Gas-liquid contactor with packing for capturing carbon dioxide

Abstract

Dilution to carbon dioxide (CO 2 ) is captured by packing 2 at least one panel comprising a mesh material defining a gas passageway having a first dimension defined along a first direction and a second dimension defined along a second direction different from the first direction, the gas passageway extending from a dilution gas source to a CO2 source in the second direction; 2 Accepts a flow of contained gas and CO 2 The flow of contained gas is passed through the mesh material. 2 It is adapted to be contacted with a capture solution.

Description

[Technical field]

[0001] This disclosure describes systems and methods for capturing CO2. [Background technology]

[0002] Global warming resulting from rising atmospheric CO2 concentrations is considered an imminent threat to society. According to the National Oceanic and Atmospheric Administration (NOAA) (Linsday, 2020), Earth's atmospheric carbon dioxide reached 409.8 ± 0.1 ppm in 2019, the highest level on record. This was an increase of 2.5 ± 0.1 ppm from 2018, and the same increase from 2017 to 2018. In the 1960s, the global rate of increase of atmospheric carbon dioxide was roughly 0.6 ± 0.1 ppm per year. However, from 2009 to 2018, the rate of increase was 2.3 ppm per year. Techniques to remove carbon dioxide emissions from the atmosphere have become an important area of ​​research.

[0003] Low-carbon, carbon-neutral, or carbon-negative consumer goods and services are also becoming important in the global market. It is also important to minimize the energy and environmental impacts of the production, use, and disposal of industrial products, from basic commodities such as metals and chemicals to sophisticated end-use products such as electric vehicles, solar panels, and wind turbines. Renewable energy from its many sources is a great way to power, heat, and fuel for our habitat. From hydro to solar to biomass, each type of renewable energy contributes in a different way. The use of renewable energy in combination with reducing carbon emissions and reducing carbon emissions in the production of consumer goods and services can create economy-wide reductions in greenhouse gas (GHG) emissions. These improvements can be further enhanced by the development of new material and process technologies. Carbon removal is one of many technologies to reduce GHG emissions, including point source and direct air capture (DAC) processes.

[0004] Many technologies designed for CO2 capture from point sources, such as flue gas from industrial facilities, are generally ineffective at capturing CO2 from the atmosphere due to the extremely low CO2 concentrations and the large volumes of air that need to be processed. In recent years, progress has been made in finding technologies better adapted to capture CO2 directly from the atmosphere, and various DAC technologies have been described in the technical and patent literature. Some of these DAC systems use solid sorbents, where an activator is attached to a substrate. These DAC systems typically use a cyclic adsorption-desorption process, where the solid sorbent is saturated with CO2 and then regenerated using moisture or heat swings to release CO2. Although solid sorbent DAC systems can have high cyclic yields, large-scale deployment is difficult due to the maintenance requirements that are inherent to batch processes.

[0005] Other DAC systems use liquid sorbents (sometimes referred to as solvents) to capture CO2 from the atmosphere. An example of such a gas-liquid contacting system is based on a cooling tower design, where a fan is used to draw air over a large surface area packing wetted with a solution containing the liquid sorbent. The CO2 in the air reacts with the liquid sorbent. The strong solution is further processed downstream to regenerate the weak solution and to release a stream of concentrated CO2. DAC systems designed based on cooling towers are advantageous because they use some commercially available equipment and can operate more efficiently in certain environments than others. It is desirable for DAC systems to be easily maintainable and operationally flexible. Summary of the Invention [Means for solving the problem]

[0006] In an exemplary implementation, a packing for capturing carbon dioxide (CO2) from dilution comprises at least one panel, the at least one panel comprising a mesh material configured to be wetted by a CO2 capture solution, and defining a gas passage having a first dimension defined along a first direction and a second dimension defined along a second direction different from the first direction, the gas passage configured to receive a flow of CO2-containing gas from a dilution gas source in the second direction and to contact the CO2-containing gas flow with the CO2 capture solution at the mesh material.

[0007] In an aspect combinable with the implementation example, the at least one panel comprises a plurality of panels, adjacent panels of the plurality of panels being spaced apart from one another in a first direction and defining respective gas passages between each of the adjacent panels, each of the respective gas passages being defined by a respective first dimension.

[0008] In another aspect that may be combined with any of the previous aspects, each of the adjacent panels defines a planar surface, and the planar surfaces of the adjacent panels are parallel to one another.

[0009] In another aspect that may be combined with any of the preceding aspects, at least one of the adjacent panels includes a plurality of planar portions and a plurality of protruding portions, the plurality of planar portions defining parallel planes, and the plurality of protruding portions extending outwardly from the parallel planes in a first direction into a respective gas passage.

[0010] In another aspect which may be combined with any of the previous aspects, each of the adjacent panels has the same shape.

[0011] In another embodiment that may be combined with any of the preceding embodiments, the gas passage is colinear with the second direction of flow of the CO2-containing gas.

[0012] In another embodiment that may be combined with any of the preceding embodiments, the at least one panel is a single panel, and the mesh material comprises a continuous sheet of mesh material.

[0013] In another embodiment that may be combined with any of the preceding embodiments, the continuous sheet of mesh material includes a plurality of panel sections spaced apart from one another in a first direction to define a gas passageway.

[0014] In another aspect combinable with any of the preceding aspects, the at least one panel comprises a plurality of panels spaced apart from one another in a first direction, the plurality of panels defining a plurality of gas passages between adjacent panels of the plurality of panels, at least one gas passage of the plurality of gas passages defined by a first dimension comprising a first width, and at least one other gas passage of the plurality of gas passages defined by a first dimension comprising a second width different from the first width.

[0015] In another embodiment that may be combined with any of the preceding embodiments, the gas passage defines a gas passage cross-sectional shape in a plane perpendicular to the second dimension, the gas passage cross-sectional shape being at least one of a rectangle, a triangle, or a diamond.

[0016] In another embodiment that may be combined with any of the preceding embodiments, the first dimension is 6 inches or less.

[0017] In another embodiment that can be combined with any of the preceding embodiments, the CO2 capture solution is at least one of a hydroxide solution, a bicarbonate / carbonate solution, or an amine solution.

[0018] In another aspect that may be combined with any of the preceding aspects, the mesh material comprises a plurality of fibers that define a plurality of mesh apertures, and the mesh material is configured to be wetted with the CO2 capture solution to cause the CO2 capture solution to span at least a portion of the mesh apertures of the wetted mesh material and define a gas-liquid interface.

[0019] In another embodiment that may be combined with any of the preceding embodiments, the gas-liquid interface comprises a first side disposed on a first side of the mesh material and a second side disposed on a second side of the mesh material opposite the first side of the mesh material.

[0020] In another embodiment that may be combined with any of the preceding embodiments, the first side of the gas-liquid interface and the second side of the gas-liquid interface collectively define a total reactive gas-liquid interface area that is greater than a surface area of ​​a corresponding fiber of the mesh material.

[0021] In another embodiment that may be combined with any of the preceding embodiments, the wetting fraction of the mesh material is greater than 100%.

[0022] In another embodiment that may be combined with any of the preceding embodiments, at least one panel has an upright orientation and the second dimension is less than three orders of magnitude greater than the first dimension.

[0023] In another aspect that may be combined with any of the preceding aspects, the mesh material comprises a hydrophilic material.

[0024] In another aspect that may be combined with any of the preceding aspects, the hydrophilic material is a hydrophilic coating disposed on at least a portion of the mesh material.

[0025] In another aspect that may be combined with any of the preceding aspects, the hydrophilic material comprises at least one of a nonwoven material or an organic material.

[0026] In another embodiment that may be combined with any of the preceding embodiments, the organic material comprises at least one of burlap, hemp, or cellulose.

[0027] In another aspect that may be combined with any of the preceding aspects, the mesh material comprises a hydrophobic material.

[0028] In another aspect that may be combined with any of the preceding aspects, the hydrophobic material is a hydrophobic coating disposed on at least a portion of the mesh material.

[0029] In another aspect that may be combined with any of the preceding aspects, the mesh material comprises a plurality of fibers having a surface texture.

[0030] In another embodiment that may be combined with any of the preceding embodiments, the mesh material comprises a plurality of fibers, each having a diameter ranging from 0.0001 mm to 10 mm.

[0031] In another embodiment that may be combined with any of the preceding embodiments, the mesh material comprises a plurality of mesh perforations, the plurality of mesh perforations having one or more shapes comprising at least one of a hexagon, a rectangle, or a circle.

[0032] In another aspect that may be combined with any of the preceding aspects, the mesh material is shaped to form a plurality of imprinted textures comprising at least one of rounded protrusions, ridges, corrugations, or herringbones.

[0033] In another implementation, a gas-liquid contactor for capturing carbon dioxide (CO2) from a dilution gas source comprises a housing at least partially enclosing a plenum having an inlet and an outlet; at least one packing supported in the housing downstream of the inlet, the at least one packing comprising at least one panel comprising a mesh material and defining a gas passageway having a first dimension defined along a first direction and a second dimension defined along a second direction different from the first direction; a liquid distribution system configured to wet the mesh material with a CO2 capture solution, the liquid distribution system comprising one or more liquid reservoirs configured to hold the CO2 capture solution received from the mesh material; and a gas transfer device configured to flow the CO2-containing gas from the dilution gas source through the gas passageway in the second direction to contact the CO2-containing gas with the CO2 capture solution at the wetted mesh material.

[0034] An embodiment that can be combined with the implementation further includes a drift eliminator coupled to the housing and positioned downstream of the at least one packing.

[0035] In another embodiment that may be combined with any of the preceding embodiments, the gas moving device is a fan disposed downstream of the at least one packing at the outlet, the fan rotatable about a fan axis to draw the CO2-containing gas in a second direction through the gas passage to the inlet.

[0036] In another embodiment that may be combined with any of the previous embodiments, the liquid distribution system is configured to wet the mesh material, the wetted mesh material forming a liquid film of the CO2 capture solution on the mesh material.

[0037] In another embodiment that can be combined with any of the preceding embodiments, the liquid distribution system is configured to flow the CO2 capture solution at a solution flow rate ranging from 1 L / min to 4 L / min.

[0038] Another aspect that may be combined with any of the previous aspects further includes a structural support supported by the housing and configured to support at least one packing, the structural support comprising one or more support bars attached to the one or more support beams.

[0039] In another embodiment that may be combined with any of the preceding embodiments, the mesh material is fixedly attached to the one or more support bars by at least one of stitching, tensioning, or fasteners.

[0040] In another embodiment that may be combined with any of the preceding embodiments, the liquid distribution system includes one or more distribution facilitation devices configured to provide the CO2 capture solution to at least a portion of the mesh material.

[0041] In another aspect that may be combined with any of the preceding aspects, the one or more dispense facilitation devices comprise at least one of a liquid dispensing wand or a liquid dispensing spacer.

[0042] In another aspect that may be combined with any of the preceding aspects, one or more of the liquid dispensing spacers comprises at least one tube having a tapered end.

[0043] In another aspect that may be combined with any of the preceding aspects, the liquid dispensing wand includes a plurality of channels operable to flow the capture solution.

[0044] In another aspect that may be combined with any of the preceding aspects, the one or more liquid dispensing spacers are pressed against the one or more liquid dispensing rods to form at least a portion of the upper reservoir.

[0045] In another embodiment that may be combined with any of the previous embodiments, the liquid dispensing rod(s) and the liquid dispensing spacer(s) are integrally formed with a mesh material.

[0046] In another embodiment that may be combined with any of the preceding embodiments, the one or more liquid dispensing rods, the one or more liquid dispensing spacers, and at least one panel comprise a fiberglass core at least partially covered with a PVC covering.

[0047] In another aspect that may be combined with any of the preceding aspects, a first support bar of the one or more support bars is configured to interlock with a second support bar of the one or more support bars.

[0048] In another embodiment that may be combined with any of the preceding embodiments, the one or more support bars have a cross-section that is C-shaped or arcuate.

[0049] In another embodiment that may be combined with any of the preceding embodiments, the one or more support bars each have a thickness that tapers from the first end of the respective support bar to the second end of the respective support bar.

[0050] In another aspect that may be combined with any of the preceding aspects, the one or more liquid reservoirs include at least one upper liquid reservoir positioned above the at least one panel and at least one bottom liquid reservoir positioned below the at least one panel, and the liquid distribution system is configured to flow at least a portion of the CO2 capture solution from the at least one bottom liquid reservoir to the at least one upper liquid reservoir.

[0051] In another embodiment that may be combined with any of the preceding embodiments, the gas-liquid contactor is configured to operate as part of a cooling tower system, a direct air capture air contacting system, or a combination thereof.

[0052] Another embodiment combinable with any of the previous embodiments further includes a structural support supported by the housing and configured to support at least one packing, the structural support comprising one or more support bars, a first subset of bars of the one or more support bars being offset from a second subset of bars of the one or more support bars, the second subset of bars being spaced apart from the first subset of bars in a direction perpendicular to the first and second dimensions, the mesh material comprising a continuous sheet of mesh material tensioned around the first subset of bars and the second subset of bars to form a plurality of panel sections, the plurality of panel sections extending between the spaced apart bars of the first subset of bars and the second subset of bars.

[0053] In another aspect that may be combined with any of the previous aspects, adjacent panel sections of the plurality of panel sections are spaced apart from one another in a first direction to define a gas passage, the first dimension decreasing in a direction parallel to the distance between the first subset of bars and the second subset of bars.

[0054] In another aspect that may be combined with any of the previous aspects, adjacent panel sections of the plurality of panel sections have a non-parallel orientation relative to one another.

[0055] Another embodiment that can be combined with any of the previous embodiments further includes a structural support supported by the housing and configured to support at least one packing, the structural support comprising one or more support bars, the mesh material being suspended from the one or more support bars.

[0056] Another embodiment that can be combined with any of the previous embodiments further includes one or more spacers, each of the one or more spacers being interposed between adjacent support bars of the one or more support bars.

[0057] In another embodiment that may be combined with any of the preceding embodiments, the one or more spacers comprise one or more distributed spacers.

[0058] Another aspect that may be combined with any of the preceding aspects further comprises one or more dispensing facilitation devices.

[0059] In another aspect that may be combined with any of the preceding aspects, the one or more dispense facilitation devices comprise at least one of a dispense support bar or a dispense spacer.

[0060] In another embodiment that may be combined with any of the preceding embodiments, the one or more spacers comprise at least one tube having a tapered end.

[0061] In another embodiment that may be combined with any of the preceding embodiments, the liquid distribution system further comprises one or more flow devices configured to flow the CO2 capture solution across the at least one packing, the one or more flow devices comprising at least one of a nozzle, a spray atomizer, or a liquid distribution wand.

[0062] In another embodiment combinable with any of the preceding embodiments, the at least one packing comprises two packings spaced apart from one another laterally within the housing, and the gas moving device comprises a fan disposed laterally between the two packings and downstream of the two packings at the outlet, the fan rotatable about an upright fan axis to draw CO2-containing gas from the dilution gas source through the two packings and to expel CO2-lean gas through the outlet.

[0063] In another embodiment that may be combined with any of the preceding embodiments, at least one panel defines a planar surface having a vector perpendicular to the planar surface, the vector having a horizontal orientation.

[0064] In another embodiment that may be combined with any of the preceding embodiments, at least one panel has an upright orientation and includes a leading edge defined relative to the flow of the CO2-containing gas, the leading edge being inclined in the direction of the flow of the CO2-containing gas and defining an angle relative to the vertical axis.

[0065] In another implementation, a method for capturing CO2 from a CO2-containing gas includes wetting at least a portion of spaced apart mesh panels with a CO2 capture solution to flow the CO2 capture solution along the spaced apart mesh panels, flowing the CO2-containing gas along a gas passage defined between the spaced apart mesh panels, reacting the CO2-containing gas with the CO2 capture solution in the wetted spaced apart mesh panels, and absorbing at least a portion of the CO2 in the CO2-containing gas with the CO2 capture solution.

[0066] In an aspect that can be combined with the implementation, flowing the CO2-containing gas along the gas passage includes flowing the CO2-containing gas linearly through the gas passage along a first dimension of the gas passage.

[0067] In another aspect combinable with any of the preceding aspects, wetting at least a portion of the spaced apart mesh panels with the CO2 capturing solution includes flowing the CO2 capturing solution across the spaced apart mesh panels in a first direction, and flowing the CO2-containing gas along the gas passage includes flowing the CO2-containing gas along the gas passage in a second direction transverse to the first direction.

[0068] In another embodiment that can be combined with any of the preceding embodiments, the second direction is countercurrent to the first direction.

[0069] In another aspect that may be combined with any of the preceding aspects, wetting at least a portion of the spaced apart mesh panels with a CO2 capturing solution includes flowing the CO2 capturing solution at a flow rate ranging from 1 L / min to 4 L / min.

[0070] In another aspect that may be combined with any of the preceding aspects, wetting at least a portion of the spaced apart mesh panels with a CO2-capturing solution includes saturating at least a portion of the spaced apart mesh panels with the CO2-capturing solution and flowing the CO2-capturing solution along the saturated at least a portion of the spaced apart mesh panels to form one or more serpentine flows.

[0071] In other aspects that may be combined with any of the preceding aspects, wetting at least a portion of the spaced apart mesh panels with the CO2-capturing solution includes forming a liquid film of the CO2-capturing solution along at least a portion of the spaced apart mesh panels.

[0072] In another aspect that may be combined with any of the preceding aspects, flowing the CO2-containing gas along the gas passage includes rotating one or more fans to draw the CO2-containing gas along the gas passage.

[0073] Another embodiment that can be combined with any of the previous embodiments further includes collecting at least a portion of the CO2 capture solution in one or more bottom reservoirs and flowing at least a portion of the CO2 capture solution from the one or more bottom reservoirs to one or more upper reservoirs.

[0074] Another embodiment that can be combined with any of the previous embodiments further includes reacting a CO2-containing gas with a CO2 capture solution to form a CO2-lean gas and a CO2-rich capture solution, and releasing the CO2-lean gas.

