Integrated rotating packed bed adsorber, cooler, and amine entrainment unit

Abstract

Systems and methods are provided for performing amine capture on a heated flue gas using multiple rotating packed beds. By integrating a series of rotating packed beds to perform cooling of the flue gas, removal of CO2 from the flue gas by contact with an aqueous amine, and washing of the gaseous effluent from CO2 removal step to remove any entrained amine, the equipment footprint and overall equipment volume required for CO2 capture can be significantly reduced. The integration of cooling, CO2 removal, and washing can be integrated into a series of packed beds in part by using different packing materials in the various packed beds.

Description

INTEGRATED ROTATING PACKED BED ADSORBER, COOLER, AND AMINE ENTRAINMENT UNITFIELD OF THE INVENTION

[0001] Integrated rotary bed systems are provided for cooling of a gas stream, removal of CO2 from the gas stream via contact with a liquid amine stream, and removal of entrained amine from the resulting CO2-depleted stream. Corresponding methods are also provided.BACKGROUND OF THE INVENTION

[0002] Capture and sequestration of CO2 can contribute to efforts for reducing or minimizing the amount of CO2 introduced into the atmosphere by various commercial, residential, and / or industrial processes. One conventional technology for capturing CO2 is to contact a CO2- containing gas stream (such as a flue gas) with an aqueous amine stream. This can adsorb the CO2 from the gas stream with high efficiency. As CO2 capture becomes an increasingly important technology, additional improvements in using aqueous amine streams for CO2 capture would be desirable.

[0003] International Publication WO / 2015 / 060723 describes a system for adsorption and desorption of CO2 that involves the use of a single rotating wheel with an adsorption layer. In addition to the rotating packed wheel with the adsorption layer, a demister section and a wash section are also provided.

[0004] U.S. Patent No. 11,141,694 describes a system and process for capturing CO2 from flue gases. The systems can include a plurality of rotating absorber beds. In some aspects, a rotating absorber bed can be used as a water wash stage. For determining the size of the rotating beds, a method is provided for experimentally determining the number of equivalent transfer units and the area of the equivalent transfer units relative to a conventional packed bed configuration.

[0005] Indian Patent Application 201921008821 describes selecting packing material for a rotating packed bed so that the porosity varies from the interior to the exterior of the packed bed. The packing material porosity is selected so that the superficial gas velocities and superficial liquid velocities within the packing material remain substantially constant as the liquids and gases flow radially through the bed.

[0006] Chinese Patent Publication CN 103521160 describes a multi-stage rotating packed bed system.SUMMARY OF THE INVENTION

[0007] In some aspects, an integrated rotating packed bed adsorber is provided. The adsorber includes an adsorber housing comprising: a first compartment having an associated first liquid inlet and first liquid outlet, a second compartment having an associated second liquid inlet and second liquid outlet, a third compartment having an associated third liquid inlet and third liquid outlet, a housing gas inlet associated with the third compartment, and a housing gas outlet associated with the first compartment. The adsorber further includes a first packed bed within the first compartment rotatably mounted on a first rotor, the first packed bed comprising a first packing material having a first average surface area perunit volume. The adsorber further includes a second packed bed within the second compartment rotatably mounted on a second rotor, the second packed bed comprising a second packing material having a second average surface area per unit volume that is different from the first average surface area per unit volume. Additionally, the adsorber includes a third packed bed within the third compartment rotatably mounted on a third rotor, the third packed bed comprising a third packing material having a third average surface area per unit volume different from the second average surface area per unit volume. In various aspects, the first compartment can include a first gas inlet, the second compartment can include a second gas outlet in fluid communication with the first gas inlet, and a second gas inlet, and the third compartment can include a third gas outlet in fluid communication with the second gas inlet.

[0008] In some aspects, a method of removing CO2 from a flue gas is provided. The method includes introducing a flue gas at a first temperature into an outer region of a first compartment, the first compartment comprising a first rotating packed bed comprising a first packing material having a first average surface area per unit volume. The method further includes introducing a cooling fluid having a cooling fluid viscosity into a central region of the first compartment. The method further includes contacting the cooling fluid with the flue gas while rotating the first rotating packed bed to produce a cooled flue gas and a heated cooling fluid. The method further includes contacting the cooled flue gas with an amine solution in a second compartment in the presence of a second rotating packed bed while rotating the second rotating packed bed to form a CC -depleted gas and a CCh-rich amine solution, the second rotating packed bed comprising a second packing material having a second average surface area per unit volume that is different from the first average surface area per unit volume, the amine solution having a solution viscosity that is higher than the cooling fluid viscosity. The method further includes contacting the CO2- depleted gas with a wash solution in a third compartment in the presence of a third rotating packedbed while rotating the third rotating packed bed to form a washed exhaust gas, the third rotating packed bed comprising a third packing material having a third average surface area per unit volume different from the second average surface area per unit volume.BRIEF DESCRIPTION OF THE DRAWING

[0009] FIG. 1 shows an example of an integrated rotating packed bed configuration.

[0010] FIG. 2 shows carbon capture level versus liquid to gas ratio at various CO2 concentration for the input gas flow to a rotating packed bed capture stage.

[0011] FIG. 3 shows carbon capture level versus liquid to gas ratio at amine concentrations for a rotating packed bed capture stage.

[0012] FIG. 4 shows carbon capture level versus CO2 content of the aqueous amine prior to the start of adsorption.

[0013] FIG. 5 shows carbon capture level versus rotating speed for various amine concentrations for a rotating packed bed capture stage.

[0014] FIG. 6 shows carbon capture level versus gas flow rate for a rotating packed bed capture stage.

[0015] FIG. 7 shows carbon capture level versus liquid flow rate for a rotating packed bed capture stage.

[0016] FIG. 8 shows modeled results for cooling stages of an integrated rotating packed bed configuration.

[0017] FIG. 9 shows modeled results for capture stages of an integrated rotating packed bed configuration.

[0018] FIG. 10 shows modeled results for wash stages of an integrated rotating packed bed configuration.

[0019] FIG. 11 shows inlet and outlet gas temperatures for the cooling stage of integrated rotating packed bed configurations having packing materials with various surface areas per unit volume.

[0020] FIG. 12 shows amounts of CO2 captured for integrated rotating packed bed configurations having various packed bed outer radial distances and having packing materials with various surface areas per unit volume.

[0021] FIG. 13 shows a comparison of volume requirements for performing similar amounts of cooling in a conventional packed bed versus a rotating packed bed.

[0022] FIG. 14 shows a comparison of liquid flow rate requirements for performing similar amounts of cooling in a conventional packed bed versus a rotating packed bed.

[0023] FIG. 15 shows a comparison of pressure drop in a cooling stage for performing similar amounts of cooling in a conventional packed bed versus a rotating packed bed.DETAILED DESCRIPTION OF THE INVENTION

[0024] All numerical values within the detailed description and the claims herein are modified by “about” or “approximately” the indicated value, and take into account experimental error and variations that would be expected by a person having ordinary skill in the art.Overview

[0025] In various aspects, systems and methods are provided for performing amine capture on a heated flue gas using multiple rotating packed beds. By integrating a series of rotating packed beds to perform cooling of the flue gas, removal of CO2 from the flue gas by contact with an aqueous amine, and washing of the gaseous effluent from CO2 removal step to remove any entrained amine, the equipment footprint and overall equipment volume required for CO2 capture can be significantly reduced. The integration of cooling, CO2 removal, and washing can be integrated into a series of packed beds in part by using different packing materials in the various packed beds. The use of different packing materials can allow the cooling, CO2 removal, and wash steps to be performed with high effectiveness in each bed in spite of the substantial differences in viscosity between the liquids being contacted with the packed beds.

