Rotating bed for directly capturing CO2 from air and method thereof

Abstract

A system and method for direct air capture using a rotating sorbent bed configuration is provided. The rotating sorbent bed is supported on a wheel that acts as a frame structure for supporting the sorbent bed. The sorbent bed may include one or more unitary materials that form a support material for the sorbent bed and a sorbent supported on the one or more unitary materials. The rotational path of the sorbent bed passes through a housing that allows sealing a portion of the sorbent bed within the housing. Optionally, the housing may comprise a plurality of sub-zones that facilitate temperature and / or pressure control within the housing while allowing recovery of a high purity CO2 stream from the desorption zone. The rotating sorbent bed configuration can achieve continuous or semi-continuous capture of CO2 while reducing or minimizing contact of the sorbent bed with oxygen at elevated temperatures.

Description

Technical Field

[0001] A system and method for a rotating bed contactor for directly capturing CO2 from air is provided. Background Art

[0002] Capturing and storing CO2 helps reduce or minimize the amount of CO2 emitted into the atmosphere by various commercial, residential, and / or industrial processes. One option is to try to capture CO2 at various types of point sources. Another option is to try to remove CO2 directly from the air.

[0003] One challenge in capturing CO2 directly from the air is the relatively low concentration of CO2 in the atmosphere. Typical atmospheric CO2 concentrations are about 400 vppm. Due to the relatively low concentration of CO2, it is difficult to achieve high CO2 loading at high adsorption rates compared to other components in the air, resulting in increased material costs. In addition, the energy required to capture each CO2 molecule may also be higher, in part because the density of CO2 that typical adsorbents can adsorb is also lower based on the lower concentration of CO2 in the atmosphere. It would be very beneficial if the capital costs and / or energy requirements associated with capturing CO2 could be reduced or minimized.

[0004] There are two basic strategies to manage the multiple gas streams to which the adsorbent is exposed. One strategy is to keep the adsorbent in a fixed volume, corresponding to the adsorbent environment, and then introduce various gas streams into the adsorbent environment in sequence to contact the adsorbent. In this strategy, complex process flow management is required to ensure that the different gas streams do not mix while minimizing the time required to switch between different gas streams. In addition, in order to achieve a continuous CO2 removal process, multiple parallel adsorbent beds are required. Each parallel bed increases the complexity of the piping and manifolds used to manage the process flow.

[0005] Another option is to allow the sorbent to move so that the gas flow can be piped to a fixed location. This simplifies the delivery of the gas flow in a direct air capture process. However, conventional methods of allowing the sorbent to move into the gas flow suffer from various mechanical problems and / or reliability issues. An improved method is needed that simplifies the handling of the gas flow while providing mechanical stability and reliability.

[0006] U.S. Patent 9,925,488 describes a direct air capture system in which multiple monoliths are arranged on a closed loop track. As the monolith moves along the track, CO2 is adsorbed. One location on the track includes a box. If the box is not at the same level as the track, the monolith is moved into the box, sealed inside the box, and then exposed to conditions for CO2 desorption. Continuously removing the monolith from the track and reinserting it into the track may cause mechanical and / or reliability issues. If the box is at the same level as the track, the monolith forms a seal when entering the box, providing a sealed environment for CO2 desorption. Achieving the necessary seal to maintain a separated environment is a challenge. In addition, scaling up this design to a size suitable for commercial-scale CO2 removal may pose structural design challenges.

[0007] European Patent Publication 3725391 describes a direct air capture device that uses vertically arranged adsorbent beds with start / stop motion of sliding doors around the adsorbent beds. The reliability of this design is reduced by the start / stop motion of the adsorbent beds along the linear array, which typically requires hoses and mechanical swivels in a complex ductwork system to accommodate the motion of the adsorbent beds. Equipment that requires such motion is known to be less reliable than permanently installed fixed ducting and equipment. Reliable mechanical swivels are limited to small diameters, so this configuration is further limited because a hose that is fixed at one end and moves at one end cannot complete a 360° rotation without breaking. This explains why equipment of this configuration moves in a straight line rather than a closed loop, thereby increasing process costs due to non-productive time as the adsorbent beds move from one end of the adsorbent bed to the other. It is also noted that this configuration may suffer from sealing issues similar to the design described in U.S. Patent 9,925,488.

[0008] U.S. Patent 11,014,040 describes a horizontal adsorbent bed that is rotated through different zones by a stator. This configuration includes floating seals that use metal bellows or diaphragms to push the seals, which are susceptible to mechanical fatigue failure during thermal cycling (such as the adsorption gas separation process described). The cost of this type of configuration is increased by the use of fluid passages with ports connected to the rotor assembly, which necessarily results in higher pressure drops and more uneven fluid distribution, both of which lead to higher operating costs.

[0009] US Patent 9,227,153 describes a variety of configurations for direct air capture. Some configurations correspond to the use of a thin sheet of adsorbent that oscillates back and forth between being outside and inside a housing. Other configurations involve the use of adsorbent particles that are circulated to achieve cyclic adsorption and desorption of CO2.

[0010] US Patent 8,974,576 describes a rotating monolith with an adsorbent material for adsorbing CO2 from a gas mixture. However, there is no description of a housing for simultaneously exposing different portions of the monolith to adsorption and desorption conditions.

[0011] U.S. Patent 8,052,783 describes a rotating adsorbent for continuous bulk separation of volatile organic carbon from a fluid stream. A majority of the adsorbent is exposed to the fluid stream for adsorbing the volatile organic carbon. A small portion of the adsorbent is located in a desorption zone where a desorption fluid is used to desorb the volatile organics. No structure or means for managing the flow of fluid within the desorption zone is described. Desorption is further facilitated by the use of an electric current in the portion of the rotor that is in the regeneration zone. It should be noted that the use of an electric current is intended to reduce or minimize temperature changes in the rotor as it passes through the desorption zone.

[0012] U.S. Patent 9,120,049 describes a rotary valve assembly for performing a swing adsorption process in a closed environment. Adsorbent materials are arranged in separate sealed chambers. The rotary valve includes a rotor and a stator, both of which have openings. When the openings in the rotor are aligned with the openings in the stator, the valve is "open" and gas can flow into the chamber corresponding to the aligned opening. It should be noted that the delivery of large volumes of fluid through a valve of the type described in this reference may result in additional significant pressure drops.

[0013] US Patent 7,972,422 describes a system corresponding to a closed environment for continuous removal of gas from a gas mixture. A cartridge containing an adsorbent material is used to adsorb H2S from a gas stream. The cartridge can be rotated to achieve adsorption and desorption in a closed environment.

[0014] It should be noted that U.S. Pat. No. 9,120,049 and U.S. Pat. No. 7,972,422 are examples of rotating adsorbent configurations in which the entire adsorbent bed is located within one or more pressure-controlled volumes during operation. This type of configuration is characterized by having multiple valves that control the flow of fluid into the volume containing the adsorbent bed. It should be noted that air can be used as the input gas flow in this configuration. However, in this type of configuration, this air passes through multiple valves and manifolds, so some type of compressor is used to maintain the target flow and pressure combination. Although this type of configuration is effective for maintaining pressure and flow control during the adsorption / desorption cycle, practical considerations limit the potential size or scale of this configuration. For example, as a practical matter, this type of configuration requires valves, such as rotary valves or pop-up valves, to maintain control of fluid flow within the container. The size of commercially available valves of this type is limited. In addition, the pressure drop involved in conveying fluid flow through valves and manifolds results in a large pressure drop at the volume flow rate required for direct air capture. Therefore, even when the target pressure is close to ambient pressure in the volume containing the adsorbent bed, a large amount of compression is required. Summary of the invention

[0015] In one aspect of the present invention, a system for adsorption of CO2 is provided. The system includes an adsorbent bed housing. The system also includes a wheel framework structure within the adsorbent bed housing. The system also includes an adsorbent bed. The adsorbent bed includes a carrier material corresponding to one or more integral materials, and the one or more integral materials are supported by the wheel framework structure. The carrier material also includes a first surface, a second surface, and a plurality of channels, which provide a flow path between the first surface of the carrier material and the second surface of the carrier material. The adsorbent bed also includes an adsorbent selective for the adsorption of CO2 loaded on the carrier material, at least a portion of the adsorbent is loaded on one or more surfaces within the plurality of channels. The system also includes at least one fan or blower associated with the adsorbent bed housing, the at least one fan or blower being in fluid communication with a first portion of the plurality of channels. The system also includes at least one cover plate. The system also includes one or more cover plate seals attached to the one or more cover plates, and the second portion of the plurality of channels is within the desorption zone volume defined by the cover plate and the cover plate seal. According to this aspect, the one or more cover plate seals provide: a) a seal between the at least one cover plate and a first surface of the carrier material, b) a seal between the at least one cover plate and a second surface of the carrier material, or c) a combination of a) and b). The system also includes one or more input flow conduits that provide fluid communication between at least one source of one or more gases and the desorption zone volume. In addition, the system includes at least one output flow conduit in fluid communication with the desorption zone volume.