[0075] Another embodiment that can be combined with any of the previous embodiments further includes flowing the CO2 lean gas through one or more drift eliminators.

[0076] Another embodiment that can be combined with any of the previous embodiments further includes, after the step of flowing the CO2-containing gas along the gas passages defined between the spaced apart mesh panels, flowing the CO2-lean gas through an open plenum.

[0077] In another aspect that may be combined with any of the preceding aspects, wetting at least a portion of the spaced apart mesh panels with the CO2-capturing solution includes bridging the CO2-capturing solution across mesh perforations of the spaced apart mesh panels to define a gas-liquid interface.

[0078] In another embodiment that may be combined with any of the preceding embodiments, bridging the CO2 capture solution across the mesh perforations includes forming a gas-liquid interface on both opposing sides of each spaced apart mesh.

[0079] In another aspect that may be combined with any of the preceding aspects, spanning the mesh perforations includes wetting hydrophilic mesh fibers of the spaced apart mesh panels with the CO2 capture solution, the hydrophilic mesh fibers defining the mesh perforations.

[0080] In another aspect that may be combined with any of the preceding aspects, wetting at least a portion of the spaced apart mesh panels with the CO2 capture solution includes wetting an outer surface of the hydrophilic mesh fibers of the spaced apart mesh panels with the CO2 capture solution.

[0081] In another aspect that may be combined with any of the preceding aspects, wetting the exterior surface of the hydrophilic mesh fibers includes flowing a CO2 capture solution along the exterior surface of the hydrophilic mesh fibers.

[0082] In another aspect that may be combined with any of the preceding aspects, wetting the exterior surface of the hydrophilic mesh fibers includes wetting the hydrophilic mesh fibers with the CO2 capture solution beyond a saturation level of the hydrophilic mesh fibers to form a film of the CO2 capture solution that extends across mesh pores defined by the hydrophilic mesh fibers.

[0083] In another aspect that may be combined with any of the preceding aspects, wetting at least a portion of the spaced apart mesh panels with the CO2 capture solution includes conditioning at least a portion of the spaced apart mesh panels by forming a solid precipitate on mesh fibers of the spaced apart mesh panels.

[0084] In another implementation, a method for capturing CO2 from a dilute source includes providing a capture solution from one or more upper liquid reservoirs using a liquid distribution system to one or more sections of packing, each of which comprises one or more mesh sheets; distributing the capture solution over at least a portion of the packing; operating a fan to draw a CO2-containing gas through the mesh packing; operating the fan to flow the CO2-containing gas in the same straight line through one or more gas passages defined by the one or more mesh sheets; reacting the CO2-containing gas with the capture solution to form a CO2-lean gas and a CO2-rich capture solution; collecting the CO2-rich capture solution in one or more bottom liquid reservoirs; and releasing the CO2-lean gas.

[0085] A combinable embodiment of the implementation further includes flowing the CO2 lean gas through one or more drift eliminators.

[0086] Another embodiment that can be combined with any of the previous embodiments further includes flowing the CO2 lean gas through the open plenum area.

[0087] In another aspect that may be combined with any of the preceding aspects, providing the capture solution to one or more areas of the packing includes providing the capture solution via one or more liquid distribution facilitation devices.

[0088] In another aspect that may be combined with any of the preceding aspects, the step of providing the capture solution using one or more liquid dispensing facilitation devices includes providing the capture solution using at least one of a liquid dispensing wand or a liquid dispensing spacer.

[0089] In another implementation, a method of configuring a cooling tower to capture CO2 from a dilute source of CO2 gas includes supporting at least one mesh packing within the cooling tower between an inlet and an outlet of the cooling tower, and orienting the at least one mesh packing within the cooling tower to form an unobstructed flow path between a gas passageway of the at least one mesh packing and the inlet and outlet.

[0090] A possible embodiment of the present invention further includes removing existing packing from within the cooling tower prior to supporting the at least one mesh packing within the cooling tower.

[0091] 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 the drawings]

[0092] [Figure 1] FIG. 2 is a schematic diagram from an elevation of an exemplary gas-liquid contactor. [Diagram 2] FIG. 1 is a schematic diagram of an exemplary countercurrent gas-liquid contactor. [Diagram 3] FIG. 1 is a schematic diagram of an exemplary cross-flow gas-liquid contactor. [Figure 4] FIG. 1 is a schematic diagram from an elevation of an exemplary mesh packing and support system. [Diagram 5] 1A-1C are elevational orthogonal views of an exemplary mesh packing and support system; [Figure 6] FIG. 1 is a perspective view of an exemplary mesh packing including mesh panels positioned substantially horizontally. [Figure 7] FIG. 13 is a diagram of an example bar design for a structural support system. [Figure 8]Figure 8A is a schematic diagram from a side elevational view of an example mesh packing and support system, and Figures 8B-8J are diagrams of various arrangements of gas passageways for the mesh packing and support system of Figure 8A. [Figure 9] FIG. 1 is a schematic diagram of an exemplary mesh packing and support system from a front elevation view. [Figure 10] FIG. 1 is a schematic diagram of an exemplary mesh packing and support system from an end view. [Figure 11] FIG. 1 is a schematic diagram of an exemplary mesh packing support and liquid distribution system from a front elevation view. [Figure 12] 1 is a schematic diagram of an exemplary mesh packing support and liquid distribution system from a plan view. FIG. [Figure 13] FIG. 1 illustrates an exemplary integrated structural support system. [Figure 14] Figure 14A is a diagram of an exemplary hydrophobic mesh sheet, and Figures 14B and 14C are diagrams of a liquid distribution technique for the example hydrophobic mesh sheet of Figure 14A. [Figure 15] Figures 15A and 15B are diagrams of an exemplary hydrophilic mesh sheet and Figure 15C is a diagram of an exemplary liquid dispensing technique for the example hydrophilic mesh sheet of Figures 15A and 15B. [Figure 16A] FIG. 1 is a front view of a test prototype of an exemplary mesh packing and support system. [Figure 16B] FIG. 1 is a side view of a test prototype of an exemplary mesh packing and support system. [Figure 16C] FIG. 1 is a plan view of a test prototype of an exemplary mesh packing and support system. [Figure 17] 1 is a graph of mass transfer versus air velocity for various adsorbent loadings. [Figure 18A] FIG. 13 is an example of a molded mesh comprising a mesh sheet with an imprinted texture. [Figure 18B]FIG. 13 is an example of a molded mesh comprising a mesh sheet with an imprinted texture. [Figure 19] 13A-13C are diagrams of example flow patterns of capture solution at varying solution flow rates in a mesh sheet. [Figure 20] FIG. 1 is a schematic diagram from an elevation of an exemplary mesh packing and support system. [Figure 21] FIG. 1 is a schematic diagram of an exemplary gas-liquid contactor for use in a direct air capture (DAC) facility. [Figure 22] FIG. 2 is a schematic diagram from an elevation of an exemplary gas-liquid contactor. [Figure 23] 1 is a schematic diagram of an exemplary gas-liquid contactor from a top view. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0093] The present disclosure relates to systems and methods for direct air capture (DAC) of CO2 from air or other dilute gas sources containing CO2 using a gas-liquid contactor containing mesh packing. The CO2 concentration in dilute sources such as air (about 400-420 ppm or 0.04-0.042% v / v) is much lower than the CO2 concentration in point sources such as flue gas (about 5-15% v / v). Mass transfer kinetics favor CO2 capture from point sources. Thus, design considerations for the CO2 capture subsystem and capture solution regeneration subsystem are different for dilute sources when compared to point sources. Although the present disclosure relates to the capture of CO2 from air or other dilute gas sources containing CO2, it will be understood that the systems, methods, and disclosures herein may be used to capture CO2 from more concentrated sources of CO2 that have or are accompanied by a dilute gas source, such as flue gas mixed with air.

[0094] Commercially available packings, such as those used in cooling towers or flue gas scrubbers, have been used in DAC applications. However, these commercially available packings are not specifically designed for the mass transfer requirements of dilute CO2 in DAC applications and are therefore not optimized for DAC applications. For example, commercially available packings from the cooling tower industry are designed for use with water and to maximize heat transfer without much consideration for mass transfer, which is important for DAC systems. In contrast to commercially available packings from the cooling tower industry, the mesh packings disclosed herein can be used to facilitate mass transfer of CO2 from a gaseous source (e.g., air) containing CO2 to a capture solvent that wets the mesh packing.

[0095] Commercially available cooling tower packings are also specially designed to achieve sufficient wetting under high liquid-load conditions while air is pulled through the packing obstruction. Thereby, cooling tower packings have shown lower wetting efficiency for low liquid-load speeds that are often of interest for DAC applications. At low liquid-load speeds, the capture solution may tend to trickle as it travels down the cooling tower packing and may form passages. The low wetting efficiency caused by the trickle of capture solution may result in unnecessarily low mass transfer due to reduced interfacial area per unit packing area (resulting in low CO2 uptake) and higher pumping rates required to increase the liquid sorbent flow, ultimately requiring a large air contactor footprint.

[0096] Packings made for conventional "packing towers," "packing columns," and / or flue gas scrubbers in chemical processing plants are designed for much higher CO2 concentrations, roughly 10-15% v / v, and for smaller gas volumetric flow rates per scrubber column, compared to DAC applications such as those disclosed herein. Thus, significantly smaller volumes of gas are required for processing in these conventional packed towers to capture equivalent amounts of CO2 from air using DAC. Also, conventional packed towers are typically used in a countercurrent (rather than crosscurrent) orientation, since this is the flow orientation with the greatest mass transfer efficiency, whereas countercurrent scrub column designs are not suitable for DAC, since air flow rates are primarily constrained by the injection point. The kinetics of capture in a flue gas scrubber or high concentration chemical absorber are generally more favorable compared to those associated with dilute CO2 concentrations, as in DAC systems such as those disclosed herein.

[0097] While both point source capture and DAC technologies capture CO2 from gas streams, the process designs for both technologies are different due to their different feedstock and process conditions. However, there are ways in which the present disclosure can be used to retrofit, modify, or redesign existing cooling towers to facilitate at least a portion of the CO2 capture capacity found in existing DAC systems. Furthermore, when incorporated into a DAC system, the present disclosure can further improve at least one of capture efficiency, pressure drop, capital investment, operational expenses, and / or simplify and reduce maintenance and installation.

[0098] The gas-liquid contactor systems and methods described herein may include a mesh packing coupled to the structural support, the liquid distribution system, and one or more liquid collection systems. In some cases, the mesh packing may comprise one or more mesh screens positioned adjacent to one another. The mesh packing material, design, and configuration may enable highly efficient mass transfer of CO2 into solution, lower pressure drop and higher air velocity over the Air Travel Depth (ATD), and lower total liquid flow rates. These features, individually and additively, produce several advantages in performance, maintenance, and overall economics of capturing CO2 from a dilution gas source.

[0099] The mesh packing design and operating characteristics described herein can provide overall economic benefits to the gas-liquid contactor DAC system, either individually or when combined with liquid distribution embodiments, such as those according to the present disclosure. For example, for a given CO2 capture rate, the mesh packing design and additional features described herein can help reduce the air advance depth (ATD) and can help reduce the overall footprint of the DAC system, including structural requirements and critical structural materials, such as concrete requirements, all of which result in lower capital costs for the gas-liquid contactor system. Also, the sorbent pumping system and energy demands using the mesh packing design and additional features described herein are reduced due to lower flow rates. This is achieved in part because the mesh packing and mode of operation can facilitate a large contact area of ​​wetted interfaces that are continuously replenished through uniform solution distribution throughout the mesh packing. The design and materials used in manufacturing the mesh packing can improve wettability over conventional packing.

[0100] In addition to the reduction in overall gas-liquid contactor material and footprint required, as discussed above, another advantage of mesh packing over commercially available packing is the smaller packing volume and reduced packing material required, which in turn reduces the pressure drop across the ATD and consequently reduces the fan power required to operate the system.

[0101] Because the gas-liquid contactor is the largest system in large-scale DAC applications, any improvement in performance, energy efficiency, or reduction in materials and footprint has a significant and compelling impact on the economics of the entire DAC facility.

[0102] Maintenance advantages can also be realized with the present disclosure. The sewn-in mesh material can be easily replaced with new mesh material if a portion of the mesh material is damaged. The mesh material can be removed from the bar when it is disconnected from the support beam. In an embodiment, the use of mesh material with commercially standardized thickness and dimensions (no special modifications required) can result in a low-cost material that is easily sourced, convenient to replace and maintain, which will result in reduced associated air contactor maintenance / operational costs and downtime.

[0103] The methods and systems described herein can also be used in systems that are constructed or modified for CO2 capture and operated with various liquid solutions that contain CO2 capture sorbents. The methods and systems can also be used by retrofitting existing cooling tower systems. The mesh packing is compatible for use in existing DAC or cooling tower systems between their associated components, including drift eliminators, fans or blowers, housings, frames, CO2 capture solution reservoirs and / or distribution systems, gas inlet and outlet areas, etc.

[0104] Mesh packing can be installed in existing contactor housings without requiring significant redesign. Mesh packing can also be installed in contactor housings designed to operate without the existing structural elements of the cooling tower. Mesh packing can be assembled inside and outside of the cooling tower. Mesh packing can be installed in the cooling tower using methods similar to any installation methods for commercially available packings, such as from the top or one side of the cooling tower. Mesh packing includes low-cost, lightweight woven and / or sewn mesh material with long-lasting structural integrity.

[0105] In some implementations, the gas-liquid contactor can be an air contactor having one or more cells, including one or more fans, pumps, sumps, drift eliminators, packings, housings, structural parts, control systems, and similar components based on the cooling tower equipment modified. In an embodiment, the gas-liquid contactor can be a dual cell cross-flow contactor. In an embodiment, the gas-liquid contactor can be an existing cooling tower system having one or more of a cross-flow or counter-flow configuration, retrofitted with the disclosed mesh packing.

[0106] In some implementations, the gas-liquid contactor comprises one or more upper liquid reservoirs, a structural support frame, one or more plenums, one or more bottom liquid collection reservoirs, a housing, one or more liquid distribution systems (coupled to one or more pumps, valves, and nozzles), one or more fans and baffles, packing, and drift eliminator components.

[0107] In some implementations, the mesh packing is coupled to one or more liquid distribution facilitating devices. In some cases, these devices may comprise existing support parts or new components that facilitate or assist in uniform distribution of the liquid solution into the mesh material. In some implementations, the liquid distribution facilitating device comprises one or more existing upper support bars, etc., that are modified (e.g., made to be hollow, with holes, or with other similar internal or external features that allow liquid distribution) to convey liquid along the length of the support bars to the mesh material in addition to providing the structural function of support and / or tensioning the mesh material. Another example of a liquid distribution facilitating device is a distribution spacer that comprises one or more upper spacers that are modified (e.g., with holes, or made from a rigid mesh material or a material with similar features that allow liquid distribution) to convey liquid along the length of the spacer to the membrane material in addition to providing the structural function of the maintenance space between the support bars.

[0108] In some implementations, the gas-liquid contactor includes mesh packing (or multiple mesh packing sections). In some embodiments, the mesh packing consists of a single continuous sheet of mesh material that is sewn through the structural components to create the packing, or the packing can consist of one or more individual panels or sheets of mesh material that are joined to the structural components to create the packing. The mesh packing is configured and positioned to facilitate mass transfer between the gas and liquid flows moving through the gas-liquid contactor.

[0109] In some implementations, the gas-liquid contactor uses a liquid distribution system similar to cooling tower or DAC systems known today, such as an upper sump and nozzle distribution system or a pressurized piping blown nozzle distribution system.

[0110] The methods and systems described in this disclosure can enable the concept of net-zero emissions through the deployment of large-scale DAC plants associated with various downstream processes, including, for example, sequestration and / or enhanced oil recovery (EOR) applications, as well as the production of synthetic products including hydrocarbons, fuels, plastics, chemicals, and the like.

[0111] To optimize the techno-economics of DAC-specific applications, the low concentration of CO2 in the atmosphere drives the design of the packing towards high air flow rates and low pressure drop through the packing, while providing a large gas-liquid interfacial area at low solution flow rates (compared to conventional cooling towers with high solution flow rates and therefore higher solution pumping and distribution costs). In some implementations, the reduction in solution flow rate can change the overall flow pattern from film flow to trickle flow, which can reduce the gas-liquid interfacial area available for mass exchange from the CO2-laden air to the CO2 capture solution.

[0112] The flow rate at which the transition in the flow pattern occurs depends on many factors, including the free energy and geometry of the solid surfaces of the packing, as well as the density, viscosity, and surface tension of the CO2 capture solution. These properties of the CO2 capture solution differ from those of water, a typical liquid in cooling tower applications, due to the presence of concentrated sorbents (e.g., KOH or NaOH, carbonate / bicarbonate chemistries, liquid amines, capture or mass transfer enhancing additives, etc.) in the CO2 capture solution.

[0113] In some cases, the mesh material is configured to not only reduce the overall weight of the system, but also to reduce the pressure drop across the seat, which in some cases allows for higher volumetric airflow and higher air velocity, which further improves overall efficiency, economy, and energy savings.

[0114] In some implementations, the mesh packing may consist of one or more sheets of mesh material arranged to create multiple gas passageways for a large volume of gas (e.g., air or other gases containing a dilute concentration of CO2) to travel in the same linear direction as the mesh sheet surface at high velocity and low pressure drop. In some cases, the mesh packing may comprise one or more screens positioned adjacent to one another.

[0115] In some implementations, the mesh packing is a structured (e.g., not loose) packing, where the pieces or sheets of mesh material that comprise the structured mesh packing are structured themselves, have structure provided through the use of structural components such as support rods, beams, etc., or a combination thereof.

