Hybrid carbon capture system with sorbent capture state

Abstract

A first subsystem receives a gas flow comprising a first concentration of carbon dioxide. The first subsystem separates the gas flow into a rich stream and a lean stream by a first carbon capture process. The rich stream includes a second concentration of carbon dioxide greater than the first concentration. The lean stream includes a third concentration of carbon dioxide less than the first concentration. A second subsystem receives the lean stream from the first subsystem. A carbon adsorption system removes at least a portion of the carbon dioxide from the rich stream, resulting in a depleted stream. A flow separator separates the depleted stream into a stack stream and a recycling stream. A carbon desorption system releases the portion of the carbon dioxide into the recycling stream. The recycling stream is directed to mix with at least one of the gas flow or the rich stream.

Description

TITLEHYBRID CARBON CAPTURE SYSTEM WITH SORBENT CAPTURE STATECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63 / 600,008, filed November 16, 2023 which is incorporated herein by reference in its entirety.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] This invention was made using U.S. government funding through the U.S. Department of Energy contract Nos. DE-SC-0011885, DE-FE-0031603, and DE0FE0007580. The government has certain rights in this invention.BACKGROUND OF THE DISCLOSURE

[0003] Fossil fuel combustion results in the emissions of carbon dioxide (CO2) and other greenhouse gases. The electric power generation industry is one of the largest CO2 emitters, although other sources of CO2 exist, such as lime kilns to generate cement. During the combustion of fossil fuels, such as in electric power plants for the generation of electricity, flue gas from a furnace, boiler, or engine is emitted through one or more stacks and to the atmosphere. The flue gas includes one or more pollutants, such as nitrogen, oxygen, water vapor, carbon dioxide, and other pollutants, including sulfur oxides, nitrogen oxides, and particulate matter. Carbon dioxide is also present in natural gas or biogas generated from anaerobic digesters. The CO2 is conventionally removed from such materials to increase the concentration of methane for subsequent use.

[0004] Carbon capture and storage (CCS) involves capturing carbon dioxide from large point sources, such as power plants, and storing it underground or using it for other purposes, such as enhanced oil recovery or chemical production. CCS can help reduce greenhouse gas emissions and mitigate climate change.

[0005] Methods of CSS include CO2 separation from other materials (e.g., postcombustion gases, natural gas, biogas, or other sources) include chemical and physicalsolvent processes, chemical absorption, physical absorption, membrane separation with CO2 selective membranes, and cryogenic methods. For example, chemical absorption includes absorbing the CO2 in an aqueous solution including an alkanolamine (e.g., monoethanolamine (MEA), diethanolamine (DEA), methyldiethanolamine (MDEA)) to form a CCh-amine complex and subsequently releasing the absorbed CO2 from the CO2- amine complex via steam stripping during a regeneration process.

[0006] CO2 collection is often incentivized through so-called “carbon credits,” or permissions or licenses to generate carbon dioxide. Such carbon credits are often purchased or traded between companies. Carbon dioxide emitters may seek to reduce their carbon emissions, freeing them up to sell to other companies and / or reducing their purchase from the government.SUMMARY

[0007] In some aspects, the techniques described herein relate to a carbon capture system including a first subsystem configured to receive a gas flow including a first concentration of carbon dioxide. The first subsystem is configured to separate the gas flow into a rich stream and a lean stream by a first carbon capture process. The rich stream includes a second concentration of carbon dioxide greater than the first concentration. The lean stream includes a third concentration of carbon dioxide less than the first concentration. A second subsystem is configured to receive the lean stream from the first subsystem. The second subsystem a carbon adsorption system to remove at least a portion of the carbon dioxide from the rich stream, resulting in a depleted stream. A flow separator separates the depleted stream into a stack stream and a recycling stream. A carbon desorption system releases the portion of the carbon dioxide into the recycling stream. The recycling stream is directed to mix with at least one of the gas flow or the rich stream.