[0016] On the other hand, a method for adsorbing CO2 is provided. The method includes a rotating wheel frame structure that supports an adsorbent bed, the adsorbent bed including a carrier material, the carrier material including one or more integral materials and an adsorbent that is selective for the adsorption of CO2 loaded on the carrier material. The carrier material also includes a first surface, a second surface, and a plurality of channels that provide a flow path between the first surface of the carrier material and the second surface of the carrier material, and at least a portion of the adsorbent is loaded on the surface within the plurality of channels. The method also includes exposing a first gas stream to a first portion of the adsorbent bed outside the desorption zone volume, the first gas stream containing 15 vol% to 25 vol% O2 and 100 vppm to 650 vppm CO2, the first gas stream having a temperature of 0°C to 40°C. In addition, the method includes exposing the plurality of gas streams to a second portion of the adsorbent bed within a desorption zone volume, the desorption zone volume being defined by at least one cover plate and one or more cover plate seals, the one or more cover plate seals providing: a) a seal between at least one cover plate and a first surface of the support material, b) a seal between at least one cover plate and a second surface of the support material, or c) a combination of a) and b). In some aspects, exposing the plurality of gas streams to the second portion of the adsorbent bed includes sequentially exposing the second portion of the adsorbent bed to: a purge gas stream to form a purge exhaust, and a steam stream having a temperature of 80° C. to 180° C. to form an output stream containing CO2. In various aspects, rotation of the wheeled frame structure changes portions of the adsorbent bed corresponding to a first portion of the adsorbent bed outside the desorption zone volume and a second portion of the adsorbent bed within the desorption zone volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A side view of an exemplary configuration for adsorbing CO2 from a gas stream using an adsorbent bed supported by a rotating wheeled frame structure is shown.

[0018] Figure 2 Shows Figure 1 A top view of a portion of the configuration shown in FIG.

[0019] Figure 3 A perspective view of the rotor assembly and desorption zone cover is shown.

[0020] Figure 4 Shows Figure 3 Exploded view of the configuration shown in .

[0021] Figure 5 An example of a configuration for a desorption zone is shown.

[0022] Figure 6An alternative configuration is shown which includes two adsorbent beds supported on a rotating wheeled frame structure. DETAILED DESCRIPTION

[0023] All numerical values ​​in the detailed description and claims herein are modified by "about" or "approximately", and take into account experimental error and variations that would be expected by a person of ordinary skill in the art.

[0024] Overview

[0025] In various aspects, systems and methods for direct air capture using a rotating adsorbent bed configuration are provided. The rotating adsorbent bed is supported by a wheel, which is used as a support frame for supporting the adsorbent bed. The adsorbent bed can include one or more monolithic materials forming a carrier material of the adsorbent bed and an adsorbent loaded on the monolithic material. The adsorbent bed can be oriented in any convenient manner, such as a horizontal configuration or a vertical configuration. The rotation path of the adsorbent bed passes through a shell that allows sealing of the portion of the adsorbent bed within the shell. Optionally, the shell can include multiple sub-zones that help control the temperature and / or pressure within the shell while allowing a high purity CO2 stream to be recovered from the desorption zone. The rotating adsorbent bed configuration can achieve continuous or semi-continuous capture of CO2 while reducing or minimizing the contact of the adsorbent bed with oxygen at high temperatures.

[0026] Traditionally, direct air capture using a rotating adsorbent bed configuration has faced challenges due to competing considerations. For the adsorption portion of the adsorption / desorption process, due to the low CO2 concentration in the air, a large volume of air needs to be exposed to the adsorbent bed to achieve significant CO2 capture. However, due to the large volume of air that needs to be processed, it is desirable to reduce or minimize the energy required to process air per unit volume. In order to achieve this, it is desirable to reduce or minimize the pressure drop when the air is exposed to the rotating adsorbent bed, thereby reducing or minimizing the air flow power required to maintain contact with the adsorbent bed.

[0027] While the adsorption process benefits from reducing or minimizing restrictions on air flow, there are other considerations for the desorption portion of the adsorption / desorption process cycle. First, the desorption process needs to be conducted in a sufficiently controlled manner to allow for desorption of CO2 while reducing or minimizing the loss of CO2 back to the environment. Second, for certain types of adsorbents (such as certain amine-based adsorbents), the adsorbent material is sensitive to oxygen exposure at elevated temperatures. This is not typically a problem in the adsorption step, but higher temperatures are typically used for desorption. For adsorbents that are sensitive to oxygen exposure at elevated temperatures, the desorption step needs to be adequately isolated from the adsorption step to reduce or minimize degradation of the adsorbent material during the desorption process.

[0028] In various aspects, systems and methods are provided that allow control of the desorption zone environment while reducing or minimizing the energy cost of direct air capture. This is achieved by using a desorption zone housing that is sealed relative to the adsorption zone to allow control of the desorption zone environment. As part of sealing the desorption zone relative to the adsorption zone, a positive pressure is maintained at the seal between the desorption zone and the adsorption zone so that any gas flow across the seal corresponds to gas outflow from the desorption zone to the adsorption zone. Optionally, the desorption zone may correspond to multiple sub-zones. In addition to allowing further control of the desorption zone environment, the use of multiple purge seals within the desorption zone may allow the desorption sub-zone to be a configuration of two or more purge seals away from the adsorption zone. By using a desorption zone housing, air can be exposed to the adsorbent bed using a simplified configuration, thereby reducing or minimizing the required air flow power. Due to the reduced or minimized air flow power requirements, certain aspects may control air flow by using one or more fans, rather than using a blower or compressor with a higher energy input.

[0029] Since the rotating adsorbent bed is a continuous structure, concerns about how to maintain an isolated environment within the shell during the movement of the adsorbent bed are reduced. In particular, since the carrier material of the adsorbent bed is always present, the carrier material (i.e., one or more integral materials) is always close to the seal of the cover plate. This reduces or minimizes the risk of air entering the shell because the sealing condition can be maintained continuously. In addition, a positive pressure can be maintained relative to the outside in the sealed area so that air does not enter the shell. Therefore, the only air delivered to the desorption zone volume is any air in the adsorbent bed itself that is optionally carried into the desorption zone. By controlling the volume of air entering the desorption zone, the flow in the desorption zone can be simplified. The first flow can correspond to a purge gas, which is used to remove any air retained in the rotating wheel when the wheel enters the desorption zone. A second gas (such as steam) flow can then be used to increase the temperature and desorb CO2. Then, before the wheel rotates this part of the adsorbent out of the desorption zone, a cooling gas (such as N2) can be used to restore the adsorbent to a lower temperature. Since substantially the only air in the desorption zone volume corresponds to the air in the adsorbent bed volume when the adsorbent bed enters the zone, the gas flow in the desorption zone can be continuous. It should be noted that there may be additional seals in the desorption zone volume to define different zones or sub-zones in the desorption zone to reduce, minimize or eliminate mixing of various flows in the desorption zone.

[0030] Furthermore, the rotating adsorbent bed can rotate unidirectionally. This avoids the need for additional complexity, such as reciprocating motion and / or some other reverse motion, to move the adsorbent in and out of the housing.

[0031] It should be noted that the above temperature and oxygen management methods are in contrast to conventional designs where a separate adsorbent monolith is moved in and out of the housing. In these comparative designs, air may enter the housing as the monolith is moved in and out of the housing. Therefore, a separate purge step is required to remove air from the housing. In addition, the opening and closing of doors / openings increases the mechanical complexity of the system, resulting in reduced reliability.

[0032] In some aspects, the housing may correspond to a cover plate above and below the adsorbent bed structure. The cover plate may also be referred to as a regeneration plate. The cover plate / regeneration plate provides a portion of the definition of the desorption zone. The desorption zone corresponds to the volume defined by the volume within the seal between the cover plate / regeneration plate and the cover plate / regeneration plate and the rotating adsorbent bed. Typically, the seals on both sides of the adsorbent bed will be aligned, so the volume of the desorption zone is defined based on drawing a connecting line between the seal on one side of the adsorbent bed to the seal on the other side of the adsorbent bed. If the seals are not aligned, the volume of the desorption zone can be identified by starting with the seal on the side of the adsorbent bed that receives the gas flow and then drawing a line parallel to the axis of rotation of the adsorbent bed until the other side of the adsorbent bed is reached. This provides a definition for the portion of the adsorbent bed that is within the desorption zone volume. The portion of the adsorbent bed outside the desorption zone volume is within the adsorption zone. It should be noted that temperature regulation can also be performed within the desorption zone.

[0033] In some aspects, the adsorbent bed can rotate continuously. In this case, the gas flows in the adsorption zone and the desorption zone can be continuous. In this case, the seal of the cover plate can correspond to a "purge" seal, in which part of the sealing function is provided by a higher pressure in the sealing zone (i.e., in the desorption zone). Therefore, the seal can correspond to a non-contact seal, such as a wipe seal, which is close to the surface of the monolithic material but does not contact the surface. By using a non-contact seal, the difficulty of mechanically pushing the seal is avoided. Mechanically pushing the seal will cause the seal to break over time and reduce reliability. In this type of case, the desorption zone can use multiple gas flows, so the adsorbent bed is exposed to multiple gas flows in sequence as it rotates through the desorption zone.