[0116] In some implementations, the mesh material is composed of multiple fibers woven together or connected to form a mesh with multiple openings or pores. The geometry of this structure can be tailored to minimize the amount of material required to facilitate the formation of a continuous or uniform liquid film surface with a given CO2 capture solution. In some implementations, the technique for forming the interface area is capillary bridging, where the mesh fiber diameter, surface energy of the fiber material as well as fiber spacing (pore size) can be optimized to allow for a minimum mass of mesh material while still providing sufficient conditions for a given CO2 capture solution to bridge the mesh pores / openings, create and maintain a continuous film of liquid across the mesh pores, and create a large interface area for gas-liquid contact.

[0117] In some implementations, the properties of a particular sorbent solution, such as surface tension, viscosity, density, etc., can dictate the maximum mesh pore size above which the solution can no longer span the pore openings and trickle patterns will dominate the resulting reduction in sorbent hold-up. Thus, in some implementations, the selection of mesh material and design (including pore size) must take into account, at least in part, the type of capture solution being considered.

[0118] In some implementations, the design and / or operation of the mesh packing and gas-liquid contactor may incorporate features to better enhance and create an optimal interfacial surface area for capture of CO given the particular properties of the capture solution. For example, this can be done by adjusting mesh packing material properties, fiber diameter, pore size, and / or liquid sorbent flow rate to optimize system performance, taking into account the particular liquid solution properties, including but not limited to temperature, pH, viscosity, and / or density.

[0119] Furthermore, the overall wettability is determined in part by the physical wettability of the mesh material, which is directly related to the surface energy and is determined in part by the completeness of coverage as the liquid travels from one end of the mesh material to the other. The path that the liquid takes through the mesh material is determined in part by the shape, surface structure, and surface energy of the mesh material.

[0120] In some implementations, the fiber thickness of the mesh material can range between 0.01 mm and 10.0 mm and can be optimized to ensure that the surface tension of the adsorbent facilitates complete wrapping of the adsorbent around each individual fiber, and in some cases, the fiber thickness is minimized to minimize the amount of mesh material while maintaining structural integrity and durability.

[0121] In some implementations, the fiber spacing of the mesh material creates pores (openings) with a size / width that ranges between 0.1 mm and 30.0 mm. In some cases, the fiber spacing is optimized to work with the surface tension of the sorbent to pull the sorbent across the gaps / pores, facilitating the use of the sorbent for the formation of the reactive interface / surface instead of the mesh material. In one embodiment, a relationship is provided between the size of the pores and the formation of the liquid film. For example, the size of the pores (openings) can be maximized while still facilitating the formation and bridging of a complete liquid film across the opening. Optimizing the size of the pores minimizes the volume and mass of the mesh material while maintaining a particular reactive interface area.

[0122] In some implementations, the mesh material can be made from fibers that can be straight or wavy with smooth or rough surfaces. Sheets of mesh material can be fabricated by weaving weft and warp wires with the same or different diameters and thicknesses. Continuous wires that are not pre-shrunk or shaped can be used. The type of weaving pattern used to form the mesh material can include weaves with squares or rectangles, twill, basket, herringbone, sheets with mesh pores (or openings) that have hexagonal (honeycomb), square, rectangular, or circular shapes, or combinations thereof. The choice of mesh shape can affect the open surface area, material strength, and how much material needs to be used to form the mesh.

[0123] The mesh packing can be made using a variety of materials and can rely on either hydrophobic or hydrophilic techniques (described in detail herein) to wet the surface depending on the intended application and design. In some embodiments, the mesh material is selected to be compatible with CO2 capture solutions, such as high pH solutions and / or hydroxide solutions such as KOH, NaOH, etc.

[0124] In some implementations, the sheet of mesh material may include portions made from or coated with one or more materials. In some implementations, the sheet of mesh material may include two or more groups of fibers, each group of fibers made from a different material, and these groups of fibers may be woven or connected together to form a mixed mesh material for use in one or more sheets in the packing. In some cases, the fibers are made from mixed fiber materials.

[0125] In some hydrophobic implementations, the sheet of mesh material can be made from different types of materials, such as plastic, metal, polymeric composites, or combinations thereof. In some cases, the plastic sheet of mesh material can be extruded, oriented, expanded, woven, or tubular. Plastic materials that can be used are, for example, polypropylene, polyethylene, PVC coated fiberglass, PVC, or PTFE.

[0126] In some hydrophilic implementations, the mesh material may be made from metal, fiberglass material, polyamide (e.g., nylon), or organic fabrics such as burlap, hemp, or cellulose, or a combination of similar materials. The composition of the hydrophilic mesh material can be further modified by the use of microstructures, coatings, or additives to optimize the contact angle for use in DAC-specific applications.

[0127] In some implementations, the surface properties of the fibers making up the mesh material can be tailored or enhanced to optimize the gas-liquid interface regardless of how hydrophilic or hydrophobic the fiber material begins with. For example, in some cases, deposition of precipitates or solids (such as poorly soluble salts like CaCO3) from one or more fluid flows in a gas-liquid contact application, accumulated over time (and often described as conditioning packing), can change the overall surface energy or topology of the fiber, thereby altering the fiber's interaction with the adsorbent solution (particularly the solution that spans the mesh pores). In some cases, this is based on the effect of the resulting effective contact angle or shape.

[0128] The fibers may also have a surface texture introduced to affect the fiber / sorbent solution interaction properties. The fiber surface may be smooth or roughened, depending on the surface energy properties of the material, to tailor or optimize the properties of the fiber-liquid solution interface.

[0129] In some cases, fibers, whether inherently hydrophobic or hydrophilic in nature, can be optimized through the use of coatings or additives to reach a targeted gas-liquid interface in a given gas-liquid application.

[0130] In some implementations, a combination of fibers exhibiting different surface properties or textures may be woven together as a means of tailoring or optimizing the properties of a sheet of mesh material (sometimes referred to herein as a "mesh sheet") for hold-up and / or run-off of a liquid sorbent solution.

[0131] In both the hydrophobic and hydrophilic mesh material wetting techniques, reduction of mesh material can be achieved by utilizing liquid surface tension properties to achieve a high ratio of gas-liquid interface area to the mass of the packing material. Based on a given liquid solution surface tension, a film of adsorbent solution can span the mesh pore openings, resulting in a total reactive gas-liquid interface area that is greater than the surface area of ​​the mesh packing alone. In these cases, the wetting ratio ε is greater than 100%, so that when the mesh sheet is wetted and the solution spans the open spaces / pores, the gas-liquid interface area is greater than the total surface area of ​​the mesh fibers. Furthermore, the open nature of the pores combined with the solution bridging provides interface area on both sides of the mesh sheet. This is in contrast to some conventional heat exchange packings or structured packing surfaces that may have a gas-liquid interface on one surface, as opposed to the uniform gas-liquid film interface formed on both sides of the mesh packing surface disclosed herein. In some cases, the mesh sheet can be thought of as an internal support for a nearly uniform solution film.

[0132] As mentioned above, commercially available cooling tower packings have difficulty maintaining a high wettable surface area under DAC applications. One cause of poor wetting is the low surface energy of conventional packings. For example, commercially available packings, such as cooling tower packings, tend to be hydrophobic in nature, which tends to have low surface energy. Surface energy represents the strength of intermolecular bonds at the surface of a material, and is the energy required to increase the degree of surface exposure. If a material has a high surface energy, the bulk interactions of the material will be stronger and the surface exposure of the material will be greater. If a material has a low surface energy, the bulk interactions of the material will be weaker and the surface exposure of the material will be less. Poor wetting and hydrophobicity (e.g., tendency to repel water or not mix with water) are usually associated with large contact angles. Contact angle is defined as the angle between the liquid-solid interface and the liquid-vapor interface, measured through the liquid. Both poor wetting and large contact angles are potential causes of packing materials having low surface energy. If not properly designed, these attributes of hydrophobic materials can lead to poor performance in DAC applications.

[0133] The mesh packings of the present disclosure include embodiments that utilize either hydrophobic or hydrophilic properties in a manner that supports better performance in DAC applications, as opposed to the poor wetting of some commercially available cooling tower packings.

[0134] Two broad wetting techniques, the bridge technique and the capillary action technique, are possible when using aqueous liquid capture sorbents. The specific wetting technique can be dictated by the material properties of the mesh sheet fibers making up the mesh sheet. For example, the bridge technique, described in more detail with reference to Figures 14A-14C, occurs when the packing material is more hydrophobic in nature, resulting in the solution establishing liquid films or "bridges" across the mesh pores and between the fibers. The capillary action technique, described in more detail with reference to Figures 15A-15C, occurs when the packing fibers are more hydrophilic in nature. With this technique, capillary action draws the solution along the fiber surfaces, resulting in less or perhaps no bridges across the mesh pores.

[0135] In some implementations involving hydrophobic mesh packing, the hydrophobicity of the mesh fibers encourages the entrapped liquid to migrate preferentially to the open areas of the mesh pores without substantial wetting of the fibers themselves, and any excess liquid can be detached in droplets and run down the mesh fibers.

[0136] Bridging techniques are often found in hydrophobic mesh materials, resulting in solution bridging between fibers due to minimization of the surface energy of the liquid capture sorbent at the liquid interface with the packing fibers in combination with the surface tension of the liquid capture sorbent. In some cases, the dimensions of the bridged solution will be determined by the fiber diameter, spacing (e.g., mesh pore width), hydrophobicity of the fiber material, and surface tension of the solution. A maximized air / sorbent interface for hydrophobic mesh packing applications can be targeted by optimizing the above parameters for a given capture solution composition and the air contactor operating parameters, since a larger air / sorbent interface provides a larger available surface area for increased mass transfer of CO2 to the liquid capture sorbent.

[0137] When using this bridge technique, the surface of the packing fiber itself remains largely unwetted due to its own hydrophobic nature, and therefore does not contribute much to the air / sorbent interface area. Therefore, an optimized hydrophobic mesh packing will maximize the interface area by adjusting the respective fiber diameter and the spacing between the fibers that make up the mesh pores. In some cases, excessively large fiber width / spacing will result in the destruction of the bridge of the adsorbent for a given solution surface tension, in which case the liquid bridge no longer spans the width of the mesh pore.

[0138] In some cases, hydrophilic design can improve the wetting of the mesh packing by the capture solution. With a hydrophilic mesh packing design, the capillary action technique can be the dominant form of wetting of the mesh material. In some cases, this technique may occur through capillary action rather than solution bridging. For example, the capillary action technique draws the solution along the fiber surface with less or perhaps no bridging across the mesh pores. The gas-liquid interface area will then be determined by the area of ​​the wetted fibers and the thickness of the liquid sorbent layer, which in turn will be determined by the hydrophilicity of the fiber material and the flow rate of the liquid sorbent down the mesh sheet. When using this capillary action technique, the mesh pores may or may not be completely wetted depending on the thickness of the liquid sorbent layer and the spacing of the packing fibers. Therefore, the optimization of hydrophilic mesh packing for the capillary action wetting technique will be different from the mesh packing optimization for the bridging technique.

[0139] Improved wetting of mesh packings with hydrophilic properties (e.g., by increasing the wetted surface area of ​​the mesh sheet) can be achieved by at least two approaches. The first approach is to increase the hydrophilicity of the mesh material surface, for example, by increasing the surface free energy, which is a property of the material. The second approach is to increase the surface roughness and apparent contact angle of the mesh material. These approaches to improved wetting can be used independently or in combination with each other.

[0140] Hydrophilic materials for mesh packing may be suitable for gas-liquid contactor applications because the wetted surface area determines the amount of exposure of the capture solution to CO2 in the air, and the surface of a hydrophilic material maximizes the wetted area for a given volume of solution. In some cases, hydrophilicity may be built into the mesh material when fabricated, or may be introduced as a coating after fabrication. The hydrophilic coating increases the surface energy and reduces the contact angle of the capture solution on the mesh sheet. In some cases, some surface treatments that expose the material to changes in the bonding of the material to the surface can achieve similar hydrophilic results.

[0141] In an exemplary implementation, the hydrophilic mesh sheet may include a coating applied to the mesh packing to increase hydrophilicity. In some cases, the coating is fully wetted with minimal solution flow. This can result in higher capture rates with significantly reduced solution flow compared to uncoated mesh sheets.

[0142] In some implementations, the hydrophilic mesh sheet is wetted with the capture solution, soaking the hydrophilic material until the mass or volume of liquid exceeds a threshold saturation level within the mesh sheet and forms droplets that flow along the mesh fibers into the pores (openings) to create a liquid film within the pores in addition to the wetted surface of the hydrophilic mesh material itself. This differs from hydrophobic techniques of wetting, which rely on the mesh material to repel the liquid, forcing the droplets away from the mesh fibers and into the pores.

[0143] In some implementations, the mesh packing can include material additives to further optimize hydrophilicity and reduce the contact angle between liquid-solid interfaces in at least a portion of the mesh sheet.

[0144] In addition or as an alternative to the previous example means for increasing the hydrophilicity of the mesh material, the roughness of the mesh fiber surface may be altered to increase hydrophilicity.

[0145] As seen in FIG. 14A, in some implementations, the mesh packing includes at least a portion of the mesh sheet 901 that has hydrophilic properties. In some cases, this can increase the effectiveness of the mesh sheet 901 in capturing CO2 (sometimes referred to as CO2 capture flux), for example, by at least 10%. This increased effectiveness can be achieved through an increase in the wetting ratio of the mesh packing. If the mesh material is already somewhat hydrophilic in nature (tends to be wetted by water), the addition of a small amount of microstructure can increase the wetted surface area.

[0146] The mesh packing is designed to be positioned in the air flow path of a gas-liquid contactor, such as an air contactor in a DAC application, or a cooling tower housing (if modified or adapted for CO2 capture applications). The mesh packing consists of one or more mesh panels that are sewn and / or aligned to form a relatively straight gas passageway, with the largest surface (planar) area of ​​the mesh sheet being in the same straight line as the flow direction of the gas flow. The top edge of the mesh panel is connected to a liquid distribution system, and a liquid capture solution is applied (e.g., continuously or intermittently using a pulsed flow, a flush flow, or a combination thereof) to the top edge or upper portion of the mesh sheet and allowed to progress down the height of the mesh sheet, forming a uniform liquid film within the majority of the mesh perforations and / or along the fibers that define the mesh perforations. This liquid film provides a gas-liquid interface area through which CO2 from the air flow is absorbed or captured as the air flow travels through the gas passageway between the mesh sheets. The mesh sheet packing disclosed herein has a mesh sheet that is positioned relative to the air flow. For example, in one embodiment, the mesh sheet is positioned in the same linear orientation as the air flow direction, so that the air flow travels along a direction that is parallel to the planar surface of the mesh sheet. In one embodiment, the air flow travels along a direction that is parallel to the air travel depth (ATD) defined by the mesh sheet. The movement of the air flow in this direction allows the air flow to travel along a path or passage that is largely unobstructed for air travel while contacting the capture solution (liquid film) interface area, minimizing pressure loss. In other words, the less restrictive air path created by the mesh sheet orientation reduces the pressure difference along the ATD. When the mesh sheet is positioned parallel to the gas flow direction, it maximizes the gas-sorbent contact efficiency for capturing CO2 from a dilute source such as air.

[0147] High gas velocities, solution properties, and varying operating temperatures can affect the ability of the mesh sheet to maintain a uniform liquid film across the mesh pores (openings), a phenomenon referred to as liquid film stability. In some cases, significant liquid film instability can reduce the overall performance of the mesh packing, resulting in reduced CO2 capture. This problem can arise when the mesh pore size becomes too large to support a liquid film under given operating conditions such as solution properties (surface tension, viscosity, etc.) and gas velocity. The potential increase in the wetted area of ​​the mesh sheet with larger pore diameter, which increases the wetted interface surface area and thereby improves CO2 mass transfer to the liquid, must be balanced with the risk of destabilizing the liquid film, which can reduce the wetted interface area for a given operating condition. To better achieve this balance, the configuration of either hydrophilic or hydrophobic mesh materials for capture of CO2 from dilute sources is optimized to maintain maximized mass transfer with respect to mesh pore size and DAC operating conditions. In some cases, mesh sheets with a range of pore sizes, when selected to handle the operating conditions, can have significantly greater wetted interface areas and lower pressure drops than similar volumes of packing materials commonly used in DAC applications, such as packing or fillers commonly used in the cooling tower industry.

[0148] Mesh packing, when combined with liquid distribution according to the present disclosure, can reduce the sorbent flow rate requirements while still providing uniform liquid distribution throughout the height and length of the sheet. In some cases, the liquid distribution system can include one or more nozzles operable to apply a spray or spray of capture solution to the mesh sheet. The liquid can be applied on or at any point along the mesh sheet (e.g., to wet a dry spot). Given that the mesh sheet surface defines gas passages and is porous, the mesh sheet surface does not form a significant obstacle to air flow (especially compared to packing configurations where the air flow proceeds through the packing block rather than in the same straight line along a planar surface), and the mesh packing and method of operation disclosed herein significantly reduces pressure loss for a given air velocity and ATD, which also reduces the power required to operate the system. It should therefore be understood that in some implementations, the primary direction of airflow through the gas passages will be along the surface of the mesh sheet, with some residual and relatively small volume of air making its way through the mesh sheet given the porous nature of the mesh sheet.

[0149] In some implementations, the mesh packing is operated with a liquid distribution system configured for continuous and / or intermittent flow of capture solution across the mesh packing, where the intermittent flow may be provided in succession or cycles of varying flow rates, such as flush (larger) flow, no flow, and pulse (smaller) flow, each for a discrete period of time. In some cases, this intermittent mode of liquid distribution across the packing is used to reduce or mitigate the formation of trickles. As mentioned above, at low liquid filling speeds, the capture solution may tend to become trickle-like as it travels down the packing. Insufficient or incomplete wetting of the mesh sheet caused by trickles of capture solution may result in less mass transfer due to the reduced interfacial area per unit packing area. In some cases, the use of intermittent, flush, and / or pulse flows can mitigate this problem.

[0150] The mesh packing can provide a significantly larger reactive surface area for a given volume, which can result in a high degree of CO2 capture from the air stream. The mesh sheet surface is exposed to direct sorbent feed (e.g., at the top edge of the mesh sheet or other areas of the mesh sheet), which can result in uniform liquid sorbent distribution across the width of the mesh sheet. In this manner, the mesh material can be completely wetted, avoiding any significant dry or non-wetted areas.