[0026] In conventional systems for capture of CO2 from streams such as flue gas streams, the typical amine capture system includes a series of three towers containing packed beds as part of the configuration. The first tower in the configuration corresponds to a cooling tower to reduce the temperature of the incoming flue gas to a target level. The second tower corresponds to the capture stage, where the cooled flue gas is contacted with an aqueous amine to form a CCh-enriched amine stream and a CO2-depleted flue gas. The CO2 depleted flue gas is then passed through a water wash tower to remove any amine entrained in the gas. The packing material in the towers provides additional surface area for contact between the liquid phase in each stage (cooling liquid, aqueous amine, wash) and the gas phase. During operation, the liquid flows are introduced into the towers at a location above the gas entry point. The liquids falls in the tower based on gravity, so that the gas flow and the liquid flow corresponds to counter-current contact. The packing material insidethe towers provides a large surface area for the liquid(s) to spread out on, with the hope of increasing the contact between the gases and the liquids.

[0027] While the above configuration is effective, one of the difficulties is that the packed bed towers have a substantial vertical footprint. This can limit the ability to incorporate aqueous amine capture systems into locations with limited footprint.

[0028] In various aspects, the above difficulties with excessive equipment footprint can be overcome by using a series of rotating packed beds to perform the cooling, CO2 capture, and wash steps during removal of CO2 from a CC -containing stream, such as a flue gas stream. In such aspects, the packing material of the packed beds can differ in each stage. By varying the packing material, efficient cooling, CO2 capture, and / or washing can be achieved in each packed bed even though the viscosity of the liquid phase in the packed beds may vary substantially.

[0029] In addition to varying the packing material in the packed beds, it has been discovered that the gaps between the packing material and other surfaces within the volumes containing the packed beds can have an impact on the efficiency of the packed bed stages.

[0030] Still another benefit of using integrated rotating packed beds for amine capture of CO2 is that different types of amines can be used. Due to the higher velocities created by the spinning of a rotating packed bed (relative to the velocities in a gravity-drained packed bed tower), thinner layers of liquid film and / or smaller liquid droplets can be formed in a rotating packed bed. This can switch the nature of the absorption from an equilibrium-driven adsorption mode to a kinetically-driven adsorption mode. This can enable improved CO2 sorption due to use of alternative amines that have lower efficiency in an equilibrium-driven sorption environment but that have faster sorption I desorption kinetics in a kinetic ally-drive sorption environment.DEFINITIONS

[0031] In this discussion, the volume of a packed bed is defined relative to the axis of rotation for the packed bed. The volume of a packed bed corresponds to an annular volume, with the center of the annulus corresponding to the axis of rotation for the packed bed. The outer radius of the annulus is defined as the minimum radius that forms a circle that contains the entire amount of packing material for the packed bed. The inner radius of the annulus is defined as the maximum radius that forms a circle that does not contain any of the packing material. The height of the annulus is defined by two planes that are perpendicular to the axis of rotation. The heightcorresponds to the minimum distance between two such planes that have the entire amount of packing material for the packed bed between the planes.

[0032] It is noted that rotating packed beds will typically have a roughly annular shape, with a central axis that roughly coincides with the axis of rotation of the packed bed. In various aspects, the one or more liquid inlets may be located closer to the axis of rotation than the packed bed. In such aspects, a radial inlet distance is defined as the distance from the axis of rotation to where a liquid inlet introduces liquid into the volume containing the packed bed. The radial inlet distance will typically be greater than zero due to the fact that some type of tube or column carrying the liquid will be roughly concentric with the axis of rotation. In some aspects, the radial inlet distance can correspond to the radius of such a tube or column that is roughly concentric with the axis of rotation.Packing Material and Liquid Viscosities

[0033] Conventionally, the type and amount of amine used during an aqueous amine process for CO2 capture is constrained by the nature of the contacting tower. Because liquid movement in the tower is based on gravity, the droplets and / or films of liquid formed on the packing material in a tower are relatively large in size (droplets) and / or thickness (films), so that most of the sorption of CO2 occurs after substantial diffusion of the CO2 into the droplet or film. As a result, the sorption of CO2 by the amine is primarily driven by considerations related to equilibrium considerations and / or bulk transport or diffusion within the droplets or film. Additionally, the concentration of the amine in the aqueous solution is limited, so that the size of the droplets and / or thickness films formed on the packing material are not further increased, which would result in still lower efficiency. Based on these considerations, the amines used for aqueous amine capture are typically amines with beneficial properties for sorption and desorption under equilibrium conditions in dilute solution. Examples of such amines include, but are not limited to, amines such as monoethanolamine (MEA), methyldiethanolamine (MDEA), 2-amino-2-methylpropanol (AMP), and diethanolamine (DEA). Such amines are used in aqueous solution at relatively low concentrations of 10 wt% or less for DEA (higher viscosity amine) or 30 wt% or less for MEA (lower viscosity amine).

[0034] By using a rotating packed bed for contacting a C Ch-containing gas with aqueous amine, the use of different types and / or amounts of amine can be enabled. Due to the higher acceleration forces present in a rotating packed bed, the droplet size and / or film thickness on the packing material is substantially less than would be present in a conventional tower. Such thinner films and / or smaller droplet sizes can be present even when substantially higher viscosity solutionsare used. Due to the smaller transport distances, a much higher percentage of the amine can be at or near the surface of a droplet or liquid, so that thin film kinetic factors can become predominant. This allows for the use of different amines that have improved operation for kinetically-driven sorption. Examples of such amines are aromatic amines such as piperazine. Additionally or alternately, when using either a conventional amine or a amine with improved operation for kinetically-driven sorption, a higher concentration of amine can be used in the aqueous amine solution. In some aspects, the amine concentration can be 20 wt% to 80 wt%, or 40 wt% to 80 wt%, or 20 wt% to 60 wt%, or 40 wt% to 60 wt%.

[0035] In various aspects, the use of rotating packed beds for removing CO2 from a CO2- containing gas flow can be facilitated and / or improved by using different packing materials for different beds. In particular, the packing materials can be varied to account for differences in viscosity between the liquids exposed to different rotating packed beds.

[0036] The packing material for a rotating bed can correspond to any convenient type of structure that provides a target amount of surface area per volume. One option is to use layers of a mesh, such as a wire mesh, so that surface area is provided by the surface of the wires while the openings in the mesh allow for transport of fluids. Such a mesh can be provided in any convenient format. One option can be sheets of mesh that traverse at least a portion of an arc or circle at a radius within the packed bed. Another option can be to have a plurality of mesh cylinders arranged within the packed bed. The shape of the wire (or other material) forming the mesh can be any convenient shape that provides a target surface area per volume within the packed bed.

[0037] One option for characterizing the packing material is based on the surface area of the packing material per unit volume within a packed bed. The surface area per unit volume is defined as the total surface area of the packing material in a packed bed divided by the volume of the packed bed.