[0034] In other aspects, a contact seal (such as a roller seal) can be used with a continuously rotating adsorbent bed. Although this may reduce the reliability of the seal, this can reduce or minimize the need to use a purge gas at the seal interface. Roller seals and contact wipe seals are examples of seals that can be used in this configuration.

[0035] In other aspects, the adsorbent bed can be rotated in fixed increments so that the adsorbent bed starts and stops moving over a period of time to reposition the portion of the wheel within the desorption zone (i.e., the seal area defined by the cover plate). In this type of case, since the adsorbent bed does not move for a period of time, an inflatable seal or another contact seal (such as a roller seal) can be used. In this type of aspect, a wipe seal can also be used. This can be combined with maintaining a higher pressure in the desorption zone to avoid air from entering the desorption zone. In this type of case, the multiple gas streams used in the desorption zone can be exposed to the adsorbent bed sequentially in time, rather than sequentially in space used during the continuous movement of the rotating adsorbent bed.

[0036] During operation, the portion of the adsorbent bed in the adsorption zone can be exposed to a gas stream (or another gas stream with a low concentration of CO2) to allow CO2 to be adsorbed by the adsorbent loaded on the monolithic material. The portion of the adsorbent bed in the desorption zone is exposed to a) an initial purge gas to remove the air contained in the adsorbent bed when the adsorbent bed enters the desorption zone; b) steam to increase the temperature of the adsorbent bed in the desorption zone and desorb CO2; and c) a temperature regulating gas (such as nitrogen) to cool the monolithic material before the monolithic material leaves the desorption zone. In some aspects, the multiple gas streams can be substantially parallel streams to reduce or minimize mixing. In other aspects, there may be additional seals in the desorption zone to define different zones (or sub-zones) for the adsorbent bed in the desorption zone. For example, additional seals can be used to maintain different sub-zones exposed to steam and temperature regulating gas, respectively. In this discussion, the spatial zones exposed to different gas streams in the desorption zone are defined as sub-zones. Preferably, such sub-zones can be separated by internal seals in the desorption zone to reduce, minimize or eliminate gas mixing within these volumes. The seals may form sub-zones above or below the adsorbent bed.It should be noted that for adsorbent beds constructed from porous materials, some gas mixing between sub-zones may occur within the adsorbent bed.

[0037] In general, the adsorption zone and the desorption zone can have any convenient size, although the adsorption zone generally corresponds to a larger portion of the adsorbent bed than the desorption zone. In various aspects, the volume within the shell defined by the cover plate and the seal (i.e., the desorption zone) can occupy 50 vol% or less, or 40 vol% or less, or 30 vol% or less, or 20 vol% or less, such as as low as 5.0 vol%, and possibly even less, of the volume of the adsorbent bed.

[0038] In various aspects, the systems and methods described herein may have one or more of the following features: 1) In some aspects, a purge seal between the adsorption zone and the desorption zone may cause gas flow from the desorption zone through the seal into the adsorption zone. 2) In some aspects, the housing of the desorption zone may be located within the volume of the adsorption zone. This means that the gas flow (e.g., air) within the adsorption zone may impact at least one surface of the desorption zone, wherein the average flow direction of the gas flow within the adsorption zone is approximately perpendicular to the surface. This is in contrast to a configuration in which, for example, the housing corresponds to the entire height of the partition between the fan or blower and the adsorbent bed, so that the air in the fan or blower does not impact the top surface of the housing. 3) In some aspects, the adsorption zone may be in direct fluid communication with the fan or blower without an intermediate valve between the fan or blower and the adsorption zone. Alternatively, the fan or blower may be in direct fluid communication with the rotating adsorbent bed without an intermediate valve between the fan or blower and the rotating adsorbent bed. 4) In some aspects, where the desorption zone includes a plurality of sub-zones, the desorption sub-zones may be separated from the adsorption zone by at least two purge seals, such as at least one inner seal and one cover seal.

[0039] Adsorbent bed structure and wheel frame structure

[0040] In various aspects, a CO adsorption / desorption process can be performed using an adsorbent bed corresponding to an adsorbent supported on an adsorbent support material (e.g., one or more monolithic materials). The adsorbent bed is supported by a wheeled frame structure that acts as a rotor. The adsorbent bed can be supported on the support material in any convenient manner, such as having an adsorbent supported on the inner surface of a channel passing through the adsorbent support material. The resulting adsorbent bed can provide a high specific surface area for contacting a CO2-containing gas while still allowing air to pass through the adsorbent bed with a reduced or minimized pressure drop.

[0041] One option for providing this type of structure is to use an adsorbent bed that includes a plurality of channels that pass through the adsorbent bed generally parallel to the axis of rotation of the adsorbent bed. The channels may have any convenient shape for supporting the adsorbent material on the inner surface of the channels. Based on packing density considerations, square, rectangular or hexagonal shapes may be beneficial shapes for the channels, but circular or other convenient shapes of channels may also be used.

[0042] The frame structure for supporting the adsorbent bed can correspond to a wheel. The wheeled frame structure can be constructed of any convenient material that provides sufficient structural integrity. Stainless steel (or other types of steel) are examples of suitable materials for forming the frame structure. The carrier material (e.g., one or more integral materials) of the adsorbent bed can be located / placed on the wheeled frame structure. In some aspects, the adsorbent bed can be attached to the wheel. In other aspects, wedges, pins and / or other structures can be used to fix the adsorbent bed in a suitable position within the wheeled frame structure by friction. In some aspects, the wheeled frame structure can also serve as a rotor, with the wheel directly attached / being part of the same component of the shaft for rotating the adsorbent bed. In other aspects, the wheeled frame structure can be mechanically connected to the rotor via one or more gears. It should be noted that if gears are used to rotate the adsorbent bed, the mechanical connection between the gears and the wheeled frame structure can be near the center of the wheel, or gears around the outer edge of the wheeled frame structure can be used.

[0043] One or more monolithic materials corresponding to the adsorbent support material can be composed of materials that give the support material enough structural stability during the rotation of the adsorbent bed. The size of the adsorbent bed can vary, but on a commercial scale, the diameter of the adsorbent bed can be in the range of 1.0 meters to 25 meters, and the thickness (i.e., depth) is in the range of 0.2 meters to 2.0 meters. Suitable materials for forming the monolithic material (or forming multiple parts of the support material that can be assembled into a roughly disc-shaped) can include refractory metal oxides, metals, and ceramics. If the adsorbent bed has enough thickness, some polymer systems may also provide enough structural stability to form an adsorbent bed. Examples of support materials include, but are not limited to, silicon dioxide, aluminum oxide, titanium dioxide, steel (including stainless steel) and silicon carbide.

[0044] Preferably, the support material can be a monolithic material having an adsorbent supported on at least a portion of the surface of the interior of the channel passing through the support material. More generally, one or more monolithic materials used as support materials can form any type of continuous structure that has sufficient structural stability to rotate through the desorption zone. Therefore, support materials that are a combination of multiple smaller monolithic materials (such as fan-shaped sections) can also be used to form the support material of the adsorbent bed. The support material (e.g., a monolithic material, a combination of smaller sections) can preferably have a high density of flow channels or units, such as 20 to 2000 channels per square inch, or 100 to 2000 channels per square inch, or 20 to 1000 channels per square inch, or 100 to 1000 channels per square inch. For example, examples of some types of monolithic materials are commercially available, such as Corning's Monolithic materials. Adsorbents such as amine-based ones can be supported on the inner surfaces of these channels. This type of structure can provide a high surface area of ​​adsorbent while reducing or minimizing the pressure drop as the gas passes through the adsorbent bed.

[0045] After forming the monolithic material, or after forming multiple parts that can be assembled into the support material, the adsorbent can be added to the surface of the support material. For example, a washcoat of an amine-based adsorbent can be applied to the surface of the channel within the monolithic material (or the channel within multiple monolithic material parts). This can provide a relatively uniform adsorbent distribution on the inner surface of the channel. It should be noted that the adsorbent does not need to be introduced into the full length of the channel. The thickness of the adsorbent support material can be selected based in part on structural stability considerations, and the depth of the adsorbent in the channel (i.e., the adsorbent bed) can be any convenient value equal to or less than the thickness of the adsorbent support material channel.

[0046] In this discussion, reference may be made to the leading edge of an adsorbent bed and the trailing edge of an adsorbent bed. The leading edge of an adsorbent bed generally refers to the edge of the adsorbent bed that is first exposed to air (or another CO2-containing stream) when the adsorbent bed is located within the adsorption zone. The trailing edge of the adsorbent bed corresponds to the opposite end of the adsorbent bed.

[0047] Configuration Example

[0048] Figure 1 A cross-sectional view of an embodiment of a configuration for direct air capture using a rotating sorbent bed is shown. Figure 1 The embodiment shown in corresponds to a configuration of a horizontally rotating adsorbent bed. Figure 1 In, a rotor assembly 110 (including a wheeled frame structure) is housed within a rotor housing 101. The rotor assembly 110 provides support for one or more integral materials corresponding to an adsorbent support material 115. A CO2 adsorbent material (e.g., an amine-based adsorbent) is supported on one or more surfaces of the support material 115, such as on the inner surface of a channel passing through the support material 115 in a direction generally perpendicular to the axis of rotation of the adsorbent bed. The CO2 adsorbent material may be supported on the support material 115 in any convenient manner. For example, the adsorbent material may be applied as a coating. In Figure 1 In the illustrated embodiment, the wheeled frame structure / rotor assembly 110 is mounted on the central rotor support 105 , such as by using bearing assemblies 107 .

