in the range of 0.5 L / m 2 s to 10 L / m 2 ​The liquid loading flow rate of 2 L / m 2 s and 6 L / m 2 s. The unit of liquid loading flow rate L / m 2 s refers to a given volume of CO2 capture solution 114 that covers a given area of the packing section 106 per second. The given area of the packing section 106 can refer to the planar area of the top of the packing section 106, such as the area of the packing section 106 under the top tank 104 (i.e., the top of the packing section 106 as viewed from the top tank 104 downward). When determined using planar area, a liquid loading flow rate of 2 L / m 2 s means that the pump 122 is configured to flow the CO2 capture solution 114 through each packing section 106 such that each square meter of planar area of the packing section 106 receives 2 L of CO2 capture solution 114 per second. The given area of the liquid loading flow rate can not refer to the surface area of the structured packing 116. The liquid loading flow rate can indicate or reflect an initial flow condition of the CO2 capture solution 114 being applied to the top of the packing section 106. The liquid loading flow rate can not reflect subsequent flow conditions that exist below the packing section 106.

[0139] One or more flow control systems (e.g., control system 999) can be used to flow the liquid treatment stream in the gas-liquid contactor 100 and within any downstream treatment processes fluidically connected to the gas-liquid contactor 100. The flow control system can include one or more flow pumps (including or in addition to the pump 122), fans, blowers, or solid conveyors to move the treatment stream, one or more flow tubes through which the treatment stream flows, and one or more valves to regulate the flow of the treatment stream through the tubes. Each configuration described herein can include at least one variable frequency drive (VFD) coupled to the respective pump, which is capable of controlling at least one liquid flow rate. In some embodiments, the liquid flow rate is controlled by at least one flow control valve.

[0140] In some embodiments, the flow control system can be manually operated. For example, an operator can set the flow rate of each pump or transfer device and set the valve open or closed position to regulate the flow of the treatment stream through the pipes in the flow control system. Once the operator has set the flow rate and valve open or closed position for all of the flow control systems distributed across the system, the flow control system can flow the treatment stream at a constant flow condition, such as a constant volumetric flow rate or other flow condition. To change the flow condition, the operator can manually operate the flow control system, for example, by changing the pump flow rate or valve open or closed position.

[0141] In some embodiments, the flow control system can be operated automatically. For example, the flow control system can be connected to a computer or control system (e.g., control system 999) to operate the flow control system. The control system can include a computer readable medium that stores instructions (such as flow control instructions and other instructions) that are executable by one or more processors to perform operations, such as flow control operations. An operator can use the control system to set flow rates and valve open or closed positions for all flow control systems distributed across a facility. In such embodiments, the operator can manually change flow conditions by providing input via the control system. Further, in such embodiments, the control system can automatically (i.e., without manual intervention) control one or more flow control systems, for example, using a feedback system connected to the control system. For example, a sensor (e.g., a pressure sensor, a temperature sensor, or other sensor) can be connected to a pipe through which a process stream flows. The sensor can monitor a flow condition (e.g., a pressure, a temperature, or other flow condition) of the process stream and provide it to the control system. In response to the flow condition exceeding a threshold value (e.g., a threshold pressure value, a threshold temperature value, or other threshold value), the control system can automatically perform an operation. For example, if the pressure or temperature in the pipe exceeds a threshold pressure value or a threshold temperature value, respectively, the control system can provide a signal to a pump to reduce the flow rate, provide a signal to open a valve to relieve pressure, provide a signal to shut off the flow of the process stream, or other signal.

[0142] The gas-liquid contactor 100 has a gas circulation device for moving or circulating a gas stream into and out of the gas-liquid contactor 100. In the embodiment of the gas-liquid contactor 100 depicted in Figure 2A , the gas circulation device is a fan 212. The fan 212 is used to circulate a gas, such as ambient air, such that the fan 212 causes the CO2-containing air 101 to flow into the gas-liquid contactor 100, and thus the fan 212 causes the CO2-lean gas 105 to flow out of the gas-liquid contactor 100. Thus, the fan 212 is used to circulate the CO2-containing air 101 and the CO2-lean gas 105 in the manner described herein. With reference to Figure 2A , the fan 212 can rotate about a fan axis defined by a fan shaft. In the embodiment of the fan 212 depicted in Figure 2A , the fan shaft has an upright or vertical orientation. Other orientations of the shaft and fan axis are possible, as described in more detail below. With reference to Figure 2B , the fan 212 is positioned upstream of an end of the fan airway 107 defining the outlet 103O and is used to cause the CO2-lean gas 105 to flow through the outlet 103O. In another possible configuration, the fan 212 is positioned between the oppositely directed ends of the fan airway 107 and upstream of the outlet 103O such that the fan 212 causes the CO2-lean gas 105 to flow through the outlet 103O. With reference to Figure 2BThe fan 212 is positioned downstream and above the upper plenum portion 108U. Rotation of the fan 212 about the fan axis causes circulation of the gas into the inlet 103I and through the gas-liquid contactor 100. For example, in the embodiment of the gas-liquid contactor of Figure 2B In the embodiment of the gas-liquid contactor of

[0143] Other configurations of the gas-liquid contactor 100 are possible, some of which are now described in more detail.

[0144] In one such possible configuration, and with reference to Figure 2A The gas-liquid contactor 100a can have an upright body and an air inlet 2103 along the bottom through which the CO2-containing air 101 is allowed to enter the gas-liquid contactor 100a. The fan 2112 rotates to draw the CO2-containing air 101 in the upward direction through the inlet 2103 to contact the packing segment 2106. In the configuration of Figure 1 The gas-liquid contactor 100a has only one packing segment 2106, and can therefore be referred to as a "single cell" gas-liquid contactor 100a. The CO2 capture solution 114 is circulated within the packing 2106 by, for example, gravity flow, uniform or laminar flow, etc., and eventually flows into one or more bottom tanks 2110. As the CO2 capture solution 114 is circulated through and over the packing 2106, the CO2-containing air 101 flows upward (e.g., by the action of the fan 2112) through the packing 2106 to contact the CO2 capture solution 114. Thus, the flow of the CO2 capture solution 114 through the packing 2106 in Figure 2A The flow of the CO2 capture solution 114 through the packing 2106 in the gas-liquid contactor 100a is countercurrent (or counterflow) to the flow of the CO2-containing air 101 through the packing 2106. The packing liquid travel dimension along which the CO2 capture solution 114 flows through the packing 2106 is defined in the vertical direction and is the same as the packing depth along which the CO2-containing air 101 flows upward through the packing 2106. A portion of the CO2 in the CO2-containing air 101 is transferred to (e.g., absorbed by) the CO2 capture solution 114, and the fan 2112 moves the CO2-lean gas 105 out of the gas-liquid contactor 100a to the ambient environment. The CO2-rich solution flows into the at least one bottom tank 2110.

[0145] With reference to Figure 1Another possible configuration of the gas-liquid contactor 100b has an upright body and an inlet 3103 along an upright side through which the C02-containing air 101 is allowed to enter the gas-liquid contactor 100b. A fan 3112 rotates about a horizontal fan axis to draw the C02-containing air 101 through the inlet 3103 in a substantially horizontal direction to contact the packing section 3106. In another possible implementation of the gas-liquid contactor 100b, the fan 3112 is upstream of the packing section 3106 relative to the flow direction of the C02-containing air 101. In such an implementation, the gas-liquid contactor 100b employs forced ventilation, where the fan 3112 rotates about a horizontal fan axis to "push" the C02-containing air 101 through the inlet 3103 in a substantially horizontal direction to contact the packing section 3106. In Figure 3 In the configuration of FIG. 31, the gas-liquid contactor 100b has only one section of packing 3106, and thus can be referred to as a "single cell" gas-liquid contactor 100b. The C02-capture solution 114 is circulated within the packing 3106 by, for example, gravity flow, uniform or laminar flow, etc., and ultimately flows into one or more bottom sumps 3110. As the C02-capture solution 114 is circulated through the packing 3106, the C02-containing air 101 flows substantially horizontally (e.g., by the action of the fan 3112) through the packing 3106, thereby contacting the C02-capture solution 114. Thus, the flow of the C02-capture solution 114 through the packing 3106 in the structure Figure 3 of FIG. 31 is substantially perpendicular to the flow of the C02-containing air 101 through the packing 3106 of the structure. This configuration of the flows can be referred to as a "cross flow" configuration. The packing liquid travel dimension along which the C02-capture solution 114 flows through the packing 2106 is defined in the vertical direction, and is perpendicular to the packing depth along which the C02-containing air 101 flows horizontally through the packing 2106. A portion of the C02 within the C02-containing air 101 is transferred to the C02-capture solution 114, and the fan 3112 removes the C02-lean gas 105 from the gas-liquid contactor 100b to the ambient environment. The C02-rich solution flows into at least one bottom sump 3110.

[0146] Figure 4A and 2B The description of the features of the gas-liquid contactor 100 shown in Figure 1 apply, mutatis mutandis, to the features of the gas-liquid contactor 100 shown in Figure 3 and 2B .

[0147] Reference is made to Figure 3Each structured packing 116 includes or consists of a plurality of packing sheets 130 attached together to form the three-dimensional structured packing 116. The packing sheets 130 of each structured packing 116 can be made of any suitable material, or have any suitable configuration, to achieve the functionality imparted by the packing section 106 herein. Some or all of the packing sheets 130 can be made of PVC, which is relatively light, moldable, affordable, and resistant to degradation by many chemicals. The packing sheets 130 are arranged, configured, treated, or otherwise configured to facilitate the diffusion of the liquid CO2 capture solution 114 into a thin film on the surface of the packing sheets 130, which can enable the liquid CO2 capture solution 114 to be maximally exposed to CO2 present in the CO2-containing air 101. For example, the liquid-gas interface surface of one or more packing sheets 130 can be treated with a coating, have a shape or structure, and / or be made of a material that changes the surface energy of some portions of the packing sheet 130 (e.g., increases the surface energy) and / or reduces the contact angle of the liquid CO2 capture solution 114. For example, the hydrophilicity of the liquid-gas interface surface of one or more packing sheets 130 can be increased by applying a coating to increase the surface free energy. The coating can be applied to some or all of the structured packing 116 to make the structured packing 116 even more suitable for low liquid loading flow rates in the range of 0.5 L / m 2 s to 2.5 L / m 2 s. In this regard, reference is made to such surface treatment and modification described in U.S. Patent Application Publication No. 2022 / 0176312, the entirety of which is incorporated herein by reference. Such “film-type” packing sheets 130 are suitable for DAC systems because they have a more efficient mass transfer capacity per unit volume of packing space. For example, film-type packing provides a relatively high specific surface area to volume ratio, which is defined in units of m 2 / m 3 s. The high specific surface area helps to expose more CO2 to the surface of the CO2 capture solution 114, and also has cost and structural implications.

[0148] Figure 3One possible implementation of a packing sheet 130 of structured packing 116 is shown in FIG. 1. The packing sheet 130 supports and directs the CO2capture solution 114 as it flows along the packing sheet 130. The packing sheet 130 is shaped, sized, formed, and configured to facilitate the transfer of CO2from the CO2-containing air 101 to the CO2capture solution 114. Thus, the packing sheet 130 is a medium that is intended to optimize the process of CO2from the flowing atmospheric air being absorbed into the flowing CO2capture solution 114. Other packing sheets, such as those used in water cooling tower applications, are primarily used to transfer heat between water and atmospheric air with little or no mass transfer occurring between the constituent gases of the air stream and the water being cooled. With the optimization for CO2mass transfer as disclosed herein, the packing sheet 130 is able to achieve lower pressure losses of the air flowing through the packing sheet 130 and more optimized distribution of the CO2capture solution 114 compared to attempting CO2mass transfer with packing sheets optimized for heat transfer. The packing sheet 130 can be referred to using other terms similar to "sheet", such as panel, grid, board, and layer. In some crossflow implementations, the packing sheet 130 is also shaped, sized, formed, and configured to facilitate CO2transfer from the CO2-containing air 101 to the CO2capture solution 114 with low liquid loading rates (e.g., 0.5 L / m 2 s to 2.5 L / m 2 s) compared to the higher liquid loading rates (typically greater than 15 L / m 2 s) of crossflow water cooling tower applications.

[0149] Referring to Figure 1 , the packing sheet 130 has a body 132 that defines a portion of the body of the packing sheet 130 and provides structure thereto. As Figure 3As shown, the body 132 has a first side 134A and a second side 134B blocked on a side of the body 132 opposite the first side 134A. The body 132 has a leading edge 136A and a trailing edge 136B. When the packing sheet 130 is installed in the gas-liquid contactor 100, 100A, 100B, sometimes referred to herein as the “installed configuration” of the packing sheet 130, the leading edge 136A is the edge of the body 132 that first receives the CO2-containing air 101. The trailing edge 136B is the edge of the body 132 through which the CO2-containing air 101, depleted of some CO2, flows after passing through the body 132. Thus, the leading edge 136A and the trailing edge 136B are spaced apart such that they define an air travel depth 138D of the packing sheet 130 therebetween. The air travel depth 138D (sometimes referred to herein as the “ATD 138D”) is parallel to the primary direction along which the CO2-containing air 101 flows through the packing sheet 130 during operation of the gas-liquid contactor 100, 100A, 100B. The ATD 138D represents the distance that the CO2-containing air 101 travels as it flows through the body 132 from the leading edge 136A to the trailing edge 136B. The ATD 138D is a dimension greater than zero. In the construction of the packing sheet 130 of the crossflow gas-liquid contactor 100 intended for use in the CO2 capture process of Figure 3 Figure 1 The ATD 138D is a horizontal or lateral dimension such that the ATD 138D is related to the horizontal flow direction of the CO2-containing air 101. The body 132 has a thickness defined in a direction perpendicular to the plane defined by the body 132. The thickness of the body 132 can sometimes be referred to as its width.

[0150] Referring to Figure 3 the body 132 has a plurality of interconnecting edges connected to each other and / or to the leading edge 136A and the trailing edge 136B. In the packing sheet 130 of Figure 1 the interconnecting edges include an upper edge 136U extending between the leading edge 136A and the trailing edge 136B, and a lower edge 136L also extending between the leading edge 136A and the trailing edge 136B. The edges 136A, 136B, 136U, 136L define or bound the body 132, as well as the boundary between the first side 134A and the second side 134B. The upper edge 136A and the lower edge 136B are spaced apart such that they define a liquid travel dimension 138L of the packing sheet 130 therebetween. The liquid travel dimension 138L (sometimes referred to herein as the “LTD 138L”) is parallel to the primary direction along which the CO2 capture solution 114 flows along the packing sheet 130 during operation of the gas-liquid contactor 100, 100A, 100B. The LTD 138L represents the distance that the CO2 capture solution 114 travels as it flows through the body 132 from the upper edge 136U to the lower edge 136L. The LTD 138L is a dimension greater than zero. In the construction of the packing sheet 130 of the crossflow gas-liquid contactor 100 intended for use in the CO2 capture process of Figure 3 the ATD 138D is a horizontal or lateral dimension such that the ATD 138D is related to the horizontal flow direction of the CO2-containing air 101. The body 132 has a thickness defined in a direction perpendicular to the plane defined by the body 132. The thickness of the body 132 can sometimes be referred to as its width.​Figure 2A In the construction of the packing sheet 130, LTD 138L is a vertical dimension, such that the lower edge 136L is located below the upper edge 136U. Figure 2A In the construction of the packing strip 130, the packing strip 130 is intended for use in Figure 3 In the cross-flow gas-liquid contactor 100, LTD 138L indicates the height of the packing sheet 130.

[0151] refer to Figure 3 LTD 138L is larger than ATD 138D. Therefore, when installed... Figure 3 In the embodiment of the cross-flow gas-liquid contactor 100, Figure 3 The packing sheet 130 can be "higher" than its "depth". In some embodiments, ATD 138D is between 2 feet and 24 feet. In some embodiments, ATD 138D is between 2 feet and 5 feet. In some embodiments, ATD 138D is between 3 feet and 5 feet. In some embodiments, LTD 138L (e.g., the height of packing sheet 130 in some embodiments) is between 2 feet and 24 feet. In some embodiments, LTD 138L is between 4 feet and 7 feet. In one possible embodiment of packing sheet 130, ATD 138D is between 3 feet and 5 feet, and LTD 138L is between 4 feet and 7 feet. Such relatively large packing sheets 130, together with adjacent and attached other such large packing sheets 130, provide a structured packing 116 capable of liquid film distribution on its surface and providing a relatively high specific surface area to volume ratio (in m³ / s). 2 / m 3 (defined in units), where a high specific surface area helps to expose more CO2 to the surface of the CO2 trapping solution 114. In some embodiments, the thickness of the body 132 is one to two orders of magnitude smaller than one or both of the ATD 138D and LTD 138L of the body 132.

[0152] Other configurations of the packing sheet 130 are possible. For example, in Figure 13 In the counter-current gas-liquid contactor 100A, the leading and trailing edges are horizontally oriented, and the upper and lower edges are identical to the leading and trailing edges, respectively. Figure 13 In the counter-current gas-liquid contactor 100A, ATD and LTD can be equal and defined along the same axis. In another possible embodiment, when the packing sheet 130 is installed in the gas-liquid contactors 100, 100A, 100B, LTD 138L is smaller than ATD 138D.

[0153] refer to Figure 14 The main body 132 includes a mass transfer area 131. Figure 13In the filler sheet 130, the mass transfer zone 131 exists on or is disposed on both the first side 134A and the second side 134B. The mass transfer zone 131 defines some surface area of the body 132 between the leading edge 136A, the trailing edge 136B, the upper edge 136U, and the lower edge 136L. In Figure 13 In implementations of the filler sheet 130, the mass transfer zone 131 defines substantially all of the surface area of the filler sheet 130. The mass transfer zone 131 includes or is defined by a plurality of mass transfer microstructures 133. The mass transfer microstructures 133 are surface formations or features that exist on the body 132 that are shaped, sized, and configured to facilitate the transfer of CO2 from the CO2-containing air 101 to the CO2 capture solution 114. In Figure 14 In implementations of the filler sheet 130, the mass transfer zone 131 defines substantially all of the surface area of the filler sheet 130. The mass transfer zone 131 includes or is defined by a plurality of mass transfer microstructures 133. The mass transfer microstructures 133 are surface formations or features that exist on the body 132 that are shaped, sized, and configured to facilitate the transfer of CO2 from the CO2-containing air 101 to the CO2 capture solution 114. In

[0154] The term "microstructure" in the mass transfer microstructure 133 is understood in the art to mean a plurality of distinct surface features integral with the filler sheet 130, and is contrasted in the art with the term "macrostructure" which is larger in scale than the microstructure and generally affects the overall shape of the sheet. For example, a fill sheet can have a macrostructure to affect air flow through the fill sheet, and / or the fill sheet has a microstructure on its surface to affect the properties of liquid flow, such as liquid contact angle. Macrostructures can include patterns such as corrugations and grooves that affect the tendency of air to move along the sheet depending on air velocity and sheet stiffness. Microstructures are smaller scale patterns or structures that can reduce the apparent liquid contact angle and enable film flow of the trapped solution. Microstructures can be present on macrostructures, but macrostructures are generally not present on microstructures. The prefix "micro" is not understood in the art to mean micron-scale features.

[0155] Different mass transfer microstructures 133 are possible. For example, referring to Figure 13 and 14 One or more mass transfer microstructures 833 can include a first wall portion 833A extending toward a first apex 833B. Figure 13 and Figure 18A The mass transfer microstructure 833 of FIGS. 8 and 9 is shown in cross-section perpendicular to the leading edge 136A of the body 132. The first apex 833B is the farthest point of the mass transfer microstructure 833 on the side 134A, 134B of the body 132. Each mass transfer microstructure 833 has a second wall portion 833C extending from the first apex 833B to a second apex 833D on the other side 134B, 134A of the body 132. The second apex 833D is the farthest point of the mass transfer microstructure 833 on the other side 134B, 134A of the body 132. In Figure 18A In cross-section, an acute angle is formed between the first wall portion 833A and the second wall portion 833C joining at the first apex 833B and the second apex 833D.