[0151] DAC packing design may aim to maximize and maintain reactive gas-liquid interfacial area and increase solution capture capacity to maximize absolute capture flux (Equation 1) from the reactant gas, e.g., to capture atmospheric CO2 without incurring prohibitive energy or economic penalties. Although solution kinetics dominates, consistent with the double film theory of mass transfer, the availability of CO2 in solution for reaction is governed by the equilibrium solubility of CO2 in the adsorbent medium under the respective conditions, via Henry's constant (Equation 2). Therefore, at optimal process conditions, there will be no depletion of CO2 concentration from the gas phase across the depth of the mesh packing (e.g., infinite air velocity conditions), and the adsorbent will have a uniform capture rate throughout the gas-liquid contactor. However, in reality this is not the case, and the capture flux is driven not only by mass transfer kinetics, but also by depletion throughout the gas-liquid contactor system.

[0152]

number

[0153]

number

[0154] Here,

[0155] [Table 1]

[0156] A model incorporating Equations 1 and 2 above can be used with the mesh packing designs of the present disclosure to provide optimized capture flux. For example, a method of operating a gas-liquid contactor to flow a dilute CO2 gas flow in the same straight line across the plane of the surface of a mesh packing wetted with a capture solution having known solution properties, as described in various embodiments herein, can be shown to support a reduction in pressure drop across the ATD of the packing, allow for increased gas velocity, and also reduce the impact of CO2 capture slope on overall performance.

[0157] Mesh packing with features according to the present disclosure has been designed in embodiments for commercial DAC applications, thereby having the ability to maximize the CO2 gas-liquid interfacial area per unit packing area for efficient capture of CO2 from air while minimizing the mass and energy consumption of the mesh sheet. The mesh packing is designed to include small openings for the solution to bridge and form thin liquid bridges to generate interfacial area for reaction with CO2 to occur. This can improve capture performance and also reduce the volume of material required for a given surface area of ​​mesh packing.

[0158] FIG. 1 shows a schematic diagram of an exemplary gas-liquid contactor 100. The gas-liquid contactor 100 comprises a frame 105, a housing 104, one or more upper distribution reservoirs 107, a plenum 114, a gas moving device (sometimes referred to herein as a fan or blower 102), a fan baffle 103, a bottom liquid collection reservoir 106, at least one section of mesh packing 101, and a control system 999. With reference to FIG. 1, the gas-liquid contactor 100 is a dual cell cross-flow air contactor since the two sections of mesh packing 101 are separated by the plenum 114, and air travels across the mesh packing 101 in a direction that is substantially perpendicular to the flow of liquid from the upper distribution reservoir 107 to the bottom liquid collection reservoir 106. As described in more detail below, other configurations of the gas-liquid contactor 100 are possible. The mesh packing 101 can be molded to conform to the shape of the gas-liquid contactor and sized to fit within the frame 105 and housing 104. In some cases, the gas-liquid contactor can include a cylindrical or conical housing. Although the term "sump" is used throughout this disclosure, any fluid-containing receptacle can be used. Some non-limiting examples include tanks, gutters, and gutters.

[0159] 1, a frame 105 (e.g., a combination of interconnected structural members) provides structural support and stability to the gas-liquid contactor 100, and a housing 104 provides partial enclosure for the illustrated components. With reference to FIGURE 1, the housing 104 defines a portion of a plenum 114, which is a hollow interior of the gas-liquid contactor 100.

[0160] Referring to FIG. 1, the upper distribution reservoirs 107 are formed into or positioned within the frame 105. Each upper reservoir 107 can at least partially contain or store a CO2 capture solution 124 (e.g., liquid sorbent). The CO2 capture solution 124 can flow downward from the upper reservoir 107, for example by gravity flow, uniform flow, or laminar flow, into at least one section of the mesh packing 101, along the planar surface of the mesh packing 101, and finally into one or more bottom collection reservoirs 106. The gas-liquid contactor 100 can include a liquid distribution system 109. The liquid distribution system 109 can include a set of nozzles configured to distribute the CO2 capture solution 124 into the packing 101, a distribution reservoir 107 (also referred to as an upper reservoir), a pressurized header, or a combination thereof. For example, the upper reservoir 107 can hold the CO2 capture solution 124, and a nozzle positioned in the floor of the upper reservoir 107 can flow the CO2 capture solution 124 into at least one section of the mesh packing 101. The CO2 capture solution 124 can flow via gravity through at least one section of the mesh packing 101 and then can be collected in the collection reservoir 106 (also referred to as the bottom reservoir). Other example embodiments of the liquid distribution system 109 are described below.

[0161] As the CO2 capture solution 124 circulates through and across at least one section of the mesh packing 101 in a predominant liquid flow direction, the CO2-containing air 120 flows (e.g., by the action of a fan or blower 102) through at least one section of the mesh packing 101 in a predominant gas flow direction substantially perpendicular to the predominant liquid flow direction, thereby contacting the CO2 capture solution 124. By contacting the two fluids in cross-flow, as depicted in Figure 1, a portion of the CO2 in the CO2-containing air flow 120 is transferred to the CO2 capture solution 124, and the fan 102 positioned in the fan deflector 103 moves the CO2 lean air flow 130 out of the gas-liquid contactor 100 to the atmospheric environment. The CO2-rich solution flows into at least one collection reservoir 106, and one or more pumps recirculate at least a portion of the CO2-rich solution 124 back to at least one upper distribution reservoir 107. The term "air" in the phrase "CO2-containing air" does not limit the mesh packing 101 to being used only to treat atmospheric air. Other gases can also flow through the mesh packing 101. In some implementations, as depicted in FIG. 1, the fan 102 is an induced draft fan that pulls air through at least one section of the mesh packing 101. In some cases, the fan 102 is a forced draft fan that blows or pushes air through at least one section of the mesh packing 101. In some implementations, the gas-liquid contactor 100 can include an induced draft or forced draft blower. In some cases, the CO2 capture solution 124 is provided to at least one section of the mesh packing 101 at a liquid fill rate ranging from 1 L / min to 4 L / min.

[0162] The bottom sump 106 of the gas-liquid contactor 100 acts as a collection tank for the CO2-rich capture solution 124. In some implementations, at least a portion of the solution may be sent downstream to other units or facilities for further processing using either a backflow from a recirculation pump system or a separate pump and piping system. In one embodiment, some or all of the CO2-rich capture solution flows from the gas-liquid contactor 100 to a downstream unit for additional processing. For example, the CO2 capture solution 124 can be regenerated and some or all of the absorbed CO2 can be recovered from the CO2-rich solution. The regenerated CO2 capture solution 124 can be sent back to the gas-liquid contactor 100.

[0163] In some implementations, rather than the dual cell cross-flow configuration depicted in Figure 1, the gas-liquid contactor system 100 can consist of one or more gas-liquid contacting cells, each with one or more fans similar to larger industrial cooling tower systems. Some non-limiting examples of other possible configurations for the gas-liquid contactor system 100 are described with reference to Figures 1A and 1B.

[0164] Referring to FIG. 2, the gas-liquid contactor system 200 is an upright body. The gas-liquid contactor system 200 has an air inlet 110 along the bottom through which the CO2-containing air 120 is admitted into the gas-liquid contactor system 200. The fan 102 rotates about a fan axis to draw the CO2-containing air 120 upward through the air inlet 110 to contact an area of ​​the mesh packing 101. In the configuration of FIG. 2, the gas-liquid contactor system 200 has only one area of ​​the mesh packing 101, and therefore may be referred to as a "single cell" gas-liquid contactor system 200. The CO2 capture solution 124 circulates downward in the mesh packing 101, for example by gravity flow, uniform flow, or laminar flow, and eventually flows into one or more bottom collection reservoirs 106. As the CO2 capture solution 124 circulates through and across the mesh packing 101, the CO2-containing air 120 flows upward through the mesh packing 101 (e.g., by the action of the fan 102), thereby contacting the CO2 capture solution 124. Thus, the flow of the CO2 capture solution 124 through the mesh packing 101 in FIG. 2 is countercurrent or opposite to the flow of the CO2-containing air 120 through the mesh packing 101. A portion of the CO2 in the CO2-containing air flow 120 is transferred to (e.g., absorbed by) the CO2 capture solution 124, and the fan 102 moves the CO2-lean air flow 130 out of the gas-liquid contactor 200 to the atmospheric environment. The CO2-rich solution flows to at least one collection reservoir 106.

[0165] Referring to FIG. 3, the gas-liquid contactor system 300 is an upright body. The gas-liquid contactor system 300 has an air inlet 110 along an upright side portion through which the CO2-containing air 120 is admitted into the gas-liquid contactor system 300. The fan 102 rotates about a fan axis to draw the CO2-containing air 120 substantially horizontally through the air inlet 110 and into contact with an area of ​​the mesh packing 101. In the configuration of FIG. 3, the gas-liquid contactor system 300 has only one area of ​​the mesh packing 101, and therefore may be referred to as a "single cell" gas-liquid contactor system 300. The CO2 capture solution 124 circulates downwards through the mesh packing 101, for example by gravity flow, uniform flow, or laminar flow, and eventually flows into one or more bottom collection reservoirs 106. As the CO2 capture solution 124 circulates through the mesh packing 101, the CO2-containing air 120 flows substantially horizontally through the mesh packing 101 (e.g., by the action of the fan 102), thereby contacting the CO2 capture solution 124. Thus, the flow of the CO2 capture solution 124 through the mesh packing 101 in FIG. 3 is substantially perpendicular to the flow of the CO2-containing air 120 through the mesh packing 101. Such a configuration of flows can be referred to as a "cross-flow" configuration. A portion of the CO2 in the CO2-containing air flow 120 is transferred to the CO2 capture solution 124, and the fan 102 moves the CO2-lean air flow 130 out of the gas-liquid contactor 300 to the atmospheric environment. The CO2-rich solution flows to at least one collection reservoir 106. Although in the embodiment, one or more regions of mesh packing 101 are shown having a substantially upright orientation (i.e., defining a plane having an upright orientation), one or more regions of mesh packing 101 may have a substantially horizontal orientation (i.e., may define a plane having a horizontal orientation). Similarly, one or more regions of mesh packing 101 may have an orientation that forms a non-zero angle with a vertical and / or horizontal plane.

[0166] Referring to FIG. 1, the exemplary gas-liquid contactor system 100, as well as other exemplary implementations according to the present disclosure, includes a process flow (also referred to as a "flow") in the gas-liquid contactor used to capture CO2. The process flow, as well as downstream process flow to which the gas-liquid contactor system is fluidly coupled, can be flowed using one or more flow control systems (e.g., control system 999) implemented throughout the system. The control system 999 can include one or more flow pumps, fans, blowers, or solids conveyors for moving the process flow, one or more feed pipes or conduits through which the process flow is flowed, and one or more valves for regulating the flow of the flow through the pipes. Each of the configurations described herein can include at least one variable frequency drive (VFD) coupled to a respective pump that can control at least one inlet liquid flow rate or at least one outlet liquid flow rate. In some implementations, the liquid flow rate is controlled by at least one flow control valve.

[0167] In some embodiments, the flow control systems 999 can be operated manually. For example, an operator can set the flow rate for each pump or transfer device and can set the open or closed position of the valves to regulate the flow of the process fluid through the pipes in the flow control systems 999. Once an operator sets the flow rate and the open or closed position of the valves for all flow control systems 999 distributed throughout the system, the flow control systems can flow fluids under certain flow conditions, e.g., a constant volumetric flow rate or other flow conditions. To change the flow conditions, an operator can manually operate the flow control systems 999, e.g., by changing the pump flow rate or the open or closed position of the valves.

[0168] In some embodiments, the flow control systems 999 may be operated automatically. For example, the flow control systems 999 may be communicatively coupled to a computer or computer readable medium storing instructions (such as flow control instructions and other instructions) executable by one or more processing devices to perform operations (such as flow control operations). An operator may use the control system 999 to set the flow rates and open or closed positions of valves for all flow control systems 999 distributed throughout the facility. In such embodiments, an operator may manually change the flow conditions by providing input through the control system 999. Also, in such embodiments, the control system 999 may automatically (i.e., without manual intervention) control one or more of the flow control systems, such as, for example, using a feedback system connected to the control system 999. For example, sensors (such as pressure sensors, level sensors, flow sensors, temperature sensors, or other sensors) may be connected to pipes through which the process streams flow. The sensors may monitor and provide flow conditions (such as pressure, temperature, or other flow conditions) of the process streams to the control system 999. In response to a flow condition exceeding a threshold (such as a threshold pressure value, a threshold temperature value, or other threshold), the control system 999 can automatically implement one or more actions. For example, if the pressure or temperature in the line exceeds a threshold pressure value or temperature value, respectively, the control system 999 can provide a signal to a pump to reduce flow rate, a signal to open a valve to relieve pressure, a signal to interrupt the flow of a process stream, or other signal. For example, if a flow sensor monitoring gas velocity at an inlet or mesh packing reads that the gas velocity is above a threshold gas velocity value, the flow sensor can send a signal to a controller in the control system 999 instructing a fan to reduce the fan speed.

[0169] In another example, the control system 999 can be communicatively coupled to a variable frequency drive (VFD) pump and a liquid dispensing system responsive to a controller in the control system 999. If a flow sensor reads that the liquid fill rate (flow rate of capture solution into the mesh packing) is above a threshold flow rate value, the flow sensor can send a signal to a controller in the control system 999 to slow down the rotational speed of the motor in the VFD pump, thereby slowing down the liquid fill into the mesh packing. In another example, the control system 999 can be communicatively coupled to a control valve and a nozzle that dispenses liquid into the mesh packing. If a flow sensor reads that the liquid fill rate is above a threshold flow set point value, a signal is sent to the control valve to partially close to reduce the flow rate.

[0170] 4, the gas-liquid contactor 400 comprises a structural support system 401 for at least one section of the mesh packing 101. The structural support system 401 comprises one or more support bars, support beams 204, a top spacer, a bottom spacer, at least one air inlet area for the CO2-containing air flow 220, and at least one outlet area for the CO2-lean air flow 230. The one or more support bars comprise a first subset of bars (also referred to as top bars 206) and a second subset of bars (also referred to as bottom bars 208). The terms "top" in the top bars and "bottom" in the bottom bars do not limit the bars to a particular location relative to other elements of the gas-liquid contactor 400. Other elements may be positioned above the top bars 206 and / or below the bottom bars 208. The mesh packing 101 comprises a number of mesh panels 202a, 202b (two are shown in FIG. 4, but more are possible). Each mesh panel 202a, 202b is a section of the mesh packing 101 that comprises or consists of a mesh material 203. The mesh material 203 can take any suitable form. For example, in one implementation, the mesh material 203 is a porous sheet (e.g., a screen), sometimes referred to herein as a "mesh sheet." In another possible example, the mesh material 203 is a rigid body with small holes extending throughout it. The mesh material 203 is a porous body with a length and width that are orders of magnitude greater than its thickness or depth. The mesh material 203 of each mesh panel 202a, 202b is held by one or more of the top bars 206 and one or more of the bottom bars 208 so that there is sufficient tension acting on the mesh material 203. For example, the mesh material 203 may have sufficient tension to form a planar surface. The tension of the mesh material 203 may be adjusted to adjust the flow characteristics of the CO2 capture solution 124 or the sorbent flow.Referring to FIG. 4, the top bar 206 is attached to one or more support beams 204 and positioned to allow flow of the CO2 capture solution 124 or sorbent from a distribution reservoir (such as distribution reservoir 107) to the upper portions of the mesh panels 202a, 202b. The support beams 204 may have an orientation that is transverse or perpendicular to the orientation of the top bar 206. In the configuration of FIG. 4, the CO2 capture solution 124 is introduced to the top of the mesh panels 202a, 202b. In alternative configurations, the CO2 capture solution 124 is introduced at different locations on the mesh panels 202a, 202b. In some cases, the CO2 capture solution 124 flows to the mesh panels 202a, 202b at a solution fill rate ranging from 1 L / min to 4 L / min.

[0171] 4, the mesh panels 202a, 202b and the top bar 206 are not self-supporting. Therefore, additional structural support is provided, such as a support beam 204 and one or more support columns 214. These components may be connected to one or more of the mesh panels 202a, 202b and the housing 104 (see FIG. 1). The support beam 204 may be supported at an intermediate location within the frame 105 of the gas-liquid contactor, either through a rigid connection as shown in FIG. 4 or by use of a cable, rope, or wire. In an embodiment, the support beam 204 may be connected to an upper spacer to maintain a constant distance between the top bar 206 and the mesh material 203. In an embodiment, the position of the mesh material 203 relative to the bottom bar 208 is adjustable such that the mesh material 203 is connected to, contacts, or is spaced apart from the bottom bar 208, such as to maintain a constant distance between the bottom bar 208 and the top bar 206. In one embodiment, the gaps between the mesh material 203 of adjacent mesh panels 202a, 202b create gas passageways.

[0172] 4, the CO2-containing gas flow 220 enters and flows across the mesh panels 202a, 202b in the same linear direction. By "same linear" it is understood that the CO2-containing gas flow 220 flows along a direction that is parallel to the planar surface of the mesh material 203. For example, with reference to FIG. 4, the CO2-containing gas flow 220 flows along a substantially horizontal direction, with the planar surface of the mesh material 203 being parallel to the plane of the page of the drawing showing FIG. 4. A flow of liquid sorbent (such as the CO2 capture solution 124) flows from the top of the mesh material 203, creating a liquid film across at least a portion of the pores of the mesh material 203. The CO2-containing gas flow 220 and the CO2 capture solution 124 contact in a cross-flow manner such that at least a portion of the CO2 in the CO2-containing gas flow 220 is absorbed into the CO2 capture solution 124 before the air flow leaves the mesh panels 202a, 202b and is discharged from the gas-liquid contactor as a CO2-thin air flow 230 through at least one exit area.