[0049] exist Figure 1In the exemplary configuration shown, the rotor support 105 rotates the rotor assembly 110, thereby changing the portion of the adsorbent bed contained within the desorption zone 130 over time. In other aspects, movement of the adsorbent bed can be achieved by using gears to mechanically connect the adsorbent bed to the rotor. For example, in another aspect, the center support can be used primarily as a support rather than providing a force for rotating the adsorbent bed. Instead, gears along the outer edge of the frame structure can engage with the frame structure to provide rotation of the adsorbent bed. More generally, any convenient method for rotating the adsorbent bed can be used.

[0050] exist Figure 1 In the illustrated embodiment, the rotor housing 101 includes an upper fan shroud 102 and a lower fan shroud 103. The upper fan shroud 102 and the lower fan shroud 103 help provide a higher degree of laminar air flow within the rotor housing during operation. In other configurations, one or both of the upper fan shroud 102 and the lower fan shroud 103 may be optional. Figure 1 , a fan 108 is shown below the rotor assembly 110 for driving air through the adsorbent bed (e.g., through the channels in the carrier material 115). Depending on the configuration, the fan 108 can optionally be located above the adsorbent bed to pull air through the bed, or at least one fan can be located both above and below the adsorbent bed. Another option is to use ductwork to direct air from the fan to the adsorbent bed. After passing through the adsorbent bed, the air (partially depleted of CO2) exits the upper fan housing 102. Depending on the configuration, any convenient number of fans, blowers, and / or other systems for creating air movement can be used to facilitate air flow through the adsorbent bed (e.g., through the channels in the carrier material 115).

[0051] It should be noted that in Figure 1 In the illustrated embodiment, the diameter of the rotor assembly 110 (and / or the diameter of the adsorbent bed) appears to be smaller than the diameter / length of the rotor housing 101. This is primarily for ease of illustration. Figure 1 . In various aspects, bypass flow of air around the adsorbent bed can be reduced or minimized by matching the size of the adsorbent bed to the rotor housing, and / or by adding additional structural / design features to minimize air flow around the bed. However, it should also be noted that in aspects where air is the gas stream for the adsorption zone, there is less concern about bypass flow of small amounts of CO2 than in applications where flue gas or other high concentration CO2 streams are used as the gas stream for the adsorption zone.

[0052] exist Figure 1In the illustrated embodiment, the desorption zone 130 is a volume defined by the upper regeneration cover 132, the lower regeneration cover 138, and seals (not shown) between the support material 115 and the upper and lower regeneration covers 132 and 138. To minimize or prevent the entry of gas from outside the desorption zone into the desorption zone (other than air carried into the desorption zone within the adsorbent bed 115), in some aspects, the seals for the upper and lower regeneration covers 132 and 138 can be aligned.

[0053] exist Figure 1 In the illustrated embodiment, the flow within the desorption zone 130 is countercurrent relative to the flow outside the desorption zone. In other words, outside the desorption zone 130, air moves through the adsorbent bed 115 from bottom to top. Within the desorption zone 130, multiple flows move through the adsorbent bed 115 from top to bottom. In other aspects, parallel flow inside and outside the desorption zone can be used. In still other configurations, countercurrent flow can be used, wherein the flow in the adsorption zone moves from top to bottom, while the flow in the desorption zone moves from bottom to top. It should also be noted that the adsorbent bed can be mounted in any other convenient manner. For example, the adsorbent bed can be mounted in a vertical orientation so that the axis of rotation is perpendicular to the direction of gravity.

[0054] exist Figure 1 In the illustrated embodiment, the desorption zone 130 includes at least one gas distribution manifold 142 and at least one collection manifold 148. The gas distribution manifold 142 provides a variety of gases used in the desorption zone. Depending on the aspect, these gases may include one or more of the following: a) an initial seal purge gas 153 for maintaining a positive pressure in the desorption zone relative to the volume outside the desorption zone; b) steam 155 for heating the adsorbent bed 115 to promote CO2 desorption; c) a temperature regulating gas 157 (e.g., N2) for cooling the adsorbent bed 115 after CO2 desorption; and d) a final seal purge gas for maintaining a positive pressure in the desorption zone relative to the volume outside the desorption zone. Generally speaking, the flow in the desorption zone includes at least steam and a temperature regulating gas. In various aspects, where air may be carried into the desorption zone within the wheel, an initial purge gas may also be present, both for maintaining a positive pressure in the desorption zone relative to the volume outside the desorption zone and for purging any air (oxygen-containing gas) within the wheel before exposing the loaded adsorbent to the steam.

[0055] The collection manifold 148 can collect the fluid flow passing through the channels in the support material 115. The first collection manifold and / or the first portion of the collection manifold can collect air exhausted from the adsorbent bed during the purge gas flow 153. The second collection manifold and / or the second portion of the collection manifold can collect steam, liquid water, and CO2 during the steam flow 155. It should be noted that part of the heat transfer from the steam to the adsorbent bed during desorption is based on the condensation of the steam. Therefore, there is usually some liquid water in the product of the desorption zone, even if liquid water is not introduced. Optionally, separate manifolds / collection tanks can be provided for the separate collection of liquid products (water) and gas phase products (water vapor and CO2), which leave the adsorbent bed during exposure to the steam flow 155. In some preferred aspects, liquid water is not introduced into the desorption zone as part of the steam flow so as to limit the possibility of water forming a continuous liquid phase over the width of the channel, which may limit the flow of air flowing through the channels in the support material 115. The collected liquid water, steam and CO2 output 165 produced during the steam flow 155 can be further processed in any convenient manner. For example, separation can be performed to recover CO2 as a higher purity stream. The CO2 can then be stored and / or used as an input for another process. The third collection manifold and / or the third portion of the collection manifold can collect the output stream produced during the exposure of the temperature-regulating gas 157 to the adsorbent bed for cooling the bed. Due to the water evaporated from the bed during the cooling step, the output stream can generally have a higher water vapor content than the initial water vapor content of the temperature-regulating gas. The evaporation of water also helps in cooling the bed.

[0056] exist Figure 1 In the exemplary configuration shown, various components may be in fluid communication. Figure 1 14, the input streams 153, 155, and 157 are in fluid communication with the desorption zone 130 via the upper manifold 142. The upper manifold 142 is in direct fluid communication with the desorption zone 130. The input streams 153, 155, and 157 are in indirect fluid communication with the desorption zone 130. As another example, the channels in the support material 115 (and therefore, the adsorbent bed) can be in direct fluid communication with the fan 108. Other examples of direct and indirect fluid communication are described herein and illustrated in the accompanying drawings.

[0057] Figure 2 Shows Figure 1 A plan view (top view) of the configuration shown in FIG. Figure 2 As shown, a majority of the adsorbent bed (and therefore a majority of the support material 115) is located within the adsorption zone 270, and a smaller portion of the adsorbent bed is located within the desorption zone 130. As the adsorbent bed rotates, the portion of the support material 115 within the desorption zone 130 changes over time. Figure 2In the illustrated view, the upper regeneration cover 132 and the upper manifold 142 are shown. Due to the top view, the lower regeneration cover and the lower manifold are shown in FIG. Figure 2 Not shown in . Figure 2 Also shown is an input flow conduit 250. One or more input flow conduits 250 may be used to provide various input streams to the upper manifold 142. Similar conduits (not shown) may be used to carry product or effluent away from the lower manifold.

[0058] Figure 3 A perspective view of the rotor assembly 110, the carrier material 115, and the upper regeneration cover 132 is shown. The upper regeneration cover 132 defines the Figure 1 The upper volume of the desorption zone 130.

[0059] Figure 4 Shows Figure 3 Exploded view of the configuration shown in . Figure 4 1 to illustrate the location of the seal 432 between the upper regeneration cover 132 and the rotor assembly 110 / carrier material 115. Similarly, a seal may be provided between the lower regeneration cover and the rotor assembly / carrier material.

[0060] Operation of the adsorption zone

[0061] During the operation of the rotating adsorbent bed, the process can generally be divided into a process in the adsorption zone and a process in the desorption zone.

[0062] In the adsorption zone, the adsorbent bed is exposed to a gas stream containing CO2. In various aspects, the gas stream containing CO2 is air. More typically, the gas stream containing CO2 can be a gas stream having a CO2 content of 650 vppm or less, or 500 vppm or less, or 400 vppm or less, such as as low as 50 vppm or possibly even less.

[0063] Air also contains O2. Air typically contains about 20 vol% O2. However, the gas stream containing CO2 may contain other amounts of O2. In some aspects, the gas stream containing CO2 may contain 10 vol% to 25 vol%, or 15 vol% to 25 vol% O2. For this type of CO2-containing stream, the rotating wheel adsorption device described herein can provide O2 that reduces or minimizes accidental entry into the desorption zone, thereby reducing or minimizing the possibility of degradation of the adsorbent material during the desorption process. In other aspects, the gas stream containing CO2 may have any convenient O2 content. In optional aspects, the gas stream containing CO2 may have 1.0 vol% or less, or 0.1 vol% or less O2.