[0156] Referring to Figure 18AOne or both of the first and second wall portions 833A, 833C includes at least one wall feature 833E extending outwardly from the respective wall portion 833A, 833C. The wall feature 833E can include a first wall feature 835A extending outwardly from the first wall portion 833A on the first side 134A of the body 132 and forming a corresponding recess on the second side 134B. A second wall feature 835B extends outwardly from the second wall portion 833C on the second side 134B and forms a corresponding recess on the first side 134A. In some embodiments, the wall feature 833E can be a compound wall feature. In such embodiments, and with reference to FIG. 8B, each wall feature 933E includes a plurality of bumps or protrusions 935 to increase the surface area and mass transfer microstructure 933 of the wall feature 933E. Regardless of their shape or configuration, the wall features 833E, 933E can increase the surface tension acting on the CO2 capture solution 114 as it flows along the corresponding mass transfer microstructure 833, 933, which can increase the amount of liquid holdup on the packing sheet 130 and the ability of the CO2 capture solution 114 to capture CO2 from the CO2-containing air 101. The wall features 833E, 933E can increase the specific surface area of the structured packing 116 while having minimal, if any, impact on the pressure drop of the CO2-containing air 101 flowing through the structured packing 116. The wall features 833E, 933E can form a repeating pattern of surface protrusions along the ATD 138D. In alternative embodiments, the wall features 833E, 933E can only be present on some mass transfer microstructures 833. The wall features 833E, 933E can be present along all or only a portion of the wall portions 833A, 833C, which are defined along the LTD 138L. The axis defined by each of the first and second wall features 835A, 835B can be transverse to one another. In some embodiments, and with reference to FIG. 8B, the wall features 933E can be located on the wall portions 933A, 933C of the mass transfer microstructure 933 between the ends of the mass transfer microstructure 933 (e.g., between the first and second vertices 933B, 933D). The wall features 933E can be understood to form the mass transfer microstructure 933 or be a microstructure on the mass transfer microstructure 933. Thus, Figure 4E Figure 18A 14 Figure 18A 14

[0157] Figure 18A 18B ​​​​​​​Another example configuration of a mass transfer zone 131 is provided, which is formed of or includes microstructures that are present on other microstructures. Referring to Figure 18B , the mass transfer microstructures 1833 include base microstructures 1833B and supplemental microstructures 1833S. The base microstructures 1833B, one of which is shown in dashed outline 1805 in Figure 18B , are arranged in a herringbone or V-shaped pattern. Each base microstructure 1833B extends along a major axis that is parallel to the LTD 138L. When viewed in a cross-section that is perpendicular to the plane of the body 132, the cross-sectional profile of the base microstructures 1833B is similar to the profile of the mass transfer microstructures 133 of Figure 18B , described in more detail below. Referring to Figure 18B , the supplemental microstructures 1833S are present on the base microstructures 1833B, one of which is shown in dashed outline 1807 in Figure 18B , having a different dash-dot line than the dashed line 1805. Each supplemental microstructure 1833S extends along a major axis that is parallel to the LTD 138L. Each supplemental microstructure 1833S is arranged in a herringbone or V-shaped pattern, as shown by the dashed outline 1807. Referring to Figure 18A , there are multiple supplemental microstructures 1833S present on each base microstructure 1833B.

[0158] Referring to Figure 18A , the supplemental microstructures 1833S protrude from the base microstructures 1833B on one of the first side 134A and the second side 134B of the body 132. In an example embodiment, referring to Figure 18AEach supplementary microstructure 1833S undulates as it extends over an adjacent basic microstructure 1833B. Each basic microstructure 1833B includes a first wall portion 1833A extending toward a first vertex 1833C. The first vertex 1833C is the farthest point of the basic microstructure 1833B on the sides 134A and 134B of the body 132. Each basic microstructure 1833B includes a second wall portion 1833D extending from the first vertex 1833C to a second vertex 1833E on the other sides 134B and 134A of the body 132. The second vertex 1833E is the farthest point of the basic microstructure 1833B on the other sides 134B and 134A of the body 132. In the aforementioned cross-section, an acute angle is formed between the first wall portion 1833A and the second wall portion 1833D, which join at the first vertex 1833C and the second vertex 1833E. Similar to each basic microstructure 1833B, each supplementary microstructure 1833S includes a first wall portion 1833SA and a second wall 1833SD connected at a first vertex 1833SC and a second vertex 1833SE on the same sides 134B and 134A of the body 132. The first wall portion 1833SA of each supplementary microstructure 1833S protrudes from the first wall portion 1833A of the corresponding basic microstructure 1833B in a direction perpendicular to the plane defined by the first wall portion 1836A. The second wall portion 1833SD of each supplementary microstructure 1833S protrudes from the second wall portion 1833D of the corresponding basic microstructure 1833B in a direction perpendicular to the plane defined by the second wall portion 1833D. The height of the first vertex 1833SC of each supplementary microstructure 1833S is greater than the height of the first vertex 1833C of the lower basic microstructure 1833B. The height of the first wall portion 1833SA and the second wall 1833SD of each supplementary microstructure 1833S is greater than the height of the first wall portion 1833A and the second wall portion 1833D of the underlying basic microstructure 1833B. In an exemplary embodiment, the height of each supplementary microstructure 1833S measured between its first vertex 1833SC and its second vertex 1833SE is less than the thickness of the corresponding basic microstructure 1833B measured between its first vertex 1833C and its second vertex 1833E. As described herein, all heights being compared are measured from a common reference point for the heights being compared, along a direction perpendicular to the plane of the body 132. In an exemplary embodiment, the thickness of each supplementary microstructure 1833S measured along a direction perpendicular to either the corresponding first wall portion 1833SA or the second wall portion 1833SD is less than the height of the corresponding basic microstructure 1833B measured between its first vertex 1833C and its second vertex 1833E. In an exemplary embodiment, reference... Figure 3each supplemental microstructure 1833S protrudes from a surrounding surface of an underlying base microstructure 1833B on one side 134A, 134B of the body 132 and forms a corresponding recess or indentation relative to the surrounding surface of the same base microstructure 1833B on the other side 134A, 134B of the body 132. In example embodiments, reference is made to Figure 3 When each supplemental microstructure 1833S extends over an adjacent base microstructure 1833B, it undulates by transitioning between a first apex 1833SC and a second apex 1833SE, while the base microstructure does not undulate by transitioning between its first apex 1833C and its second apex 1833E. In example embodiments, reference is made to Figures 4A to 4E The mass transfer microstructure 1833 can be viewed as a transition surface having a raised portion (i.e., the supplemental microstructure 1833S) and a lower portion (i.e., the portion of the base microstructure 1833B between two adjacent supplemental microstructures 1833S), rather than as being composed of the supplemental microstructure 1833S overlaid on the base microstructure 1833B.

[0159] Along the portion of the base microstructure 1833B over which the supplemental microstructure 1833S protrudes, the orientation of the base microstructure 1833B can be transverse or non-parallel to the orientation of the supplemental microstructure 1833S. For example, reference is made to Figure 3 A portion of one of the base microstructures 1833B1 has a base orientation axis 1850. Segments of the supplemental microstructure 1833S protruding from the same segment of the base microstructure 1833B1 each have a supplemental orientation axis 1852. The segments of the supplemental microstructure 1833S are spaced apart from each other along the segment of the base microstructure 1833B1 in a direction parallel to the base orientation axis 1850. Each supplemental orientation axis 1852 is transverse to the base orientation axis 1850 when viewed in a plane parallel to the body 132. Each supplemental orientation axis 1852 forms an angle Θ with the base orientation axis 1850 when viewed in a plane parallel to the body 132. In example embodiments, the angle Θ is greater than 0 degrees and less than 180 degrees. In example embodiments, the angle Θ is approximately 90 degrees. Thus, Figure 3 and 18B The mass transfer microstructure 1833 of FIGS. 18A-18B can be viewed as or include “opposed” microstructures 1833B, 1833S. Adjusting the angle Θ at which the base microstructure 1833B and the supplemental microstructure 1833S intersect can allow for adjusting the liquid flow characteristics along the filler sheet 130. For example, if the value of the angle Θ is decreased (e.g., closer to 0 degrees), the intersection of the base and supplemental microstructures 1833B, 1833S can be made to “flatten out,” which can help to slow the flow of the CO2 capture solution 114 along the LTD 138L. In example embodiments, reference is made toFigure 3 The segments of each base microstructure 1833B have an orientation parallel to the orientation of the segments of the supplemental microstructure 1833S, and the segments of the supplemental microstructure 1836S do not protrude from the same segments of the base microstructure 1833B.

[0160] The mass transfer microstructure 833 can facilitate the diffusion of the liquid CO2capture solution 114 into a film on the surface of the packing sheet 130 (sometimes referred to as a “wetting” phenomenon), which can maximize the exposure of the liquid CO2capture solution 114 to the CO2present in the CO2-containing air 101. The opposing base microstructure 1833B and supplemental microstructure 1833S can increase the liquid holdup on the packing sheet 130 and the ability of the CO2capture solution 114 to capture CO2from the CO2-containing air 101. In example embodiments, the mass transfer microstructure 833 is present along the entire mass transfer zone 131. In alternative embodiments, the mass transfer microstructure 833 can be present only on a portion of the mass transfer zone 131.

[0161] In alternative embodiments of the packing sheet 130, the mass transfer zone 131 is present or disposed on only one of the first side 134A and the second side 134B. In alternative embodiments of the packing sheet 130, the mass transfer zone 131 is present or disposed on some of one or both of the first side 134A and the second side 134B.

[0162] Reference is made to Figure 3 The body 132 has a plurality of reinforcing elements 140. Each reinforcing element 140 extends outwardly from one or both of the first side 134A and the second side 134B of the body 132. In Figure 3 In the packing sheet 130 of Figure 3 ), the reinforcing elements 140 extend outwardly from both the first side 134A and the second side 134B. In the color scheme of Figure 3 , the darker gray shading on the reinforcing elements 140 indicates that the shaded portion extends outwardly from the body 132 on the first side 134A, and the lighter gray shading on the reinforcing elements 140 indicates that the shaded portion extends outwardly from the body 132 on the second side 134B. This color scheme is used throughout the drawings for the sole purpose of explaining the features of the drawings, and does not limit the direction of extension of any feature. In some embodiments, the expression “extends outwardly” is used herein to mean that the feature is protruding or extending from a plane defined by the body 132, typically in a direction perpendicular to the plane.

[0163] Each reinforcement element 140 is an elongated body having an orientation parallel to the LTD 138L. The reinforcement elements 140 reinforce the packing sheet 130 against lateral or bending loads caused by the weight of the packing sheet 130 itself, liquid holdup of the CO2capture solution 114 on the packing sheet 130, any fouling present on the packing sheet 130, and / or other loads by supporting the packing sheet 130. Thus, the reinforcement elements 140 can be any structure that is elongated or extends parallel to the LTD 138L and that can support the loads described herein. The reinforcement elements 140 can have any arrangement, number, location, form, shape, or size to achieve the functions ascribed to them herein, and examples of possible configurations of the reinforcement elements 140 are described in more detail below. In some embodiments, and with reference to Figure 3 the reinforcement elements 140 are disposed on or adjacent to the mass transfer zone 131 and its mass transfer microstructure 133. In some embodiments, the reinforcement elements 140 contribute little or nothing to the transfer of CO2from the CO2-containing air 101 to the CO2capture solution 114. In alternative embodiments, the packing sheet 130 is free of reinforcement elements 140, and its strength against loads is obtained from the material and dimensions of the packing sheet 130 itself.

[0164] With reference to Figure 3 , the body 132 has a plurality of spacers 150 disposed on the mass transfer zone 131. Each spacer 150 extends outwardly from one or both of the first side 134A and the second side 134B of the body 132. In Figure 3 the packing sheet 130, the spacers 150 extend outwardly from both the first side 134A and the second side 134B. In Figure 3 the color scheme, the darker gray shading on the spacers 150 indicates that the shaded portion extends outwardly from the body 132 on the first side 134A, and the lighter gray shading on the spacers 150 indicates that the shaded portion extends outwardly from the body 132 on the second side 134B. The spacers 150 are spaced apart from one another on each side 134A, 134B of the body 132. With reference to Figure 3 , the spacers 150 are spaced apart from one another in a direction parallel to the LTD 138L. The packing sheet 130 can include multiple groups of spacers 150, where the spacers 150 of each group of spacers 150 are aligned parallel to the LTD 138L. With reference to Figure 3 , the spacers 150 are vertically spaced apart along the height of the packing sheet 130. With reference to Figure 3The spacers 150 are also spaced apart from each other in a direction parallel to ATD 138D. The spacers 150 help maintain separation between the mass transfer zones 131 of adjacent packing pieces 130 of the structured packing 116. The spacers 150 of one packing piece 130 are aligned and abutted with the spacers 150 of another packing piece 130, thereby defining an airflow channel or recess between adjacent packing pieces 130 through which CO2-containing air 101 can flow, as explained in more detail below. In some embodiments, the abutment spacers 150 of adjacent packing pieces 130 are glued or bonded together, thereby forming a structural connection between adjacent packing pieces 130. Reference Figure 3 The adjacent surfaces 152 of the spacer 150 have an elliptical or circular shape and are perfectly aligned with the adjacent surfaces 152 of the spacer 150 of the adjacent packing sheet 130 to which they are joined (see example). Figure 3 The spacers 150 may have any arrangement, number, location, form, shape, or size to achieve the functions attributed to them herein, and examples of possible configurations of the spacers 150 are described in more detail below. In some embodiments, the spacers 150 contribute little or no contribution to the transfer of CO2 from CO2-containing air 101 to the CO2 trapping solution 114.

[0165] Reference Figure 3 The spacers 150 are arranged in pairs 150P. Each pair 150P is spaced apart from another pair 150P along both LTD 138L and ATD 138D. (See reference) Figure 3 The spacer portion is aligned with 150P along LTD138L. (Reference) Figure 3 The spacer pairs 150P are aligned along ATD 138D. In an alternative embodiment, the spacer pairs 150P are misaligned, staggered, or offset on the body 132 of the packing sheet 130. The spacer portions 150 in each spacer pair 150P are spaced apart from each other in a direction parallel to ATD 138D. The distance between the spacer portions 150 in each spacer pair 150P is parallel to ATD 138D. In some embodiments, this distance is less than one-third of ATD 138D. In some embodiments, this distance is less than the diameter or dimension of one of the spacer portions 150. Reference Figure 3 The mass transfer microstructure 133 exists between the spacers 150 of each spacer pair 150P and on the body 132 between the spacer pairs 150P. (Reference) Figure 3 Each spacer pair 150P includes a first spacer 150 extending outward from a first side 134A of the body 132 (in Figure 3 The spacer portion 150 shown is a darker gray shade, and the second spacer portion 150 extends outward from the second side 134B (as shown in...).Figure 3 The spacing portions 150 are shown as having a lighter gray shading, also see Figure 3 ). Each spacing portion 150 is a hollow body (see, e.g. Figure 3 ), such that they form a corresponding recess on the other side of the body 132 from which they extend. Thus, each spacing portion 150 forms a protrusion on the side 134A, 134B of the body 132 and a recess on the other side 134B, 134A.

[0166] The packing sheet 130 is optimized to maximize the surface area available for CO2 transfer from the CO2-containing air 101 to the CO2 capture solution 114. When the packing sheet 130 is assembled into the structured packing 116 and the structured packing 116 forms a portion of the packing section 106 installed in the gas-liquid contactor 100, the leading edge 136A of each packing sheet 130 of the structured packing 116 is substantially parallel to the vertical axis 135 or plumb line. Thus, the leading edge 136A has a substantially vertical orientation in the installed configuration of the packing sheet 130. In some embodiments, with reference to Figure 3 , the leading edge 136A is substantially perpendicular to the ATD 138D of the packing sheet 130 and the packing depth 106D of each packing section 106. The air inlet side edge (e.g., the leading edge 136A) of each packing sheet 130 is substantially perpendicular to the primary direction of flow of the CO2-containing air 101 along the packing sheet 130. In some implementations, the term “substantially” means that the packing sheets 130 can be positioned such that their leading edges 136A are parallel to the vertical axis 135 when installed as part of each packing section 106, with the understanding that there can be slight deviations from the vertical due to the following non-exhaustive list of factors: manufacturing tolerances during production of the packing sheets 130, slight misalignments during assembly of the packing sheets 130 into the structured packing 116, slight misalignments during assembly of the structured packing 116 into the arrangement 118 of the structured packing 116, and damage to the packing sheets 130 during shipping, assembly, and installation. In some implementations, the term “substantially” means that the packing sheets 130 are designed such that their leading edges 136A are parallel to the vertical axis 135 when installed within a tolerance of less than 2 degrees from strict parallel.

[0167] The alignment of the leading edge 136A of the packing sheet 130 with the vertical axis 135 in its installed configuration contrasts with some packing sheets used in water cooling towers that are primarily used to transfer heat between water and the atmosphere. These cooling tower packing sheets are oriented in the cooling tower such that their leading edges have an offset angle Δ with respect to the vertical axis 135. The offset angle Δ is sometimes referred to as the “stacking angle,” or the stacking of the packing sheets is sometimes referred to as having a “forward lean.” For purposes of comparison, the offset leading edge of such a cooling tower packing sheet is shown in Figure 3The leading edge 137 is schematically shown as a dashed line. The offset angle Δ of this cooling tower packing can be approximately five to ten (5-10) degrees. Such a cooling tower packing forms this offset angle Δ with the vertical axis 135 to counteract the effect of higher-velocity lateral airflow on the vertically flowing water on the packing surface during operation. As water flows downwards along the packing, typically parallel to the vertical axis 135, higher-velocity air tends to push the water towards the outlet side or trailing edge of the packing due to friction at the air-water interface, particularly along the lower leading edge portion of the packing. This can cause this lower leading edge portion to dry out, thus becoming less usable for heat transfer. To eliminate this dry area, the cooling tower packing eliminates these lower leading edge portions by “tilting” it in the direction of airflow, such that the apex angle of the packing near the intersection of the leading edge 137 and the top edge is positioned closest to the air inlet of the cooling tower. The lower leading angle of these cooling tower packings near the intersection of the leading edge 137 and the bottom edge is the portion on the inlet side furthest from the air inlet of the cooling tower.

[0168] In DAC applications, packing strips 130 are installed in crossflow gas-liquid contactors 100. Compared to typical water cooling tower applications, crossflow gas-liquid contactors 100 operate at lower air velocities (e.g., between 0.1 m / s and 5 m / s), and there is no similar problem of a dry zone formed by air horizontally pushing liquid along the lower portion of the packing strips 130 adjacent to the leading edge 136A. Therefore, in this DAC application, the offset angle Δ of the cooling tower packing strips is detrimental to performance because it results in a lack of surface area adjacent to the leading edge, which would otherwise be available to facilitate the transfer of CO2 from CO2-containing air 101 to the CO2 trapping solution 114. This missing surface area at the leading edge can lead to a reduction in the overall efficiency of each packing section 106.

[0169] Figure 4 The packing sheet 130 does not have the "forward tilt" associated with the aforementioned cooling tower packing sheets. In other words, Figure 4 The offset angle Δ of the packing sheet 130 is approximately zero degrees. Therefore, as Figure 4 As shown, the packing sheet 130 has an additional leading edge surface region 139 near its leading edge 136A, which is defined between the leading edge 136A, the imaginary leading edge 137, and a portion of the lower edge 136L between the imaginary leading edge 137 and the leading edge 136A. The additional leading edge surface region 139... Figure 4The additional leading edge surface area 139 is indicative of the surface area present in the filler sheet 130 that is missing near the leading edge of some cooling tower filler sheets having similar dimensions but whose leading edge 137 forms an offset angle Δ relative to the vertical axis 135. Such cooling tower filler sheets can be compensated for the missing surface area along their leading edge by providing a leading trailing edge that increases the missing surface area along the trailing edge.

[0170] Given the relatively large number of filler sheets 130 in the gas-liquid contactor 100, the additional leading edge surface area 139 available to each filler sheet 130 at its leading edge 136A equates to a greater additional mass transfer surface along the leading edge 136A at the level of the gas-liquid contactor 100. This can be more clearly seen with reference to Table 1 below for offset angles Δ of 5 degrees and 10 degrees. Table 1 calculates the additional leading edge surface area 139 adjacent to the leading edge 136A. The additional leading edge surface area 139 is calculated for each filler sheet 130, each structured packing 116, each packing section 106, and the gas-liquid contactor 100. The following example dimensions and configurations of the filler sheets 130, structured packings 116, and packing sections 106 are provided for the purpose of explaining Table 1 only, and it is understood that other dimensions and configurations are possible:

[0171] 1) The ATD 138D and LTD 138L of each filler sheet 130 is 1 m (e.g., each filler sheet 130 is 1 m deep x 1 m high);

[0172] 2) Each filler sheet 130 has a mass transfer zone 131 present on all of its first side 134A and second side 134B;

[0173] 3) There are ten filler sheets 130 in each structured packing 116;

[0174] 4) There are 10 structured packings 116 in each packing section 106; and

[0175] 5) There are two packing sections 106 in the gas-liquid contactor 100.

[0176]

[0177] Table 1: Comparison of Additional Surface Area for Two Offset Angles

[0178] Accordingly, Table 1 shows that due to the leading edge 136A being substantially parallel to the vertical axis 135, in crossflow applications at relatively low air velocities, the additional leading edge surface area 139 available to each packing sheet 130 along its leading edge 136A extends past each structured packing 116, each packing section 106, and ultimately to the crossflow gas-liquid contactor 100. The additional leading edge surface area 139 includes additional wettable mass transfer surface area, which for each packing sheet 130, each structured packing 116, and each packing section 106, can result in more CO2 being absorbed in the CO2 capture solution 114. Due to the increased surface area, this additional mass transfer surface can increase the ratio of specific surface area to volume (in m 2 / m 3 defined in units) for each packing section 106, where a higher specific surface area is understood to result in more CO2 being exposed to the surface of the CO2 capture solution 114.