[0173] 5, an example of a structural support system 500 includes a plurality of upper bars 206 supported by and extending between support beams 204. Each support beam 204 is supported by and extends between support columns 214. The illustrated section of the mesh packing 101 includes a plurality of mesh panels 202. Each mesh panel 202 is supported by one of the upper bars 206 and extends between adjacent support beams 204. The mesh panels 202 have an upright orientation. The mesh panels 202 can extend in a direction that is perpendicular to the ground. The CO2-containing gas flow 220 flows along a direction that is parallel to the planar surface of the mesh material 203 of each mesh panel 202. For example, referring to FIG. 5, the CO2-containing gas flow 220 flows along a direction that is perpendicular to a normal vector to the normal vector of the plane of the mesh panel 202. Referring to FIG. 5, the CO2-containing gas flow 220 flows along a second dimension defined along a direction parallel to the air travel depth ATD defined by each of the mesh panels 202, the ATD being the distance of the mesh material 203 crossed by the air flow for the purpose of capturing CO2 from the CO2-containing gas flow 220. Referring to FIG. 5, the mesh panels 202 of the mesh packing 101 are spaced apart from each other. In the configuration of the mesh packing 101 of FIG. 5, the mesh panels 202 are spaced apart from each other in a horizontal direction or in a direction transverse or perpendicular to the ATD. The spaced apart mesh panels 202 define a gas passageway. For example, two adjacent mesh panels 202 are spaced apart along a first dimension. In the configuration of FIG. 5, the first dimension is a gas passageway spacing 207 corresponding to the width of the gas passageway 408 between the two adjacent mesh panels 202. The gas passageway 408 is described in more detail below.

[0174] Other configurations of the mesh packing 101 are possible. For example, referring to FIG. 6, the mesh packing 101 has a substantially horizontal orientation at the point where the planar surface formed by each mesh panel 202 is defined by a normal vector having an upright orientation. The mesh panels 202 are stacked on top of each other to form the mesh packing 101. The CO2-containing gas flow 220 flows along a direction that is parallel to the planar surface of the mesh material 203 of each mesh panel 202. The CO2-containing gas flow 220 flows along a direction that is parallel to the ATD defined by each of the mesh panels 202. A flow of liquid sorbent, such as the CO2 capture solution 124, flows from above the mesh material 203, creating a liquid film across the pores of at least a portion of the mesh material 203 of one or more mesh panels 202. In a "co-current flow" configuration, an example of which is shown in FIG. 6, the CO2 capture solution 124 is conveyed to the mesh packing 101 along a direction that is parallel to the direction along which the CO2-containing gas flow 220 flows. In such a configuration, the CO2 capture solution 124 may be provided as a fine particle liquid-air mixture (e.g., sprayed, sparged, or provided by a cascade from one or more nozzles). In such a configuration, the CO2 capture solution 124 may be provided as a spray through a nozzle such that droplets of the CO2 capture solution 124 are entrained in the CO2-containing gas flow 220. Formation of the CO2 capture solution 124 may be provided to the mesh panel 202 further along the ATD if needed or desired. Regardless of the flow direction, the CO2 capture solution 124 wets the mesh material 203 of the one or more mesh panels 202. The CO2-containing gas flow 220 contacts the CO2 capture solution 124 in the mesh material 203 such that at least a portion of the CO2 in the CO2-containing gas flow 220 is absorbed into the CO2 capture solution 124 before the air flow leaves the mesh panel 202 and is discharged from the outlet of the gas-liquid contactor as a CO2-thin air flow 230.

[0175] In some implementations, the mesh packing 101 (consisting of one or more mesh panels 202a, 202b) can be installed as separate cells in the gas-liquid contactor 100 to further increase the gas-liquid surface area within the existing frame dimensions and housing of the gas-liquid contactor 100.

[0176] In some implementations, the mesh panels 202a, 202b can be replaced with new or repaired mesh panels 202a, 202b if some portion of the original mesh material 203 is damaged. In some cases, the mesh panels 202a, 202b can be detached from the bars 206, 208 when the bars 206, 208 are decoupled from the support beams 204.

[0177] The same linear orientation of the mesh panels 202a, 202b with the direction of airflow allows a generally unobstructed path (or passage) for the air to travel, minimizing pressure loss. Stated another way, the less restrictive air path created by the orientation of the mesh panels 202a, 202b parallel to the airflow reduces the pressure differential along the ATD.

[0178] In some implementations, the mesh panels 202a, 202b are themselves structural components that can serve as internal support for the nearly vertical solution film. In some cases, the type of weave pattern for the mesh material 203 that defines the pore shape can be configured to balance solution hold-up and film flow along the mesh material 203. Also, wider mesh weaves can have less material density, minimizing the mass of the mesh material 203 for a given mesh area. In some implementations, there is a threshold mesh weave width where solution can no longer span across the fibers to create a continuous film.

[0179] Fasteners may be used to secure the sheet of mesh material 203 so that it is uniformly stretched and has a (rigid) tensioned surface. Some examples of types of fasteners that may be used include adhesives, clamps, clips, screen fasteners, brackets, etc. In some cases, the tension of the mesh material 203 may be set with fasteners at several anchoring positions. In some cases, the weight of the bars, spacers, or a combination thereof provides sufficient tension for the mesh material 203. Sufficient tension may be achieved when the movement of the mesh panels 202a, 202b is restricted so that adjacent mesh panels 202a, 202b do not contact each other and do not impede airflow. In some cases, the support bars may be connected to a tensioning frame that allows for adjustment of the tension. For example, the tensioning frame may include a set of unistruts with spreader bolts that can be adjusted to move the bars to achieve the desired tension in the mesh material 203 that are sewn or secured to the bars.

[0180] In some cases, the mesh packing 101 is modular or compact and can be easily installed in an existing gas-liquid contactor (or potentially a cooling tower) without requiring modifications. The mesh packing 101 can be installed above at least one bottom collection sump.

[0181] The mesh material 203 is selected to be compatible with the CO2 capture solution 124. For example, the mesh material 203 can be compatible with a capture solution having a high pH, ​​a hydroxide solution (e.g., KOH, NaOH), a bicarbonate / carbonate solution, an amine solution, or a combination thereof.

[0182] In some implementations, some or all of the mesh packing 101 and / or structural support components are made from materials that do not significantly corrode, deteriorate, or deteriorate in the presence of process fluids, thereby avoiding premature replacement of the gas-liquid contactor. For example, the beams 204 and posts 214 can be made from wood, metal, or plastic materials, while the bars 206, 208 can be made from plastic or metal materials (e.g., PVC, acrylonitrile butadiene styrene (ABS), or other thermoplastics), and the mesh material 203 can include metal, PVC, polymer, plastic, or organic materials. In applications using strong alkaline chemicals such as hydroxide solutions, the wetted materials (e.g., mesh material 203, bars 206, 208, beams 204, and posts 214) can be selected to withstand deterioration caused by exposure to these solutions. In some cases, these materials can include stainless steel, plastic, PVC, HDPE, PTFE, and the like.

[0183] In some implementations, the top 206 and bottom 208 support bars can be thin poles, straps, ropes, cables, etc. to create minimal gas passageways while still accepting direct adsorbent flow and allowing for an evenly distributed liquid film across the mesh material 203 and an increased reactive interface or surface between the gas flow and the adsorbent.

[0184] FIG. 7 illustrates an example bar design that may be implemented in the structural support systems 800, 900 of FIGS. 8A and 9, respectively. In some implementations, the top bar may include a number of grooves 703 cut into it to form a grooved bar 702, which may direct the capture solution 124 into the mesh material 203. The mesh material 203 may be held between the grooved bars 702 such that the surfaces with the grooves 703 face each other. The grooves 703 may direct the capture solution 124 down into the mesh material 203. In some implementations, the top bars may be shaped or configured to interlock with each other. For example, the cross section of the top bar 704 may be C-shaped or arcuate, and the top bar 206 may interlock with each other. In some implementations, the cross sections of the top bars, such as top bar 708, may be U-shaped and may interlock with each other. In some implementations, the top bar can taper in thickness from one end to the other, such as tapered bar 706. This allows the mesh packing 101 to be more easily installed in certain gas-liquid contactors (e.g., gas-liquid contactor frames that are rounded or cylindrical). Any of the bar designs 700 can be implemented as a bar or spacer in the structural support systems 800, 900 shown in Figures 8A and 9, respectively.

[0185] FIG. 8A illustrates an exemplary mesh packing 801 and structural support system 800. This system is similar to the previous embodiment in that the structural support system 800 includes one or more top bars 206, one or more bottom bars 208, one or more support columns 214, and one or more support beams 204. The structural support system 800 of FIG. 8A includes one or more upper spacers 210 and one or more lower spacers 212. In some cases, the top support bars 206 and the bottom support bars 208 are maintained at a fixed distance by using one or more upper spacers 210 and lower spacers 212, respectively. The spacers 210, 212 can provide lateral and torsional stiffness to the bars 206, 208. In some cases, the tension of the mesh material 203 can be set at the anchoring position 215. In some cases, the weight of the bottom bars 208, the lower spacers 212, or a combination thereof provides sufficient tension for the mesh material 203. In some cases, the top support bar 206 and the bottom support bar 208 may be connected to a tensioning frame that allows for adjustment of tension. For example, the tensioning frame may include a set of unistruts with an expansion bolt that can be adjusted to move the top support bar 206, the bottom support bar 208, or both, to achieve a desired tension in the mesh material 203 that is sewn or secured to the bars. The spacers 201, 212 help adjust the position of the mesh material 203, such as to maintain a constant distance between the bars 206, 208 and the mesh material 203. In some embodiments, the position of the mesh material 203 relative to the bars 206, 208 is adjustable such that the mesh material 203 can be coupled to, contacted with, or spaced apart from the bars 206, 208, such as to maintain uniformity between adjacent mesh panels 202. In the configuration of the mesh packing 801 of FIG. 8A, the mesh packing 801 includes a single mesh panel 802. A single continuous sheet of mesh material 203 is sewn through top support bars 206 and bottom support bars 208 to form individual mesh panel sections 209 of a single mesh panel 802 .Each mesh panel section 209 is a portion of a continuous sheet of mesh material 203 defined between top bar 206 and bottom bar 208. The continuous sheet of mesh material 203 may be sewn around top support bar 206 and bottom support bar 208 to form the entire volume of mesh packing 801.

[0186] The structural support system 800 also aids in the formation of various gas passages 408 between the mesh panel sections 209. Each gas passage 408 is a volume defined between adjacent spaced apart mesh panel sections 209 or between the mesh panel sections 209 and an interior wall of the housing 104 of the gas-liquid contactor 100. Referring to FIG. 8A, each pair of adjacent mesh panel sections 209 are spaced apart from each other in a first direction D1 to define a gas passage spacing 207 for each gas passage 408. The first direction D1 is transverse to the depth ATD through which the air travels (see FIG. 5). The first direction D1 is defined in a plane that is perpendicular to the depth ATD through which the air travels. In the embodiment of FIG. 8A in which the mesh panel sections 209 have an upright orientation (e.g., a vector perpendicular to the mesh panel sections 209 has a horizontal orientation), the gas passage spacing 207 is the width of the gas passage 408. In an alternative embodiment in which the mesh panel sections 209 have a horizontal orientation (e.g., a vector perpendicular to the mesh panel sections 209 has an upright orientation), the gas passage spacing 207 (first dimension) is the height of the gas passages 408. The gas passage spacing 207 may be used to define other dimensions of the gas passages 408. Each mesh panel 202 defines at least two gas passages 408, one on each side of the mesh panel section 209.

[0187] With reference to FIG. 5, the air travel depth (ATD) is defined along a transverse direction to the gas passage spacing 207. With reference to FIG. 5, the air travel depth is defined in a plane that is perpendicular to the gas passage spacing 207. With reference to FIG. 5, the air travel depth is defined in a plane that is perpendicular to the plane in which the gas passage spacing 207 is defined. In one possible configuration of the mesh packing 101 of FIG. 5, the mesh panel 202 has an upright orientation, and the air travel depth (ATD) is less than three orders of magnitude greater than the gas passage width 207. For example, a mesh panel having a width of 6 ft and a height of 8 ft may have a gas passage width of approximately 0.25 inches. Other dimensions of the mesh panel and gas passage width are possible. In one possible configuration, the air travel depth ATD is between one and two orders of magnitude greater than the gas passage width 207. In some implementations, the gas passage width may be 0.25 inches or greater. The use of the term "air" in the depth ATD through which the air travels does not limit the gas passage 408 to being used only to direct air. Other gases may flow through the gas passage 408.

[0188] In the configuration of mesh packing 101 of FIG. 6 in which the mesh panels 202 have an upright orientation, each gas passage 408 has a length / depth defined in a direction parallel to the depth through which the air travels, a width defined in a direction perpendicular to the depth through which the air travels (i.e., gas passage spacing 207), and a height defined in a direction parallel to the vertical.

[0189] The structural support system 800 of FIG. 8A allows the mesh panels 202 to have different shapes and angles by adjusting the offset between the top bar 206 and the bottom bar 208, by adjusting the spacing between adjacent bars 206, 208, by adjusting the diameter / width of the bars, and / or by adjusting the stitching pattern, any of which may further affect the shape, size, and / or orientation of the gas passages 408. For example, the top bar 206 may be laterally offset from the bottom bar 208 such that laterally adjacent mesh panels 802 are parallel to one another. Alternatively, one or more of the mesh panels 802 may be offset at a non-zero angle from the vertical, which further changes the shape of the gas passages 408 or the orientation of the gas passages 408 from the vertical, respectively.

[0190] The cross-sectional shape of each gas passage 408 is defined in a plane perpendicular to the ATD. In an embodiment, an example of which is shown in FIG. 8A, the cross-sectional shape of each gas passage 408 is constant. In an embodiment, an example of which is shown in FIG. 8A, the cross-sectional area of ​​the cross-sectional shape is the same for each gas passage 408. In alternative configurations, the cross-sectional shape of the gas passage 408 for a given section of the mesh packing 801 varies. Different cross-sectional shapes for the gas passage 408 are possible and are within the scope of the present disclosure. For example, referring to FIG. 8A, the configuration of the bars 206, 208 causes each gas passage 408 to have a cross-sectional shape that tapers toward either the top bar 206 or the bottom bar 208. The cross-sectional shape of the gas passage 408 can enable a reduced liquid flow rate of the CO2 capture solution 124 and the creation of a thin liquid film across at least one side of the one or more mesh panels 802. In some cases, the configuration of the mesh panel 802 can allow for even distribution of the adsorbent on both surfaces of the mesh material 203. Any suitable width for the gas passages 408 may be used. Some non-limiting examples of widths for the gas passages 408 include between 0.01 inches and 6 inches. In some implementations, the maximum distance or width of the gas passages 408 is less than 6 inches. In an embodiment, an example of which is shown in FIG. 8A, the gas passage spacing 207 (e.g., the gas passage width in FIG. 8A) decreases in a direction parallel to the distance between the bars 206, 208.

[0191] Various potential configurations of the gas passage 408 are possible, which may be defined by the cross-sectional shape defined by the mesh panel 802. The cross-sectional shape of the gas passage 408 may be determined by the positioning and spacing of the top and bottom support bars 206 and 208, and the upper and lower spacers 210 and 212, respectively. Non-limiting examples of cross-sectional shapes for the gas passage 408 include triangular, rectangular, or angled. Some examples are shown in FIGS. 8A-8J. For example, possible implementations may include gas passages 408 having triangular cross-sectional shapes (as depicted in FIGS. 8A, 8E, 8F, and 8H), parallel rectangular cross-sectional shapes (as depicted in FIGS. 8B, 8I, and 8J), offset triangular cross-sectional shapes (as depicted in FIG. 8E), and parallel angled triangular cross-sectional shapes (as depicted in FIG. 8C). Horizontal configurations of cross-sectional shapes for the gas passage 408 are also possible, along with the inclusion of lateral support bars. Examples of horizontal cross-sectional shapes for the gas passages 408 are shown in Figure 8G (horizontal triangle) and Figure 8D (horizontal rectangle). In some implementations, the gas passages 408 can have cross-sectional shapes that are non-parallel and angled, which can form asymmetric cross-sectional shapes. It is understood that this list is not exhaustive and there can be combinations and permutations of these configurations that can be used.

[0192] 9, the illustrated structural support system 900 is similar to the previous embodiment in that it includes one or more top bars 206, one or more bottom bars 208, one or more support columns 214, one or more support beams 204, one or more upper spacers 210, one or more lower spacers 212, and one or more sheets of mesh material 203. The structural support system 900 is configured to allow stitching of a single sheet of mesh material 203 around the top support bars 206 and bottom support bars 208 to form the entire volume of the mesh packing 101. The structural support system 900 is also designed to allow for the formation of various gas passageway 408 shapes and angles by adjusting the offset between the top and bottom bars, the spacing between adjacent bars, the diameter / width of the bars, and / or the stitching pattern. Each gas passage 408 has a length defined in a direction parallel to the ATD, a width defined in a direction perpendicular to the ATD, and a height defined in a direction parallel to the vertical. The cross-sectional shape of each gas passage 408 is defined in a plane perpendicular to the ATD.

[0193] In some cases, the exemplary mesh packing and support structural components may be positioned in the gas-liquid contactor below the liquid distribution system, one or more upper liquid sumps, or a combination thereof.

[0194] In some implementations, the mesh panel 202 is formed from a single sheet of mesh material 203 that may be sewn, sometimes in an alternating pattern, between offset top and bottom bars 206, 208 to tension the mesh panel 202 and to further provide an expanded interface area. In some cases, securing the sheet of mesh material 203 such that the mesh material 203 has a uniformly stretched (rigid) tensioned surface may be accomplished through the use of fasteners. For example, types of fasteners that may be used to secure the mesh material 203 are adhesives, clamps, clips, screen fasteners, brackets, or combinations thereof.