[0064] In various aspects, the length of the adsorption process is determined in part by the rotation speed of the adsorbent bed. In other words, for a given portion of the adsorbent bed, the adsorption process begins when that portion of the adsorbent bed exits the desorption zone and continues until the adsorbent bed re-enters the desorption zone. Thus, the duration of the adsorption process can be selected based on the speed of the rotating wheel.

[0065] In some aspects, based on the temperature of the adsorbent and the CO2 concentration in the air, the adsorption process can be carried out for a time sufficient to approach the equilibrium loading. In other aspects, the initial adsorption can be stopped when it is far from the equilibrium loading. For example, one of the difficulties in fully loading the adsorbent with CO2 during the direct air capture process is that the rate of adsorption decreases as the loading approaches the equilibrium loading. One option can be to end the initial adsorption step when the rate of adsorption falls below a target amount. The target amount can be an absolute adsorption rate, an adsorption rate corresponding to a percentage of the adsorption rate at the beginning of the initial adsorption, an adsorption rate corresponding to a percentage of the adsorption rate of the fully desorbed adsorbent, or another convenient target rate. Another option can be to carry out the initial adsorption step for a period of time. For example, selecting a fixed time can be used as a representative of selecting a target adsorption rate without the need for in-situ detection of the adsorption rate.

[0066] During the adsorption process, the adsorbent bed may be at a temperature between 0°C and 70°C, or between 0°C and 40°C, or between 0°C and 30°C, or between 10°C and 60°C, or between 10°C and 40°C, or between 10°C and 30°C. It should be noted that when the adsorbent bed initially leaves the desorption zone, the adsorbent bed may still be at a temperature between 40°C and 70°C because the adsorbent bed is only partially cooled before leaving the desorption zone. Because the rate of adsorption of CO2 from the air is relatively slow, the heating of the adsorbent bed due to CO2 adsorption is also relatively low compared to the ability of the air to transfer heat away from the adsorbent bed. Therefore, in some aspects, the temperature of the adsorbent bed will tend to balance with the temperature of the air or other CO2-containing stream during the adsorption process. In other aspects, a sufficiently low air flow rate and / or a sufficiently high adsorbent bed rotation speed may be used so that the adsorbent bed is not balanced with the air temperature during the adsorption process.

[0067] When the stream containing CO passes through the adsorbent bed, the average gas velocity or superficial gas velocity (superficial gas velocity) of the stream containing CO in the direction of the flow channel of the adsorbent bed can be between 0.02m / s and 0.5m / s, or between 0.02m / s and 0.2m / s, or between 0.05m / s and 0.5m / s, or between 0.05m / s and 0.2m / s. In some aspects, the temperature of the stream containing CO can be between 0°C and 40°C, or 0°C to 30°C, or 10°C to 40°C, or 10°C to 30°C. Such a temperature roughly corresponds to the temperature of ambient air. In other aspects, heated or cooled air streams can be used, as long as the condensation of water on the bed is reduced, minimized or avoided during the adsorption process. The adsorption process can usually be carried out at a pressure close to ambient conditions (about 100kPa-a). Thus, a typical pressure range for the adsorption zone may be 90 kPa-a to 120 kPa-a, or 90 kPa-a to 110 kPa-a. However, operation at near ambient pressure is primarily due to cost and / or convenience. If desired, pressures between 50 kPa-a to 10 MPa-a or even higher may be used.

[0068] Operation of the desorption zone

[0069] In various aspects, one or more gas streams can be used in the desorption zone to promote the desorption of at least a portion of the CO2 adsorbed on the portion of the adsorbent bed in the desorption zone. The one or more gas streams can also be used for temperature management, including increasing the temperature of the adsorbent bed to the desorption temperature. Optionally, additional temperature control streams can be used to cool the adsorbent bed before the adsorbent bed leaves the desorption zone. Optionally, one or more additional gas streams can be used so that at the boundary between the adsorption zone and the desorption zone (e.g., in a sealed position), the pressure in the desorption zone is greater than the pressure outside the desorption zone.

[0070] Figure 5 An example of the interior of the desorption zone is shown. An adsorbent bed section 530 is located within the desorption zone. Seals 533 on both sides of the adsorbent bed section 530 help minimize air from entering the desorption zone. The portion of the adsorbent bed corresponding to the adsorbent bed section 530 changes as the rotating wheel rotates during the adsorption / desorption process.

[0071] Figure 5 The example of the desorption zone shown in includes four sub-zones. Sub-zone 582 corresponds to the initial purge sub-zone. Sub-zone 584 corresponds to the desorption sub-zone. Optional sub-zone 586 corresponds to the temperature adjustment sub-zone. Optional sub-zone 588 corresponds to another purge sub-zone.

[0072] In some aspects, a sub-zone can represent a general volume and / or portion of an adsorbent bed in which a corresponding gas flow is introduced into a desorption zone. Optionally, one or more additional internal seals can be used such that one or more of the sub-zones are separated by additional internal seals. Due to the gas flow present in the desorption zone 530, such internal seals can also correspond to purge seals. In some aspects, an internal seal can exist between each sub-zone in the desorption zone 530. As an example, in Figure 5 , additional seals 591, 593, and 595 are shown dividing the desorption zone 530 into sub-zones 582, 584, 586, and 588. These internal seals can help maintain temperature and / or pressure differences between the sub-zones.

[0073] Optionally, a similar seal can be used below the adsorbent bed portion 530 to create a sub-zone (not shown) below the adsorbent bed. Creating a separate sub-zone below the bed can be beneficial in forming a CO2 product stream that contains a reduced or minimized amount of nitrogen and / or other gases used as a purge or temperature adjustment stream. Because the freezing points of water and CO2 are very different, water can be relatively easily removed from a gas stream containing water and CO2. By reducing or minimizing the presence of other gases that are less likely to freeze than water, subsequent processing of the collected CO2 can be simplified to form a high-purity CO2 stream.

[0074] In some aspects where seals are used, the gas flow rates can be independently selected so that the relative pressures within subzones 582, 584, 586, and 588 can have any convenient relationship. In some aspects where seals are used, the gas flow rate in desorption subzone 584 can be lower than the gas flow rate in subzones 582 and / or 586 so as to reduce or minimize leakage of CO2 from the high CO2 concentration product formed by subzone 584 to the low CO2 concentration product formed by subzone 582 and / or subzone 586.

[0075] The gas flow in sub-zone 582 corresponds to a purge flow. Nitrogen can be used as a purge flow, or any other convenient gas flow with an O2 concentration of 650 vppm or less (or 400 vppm or less, for example, reduced to substantially no O2 content) can be used. The purge flow in sub-zone 582 can achieve two functions. First, when the adsorbent bed rotates, the adsorbent bed portion 530 will generally contain a certain amount of air, which is in the flow channel of the adsorbent bed. The purge flow in sub-zone 582 allows the air brought into the desorption zone in the adsorbent bed to be discharged before the adsorbent bed is heated. Secondly, the purge flow in sub-zone 582 can be used to generate a positive pressure difference relative to the pressure in the adsorption zone on the other side of the seal 533. The portion of the purge gas flow in sub-zone 582 that passes through the channel of the rotating wheel and leaves from the opposite surface can be referred to as the purge flow exhaust.

[0076] The temperature of the gas stream in subzone 582 can be any convenient temperature between 0°C and 50°C, or 10°C to 40°C. One option can be to use a temperature similar to the ambient temperature to minimize the cost of providing the gas stream in subzone 582. The average gas velocity or superficial gas velocity of the channel through the adsorbent bed in subzone 582 can generally be greater than the gas velocity of the channel through the adsorbent bed in the adsorption zone. In some aspects, the gas velocity of the channel through the adsorbent bed in subzone 582 can be between 0.04m / s and 5.0m / s, or 0.04m / s to 2.2m / s, or 0.1m / s to 5.0m / s, or 0.1m / s to 2.2m / s. By using a higher gas velocity in subzone 582 relative to the gas velocity of the CO2-containing gas (e.g., air) in the adjacent part of the adsorption zone, a higher pressure can be maintained in the desorption zone. In some aspects, the pressure within the desorption zone (or at least within sub-zone 582 of the desorption zone) can be 0.15 kPa or more, or 0.5 kPa or more, or 1.0 kPa or more, such as up to 15 kPa or possibly even higher, higher than the pressure within the adsorption zone.

[0077] The gas stream in sub-zone 584 corresponds to the steam for promoting the desorption of CO2 from the adsorbent bed. This results in the formation of a gas stream containing CO2 that leaves from the channel of the rotating wheel. Preferably, the input gas stream in sub-zone 584 can basically only contain steam (less than 3.0vol% of other gases, or less than 1.0vol% of other gases), but in some optional aspects, the steam stream can contain other gases, such as nitrogen. Steam provides heat to increase the temperature of the adsorbent bed to the target temperature for desorption. In addition to the heat directly transferred from the gas phase steam flow, based on the condensation of steam on the adsorbent surface, additional heat can be transferred to the adsorbent. This can allow the temperature of the adsorbent bed to be increased to 70°C to 200°C, or 80°C to 200°C, or 100°C to 200°C, or 70°C to 170°C in at least a portion of the desorption zone (e.g., at least a portion of sub-zone 584). The steam used to heat the adsorbent bed can be at a sufficient temperature so that the steam is substantially completely in the gas phase before entering the channel of the adsorbent bed. At a pressure of about 100 kPa-a, this would correspond to having the steam at a temperature of 100°C or higher. More generally, the temperature of the steam may be from 90°C to 200°C, or from 100°C to 200°C, or from 120°C to 200°C. Preferably, the steam stream is substantially free of liquid water prior to entering the adsorbent bed. This may correspond to having less than 0.1 wt% of the steam stream correspond to liquid water droplets.