[0179] The packing sheets 130 without the offset angle Δ along their leading edge 136A can be designed and implemented according to performance characteristics (liquid loading, mass transfer capture efficiency, mechanical strength at maximum size, etc.) relevant to transferring CO2 from atmospheric air to a liquid capture solution in a crossflow configuration with lower air velocities. These performance characteristics can be different from those of some cooling tower packing sheets, which are optimized to transfer heat from water to air.

[0180] The leading edge 136A being substantially parallel to the vertical axis 135 can result in the packing sheets 130 being more rigid in the vertical direction compared to packing sheets with a non-zero offset angle Δ. When such packing sheets 130 are assembled into structured packings 116, the structured packings 116 are therefore able to withstand greater loads compared to structured packings that include packing sheets with a non-zero offset angle Δ.

[0181] In some implementations, other than the leading edge 136A, other features of the packing sheet 130 are also substantially parallel to the vertical axis 135 when the packing sheet 130 is installed in the gas-liquid contactor 100. For example, with reference to Figure 3 , the packing sheet 130 has one or more spacer alignment axes 150A. Each spacer alignment axis 150A extends between the upper edge 136U and the lower edge 136L on one or both of the first side 134A and the second side 134B of the packing sheet 130. Each spacer alignment axis 150A also extends between spacers 150 that are aligned with each other along the LTD 138L. When Figure 4 the packing sheet 130 is installed in the gas-liquid contactor 100, each spacer alignment axis 150A has a substantially vertical orientation. When Figure 4C the packing sheet 130 is installed in the gas-liquid contactor 100, each spacer alignment axis 150A is substantially parallel to the vertical axis 135. WhenFigure 4D When the packing sheets 130 are installed in the gas-liquid contactor 100, each spacer is aligned with the axis 150A and substantially parallel to the leading edge 136A. Therefore, and referring to... Figure 4 Each set of spacers 150 aligned along LTD 138L is also aligned with the vertical axis 135. For simplicity, Figure 5 Only one spacer alignment axis 150A is shown, but the packing sheet 130 may include multiple spacer alignment axes 150A, each spacer alignment axis 150A being substantially parallel to the vertical axis 135, wherein each spacer alignment axis 150A is spaced apart from the adjacent spacer alignment axis 150A along the direction of ATD 138D.

[0182] The reinforcing element 140 is an additional feature of the packing sheet 130, and when the packing sheet 130 is installed in the gas-liquid contactor 100, the reinforcing element 140 can be substantially parallel to the vertical axis 135. (Reference) Figure 4 The packing sheet 130 has one or more reinforcing elements aligned with an axis 140A. Each reinforcing element aligned with the axis 140A extends between an upper edge 136U and a lower edge 136L on one or both of the first side 134A and the second side 134B of the packing sheet 130. Each reinforcing element aligned with the axis 140A also extends between reinforcing elements 140 aligned with each other along LTD 138L. Figure 4B When the packing sheet 130 is installed in the gas-liquid contactor 100, each reinforcing element has a substantially perpendicular orientation aligned with axis 140A. When Figure 4B When the packing sheet 130 is installed in the gas-liquid contactor 100, each reinforcing element is aligned with axis 140A and substantially parallel to the vertical axis 135. Figure 4B When the packing sheet 130 is installed in the gas-liquid contactor 100, each reinforcing element is aligned with the axis 140A and substantially parallel to the leading edge 136A. Therefore, and referring to... Figure 4D Each set of reinforcing elements 140 aligned along LTD 138L is also aligned with the vertical axis 135. For simplicity, Figure 4D Only one reinforcing element alignment axis 140A is shown, but the packing sheet 130 may include multiple reinforcing element alignment axes 140A, each of which is substantially parallel to the vertical axis 135, wherein each reinforcing element alignment axis 140A is spaced apart from the adjacent reinforcing element alignment axis 140A along the direction of ATD 138D.

[0183] The mass transfer microstructure 133 is an additional feature of the packing sheet 130, which, when the packing sheet 130 is installed in the gas-liquid contactor 100, can be substantially parallel to the vertical axis 135. (Reference) Figure 4B, the packing sheet 130 has one or more microstructure alignment axes 133A. In Figure 4B the configuration where the mass transfer microstructures 133 are V-shaped structures extending along the LTD 138L, each microstructure alignment axis 133A extends between a maximum or minimum of one V-shaped structure on one or both of the first side 134A and the second side 134B of the packing sheet 130. When Figure 4B the packing sheet 130 is installed in the gas-liquid contactor 100, each microstructure alignment axis 133A has a substantially vertical orientation. When Figure 4B the packing sheet 130 is installed in the gas-liquid contactor 100, each microstructure alignment axis 133A is substantially parallel to the vertical axis 135. When Figure 4D the packing sheet 130 is installed in the gas-liquid contactor 100, each microstructure alignment axis 133A is substantially parallel to the leading edge 136A. For simplicity, Figure 4B only one microstructure alignment axis 133A is shown, but the packing sheet 130 can include multiple microstructure alignment axes 133A each substantially parallel to the vertical axis 135, with each microstructure alignment axis 133A spaced apart from an adjacent microstructure alignment axis 133A along the direction of the ATD 138D.

[0184] Figure 4D the packing sheet 130 has a rectangular shape. Like the leading edge 136A, the trailing edge 136B is substantially parallel to the vertical axis 135. The upper edge 136U and the lower edge 136L are both substantially perpendicular to the leading edge 136A and the trailing edge 136B. Thus, when Figures 4 to 4E the packing sheet 130 is installed in the crossflow gas-liquid contactor 100, the leading and trailing edges 136B have a substantially vertical orientation and the upper and lower edges 136U, 136L have a substantially horizontal orientation. In other configurations of the body 132, the packing sheet 130 can have more or fewer edges 136A, 136B, 136U, 136L than shown in Figure 4 . In such configurations, the edges 136 of the body 132 can intersect at non-zero, non-right angles.

[0185] In view of the foregoing, in at least one embodiment of the packing sheet 130 of Figure 4C one or more of the stiffening element alignment axes 140A, the spacer alignment axes 150A, the microstructure alignment axes 133A, and the trailing edge 136B are aligned with the leading edge 136A and substantially parallel to the vertical axis 135 in any combination. The expression "substantially parallel" means that the packing sheet 130 can be positioned such that these features are parallel to the vertical axis 135 when installed as part of each packing segment 106, with the understanding that there can be slight deviations from parallel as described above.

[0186] Reference is made to Figure 4D Body 132 has or defines a center of mass 132C. Center of mass 132C is also referred to as Figure 4 geometric center in a two-dimensional plane of body 132 as shown. Figure 4C Filler sheet 130 has a rectangular shape, and center of mass 132C is a point where diagonals of body 132 intersect. Filler sheet 130 and / or features thereof have point symmetry about center of mass 132C. When rotated 180 degrees about center of mass 132C, filler sheet 130 and its features look the same. Point symmetry of filler sheet 130 about its center of mass 132C can result from a zero degree offset angle D of filler sheet 130. Point symmetry of filler sheet 130 about its center of mass 132C can allow for abutment of attachment features (e.g., spacers 150 and abutment surfaces of stiffening elements 140) of adjacent filler sheets 130 to one another, which can facilitate formation of regular filler 116 by assembling multiple filler sheets 130. Point symmetry of filler sheet 130 about its center of mass 132C can allow for manufacturing of common filler sheets 130 of filler section 106 using a single tool (e.g., a mold), where adjacent attached filler sheets 130 of regular filler 116 are point symmetric translations of one another. This contrasts with forwardly pitched fill in some cross flow water cooling tower applications that consist of two or more types of filler sheets (e.g., “A” filler sheets and “B” filler sheets). In alternative embodiments, filler sheet 130 is not symmetric about its center of mass 132C. In alternative embodiments, each regular filler 116 includes one or more types of filler sheets 130.

[0187] Filler sheet 130 can have any number, shape, and / or arrangement of features to achieve the functionality of filler sheet 130 herein. For example, and with reference to Figure 4 Stiffening element 140 includes a middle stiffening element 142. Middle stiffening element 142 stiffens or strengthens body 132 along a middle portion of filler sheet 130. Middle stiffening element 142 stiffens or strengthens body 132 along the middle portion by supporting body 132 against lateral or bending loads and / or other loads described above. Middle stiffening element 142 includes a middle stiffener 142A. Middle stiffener 142A is located on body 132 between leading edge 136A and trailing edge 136B. For Figure 4D Filler sheet 130, middle stiffener 142A is located along a middle portion of body 132 between leading edge 136A and trailing edge 136B at a position that is half of ATD 138D from leading edge 136A. For Figure 4CThe packing sheet 130 has intermediate reinforcements 142A located between spacers 150 on either side of the intermediate reinforcements 142A in the ATD 138D along the middle of the body 132. The intermediate reinforcements 142A are positioned adjacent to each other along the LTD 138L to form intermediate reinforcing elements 142. The intermediate reinforcements 142A are positioned perpendicularly adjacent to each other along the middle of the packing sheet 130. Figure 4 The packing sheet 130 has one intermediate reinforcing element 142. In an alternative embodiment, the packing sheet 130 has two or more intermediate reinforcing elements 142.

[0188] The packing sheet 130 can be cut or segmented at the lateral midpoint (measured along ATD 138D) of the intermediate reinforcing element 142 to form a packing sheet 130 of desired size, which can be laterally aligned with the leading edge 136A or trailing edge 136B of an adjacent packing sheet 130 (e.g., so that one packing sheet 130 abuts against another packing sheet along their adjacent edges 136A, 136B). Figure 4 In an exemplary embodiment where the packing sheet 130 has a width of 4 feet measured from a vertical reference in a direction parallel to ATD 138D, and the intermediate reinforcing element 142 is 2 feet measured from the vertical reference, the packing sheet 130 can be vertically cut through the lateral midpoint of the intermediate reinforcing element 142 to produce two packing sheets 130, each having a width of 2 feet. The intermediate reinforcing element 142 is split to form leading or trailing edges 136A, 136B, such that the resulting two packing sheets 130 do not have the intermediate reinforcing element 142. Each of the two 2-foot packing sheets 130 can be combined with a packing sheet 130 of similar size to form a regular packing 116 with a width of 2 feet.

[0189] refer to Figure 4 , Figure 4 and Figure 4 Each intermediate reinforcement 142A extends outward from one of the first side 134A and the second side 134B. Each intermediate reinforcement 142A extends outward to a local maximum value, shown as an attachment wall 142B. Each attachment wall 142B defines a surface of the intermediate reinforcement 142A that is positioned further away from the plane of the body 132 than other portions of the intermediate reinforcement 142A. Each attachment wall 142B defines a surface of the intermediate reinforcement 142A that is further away from the mass transfer microstructure 133 than other portions of the intermediate reinforcement 142A. Figure 4C and Figure 5 In the color scheme, the darker gray shading on the reinforcing element 140 indicates that the shadow portion extends outward from the body 132 on the first side 134A, and the lighter gray shading on the reinforcing element 140 indicates that the shadow portion extends outward from the body 132 on the second side 134B.

[0190] In some embodiments, one or more of the attached walls 142B in adjacent filler pieces 130 are glued or bonded together, thereby forming a structural connection between adjacent filler pieces 130. Such attached walls 142B of the intermediate stiffeners 142A also help to space the adjacent filler pieces 130 apart from one another, thereby helping to define airflow channels between adjacent filler pieces 130 through which the CO2-containing air 101 can flow, as described in greater detail below. When adjacent filler pieces 130 are attached together in this manner, the attached intermediate stiffening elements 140 help to stiffen or reinforce the structured packing 116 along the middle portion of the structured packing 116, which can be helpful if each filler piece 130 has a relatively large ATD 138D (e.g., between 4 feet and 7 feet) and is configured for installation in a crossflow gas-liquid contactor 100.

[0191] Referring to Figure 5 , the intermediate stiffening elements 142 have an orientation that is substantially parallel to the leading edge 136A. The intermediate stiffeners 142A of the intermediate stiffening elements 142 are aligned with one another in a direction that is parallel to the LTD 138L. In some embodiments, an axis extending through the attached walls 142B of the intermediate stiffeners 142A is substantially parallel to the leading edge 136A of the filler piece 130. In some embodiments, an axis extending through the attached walls 142B of the intermediate stiffeners 142A is substantially parallel to the vertical axis 135.

[0192] The features of the filler piece 130 have a height defined in a direction that is perpendicular to a plane defined by the main body 132 (e.g., the reference plane 132D). The reference plane 132D is parallel to both the ATD 138D and the LTD 138L. Referring to Figure 5 and 4D , each attached wall 142B defines a stiffener height 142H, each mass transfer microstructure 133 defines a microstructure height 133H, and each spacer 150 defines a spacer height 150H. The reference plane 132D can be defined relative to any suitable common reference from which measurements are made. In some embodiments, the reference plane 132D corresponds to a piece plane of the main body 132 and is located at a midpoint of a distance measured between opposing peak portions of the mass transfer microstructures 133 on opposite sides of the main body 132.

[0193] The smallest of the stiffener height 142H, the microstructure height 133H, and the spacer height 150H is the microstructure height 133H. Referring to Figure 4 , the microstructure height 133H is measured relative to the reference plane 132D, which can be located on the first side face 134A or the second side face 134B of the main body 132. In embodiments in which the mass transfer microstructures 133 are V-shaped structures Figure 4CIn the configuration of FIG. 1, the microstructure height 133H is defined between the peak and the valley of each V-shaped structure. Referring to FIG. 1, the microstructure height 133H is measured relative to the reference plane 132D on the first side 134A of the body 132, because the adjoining surface 152 of the microstructure 133 is on the first side 134A of the body 132. Figure 5 In the configuration of FIG. 1, the reinforcement height 142H is measured relative to the reference plane 132D on the side 134A, 134B of the body 132 opposite the side 134A, 134B of the body 132 on which the attachment wall 142B of the intermediate reinforcement 142A is located. For example, in the configuration of FIG. 1, the reinforcement height 142H is measured relative to the reference plane 132D on the first side 134A of the body 132, because the attachment wall 142B of the intermediate reinforcement 142A is on the second side 134B of the body 132. Figure 5 In the configuration of FIG. 1, the reinforcement height 142H is measured relative to the reference plane 132D on the first side 134A of the body 132, because the attachment wall 142B of the intermediate reinforcement 142A is on the second side 134B of the body 132. Referring to FIG. 1, the reinforcement height 142H is measured relative to the reference plane 132D on the first side 134A of the body 132, because the attachment wall 142B of the intermediate reinforcement 142A is on the second side 134B of the body 132. Figure 5 In the configuration of FIG. 1, the reinforcement height 142H is measured relative to the reference plane 132D on the first side 134A of the body 132, because the attachment wall 142B of the intermediate reinforcement 142A is on the second side 134B of the body 132. Referring to FIG. 1, the reinforcement height 142H is measured relative to the reference plane 132D on the first side 134A of the body 132, because the attachment wall 142B of the intermediate reinforcement 142A is on the second side 134B of the body 132. Figure 5 In the configuration of FIG. 1, the reinforcement height 142H is measured relative to the reference plane 132D on the first side 134A of the body 132, because the attachment wall 142B of the intermediate reinforcement 142A is on the second side 134B of the body 132. Referring to FIG. 1, the reinforcement height 142H is measured relative to the reference plane 132D on the first side 134A of the body 132, because the attachment wall 142B of the intermediate reinforcement 142A is on the second side 134B of the body 132.

[0194] The reinforcement height 142H, the microstructure height 133H, and the spacer height 150H are different, such that each piece of packing 130 can be connected to and spaced apart from an adjacent piece of packing 130 of the structured packing 116. See FIG. 1. Figure 5 The spacer height 150H is greater than the microstructure height 133H when both heights are measured from the same reference plane 132D. See FIG. 1. Figure 5 and Figure 5A The reinforcement height 142H is greater than the microstructure height 133H when both heights are measured from the same reference plane 132D. In some implementations, and referring to FIG. 1, the reinforcement height 142H is greater than the microstructure height 133H. Figure 5A and Figure 5A The reinforcement height 142H is greater than the microstructure height 133H and equal to the spacer height 150H when all heights are measured from the same reference plane 132D. The difference in height between the microstructure height 133H, the reinforcement height 142H, and the spacer height 150H allows adjacent pieces of packing 130 to be spaced apart from each other sufficiently such that both the CO2 capture solution 114 and the CO2-containing air 101 can flow between adjacent pieces of packing 130 when the adjacent pieces of packing 130 are adhered together along their spacers 150 and their reinforcements 142. In some implementations, and referring to FIG. 1, the reinforcement height 142H is greater than the microstructure height 133H and equal to the spacer height 150H.Figure 4 Each of the stiffeners 142A has the same stiffener height 142H, each of the mass transfer microstructures 133 has the same microstructure height 133H, and each of the spacers 150 has the same spacer height 150H. In alternative embodiments, in any combination, the stiffeners 142A can have varying stiffener heights 142H, the mass transfer microstructures 133 can have varying microstructure heights 133H, and / or the spacers 150 can have varying spacer heights 150H.

[0195] In one possible embodiment of the intermediate reinforcing element 142, and with reference to Figure 4 , Figure 4 and Figure 5 , the intermediate stiffeners 142A making up the intermediate reinforcing element 142 are arranged in a first group 142C and a second group 142D of intermediate stiffeners 142A. The intermediate stiffeners 142A of the first group 142C are shown in dark gray shading in Figure 4 and extend outwardly from the first side 134A of the main body 132, as shown in Figure 4 . The intermediate stiffeners 142A of the second group 142D are shown in light gray shading in Figure 4 and extend outwardly from the second side 134B of the main body 132, as shown in Figure 4 . The intermediate stiffeners 142A of the first group 142C and the second group 142D are hollow bodies such that they form respective recesses on the other side of the main body 132 from which they extend. For example, and with reference to Figure 4A , the intermediate stiffeners 142A of the first group 142C extending outwardly from the first side 134A form a first group of recesses 144A on the second side 134B. Similarly, and with reference to Figure 4B and 4D , the intermediate stiffeners 142A of the second group 142D extending outwardly from the second side 134B form a second group of recesses 144B on the first side 134A. The first group of recesses 144A and the second group of recesses 144B are grooves or recesses extending into the main body 132 in a direction of extension transverse to the reference plane 132D. The first group of recesses 144A and the second group of recesses 144B have a height or dimension defined between the reference plane 132D on the side 134A, 134B of the main body 132 opposite the side 134B, 134A on which the attachment wall 142B of the corresponding intermediate stiffener 142A lies, and the attachment wall 142B. In Figure 4E the configuration of the intermediate reinforcing element 142, the first group of recesses 144A and the second group of recesses 144B alternate with each other in a direction parallel to the LTD 138L. In Figure 4On the first side 134A of the body 132 of the first embodiment, the middle stiffeners 142 of the first set 142C project outwardly on the first side 134A and adjacent recesses of the second set of recesses 144B exist on the second side 134B. Similarly, on the second side 134B of the body 132 of the first embodiment, the middle stiffeners 142 of the second set 142D project outwardly on the second side 134B and adjacent recesses of the first set of recesses 144A exist on the first side 134A. In the configuration of the middle stiffening elements 142 of the first embodiment, each stiffener 142A is adjacent to one or both of its negative pressure marks in the LTD 138L. In particular, on the first side 134A, the middle stiffeners 142 of the first set 142C alternate with the second set of recesses 144B along the axis 403. Similarly, on the second side 134B, the middle stiffeners 142 of the second set 142D alternate with the first set of recesses 144A along the axis 403. Figure 4 On the second side 134B of the body 132 of the second embodiment, the middle stiffeners 142 of the second set 142D project outwardly on the second side 134B and adjacent recesses of the first set of recesses 144A exist on the first side 134A. In the configuration of the middle stiffening elements 142 of the second embodiment, each stiffener 142A is adjacent to one or both of its negative pressure marks in the LTD 138L. In particular, on the first side 134A, the middle stiffeners 142 of the first set 142C alternate with the second set of recesses 144B along the axis 403. Similarly, on the second side 134B, the middle stiffeners 142 of the second set 142D alternate with the first set of recesses 144A along the axis 403. Figure 4A In the configuration of the middle stiffening elements 142 of the second embodiment, each stiffener 142A is adjacent to one or both of its negative pressure marks in the LTD 138L. In particular, on the first side 134A, the middle stiffeners 142 of the first set 142C alternate with the second set of recesses 144B along the axis 403. Similarly, on the second side 134B, the middle stiffeners 142 of the second set 142D alternate with the first set of recesses 144A along the axis 403.