[0038] Another option is to characterize the surface area of the packing material within the smallest annular volume that contains 95% of the packing material surface area. By defining the average surface area within the smallest annular volume containing 95% of the packing material surface area, a representative average surface area value can be determined while avoiding any difficulties due to the fact that small amounts of packing material might be located away from the main portion of the packing material.

[0039] Still another option for characterizing the surface area of the packing material is to characterize the surface area within a smaller annular volume. In some aspects, the surface area of the packing material can be varied within the packed bed. For example, the packing material canbe arranged so that the surface area per unit volume increases with the radial distance from the center of the packed bed. This provides additional surface area toward the edges of the packed bed, which can help with maintaining thin films and / or droplets of liquid toward the edge of a packed bed where the centrifugal forces will be greater. In such aspects, the surface area per unit volume in different annular volumes within packed bed can be separately characterized. In some aspects, the surface area per unit volume can be characterized in a portion of the packed bed, such as an annular volume corresponding to 50% of the total volume of the packed bed, or an annular volume corresponding to 33% of the total volume of the packed bed, or another convenient annular volume within the packed bed.

[0040] The surface area per unit volume for the packing material in a packed bed (or within an annular volume in the packed bed) can generally vary from 300 m2 / m3to 10000 m2 / m3. It is noted that still higher surface area per unit volume values could be used, but it is believed that little or no additional benefit is provided by further increases in the surface area per unit volume.

[0041] In various aspects, the packing material in a bed with a lower viscosity fluid (such as a packed bed for cooling gas flow or a packed bed for a wash flow) can have a higher surface area per unit volume than the packing material in a bed with a higher viscosity fluid (such as a packed bed for CO2 capture where a gas flow is exposed to an high concentration aqueous amine). For clarity, the optimum surface area / volume with a high viscous liquid gets reduced due to the reduction of velocity to maintain the same pressure drop. Liquid holdup is directly proportional to the viscosity and the surface area availability is inversely proportional to the viscosity. Surface area is high due to the formation of thin droplets.

[0042] In some aspects, the surface area per unit volume for the packing material in a cooling stage can be 1500 m2 / m3to 10000 m2 / m3, or 2000 m2 / m3to 10000 m2 / m3, or 3000 m2 / m3to 10000 m2 / m3, or 5000 m2 / m3to 10000 m2 / m3, or 1500 m2 / m3to 6500 m2 / m3, or 2000 m2 / m3to 6500 m2 / m3, or 3000 m2 / m3to 6500 m2 / m3, or 1500 m2 / m3to 5000 m2 / m3, or 2000 m2 / m3to 5000 m2 / m3, or 2500 m2 / m3to 5000 m2 / m3. Additionally or alternately, the surface area per unit volume for the packing material in a capture stage can be 500 m2 / m3to 4000 m2 / m3, or 1500 m2 / m3to 4000 m2 / m3, or 2000 m2 / m3to 4000 m2 / m3, or 2500 m2 / m3to 4000 m2 / m3. Still further additionally or alternately, the surface area per unit volume for the packing material in a CO2 capture stage can be lower than the surface area per unit volume for the packing material in at least one of a cooling stage and a wash stage by 500 m2 / m3or more, or 1000 m2 / m3or more, or 1500 m2 / m3or more, such as up to 3000 m2 / m3or possibly still more.

[0043] Various sizes of rotating packed beds can be used, depending in part on the available footprint. In various aspects, the annular volume containing the packing material can have an outer radius (as defined herein) of 0.5 meters to 4.0 meters, or 1.0 meters to 4.0 meters, or 1.5 meters to 4.0 meters, or 2.5 meters to 4.0 meters, or 0.5 meters to 3.0 meters, or 1.0 meters to 3.0 meters, or 1.5 meters to 3.0 meters. Additionally or alternately, the annular volume containing the packing material can have an inner radius (as defined herein) of 0.3 meters to 1.5 meters, or 0.3 meters to 1.0 meters, or 0.5 meters to 1.5 meters, or 0.5 meters to 1.0 meters. Further additionally or alternately, the annular volume containing the packing material can have a height (as defined herein) of 0. 1 meters to 0.5 meters, or 0.2 meters to 0.5 meters. In various aspects, the outer radius can be greater than the inner radius by 0.5 meters or more, or 1.0 meters or more, such as up to 2.5 meters or possibly still more.

[0044] The difference between the inner radius of the packed bed (i.e., the inner radius for the smallest annular volume containing the packing material) and the radial inlet distance for a liquid inlet defines a gap between the packed bed and the liquid inlet. In various aspects, this distance can be 40 mm to 100 mm, or 40 mm to 70 mm. In some aspects, this difference can instead be calculated using the difference between the inner radius of the smallest annular volume containing 95% of the surface area of the packing material and the radial inlet distance for a liquid inlet.

[0045] A gap can also exist between the outer radius of the packed bed and the outer wall of the volume containing the packed bed. In various aspects, this distance can be 40 mm to 150 mm, or 40 mm to 100 mm. The outer radius used for determining this difference can be the outer radius of the smallest annular volume containing all of the packing material in the compartment, or the outer radius of the smallest annular volume containing 95% of the surface area of the packing material.

[0046] In various aspects, the viscosity of the liquid introduced into the packed bed stages can also vary. For the cooling stage, the liquid exposed to the packed bed can have a dynamic viscosity at 20°C of 0.8 mPa-s to 1.5 mPa-s, or 0.8 mPa-s to 1.2 mPa-s, or 1.0 mPa-s to 1.5 mPa-s. It is noted that low concentration aqueous solutions can have a dynamic viscosity at 20°C of roughly 1.0 mPa-s.

[0047] For the capture stage, aqueous amine solutions can have increasing viscosity as the concentration of amine is increased. For relatively low concentration aqueous amine solutions, such as amine solutions with an amine concentration of 10 wt% or less, the dynamic viscosity at 20°C can be 0.8 mPa-s to 1.5 mPa-s. In other aspects, an aqueous amine solution used in the capture stage can have a higher amine concentration, such as 10 wt% or more, or 20 wt% or more,or 40 wt% or more, such as up to 80 wt% or possibly still higher. In such aspects, the dynamic viscosity at 20°C of the aqueous amine can be 20 mPa-s to 200 mPa-s, or 20 mPa-s to 150 mPa-s, or 20 mPa-s to 80 mPa-s, or 50 mPa-s to 200 mPa-s, or 50 mPa-s to 150 mPa-s, or 50 mPa-s to 120 mPa-s.

[0048] For the wash stage, the input flow to the wash stage can have a similar dynamic viscosity to the input flow for the cooling stage. Thus, at the input to the wash stage, the liquid flow can have a dynamic viscosity at 20°C of 0.8 mPa-s to 1.5 mPa-s, or 0.8 mPa-s to 1.2 mPa-s, or 1.0 mPa-s to 1.5 mPa-s. Because some entrained amine is present within the gas flow entering the wash stage, as the entrained amine is transferred from the gas flow to the wash liquid, the dynamic viscosity of the wash liquid can increase. Depending on the amount of entrained amine that is transferred into the wash liquid, the dynamic viscosity of the wash liquid can vary as it passes through the wash stage. In some aspects, the dynamic viscosity of the wash liquid can increase between the input to the wash stage and the exit from the wash stage by 0.5 mPa-s to 4.0 mPa-s, or 0.5 mPa-s to 3.0 mPa-s, or 0.5 mPa-s to 2.0 mPa-s, or 1.0 mPa-s to 4.0 mP-as, or 1.0

[0049] In various aspects, the footprint of an aqueous amine CO2 capture system can be reduced or minimized by using an integrated series of packed beds to provide the interface for contacting a CCh-containing gas flow with a cooling liquid, an aqueous amine, and a wash liquid.