[0008] In some aspects, the techniques described herein relate to a method for carbon capture. At a first carbon capture subsystem, a carbon capture system separates a gas flow into a rich stream and a lean stream. The rich stream has a higher concentration of carbon dioxide than the lean stream. At a second carbon capture subsystem, the carbon capture system adsorbs at least a portion of carbon dioxide in the lean stream, resulting in a depleted stream. At the second carbon capture subsystem, the carbon capture system desorbs at leasta part of the portion of the carbon dioxide into a recycling stream. The recycling stream is diverted from the depleted stream. The carbon capture system recycles the recycling stream as an input to the first carbon capture subsystem or the rich stream.

[0009] In some aspects, the techniques described herein relate to a method for carbon capture. The carbon capture system directs a gas stream through a first carbon capture system. The first carbon capture system separates the gas stream into a rich stream and a lean stream. The carbon capture system directs the lean stream through a second carbon capture system. The second carbon capture system removes residual carbon dioxide from the lean stream resulting in a depleted stream. The carbon capture system releases at least part of the residual carbon dioxide from the second carbon capture system into a recycling stream. The recycling stream has a lower carbon dioxide concentration than the lean stream. The carbon capture system directs the recycling stream to at least one of the gas stream or the rich stream.

[0010] This summary is provided to introduce a selection of concepts that are further described in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter. Additional features and aspects of embodiments of the disclosure will be set forth herein, and in part will be obvious from the description, or may be learned by the practice of such embodiments.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to describe the manner in which the above-recited and other features of the disclosure can be obtained, a more particular description will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. For better understanding, the like elements have been designated by like reference numbers throughout the various accompanying figures. While some of the drawings may be schematic or exaggerated representations of concepts, at least some of the drawings may be drawn to scale. Understanding that the drawings depict some example embodiments, the embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

[0012] FIG. 1 is a schematic representation of a carbon capture system, according to at least one embodiment of the present disclosure.

[0013] FIG. 2 is a representation of a carbon capture system, according to at least one embodiment of the present disclosure.

[0014] FIG. 3 is a representation of a carbon capture system, according to at least one embodiment of the present disclosure.

[0015] FIG. 4 is a representation of a carbon capture system, according to at least one embodiment of the present disclosure.

[0016] FIG. 5 is a representation of a carbon capture system, according to at least one embodiment of the present disclosure.

[0017] FIG. 6 is a representation of a carbon capture system, according to at least one embodiment of the present disclosure.

[0018] FIG. 7 is a flowchart of a method for carbon capture, according to at least one embodiment of the present disclosure.

[0019] FIG. 8 is a flowchart of a method for carbon capture, according to at least one embodiment of the present disclosure.DETAILED DESCRIPTION

[0020] This disclosure generally relates to devices, systems, and methods for CCS systems. The system includes two stages, including a bulk CO2 removal stage using a membrane or a solvent, and a residual CO2 removal stage using a solid-state sorbent. The system can achieve a very high CO2 capture efficiency and a low cost of CO2 capture. The first stage may receive a CO2-laden input stream, such as a flue gas or other exhaust from a CO2- producing process. The first stage may separate the input stream into a rich stream and a lean stream. The rich stream has a higher carbon dioxide concentration than the lean stream. The rich stream may be directed to additional carbon dioxide processing systems, such as additional CO2 separation systems, a CO2 collection system, and so forth.

[0021] The lean stream may be directed to a second stage. The second stage may remove residual carbon dioxide from the lean stream. The residual carbon dioxide may then be released into a recycling stream. The recycling stream may be diverted to a CO2 processing subsystem having a carbon capture process. For example, the recycling stream may bemixed with the input stream to the first stage. In some examples, the recycling stream may be mixed with the rich stream output from the first stage. In some examples, the recycling stream may be mixed with the input stream for additional CO2 removal stages. In some examples, the recycling stream may be mixed with the input stream for a CO2 concentration and / or collection system. Utilizing the recycling stream may increase the total amount of carbon dioxide collected by the carbon capture system. For example, recycling at least a portion of the carbon dioxide back into the carbon capture system may prevent the recycled carbon dioxide from being exhausted out the stack. This may reduce the amount of emitted carbon dioxide.