[0196] The middle stiffeners 142A can have any suitable shape. For example, and with reference to Figure 4B and Figure 4E each middle stiffener 142A is a polygonal object defined by a plurality of planar walls 142P extending outwardly from one of the first side 134A and the second side 134B to an attachment wall 142B. With reference to Figure 4 each middle stiffener 142A can be shaped as a planar body with four planar walls 142P extending outwardly from one of the first side 134A and the second side 134B to an attachment wall 142B on the same side 134A, 134B. Figure 4A Each planar wall 142P in the second embodiment has a trapezoidal shape and is bounded by four edges. Other shapes of the planar walls 142P and other shapes of each middle stiffener 142A are possible. In the second embodiment, Figure 4A the middle stiffeners 142A of the middle stiffening elements 142 have the same shape and size. In other possible embodiments, the shape and / or size of the middle stiffeners 142A of the middle stiffening elements 142 can vary. For example, in one such other possible embodiment, the middle stiffeners 142A include one or more curved walls that form a sinusoidal shape in cross-sectional view, such as in the cross-sectional plane of Figure 4B the second embodiment.

[0197] With reference to Figure 4BEach intermediate stiffener 142A has one or more longitudinal flow channels 142F. Each longitudinal flow channel 142F is a groove or elongated depression that extends into each planar wall 142P. Each longitudinal flow channel 142F has an orientation that is parallel to the LTD 138L. Each longitudinal flow channel 142F helps to direct the flow of the CO2 capture solution 114 along the LTD 138L as the CO2 capture solution 114 flows along and / or between the intermediate stiffeners 142A. In Figure 4B In the embodiment of the intermediate stiffeners 142A of FIG. 6, each intermediate stiffener 142A has two longitudinal flow channels 142F on opposite sides of the attached wall 142B. In Figure 4B In the embodiment of the intermediate stiffeners 142A of FIG. 6, each intermediate stiffener 142A has two longitudinal flow channels 142F, and each longitudinal flow channel 142F is positioned laterally in the middle of its planar wall 142P. As the CO2 capture solution 114 flows along the packing sheet 130, it can enter each longitudinal flow channel 142F at its inlet and flow in a direction that is parallel to the LTD 138L to the outlet of the longitudinal flow channel 142F. In some embodiments, the CO2 capture solution 114 can flow through each longitudinal flow channel 142F in a direction that is substantially parallel to the vertical axis 135.

[0198] Each intermediate stiffener 142A can have fewer, more, or different configurations of flow directors for directing the flow of the CO2 capture solution 114 along the intermediate stiffener 142A. For example, and with reference to Figure 4B One or more of the intermediate stiffeners 142A have one or more lateral flow channels 142L. Each lateral flow channel 142L is for diverting or directing the CO2 capture solution 114 from the intermediate stiffener 142A in a direction that is transverse to the LTD 138L toward the mass transfer microstructure 133 that is adjacent to the intermediate stiffener 142A. Thus, each lateral flow channel 142L has an inlet end and an outlet end, where the inlet end is closer to the attached wall 142B than the outlet end (e.g., relative to a direction that is parallel to the ATD 138D). Each lateral flow channel 142L can have any shape, orientation, or arrangement on the intermediate stiffener 142A to accomplish this function. For example, and with reference to Figure 4D The lateral flow channel 142L extends along a common edge between two planar walls 142P from an inlet end adjacent to the attached wall 142B to an outlet end adjacent to the mass transfer microstructure 133. Figure 4The lateral flow channel 142L forms a non-zero angle with both LTD 138L and ATD 138D. In another possible embodiment of one or more lateral flow channels 142L, the lateral flow channel 142L extends along a planar wall 142P in a direction parallel to ATD 138D from the inlet end adjacent to the attachment wall 142B to the outlet end adjacent to the mass transfer microstructure 133. In another possible embodiment of one or more lateral flow channels 142L, and referring to... Figure 4 The inclined planar wall 142P on the opposite side of the attachment wall 142B in LTD 138L has multiple lateral flow channels 142LA. Figure 4A Each lateral flow channel 142LA forms a non-zero angle with both LTD 138L and ATD 138D. Lateral flow channel 1421a in... Figure 4 The intermediate reinforcements 142A intersect each other on the same plane wall 142P, forming an "X" shaped microstructure. The X shape formed by the lateral flow channel 1421a allows the packing sheet 130 to be oriented or inserted together with either the upper edge 136U or the lower edge 136L, while still retaining the function of the lateral flow channel 1421a.

[0199] Each lateral flow channel 142L, 142LA can help reduce or prevent channeling of the CO2 capture solution 114 as it flows along the intermediate stiffeners 142A, thereby helping to better distribute the CO2 capture solution 114 to the mass transfer microstructures 133 and improve the ability of the CO2 capture solution 114 to capture CO2 from the CO2-containing air 101. The CO2 capture solution 114 flowing in the LTD 138L can encounter a flow barrier at the joined attachment wall 142B of an adjacent packing sheet 130, and the lateral flow channels 142L, 142LA can help minimize channeling or streaming of the CO2 capture solution 114 in this location of the packing sheet 130 by helping to divert at least some of the CO2 capture solution 114 away from the joined attachment wall 142B and back to the mass transfer microstructures 133. Other features of the packing sheet 130 can have flow channels 142F, 142L. For example, in some embodiments, one or more flow channels 142F, 142L can be present in the stiffening ribs. The flow channels 142F, 142L, 142LA of the present disclosure form a groove or elongated depression on one of the first side 134A and the second side 134B of the packing sheet 130, and a corresponding ridge or protrusion on the other of the first side 134A and the second side 134B. In some embodiments, other features of the packing sheet 130 have flow channels 142F, 142L, 142LA of the present disclosure. For example, in one such embodiment, one or more spacers 150 have one or more flow channels 142F, 142L, 142LA to help divert at least some of the CO2 capture solution 114 away from the joined spacers 150 and back to the mass transfer microstructures 133.

[0200] The stiffening elements 140 can include other stiffeners. For example, and with reference to Figure 4A The stiffening elements 140 include one or more perimeter stiffeners 148. The perimeter stiffeners 148 can be present adjacent to each other along the LTD 138L to form a perimeter stiffening element. In some embodiments, and with reference to Figure 4 The perimeter stiffeners 148 are similar to the intermediate stiffeners 142A, such that the descriptions, features, and advantages of the present disclosure associated with the intermediate stiffeners 142A apply to the perimeter stiffeners 148 mutatis mutandis.

[0201] The perimeter stiffeners 148 reinforce or strengthen the body 132 along the perimeter portion, and can be used to attach adjacent packing sheets 130 together along the attachment walls of the perimeter stiffeners 148. Figure 4The peripheral reinforcement 148 defines some or all of the leading edge 136A and trailing edge 136B of the body 132. In an alternative embodiment, the peripheral reinforcement 148 defines some or all of one of the leading edge 136A and trailing edge 136B. In an alternative embodiment, the packing sheet 130 has no peripheral reinforcement 148 along its leading edge 136A and trailing edge 136B.

[0202] In some embodiments, the peripheral reinforcement 148 includes longitudinal and / or lateral flow channels 142F, 142L (such as... Figure 4 (Those shown). In some embodiments, packing sheets 130 are positioned adjacent to each other along packing depth 106D to form packing segments 106, and these packing sheets 130 are joined along their respective peripheral reinforcements 148. In such embodiments, the presence of longitudinal and / or lateral flow channels 142F, 142L in the peripheral reinforcements 148 can help reduce or eliminate CO2 trapping solution 114 reaching these interface points of the packing segment 106, where the CO2 trapping solution 114 can bypass the reactive surface areas of the packing segment 106 and is therefore less effective in trapping CO2 from the CO2-containing air 101. The presence of longitudinal and / or lateral flow channels 142F, 142L in the peripheral reinforcements 148 of these embodiments can also help reduce liquid pooling along the peripheral reinforcements 148 and / or along the interfaces, which can help reduce the pressure drop of the CO2-containing air 101 flowing along the packing depth 106D.

[0203] refer to Figure 4 The reinforcing element 140 includes one or more peripheral ribs 146. The peripheral ribs 146 are located on the body 132, adjacent to one or both of the leading edge 136A and trailing edge 136B. The peripheral ribs 146 are reinforcements that strengthen or reinforce the body 132 along the sides of the packing sheet 130. Figure 4 The packing sheet 130 has peripheral ribs 146 located adjacent to one or both of the leading edge 136A and the trailing edge 136B, at a distance from the respective leading edge 136A or trailing edge 136B. This distance may be less than one-third of ATD 138D. In an alternative embodiment, one or more of the peripheral ribs 146 are positioned inwardly from the leading edge 136A or trailing edge 136B on the body 132 and beyond this distance. Figure 4 The packing sheet 130 includes peripheral reinforcement 148 and peripheral ribs 146, and on the body 132 from the leading edge 136A and trailing edge 136B, the peripheral ribs 146 are positioned further inward than the peripheral reinforcement 148. (Reference) Figure 4The perimeter ribs 146 can be positioned adjacent to each other along the LTD 138L and can be positioned adjacent to each other along the ATD 138D, as described in more detail below. Each perimeter rib 146 is an elongated body that extends in a direction parallel to the LTD 138L. Referring to Figure 4 , Figure 4 and Figure 4 , each perimeter rib 146 has an arcuate or semi-circular cross-sectional shape, with the cross-sectional shape being defined in a plane transverse to the LTD 138L.

[0204] Referring to Figure 4 , each perimeter rib 146 has an orientation that is substantially parallel to the leading edge 136A. In some implementations, an axis extends through a plurality of perimeter ribs 146 that are aligned along the LTD 138L, and the axis is substantially parallel to the vertical axis 135. In some embodiments, the axis is substantially parallel to the leading edge 136A of the filler sheet 130.

[0205] Referring to Figure 4 , Figure 4 , Figure 4 and Figure 4 , each perimeter rib 146 extends outwardly from one of the first side 134A and the second side 134B. Each perimeter rib 146 extends outwardly to a local maximum that defines a surface of the perimeter rib 146 that is further from the plane of the body 132 than other portions of the perimeter rib 146. Each local maximum defines a surface of the perimeter rib 146 that is further from the mass transfer microstructure 133 than other portions of the perimeter rib 146. In the color scheme of Figure 4 , the darker gray shading on the perimeter ribs 146 represents the shaded portions extending outwardly from the body 132 on the first side 134A, and the lighter gray shading on the perimeter ribs 146 represents the shaded portions extending outwardly from the body 132 on the second side 134B.

[0206] The perimeter ribs 146 are hollow bodies, such that they form corresponding recesses on the other side of the body 132 from which the perimeter ribs extend. For example, and referring to Figure 4 and 4E , the perimeter ribs 146 that extend outwardly from the first side 134A form a first set of recesses 146A on the second side 134B. Similarly, and referring to Figure 4The perimeter ribs 146 extending outward from the second side 134B form a second set of depressions 146B on the first side 134A. The first set of depressions 146A and the second set of depressions 146B are grooves or recesses extending into the body 132 in a direction transverse to the extension of the reference plane 132D. The first set of depressions 146A and the second set of depressions 146B have a thickness or height defined between a local maximum of the corresponding perimeter rib 146 and the reference plane 132D on the side 134A, 134B of the body 132 opposite the side 134B, 134A on which the local maximum is located. Thus, each perimeter rib 146 forms a protrusion on the side 134A, 134B of the body 132 and a notch on the other side 134B, 134A.

[0207] Referring to Figure 4 Each perimeter rib 146 has a rib height 146H defined in a direction perpendicular to the reference plane 132D. The rib height 146H is measured relative to the reference plane 132D on the side 134A, 134B of the body 132 opposite the side 134A, 134B on which the local maximum of the perimeter rib 146 is located. For example, in Figure 4 the rib height 146H is measured relative to the reference plane 132D on the first side 134A of the body 132 because the local maximum of the perimeter rib 146 is on the second side 134B of the body 132. See Figure 6 The rib height 146H is greater than the microstructure height 133H when both heights are measured from the same reference plane 132D. Referring to Figure 6 The rib height 146H is less than the spacer height 150H when both heights are measured from the same reference plane 132D. Referring to Figure 6 and Figure 6 The rib height 146H is less than the reinforcement height 142H when both heights are measured from the same reference plane 132D. The height differences between the rib height 146H, the microstructure height 133H, the reinforcement height 142H, and the spacer height 150H allow adjacent filler pieces 130 to be spaced sufficiently apart from one another so that both the CO2capture solution 114 and the CO2-containing air 101 can flow between adjacent filler pieces 130 when the adjacent filler pieces 130 are adhered together along their spacers 150 and / or their reinforcements 142. The perimeter ribs 146 protrude into the flow of CO2-containing air 101 past the mass transfer microstructures 133.

[0208] The perimeter ribs 146 can be arranged on the filler piece 130 in any desired configuration to achieve the functions attributed to the perimeter ribs 146 in the present disclosure. For example, referring to Figure 6The perimeter ribs 146 include a plurality of leading edge ribs 146L that are located proximate the leading edge 136A of the body 132. The leading edge ribs 146L are arranged in two different groups of leading edge ribs 146L. The first group of leading edge ribs 146L includes innermost ribs 146L1 and the second group of leading edge ribs 146L includes outermost ribs 146L2. Along the ATD 138D, the outermost ribs 146L2 are spaced further from the leading edge 136A than the innermost ribs 146L1. The innermost ribs 146L1 are aligned with one another along the LTD 138L. The innermost ribs 146L1 have an orientation that is substantially parallel to the leading edge 136A. The outermost ribs 146L2 are aligned with one another along the LTD 138L. The outermost ribs 146L2 have an orientation that is substantially parallel to the leading edge 136A. Reference is made to Figure 7 and Figure 7 The innermost ribs 146L1 extend outwardly from the first side 134A of the body 132 and form respective depressions 146A in the second side 134B. Reference is made to Figure 7 and Figure 7A The outermost ribs 146L2 extend outwardly from the second side 134B of the body 132 and form respective depressions 146B in the first side 134A. In some embodiments, and reference is made to Figure 7A The innermost ribs 146L1 and the outermost ribs 146L2 are offset from one another in the LTD 138L. When Figure 7 The upper and lower ends of each of the innermost ribs 146L1 and the outermost ribs 146L2 are not aligned in the vertical direction when the packing sheet 130 is part of the structured packing 116 for a cross-flow configuration. When Figures 8 to 8C Some portions of the innermost / outermost ribs 146L1, 146L2 vertically overlap the upper and lower ends of the outermost / innermost ribs 146L2, 146L1 when the packing sheet 130 is part of the structured packing 116 for a cross-flow configuration.

[0209] Another possible configuration of the perimeter ribs 146 is shown in Figures 8 to 8C The perimeter ribs 146 include a plurality of trailing edge ribs 146T that are located proximate the trailing edge 136B of the body 132. The trailing edge ribs 146T are arranged in two different groups of trailing edge ribs 146T. The trailing edge ribs 146T include a third group of ribs 146T3 and a fourth group of ribs 146T4. Along the ATD 138D, the fourth group of ribs 146T4 is spaced further from the trailing edge 136B than the third group of ribs 146T3. The third group of ribs 146T3 are aligned with one another along the LTD 138L. The third group of ribs 146T3 have an orientation that is substantially parallel to the trailing edge 136B. The fourth group of ribs 146T4 are aligned with one another along the LTD 138L. The fourth group of ribs 146T4 have an orientation that is substantially parallel to the trailing edge 136B. Reference is made to Figures 8 to Figure 8BThe third set of ribs 146T3 (the rear edge rib 146T closest to the rear edge 136B) extends outward from the first side surface 134A of the main body 132 and forms a corresponding recess 146A in the second side surface 134B, as shown. Figures 8 to Figure 8C The fourth set of ribs 146T4 (the trailing edge rib 146T furthest from the trailing edge 136B) extends outward from the second side 134B of the body 132 and forms a corresponding recess 146B in the first side 134A, as shown. Figure 5 It is shown in a lighter gray shade. In some embodiments, and referenced... Figures 8A to 8B2 The third set of ribs 146T3 and the fourth set of ribs 146T4 are offset from each other in LTD 138L. When Figures 8 to Figure 8C When the packing sheet 130 is part of the structured packing 116 used in a crossflow structure, the upper and lower ends of each of the third group of ribs 146T3 and the fourth group of ribs 146T4 are not aligned in the vertical direction. Figure 8 When the packing sheet 130 is part of the structured packing 116 used in the crossflow structure, some portions of the third / fourth group ribs 146T3, 146T4 vertically overlap with the upper and lower ends of the fourth / third group ribs 146T4, 146T3.

[0210] The peripheral ribs 146 can be spaced apart to optimize the surface area of ​​the mass transfer region 131, which can be used to absorb CO2 into the CO2 trapping solution 114. For example, and referring to Figure 8 The peripheral rib 146 includes one or more longitudinal rib pairs 146C. The two peripheral ribs 146 in each longitudinal rib pair 146C are spaced apart from each other in a direction parallel to LTD 138L. A longitudinal mating gap 146G1 is defined between the two peripheral ribs 146 in each longitudinal rib pair 146C. (Reference) Figure 8 The mass transfer microstructure 133 exists within the longitudinal mating gap 146G1. For simplicity, the mass transfer microstructure 133 in the longitudinal mating gap 146G1 is only relative to... Figure 8 As shown in the third set of ribs 146T3, it should be understood that the packing sheet 130 may have multiple longitudinally paired gaps 146G1. Figure 8 The peripheral ribs 146 of the packing sheet 130 are discontinuous on the liquid travel dimension LTD138L. Figure 8 The peripheral ribs 146 of the packing sheet 130 are spaced apart in the liquid travel dimension LTD 138L by mass transfer microstructures 133. The longitudinal mating gap 146G1 is... Figure 8 The packing sheets 130 have the same dimensions. In an alternative embodiment, the longitudinal mating gap 146G1 is in Figure 8 The same packing sheet 130 has different sizes.

[0211] The perimeter ribs 146 can also be spaced apart in a direction parallel to the ATD 138D to optimize the surface area of the mass transfer zone 131 that is available for absorbing CO2 into the CO2 capture solution 114. For example, and with reference to Figure 8 , the perimeter ribs 146 include one or more pairs of lateral ribs 146D. The two perimeter ribs 146 in each pair of lateral ribs 146D are spaced apart from each other in a direction parallel to the ATD 138D. A lateral pair gap 146G2 is defined between the two perimeter ribs 146 in each pair of lateral ribs 146D. With reference to Figure 8 , the mass transfer microstructure 133 is present in the lateral pair gap 146G2. For simplicity, the mass transfer microstructure 133 in the lateral pair gap 146G2 is only shown in Figures 8A to 8C for two trailing edge ribs 146T, it will be appreciated that the packing sheet 130 can have multiple lateral pair gaps 146G2. The lateral pair gap 146G2 has a longitudinal extent defined along the LTD 138L. In Figure 8A , the same mass transfer microstructure 133 is present in both the longitudinal pair gap 146Gl and the lateral pair gap 146G2. In alternative embodiments, the mass transfer microstructure 133 can be different in the longitudinal pair gap 146Gl and the lateral pair gap 146G2. In some embodiments, the mass transfer microstructure 133 can be different between longitudinal pair gaps 146Gl of the same packing sheet 130 or between lateral pair gaps 146G2 of the same packing sheet 130.

[0212] Figure 8Another possible implementation of a filler sheet 630 is shown in FIG. 6. The reinforcing elements 640 of the filler sheet 630 include intermediate ribs 646. The intermediate ribs 646 are located on the main body 632 between the leading edge 636A and the trailing edge 636B. The intermediate ribs 646 are located midway along the main body 632 between the leading edge 636A and the trailing edge 636B at a position that is one-half of the ATD 138D from the leading edge 636A. On either side of the intermediate ribs 646 in the ATD 138D, the intermediate ribs 646 are located midway along the main body 632 between the spaced portions 150. A first set of intermediate ribs 646A are spaced apart from one another and aligned in a direction parallel to the LTD 138L. A second set of intermediate ribs 646B are also spaced apart from one another and aligned in a direction parallel to the LTD 138L. The second set of intermediate ribs 646B are spaced apart from the first set of intermediate ribs 646A in a direction parallel to the ATD 138D. Mass transfer microstructures 133 are present in the spaces between the intermediate ribs 646. The first set of intermediate ribs 646A extend outwardly from the first side face 634A of the main body 632 and form corresponding recesses in the second side face 634B. The second set of intermediate ribs 646B extend outwardly from the second side face 634B and form corresponding recesses in the first side face 634A. These protrusions and recesses of the intermediate ribs 646 are used to align the filler sheet 630 with the other components of the heat spreader 130. The filler sheet 630 is shown in FIG. 6 with a gray-shaded color scheme. Figure 8A

[0213] When Figure 8A1 ​When the packing sheet 630 is part of a structured packing 116 for a crossflow configuration, portions of the first and second sets of intermediate ribs 646A, 646B vertically overlap. Each intermediate rib 646 in the first set of intermediate ribs 646A has a first rib end 647A and a second rib end 647B, the second rib end 647B spaced apart from the first rib end 647A in a direction parallel to the LTD 138L. The first rib end 647A is closer to the upper edge 636U of the main body 632 than the second rib end 647B. Each intermediate rib 646 in the second set of intermediate ribs 646B has a third rib end 647C and a fourth rib end 647D, the fourth rib end 647D spaced apart from the third rib end 647C in a direction parallel to the LTD 138L. The third rib end 647C is closer to the upper edge 636U of the main body 632 than the fourth rib end 647D. The third rib end 647C of one or more ribs in the second set of ribs 646B is positioned vertically between the first rib end 647A and the second rib end 647B of one rib in the first set of ribs 646A. The fourth rib end 647D of one or more ribs in the second set of ribs 646B is positioned vertically between the first rib end 647A and the second rib end 647B of one rib in the first set of ribs 646A. In at least some embodiments, the intermediate ribs 646 are reinforcing elements 640 that overlap at a middle of a depth of the packing sheet 630, which can help to reinforce or strengthen the packing sheet 630 against loads. The description, features, and advantages of the present disclosure associated with the packing sheet 130 of the preceding figures apply mutatis mutandis to the packing sheet 630 Figure 8A of the packing sheet 630. For example, a height of the intermediate ribs 646, measured similarly to the heights 133H, 142H, 150H described above, can be less than a height of the perimeter reinforcement 148. The description, features, and advantages of the present disclosure associated with the perimeter ribs 146 apply mutatis mutandis to the intermediate ribs 646 Figure 8A of the packing sheet 630. For example, a height of the intermediate ribs 646, measured similarly to the heights 133H, 142H, 150H described above, can be less than a height of the perimeter reinforcement 148. The description, features, and advantages of the present disclosure associated with the perimeter ribs 146 apply mutatis mutandis to the intermediate ribs 646

[0214] The spacing 150 and reinforcing elements 140, 640 of the packing sheet 130, 630 described above and shown in the figures can be present or absent in any combination to provide any desired configuration of the packing sheet 130, 630, structured packing 116, and / or packing section 106.