[0195] In some cases, the single sewn mesh material 203 can be easily replaced with a new mesh sheet if a portion of the mesh material 203 becomes damaged. The mesh material 203 can be removed from the bar when it is disconnected from the support beams 204. In another possible configuration, each mesh panel 202 has its own mesh material 203, and each mesh panel 202 is individually attached to the structural support system 401, 500, 800, 900.

[0196] In some implementations, the mesh packing 101 is designed to be compatible with factory or manufacturer site fabrication and to reduce the amount of on-site fabrication required. The mesh packing 101 can be easily installed in the contactor housing 104 without requiring significant redesign. The mesh packing 101 reduced the amount of on-site labor. The mesh packing 101 can also be installed in a contactor housing 104 designed to operate without the existing structural elements of the cooling tower. In some cases, the mesh packing 101 comprises a low-cost, lightweight sewn-in mesh material 203 with long-term structural integrity.

[0197] 10 depicts a front elevational view of an exemplary mesh packing 101 and structural support system 1000, as viewed from the end of the mesh packing 101 where the CO2-containing air flow 120, 220 enters the mesh packing 101. A single sheet of mesh material 203 is sewn across the top support bars 206 and bottom support bars 208. In this implementation, one or more top support bars 206 are connected to the support beams 204, and both the top bar 206 and bottom bar 208 are configured to allow ease of guiding and sewing the mesh material 203 through the support structure. The gas passageway 408 has a substantially constant cross-sectional area and a substantially constant cross-sectional shape.

[0198] In some implementations, the upper distribution reservoir may include one or more openings for introducing liquid capture solution to the top of the mesh packing 101. The solution may be distributed into a partially enclosed space consisting of the top edges of one or more sheets of mesh material 203, the support beams 204, the top bars 206, and the upper spacers 210. In some cases, the structural support system 1000 may be configured to distribute the liquid capture solution evenly across the mesh packing 101 and to maintain optimal spacing between the gas passages 408. The even distribution of the liquid capture solution across the mesh material 203 creates a thin film of solution that moves with the flow of gravity.

[0199] In some cases, the sheets of mesh material 203 are staggered and sewn between offset upper support bars 206 and lower support bars 208 as depicted in Figure 10. The same linear and parallel orientation of the mesh panels is in the direction of airflow, and the structure of the mesh packing 101 is maintained by providing vertical tension to the sheets of mesh material 203.

[0200] In some implementations, the sheet of mesh material 203 requires direct tension to provide the necessary surface area for gas-liquid contact. In some cases, one edge of the mesh material 203 can be secured to the first top bar 206 and a second edge of the mesh material 203 can be secured to the further final top bar 206, or one edge of the mesh material 203 can be secured to the first bottom bar 208 and a second edge of the mesh material 203 can be secured to the further final bottom bar 208, or other similar combinations.

[0201] The ease of installation and removal of the mesh sheet 203 can be beneficial for large-scale DAC deployments. The mesh packing 101 and structural support system 1000 allow for the delivery of large rolls of continuous sheets of mesh material 203 to the site. These rolls of mesh material can be sewn over and under each of the top and bottom bars 206 and 208, anchored, and pulled in place, allowing for easy installation (and replacement as needed if soiled or damaged). In some implementations, the rolls of mesh material 203 can be cut to size (e.g., approximately the height and width of the gas-liquid contactor inlet) to form a set of mesh panels, and each individual mesh panel can be secured to the top and bottom bars 206 and 208 by bolts, fasteners, adhesives, or other fasteners to form a section. Maintenance of the mesh packing 101 can be advantageous over conventional gas-liquid contactor designs. If a particular mesh panel, bar, or spacer is damaged (e.g., torn, bent, dislodged), the section containing the damaged element can be isolated from other sections of the mesh packing and removed for repair without requiring significant handling of other components of the gas-liquid contactor. For example, if a particular mesh panel is damaged, the damaged mesh panel can be accessed through the gas inlet or plenum of the gas-liquid contactor and removed without requiring opening the housing. If the mesh panel is bonded to the bar or spacer, the damaged mesh panel can be removed, repaired, and reattached to the bar or spacer (e.g., by gluing or re-tensioning / re-stitching the mesh material). In contrast, with conventional packing, if a portion of the packing is damaged, an entire block or section of conventional packing must be discarded. By comparison, for conventional gas-liquid contactor designs, maintenance or removing the mesh packing 101 typically requires a shutdown of the entire unit.

[0202] In one embodiment, the mesh packing 101 is a unit that is prefabricated or assembled off-site or away from the gas-liquid contactor 100 and installed as a single unit into the gas-liquid contactor 100 for installation, repair, or replacement purposes. In one possible example of such a prefabricated mesh packing 101, the mesh packing 101 includes mesh panels 202 and one or more sheets of mesh material 203 that are installed in a supporting structure to create gas passages 408. As such, a supporting structure may be coupled to a structure within the gas-liquid contactor 100 in order to install the prefabricated mesh packing 101 into the gas-liquid contactor 100.

[0203] In some implementations, it may be advantageous to integrate the support system with the upper reservoir (e.g., to save material costs by eliminating the need for a separate upper reservoir). The integrated support system may reduce the number of steps to install the gas-liquid contactor on-site because a separate self-supporting upper reservoir is eliminated and therefore does not need to be installed. The top bars 206 and the upper spacers 210 may form at least a portion of the floor of the upper reservoir. For example, the top bars 206 and the upper spacers 210 with an intervening sheet of mesh material 203 may be pressed together to form the floor of the upper reservoir. In some cases, the top bars 206, the upper spacers 210, the bottom bars 208, the lower spacers 212, or combinations thereof may be integrally formed with the sheet of mesh material 203. For example, the mesh material 203 may be coupled to the bars and spacers that form at least a portion of the upper reservoir, and the entire structure may be dipped or coated with resin. After the resin cures, openings can be formed (e.g., punched or drilled) for the sorbent to flow from the top bar and upper spacer into the mesh material 203. This approach can result in an integrally formed structure that integrates the mesh packing 101, support system 1000, and upper reservoir.

[0204] In some implementations, the mesh packing 101 and support system 1000 may include fiberglass reinforced materials to increase stiffness while reducing overall weight. For example, the top bars 206, the upper spacers 210, the bottom bars 208, the lower spacers 212, or a combination thereof may include a fiberglass core that is at least partially covered with a PVC covering. In some cases, covering the fiberglass with PVC may be done during the manufacture of the mesh material. For example, a fiberglass sheet having small holes may be dipped or covered with PVC, and then compressed air may be used to blow out the portion of the PVC that covers the holes, thereby forming the PVC-coated fiberglass mesh material 203. For example, the bars and spacers, which may include fiberglass material, may be attached to the mesh material, and then the bars and spacers may be covered with PVC by vacuum forming or thermoforming. The PVC covering may bond each of the bars, spacers, and mesh material to form an integrally formed structure.

[0205] In some cases, the fiberglass reinforcement material can be at least partially covered with a resin coating to create an integrally formed mesh packing and support system. In some implementations, a PVC-coated or resin-coated fiberglass mesh material can be molded to include an imprinted texture, such as that depicted in Figures 18A and 18B.

[0206] In some implementations, the top bar 206 can be directly interfaced with or incorporated into a liquid solution distribution system that may include a series of troughs or other channels that allow the liquid solution to be evenly distributed along the length of the top surface of the mesh material 203 and run down its surface. In some cases, this solution flow is essentially continuous. In some cases, the solution flow is pulsed at intervals to wet the mesh material, allowing hold-up and continued capture until subsequent pulses replenish the mesh material with fresh sorbent and flush the CO2-rich sorbent into a lower collection reservoir similar to one or more of the lower collection reservoirs 106 shown in FIG. 1.

[0207] In some implementations, the top bar 206 may comprise a tube or tubing with evenly spaced openings sized to allow capture solution to flow into the mesh material 203. For example, the top bar 206 may comprise a tube that is 1 / 16 inch in diameter with openings spaced 1 / 8 inch apart along the length of the tube. The tube or tubing may be configured to receive capture solution at one end and be capped with a "blank" or breather tube at the opposite end. The breather tube fills the tube with capture solution while venting air out of the tube. It may be advantageous to machine-form the openings to achieve greater precision compared to manually cut openings, as slight differences in size, angle, and spacing of the openings may affect the overall flow pattern in the mesh material 203.

[0208] 11 and 12 show another example of mesh packing 101 and liquid distribution system 1100, 1200, where one or more sheets of mesh material 203 are sewn across top support bar 206 and bottom support bar. The liquid distribution system 1100, 1200 may include one or more liquid delivery tubes or conduits 1150 for introducing a liquid solution into the top of the mesh packing 101. The sorbent may be distributed into a partially enclosed space consisting of one or more of the support beams 204, top support bar 206, and one or more liquid distribution facilitating devices (shown as distribution spacers 1140).

[0209] 11 and 12, one or more of the upper spacers can be combined with, for example, a perforated or mesh structural material to create a distribution spacer 1140 that, in addition to providing fixed spacing for the upper support bars 206, is configured to further promote uniform distribution of the sorbent across the mesh material 203.

[0210] In some cases, one or more of the distribution spacer 1140, the upper bar 206, and / or the support beams 204 are optimized to receive the liquid sorbent 124 directly from the delivery conduit (e.g., tube) 1150 and transfer the liquid sorbent 124 to the mesh material 203 without the use of nozzles, spray atomizers, or other commonly known components for liquid distribution across the packing.

[0211] FIG. 13 illustrates an exemplary integrated structural support system 1300. It may be advantageous to integrate the support system with the upper reservoir to save material costs by eliminating the need for a separate upper reservoir. The upper bars 206 and the distribution spacers 1140 may form at least a portion of the floor of the upper reservoir 1302. For example, the floor of the upper reservoir 1302 may include the upper bars 206 and the distribution spacers 1140 with intervening mesh panels 202 pressed together to form a portion or the entire floor of the upper reservoir 1302. The upper bars 206 and the distribution spacers 1140 may alternate with each other. In some implementations, the pattern of alternating upper bars 206 and distribution spacers 1140 may be different. For example, two upper bars 206 may alternate with one distribution spacer 1140. In some implementations, the gap between the upper bar 206 and the distribution spacer 1140 can be sized to achieve a particular liquid head in the upper sump 1302 (e.g., between 6 inches and 12 inches) or to achieve a particular solution flow rate of capture solution 124 at the mesh panel 202. This ensures that there is enough capture solution 124 available to wet the mesh panel 202.

[0212] The spacing or gap between the bars 206 can be selected to accommodate air velocities ranging from 0 m / s to 2.5 m / s while maintaining a relatively low pressure drop (e.g., less than 0.2 in. water column (in. WC)). In some cases, for systems using air velocities greater than 2.5 m / s, it may be advantageous for the mesh panel 202 to comprise a rigid or hard material to reduce damage or vibration. In some cases, the upper bars 206 can be spaced apart from one another by at least 1 inch.

[0213] The sides of the upper reservoir 1302 may be formed from a set of walls 1304 that are connected to the support beams, the upper bar 2066, and the distribution spacer 1140. The set of walls 1304 may be sealed against one or more of the upper bar 206 and / or the distribution spacer 1140, which may form at least a portion of the floor of the upper reservoir 1302, to reduce the amount of liquid bypass at the edges of the upper reservoir 1302. Thus, the edges where the sides of the upper reservoir 1302 abut the floor of the upper reservoir 1302 are at least partially sealed to reduce liquid bypass of the capture solution 124.

[0214] In some cases, at least a portion of the floor of the upper sump 1302 can eliminate the distribution spacer such that the floor is formed solely from the upper bars 206 pressed together. One or more mesh panels 202 can be positioned to interpose between the upper bars 206. The thickness of the mesh panels 202 between the upper bars 206 can define gaps or openings between the upper bars 206 that are large enough to allow the capture solution 124 to flow into the mesh panels 202. The gaps or openings between each of the upper bars 206, as defined by the thickness of the mesh panels 202, can be sized to achieve a particular solution flow rate (e.g., from 1 L / min to 4 L / min).

[0215] In some cases, the bottom portion of the support system may have a symmetrical configuration with the top portion. For example, at least a portion of the bottom reservoir may be formed from bottom bars pressed together with an intervening mesh material. In some implementations, the bottom portion of the support system may include bottom spacers between the bottom bars. The gaps or openings between the bottom bars, bottom spacers, or combinations thereof may be sized to allow sufficient airflow with relatively low pressure loss. A collection reservoir or bottom reservoir may be positioned below the support system to collect capture solution from the mesh packing.

[0216] 11 and 12, in some cases, the liquid sorbent 124 passes through the distribution spacer 1140 and spreads across the upper portion of the mesh material 203. The even distribution of the liquid sorbent across the mesh material 203 creates a thin film of solution that moves with gravity flow.

[0217] In some cases, a combination of gravity and the properties of the mesh material 203 itself will act to pull the solution down into a lower reservoir (e.g., bottom reservoir 106). The sorbent 124 reacts with the inlet CO2-laden air 220 and captures (absorbs into the capture solution) at least a portion of the CO2, and the resulting CO2 lean air flow 130 leaves the mesh packing 101.

[0218] In some cases, one or more of the upper bars 206 or distribution spacers 1140, or a combination thereof, may be configured to both evenly distribute the adsorbent 124 across the mesh packing 101 and maintain optimal spacing between the gas passages 408.

[0219] In some cases, the distribution spacer 1140 may be formed from multiple plastic tubes compressed at one end to form a tapered shape. The distribution spacer 1140 may be tapered in cross section from one end to the opposite end, allowing the distribution spacer 1140 to be more easily installed in a particular framework (e.g., a frame that is rounded or cylindrical).

[0220] In some cases, the liquid distribution system 1100, 1200 is configured to allow the flow of solution to be either essentially continuous or pulsed at intervals to wet the mesh material 203. In some cases, the pulsed flow allows sufficient hold-up and continued capture until a subsequent pulse replenishes the mesh material 203 with new sorbent and flushes the CO2-rich sorbent into a lower collection reservoir (such as bottom reservoir 106 shown in FIG. 1). In some cases, this configuration allows for a continuous but sufficiently smaller liquid flow rate, which also acts to reduce the associated liquid distribution capital and operating costs.

[0221] As discussed above, two broad wetting techniques, bridging and capillary action, are possible when using aqueous liquid capture sorbents and are dictated by the material properties of the fibers of the mesh material 203 making up the mesh packing 101. The bridging technique, described in more detail with reference to FIG. 14, occurs when the mesh material 203 is more hydrophobic in nature, resulting in a "bridging" of the solution between the fibers. The capillary action technique, described in more detail with reference to FIG. 15, occurs when the fibers of the mesh material 203 are more hydrophilic. Using the capillary action technique rather than bridging of the solution draws the solution along the fiber surfaces.

[0222] 14A-14C show diagrams of an exemplary hydrophobic mesh material 1400. FIG. 14A shows a diagram of an example wetted hydrophobic mesh material 1400 with mesh pores 1410 having a rectangular shape and defined by interconnected mesh fibers 1430. The mesh pores 1410 are open volumes. In one embodiment, referring to FIG. 14A, the mesh pores 1410 are openings formed in the mesh material 1400. Upon wetting, a liquid film 1425 forms in the mesh material 1400. The liquid film 1425 extends across and covers some or all of the mesh pores 1410, thereby "spanning" the mesh fibers 1430. Figure 14B shows a cross section (rotated 90 degrees from the perspective in Figure 14A) of an example of a liquid membrane 1425 spanning or stretching across a mesh aperture 1410 defined between vertically spaced circular top and bottom mesh fibers 1430 in a single square aperture 1410. Figure 14C shows an example of an aperture width W that is wide enough to overcome the properties of a given capture solution 124 such that a spanning membrane cannot be established between vertically adjacent mesh fibers 1430.

[0223] As mentioned above, the technique of bridging occurs when hydrophobic fibers 1430 provide liquid solution bridging between fibers 1430 to form a plurality of spanning membrane pores that collectively form liquid film 1425 (shown in FIG. 14B). The formation of liquid film 1425 may be due to minimization of the surface energy of liquid capture sorbent 124 at the interface of liquid 124 with the fibers 1430 of the packing combined with the surface tension of liquid capture sorbent 124. The dimensions of the spanning solution may be determined by the diameter of the fibers 1430, the spacing (width W of mesh pores 1410), the hydrophobicity of the fiber material, and the surface tension of the solution. The liquid film 1425 spanning the mesh pores 1410 defines a gas-liquid interface 1452 along which the CO2-containing air 220 is absorbed by the liquid capture solution 124. It may be desirable to maximize the height H of the gas-liquid interface 1452. A maximized gas-liquid interface 1452 can be achieved by optimization of the above parameters for a given capture solution composition, and the gas-liquid contactor operating parameters, and is desirable because a larger gas-liquid interface 1452 provides a larger available surface area for increased mass transfer of CO2 to the liquid capture sorbent 124. Referring to Figure 14B, in a wet mesh panel 1401 configuration where solution bridging occurs between the mesh fibers 1430, the height H of the gas-liquid interface 1452 is equal to or greater than the dimension between adjacent mesh fibers 1430 (e.g., width W in Figure 14B).

[0224] When using the bridge technique, referring to FIG. 14B, the surface of the hydrophobic mesh fibers 1430 themselves remain largely unwetted due to their own hydrophobic nature, and therefore do not contribute significantly to the gas-liquid interface 1452. Thus, an optimized hydrophobic mesh panel 1401 can maximize the gas-liquid interface 1452 by adjusting the fiber diameter (dictated in part by the structural integrity of the tensioned mesh panel 1401) and the spacing between the mesh fibers 1430 that define the mesh pores 1410. However, excessively large fiber spacing will result in the destruction of the adsorbent bridge (for a given solution surface tension), where the liquid bridge height H no longer spans the pore width H, as shown in FIG. 14C. Referring to FIG. 14C, in a configuration of a wet mesh panel 1401 where no bridging occurs between the mesh fibers 1430, the height H of the gas-liquid interface 1452 is less than the dimension between adjacent mesh fibers 1430 (e.g., the width W in FIG. 14C).