[0050] The integrated series of packed beds can include one or more packed beds for cooling of a gas flow, one or more packed beds for contacting the resulting cooled gas flow with an aqueous amine, and one or more packed beds for contacting the resulting CCh-depleted gas flow with a wash liquid to remove entrained amine. In this description, the different stages may be described as containing only one packed bed each for convenience. However, it is understood that multiple packed beds could be used in series and / or in parallel within a stage (i.e., cooling stage, capture stage, wash stage).

[0051] During operation, a CCh-containing gas flow is introduced into a first stage (corresponding to a cooling stage) that includes at least one packed bed. The packed bed rotates about an axis. The CCh-containing gas is introduced via one or more inlets in a perimeter portion of the compartment containing the packed bed. This perimeter volume is constructed so that substantially all of the CCh-containing gas is forced to pass through the packing material to move from the inlet(s) of the compartment to the exit(s) from the compartment. The CCh-containing gas enters the packing material at or near the outer perimeter of the annular volume that contains allof the packing material, or optionally at or near the outer perimeter of the annular volume that contains 95% of the packing material. It is noted that entering at or near the outer perimeter of an annular volume includes the option of having the COi-containing gas enter the packing material through a bottom surface and / or top surface of the annular volume, so long as the entry is near the outer perimeter.

[0052] The gas can then travel through the bed during operation to come into contact with a cooling liquid. The cooling liquid is introduced into the packing material from near the center of the packed bed, so the contact with the cooling liquid is substantially counter-curent. After passing through the packed bed, the cooled gas can exit from the compartment containing the packed bed via at least one gas outlet near the center of the compartment. Fluid communication between the packed bed and the at least one gas outlet is provided by one or more openings located in proximity to the central axis of the packed bed. Thus, in order to exit from the packed bed, the gas travels from the exterior of the packed bed toward the center of the packed bed. In some aspects, the at least one gas outlet can be located on a surface of the compartment that is near or adjacent to the compartment for an adsorption stage. The cooled gas is then passed to the next stage.

[0053] The cooling liquid (such as water) is introduced into the packed bed via one or more liquid inlets. The one or more liquid inlets can be arranged in proximity to the central axis, so that the one or more liquid inlets are closer to the central axis than the inner edge of the packed bed and / or the inner perimeter of the annulus containing 100% of the packing material. The liquid then travels radially through the packed bed, accelerated by the rotation of the bed. After contact with the gas, the warmed liquid exits from the volume containing the packed bed through one or more liquid outlets located between the outer radius of the packed bed and the wall of the volume containing the packed bed. Optionally, the warmed liquid can be cooled and then recycled for use as cooling liquid.

[0054] The cooling stage can be used to reduce the temperature of the cooled gas flow to a temperature that is more favorable for adsorption of CO2. For example, one type of COi-containing gas is a flue gas from a combustion source. Flue gases are often at elevated temperature as a byproduct of the combustion reaction used to form the flue gas. In some aspects, prior to cooling, the CO2-containing gas can be at a temperature of 60°C to 400°C, or 60°C to 300°C, or 60°C to 200°C, or 80°C to 200°C, or 80°C to 150°C. The cooling stage can be used to reduce the temperature such a hot CO2-containing gas to a temperature between 20°C and 70°C, or 20°C to 60°C. Additionally or alternately, the difference in temperature between the CCh-containing gas and the cooled CO2-containing gas can be 20°C or more, or 40°C or more, or 60°C or more, or 80°C or more, or 100°C or more, such as up to 160°C or possibly still more.

[0055] The cooled CCh-containing gas is then introduced into a second stage (corresponding to a CO2 capture stage) that includes at least a second packed bed. The second packed bed rotates about an axis. The axis can be the same or substantially similar to the axis of rotation for the packed bed in the first stage. Optionally, the rotor or other mechanism for rotating the second packed bed can be the same as the rotational mechanism for the first packed bed. Optionally, the second packed bed can rotate at substantially the same speed as the first packed bed.

[0056] The cooled COz-containing gas is introduced via one or more inlets in a perimeter portion of the compartment containing the second packed bed. This perimeter volume is constructed so that substantially all of the cooled COz-containing gas is forced to pass through the packing material to move from the inlet(s) of the compartment to the exit(s) from the compartment. The cooled COi-containing gas enters the packing material at or near the outer perimeter of the annular volume that contains all of the packing material, or optionally at or near the outer perimeter of the annular volume that contains 95% of the packing material. It is noted that entering at or near the outer perimeter of an annular volume includes the option of having the cooled C Ch-containing gas enter the packing material through a bottom surface and / or top surface of the annular volume, so long as the entry is near the outer perimeter.

[0057] The gas can then travel through the bed during operation to come into contact with an aqueous amine liquid. The aqueous amine liquid is introduced into the packing material from near the center of the packed bed, so the contact with the aqueous amine liquid is substantially counter- curent. After passing through the packed bed, the CCh-depleted gas can exit from the compartment containing the packed bed via at least one gas outlet near the center of the compartment. Fluid communication between the packed bed and the at least one gas outlet is provided by one or more openings located in proximity to the central axis of the packed bed. Thus, in order to exit from the packed bed, the gas travels from the exterior of the packed bed toward the center of the packed bed. In some aspects, the at least one gas outlet can be located on a surface of the compartment that is near or adjacent to the compartment for a wash stage. The COz-depleted gas is then passed to the next stage.

[0058] The aqueous amine liquid (such as water) is introduced into the packed bed via one or more liquid inlets. The one or more liquid inlets can be arranged in proximity to the central axis, so that the one or more liquid inlets are closer to the central axis than the inner edge of the packed bed and / or the inner perimeter of the annulus containing 100% of the packing material. The liquidthen travels radially through the packed bed, accelerated by the rotation of the bed. After contact with the gas, the CC -rich liquid exits from the volume containing the packed bed through one or more liquid outlets located between the outer radius of the packed bed and the wall of the volume containing the packed bed. Optionally, COi-rich liquid can be passed into a separate stage for regeneration of the amine via desorption of the CO2. The desorbed CO2 can then be used for any convenient purpose, such as sequestration, use an industrial or commercial process, or another use.