[0215] Figure 8B Another possible configuration of a packing sheet with approximately zero degree offset angle D is shown in 7A Another possible configuration of a packing sheet with approximately zero degree offset angle D is shown in Figure 8 Another possible configuration of a packing sheet with approximately zero degree offset angle D is shown in 7A The packing sheet 730 includes one or more reinforcing elements 740. Unlike the reinforcing elements 140, 640 described previously, which protrude from a surface of the main body 132, 632 of the packing sheet 130, 630, the reinforcing elements 740 of the packing sheet 730 form the main body 732 itself. Reference is made to Figure 8B andFigure 8B1 Each reinforcing element 740 is a local deviation from a plane defined by the remaining portion of the body 732 that does not include the reinforcing element 740. The out-of-plane reinforcing elements 740 provide a wavy or sinusoidal shape to the packing sheet 730 in cross-sectional view. Figure 8C The mass transfer zone 131 and the mass transfer microstructure 133 along all or some extent of the reinforcing element 740 such that the reinforcing element 740 defines a portion of the reactive surface area of the packing sheet 730 that contributes to the capture of CO2 from the CO2-containing air 101. The reinforcing element 740 contributes to the reinforcement or reinforcement body 732 to resist expected loads on the packing sheet 730. By forming the body 732 of the packing sheet 730, the reinforcing element 740 contributes to the reinforcement of the packing sheet 730 while having minimal, if any, impact on the pressure drop of the CO2-containing air 101 flowing through the structured packing 116 formed by the packing sheet 730. In some embodiments, the packing sheet 730 can be further reinforced by the material of construction (MOC) of the packing sheet 730. The descriptions, features, and advantages of the present disclosure associated with the packing sheets 130, 630 of the preceding figures apply to the packing sheet 730 of Figure 8A with necessary modifications.

[0216] Figure 8C Another possible configuration of a packing sheet with an approximate zero degree offset angle delta is shown in Figure 8C The packing sheet 830 includes a reinforcement 842. The reinforcement 842 is another embodiment of the reinforcing element 140, 640 of the present disclosure and can be present on the packing sheet 130, 630, 730, 830 in any combination with the reinforcing element 140, 640 of the present disclosure. The reinforcement 842 extends outwardly from a first side 834A and a second side 834B of the packing sheet 830. In Figures 8 to 8C In the color scheme of Figure 8A The reinforcement 842 of Figure 8A2 forms a structure similar to the structure of the intermediate reinforcement 142A of Figure 8B ). The descriptions, features, reference characters, and advantages of the present disclosure associated with the intermediate reinforcement 142A apply to the reinforcement 842 of Figure 8B2reinforcements 842. For example, similar to the intermediate reinforcement 142A, the reinforcement 842 is hollow and forms a corresponding recess on the other side (e.g., opposite side) of the main body 832 from which the reinforcement 842 extends. In Figure 8C In the configuration of the reinforcement 842, the recesses and extensions on one side of the main body 832 alternate with each other in a direction parallel to the ATD 138D. In alternative embodiments, the reinforcement 842 has a different shape, geometry, and / or configuration than the intermediate reinforcement 142A.

[0217] Each reinforcement 842 is an elongated body having a main dimension defined parallel to the ATD 138D. Each reinforcement 842 has a width defined parallel to the ATD 138D that is longer than a length of the reinforcement defined parallel to the LTD 138L. The reinforcements 842 are positioned adjacent to each other along the ATD 138D. The reinforcements 842 are positioned between the leading edge 836A and the trailing edge 836B of the filler sheet 830 to form a row of reinforcements 842 parallel to the ATD 138D. The reinforcements 842 help reinforce the filler sheet 830 by supporting the filler sheet 830 against lateral or bending loads caused by the weight of the filler sheet 830 itself or other filler sheets 830 in combination therewith, liquid holdup of the CO2capture solution 114 on the filler sheet 830, any fouling present on the filler sheet 830, and / or other loads. As described in more detail below, when two filler sheets 830 are attached together, some portions of the reinforcements 842 join to corresponding portions of the reinforcements 842 of the adjacent filler sheet 830, which can help reinforce the joined filler sheets 830 and help prevent them from collapsing toward each other in areas of the filler sheet 830 where there is a relatively large distance between the joined supports. Thus, the reinforcements 842 can be any structure that can support the loads described herein. The reinforcements 842 can have any arrangement, number, position, form, shape, or size to achieve the functions attributed to them herein. In some embodiments, and with reference to Figure 8A The reinforcements 842 are disposed on or adjacent to the mass transfer zone 831 and its mass transfer microstructure 133. With reference to Figure 8A2 The reinforcements 842 form a continuous or uninterrupted row of reinforcements 842 that extends completely between the leading edge 836A and the trailing edge 836B. In alternative embodiments, the reinforcements 842 form a discontinuous or interrupted row of reinforcements 842 between the leading edge 836A and the trailing edge 836B. In some embodiments, and with reference to Figure 8A2 The reinforcements 842 are free of the mass transfer microstructure 133.

[0218] The reinforcements 842 can be present in any arrangement along the filler sheet 830. For example, with reference to Figure 8A2The reinforcement 842 includes intermediate reinforcements 842M forming an intermediate row 844M, and edge reinforcements 842E forming an upper row 844U and a lower row 844L. The intermediate row 844M, the upper row 844U, and the lower row 844L are different arrangements of the reinforcement 842 and are separated from one another along the LTD 138L. The edge reinforcements 842E of the upper row 844U define some or all of the upper edge 836U. The edge reinforcements 842E of the lower row 844L define some or all of the lower edge 836L. The horizontally extending upper row 844U and lower row 844L assist in maintaining the stability of the mat 830 along the upper edge 836U and the lower edge 836L of the mat 830 when adjacent mat pieces 830 are joined together along the edge reinforcements 842E of the upper row 844U and the lower row 844L. The horizontal honeycomb features at the top and bottom of the mat piece 830 can assist in providing a more stable upper edge 836U and lower edge 836L of the conforming mat 116 formed by the joined mat pieces 830 in its installed configuration, and can assist in better transferring the load of the bottom support into the mat pieces 830 of the conforming mat 116.

[0219] The intermediate reinforcements 842M of the intermediate row 844M are disposed between the upper edge 836U and the lower edge 836L of the mat piece 830. In some embodiments, and with reference to Figure 8B , the intermediate reinforcements 842M of the intermediate row 844M extend through a vertical middle position of the mat piece 830, where the vertical middle position is defined as half the distance between the upper edge 836U and the lower edge 836L. In some embodiments, and with reference to Figure 8B2 , the intermediate reinforcements 842M of the intermediate row 844M extend through the center of mass 132C of the mat piece 830. In some embodiments, the intermediate reinforcements 842M of the intermediate row 844M are offset from the vertical middle position and positioned between the upper edge 836U and the lower edge 836L. In some embodiments, the mat piece 830 includes a plurality of intermediate reinforcements 842M of the intermediate row 844M extending parallel to the ATD 138D and between the upper edge 836U and the lower edge 836L. The intermediate reinforcements 842M of the intermediate row 844M each have a length that is greater than the length of each of the edge reinforcements 842E of both the upper row 844U and the lower row 844L, where the lengths of the intermediate reinforcements 842M and the edge reinforcements 842E are parallel to the LTD 138L. In some embodiments, the length of the intermediate reinforcements 842M is twice the length of the edge reinforcements 842E. In some embodiments, removing a vertical half of one of the intermediate reinforcements 842M provides a shape that corresponds to the shape of one of the edge reinforcements 842E. The shape similarity between the intermediate reinforcements 842M and the edge reinforcements 842E can be caused by an indexing interval of a tool used to form the mat piece 830. In some embodiments, and with reference to Figure 8CThe packing sheet 830 has an intermediate reinforcement 842M in the intermediate row 844M and edge reinforcements 842E in the upper row 844U and lower row 844L. In an alternative embodiment, the packing sheet 830 does not have the intermediate reinforcement 842M in the intermediate row 844M, but still includes the edge reinforcement 842E in the upper row 844U and lower row 844L. In an alternative embodiment, the packing sheet 830 does not have the intermediate reinforcement 842M in the intermediate row 844M, but still includes the edge reinforcement 842E in one of the upper row 844U and lower row 844L.

[0220] The packing sheet 830 can be cut or segmented through the vertical midpoint of the intermediate reinforcement 842M of the intermediate row 844M to form a packing sheet 830 of the desired size, which can be perpendicularly aligned with the upper edge 836U or lower edge 836L of the adjacent packing sheet 830 (e.g., one packing sheet 830 is stacked on top of another along their adjacent edges 836U, 836L). Figures 8 to 8C In an exemplary embodiment where the packing sheet 830 has a length of 4 feet measured from a horizontal reference in a direction parallel to LTD 138L, and the intermediate row 844M has a length of feet measured from a horizontal reference, the packing sheet 830 can be cut along the intermediate row 844M to produce two packing sheets 830, each packing sheet 830 having a length of feet. The intermediate reinforcement 842M that divides the intermediate row 844M forms the upper row 844U or lower row 844L of the edge reinforcement 842E, such that the resulting two packing sheets 830 do not have the intermediate reinforcement 842M of the intermediate row 844M. Each of the two 2-foot packing sheets 830 can be attached along the attachment wall 842B of the edge reinforcement 842E to a packing sheet 830 of similar size to form a 2-foot long structured packing 116. Thus, in some embodiments, the packing sheet is Figures 9 The 830 is a segmented version of the packing sheet, and the 842M is a middle reinforcement without the middle row 844M.

[0221] In addition to their structural functions, the reinforcements 842 arranged across ATD 138D can also help redistribute some of the CO2 trapping solution 114 flowing along the packing strips 830 in LTD 138L or between adjacent packing strips 830 along LTD 138L (or may have features that contribute to the above effects). The reinforcements 842 can help intercept and disrupt flows or trickles of CO2 trapping solution 114 that may form in LTD 138L, thereby helping to prevent the formation of such trickles, prevent such trickles from traveling along the packing strips 830, or prevent such trickles from flowing between perpendicularly adjacent packing strips 830. The reinforcements 842 can help disperse the CO2 trapping solution 114 into the mass transfer zone 831 and its mass transfer microstructure 133.

[0222] Reference is now made to Figure 9 Some features of the reinforcement 842 that can interfere with or divert the fine stream of CO2 capture solution 114 are described in more detail. For example, Figure 10 An enlarged view of one of the intermediate reinforcement bodies 842M in region VIIIA in Figure 10 is shown. Referring to Figure 11 and Figure 12 , the intermediate reinforcement body 842M has one or more lateral flow channels 842L. Each lateral flow channel 842L is used to divert or direct CO2 capture solution 114 in a direction that is transverse to the LTD 138L and away from the attachment wall 842B. Thus, each lateral flow channel 842L has an inlet end and an outlet end, with the inlet end (e.g., relative to a direction parallel to the ATD 138D) closer to the attachment wall 842B than the outlet end. Each lateral flow channel 842L can have any shape, orientation, or arrangement on the intermediate reinforcement body 842M to achieve this functionality. For example, and referring to Figure 12 , the lateral flow channels 842L extend on some planar walls 842P of the intermediate reinforcement body 842M in a direction parallel to the ATD 138D. Referring to Figure 12 Two planar walls 842P of the intermediate reinforcement body 842M that are separated from each other in the ATD 138D by the attachment wall 842B have lateral flow channels 842L. Each of these planar walls 842P has two lateral flow channels 842L that are spaced apart from each other in the LTD 138L. Two other planar walls 842P of the intermediate reinforcement body 842M have no lateral flow channels 842L.

[0223] Figure 12 An enlarged view of one of the edge reinforcement bodies 842E in region VIIIB in Figure 12 is shown. Referring to Figure 12 , Figure 12 and ​ , two planar walls 842P of the edge reinforcement body 842E that are separated from each other in the ATD 138D by the attachment wall 842B have lateral flow channels 842L. Each of these planar walls 842P has one lateral flow channel 842L. Two other planar walls 842P of the edge reinforcement body 842E have no lateral flow channels 842L. In some embodiments, there are more than two flow channels 842L on the planar walls 842P that have flow channels 842L.

[0224] Referring to ​ , 8A1Each lateral flow channel 842L extends into its planar wall 842P, forming a recess on one side of the body 832 of the packing piece 830 (e.g., on the first side 834A) and a protrusion on the other side of the body 832 (e.g., on the second side 834B). Referring to FIGS. 8B, 8B1, and 8C, each lateral flow channel 842L extends into its planar wall 842P, forming a recess on one side of the body 832 of the packing piece 830 (e.g., on the first side 834A) and a protrusion on the other side of the body 832 (e.g., on the second side 834B). Referring to ​ , each lateral flow channel 842L extends between the attached walls 842B (see ​ ) of laterally adjacent stiffeners 842. In some embodiments, the height or thickness of the lateral flow channel 842L is measured in a direction normal to the plane of the respective planar wall 842P. CO2 capture solution 114 flowing in the LTD 138L can encounter a flow obstruction at the joined attached walls 842B of adjacent packing pieces 830, and the lateral flow channel 842L can help to minimize the channeling, streaming, and / or flow of CO2 capture solution 114 in that location by diverting at least some of the CO2 capture solution 114 away from the joined attached walls 842B and along the inclined planar wall 842P. The descriptions, features, and advantages of the present disclosure associated with the lateral flow channels 142L, 142LA of the preceding figures apply to the lateral flow channels 842L of ​ , mutatis mutandis.

[0225] One or both of the intermediate stiffener 842M and the edge stiffener 842E can include other features to help divert the flow of CO2 capture solution 114 around the joined attached walls 842B of adjacent packing pieces 830. For example, and referring to ​ , ​ , ​ , ​ , and ​ , one or more of the planar walls 842P can include a step member 850. The step member 850 can form a discontinuous and segmented rib along the edge of the mass transfer zone 831 to help direct the flow of CO2 capture solution 114 around the joined attached walls 842B and minimize the streaming of CO2 capture solution 114. Referring to ​ , and ​The two planar walls 842P of the intermediate stiffener 842M have a stepped member 850 that separates them from one another in the LTD 138L by the attached wall 842B. Each of these planar walls 842P has one step feature 850. The other two planar walls 842P of the intermediate stiffener 842M do not have a stepped member 850. The stepped member 850 includes a plurality of sloped segments. The stepped member 850 includes a first wall segment 852 that extends from the attached wall 842B and has a first slope that is different from the slope of the attached wall. The stepped member 850 includes a second wall segment 854 that extends from the first wall segment 852 and has a second slope that is different from the first slope of the first wall segment 852. The stepped member 850 includes a third wall segment 856 that extends from the second wall segment 854 and has a third slope that is different from the second slope of the second wall segment 854. The attached slope and the first, second, and third slopes are defined in the same cross-sectional plane and are shown in ​ FIG. 8. ​ In embodiments of the stepped member 850 of the edge stiffener 842E, the second slope of the second wall segment 854 is less than both the first and third slopes, and greater than the slope of the attached wall 842B. In another embodiment, one or more of the first, second, and third wall segments 852, 854, and 856 have a curved form. ​ , ​ and ​ The stepped member 850 of the edge stiffener 842E is similarly described, mutatis mutandis. In some embodiments, and with reference to ​ the intermediate stiffener 842M and / or the edge stiffener 842E includes both the stepped member 850 and at least one lateral flow channel 842L to facilitate turning the flow of the CO2 capture solution 114 around the joined attached wall 842B of an adjacent packing sheet 830. In another embodiment, the intermediate stiffener 842M and / or the edge stiffener 842E includes one of the stepped member 850 and at least one lateral flow channel 842L to facilitate turning the flow of the CO2 capture solution 114 around the joined attached wall 842B.

[0226] The descriptions, features, and advantages of the present disclosure associated with the packing sheets 130, 630, 730 of the preceding figures apply, mutatis mutandis, to the packing sheet 830. ​

[0227] ​ ​is a perspective view of a recessed body 960 of a filler sheet 130, 630, 730, 830 of the present disclosure. The recessed body 960 is an elongated body having a major dimension defined parallel to the LTD 138L. The recessed body 960 has a length defined substantially parallel to the LTD 138L that is longer than a width defined parallel to the ATD 138D. The recessed body 960 is located below one of the edge stiffeners 842E in the lateral middle of the filler sheet 130, 630, 730, 830, proximate to the upper edge 136U, 636U, 836U of the filler sheet 130, 630, 730, 830. The recessed body 960 can assist in forming the filler sheet 130, 630, 730, 830, for example, by assisting in indexing when using a forming tool such as a punch die. The recessed body 960 has a height that is greater than the microstructure height 133H and less than the spacer height 150H. The recessed body 960 has a height that is less than the stiffener height 142H. The heights of the recessed body 960, the microstructure height 133H, the spacer height 150H, and the stiffener height 142H described herein are measured from the same datum. When two filler sheets 130, 630, 730, 830 are joined to each other and define an airflow passage or channel between the pair of joined filler sheets 130, 630, 730, 830, the recessed bodies 960 of the two filler sheets 130, 630, 730, 830 are spaced apart from each other and bound a portion of the airflow passage or channel. In some embodiments, and with reference to ​ , the recessed body 960 is free of mass transfer microstructures 133. In some embodiments, the recessed body 960 has a smooth, flat surface.

[0228] The filler sheets 130, 630, 730, 830 can be arranged to form a shaped filler 116 having any shape, such as a block, a column, a cube, or other suitable shape. Each shaped filler 116 can sometimes be referred to as a “fill pack.” In some embodiments, and with reference to ​ , the filler sheets 130, 630, 730, 830 (hereinafter referred to simply as “filler sheets 130” or “a plurality of filler sheets 130”) are attached together to form a self-supporting shaped filler 116 such that the shaped filler 116 has the ability to remain upright and assembled without being supported by something else. One or more filler sheets 130 in each shaped filler 116 can be mounted to or supported by one or both of: 1) a structural member 115 of the housing 102, and 2) at least one other filler sheet 130 of another shaped filler 116. In some embodiments, and with reference to ​In the structured packing 116, all of the packing pieces 130 are identical. In alternative embodiments, one or more packing pieces 130 of the structured packing 116 differ from another packing piece 130 of the structured packing 116. In one example of such an alternative embodiment of the structured packing 116, one or more packing pieces 130 are free of the strengthening elements 140, 640, 740 and are optimized for minimum pressure drop, while another packing piece 130 has one or more strengthening elements 140, 640, 740 to strengthen the structured packing 116. The assembly of the packing pieces 130 into the structured packing 116 facilitates the structured packing 116 meeting load requirements, such as crush strength requirements, where the structured packing 116 is exposed to a crush test, the purpose of which is to simulate different loads (e.g., liquid load, liquid holdup, fouling / scaling, the weight of the structured packing 116 itself) to which the structured packing 116 can be exposed during operation of the gas-liquid contactor 100, 100A, 100B.