[0078] The steam also acts as a sweep gas for carrying the desorbed CO2 into the collection manifold. The average gas velocity or superficial gas velocity of the steam passing through the channels of the adsorbent bed in sub-zone 584 can generally be similar to the gas velocity of the channels of the adsorbent bed in sub-zone 582. In some aspects, the gas velocity of the steam passing through the channels of the adsorbent bed in sub-zone 584 can be between 0.04m / s and 5.0m / s, or 0.04m / s to 2.2m / s, or 0.1m / s to 5.0m / s, or 0.1m / s to 2.2m / s. In some aspects in which sub-zone 582 is separated from sub-zone 584 by a seal, the average gas flow velocity of the steam passing through the channels of the adsorbent bed in sub-zone 584 can be lower than the average gas flow velocity of the channels of the adsorbent bed in sub-zone 582.

[0079] The gas flow in sub-zone 586 corresponds to a temperature regulating flow. Nitrogen and air are examples of gases suitable for temperature regulating flow. The portion of the temperature regulating gas flow in sub-zone 586 that passes through the channel of the rotating wheel and exits from the opposite surface can be referred to as the temperature regulating flow exhaust.

[0080] With respect to water content, evaporative cooling can occur for a temperature-conditioning stream having any convenient water content, as long as the water content of the temperature-conditioning stream is below the vapor pressure of water at the temperature of the temperature-conditioning stream. During the time the adsorbent bed is exposed to the temperature-conditioning stream in subzone 586, the adsorbent bed will have a temperature higher than that of the temperature-conditioning stream. Thus, even if the temperature-conditioning stream is initially saturated, heat transfer from the bed to the temperature-conditioning stream will raise the temperature of the gas, thereby allowing some evaporative cooling to occur.

[0081] In some aspects, the temperature regulating stream can correspond to a "dry" temperature regulating stream. Using a dry temperature regulating stream can increase the amount of evaporative cooling that occurs during exposure of the temperature regulating stream to the adsorbent bed. One way to specify a "dry" gas stream is to specify the humidity of the gas stream at the temperature of the gas stream. In such aspects, the humidity of the gas stream (relative to the temperature of the gas stream) can be 50% or less, or 40% or less, or 30% or less, or 20% or less, such as as low as substantially no humidity. Additionally or alternatively, the temperature regulating stream can contain 10 vol% or less, or 5.0 vol% or less, or 1.0 vol% or less of H2O, such as as low as substantially no water content.

[0082] The temperature regulating stream may have a temperature of 0°C to 60°C, or 0°C to 50°C, or 10°C to 60°C, or 10°C to 40°C before entering the passage of the adsorbent bed. The temperature regulating stream may provide two types of cooling for the adsorbent bed based on the low humidity of the temperature regulating stream. In addition to direct heat transfer from the gas phase stream, the adsorbent bed may also be cooled by evaporating water in the liquid phase present on the adsorbent bed. As described above, liquid water may be present on the adsorbent bed due to condensation of steam during the steam desorption step in subzone 584.

[0083] The average gas velocity or superficial gas velocity of the temperature regulating flow through the channels of the adsorbent bed in sub-zone 586 can be generally similar to the gas velocity through the channels of the adsorbent bed in sub-zone 582. In some aspects, the gas velocity of the temperature regulating flow through the channels of the adsorbent bed in sub-zone 586 can be between 0.04 m / s and 5.0 m / s, or between 0.04 m / s and 2.2 m / s, or between 0.1 m / s and 5.0 m / s, or between 0.1 m / s and 2.2 m / s. In some aspects where sub-zone 586 and sub-zone 584 are separated by a seal, the average gas flow velocity through the channels of the adsorbent bed in sub-zone 584 can be lower than the average gas flow velocity through the channels of the adsorbent bed in sub-zone 586.

[0084] In some aspects, the temperature regulating flow can be used as the final purge gas for the desorption zone. In other aspects, a second optional purge gas flow can be provided in the optional sub-zone 588. Independent of the conditions required to provide a positive pressure relative to the adsorption zone within the edge of the desorption zone, the use of a second purge gas flow can allow the temperature and speed of the temperature regulating flow to be selected. If a separate second purge gas is provided in the optional sub-zone 588, the gas velocity of the second purge gas flow passing through the channel of the adsorbent bed in the sub-zone 588 can be between 0.04m / s and 5.0m / s, or 0.04m / s and 2.2m / s, or 0.1m / s and 5.0m / s, or 0.1m / s and 2.2m / s. The temperature of the second purge gas can be between 0°C and 60°C, or 0°C and 50°C, or 10°C and 60°C, or 10°C and 40°C.

[0085] The temperature adjustment flow and any optional second purge gas flow can be used to reduce the temperature of the adsorbent bed before exiting the desorption zone. This can enable the temperature of the adsorbent bed within at least a portion of the desorption zone (e.g., at least a portion of subzones 586 and / or 588) to be reduced to a temperature of 10°C to 70°C, or 10°C to 50°C, or 30°C to 70°C.

[0086] It should be noted that the combination of the steam flow in partition 584, the temperature regulating flow in partition 586, and optionally the second purge flow in partition 588 will produce a temperature distribution within the desorption zone in which the portion of the adsorbent bed in partition 584 has a higher temperature than the portion of the adsorbent bed in partition 582, partition 586, or optional partition 588.

[0087] Adsorbent materials

[0088] The adsorbent bed of the rotating wheel may correspond to a monolithic material (or assembly of smaller components) for loading an adsorbent such as an amine-based adsorbent. Typically, the adsorbent may be an adsorbent that provides adsorption of CO2 under temperature and pressure conditions close to ambient conditions (e.g., about 0°C to 40°C and a pressure of about 90kPa-a to 110kPa-a). Such an adsorbent is defined herein as an adsorbent that is selective for adsorption of CO2. The adsorbent may be loaded on the monolithic material in any convenient manner. One option may be to impregnate the monolithic material / other support structure with an amine adsorbent compound and / or a polymer. This may allow the amine adsorbent to be incorporated onto the surface and / or into the pores of a porous support structure. Another option may be to chemically bond the adsorbent to the surface of the support structure. Yet another option may be to form a polymer layer (e.g., a polymer layer having amine functional groups) having CO2 adsorption capacity in situ on the inner surface of the channel of the support structure. Yet another option may be to incorporate the adsorbent into a support layer applied to a support structure, such as by incorporating the adsorbent into an alumina layer deposited on the surface of the support structure.

[0089] A variety of amines have the potential to serve as adsorbents for CO2 capture. Some amines may correspond to polymers with amine functionality, such as polyethyleneimine and / or polypropyleneimine. Polyethyleneimine, polypropyleneimine, or a combination thereof are examples of amine systems that can be deposited on and / or impregnated onto the surface of a monolith. Another example of an amine is 3-aminopropyltrimethoxysilane. For monoliths with an appropriate number of oxygen functional groups on the surface of the monolith, this type of amine can be grafted onto the surface of the monolith.

[0090] Other examples of adsorbent materials include, but are not limited to, metal organic framework materials (MOFs) and materials having a zeotype framework structure. It is noted that the adsorption capacity of some MOFs and zeotype adsorbents can be modified and / or enhanced by adding amine adsorbents to the MOF or zeotype.

[0091] Alternative Configurations - Variations of Adsorbent Beds

[0092] Figure 2-4 An example of an adsorbent bed structure is generally shown. Figure 1 It is shown that the adsorbent bed (e.g. Figure 2-4 In one embodiment, the adsorbent bed in the adsorption device is incorporated into an adsorption device, wherein a single adsorbent bed is used in a horizontal direction. In other aspects, other configurations of the adsorption device can be used.

[0093] An alternative configuration is to use an adsorbent bed that is mounted in an orientation other than substantially horizontal relative to the direction of gravity. For example, in some aspects, the adsorbent bed can be mounted in a vertically oriented wheeled frame structure so that the direction of gravity pull is approximately perpendicular to the axis of rotation of the adsorbent bed. In other aspects, any convenient orientation of the adsorbent bed / wheeled frame structure can be used. Since most of the flow in the adsorbent bed is gas phase flow and has sufficient initial velocity, the operation of the adsorption and desorption zones of the vertically mounted adsorbent bed can be substantially similar to that of the horizontally mounted adsorbent bed. It is worth noting that any liquid water formed by condensation of steam may require different treatment methods. One option for handling liquid water is to set the desorption zone at the bottom of the adsorbent bed relative to the direction of gravity. This can simplify the placement of a collection tank at an appropriate location within the desorption zone for collecting any liquid water discharged from the adsorbent bed.