[0059] The capture stage can be used to reduce the CO2 concentration of the CO2-containing gas to a target level. The amount of CO2 reduction can be characterized in various ways. In some aspects, the CO2 content of the cooled C Ch-containing gas can be 2.0 vol% to 20 vol%, or 2.0 vol% to 15 vol%, or 2.0 vol% to 10 vol%, or 2.0 vol% to 6.0 vol%, or 3.0 vol% to 20 vol%, or 3.0 vol% to 15 vol%, or 3.0 vol% to 10 vol%, or 5.0 vol% to 20 vol%, or 5.0 vol% to 15 vol%, or 5.0 vol% to 10 vol%. After exposure to the aqueous amine, the CCh-depleted gas can have a CO2 concentration of 3.0 vol% or less, or 2.0 vol% or less, or 1.0 vol% or less, or 0.5 vol% or less, such as down to having substantially no CO2 content (0.05 vol% or less). Additionally or alternately, the CO2 content of the CCh-depleted gas can be 20% or less of the CCh-content of the cooled CO2- containing gas (relative to the CO2 content of the cooled CCh-containing gas), or 15% or less, or 10% or less, such as down to 1.0% or possibly still less. It is noted that reducing the CO2 content to 20% or less of the original content can equivalently be expressed as capture of 80% or more of the CO2 from the stream. Similarly, reducing the CO2 content of a gas stream to 10% or less of the original content can equivalently be expressed as capturing 90% or more of the CO2 from a gas stream. It is further noted that the cooling stage can result in some CO2 removal during formation of the cooled CCh-containing gas, such as removal of 5.0% to 30% of the CO2 present in the initial flue gas or other C Ch-containing gas. For example, if the CCh-containing gas prior to cooling contains roughly 4.0 vol% CO2, the cooled CCh-conlaining gas can contain could contain between 2.8 vol% to 3.8 vol% of CO2. This CO2 removal during cooling is believed to be due to sorption of CO2 by the water or other cooling liquid used in the cooling stage.

[0060] The CCh-depleted gas is then introduced into a third stage (corresponding to a wash stage) that includes at least a third packed bed. The third packed bed rotates about an axis. The axis can be the same or substantially similar to the axis of rotation for the packed bed in the first stage and / or the packed bed in the second stage. Optionally, the rotor or other mechanism for rotating the third packed bed can be the same as the rotational mechanism for the first packed bed and / or the second packed bed. Optionally, the third packed bed can rotate at substantially the same speed as the first packed bed and / or the second packed bed.

[0061] The C Ch-depleted gas is introduced via one or more inlets in a perimeter portion of the compartment containing the packed bed. This perimeter volume is constructed so that substantially all of the CCh-depleted gas is forced to pass through the packing material to move from the inlet(s) of the compartment to the exit(s) from the compartment. The CCh-depleted gas enters the packing material at or near the outer perimeter of the annular volume that contains all of the packing material, or optionally at or near the outer perimeter of the annular volume that contains 95% of the packing material. It is noted that entering at or near the outer perimeter of an annular volume includes the option of having the C Ch-depleted gas enter the packing material through a bottom surface and / or top surface of the annular volume, so long as the entry is near the outer perimeter.

[0062] The CCh-depleted gas can then travel through the bed during operation to come into contact with a wash liquid. The wash liquid is introduced into the packing material from near the center of the packed bed, so the contact with the wash liquid is substantially counter-curent. After passing through the packed bed, the washed CC -depleted gas can exit from the compartment containing the packed bed via at least one gas outlet near the center of the compartment. Fluid communication between the packed bed and the at least one gas outlet is provided by one or more openings located in proximity to the central axis of the packed bed. Thus, in order to exit from the packed bed, the gas travels from the exterior of the packed bed toward the center of the packed bed. The washed, CC -depleted gas can then be used for any convenient purpose. It is noted that the washed gas will typically be composed of nitrogen and water vapor.

[0063] The wash liquid (such as water) is introduced into the packed bed via one or more liquid inlets. The one or more liquid inlets can be arranged in proximity to the central axis, so that the one or more liquid inlets are closer to the central axis than the inner edge of the packed bed and / or the inner perimeter of the annulus containing 100% of the packing material. The liquid then travels radially through the packed bed, accelerated by the rotation of the bed. After contact with the gas, the wash liquid, which now contains amine that was transferred from the CCh-depleted gas, exits from the volume containing the packed bed through one or more liquid outlets located between the outer radius of the packed bed and the wall of the volume containing the packed bed. Optionally, the warmed liquid can be cooled and then recycled for use as cooling liquid. Optionally, at least a portion of the amine in the wash liquid can be recovered, which would optionally allow for recycle of the wash liquid. It is noted that after amine recovery, the recycled wash liquid can still have some amine content. In other words, full regeneration of the wash liquid is not required prior to recycle for use as wash liquid in a subsequent cycle.

[0064] FIG. 1 shows an example of an integrated configuration for using rotating packed beds for aqueous amine capture of CO2. Generally, the gas flows from the volume containing the cooling packed bed to the volume containing the capture packed bed to the volume containing the wash packed bed. By contrast, the liquid flows within a configuration enter and exit a single volume (and / or group of volumes performing the same function) without being passed directly to a volume containing another packed bed performing a different function.

[0065] In the example configuration shown in FIG. 1, one packed bed is shown in each stage, although it is understood that multiple beds could be included in a stage. In the example configuration shown in FIG. 1, the integrated system includes a cooling bed 115, a CO2 capture bed 145, and a wash bed 175. Cooling bed 115 is located within cooling volume 110. CO2 capture bed 145 is located within capture volume 140. Wash bed 175 is located within wash volume 170.

[0066] In the configuration shown in FIG. 1, the liquid flow 121 for cooling volume 110 is passed into volume 110 via one or more cooling inlets (not shown) that provide fluid communication with a cooling fluid source. The one or more cooling inlets can be in proximity to the axis of rotation for cooling bed 115. In this discussion, being in proximity to the axis of rotation means that the one or more cooling inlets are located closer to the central axis than an inner edge of the packing material of cooling bed 115. Liquid introduced into cooling volume 110 is accelerated by the rotation of the packed bed and travels radially to the outer perimeter of volume 110. The liquid can then exit 128 from volume 110 via one or more peripheral outlets.

[0067] The gas flow 131 for cooling volume 110 is passed into volume 110 via one or more gas inlets (not shown) so that the gas flow 131 is substantially introduced at or near the outer perimeter of cooling bed 115. In the configuration shown in FIG. 1, gas flow 131 is shown as being introduced into cooling volume 110 through a bottom surface of cooling volume 110. In other aspects, The gas flow 131 can be introduced into cooling volume 110 through a bottom surface, side surface, and / or top surface, so long as the gas flow 131 enters the packing material at or near an outer perimeter of the packing material. During operation, gas flow 131 passes through the packing material of cooling bed 115 toward the center of the compartment. The gas can then exit from volume 110 via one or more gas outlets. The exiting gas corresponds to cooled gas flow 161.

[0068] In the configuration shown in FIG. 1, the liquid flow 151 for capture volume 140 is passed into volume 140 via one or more central inlets that provide fluid communication with an aqueous amine source. The one or more central inlets can be in proximity to the axis of rotation for CO2 capture bed 145. In this discussion, being in proximity to the axis of rotation means that the one or more central inlets are located closer to the central axis than an inner edge of the packingmaterial of CO2 capture bed 145. Liquid introduced into capture volume 140 is accelerated by the rotation of the packed bed and travels radially to the outer perimeter of volume 140. The liquid can then exit 158 from volume 140 via one or more peripheral outlets.

[0069] The gas flow 161 for capture volume 140 is passed into volume 140 via one or more gas inlets so that the gas flow 161 is substantially introduced at or near the outer perimeter of capture bed 145. During operation, gas flow 161 passes through the packing material of capture bed 145 toward the center of the compartment. The gas can then exit from volume 140 via one or more gas outlets. The exiting gas corresponds to CCh-depleted gas flow 191.