[0229] Referring to ​ , the leading edge 136A of the packing piece 130 is substantially parallel to the vertical axis 135, thereby providing the structured packing 116 with the additional leading edge surface area 139 described above and the associated benefits. ​ Attached packing pieces 130 are shown adjacent to one another and spaced apart from one another in a direction perpendicular to the ATD 138D and the LTD 138L. Adjacent packing pieces 130 are attached along their abutment surfaces 152 of their spacing portions 150. Adjacent packing pieces 130 can also be attached together using other features, such as one or more strengthening elements 140, 640. For example, referring to ​ , the middle strengthening bodies 142A of one or more packing pieces 130 are attached to the middle strengthening bodies 142A of other packing pieces 130 by their abutment attachment walls 142B. In ​ , the attachment wall 142B on the first side face 134A of a packing piece 130 abuts against the attachment wall 142B on the second side face 134B of an adjacent packing piece 130. These features space the adjacent packing pieces 130 apart such that a gas flow passage 160 or channel is defined between a pair of adjacent packing pieces 130. Thus, the gas flow passages 160 can be defined by the points of contact between adjacent packing pieces 130. Each gas flow passage 160 is bounded by the surfaces and features of adjacent packing pieces 130 and defines a space that extends in the ATD 138D and the LTD 138L. The CO2-containing air 101 flows through each gas flow passage 160 from the leading edge 136A to the trailing edge 136B of adjacent packing pieces 130. Referring to ​Each gas flow channel 160 is continuous or uninterrupted along the ATD 138D and along the LTD 138L from the leading edge 136A to the trailing edge 136B of an adjacent packing sheet 130. In some embodiments, one or more of the gas flow channels 160 has a channel shape 160S. The channel shape 160S is defined in a plane perpendicular to the LTD 138L. In some embodiments, the channel shape 160S is rectangular along the entire extent of the gas flow channel 160, as shown by the gray shading in ​ In some embodiments, and with reference to ​ The structured packing 116 is composed of planar or straight packing sheets 130. In some embodiments, and with reference to ​ The structured packing 116 has no undulations in its packing sheets 130 and no undulating channel shapes 160S between its packing sheets 130.

[0230] With reference to Figure 12 A sheet spacing 160H of the packing sheets 130 of the structured packing 116 can be defined. The sheet spacing 160H also defines the“width” or extent of each gas flow channel 160. The sheet spacing 160H is defined as the extent between a pair of adjacent packing sheets 130 and is measured in a plane perpendicular to the LTD 138L. The sheet spacing 160H can vary along the ATD 138B and along the LTD 138L due to the presence of features of adjacent packing sheets 130 (e.g., the stiffening elements 140 and the spacers 150). In some embodiments, the sheet spacing 160H is defined along a portion of the ATD 138B and / or the LTD 138L between mass transfer microstructures 133 of adjacent packing sheets 130. In some embodiments, the sheet spacing 160H is greater than each of the microstructure height 133H, the spacer height 150H, and the stiffener height 142H of one of the pair of packing sheets 130 that bound the gas flow channel 160. In some embodiments, and with reference to Figure 12 The sheet spacing 160H is substantially uniform between all pairs of adjacent packing sheets 130 that make up the structured packing 116. In alternative embodiments, the sheet spacing 160H between a first pair of packing sheets 130 of the structured packing 116 can be different than the sheet spacing 160H between at least another pair of packing sheets 130 of the same structured packing 116. Some possible and non-limiting examples of dimensions of the sheet spacing 160H include 5 / 8 inch (1.587 cm) to 1.5 inches (3.81 cm). The number of packing sheets 130 within each structured packing 116 and their sheet spacing 160H within the structured packing 116 can vary to provide structured packings 116 with desired sheet densities and performance characteristics.

[0231] When a pair of adjacent packing pieces 130 are attached along their mid-stiffener 142A attachment walls 142B to form a joint, the joint can impede the flow of CO2 capture solution 114 in the LTD 138L. Accordingly, the planar walls 142P of the mid-stiffeners 142A can have one or more flow channels, such as the longitudinal or lateral flow channels 142F, 142L described above. The flow channels can extend from the joined attachment walls 142B and help to reduce liquid pooling along the joint between adjacent packing pieces 130. The description, features, and advantages of the present disclosure associated with the longitudinal or lateral flow channels 142F, 142L of the perimeter stiffeners 148 apply mutatis mutandis to the flow channels of the mid-stiffeners 142A.

[0232] The gas flow channels 160 can extend around some of the planar walls 142P and attachment walls 142B of the mid-stiffeners 142A. A first group 142C of mid-stiffeners 142A extends outward from the first side 134A of the main body 132, and thus forms a corresponding recess 144A on the second side 134B. A second group 142D of mid-stiffeners 142A extends outward from the second side 134B of the main body 132, and thus forms a corresponding recess 144B on the first side 134A. The recesses 144A, 144B of the attached packing pieces 130 face each other across the piece spacing 160H, and are aligned along the LTD 138L. The gas flow channels 160 extend through the space between the facing recesses 144A, 144B of a pair of attached packing pieces 130, and are partially defined by that space. The gas flow channels 160 meander around the attached attachment walls 142B of the mid-stiffeners 142A.

[0233] The perimeter stiffeners 148 can similarly contribute to the size, shape, and configuration of the gas flow channels 160. For example, with reference to Figure 11The perimeter stiffeners 148 of each packing sheet 130 extend outwardly from one of the first and second sides 134A, 134B and form a respective recess 148D in the other of the first and second sides 134A, 134B. In some embodiments, a first set of perimeter stiffeners 148 alternate with a second set of recesses along an axis on the first side 134A, and a second set of perimeter stiffeners 148 alternate with the first set of recesses along the axis on the second side 134B. Adjacent packing sheets 130 are joined along the connecting walls of their perimeter stiffeners 148, with the attachment walls on the first side 134A of one packing sheet 130 connected to the attachment walls on the second side 134B of an adjacent packing sheet 130. Perimeter stiffener flow passages 148F are formed between the aligned recesses 148D of adjacent packing sheets 130. The perimeter stiffener flow passages 148F are in fluid communication with the gas flow channels 160, such that the C02-containing air 101 enters the structured packing 116 first via the perimeter stiffener flow passages 148F and then flows through the gas flow channels 160. The perimeter stiffener flow passages 148F can be defined or bounded by the abutting perimeter stiffeners 148. In some embodiments, adjacent packing sheets 130 are joined only along their perimeter stiffeners 148.

[0234] When adjacent packing sheets 130 are joined along their intermediate stiffeners 142A and / or the attachment walls 142B of their perimeter stiffeners 148, the joined stiffeners 142A, 148 form a honeycomb or hexagonal shape when the adjacent packing sheets 130 are viewed from one of the edges 136A, 136B, 136L, 136U, as shown in Figures 10 to 12 In other embodiments of joined stiffeners 142A, 148, in which the joined stiffeners 142A, 148 have one or more curved walls that form a sinusoidal shape in cross-section, the stiffeners 142A, 148 can be joined along the attachment points of the curved facets, such that the joined stiffeners 142A, 148 form a non-planar shape when the adjacent packing sheets 130 are viewed from one of the edges 136A, 136B, 136L, 136U. In one possible embodiment of stiffeners 142A, 148 having one or more curved walls that form a sinusoidal shape, the stiffeners 142A, 148 can be joined along some or all of the extent of the curved walls. Figures 10 to 12 The stiffeners 142A, 148 are joined such that their "peaks" (e.g., their attachment walls 142B) are aligned with the peaks of the adjacent packing sheet 130. In other possible embodiments, the stiffeners 142A, 148 are joined such that their maxima and minima are misaligned with the maxima and minima of the adjacent packing sheet 130. This paragraph applies mutatis mutandis to the stiffeners 842. Figures 8 to 8C The stiffeners 842.

[0235] The features of the packing sheets 130, 630, 730, 830 can allow for improved mass transfer capture efficiency. The features of the packing sheets 130, 630, 730, 830 can reduce the pressure drop experienced by the C02-containing air 101 flowing through the packing sheets 130, 630, 730, 830. For a given pressure drop tolerance across the packing section 106, the features of the packing sheets 130, 630, 730, 830 can allow for improved overall performance such that the ATD 138D can be reduced, which can allow for one or more of the following advantages: a shorter gas-liquid contactor 100, 100A, 100B with reduced pumping requirements of the C02 capture solution 114, a smaller footprint of the gas-liquid contactor 100, 100A, 100B, lower energy requirements for operating the fan 212, and / or the addition of additional drift elimination (if needed) without significant pressure drop penalty.

[0236] Any of the packing sheet 130, 630, 730, 830 features described herein or shown in the drawings can be present or absent in any combination to provide any desired configuration of the packing sheet 130, 630, 730, 830, structured packing 116, and / or packing section 106. For example, the packing sheet 130, 630, 730, 830 can be free of the strengthening element 140, 640, 740, 842 at the middle of the packing sheet 130, 630, 730, 830 along the ATD 138D. According to another example, the features that help divert or disperse the C02 capture solution 114 to the mass transfer microstructure 133 can be present or absent on one or more of the strengthening elements 140, 640, 740, 842 in any combination.

[0237] Reference Figure 15 According to one possible and non-limiting example for the gas-liquid contactor 100, 100A, 100B, the gas-liquid contactor 100, 100A, 100B having the structured packing 116 and its packing sheets 130, 630, 730, 830 disclosed herein is part of a direct air capture (DAC) system 1200 for capturing C02 directly from atmospheric air. One or more gas-liquid contactors 100, 100A, 100B use the C02 capture solution 114 to absorb some C02 from the C02-containing air 101 to form a C02-containing capture solution 111. The C02 capture solution 114 can need to be regenerated from the C02-containing capture solution 111, which can be done in a regeneration system 1230 of the DAC system 1200. The regeneration system 1230 is used to treat the C02-containing capture solution 111 (e.g., spent capture solution) to recover and / or concentrate the C02 content contained in the C02-containing capture solution 111.

[0238] The CO2-containing capture solution 111 flows from the gas-liquid contactor 100, 100A, 100B to a pellet reactor 1210 of a DAC system 1200. A slurry of calcium hydroxide 1224 is injected into the pellet reactor 1210. A reaction between the CO2-containing capture solution 111 and the calcium hydroxide 1224 occurs in the pellet reactor. Ca 2+ In the pellet reactor 1210, the CO3 2- reacts to form calcium carbonate solids and an aqueous alkaline solution as a CO2capture solution 114 (e.g., a hydroxide), thereby regenerating the CO2capture solution 114. For example, potassium carbonate in the CO2-containing capture solution 111 can react with calcium hydroxide to form calcium carbonate and potassium hydroxide, thereby regenerating the CO2capture solution 114 comprising potassium hydroxide.

[0239] The reaction of the CO2-containing capture solution 111 with Ca(OH)2results in precipitation of calcium carbonate (CaCO3) onto calcium carbonate particles in the pellet reactor 1210. Further processing of the calcium carbonate solids, including but not limited to filtration, dewatering, or drying, can be performed prior to sending the calcium carbonate solids to downstream processing units. A stream of calcium carbonate solids 1214 is transported from the pellet reactor 1210 to a calciner 1216 of the DAC system 1200. The calciner 1216 calcines the calcium carbonate in the stream 1214 from the pellet reactor 1210, such that a gaseous CO2stream 1218 and a calcium oxide (CaO) 1220 stream can be produced by oxygen combustion of a fuel source in the calciner 1216. The gaseous CO2stream 1218 is processed for sequestration or other uses, thereby removing some of the CO2from the CO2-containing air 101 that is processed in the gas-liquid contactor 100, 100A, 100B. The gaseous CO2stream 1218, directly or after processing, can be provided as a product stream for use as needed or for export. The stream of calcium oxide (CaO) 1220 is slaked with water in a slaker 1222 of the DAC system 1200 to produce a slurry of calcium hydroxide 1224, which is provided to the pellet reactor 1210. The DAC system 1200 can include multiple gas-liquid contactors 100, 100A, 100B, where each gas-liquid contactor 100, 100A, 100B forms a unit of a series / assembly of gas-liquid contactors 100, 100A, 100B.

[0240] The calcium carbonate solids stream 1214 calcined in calciner 1216 of DAC system 1200 can be produced according to other techniques for capturing CO2 from CO2-containing air 101. For example, in one possible implementation, the gas-liquid contactors 100, 100A, 100B of DAC system 1200 use a liquid absorbent, and the carbonate-forming reactor that receives the CO2-containing capture solution 111 includes one or more reactors similar to those used in a Kraft pulping process to form calcium carbonate solids. In some examples, DAC system 1200 does not have a causticization process, and the gas-liquid contactors 100, 100A, 100B of DAC system 1200 use a liquid absorbent (such as a calcium hydroxide slurry) and contact it with air to form a stream 1214 of calcium carbonate solids, which is then calcined.

[0241] In some implementations, the CO2 capture solution 114 can be regenerated using a different regeneration system. The regeneration system 1230 can be part of or separate from the gas-liquid contactors 100, 100A, 100B. Referring to FIG. 1, the CO2 capture solution 114 can be regenerated in the regeneration system 1230 and then returned to the gas-liquid contactors 100, 100A, 100B. Figure 15 In an example alternative regeneration system 1235, the CO2-containing capture solution 111 can be flowed to an electrochemical system that includes a cell stack that can include one or more membranes and a set of electrodes in an array (see, e.g., FIG. 2). The electrochemical system can regenerate the CO2 capture solution 114 from the CO2-containing capture solution 111 by applying an electrical potential to an electrolyte that includes the CO2-containing capture solution 111. The potential difference causes an ion exchange, thereby forming the recovered CO2 1218 and regenerating the CO2 capture solution 114. Figure 20 ) The electrochemical system can regenerate the CO2 capture solution 114 from the CO2-containing capture solution 111 by applying an electrical potential to an electrolyte that includes the CO2-containing capture solution 111. The potential difference causes an ion exchange, thereby forming the recovered CO2 1218 and regenerating the CO2 capture solution 114.

[0242] In another possible implementation of the alternative regeneration system 1235, the CO2-containing capture solution 111 can be flowed to a thermal stripping column that uses steam to desorb CO2 from the CO2-containing capture solution 111, thereby forming a recovered CO2 stream 1218 and regenerating the CO2 capture solution 114 (e.g., a CO2-lean liquid). For example, Figure 19 The DAC system 1900 includes one or more gas-liquid contactors 100, 100A, 100B and a regeneration subsystem 1980. The regeneration subsystem 1980 is configured to regenerate a CO2 capture solution (e.g., the CO2 capture solution 114).

[0243] In embodiments in which the CO2capture solution 114 includes an amine capture species, the CO2in the CO2-containing air 101 reacts with the amine capture species to form a CO2-containing capture solution 111 that includes a carbamate salt. Non-limiting examples of amine capture species of the CO2capture solution 114 include furan-bis(iminoguanidine) (FuBIG), isophorone diamine (IPDA), hindered amines with alkanolamines and alcohol hydroxyl groups. Examples of alkanolamines include monoethanolamine (MEA), diethanolamine, triethanolamine, methyldiethanolamine, diisopropanolamine, and diglycolamine. Examples of hindered amines with alcohol hydroxyl groups include 2-amino-2-methyl-1 -propanol (AMP), 2-(ethylamino)-ethanol (EAE), and 2-(methylamino)-ethanol (MAE).

[0244] The regeneration subsystem 1980 includes at least a concentrator 505, a heat exchanger 509, and a regeneration reactor 507. The CO2-containing capture solution 111 can include solids (e.g., carbamate solids) and be in the form of a slurry. The slurry flows to the concentrator 505, which functions to increase the concentration of solids by separating the solids from the liquid. The concentrator 505 produces a solid slurry stream 521. The solid slurry stream 521 includes a higher concentration of solids than the concentration of solids in the CO2-containing capture solution 111. At least some of the liquid separated from the CO2-containing capture solution 111 by the concentrator 505 forms a separated liquid stream 523, which can include unreacted CO2capture solution 114. The separated liquid stream 523 flows back to any suitable component or unit of the gas-liquid contactor 100, 100A, 100B.

[0245] With reference to Figure 19from the regenerated lean CO2 capture solution 511 to the solid slurry stream 521, as described below. The heated solid slurry stream 521 flows from the heat exchanger 509 to the regeneration reactor 507. The heat exchanger 509 can be considered a pre-heat exchanger that thermally integrates the concentrated slurry (e.g., the solid slurry stream 521) with the higher temperature regenerated capture solution (e.g., the lean CO2 capture solution 511). In an exemplary embodiment, the solids in the heated solid slurry stream 521 are at least partially regenerated, releasing CO2, in the heat exchanger 509 or downstream thereof, prior to entering the regeneration reactor 507. In an exemplary embodiment, the heat exchanger 509 is upstream of the concentrator 505 relative to the flow direction of the CO2-containing capture solution 111 from the gas-liquid contactor 100, 100A, 100B to the concentrator 505. In such embodiments, the heat exchanger 509 is used to transfer heat energy from the lean CO2 capture solution 511 to the CO2-containing capture solution 111 prior to the solid-liquid separation in the concentrator 505. In embodiments where heat is used in the regeneration reactor 507 to regenerate the CO2-containing capture solution 111, the heat exchanger 509 helps to reduce the load on the regeneration reactor 507 in the process of transferring heat energy to the stream entering the regeneration reactor 507. In other embodiments, the regeneration subsystem 1980 is devoid of a heat exchanger.

[0246] In embodiments where the regeneration reactor 507 is or includes a packed column, the heated solid slurry stream 521 flows through the packing 503 within the regeneration reactor 507. The regeneration heater 506 provides a source of heat, such as a stream of heated gas 517 (e.g., steam), that contacts the heated solid slurry stream 521 flowing along the packing 503. In an exemplary embodiment, the regeneration reactor 507 includes one or more nozzles for flowing the heated solid slurry stream 521 onto the packing 503. In alternative embodiments, the regeneration reactor 507 includes a column with trays instead of or in addition to a packed column. In an exemplary embodiment, the packing 503 is non-structured (e.g., random packing).

[0247] By contacting the heated solid slurry stream 521 and its carbamate solids with the heated gas stream 517, a lean CO2 capture solution 511 (e.g., a regenerated CO2 capture solution 114) is produced and CO2 gas 519 is desorbed. The lean CO2 capture solution 511 collects at the bottom of the regeneration reactor 507. Referring to FIG. 5, the lean CO2 capture solution 511 flows from the regeneration reactor 507 to the heat exchanger 509, where heat energy is transferred from the lean CO2 capture solution 511 to the solid slurry stream 521. The heated solid slurry stream 521 flows from the heat exchanger 509 to the concentrator 505, where the solid slurry stream 521 is separated into a concentrated solid stream 523 and a concentrated liquid stream 525. The concentrated solid stream 523 flows from the concentrator 505 to the heat exchanger 509, where heat energy is transferred from the concentrated solid stream 523 to the lean CO2 capture solution 511. The concentrated liquid stream 525 flows from the concentrator 505 to the heat exchanger 509, where heat energy is transferred from the concentrated liquid stream 525 to the lean CO2 capture solution 511. The concentrated solid stream 523 and the concentrated liquid stream 525 are combined into the solid slurry stream 521, which flows from the heat exchanger 509 to the regeneration reactor 507. Figure 19The CO2-lean capture solution 511 is at a relatively high temperature and is flowed to the heat exchanger 509 to transfer at least a portion of its thermal energy to the solid slurry stream 521 flowing from the concentrator 505, as described above. In embodiments where the regeneration subsystem 1980 does not have a heat exchanger, the CO2-lean capture solution 511 is directly flowed to one or more components of the gas-liquid contactor 100, 100A, 100B and reused in the gas-liquid contactor 100, 100A, 100B for CO2 capture.

[0248] The CO2 gas 519 is released from the regeneration reactor 507 along with the water vapor 518 through a gas discharge line. The combined gas stream (CO2 gas 519 and water vapor 518) is flowed from the regeneration reactor 507 to the condenser 508. Depending on the capture material of the CO2 capture solution 114, the combined gas stream can also include volatile amines / organics. The condenser 508 condenses the water vapor 518 (and volatile amines / organics) to form a water stream 1920 (which can have condensable amines / organics) and separates the CO2 gas 519 from the water stream 1920. The CO2 gas 519 is released from the condenser 508 as a CO2 product stream 525. The CO2 product stream 525 can be treated or processed as desired, for example by compression. The compressed CO2 product stream 525, either directly or after treatment, can be provided as desired for use or for export. In an exemplary embodiment, the condensed water stream 1920 is flowed from the condenser 508 to the regeneration heater 506 for use in generating the heated gas stream 517 in the regeneration reactor 507. In an exemplary embodiment, the condensed water stream 1920 is directly flowed to the heat exchanger 509.

[0249] Other configurations of the regeneration reactor 507 are possible. For example, in some configurations, the regeneration reactor 507 does not include a packed column, and thus no packing. In such configurations, the regeneration reactor 507 can be or can include any one of the following non-limiting examples of a reaction vessel: a tubular reactor, a continuous stirred tank reactor (CSTR), in which reagents, reactants, and solvents flow into the reactor while reaction products exit the vessel simultaneously, or a fluidized bed reactor. In embodiments in which the regeneration reactor 507 is or includes a tubular reactor, the tubular reactor can have internal heating means (e.g., electrical heating elements) and / or external heating means (e.g., heating jackets), an inlet and an outlet, and a phase separator or other suitable outlet to allow CO2to degas from the tubular reactor. In embodiments in which the regeneration reactor 507 is or includes a CSTR, the CSTR can have internal heating means (e.g., electrical heating elements) and / or external heating means (e.g., heating jackets), mixing elements (e.g., rotors and / or baffles), an inlet and an outlet, and a phase separator or other suitable outlet to allow CO2to degas from the CSTR. In embodiments in which the regeneration reactor 507 is or includes a fluidized bed reactor, the solid slurry stream 521 can enter the fluidized bed reactor from the top of the reactor, and a heating medium (e.g., steam) can be externally heated and flowed to the fluidized bed reactor to fluidize and heat the bed of solids. The fluidized bed reactor can have a distributor plate or grid at its bottom to support the fluidized solids. The fluidized bed reactor can also have an inlet and an outlet, and a phase separator or other suitable outlet to allow CO2to degas from the fluidized bed reactor.