[0094] Figure 6 Another alternative configuration is shown in which two adsorbent beds are used. Figure 6 In the exemplary configuration shown, the rotor housing 601 includes a rotor assembly 610 (including a support material 615 for supporting an adsorbent) and a rotor assembly 620 (including a support material 625 for supporting an adsorbent). Figure 6 In the illustrated embodiment, the fan or blower 608 is not located above or below the bed, but is located on one side of the rotor assembly 610 and the rotor assembly 620. In other aspects, the fan or blower 608 can be in any convenient location, and a duct system can be used to provide fluid communication between the fan or blower 608 and the adsorbent bed. The fan or blower 608 forces air into the volume between the adsorbent beds 615. The partition wall 604 is an inner wall of the rotor housing 601 that reduces, minimizes or eliminates the gap between the rotor assemblies 610 and 620 and the nearest wall. Therefore, the airflow is forced to pass through the channels in the carrier material 615 and the carrier material 625, thereby reducing or minimizing the ability to bypass the adsorbent bed. The gas streams 653 (nitrogen purge), 655 (steam) and 657 (temperature adjustment flow) for the desorption zone can also be introduced between the beds so that a single flow source for each gas stream can provide gas flow for two adsorbent beds. The product output stream 665 from the adsorbent on the support material 615 can be recovered separately from the product output stream 667 from the adsorbent on the support material 625. A manifold for managing the input and output streams to the adsorbent bed can be used, such as a manifold similar to Figure 1 It is noted that although the lower regeneration head corresponds to the inlet flow side of the upper adsorbent bed, the lower regeneration head of the upper adsorbent bed may include a sump.

[0095] Additional Configuration - Discontinuous Motion of Rotating Adsorbent Bed

[0096] In some aspects, the adsorbent bed can be moved in discontinuous amounts with pauses between movements, rather than continuously rotating the adsorbent bed. By moving and stopping the adsorbent bed in discontinuous amounts, additional processing options can be achieved. In particular, moving the adsorbent bed in discontinuous amounts can allow the use of seals that form a complete sealing contact with the surface of the adsorbent's load material. Inflatable seals are an example of this type of seal. By using an inflatable seal or another type of seal that provides a complete sealing contact with the load material, a greater pressure difference can be achieved between the desorption zone and the adsorption zone. This allows the desorption zone to use a pressure of less than 100 kPa-a to assist the desorption of CO2.

[0097] During the discontinuous movement of the adsorbent bed (and its corresponding wheeled frame structure), the adsorbent bed can be rotated by any convenient amount during each movement step. In some aspects, the size of each movement step can match the size of the portion of the adsorbent bed located in the desorption zone. In other words, in one movement step, the portion of the adsorbent bed in the desorption zone is completely moved into the adsorption zone. In other aspects, discontinuous movement steps can be used to move the portion of the adsorbent bed from the desorption zone into the adsorption zone. In this regard, multiple discontinuous movement steps are required to move the portion of the bed in the desorption zone into the adsorption zone. Of course, moving the portion of the bed in the desorption zone into the adsorption zone will also cause another portion of the adsorbent bed to move from the adsorption zone into the desorption zone.

[0098] In operation, the steps of the adsorption / desorption process are similar, and the operation in the adsorption zone can be basically the same as when the adsorbent bed is continuously moved. However, in the case of discontinuously moving adsorbent beds, there are many options for the operation mode of the desorption zone.

[0099] One option for operation of the desorption zone during discontinuous movement of the adsorbent bed is to adopt a strategy similar to that used for continuously moving the adsorbent bed. In this case, the desorption zone can still include multiple sub-zones for different gas flows, and seals can be set even within the desorption zone to further define these sub-zones. In this type of aspect, the size of the sub-zones can be substantially uniform, and the size of the movement step of the wheel can match the size of the sub-zone. Optionally, the size of one or more sub-zones can be a multiple of the size of the movement step, rather than the size of each sub-zone being substantially the same as the movement step. In this type of aspect, the process sequence can start with the wheel moving one movement step to a new position. The seal can then engage the surface of the adsorbent bed (such as the surface of the carrier material). Next, the gas flow in the desorption zone can be opened for a period of time. The gas flow is then stopped, the seal is released, and the next movement of the wheel can occur.

[0100] Optionally, when discontinuous movement of the adsorbent bed is used, the gas flow in the desorption zone can be used sequentially rather than simultaneously. In this type of aspect, the adsorbent bed can be moved by a movement step. In some aspects, the movement step will correspond to the size of the desorption zone, so that the entire portion of the adsorbent bed in the desorption zone is moved to the position of the adsorption zone. This will also result in a new portion of the adsorbent bed in the desorption zone. However, other types of movement steps can also be used. After the movement step, the seal engages with the surface of the adsorbent bed. The gas flow sequence of the desorption step can then be applied to all adsorbent bed portions in the desorption zone. In various aspects, this can mean exposing the portion of the adsorbent bed in the desorption zone to an initial purge gas flow; a desorption gas flow; an optional second purge gas flow; and an optional temperature adjustment gas flow. These gas flows can be similar to the gas flows described herein. The difference is the order in which all adsorbent beds are exposed to the gas flow, rather than exposing different sub-zones of the adsorbent bed to each gas flow at the same time.

[0101] Where the adsorbent bed is moved in discrete amounts and a seal engaging the surface is used, a greater pressure differential can be maintained between the desorption zone volume and the adsorption zone. In this regard, optionally, during at least a portion of the desorption step, the pressure within the desorption zone volume can be 10 kPa or more, or 20 kPa or more, or 40 kPa or more lower than the pressure in the adsorption zone (i.e., outside the desorption zone volume), for example, up to 99 kPa or possibly more lower than the pressure in the adsorption zone.

[0102] Other Embodiments

[0103] Embodiment 1. A system for adsorbing CO2, comprising:

[0104] Adsorbent bed housing;

[0105] a wheeled frame structure within the adsorbent bed housing;

[0106] An adsorbent bed, the adsorbent bed comprising:

[0107] a carrier material comprising one or more monolithic materials supported by the wheeled frame structure, the carrier material comprising a first surface, a second surface, and a plurality of channels, the plurality of channels providing a flow path between the first surface of the carrier material and the second surface of the carrier material, and

[0108] an adsorbent, the adsorbent being selective for adsorption of CO2 supported on the support material, at least a portion of the adsorbent being supported on surfaces within the plurality of channels;

[0109] at least one fan or blower associated with the sorbent bed housing, the at least one fan or blower being in fluid communication with a first portion of the plurality of channels;

[0110] at least one cover plate;

[0111] one or more cover plate seals attached to the one or more cover plates, a second portion of the plurality of channels being within a desorption zone volume defined by the at least one cover plate and the one or more cover plate seals, the one or more cover plate seals providing: a) a seal between the at least one cover plate and the first surface of the carrier material, b) a seal between the at least one cover plate and the second surface of the carrier material, or c) a combination of a) and b);

[0112] one or more input flow conduits providing fluid communication between at least one source of one or more gases and the desorption zone volume; and

[0113] At least one outlet flow conduit is in fluid communication with the desorption zone volume.

[0114] Embodiment 2. According to the system of embodiment 1, it also includes at least one internal seal within the desorption zone volume, and the at least one internal seal provides a seal between the inner surface of the cover plate and at least one of the first surface and the second surface of the carrier material, and the at least one internal seal defines a plurality of sub-zones within the desorption zone volume.

[0115] Embodiment 3. A system according to embodiment 2, wherein at least one first input flow conduit among the one or more input flow conduits is connected to a first sub-zone fluid of the multiple sub-zones within the desorption zone volume, and wherein at least one second input flow conduit among the one or more input flow conduits is connected to a second sub-zone fluid of the multiple separate sub-zones within the desorption zone volume.

[0116] Embodiment 4. The system of embodiment 2 or 3, wherein at least one sub-zone within the desorption zone volume is separated from the first portion of the plurality of channels by at least one internal seal and at least one cover plate seal.

[0117] Embodiment 5. The system of any of the above embodiments, wherein the one or more cover plate seals comprise one or more purged seals, or wherein the one or more cover plate seals comprise one or more inflatable seals.

[0118] Embodiment 6. A system according to any one of the above embodiments, wherein the one or more input flow conduits are connected to the desorption zone volume fluid via at least one input manifold; or wherein the at least one output flow conduit is connected to the desorption zone volume fluid via at least one output manifold; or a combination thereof, optionally, the at least one output manifold includes a liquid collection tank.

[0119] Embodiment 7. A system according to any of the above embodiments, wherein the wheeled frame structure is supported by a central support, and the central support is optionally configured to rotate the wheeled frame structure via a motor.

[0120] Embodiment 8. A system according to any of the above embodiments, wherein the wheeled frame structure is mechanically engaged by one or more gears, and the one or more gears are configured to rotate the wheeled frame structure.

[0121] Embodiment 9. The system of any of the above embodiments, wherein the first portion of the plurality of channels is in direct fluid communication with the at least one fan or blower.