[0070] In the configuration shown in FIG. 1, the liquid flow 181 for wash volume 170 is passed into volume 170 via one or more wash inlets that provide fluid communication with a wash fluid source. The one or more wash inlets can be in proximity to the axis of rotation for wash bed 175. In this discussion, being in proximity to the axis of rotation means that the one or more wash inlets are located closer to the central axis than an inner edge of the packing material of wash bed 175. Liquid introduced into wash volume 170 is accelerated by the rotation of the packed bed and travels radially to the outer perimeter of volume 170. The liquid can then exit 188 from volume 170 via one or more peripheral outlets.

[0071] The gas flow 191 for wash volume 170 is passed into volume 170 via one or more gas inlets so that the gas flow 191 is substantially introduced at or near the outer perimeter of wash bed 175. During operation, gas flow 191 passes through the packing material of wash bed 175 toward the center of the compartment. The gas can then exit from wash volume 170 via one or more gas outlets. The exiting gas corresponds to washed gas flow 199.

[0072] It is noted that in alternative configurations, the rotating beds can be arranged in any convenient manner. For example, the rotating beds can be arranged in a configuration where the beds do not share a common axis of rotation. An example of such a configuration is to have an arrangement where the compartments containing the various stages are stacked on top of one another, but the rotating beds are oriented vertically, so that the axis of rotation is roughly perpendicular to the direction of gravitational pull. More generally, any other convenient configuration can be used, as it is not required for the compartments containing the different stages to have a specific spatial relationship.Examples

[0073] In order to further illustrate the benefits of using integrated rotating packed beds, both experimental runs and modeling runs were performed using various configurations.

[0074] FIGS. 2 - 7 shows results from a series of experimental runs that were performed using rotating packed beds that had packing materials with two different surface areas per volume. The results demonstrate how rotating packed bed performance can change based on changes in the surface area per unit volume of the packed bed. FIGS. 2 - 4 correspond to results from packed beds with a surface area per unit volume of 2132 m2 / m3, while FIGS. 5 - 7 correspond to results from packed beds with a surface area per unit volume of 500 m2 / m3. The experimental runs correspond to the second or “capture” stage of an integrated packed bed system. Thus, the liquid introduced into the rotating packed bed stage was an aqueous amine, while the gas was a C Ch- containing gas. In FIGS. 2 - 7, “CCL” refers to the carbon capture level, or the percentage of CO2 removed from the gas stream, and “L / G” refers to the weight ratio of liquid to gas.

[0075] The results shown in FIGS. 2 - 7 were used to develop an empirical model for rotating packed bed performance. In each of FIGS. 2 - 7, the carbon capture percentage is shown relative to other factors, such as amine concentration, gas and / or liquid flow rate, and rotational speed for the rotating disk. A couple of features can be understood from the data shown in FIG. 2 - 7. First, as shown in FIGS. 4 and 5, changes in the rotational speed at greater than 200 rpm (revolutions per minute) had only a modest impact on the amount of carbon capture. As shown in FIGS. 6 and 7, liquid flow rate has only a modest impact on the amount of carbon capture, while increasing the gas flow rate tends to somewhat reduce the amount of CO2 removed from the gas. One variable that has a noticeable impact on the amount of CO2 captured is the amount of amine present in the aqueous amine.

[0076] Based on various experimental runs (including experimental runs for cooling and wash stages), an empirical model was developed. FIGS. 8 - 10 show data from simulations performed using the model to simulate an integrated packed bed system for cooling. FIG. 8 shows data related to the cooling stage of the modeled integrated system. FIG. 9 shows data for a CO2 capture stage. FIG. 10 shows data for the wash stage. For the modeling runs shown in FIGS. 8 - 10, the input CO2-containing gas flow is intended to represent a combustion flue gas. The CO2-containing gas has an initial temperature of 300°C (573 Kelvin) and a CO2 content of 4.0 vol%. The amine that was modeled to generate the results in FIGS. 8 - 10 was monoethanolamine (ME A).

[0077] In the model, the CCF-containing gas is first introduced into the cooling stage. FIG. 8 shows two types of modeled results for the cooling stage. Data lines 810 and 820 show the temperature profile for the CCh-coniaining gas relative to the radius of the packed bed. It is noted that the gas is introduced below the level of the packed bed near the perimeter of the bed. This assists with mixing the gas with the cooling liquid. The cooling liquid is introduced at atemperature of roughly 40°C. As shown by data lines 810 and 820, the temperature of the gas drops to match the temperature of the cooling liquid (roughly 40°C) at all radial distances, with the exception of a narrow range of radial distances near the outer edge of the packed bed (near where the gas is introduced into the cooling stage). Changing the liquid to gas ratio from 0.25 (line 810) to 0.1 (line 820) results in only a small change in the temperature profile. Line 830 shows how the CO2 concentration in the gas varies with the radial distance at the liquid to gas ratio of 0.25. Near the outer edge of the packed bed, the CO2 concentration is roughly the same as the concentration of the input gas flow, corresponding to 4.0 mol% (or equivalently 4.0 vol%). As the gas moves toward the center of the packed bed, the CO2 is somewhat reduced by contact with the water, so that by the time the cooled C Ch-containing gas exits from the packed bed, the CO2 concentration has been reduced to roughly 3.3 vol%.

[0078] FIG. 9 shows two types of results for the capture stage. Line 910 shows the temperature of the gas flow as it moves from the outer radius of the packed bed toward the central axis. As shown in FIG. 9, the gas temperature increases from roughly 40°C (exit temperature from the cooling stage) to roughly 60°C at the end of contact with the aqueous amine. The size of this temperature increase can vary depending on the concentration of the amine in the aqueous amine liquid. Line 930 shows the CO2 concentration of the gas flow as the gas moves from the outer radius of the packed bed toward the central axis. The contact with the aqueous amine reduces the CO2 concentration in the gas flow from roughly 3.3 vol% to roughly 0.3 vol% or less, corresponding to 90% or greater CO2 removal.

[0079] FIG. 10 shows results for amine concentration remaining in the gas phase in the wash stage at three different liquid to gas ratios in the wash stage. Line 1040 corresponds to a liquid to gas ratio of 0.01. Line 1050 corresponds to a liquid to gas ratio of 0.1. Line 1060 corresponds to a liquid to gas ratio of 0.5. As shown in FIG. 10, increasing the liquid to gas ratio reduced the amount of MEA remaining in the gas flow as the gas flow exits from packed bed (near the central axis). At a liquid to gas ratio of 0.01, the MEA concentration is reduced from roughly 370 vppm (volume parts per million) to roughly 160 vppm. Increasing the liquid to gas ratio to 0.1 allowed the MEA concentration to be reduced to roughly 100 vppm, while increasing the liquid to gas ratio to 0.5 allowed the MEA concentration to be reduced to roughly 25 vppm.