[0250] In another possible embodiment of the alternative regeneration system 1235, Figure 20 The DAC system 2000 of FIG. 21 includes a regeneration subsystem 2080. The regeneration subsystem 2080 is configured to regenerate the CO2-containing sorbent (e.g., the CO2-containing capture solution 111) received from the one or more gas-liquid contactors 100, 100A, 100B. The gas-liquid contactors 100, 100A, 100B are fluidly connected to the product generation subsystem 606 by the carbonate separation subsystem 604. The gas-liquid contactors 100, 100A, 100B provide the CO2-containing capture solution 111 to the carbonate separation subsystem 604.

[0251] The CO2-containing capture solution 111 can be an aqueous mixture comprising primarily carbonate ions, an alkali metal carbonate (e.g., K2CO3, Na2CO3), or a combination thereof. The CO2-containing capture solution 111 can also include lesser amounts of other components, such as hydroxide ions, an alkali metal hydroxide (e.g., KOH, NaOH), water, and impurities. For example, the CO2-containing capture solution 111 can include 0.4 M to 6 M K2CO3 and 1 M to 10 M KOH. In an example embodiment, the CO2-containing capture solution 111 can include an aqueous Na2CO3-NaOH mixture. In an example embodiment, the CO2-containing capture solution 111 can include a mixture of K2CO3 and Na2CO3.

[0252] In an example embodiment, the carbonate separation subsystem 604 can include a caustic evaporator or a crystallizer (or both). In an example embodiment, the carbonate separation subsystem 604 can include a nanofiltration unit or a crystallizer (or both). The carbonate separation subsystem 604 produces a crystalline carbonate hydrate 614. The crystalline carbonate hydrate 614 can include a carbonate monohydrate (M2CO3-1.5H2O) or an anhydrous carbonate. For example, the crystalline carbonate hydrate 614 can include a monohydrate potassium carbonate (K2CO3-1.5H2O). In some examples, the crystalline carbonate hydrate 614 can include a decahydrate sodium carbonate (Na2CO3-10H2O). In some examples, the crystalline carbonate hydrate 614 can include a hexahydrate potassium sodium carbonate (KNaCO3-6H2O). In an example embodiment, the crystalline carbonate hydrate 614 can include a different stoichiometry of water molecules per unit of carbonate in the crystalline carbonate (e.g., M2CO3-n H2O, where M is an alkali metal and n is an integer or fractional value).

[0253] The product generation subsystem 606 receives the crystalline carbonate hydrate 614. In an example embodiment, the product generation subsystem 606 includes a dissolution tank 608 fluidly coupled to an electrochemical cell 610. In an example embodiment, the product generation subsystem 606 can include a caustic evaporator.

[0254] The dissolution tank 608 can receive the crystalline carbonate hydrate 614 from the carbonate separation subsystem 604, a water stream 620, and a brine stream 622. In an example embodiment, a polished aqueous solution can be used in place of or in addition to the water stream 620. The polished aqueous solution can be substantially free of particulates and dissolved contaminants. The crystalline carbonate hydrate 614 dissolves in the water, and the bicarbonate HCO3 - In combination, the feed solution 616 is formed. The feed solution 616 can include bicarbonate HCO3- A solution that is a mixture of other components such as carbonates and water.

[0255] Electrochemical cell 610 receives feed solution 616 and water stream 620. Electrochemical cell 610 produces at least two product streams, including a first product stream 626 containing hydroxide (regenerated CO2 capture solution 114), which is returned to gas-liquid contactors 100, 100A, 100B for reuse. A second product stream 628 is fed to flash tank 612, where gaseous CO2 product stream 624 is partially or completely released from flash tank 612 and fed to one or more downstream processing units (e.g., compression unit, electroreduction subsystem, carbon product manufacturing system, syngas generation reactor). For further details and alternative embodiments, refer to patent application entitled "Systems and methods for capturing carbon dioxide and regenerating a capturesolution," publication number US2022 / 0362707 A1, the entire contents of which are incorporated herein by reference.

[0256] Regeneration systems 1230, 1980, and 2080 may include components such as liquid distribution lines, solids conveying devices, filtration systems, intermediate components (e.g., storage containers), and / or components that work together to regenerate the CO2 capture solution 114. Regeneration systems 1230, 1980, and 2080 also include pumps for allowing liquid to flow into and out of the regeneration systems 1230, 1980, and 2080.

[0257] refer to Figure 16 A method 1400 for capturing CO2 from atmospheric air is disclosed. At 1402, method 1400 includes flowing atmospheric air (e.g., CO2-containing air 101) along a first flow direction (e.g., ATD 138D) from the leading edge 136A to the trailing edge 136B of packing sheets 130, 630, 730, 830. The first flow direction is substantially perpendicular to the leading edge 136A. At 1404, method 1400 includes flowing a CO2 capturing solution 114 over packing sheets 130, 630, 730, 830 in a second flow direction (e.g., LTD 138L) to absorb CO2 from atmospheric air into the CO2 capturing solution 114. The second flow direction is substantially perpendicular to the first flow direction.

[0258] Figure 17is a schematic diagram of a control system (or controller) 1600 for a gas-liquid contactor, such as the gas-liquid contactors 100, 100A, 100B disclosed herein. The system 1600 can be used in connection with the operations described in association with any of the computer-implemented methods previously described, e.g., as the control system 999 or other controllers described herein or as part of the control system 999 or other controllers described herein.

[0259] The system 1600 is intended to include various forms of digital computer, such as a laptop computer, desktop computer, workstation, personal digital assistant, server, blade server, mainframe, and other appropriate computers. The system 1600 can also include mobile devices, such as personal digital assistants, cellular telephones, smartphones, and other like computing devices. Additionally, the system can include portable storage media, such as a Universal Serial Bus (USB) flash drive. For example, the USB flash drive can store an operating system and other applications. The USB flash drive can include an input / output component, such as a wireless transmitter or USB connector, that can be inserted into a USB port of another computing device.

[0260] The system 1600 includes a processor 510, a memory 520, a storage device 530, and an input / output device 540. Each of the components 510, 520, 530, and 540 are interconnected using a system bus 550. The processor 510 is capable of processing instructions for execution within the system 1600. The processor 510 can be designed using a variety of architectures. For example, the processor 510 can be a CISC (Complex Instruction Set Computer) processor, a RISC (Reduced Instruction Set Computer) processor, or a MISC (Minimal Instruction Set Computer) processor.

[0261] In one embodiment, the processor 510 is a single-threaded processor. In some embodiments, the processor 510 is a multi-threaded processor. The processor 510 is capable of processing instructions stored in the memory 520 or on the storage device 530 to display graphical information for a user interface on the input / output device 540.

[0262] The memory 520 stores information within the system 1600. In one embodiment, the memory 520 is a computer-readable medium. In one embodiment, the memory 520 is a volatile memory unit. In some embodiments, the memory 520 is a non-volatile memory unit.

[0263] The storage device 530 is capable of providing mass storage for the system 1600. In one embodiment, the storage device 530 is a computer-readable medium. In various different embodiments, the storage device 530 can be a floppy disk device, a hard disk device, an optical disk device, or a tape device.

[0264] Input / output devices 540 provide input / output operations for system 1600. In one implementation, input / output devices 540 include a keyboard and / or pointing devices such as a mouse. In some implementations, input / output devices 540 include a display unit for displaying graphical user interfaces.

[0265] Certain of the described features can be implemented in digital electronic circuitry, or in computer hardware, firmware, software, or in combinations of them. The apparatus can be implemented in a computer program product tangibly embodied in an information carrier, e.g., in a machine-readable storage device for execution by a programmable processor; and method steps can be performed by an apparatus of logical hardware, e.g., a programmable processor, which acts on information by manipulating and transforming it. The described features can be implemented advantageously in one or more computer programs that are executable on a programmable system including at least one programmable processor coupled to receive data and instructions from, and to transmit data and instructions to, a data storage system, at least one input device, and at least one output device. A computer program is a set of instructions that can be used directly or indirectly in a computer to perform a certain activity or bring about a certain result. Computer programs can be written in any form of programming language, including compiled or interpreted languages, and they can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment.

[0266] By way of example, a suitable processor for executing an instruction program includes both general and special purpose microprocessors, and any type of computer processor or unique processor for the specific application including a single processor or one of multiple processors of any kind of a computer. Generally, a processor will receive instructions and data from a read-only memory or a random access memory or both. The essential elements of a computer are a processor for executing instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or input to, or to

[0267] To provide for interaction with a user, the features can be implemented on a computer having a display device such as a CRT (cathode ray tube) or LCD (liquid crystal display) monitor for displaying information to the user and a keyboard and a pointing device such as a mouse or a trackball by which the user can provide input to the computer. Additionally, such activities can be implemented via touch screen display and other appropriate mechanisms.

[0268] The features can be implemented in a controlling system that includes a back-end component, such as a data server, or that includes a middleware component, such as an application server or an Internet server, or that includes a front-end component, such as a client computer having a graphical user interface or a Web browser through which a user can interact with an implementation, or any combination of them. The components of the system can be connected by any form or medium of digital data communication such as a communication network. Examples of communication networks include a local area network ("LAN"), a wide area network ("WAN"), peer-to-peer networks (having ad hoc or static members), grid computing infrastructures, and the Internet.

[0269] A number of embodiments of the application have been described. Nevertheless, it will be understood that various modifications can be made without departing from the spirit and scope of the disclosure. Accordingly, other embodiments are within the scope of the following claims. Further modifications and alternative embodiments will be apparent to one of ordinary skill in the art in view of this description. Therefore, this description should be construed in a non-limiting sense. It is to be understood that the forms shown and described are examples only of the many forms that the application can take. Elements and materials can be substituted for those illustrated and described herein, parts and processes can be reversed, and certain features can be utilized independently, all as would be apparent to one of ordinary skill in the art, having the benefit of this description. Changes can be made in the elements described herein without departing from the spirit and scope of the following claims.

Claims

1. A packing sheet for transferring CO2 from atmospheric air to a CO2 capture solution, characterized in that, The filler sheet includes: a first side; a second side opposite the first side; a leading edge parallel to a vertical direction in a mounted configuration of the filler sheet; a trailing edge spaced apart from the leading edge by an air travel depth parallel to a direction in which the atmospheric air travels from the leading edge to the trailing edge; a plurality of interconnected edges including: an upper edge extending between the leading edge and the trailing edge; and a lower edge extending between the leading edge and the trailing edge, the upper edge and the lower edge spaced apart by a liquid travel dimension parallel to a direction in which the CO2 capture solution travels from the upper edge to the lower edge; a mass transfer zone disposed on the first side and the second side between the leading edge, the trailing edge, the upper edge, and the lower edge, the mass transfer zone including a plurality of mass transfer microstructures configured to receive the CO2 capture solution and contact the atmospheric air with the CO2 capture solution, the plurality of mass transfer microstructures having a microstructure height; a plurality of reinforcement elements extending outwardly from the first side and the second side, each reinforcement element of the plurality of reinforcement elements having an orientation parallel to the liquid travel dimension; and a plurality of spacers disposed on the mass transfer zone and extending outwardly from the first side and the second side, the plurality of spacers spaced apart along the liquid travel dimension and having a spacer height greater than the microstructure height.

2. The filler sheet of claim 1, wherein Further included are spacer alignment axes extending on the first side and the second side between the upper edge and the lower edge, the spacer alignment axes extending between at least two spacers of the plurality of spacers aligned along the liquid travel dimension, the spacer alignment axes parallel to a vertical direction in a mounted configuration of the filler sheet.

3. The filler sheet according to claim 1 or 2, characterized in that Further included are reinforcement element alignment axes extending on the first side and the second side between the upper edge and the lower edge, the reinforcement element alignment axes extending between at least two reinforcement elements of the plurality of reinforcement elements aligned along the liquid travel dimension, the reinforcement element alignment axes parallel to a vertical direction in a mounted configuration of the filler sheet.

4. The filler sheet of claim 1, wherein The plurality of reinforcement elements includes a plurality of intermediate reinforcement elements between the leading edge and the trailing edge, the plurality of intermediate reinforcement elements including a plurality of intermediate reinforcement bodies positioned adjacent to each other along the liquid travel dimension, each intermediate reinforcement body of the plurality of intermediate reinforcement bodies extending outwardly from one of the first side and the second side to an attachment wall, the attachment wall defining a reinforcement body height greater than the microstructure height.

5. The filler sheet of claim 4, wherein The plurality of intermediate reinforcements includes a first set of intermediate reinforcements extending outward from the first side and a second set of intermediate reinforcements extending outward from the second side, the first set of intermediate reinforcements forming a first set of recesses on the second side, the second set of intermediate reinforcements forming a second set of recesses on the first side, the first set of intermediate reinforcements alternating along an axis with the second set of recesses on the first side, and the second set of intermediate reinforcements alternating along the axis with the first set of recesses on the second side.

6. The filler sheet according to claim 4 or 5, characterized in that Each intermediate reinforcement of the plurality of intermediate reinforcements includes a plurality of planar walls extending outward from one of the first side and the second side to the attachment wall; and a plurality of flow channels, each flow channel of the plurality of flow channels disposed in a planar wall of the plurality of planar walls.

7. The filler sheet of claim 6, wherein The plurality of flow channels includes at least one longitudinal flow channel parallel to the liquid travel dimension; and at least one lateral flow channel including an inlet end and an outlet end, the inlet end closer to the attachment wall than the outlet end.

8. The filler sheet of claim 1, wherein The plurality of reinforcing elements includes a plurality of perimeter ribs adjacent to at least one of the trailing edge and the leading edge, each perimeter rib of the plurality of perimeter ribs extending outward from one of the first side and the second side and forming a respective recess in the other of the first side and the second side.

9. The filler sheet of claim 8, wherein The plurality of perimeter ribs includes a plurality of leading edge ribs adjacent to the leading edge, the plurality of leading edge ribs including a set of innermost ribs extending outward from the first side and forming respective recesses in the second side; and a set of outermost ribs extending outward from the second side and forming respective recesses in the first side, spaced further from the leading edge along the air travel depth than the set of innermost ribs.

10. The filler sheet according to claim 8 or 9, characterized in that The plurality of perimeter ribs includes a plurality of trailing edge ribs adjacent to the trailing edge, the plurality of trailing edge ribs including a third set of ribs extending outward from the first side and forming respective recesses in the second side; and a fourth set of ribs extending outward from the second side and forming respective recesses in the first side, spaced further from the trailing edge along the air travel depth than the third set of ribs.

11. The filler sheet according to claim 8 or 9, characterized in that The plurality of perimeter ribs includes at least one longitudinal pair of ribs having two perimeter ribs spaced apart from one another in a direction parallel to the liquid travel dimension to define a longitudinal pairing gap, wherein some of the plurality of mass transfer microstructures are present in the longitudinal pairing gap.

12. The filler sheet according to claim 8 or 9, characterized in that The plurality of perimeter ribs includes at least one lateral pair of ribs having two perimeter ribs spaced apart from one another in a direction parallel to the air travel depth to define a lateral pairing gap, and some of the plurality of mass transfer microstructures are present in the lateral pairing gap.

13. The filler sheet according to claim 1 or 2, characterized in that The plurality of reinforcement elements includes a plurality of perimeter reinforcements positioned adjacent to one another along the liquid travel dimension, the plurality of perimeter reinforcements defining at least one of the trailing edge and the leading edge.

14. The filler sheet of claim 1 or 2, wherein The plurality of spacers includes a plurality of pairs of spacers spaced apart along the liquid travel dimension and along the air travel depth, the spacers in each of the pairs of spacers spaced apart in a direction parallel to the air travel depth.

15. The filler sheet of claim 14, wherein, The spacers in each of the pairs of spacers include a first spacer extending outward from the first side and forming a respective recess in the second side, and a second spacer extending outward from the second side and forming a respective recess in the first side.

16. The filler sheet of claim 1 or 2, wherein The plurality of reinforcement elements includes a plurality of intermediate reinforcement elements positioned between the leading edge and the trailing edge, at least the plurality of intermediate reinforcement elements including a plurality of intermediate ribs having an orientation parallel to the liquid travel dimension, the plurality of intermediate ribs including a first set of ribs spaced apart along the liquid travel dimension and extending outward from the first side and forming respective recesses in the second side; and a second set of ribs spaced apart along the liquid travel dimension and extending outward from the second side and forming respective recesses in the first side, the second set of ribs spaced apart from the first set of ribs in a direction parallel to the air travel depth.

17. The filler sheet of claim 16, wherein: each rib in the first set of ribs includes a first rib end and a second rib end; and each rib in the second set of ribs includes a third rib end and a fourth rib end, the third rib end of at least one rib in the second set of ribs positioned between the first rib end and the second rib end of at least one rib in the first set of ribs.

18. The filler sheet of claim 1 or 2, wherein The filler sheet has a rectangular shape, the leading edge and the trailing edge substantially parallel to a vertical direction in a mounted configuration of the filler sheet, the upper edge perpendicular to the leading edge and the trailing edge, and the lower edge perpendicular to the leading edge and the trailing edge.

19. The filler sheet of claim 1 or 2, wherein The liquid travel dimension is greater than the air travel depth.

20. The filler sheet of claim 1 or 2, wherein The air travel depth is 3 feet to 5 feet.

21. The filler sheet of claim 1 or 2, wherein At least some of the plurality of mass transfer microstructures include a first wall portion extending toward a first apex on the first side; and a second wall portion extending from the first apex to a second apex on the second side, at least one of the first wall portion and the second wall portion including at least one wall feature extending from the at least one of the first wall portion and the second wall portion.

22. The filler sheet of claim 21, wherein, The at least one wall feature includes a first wall feature extending outward from the first wall portion on the first side; and a second wall feature extending outward from the second wall portion on the second side.

23. The filler sheet of claim 1 or 2, wherein Further comprising a center of mass, the filler sheet having point symmetry about the center of mass.

24. The filler sheet of claim 1, wherein The plurality of reinforcement elements includes a plurality of reinforcements positioned adjacent to one another along the air travel depth and between the leading edge and the trailing edge.

25. The filler sheet of claim 24, wherein, The plurality of reinforcements is disposed between the upper edge and the lower edge.

26. The filler sheet of claim 24, wherein The plurality of reinforcements define at least one of the upper edge and the lower edge.

27. The filler sheet of any one of claims 24 to 26, wherein, Each of the plurality of reinforcements extends outward from at least one of the first side or the second side to an attachment wall, the attachment wall defining a body height that is greater than the microstructure height.

28. The filler sheet of claim 27, wherein, The plurality of reinforcements includes a first set of reinforcements extending outward from the first side and a second set of reinforcements extending outward from the second side, the first set of reinforcements forming a first set of depressions on the second side, the second set of reinforcements forming a second set of depressions on the first side, the first set of reinforcements alternating along a horizontal axis with the second set of depressions on the first side, and the second set of reinforcements alternating along the horizontal axis with the first set of depressions on the second side.

29. The filler sheet of claim 27, wherein, Each of the plurality of reinforcements includes: a plurality of planar walls extending outward from at least one of the first side or the second side to the attachment wall; and at least one flow channel extending into one of the plurality of planar walls on at least one of the first side or the second side, the at least one flow channel being parallel to the air travel depth.

30. The filler sheet of claim 27, wherein, Each of the plurality of reinforcements includes a plurality of planar walls extending outward from at least one of the first side or the second side to the attachment wall, the attachment wall having an attachment wall slope, at least one of the plurality of planar walls including a stepped member, the stepped member including: a first wall segment extending from the attachment wall and having a first slope that is different than the attachment wall slope; a second wall segment extending from the first wall segment and having a second slope that is different than the first slope; and a third wall segment extending from the second wall segment and having a third slope that is different than the second slope.

31. The filler sheet of claim 1, wherein At least some of the plurality of mass transfer microstructures include: a plurality of base microstructures including a first wall portion and a second wall portion extending toward a first apex on one of the first side and the second side; and a plurality of supplemental microstructures protruding outward from the first wall portion and the second wall portion of the plurality of base microstructures.