[0122] Embodiment 10. A method of adsorbing CO2 using the system according to any one of embodiments 1 to 9, comprising:

[0123] rotating the wheeled frame structure;

[0124] exposing a first gas stream to a first portion of the adsorbent bed outside the desorption zone volume, the first gas stream comprising 15 vol% to 25 vol% O2 and 100 vppm to 650 vppm CO2, the first gas stream having a temperature of 0°C to 40°C;

[0125] Exposing multiple gas flows to a second portion of the adsorbent bed within the desorption zone volume, exposing multiple gas flows to the second portion of the adsorbent bed includes exposing the second portion of the adsorbent bed in sequence to: a purge gas flow to form a purge exhaust gas, and a steam flow having a temperature of 80°C to 180°C to form an output flow containing CO2, wherein the rotation of the wheeled frame structure changes the portion of the adsorbent bed corresponding to the first portion of the adsorbent bed outside the desorption zone volume and the second portion of the adsorbent bed inside the desorption zone volume.

[0126] Embodiment 11. The method of embodiment 10, wherein the desorption zone volume comprises a plurality of sub-zones, each sub-zone comprising at least one of the plurality of gas flows.

[0127] Embodiment 12. A method according to embodiment 10 or 11, wherein after the exposure to the steam flow, the temperature of the leading edge of the second portion of the adsorbent bed is 70°C or higher, and before being rotated out of the desorption zone volume, the temperature of the trailing edge of the second portion of the adsorbent bed is 60°C or lower.

[0128] Embodiment 13. A method according to any one of the above embodiments, wherein exposing the plurality of gas streams to the second portion of the adsorbent bed further comprises exposing the second portion to a temperature regulating stream after the steam stream, the temperature regulating stream having a temperature of 0°C to 50°C to form a temperature regulating stream exhaust gas, and optionally, exposing the plurality of gas streams to the second portion of the adsorbent bed further comprises exposing the second portion of the adsorbent bed to a second purge gas stream after the temperature regulating stream, the temperature regulating stream optionally comprising a humidity of 25% or less relative to the temperature of the temperature regulating stream.

[0129] Embodiment 14. The method of any one of embodiments 10 to 13, wherein exposing the second portion of the adsorbent bed to the vapor stream further forms a liquid output product, or wherein the vapor stream contains substantially no liquid water content, or a combination thereof.

[0130] Embodiment 15. A method according to any one of embodiments 10 to 14, wherein the pressure inside the desorption zone volume is greater than the pressure outside the desorption volume by 2.0 kPa or more, or wherein the pressure inside the desorption zone volume is lower than the pressure outside the desorption zone volume by 20 kPa or more, or a combination thereof.

[0131] Additional Embodiments A. The method of any one of Embodiments 10 to 15, wherein exposing the second portion of the adsorbent bed to the plurality of gas streams comprises exposing the second portion of the adsorbent bed to the plurality of gas streams sequentially in time.

[0132] Additional embodiment B. The method of any one of embodiments 10 to 15, wherein the first gas stream comprises air.

[0133] Another embodiment C. A method according to any one of embodiments 10 to 15, wherein the first gas flow impacts at least one surface of at least one cover plate in the desorption zone, and the average flow direction of the first gas flow in the adsorption zone is substantially perpendicular to the at least one surface of the at least one cover plate in the desorption zone.

[0134] Additional embodiment D. The method of any one of embodiments 10 to 15, wherein rotating the wheeled frame structure comprises rotating the wheeled frame structure continuously.

[0135] Certain features have been described using a set of numerical upper limits and a set of numerical lower limits. It should be appreciated that, unless otherwise indicated, ranges from any lower limit to any upper limit are contemplated. Certain lower limits, upper limits, and ranges appear in one or more claims below. All numerical values ​​take into account experimental errors and variations that would be expected by a person of ordinary skill in the art.

[0136] The foregoing description of the present disclosure illustrates and describes the present method. In addition, the present disclosure shows and describes exemplary methods, but it should be understood that various other combinations, modifications and environments can be adopted, and the present method can be changed or modified within the scope of the concepts expressed herein with the above teachings and / or the skill or knowledge of the relevant field.

Claims

1. A system for adsorbing CO2, comprising: Adsorbent bed housing; a wheeled frame structure within the adsorbent bed housing; An adsorbent bed, the adsorbent bed comprising: a carrier material comprising one or more monolithic materials supported by the wheeled frame structure, the carrier material comprising a first surface, a second surface, and a plurality of channels, the plurality of channels providing a flow path between the first surface of the carrier material and the second surface of the carrier material, and an adsorbent, the adsorbent being selective for adsorption of CO2 supported on the support material, at least a portion of the adsorbent being supported on surfaces within the plurality of channels; at least one fan or blower associated with the sorbent bed housing, the at least one fan or blower being in fluid communication with a first portion of the plurality of channels; at least one cover plate; one or more cover plate seals attached to the one or more cover plates, a second portion of the plurality of channels being within a desorption zone volume defined by the at least one cover plate and the one or more cover plate seals, the one or more cover plate seals providing: a) a seal between the at least one cover plate and the first surface of the carrier material, b) a seal between the at least one cover plate and the second surface of the carrier material, or c) a combination of a) and b); one or more input flow conduits providing fluid communication between at least one source of one or more gases and the desorption zone volume; and At least one outlet flow conduit is in fluid communication with the desorption zone volume.

2. The system according to claim 1 further includes at least one internal seal within the desorption zone volume, wherein the at least one internal seal provides a seal between the inner surface of the cover plate and at least one of the first surface and the second surface of the carrier material, and the at least one internal seal defines a plurality of sub-zones within the desorption zone volume.

3. A system according to claim 2, wherein at least a first input flow conduit of the one or more input flow conduits is connected to a first sub-zone fluid of the plurality of sub-zones within the desorption zone volume, and wherein at least a second input flow conduit of the one or more input flow conduits is connected to a second sub-zone fluid of the plurality of separate sub-zones within the desorption zone volume.

4. The system of claim 2 or 3, wherein at least one sub-zone within the desorption zone volume is separated from the first portion of the plurality of channels by at least one internal seal and at least one cover plate seal.

5. The system of any of the preceding claims, wherein the one or more cover plate seals comprise one or more purged seals, or wherein the one or more cover plate seals comprise one or more inflatable seals.

6. A system according to any of the above claims, wherein the one or more input flow conduits are connected to the desorption zone volume fluid via at least one input manifold; or wherein the at least one output flow conduit is connected to the desorption zone volume fluid via at least one output manifold; or a combination thereof, optionally, the at least one output manifold includes a liquid collection tank.

7. The system of any of the preceding claims, wherein the wheeled frame structure is supported by a central support, the central support optionally being configured to rotate the wheeled frame structure via a motor.

8. The system of any of the preceding claims, wherein the wheeled frame structure is mechanically engaged by one or more gears configured to rotate the wheeled frame structure.

9. The system of any of the preceding claims, wherein the first portion of the plurality of channels is in direct fluid communication with the at least one fan or blower.

10. A method of adsorbing CO2 using the system according to any one of embodiments 1 to 9, comprising: rotating the wheeled frame structure; exposing a first gas stream to a first portion of the desorption zone volume of the adsorbent bed, the first gas stream comprising 15 vol% to 25 vol% O2 and 100 vppm to 650 vppm CO2, the first gas stream having a temperature of 0°C to 40°C; Exposing multiple gas streams to a second portion of the adsorbent bed within the desorption zone volume, exposing multiple gas streams to the second portion of the adsorbent bed includes exposing the second portion of the adsorbent bed in sequence to: a purge gas stream to form a purge exhaust gas, and a steam stream having a temperature of 80°C to 180°C to form an output stream containing CO2, wherein the rotation of the wheeled frame structure changes the portion of the adsorbent bed corresponding to the first portion of the adsorbent bed outside the desorption zone volume and the second portion of the adsorbent bed inside the desorption zone volume.

11. The method of claim 10, wherein the desorption zone volume comprises a plurality of sub-zones, each sub-zone containing at least one of the plurality of gas streams.

12. The method of claim 10 or 11, wherein after said exposure to said steam flow, the temperature of the leading edge of said second portion of said adsorbent bed is 70°C or greater, and before being rotated out of said desorption zone volume, the temperature of the trailing edge of said second portion of said adsorbent bed is 60°C or less.

13. The method according to any one of claims 10 to 12, wherein exposing the plurality of gas streams to the second portion of the adsorbent bed further comprises exposing the second portion to a temperature regulating stream after the steam stream, the temperature regulating stream having a temperature of 0°C to 50°C to form a temperature regulating stream exhaust gas, and optionally, exposing the plurality of gas streams to the second portion of the adsorbent bed further comprises exposing the second portion of the adsorbent bed to a second purge gas stream after the temperature regulating stream, the temperature regulating stream optionally comprising a humidity of 25% or less relative to the temperature of the temperature regulating stream.

14. The process of any one of claims 10 to 13, wherein exposing the second portion of the adsorbent bed to the vapor stream further forms a liquid output product, or wherein the vapor stream contains substantially no liquid water content, or a combination thereof.

15. The method of any one of claims 10 to 14, wherein the pressure inside the desorption zone volume is 2.0 kPa or more greater than the pressure outside the desorption zone volume, or wherein the pressure inside the desorption zone volume is 20 kPa or more less than the pressure outside the desorption zone volume, or a combination thereof.

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