[0225] In some implementations, the hydrophobic material enhances droplet breakup and uniform liquid distribution is optimized for efficient CO2 capture from dilute gas concentrations. In some implementations, the hydrophobic properties of the mesh panel 1401 can create a relatively uniform liquid film 1425 across the mesh perforations 1410, generating a gas-liquid interface 1452 on either side of the mesh perforations 1410, as seen in FIG. 14B. Having a gas-liquid interface 1452 on either side of the mesh perforations 1410 can increase (e.g., double) the interface surface area of ​​the liquid sorbent 124 that is available to absorb CO2 from the CO2-laden air 120, improving the efficiency of the mesh panel 1401 in capturing CO2.

[0226] In some implementations, PVC coated fiberglass, plastic, or metal materials are used to create a woven, twill, basket, or herringbone pattern for the mesh material, which may have a hydrophobic wetting technique.

[0227] 15A-15C depict an exemplary hydrophilic mesh material 1500. FIG. 15A shows a view of an example of a wetted hydrophilic mesh material 1500 with mesh pores 1510 surrounded or defined by rectangular mesh fibers 1530 as capture solution flows down to form a liquid film 1535. FIG. 15B depicts the same hydrophilic mesh material 1500 without liquid solution flowing down the surface of the mesh material 1500. The capture solution sits on the surface of the mesh fibers 1530 to form a partial or complete liquid film 1535. FIG. 15C shows a cross section of an example of a liquid capture solution forming a liquid film 1535 flowing along the mesh fibers 1530 of the mesh material 1500 in FIG. 15A (rotated 90 degrees from the perspective in FIG. 15A).

[0228] The capillary wetting technique occurs when the mesh fibers 1530 are inherently hydrophilic or are adapted to be hydrophilic. In some cases, capillary action draws the solution along the surface of the mesh fibers 1530 rather than bridging the solution. The gas-liquid interface 1552 will then be determined by the area of ​​the wetted fibers 1530 and the thickness of the liquid sorbent layer 1535, which in turn will be determined by the hydrophilicity of the fiber material and the flow rate 1551 of the liquid sorbent down the mesh material 1500. When using this capillary technique, the mesh pores 1510 may or may not be completely wetted depending on the thickness of the liquid sorbent layer and the fiber spacing of the packing. Therefore, optimization of a more hydrophilic mesh material 1500 (using the capillary technique) will be different from optimization of a more hydrophobic mesh material 1400 (using the bridging technique). Nonetheless, it will be appreciated that solution bridging of the mesh pores 1510 can occur even when capillary action techniques are the predominant mode of wetting for the mesh material 1500, such as in the example of a mesh material 1500 that is completely saturated with liquid sorbent, or in the example of a large liquid sorbent flow rate 1551 that floods the mesh material 1500. For example, with reference to Figure 15A, a wetted hydrophilic mesh material 1500 includes a liquid film 1535 (i.e., solution bridging) that spans the mesh pores 1510, and also the surfaces of the mesh fibers 1530 that are wetted through capillary action.

[0229] 15C, a gas-liquid interface 1552 is formed on the wetted outer surface of the interconnecting mesh fibers 1531 along their length and also on the wetted periphery of the other illustrated mesh fibers 1530 that have an orientation that is transverse to the orientation of the interconnecting mesh fibers 1531. Referring to FIG. 15C, the CO2 capture solution 124 flows along the outer surface of the hydrophilic mesh fibers 1530. Having a gas-liquid interface 1552 on many exposed surfaces of the wetted mesh material 1500 can provide increased surface area of ​​the liquid sorbent 124 available to absorb CO2 from the inlet CO2-laden air 120, improving the efficiency of the mesh panel 1500 in capturing CO2. In the configuration of the wetted mesh material 1500 of FIG. 15C, a single surface of the mesh fibers 1530, the exposed outer surface, is available to receive the liquid sorbent 124 to form the gas-liquid interface 1552.

[0230] In some implementations, a nonwoven mesh material 1500 made of nylon, metal, organic fabrics such as burlap, hemp, or cellulose, or a combination of similar materials may have a hydrophilic mechanism of wetting. A nonwoven material may include, but is not limited to, any material that is not interwoven in a regular pattern. This may include any interwoven organic or synthetic fabric such as felt (burlap explicitly woven in), or a single sheet of material with perforations, holes, or inherent wicking characteristics. A nonwoven material may be made of an ordered mesh of fibers that do not interact through a weave pattern, but rather are bonded together through some other manner, either mechanically or chemically (e.g., through adhesives, solvent bonding, or other means).

[0231] In some cases, hydrophilic design can improve the wetting of the mesh packing 101 by the capture solution. Improved wetting of mesh material 1500 with hydrophilic properties (e.g., increasing the wetted surface area of ​​mesh material 1500) can be achieved by at least two approaches. The first approach is to increase the hydrophilicity of the surface of mesh material 1500 by increasing the surface free energy, which is a property of the material of mesh material 1500. The second approach is to increase the surface roughness and apparent contact angle of mesh material 1500. These approaches can be used independently or in combination with each other.

[0232] A hydrophilic material can be included in the mesh packing 101 for gas-liquid contactor applications because the wetted surface area determines the amount of exposure of the capture solution to the CO2 in the air, and a hydrophilic material surface maximizes the wetted area for a given volume of solution. In some cases, hydrophilicity can be built into the mesh material 1500 when fabricated, or can be introduced as a coating after fabrication. The hydrophilic coating increases the surface energy and reduces the contact angle. In some cases, some surface treatments that expose the material to changes in the bonds of the material's surface can achieve similar hydrophilic results.

[0233] In an exemplary implementation, the hydrophilic mesh material 1500 may include a coating applied to the mesh fibers 1530 to increase hydrophilicity. In some cases, the hydrophilic coating on the mesh material 1500 is fully wetted with minimal solution flow. This can result in higher capture rates while significantly reducing solution flow.

[0234] 15A, in some implementations, the hydrophilic mesh material 1500 is wetted with the capture solution, soaking the hydrophilic material until the mass / volume of the liquid exceeds a threshold saturation level of the hydrophilic mesh material 1500 to create a liquid film 1535 within the mesh pores 1510 in addition to the wetted surface of the hydrophilic mesh material 1500 itself, forming droplets that flow along the mesh fibers 1530 and into the mesh pores 1510. This differs from the hydrophobic wetting technique of FIGS. 14A-14C, which relies on the mesh material to repel the liquid, forcing the droplets away from the mesh fibers 1430 and into the mesh pores 1410.

[0235] In some implementations, the mesh material 1500 can include material additives to further optimize hydrophilicity and reduce the contact angle between liquid-solid interfaces in at least a portion of the mesh material 1500.

[0236] In addition or as an alternative to the previous examples of hydrophilic mesh materials, the roughness of the mesh fiber surface may be altered to increase hydrophilicity.

[0237] In some implementations, the mesh material 1500 includes at least a portion that has hydrophilic properties. In some cases, this can increase the CO2 capture flux (e.g., at least 10%) through an increase in the wetting ratio of the mesh material 1500.

[0238] In some implementations, the mesh material 1500 includes at least one portion having hydrophilic properties and at least one other portion having hydrophobic properties. Thus, in one embodiment, the mesh material 1500 can have both hydrophilic and hydrophobic properties. In some implementations, the hydrophilic mesh material 1500 can be used as a drift eliminator in a gas-liquid contactor to mitigate the release of droplets of captured solution into the environment. The hydrophilic nature of the mesh material 1500 in the drift eliminator can attract droplets of captured solution into the mesh fibers to prevent the droplets from flowing downstream.

[0239] In both the hydrophobic and hydrophilic mesh material wetting techniques, reducing the amount of mesh material required can be achieved by utilizing liquid surface tension properties to achieve a high ratio of gas-liquid interface area to mass of material. Based on a given liquid solution surface tension, a film of sorbent solution can span the mesh pores, providing a total reactive gas-liquid interface area that is greater than the surface area of ​​the mesh packing alone. In these cases, the wetting ratio ε, defined as the ratio of liquid surface area per mesh material surface area (excluding mesh pore area), is greater than 100%. Thus, when the mesh material is wetted and solution spans the open mesh pores 1410, the gas-liquid interface area is greater than the total surface area of ​​the mesh fibers 1430. Furthermore, the openness of the mesh pores 1410 coupled with the solution span provides interface area on both sides of the wetted mesh panel 1401. This contrasts with the surfaces of some standard heat exchange packings or structured packings in that a uniform air-liquid film interface is formed on both sides of the surface of the mesh packing 101 disclosed herein. In some cases, the mesh material can be thought of as an internal support for a nearly uniform liquid film.

[0240] Both hydrophobic and hydrophilic wetting techniques can be used with the mesh material to produce a mesh packing 101 with lower pressure drop, optimal CO2 capture efficiency, and lower capital and operating costs. Also, when configured as described in this disclosure, a sheet of mesh material that can be produced with either of these wetting techniques can have lower pressure drop, reduced air travel depth, and reduced overall gas and liquid energy consumption. Although these two techniques use slightly different characteristics to achieve results, both techniques can be configured to produce a sheet of mesh material with the desired performance.

[0241] In a typical mesh packing design, the mesh fiber diameter may range from 0.001 inch to 0.5 inch, with mesh fiber spacing ranging from 0.001 inch to 0.5 inch.

[0242] In some implementations, the mesh material 1400, 1500 is selected to be a material that is compatible with the CO2 capture solution, for example, a high pH solution or a hydroxide solution such as KOH, NaOH, or carbonate / bicarbonate solutions. The optimal range of sorbent concentration will depend on the operating and environmental conditions. In some cases where the capture solution includes a sorbent such as NaOH, KOH, the solution may have an optimal range of hydroxide solution. For example, the optimal hydroxide solution concentration may range from 0.5M to the saturation point of the hydroxide solution under a given operating condition (e.g., temperature), at which additional CO2 may be absorbed. Similarly, for other sorbents, the optimal sorbent concentration may range from 0.5M to the saturation point of the sorbent.

[0243] 16A-16C are front, side, and plan views of an exemplary mesh packing 101 and support system testing device 1600. Testing device 1600 is similar to the support systems described above (such as support system 800 of FIG. 8A) in that it includes one or more top bars 206, one or more bottom bars 208, one or more support columns 214, one or more support beams 204, one or more upper spacers 1140, one or more lower spacers 212, and one or more mesh panels 202. FIG. 16A shows sewn mesh panels (fabric) 202 alternating between offset top bars 206 and bottom bars 208.

[0244] In some cases, an example of the shape of the gas passage 408 formed by the mesh panel 202 in the test device 1600 is rectangular as shown in FIG. 16B. In some cases, the shape of the passage 408 can be triangular, circular, or rectangular. The shape of the gas passage 408 can be selected based on the given surface tension, the flow pattern of the absorbent, the size of the mesh material surface, the reactive gas-liquid interface area, and the liquid sorbent performance on top of the mesh packing of the passage. In some cases, the space between the mesh panels 202 (gas passage width 207) is less than 6 inches, allowing for uniform distribution of the sorbent on both sides of the mesh material surface. In some cases, the gas passage 408 can be positioned at an angle determined by the spacing between the top bar 206 and the bottom bar 208 in combination with the stitching pattern of the mesh panel 202.

[0245] The testing device 1600 shown in Figures 16A-16C, in combination with the mathematical equations set forth below, can be used to evaluate the performance of mesh packing 101. The experimental testing conditions and results of tests conducted using the testing device 1600 are described in more detail below, and preliminary test results are shown in Figure 17.

[0246] FIG. 17 shows the effective mass transfer coefficient K versus air velocity for various sorbent loading rates using an aqueous KOH capture solution over the air travel depth (ATD) of the mesh packing 101 mounted in the test device 1600 shown in FIGS. 16A-16C. eff 17 shows a graph 1700 illustrating the above.

[0247] A mesh packing sample was tested in a laboratory-scale gas-liquid contactor. The packing was 200 m 2The tests were conducted under ambient air conditions (temperatures ranging from approximately 5°C to 15°C, and a CO2 inlet concentration of approximately 400 ppm) with air velocities ranging from 1.0 to 2.5 m / s, using an aqueous solution of KOH as the trapping sorbent. The same concentration of KOH trapping sorbent was used for all tests. During the tests, the inlet and outlet CO2 concentrations were measured and subsequently analyzed using the method outlined below. eff was calculated for the given inlet area and ATD. The other constants are readily available in laboratory textbooks: the ideal gas constant has a value of 8.314, and the molar mass of CO2 is 44.01 kg / kmol.

[0248] Calculate the molar air and CO2 flow rates as follows:

[0249]

number

[0250] Calculate the CO2 mass flux as follows:

[0251]

number

[0252] Calculate the effective mass transfer coefficient as follows:

[0253]

number

[0254] In standard testing, a sample of each read was taken at each set point to develop a large sample pool and use statistics to address any measurement precision issues. From this data set, an average 95% confidence interval (CI) was determined and used to statistically test for differences in packing performance.

[0255] This preliminary evaluation of mesh packing has demonstrated empirically measured effective mass transfer coefficients in the range of approximately 1.0-2.0 mm / s for early prototypes, which are deemed sufficient for the economical design of CO2 capture gas-liquid contactors. Furthermore, testing reveals that mesh packing exhibits improved (higher) mass transfer coefficients with respect to published data for conventional packings (e.g., cooling tower packings), providing effective mass transfer coefficients closer to the 2 mm / s target known to be economically advantageous for large-scale DAC applications.

[0256] 18A and 18B depict an example of a molded mesh material 1800. The molded mesh material 1800 can be in the form of a sheet or panel and can include a plurality of protruding portions 1804 that collectively form the texture or topography of the molded mesh material 1800 and extend outwardly from a planar portion 1806 of the molded mesh material 1800. The planar portions 1806 define parallel planes and the protruding portions 1804 extend outwardly from the parallel planes into the airflow between adjacent mesh panels. In some implementations, the molded mesh material 1800 can increase the interface surface area by enhancing the bridging or capillary effect of the mesh material with improved wetting effects resulting from changes in the surface topography of the mesh material. As well as increasing the mesh material surface roughness (e.g., by increasing the mesh fiber coarseness) to reduce the liquid contact angle, flat sheets of mesh material can be molded, pressed, shaped, warped, or formed to affect the flow pattern of the capture solution. Given that the molded mesh material 1800 defines gas passages, this does not create a significant impediment to airflow, as the spacing of the gas passages can be selected to accommodate airflow, and the pores that have no liquid film or only partially have a liquid film allow air to pass through. Taking into account the gas passage spacing, the protrusions 1804 can be shaped to minimize the restriction to airflow in the gas passages and minimize pressure loss across the mesh packing. In some cases, the molded mesh material 1800 can be suitable to be used as a mist eliminator downstream of the packing of the gas-liquid contactor. The protruding portions 1804 can impinge on the moving droplets of capture solution so that they are not released into the environment.

[0257] 18A depicts an example of a molded mesh material 1800 in which the protruding portions 1804 include rounded projections or ridges that extend outward from a planar portion 1806 of the mesh material 1800 (an area of ​​the mesh material 1800 that is a planar surface). Although the rounded projections 1804 are shown as being generally uniformly sized and evenly spaced, in some cases it may be beneficial to vary the size, spacing, shape, and number of the protruding portions 1804 to affect solution flow. For example, if a flat sheet of mesh material has dry or dead spots that are difficult to wet with capture solution, an area of ​​the mesh material adjacent to the dry or dead spots can be molded to include rounded protruding portions 1804 to promote solution flow to the dry or dead spots.

[0258] Figure 18B shows another example of a molded mesh material 1800 in which protruding portions 1804 include ridges, folds, or corrugations. The protruding portions 1804 in Figure 18B are planar, defining a plane that is oblique or non-parallel to the plane defined by the planar portion 1806 of the mesh material 1800. These ridges, folds, or corrugations can be sized and positioned to affect solution flow.

[0259] 18A and 18B show rounded projections and ridges as exemplary textures, but various other shapes are possible, including herringbone, corrugations, grooves, or channels. In some cases, the molded mesh material 1800 may include a sheet of mesh material molded to mimic the pattern of a sheet or panel of conventional rigid packing in structured areas. In some cases, the molded mesh material 1800 may be molded to form a texture or structure that allows areas of the mesh packing to interlock with one another (e.g., via a plug receiving structure). The molded mesh material 1800 may be formed from a flexible mesh material that is easily installed on the support system described above, or a support system that allows the molded mesh material 1800 to hang freely from an upper support bar. In some implementations, the molded mesh material 1800 may be formed from a rigid mesh material with a thicker or stiffer weave that allows the molded mesh material 1800 to be self-supporting. Adjacent sheets or panels of molded mesh material 1800 can have the same shape and can be spaced apart from one another to define gas passages 408 that have consistent gas passage width / height along the ATD. In another possible implementation, adjacent sheets / panels of molded mesh material 1800 can have different shapes and can be spaced apart from one another to define gas passages 408 that converge, are interleaved along the ATD, or diverge from one another along the ATD.