[0080] FIG. 11 shows how changing the surface area per unit volume within a rotating packed bed can impact the performance of a stage, such as a cooling stage. In FIG. 11, the cooling of a gas flow is shown at various input gas flow rates for an input gas flow containing 4.0 vol% CO2. Line 1110 corresponds to the temperature of the input gas flow prior to entering the rotating packedbed. Line 1120 shows the resulting temperature of the gas flow after exiting a packed bed that contains a packing material having a surface area per unit volume of 500 m2 / m3. Line 1130 shows the resulting temperature of the gas flow after exiting a packed bed that contains a packing material having a surface area per unit volume of 2132 m2 / m3. It is noted that the modeled rotating packed beds for generating lines 1120 and 1130 otherwise had identical dimensions, and the lines in FIG. 11 based on modeling the same gas flow rates for each type of rotating packed bed. As shown in FIG. 11 , the volume of both rotating packed beds was sufficient to achieve roughly the same level of cooling, regardless of the input gas flow volume. However, the packed bed having the surface area per unit volume of 500 m2 / m3was only able to reduce the temperature of the gas flow to roughly 100°C. This was substantially independent of the gas flow rate, indicating that the limiting factor in cooling of the gas flow was the available surface area in the packed bed. By contrast, at a surface are per unit volume of 2132 m2 / m3, the temperature of the gas flow was reduced to a target value of roughly 40°C.

[0081] FIG. 12 shows modeled data on how changing surface area per unit volume for the packing material impacts CO2 capture performance in a packed bed. In FIG. 12, unless otherwise noted, the input conditions and rotating packed bed dimensions were identical for comparisons between packing materials with different surface areas per unit volume. In FIG. 12, the total amount of CO2 captured is shown (in kilotons per year, or kta) versus the CO2 concentration in the input flow gas. It is noted that increasing the CO2 concentration was accompanied by decreasing the gas flow rate, so that the same volume flow rate of CO2 was passed through the packed bed independent of the concentration of CO2 in the gas flow.

[0082] In FIG. 12, line 1210 corresponds to the amount of CO2 capture by the amine (in the aqueous amine solution) for a packed bed having an outer diameter for the packing material of 3.0 meters and a surface area per unit volume for the packing material of 2132 m2 / m3. Line 1220 corresponds to the amount of CO2 capture by the amine (in the aqueous amine solution) for a packed bed having an outer diameter for the packing material of 3.0 meters and a surface area per unit volume for the packing material of 500 m2 / m3. As shown in FIG. 12, using a higher surface area packing material results in a substantial increase in the amount of CO2 that can be captured. Increasing the concentration of CO2 in the input gas flow, by comparison, results in a much more modest increase in the amount of CO2 that is captured.

[0083] FIGS. 13 to 15 show model comparisons of the performance of rotating packed beds with the packed beds present in conventional towers or columns for the cooling step of an integrated CO2 capture process. FIG. 13 shows a comparison of the volume of packed bed orrotating packed bed that is required to cool a gas from 176°C to 41°C. As shown in FIG. 13, the volume of packing material required to perform this cooling step in a rotating packed bed is roughly 2 orders of magnitude lower than the volume of a conventional packed bed in a tower configuration. This represents a substantial vertical footprint savings, which can potentially enable installation of an integrated rotating packed bed CO2 capture system in environments that have insufficient space for a conventional aqueous amine-based CO2 capture system.

[0084] FIG. 14 shows a model comparison of the cooling liquid flow rate needed in a rotating packed bed system versus a conventional packed bed in order to reduce the temperature of the input gas flow from 176°C to 41°C. As shown in FIG. 14, at low gas flow rates, similar liquid flow rates are used in both configurations. However, as the gas flow rate is increased, the rotating packed bed can achieve the target level of cooling at lower liquid flow rates, so that roughly half as much cooling liquid is needed at higher gas flow rates.

[0085] FIG. 15 shows a model comparison of the pressure drop during cooling from 176°C to 41 °C for a rotating packed bed and a conventional packed bed. As shown in FIG. 15, the pressure drop in a conventional packed bed (i.e., tower configuration) is roughly constant regardless of the input gas flow rate. By contrast, as the gas flow rate is increased for the rotating packed bed, the pressure drop across the cooling stage increases.Additional Embodiments

[0086] Embodiment 1. A integrated rotating packed bed adsorber, comprising: an adsorber housing comprising: a first compartment having an associated first liquid inlet and first liquid outlet, a second compartment having an associated second liquid inlet and second liquid outlet, a third compartment having an associated third liquid inlet and third liquid outlet, a housing gas inlet associated with the third compartment, and a housing gas outlet associated with the first compartment; a first packed bed within the first compartment rotatably mounted on a first rotor, the first packed bed comprising a first packing material having a first average surface area per unit volume; a second packed bed within the second compartment rotatably mounted on a second rotor, the second packed bed comprising a second packing material having a second average surface area per unit volume that is different from the first average surface area per unit volume; and a third packed bed within the third compartment rotatably mounted on a third rotor, the third packed bed comprising a third packing material having a third average surface area per unit volume different from the second average surface area per unit volume, wherein the first compartment comprises a first gas inlet, wherein the second compartment comprises a second gas outlet in fluidcommunication with the first gas inlet, and a second gas inlet, and wherein the third compartment comprises a third gas outlet in fluid communication with the second gas inlet.

[0087] Embodiment 2. The adsorber of Embodiment 1, wherein the first rotor is the same as the second rotor, or wherein the first rotor is the same as the third rotor, or a combination thereof.

[0088] Embodiment 3. A method of removing CO2 from a flue gas, comprising: introducing a flue gas at a first temperature into an outer region of a first compartment, the first compartment comprising a first rotating packed bed comprising a first packing material having a first average surface area per unit volume; introducing a cooling fluid having a cooling fluid viscosity into a central region of the first compartment; contacting the cooling fluid with the flue gas while rotating the first rotating packed bed to produce a cooled flue gas and a heated cooling fluid; contacting the cooled flue gas with an amine solution in a second compartment in the presence of a second rotating packed bed while rotating the second rotating packed bed to form a C Ch-de leted gas and a CCh-rich amine solution, the second rotating packed bed comprising a second packing material having a second average surface area per unit volume that is different from the first average surface area per unit volume, the amine solution having a solution viscosity that is higher than the cooling fluid viscosity; contacting the CC -depleted gas with a wash solution in a third compartment in the presence of a third rotating packed bed while rotating the third rotating packed bed to form a washed exhaust gas, the third rotating packed bed comprising a third packing material having a third average surface area per unit volume different from the second average surface area per unit volume.

[0089] Embodiment 4. The method of Embodiment 3, wherein the solution viscosity comprises a dynamic viscosity at 20°C of 20 mPa-s to 200 mPa-s.

[0090] Embodiment 5. The method of Embodiment 3 or 4, wherein the cooling fluid viscosity comprises a dynamic viscosity at 20°C of 0.8 mPa-s to 1.5 mPa-s, or wherein the wash solution has a wash solution viscosity comprising a dynamic viscosity at 20°C of 0.8 mPa-s to 1.5 mPa-s, or a combination thereof.

[0091] Embodiment 6. The method of any of claims 3 to 5, wherein the liquid to gas weight ratio is 0.1 or more.

[0092] Embodiment 7. The adsorber or method of any of the above embodiments, wherein the first average surface area per unit volume is defined as an average surface area per unit volume within a smallest annular volume containing 95% of the surface area of the packing material in the first compartment, wherein the second average surface area per unit volume is defined as an average surface area per unit volume within a smallest annular volume containing 95% of thesurface area of the packing material in the second compartment, and wherein the third average surface area per unit volume is defined as an average surface area per unit volume within a smallest annular volume containing 95% of the surface area of the packing material in the third compartment.

[0093] Embodiment 8. The adsorber or method of any of the above embodiments, wherein the first average surface area per unit volume is greater than the second average surface area per unit volume, or wherein the third average surface area per unit volume is greater than the second average surface area per unit volume, or a combination thereof.