32. A structured packing for transferring CO2 from atmospheric air to a CO2 capture solution, characterized in that, The structured packing includes: a plurality of packing pieces attached together, at least one of the plurality of packing pieces including: a first side; a second side opposite the first side; a leading edge; a trailing edge spaced apart from the leading edge by an air travel depth, the air travel depth being parallel to a direction of atmospheric air travel from the leading edge to the trailing edge, in an installed configuration of the at least one packing piece, the leading edge of the at least one packing piece being parallel to a vertical direction; a plurality of interconnecting edges including: an upper edge extending between the leading edge and the trailing edge; and a lower edge extending between the leading edge and the trailing edge. a lower edge extending between the leading edge and the trailing edge, the upper edge and the lower edge being spaced apart by a liquid travel dimension parallel to a direction along which the CO2 capture solution travels from the upper edge to the lower edge; a mass transfer zone disposed on the first side and the second side between the leading edge, the trailing edge, the upper edge, and the lower edge, the mass transfer zone comprising a plurality of mass transfer microstructures having a microstructure height and configured to contact the CO2 capture solution with the atmospheric air; a plurality of reinforcement elements extending outwardly from the first side and the second side, each reinforcement element of the plurality of reinforcement elements having an orientation parallel to the liquid travel dimension; and a plurality of spacers disposed on the mass transfer zone and extending outwardly from the first side and the second side, the plurality of spacers being spaced apart along the liquid travel dimension and having a spacer height greater than the microstructure height, adjacent packing sheets of the plurality of packing sheets being attached along a respective plurality of spacers and defining an airflow channel through which atmospheric air travels from the leading edge to the trailing edge.

33. The structured packing of claim 32 wherein, the airflow channel has a rectangular channel shape defined in a plane perpendicular to the liquid travel dimension.

34. The structured packing of claim 32 or 33, wherein, the plurality of reinforcement elements includes a plurality of intermediate reinforcement elements between the leading edge and the trailing edge, the plurality of intermediate reinforcement elements including a plurality of intermediate reinforcement bodies positioned adjacent to each other along the liquid travel dimension, each intermediate reinforcement body of the plurality of intermediate reinforcement bodies extending outwardly from one of the first side and the second side to an attachment wall defining a reinforcement body height, the reinforcement body height being greater than the microstructure height, adjacent packing sheets being attached along their attachment walls.

35. The structured packing of claim 34 wherein, each intermediate reinforcement body of the plurality of intermediate reinforcement bodies includes a plurality of planar walls extending outwardly from one of the first side and the second side to the attachment wall and a plurality of flow channels, each flow channel of the plurality of flow channels being disposed in a planar wall of the plurality of planar walls, the plurality of flow channels including at least one longitudinal flow channel parallel to the liquid travel dimension and extending from the attached attachment walls of the adjacent packing sheets.

36. The structured packing of claim 34 wherein, the plurality of intermediate reinforcement bodies includes a first set of reinforcement bodies extending outwardly from the first side and a second set of reinforcement bodies extending outwardly from the second side, the first set of reinforcement bodies forming a first set of recesses on the second side and the second set of reinforcement bodies forming a second set of recesses on the first side, the first set of reinforcement bodies alternating with the second set of recesses on the first side along an axis and the second set of reinforcement bodies alternating with the first set of recesses on the second side along the axis, the airflow channel between the adjacent packing sheets extending through the first set of recesses and the second set of recesses.

37. The structured packing of claim 32 or 33, wherein: The plurality of reinforcing elements includes a plurality of intermediate reinforcing elements between the leading edge and the trailing edge, at least the plurality of intermediate reinforcing elements including a plurality of intermediate ribs having an orientation parallel to the liquid travel dimension; The plurality of reinforcing elements includes a plurality of perimeter reinforcing elements disposed proximate at least one of the trailing edge and the leading edge, the plurality of perimeter reinforcing elements including a plurality of perimeter reinforcing bodies positioned adjacent to each other along the liquid travel dimension, the plurality of perimeter reinforcing bodies defining at least one of the trailing edge and the leading edge; and An intermediate rib height of the plurality of intermediate ribs is less than a perimeter reinforcing body height of the plurality of perimeter reinforcing bodies.

38. The structured packing of claims 32 or 33, wherein, The plurality of reinforcing elements includes a plurality of perimeter reinforcing bodies positioned adjacent to each other along the liquid travel dimension, the plurality of perimeter reinforcing bodies defining at least one of the trailing edge and the leading edge, the plurality of perimeter reinforcing bodies including a first set of reinforcing bodies extending outward from the first side and a second set of reinforcing bodies extending outward from the second side, the first set of reinforcing bodies forming a first set of recesses on the second side and the second set of reinforcing bodies forming a second set of recesses on the first side, the first set of reinforcing bodies alternating along an axis with the second set of recesses on the first side and the second set of reinforcing bodies alternating along the axis with the first set of recesses on the second side, the first set of reinforcing bodies of a first one of the adjacent filler sheets attached to the second set of reinforcing bodies of a second one of the adjacent filler sheets forming a reinforcing body flow path between the first set of recesses and the second set of recesses of the adjacent filler sheets, the reinforcing body flow path in fluid communication with the airflow passage.

39. The structured packing of claim 32 wherein, Further included are spacer alignment axes extending on the first side and the second side between the upper edge and the lower edge, the spacer alignment axes extending between at least two of the plurality of spacers aligned along the liquid travel dimension, the spacer alignment axes parallel to a vertical direction in the installed configuration of the at least one filler sheet.

40. The structured packing of claim 39 wherein, Further included are reinforcing element alignment axes extending on the first side and the second side between the upper edge and the lower edge, the reinforcing element alignment axes extending between at least two of the plurality of reinforcing elements aligned along the liquid travel dimension, the reinforcing element alignment axes parallel to a vertical direction in the installed configuration of the at least one filler sheet.

41. The structured packing of any one of claims 39-40, wherein, The plurality of reinforcing elements includes a plurality of intermediate reinforcing elements between the leading edge and the trailing edge, at least the plurality of intermediate reinforcing elements including a plurality of intermediate reinforcing bodies positioned adjacent to each other along the liquid travel dimension, each of the plurality of intermediate reinforcing bodies extending outward from one of the first side and the second side to an attachment wall, the attachment wall defining a reinforcing body height greater than the microstructure height.

42. The structured packing of claim 41 wherein, The plurality of intermediate reinforcements includes a first set of intermediate reinforcements extending outward from the first side and a second set of intermediate reinforcements extending outward from the second side, the first set of intermediate reinforcements forming a first set of recesses on the second side and the second set of intermediate reinforcements forming a second set of recesses on the first side, the first set of intermediate reinforcements alternating along an axis with the second set of recesses on the first side and the second set of intermediate reinforcements alternating along the axis with the first set of recesses on the second side.

43. The structured packing of claim 41 wherein, Each of the plurality of intermediate reinforcements includes a plurality of planar walls extending outward from one of the first side and the second side to the attachment wall and a plurality of flow channels, each of the plurality of flow channels disposed in one of the plurality of planar walls.

44. The structured packing of claim 43 wherein, The plurality of flow channels includes at least one longitudinal flow channel parallel to the liquid travel dimension and at least one lateral flow channel including an inlet end and an outlet end, the inlet end closer to the attachment wall than the outlet end.

45. The structured packing of claim 39 wherein, The plurality of reinforcing elements includes a plurality of perimeter ribs adjacent to at least one of the trailing edge and the leading edge, each of the plurality of perimeter ribs extending outward from one of the first side and the second side and forming a respective recess in the other of the first side and the second side.

46. The structured packing of claim 45 wherein, The plurality of perimeter ribs includes a plurality of leading edge ribs adjacent to the leading edge, the plurality of leading edge ribs including a set of innermost ribs; and a set of outermost ribs spaced further from the leading edge along the air travel depth than the set of innermost ribs, the set of innermost ribs extending outward from the first side and forming respective recesses in the second side, the set of outermost ribs extending outward from the second side and forming respective recesses in the first side.

47. The structured packing of claims 45 or 46, wherein, The plurality of perimeter ribs includes a plurality of trailing edge ribs adjacent to the trailing edge, the plurality of trailing edge ribs including a third set of ribs; and a fourth set of ribs spaced further from the trailing edge along the air travel depth than the third set of ribs, the third set of ribs extending outward from the first side and forming respective recesses in the second side, the fourth set of ribs extending outward from the second side and forming respective recesses in the first side.

48. The structured packing of claims 45 or 46, wherein, The plurality of perimeter ribs includes at least one longitudinal pair of ribs having two perimeter ribs spaced apart from one another in a direction parallel to the liquid travel dimension to define a longitudinal pairing gap, wherein some of the plurality of mass transfer microstructures are present in the longitudinal pairing gap.

49. The structured packing of claims 45 or 46, wherein, The plurality of perimeter ribs includes at least one lateral pair of ribs having two perimeter ribs spaced apart from one another in a direction parallel to the air travel depth to define a lateral pairing gap, and some of the plurality of mass transfer microstructures are present in the lateral pairing gap.

50. The structured packing of claims 39 or 40, wherein, The plurality of reinforcement elements includes a plurality of perimeter reinforcements positioned adjacent to each other along the liquid travel dimension, the plurality of perimeter reinforcements defining at least one of the leading edge and the trailing edge.

51. The structured packing of claims 39 or 40, wherein, The plurality of partitions includes a plurality of partition pairs spaced apart along the liquid travel dimension and along the air travel depth, the partitions in each partition pair spaced apart in a direction parallel to the air travel depth.

52. The structured packing of claim 51 wherein, The partitions in each partition pair include a first partition extending outward from a first side and forming a respective recess in a second side; and a second partition extending outward from the second side and forming a respective recess in the first side.

53. The structured packing of claims 39 or 40, wherein, The plurality of reinforcement elements includes a plurality of intermediate reinforcement elements between the leading edge and the trailing edge, at least the plurality of intermediate reinforcement elements including a plurality of intermediate ribs having an orientation parallel to the liquid travel dimension, the plurality of intermediate ribs including a first set of ribs spaced apart along the liquid travel dimension, the first set of ribs extending outward from the first side and forming respective recesses in the second side; and a second set of ribs spaced apart along the liquid travel dimension, the second set of ribs spaced apart from the first set of ribs in a direction parallel to the air travel depth, the first set of ribs extending outward from the first side and forming respective recesses in the second side, the second set of ribs extending outward from the second side and forming respective recesses in the first side.

54. The structured packing of claim 53 wherein: each rib in the first set of ribs includes a first rib end and a second rib end; and each rib in the second set of ribs includes a third rib end and a fourth rib end, the third rib end of at least one rib in the second set of ribs positioned between the first rib end and the second rib end of at least one rib in the first set of ribs.

55. The structured packing of claim 39 or 40 wherein: the packing sheet has a rectangular shape, the leading edge and the trailing edge parallel to a vertical line in the installed configuration of the at least one packing sheet; the upper edge perpendicular to the leading edge and the trailing edge; and the lower edge perpendicular to the leading edge and the trailing edge.

56. The structured packing of claims 39 or 40, wherein, the liquid travel dimension is greater than the air travel depth.

57. The structured packing of claims 39 or 40, wherein, the air travel depth is 3 feet to 5 feet.

58. The structured packing of claims 39 or 40, wherein, at least one mass transfer microstructure of the plurality of mass transfer microstructures includes a first wall portion extending toward a first apex on the first side; and a second wall portion extending from the first apex to a second apex on the second side, at least one of the first wall portion and the second wall portion including at least one wall feature extending from the at least one of the first wall portion and the second wall portion.

59. The structured packing of claim 58 wherein, the at least one wall feature includes a first wall feature extending outward from the first wall portion on the first side; and a second wall feature extending outward from the second wall portion on the second side.

60. The structured packing of claims 39 or 40, wherein, Further comprising a centroid, the at least one packing sheet having point symmetry about the centroid.

61. A gas-liquid contactor for capturing CO2 from the atmosphere, characterized in that, The gas-liquid contactor comprises: at least one inlet; at least one outlet spaced apart from the at least one inlet; at least one packing section disposed between the at least one inlet and the at least one outlet, the at least one packing section comprising at least one structured packing comprising a plurality of packing sheets attached together, at least one packing sheet of the plurality of packing sheets comprising: a first side; a second side opposite the first side; a leading edge parallel to a vertical direction; a trailing edge spaced apart from the leading edge by an air travel depth; a plurality of interconnecting edges comprising an upper edge extending between the leading edge and the trailing edge; and a lower edge extending between the leading edge and the trailing edge, the upper edge and the lower edge spaced apart by a liquid travel dimension; a mass transfer zone disposed on the first side and the second side between the leading edge, the trailing edge, the upper edge, and the lower edge, the mass transfer zone comprising a plurality of mass transfer microstructures having a microstructure height; a plurality of reinforcement elements extending outwardly from the first side and the second side, each reinforcement element of the plurality of reinforcement elements having an orientation parallel to the liquid travel dimension; and a plurality of spacers disposed on the mass transfer zone and extending outwardly from the first side and the second side, the plurality of spacers spaced apart and having a spacer height greater than the microstructure height, adjacent packing sheets of the plurality of packing sheets attached along a respective plurality of spacers and defining an air flow channel; one or more liquid collection devices comprising a bottom liquid collection device positioned at least partially below the at least one packing section, the one or more liquid collection devices configured to hold a CO2 capture solution; a fan operable to flow atmospheric air (1) from the at least one inlet to the at least one outlet, and (2) parallel to the air travel depth along the air flow channel of the at least one structured packing; and a liquid distribution system fluidly coupled to the at least one packing section and operable to flow the CO2 capture solution along the liquid travel dimension along the plurality of mass transfer microstructures to contact the atmospheric air with the CO2 capture solution and absorb CO2 from the atmospheric air into the CO2 capture solution.

62. The gas-liquid contactor of claim 61, wherein, Further comprising a housing defining an interior at least partially exposed to atmospheric air, the interior disposed between the at least one inlet and the at least one outlet, the at least one structured packing comprising a plurality of structured packings disposed within the interior and forming at least one structured packing arrangement, structured packings of the at least one structured packing arrangement positioned vertically and laterally adjacent to one another.

63. The gas-liquid contactor of claim 62, wherein: the at least one structured packing arrangement comprises an upper arrangement of structured packing; a lower arrangement of structured packing vertically spaced below the upper arrangement of structured packing, and a redistribution gap defined between the upper and lower arrangements of structured packing; and the one or more liquid collection devices comprise a redistribution trough located in the redistribution gap between the upper and lower arrangements of structured packing, the redistribution trough configured to collect CO2 capture solution from the upper arrangement of structured packing and redistribute the CO2 capture solution over the lower arrangement of structured packing.

64. The gas-liquid contactor of claim 62 or 63, wherein, the housing comprises a plurality of interconnected structural members, the plurality of structured packings mounted to at least one of: an interconnected structural member of the plurality of interconnected structural members, and another structured packing of the plurality of structured packings.

65. The gas-liquid contactor of claim 62 or 63, wherein, The liquid distribution system is operable to flow the CO2capture solution at a liquid loading flow rate in the range of 0.5 L / m 2 s to 10 L / m 2 s.

66. The gas-liquid contactor of claim 62 or 63, wherein: the at least one packing section comprises a first packing section; and a second packing section spaced from the first packing section by a plenum; the fan is operable to flow the atmospheric air into the first and second packing sections at an air velocity of 0.1 m / s to 5 m / s and along a horizontal flow direction through the first and second packing sections and into the plenum; and the liquid distribution system is operable to flow the CO2 capture solution at a predominantly vertically downward liquid travel dimension.

67. A packing sheet for transferring CO2 from atmospheric air to a CO2 capture solution, characterized in that, the packing sheet comprises: a first side; a second side opposite the first side; a leading edge; a trailing edge spaced from the leading edge by an air travel depth parallel to a direction of travel of atmospheric air from the leading edge to the trailing edge, the leading edge parallel to a vertical direction in a mounted configuration of the packing sheet; a plurality of interconnected edges comprising an upper edge extending between the leading edge and the trailing edge; and a lower edge extending between the leading edge and the trailing edge, the upper edge and the lower edge spaced by a liquid travel dimension parallel to a direction of travel of the CO2 capture solution from the upper edge to the lower edge; a mass transfer zone disposed on the first and second sides between the leading edge, the trailing edge, the upper edge, and the lower edge, the mass transfer zone comprising a plurality of mass transfer microstructures having a microstructure height, the plurality of mass transfer microstructures configured to receive the CO2 capture solution and contact the atmospheric air with the CO2 capture solution; at least one reinforcing element extending outwardly from one of the first and second sides, the at least one reinforcing element having an orientation parallel to the liquid travel dimension, one or more mass transfer microstructures of the plurality of mass transfer microstructures disposed on the at least one reinforcing element; and a plurality of reinforcing elements extending outwardly from one of the first and second sides, the plurality of reinforcing elements having an orientation parallel to the liquid travel dimension, one or more mass transfer microstructures of the plurality of mass transfer microstructures disposed on the plurality of reinforcing elements. a plurality of spacers disposed on the mass transfer zone and extending outwardly from the first and second sides, the plurality of spacers spaced apart along the liquid travel dimension and having a spacer height that is greater than the microstructure height.

68. A direct air capture system for capturing CO2 from the atmosphere, characterized in that, The direct air capture system includes: at least one gas-liquid contactor including: at least one inlet; at least one outlet spaced apart from the at least one inlet; and at least one packing section disposed between the at least one inlet and the at least one outlet, the at least one packing section including at least one structured packing including a plurality of packing sheets attached together, at least one of the plurality of packing sheets including: a first side; a second side opposite the first side; a leading edge parallel to a vertical direction; a trailing edge spaced apart from the leading edge by an air travel depth; a plurality of interconnecting edges including an upper edge extending between the leading edge and the trailing edge; and a lower edge extending between the leading edge and the trailing edge, the upper edge and the lower edge spaced apart by a liquid travel dimension; a mass transfer zone disposed on the first and second sides between the leading edge, the trailing edge, the upper edge, and the lower edge, the mass transfer zone including a plurality of mass transfer microstructures having a microstructure height; a plurality of reinforcement elements extending outwardly from the first and second sides, each of the plurality of reinforcement elements having an orientation parallel to the liquid travel dimension; and a plurality of spacers disposed on the mass transfer zone and extending outwardly from the first and second sides, the plurality of spacers spaced apart and having a spacer height that is greater than the microstructure height, adjacent ones of the plurality of packing sheets attached along respective ones of the plurality of spacers and defining an air flow channel; a fan operable to flow atmospheric air (1) from the at least one inlet to the at least one outlet and (2) parallel to the air travel depth along the air flow channel of the at least one structured packing; and a liquid distribution system fluidly connected to the at least one packing section and operable to flow a CO2 capture solution through the mass transfer microstructures of the at least one packing section, the CO2 capture solution configured to absorb CO2 from the atmospheric air, the liquid distribution system including one or more liquid collection devices including a bottom liquid collection device at least partially located below the at least one packing section, the one or more liquid collection devices configured to contain the CO2 capture solution; and a regeneration system in fluid communication with the liquid distribution system to receive the CO2 capture solution, the regeneration system configured to regenerate the CO2 capture solution and form a CO2-lean liquid for return to the at least one gas-liquid contactor.

69. The direct air capture system of claim 68, wherein, The regeneration system is configured to provide a CO2 product stream for output or use. the direct air capture system includes: at least one gas-liquid contactor including: at least one inlet; at least one outlet spaced apart from the at least one inlet; and at least one packing section disposed between the at least one inlet and the at least one outlet, the at least one packing section including at least one structured packing including a plurality of packing sheets attached together, at least one of the plurality of packing sheets including: a first side; a second side opposite the first side; a leading edge parallel to a vertical direction; a trailing edge spaced apart from the leading edge by an air travel depth; a plurality of interconnecting edges including an upper edge extending between the leading edge and the trailing edge; and a lower edge extending between the leading edge and the trailing edge, the upper edge and the lower edge spaced apart by a liquid travel dimension; a mass transfer zone disposed on the first and second sides between the leading edge, the trailing edge, the upper edge, and the lower edge, the mass transfer zone including a plurality of mass transfer microstructures having a microstructure height; a plurality of reinforcement elements extending outwardly from the first and second sides, each of the plurality of reinforcement elements having an orientation parallel to the liquid travel dimension; and a plurality of spacers disposed on the mass transfer zone and extending outwardly from the first and second sides, the plurality of spacers spaced apart and having a spacer height that is greater than the microstructure height, adjacent ones of the plurality of packing sheets attached along respective ones of the plurality of spacers and defining an air flow channel; a fan operable to flow atmospheric air (1) from the at least one inlet to the at least one outlet and (2) parallel to the air travel depth along the air flow channel of the at least one structured packing; and a liquid distribution system fluidly connected to the at least one packing section and operable to flow a CO2 capture solution through the mass transfer microstructures of the at least one packing section, the CO2 capture solution configured to absorb CO2 from the atmospheric air, the liquid distribution system including one or more liquid collection devices including a bottom liquid collection device at least partially located below the at least one packing section, the one or more liquid collection devices configured to contain the CO2 capture solution; and a regeneration system in fluid communication with the liquid distribution system to receive the CO2 capture solution, the regeneration system configured to regenerate the CO2 capture solution and form a CO2-lean liquid for return to the at least one gas-liquid contactor. The regeneration system is configured to provide a CO2 product stream for output or use.

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