[0260] 19 depicts an example flow pattern 1900 of CO2 capture solution 1909 at varying solution flow rates in mesh material 1902. When CO2 capture solution 1909 is dispensed into dry mesh material 1902, at a particular solution flow rate, the CO2 capture solution 1909 can form a serpentine flow 1911, indicating that the mesh material 1902 is fully wetted or saturated. As the serpentine flow 1911 of CO2 capture solution 1909 flows down the mesh material 1902, the serpentine flow 1911 will also flow laterally in a direction transverse to the downward flow direction in the mesh material 1902. The serpentine flow 1911 may travel laterally across the mesh material 1902 in a winding or serpentine path (e.g., from one side of the mesh material 1902 to the other and back) as the CO2 capture solution 1909 flows down the mesh material 1902. The serpentine flow 1911 typically appears when there is an underlayer of CO2 capture solution 1909 on the mesh material 1902. Thus, a wide, winding path of the serpentine flow 1911 indicates that a significant portion of the mesh material 1902 has been wetted, and the serpentine flow 1911 maintains the flow of CO2 capture solution 1909 in the wetted portions. For example, in the mesh material 1902, at low flow rates (e.g., approximately 1 L / min), the flow pattern 1904 may include multiple flows that are relatively straight and uniformly spaced from each other (e.g., by 0.2 inches to 2 inches). At twice the small flow rate (e.g., approximately 2 L / min), flow pattern 1906 may include one or more streams having a slightly tortuous flow path along mesh material 1902. At three times the small flow rate (e.g., approximately 3 L / min), one or more streams may merge, resulting in flow pattern 1908 including at least one stream that meanders more than the streams in flow pattern 1906 at twice the small flow rate, thereby forming a meandering stream 1911 that wets a larger area of ​​mesh material 1902.At four times the low flow rate (e.g., approximately 4 L / min), a substantial portion of the mesh material 1902 is flooded by at least one serpentine flow 1911 of flow pattern 1910 that is wider than the flow of flow pattern 1906 at twice the low flow rate. At four times the low flow rate, the CO2 capture solution 1909 of flow pattern 1910 takes a wider path than at two or three times the low flow rate, thereby wetting a larger surface of the mesh material 1902. The serpentine flow 1911 typically indicates that the portion of the mesh material covered by the flow path is fully saturated with CO2 capture solution 1909. In some cases, the serpentine flow 1911 of flow patterns 1908, 1910 can proceed laterally across the width of the mesh material 1902, thereby increasing wetting compared to flow patterns 1904, 1906 at the lower flow rates. In some implementations, in a flow cycle where the CO2 capture solution 1909 flows into the mesh material 1902 at a small pulse flow rate (or zero flow) for a first time period and a large flush flow rate for a second time period, the large flow rate can be three or four times the small / pulse flow rate. In some implementations, in a flow cycle, the CO2 capture solution 1909 does not flow into the mesh material 1902 for a first time period and flows into the mesh material 1902 at a solution flow rate in the range between 1 L / min and 2 L / min for a second time period. The thickness and direction of the serpentine flow 1911 depends on the flow rate of the CO2 capture solution 1909, but in some cases may also be influenced by a combination of other factors, including tension in the mesh material 1902, surface tension of the CO2 capture solution 1909, and the hydrophobicity or hydrophilicity of the mesh material 1902.

[0261] 20, the mesh panels 2002 of the mesh packing 2001 may be oriented with respect to the CO2-containing air 120 to improve wetting of the mesh material 2003. In the configuration of the mesh packing 2001 of FIG. 20, each of the mesh panels 2002 has an upright orientation and a leading edge 2005 toward the CO2-containing air 120. The leading edge 2005 is the portion of the mesh panel 2002 positioned most upstream with respect to the flow of the CO2-containing air 120. The leading edge 2005 of one or more of the mesh panels 2002 is inclined at an angle θ with respect to the vertical in the downstream direction. The angle θ has a degree greater than zero. For upright mesh panels without an inclined leading edge, the CO2 capture solution introduced at or near the top of the leading edge may be displaced laterally by the CO2-containing air along the mesh material toward the CO2-containing air, especially for high flow velocities of the CO2-containing air, so that the lower portion of the mesh material adjacent to the leading edge may not be properly wetted. In contrast, a leading edge 2005 that is angled downwardly relative to the vertical can adequately wet the lower portion 2013 of the mesh material 2003 adjacent the leading edge 2005 when the CO2 capturing solution 124 is introduced at or near the top of the leading edge 2005, even for high flow velocities of CO2-containing air 120. Thus, the angled leading edge 2005 of the mesh panel 2002 can adequately wet all portions of the mesh material 2003 with the CO2 capturing solution 124.

[0262] Referring to FIG. 21, a gas-liquid contactor 2111 with mesh packing is part of a direct air capture (DAC) facility 2100 for capturing CO2 directly from the atmosphere, according to one possible non-limiting example of a use for the gas-liquid contactor 2111. The gas-liquid contactor 2111 absorbs a portion of the CO2 from the atmosphere 2103 using the CO2 capture solution 124 to form a CO2 rich solution 2102. The CO2 rich solution 2102 flows from the gas-liquid contactor 2111 to a pellet reactor 2110 of the DAC facility 2100. A slurry of calcium hydroxide 2104 is injected into the pellet reactor 2110. Ca 2+CO3 in pellet reactor 2110 2- When reacting with CO2, this drives the decomposition of calcium hydroxide, returning the aqueous alkaline solution stream as CO2 capture solution 124 and depositing calcium carbonate (CaCO3) into calcium carbonate particles in the pellet reactor 2110. Further processing of the calcium carbonate solids, including but not limited to filtering, dewatering, or drying, may occur before sending the calcium carbonate solids to downstream process units. A calcium carbonate solids stream 2106 is transported from the pellet reactor 2110 to a calciner 2120 of the DAC facility 2100. The calciner 2120 calcines the calcium carbonate of the stream 2106 from the pellet reactor 2110 to produce a stream of gaseous CO2 2108 and a stream of calcium oxide (CaO) 2101, possibly by oxy-combustion of the calciner 2120 fuel source. The gaseous CO2 2108 stream is treated for sequestration or other use, thereby removing a portion of the CO2 from the air 2103 treated in the gas-liquid contactor 2111. The calcium oxide (CaO) 2101 stream is slaked with water in a digester 2130 of the DAC facility 2100 to produce a slurry of calcium hydroxide 2104 that is provided to the pellet reactor 2110.

[0263] FIG. 22 shows a schematic diagram of an exemplary gas-liquid contactor 2200. The gas-liquid contactor 2200 comprises a housing 2204 having a plurality of housing walls 2209 that define an interior of the housing 2204. The gas-liquid contactor 2200 comprises a mesh packing 2201. The mesh packing 2201 comprises a single mesh panel 2202 having a mesh material 2203. Two gas passages 2208 are formed in the interior of the housing 2204. Each gas passage 2208 is formed on one side of the mesh panel 2202 between the mesh panel 2202 and the one or more housing walls 2209. The single mesh panel 2202 in FIG. 22 has an upright orientation. In another possible implementation of the gas-liquid contactor 2200, the single mesh panel 2202 has a horizontal orientation. In another possible implementation of the gas-liquid contactor 2200, the single mesh panel 2202 has an inclined orientation relative to the orientation of the vertical or horizontal plane.

[0264] 23 shows a schematic diagram of an exemplary gas-liquid contactor 2300 as viewed from an end of the gas-liquid contactor 2300. The gas-liquid contactor 2300 comprises a cylindrical housing 2304 having a housing wall 2309 that defines an interior of the housing 2304. The gas-liquid contactor 2300 comprises a mesh packing 2301. The mesh packing 2301 comprises a mesh panel 2302 having a mesh material 2303. The mesh panel 2302 is positioned within the housing against the housing wall 2309. A single gas passageway 2308 is formed within the housing 2304. The gas passageway 2308 is formed on one side of the mesh panel 2302 and is generally defined by the mesh panel 2302. The mesh panel 2302 may be a cylinder defined about a central axis. The orientation of the central axis may be upright, horizontal, or at an angle between upright and horizontal. The mesh panel 2302 of Figure 23 is a single piece or a continuous piece. In another possible implementation, the mesh panel 2302 is an assembly of circumferentially extending or arcuate panel sections that are attached to the housing wall 2309 and / or to each other. With reference to Figure 23, the first dimension is the diameter measured between diametrically opposed points of the mesh panel 2302.

[0265] It will be apparent to one of ordinary skill in the art that further modifications to the specific details disclosed herein can be made, resulting in other embodiments that are within the scope of the present disclosure. All parameters, dimensions, materials, and configurations described herein are merely examples and can vary depending on the particular embodiment. [Explanation of symbols]

[0266] 100 Gas-liquid contactor, gas-liquid contactor system 101 Mesh Packing 102 Blower 103 Fan air guide plate 104 Case 105 Frames 106 Bottom liquid collection reservoir 107 Upper distribution liquid reservoir 109 Liquid Distribution Systems 110 Air inlet 114 Plenum 120 CO2-containing air, CO2-containing air flow 124 CO2 capture solution, CO2 concentrated capture solution, capture solution, liquid adsorbent, adsorbent, liquid capture adsorbent, liquid, liquid capture solution 130 CO2 thin air flow 200 Gas-liquid contactor system, gas-liquid contactor 202, 202a, 202b Mesh panels 203 Mesh Material 204 Support beam, beam 206 Bar, upper bar, upper support bar 207 Gas passage interval, gas passage width 208 Bar, bottom bar, bottom support bar, lower support bar 209 Mesh Panel Section 210 Upper spacer, spacer 212 Lower spacer, spacer 214 Support column 215 Mooring Position 220 CO2-containing air flow, CO2-containing gas flow, CO2-containing air 230 CO2 thin air flow 300 Gas-liquid contactor system, gas-liquid contactor 400 Gas-liquid contactor 401 Structural Support Systems 408 Gas passage 500 Structural Support System 700 Bar design 702 Grooved bar material 703 Groove 704 Upper bar 706 Tapered bar material 708 Upper bar 800 Structural support systems, support systems 801 Mesh Packing 802 Mesh Panel 900 Structural Support System 901 Mesh sheet 999 Control Systems, Flow Control Systems 1000 Structural support system, support system 1100 Liquid Distribution System 1140 Distribution spacer, upper spacer 1150 Liquid delivery tube, delivery conduit 1200 Liquid Distribution System 1300 Structural Support System 1302 Upper liquid reservoir 1304 Wall 1400 Hydrophobic mesh material, mesh material 1401 Mesh Panel 1410 Mesh small hole 1425 Liquid film 1430 Mesh fiber, hydrophobic fiber, fiber 1452 Gas-liquid interface 1500 Hydrophilic mesh material, mesh material 1510 Mesh small hole 1530 Hydrophilic mesh fiber 1531 Interconnecting mesh fibers 1535 Liquid membrane, liquid adsorbent layer 1551 Liquid sorbent flow rate 1552 Gas-liquid interface 1600 Test Devices 1700 graphs 1800 Mesh Material 1804 Protruding parts, rounded protrusions 1806 Planar part 1900 Flow Pattern 1902 Mesh material 1904 Flow Pattern 1906 Flow Pattern 1908 Flow Pattern 1909 CO2 capture solution 1910 Flow Pattern 1911 Meandering Stream 2001 Mesh packing 2002 Mesh Panel 2003 Mesh material 2005 Leading Edge 2013 lower part 2100 Direct Air Capture (DAC) Facility 2101 Calcium oxide (CaO) 2102 Concentrated solution of CO2 2103 Atmosphere 2104 Calcium hydroxide 2106 Flow 2108 CO2 gas 2110 Pellet Reactor 2111 Gas-liquid contactor 2120 Calciner 2130 Digestion machine 2200 Gas-liquid contactor 2201 Mesh Packing 2202 Mesh Panel 2203 Mesh material 2204 Case 2208 Gas passage 2209 Enclosure wall 2300 Gas-liquid contactor 2301 Mesh Packing 2302 Mesh Panel 2303 Mesh Panel 2304 Case 2308 Gas passage 2309 Enclosure wall ATD Air advance depth D1 First direction H Height W Small hole width θ angle

Claims

1. Carbon dioxide (CO) from a dilution gas source ２ 1. A gas-liquid contactor for capturing urea, comprising: a housing at least partially enclosing a plenum having an inlet and an outlet; at least one packing supported in the housing downstream of the inlet, the at least one panel comprising a mesh material and defining a gas passageway having a first dimension defined along a first direction and a second dimension defined along a second direction different from the first direction; The mesh material is ２ A liquid distribution system configured to wet the CO2 captured through the mesh material with a capture solution. ２ a liquid dispensing system comprising one or more reservoirs configured to hold a capture solution; CO ２ The contained gas is then immersed in the CO ２ The CO ２ a gas moving device configured to flow contained gas from the dilution gas source through the gas passage in the second direction; A gas-liquid contactor comprising:

2. 10. The gas-liquid contactor of claim 1, further comprising a drift eliminator coupled to said housing and positioned downstream of said at least one packing.

3. The gas moving device is a fan disposed downstream of the at least one packing at the outlet, the fan moving the CO ２ 3. The gas-liquid contactor of claim 2, rotatable about a fan axis to draw contained gas in said second direction through said gas passages and into said inlet.

4. The liquid distribution system is configured to wet the mesh material, and the wetted mesh material is then irrigated with the CO ２ A gas-liquid contactor according to any one of claims 1 to 3, wherein a liquid film of capture solution is formed on the mesh material.

5. The liquid distribution system includes ２ 4. The gas-liquid contactor of any one of claims 1 to 3, configured to flow the capture solution at a solution flow rate in the range of from 1 L / min to 4 L / min.

6. 4. The gas-liquid contactor of claim 1, further comprising a structural support supported by the housing and configured to support the at least one packing, the structural support comprising one or more support rods attached to one or more support beams.

7. 7. The gas-liquid contactor of claim 6, wherein the mesh material is fixedly attached to the one or more support bars by at least one of stitching, tensioning, or fasteners.

8. The liquid distribution system includes ２ 7. The gas-liquid contactor of claim 6, comprising one or more distribution facilitating devices configured to provide capture solution to at least a portion of the mesh material.

9. The gas-liquid contactor of claim 8 , wherein the one or more distribution facilitating devices comprise at least one of a liquid distribution rod or a liquid distribution spacer.

10. The gas-liquid contactor of claim 9, wherein one or more of the liquid distribution spacers comprises at least one tube having a tapered end.

11. 10. The gas-liquid contactor of claim 9, wherein the liquid distribution bar comprises a plurality of channels operable to flow the capture solution.

12. 10. The gas-liquid contactor of claim 9, wherein one or more of said liquid distribution spacers are pressed against one or more of said liquid distribution rods to form at least a portion of an upper liquid reservoir.

13. 10. The gas-liquid contactor of claim 9, wherein one or more of said liquid distribution rods and one or more of said liquid distribution spacers are integrally formed with said mesh material.

14. 10. The gas-liquid contactor of claim 9, wherein one or more of said liquid distribution rods, one or more of said liquid distribution spacers, and said at least one panel comprise a fiberglass core at least partially covered with a PVC covering.

15. The gas-liquid contactor of claim 6 , wherein a first support rod of the one or more support rods is configured to interlock with a second support rod of the one or more support rods.

16. The gas-liquid contactor of claim 6, wherein the one or more support bars comprise a cross-section that is C-shaped or arcuate.

17. 7. The gas-liquid contactor of claim 6, wherein the one or more support rods each have a thickness that tapers from a first end of the respective support rod to a second end of the respective support rod.

18. The one or more liquid reservoirs include: at least one upper reservoir positioned above the at least one panel; at least one bottom sump positioned below said at least one panel; Equipped with The liquid distribution system includes ２ 4. The gas-liquid contactor of any one of claims 1 to 3, configured to allow at least a portion of a capture solution to flow from said at least one bottom reservoir to said at least one upper reservoir.

19. 4. The gas-liquid contactor of any one of claims 1 to 3, wherein the gas-liquid contactor is configured to operate as part of a cooling tower system, a direct air capture air contacting system, or a combination thereof.

20. 4. The gas-liquid contactor of claim 1, further comprising a structural support supported by the housing and configured to support the at least one packing, the structural support comprising one or more support bars, a first subset of bars of the one or more support bars being offset from a second subset of bars of the one or more support bars, the second subset of bars being spaced apart from the first subset of bars in a direction perpendicular to the first and second dimensions, the mesh material comprising a continuous sheet of mesh material tensioned around the first subset of bars and the second subset of bars to form a plurality of panel sections, the plurality of panel sections extending between the spaced apart bars of the first subset of bars and the second subset of bars.

21. 21. The gas-liquid contactor of claim 20, wherein adjacent panel sections of the plurality of panel sections are spaced apart from one another in the first direction to define the gas passageway, and wherein the first dimension decreases in a direction parallel to a distance between the first subset of rods and the second subset of rods.

22. The gas-liquid contactor of claim 20, wherein adjacent panel sections of the plurality of panel sections have a non-parallel orientation relative to one another.

23. 4. The gas-liquid contactor of claim 1, further comprising a structural support supported by the housing and configured to support the at least one mesh packing, the structural support comprising one or more support rods, the mesh material being suspended from the one or more support rods.

24. 24. The gas-liquid contactor of claim 23, further comprising one or more spacers, each spacer of said one or more spacers being interposed between adjacent ones of said one or more support rods.

25. The gas-liquid contactor of claim 24, wherein the one or more spacers comprise one or more distributed spacers.

26. 26. The gas-liquid contactor of claim 25, further comprising one or more dispensing facilitation devices.

27. 27. The gas-liquid contactor of claim 26, wherein said one or more distribution facilitating devices comprise at least one of a distribution support rod or a distribution spacer.

28. The gas-liquid contactor of claim 24, wherein the one or more spacers comprise at least one tube having a tapered end.

29. The liquid distribution system includes ２ 4. The gas-liquid contactor of claim 1, further comprising one or more flow devices configured to flow a capture solution across the at least one packing, the one or more flow devices comprising at least one of a nozzle, a spray atomizer, or a liquid distribution bar.

30. the at least one packing comprises two packings spaced apart from each other laterally within the housing; The gas transfer device includes a fan disposed laterally between and downstream of the two packings at the outlet, the fan being adapted to move the CO ２ for drawing contained gas from said dilution gas source through said two packings, and for drawing CO 2 through said outlet. ２ 4. The gas-liquid contactor of claim 1, 2 or 3, which is rotatable about an upright fan axis to output a lean gas of 0.1 to 0.5 mm.

31. 4. The gas-liquid contactor of any one of claims 1 to 3, wherein the at least one panel defines a planar surface having a vector perpendicular to the planar surface, the vector having a horizontal orientation.

32. The at least one panel has an upright orientation, and the CO ２ a leading edge defined relative to the flow of contained gas, the leading edge being ２ 4. A gas-liquid contactor according to any one of claims 1 to 3, which is inclined in the direction of flow of contained gas and which subtends an angle with respect to the vertical axis.

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