[0094] Embodiment 9. The adsorber or method of any of the above embodiments, wherein the first average surface area per unit volume is greater than the second average surface area per unit volume by 500 m2 / m3or more, or wherein the third average surface area per unit volume is greater than the second average surface area per unit volume by 500 m2 / m3or more, or a combination thereof.

[0095] Embodiment 10. The adsorber or method of any of the above embodiments, wherein an outer gap between an outer radius of the second packed bed and a surface of the second compartment is 40 mm to 150 mm, the outer radius of the second packed bed being defined as the outer radius of the smallest annular volume containing 95% of the surface area of the packing material in the second compartment.

[0096] Embodiment 11. The adsorber or method of any of Embodiments 1 - 10, wherein an outer gap between an outer radius of the second packed bed and a surface of the second compartment is 40 mm to 150 mm, the outer radius of the second packed bed being defined as the outer radius of the smallest annular volume containing all of the packing material in the second compartment.

[0097] Embodiment 12. The adsorber or method of any of the above embodiments, wherein an inner gap between an inner radius of the second packed bed and a surface comprising the second liquid inlet is 40 mm to 100 mm, the inner radius of the second packed bed being defined as the inner radius of the smallest annular volume containing 95% of the surface area of the packing material in the second compartment.

[0098] Embodiment 13. The adsorber or method of any of Embodiments 1 - 12, wherein an inner gap between an inner radius of the second packed bed and a surface comprising the second liquid inlet is 40 mm to 100 mm, the inner radius of the second packed bed being defined as the inner radius of the smallest annular volume containing all of the packing material in the second compartment.

[0099] Certain features have been described using a set of numerical upper limits and a set of numerical lower limits. It should be appreciated that ranges from any lower limit to any upper limit are contemplated unless otherwise indicated. Certain lower limits, upper limits and ranges appear in one or more claims below. All numerical values take into account experimental error and variations that would be expected by a person having ordinary skill in the art.

[0100] The foregoing description of the disclosure illustrates and describes the present methodologies. Additionally, the disclosure shows and describes exemplary methods, but it is to be understood that various other combinations, modifications, and environments may be employed and the present methods are capable of changes or modifications within the scope of the concept as expressed herein, commensurate with the above teachings and / or the skill or knowledge of the relevant art.

Claims

CLAIMS1. A integrated rotating packed bed adsorber, comprising: an adsorber housing comprising: a first compartment having an associated first liquid inlet and first liquid outlet, a second compartment having an associated second liquid inlet and second liquid outlet, a third compartment having an associated third liquid inlet and third liquid outlet, a housing gas inlet associated with the third compartment, and a housing gas outlet associated with the first compartment; a first packed bed within the first compartment rotatably mounted on a first rotor, the first packed bed comprising a first packing material having a first average surface area per unit volume; a second packed bed within the second compartment rotatably mounted on a second rotor, the second packed bed comprising a second packing material having a second average surface area per unit volume that is different from the first average surface area per unit volume; and a third packed bed within the third compartment rotatably mounted on a third rotor, the third packed bed comprising a third packing material having a third average surface area per unit volume different from the second average surface area per unit volume, wherein the first compartment comprises a first gas inlet, wherein the second compartment comprises a second gas outlet in fluid communication with the first gas inlet, and a second gas inlet, and wherein the third compartment comprises a third gas outlet in fluid communication with the second gas inlet.

2. The adsorber of claim 1 , wherein the first rotor is the same as the second rotor, or wherein the first rotor is the same as the third rotor, or a combination thereof.

3. A method of removing CO2 from a flue gas, comprising: introducing a flue gas at a first temperature into an outer region of a first compartment, the first compartment comprising a first rotating packed bed comprising a first packing material having a first average surface area per unit volume; introducing a cooling fluid having a cooling fluid viscosity into a central region of the first compartment; contacting the cooling fluid with the flue gas while rotating the first rotating packed bed to produce a cooled flue gas and a heated cooling fluid; contacting the cooled flue gas with an amine solution in a second compartment in the presence of a second rotating packed bed while rotating the second rotating packed bed to form a CO2- depleted gas and a CCh-rich amine solution, the second rotating packed bed comprising a second packing material having a second average surface area per unit volume that is different from the first average surface area per unit volume, the amine solution having a solution viscosity that is higher than the cooling fluid viscosity; contacting the COi-depleted gas with a wash solution in a third compartment in the presence of a third rotating packed bed while rotating the third rotating packed bed to form a washed exhaust gas, the third rotating packed bed comprising a third packing material having a third average surface area per unit volume different from the second average surface area per unit volume.

4. The method of claim 3, wherein the solution viscosity comprises a dynamic viscosity at 20°C of 20 mPa-s to 200 mPa-s.

5. The method of claim 3 or 4, wherein the cooling fluid viscosity comprises a dynamic viscosity at 20°C of 0.8 mPa-s to 1.5 mPa-s, or wherein the wash solution has a wash solution viscosity comprising a dynamic viscosity at 20°C of 0.8 mPa-s to 1.5 mPa- s, or a combination thereof.

6. The method of any of claims 3 to 5, wherein the liquid to gas weight ratio is 0.1 or more.

7. The adsorber or method of any of the above claims, wherein the first average surface area per unit volume is defined as an average surface area per unit volume within a smallest annular volume containing 95% of the surface area of the packing material in the first compartment, wherein the second average surface area per unit volume is defined as an average surface area per unit volume within a smallest annular volume containing 95% of the surface area of the packing material in the second compartment, and wherein the third average surface area per unit volume is defined as an average surface area per unit volume within a smallest annular volume containing 95% of the surface area of the packing material in the third compartment.

8. The adsorber or method of any of the above claims, wherein the first average surface area per unit volume is greater than the second average surface area per unit volume, or wherein the third average surface area per unit volume is greater than the second average surface area per unit volume, or a combination thereof.

9. The adsorber or method of any of the above claims, wherein the first average surface area per unit volume is greater than the second average surface area per unit volume by 500 m2 / m3or more, or wherein the third average surface area per unit volume is greater than the second average surface area per unit volume by 500 m2 / m3or more, or a combination thereof.

10. The adsorber or method of any of the above claims, wherein an outer gap between an outer radius of the second packed bed and a surface of the second compartment is 40 mm to 150 mm, the outer radius of the second packed bed being defined as the outer radius of the smallest annular volume containing 95% of the surface area of the packing material in the second compartment.

11. The adsorber or method of any of claims 1 - 9, wherein an outer gap between an outer radius of the second packed bed and a surface of the second compartment is 40 mm to 150 mm, the outer radius of the second packed bed being defined as the outer radius of the smallest annular volume containing all of the packing material in the second compartment.

12. The adsorber or method of any of the above claims, wherein an inner gap between an inner radius of the second packed bed and a surface comprising the second liquid inlet is 40 mm to 100 mm, the inner radius of the second packed bed being defined as the inner radius of the smallest annular volume containing 95% of the surface area of the packing material in the second compartment.

13. The adsorber or method of any of claims 1 - 11, wherein an inner gap between an inner radius of the second packed bed and a surface comprising the second liquid inlet is 40 mm to 100 mm, the inner radius of the second packed bed being defined as the inner radius of the smallest annular volume containing all of the packing material in the second compartment.

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