[0022] In accordance with at least one embodiment of the present disclosure, the first stage uses a membrane contactor to separate CO2 from the input gas stream. The membrane contactor may output a permeate stream having a high concentration of carbon dioxide and a retentate stream having a low concentration of carbon dioxide. The C Ch-depleted retentate stream is sent to the second stage for further purification.

[0023] The second stage may utilize a multi-bed, solid-state sorbent contactor to remove the residual CO2 from the retentate stream. In some embodiments, the sorbent material is regenerated by using a low-concentration CO2 stream and / or a vacuum. The sorbent contactor may be any type of sorbent contactor, such as a radial-type bed that allows a low pressure-drop and a high sorbent utilization. The bed can operate in either a centripetal or a centrifugal manner, and can support counter-current flow for regeneration. The desorbed CO2 may be diverted or directed to different points of the membrane carbon capture process. For example, the desorbed CO2 may be directed to different locations based on the purge pressure, or the pressure at which the CO2 is desorbed from the sorbent material. For example, the desorbed CO2 may be combined with the CCh-enriched permeate stream output from the membrane of the first stage. In this manner, at least one embodiment of a carbon capture system described herein may send the recaptured residual carbon dioxide back through the carbon capture system, thereby increasing the total amount of carbon dioxide captured by the carbon capture system.

[0024] FIG. 1 is a schematic representation of a carbon capture system 100, according to at least one embodiment of the present disclosure. The carbon capture system 100 includes a carbon dioxide source 102. The carbon dioxide source 102 may include any type ofcarbon dioxide source. For example, the carbon dioxide source 102 may include one or more of a coal-fired boiler, a natural gas-fired boiler, a lime kiln, any other CO2 source, and combinations thereof. The output of the carbon dioxide source 102 may be any type of output, such as a flue gas or an input gas flow 104.

[0025] The input gas flow 104 may have an input CO2 concentration. In some embodiments, the input CO2 concentration may be in a range having an upper value, a lower value, or upper and lower values including any of 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, 16%, 18%, 20%, 25%, or any value therebetween. For example, the input CO2 concentration may be greater than 1%. In another example, the input CO2 concentration may be less than 25%. In yet other examples, the input CO2 concentration may be any value in a range between 1% and 25%. In some embodiments, it may be critical that the input CO2 concentration is between 10% and 20% to efficiently separate the carbon dioxide from the carbon dioxide source 102 during bulk CO2 removal. For example, natural gas power plants may provide an input CO2 concentration between approximately 3 to 5%, coal-fired plants may provide an input CO2 concentration of between approximately 10 to 12%, waste-to-energy plants may provide an input CO2 concentration of between approximately 9 to 13%, cement plants may provide an input CO2 concentration of between approximately 17 to 25%, and steel plants may provide an input CO2 concentration of between approximately 20 to 30%

[0026] The input gas flow 104 may be directed to first carbon capture subsystem 106 such that the first carbon capture subsystem 106 may receive the input gas flow 104 as an input. The first carbon capture subsystem 106 may include a first carbon capture process that includes a bulk CO2 removal system. For example, the first carbon capture subsystem 106 may receive a gas stream (e.g., the input gas flow 104) having relatively a high concentration of CO2 and separate the gas stream into a rich stream 108 and a lean stream 110. The rich stream 108 may have a higher carbon dioxide concentration than the lean stream 110.

[0027] The first carbon capture subsystem 106 and the first carbon capture process may include any type of bulk CO2 removal system. For example, the first carbon capture process may include a membrane system. The membrane system may include any type ofmembrane system, such as a carbon dioxide selective polymer membrane, zeolite-based ceramic membranes, any other membranes, and combinations thereof.

[0028] The input gas flow 104 may be directed through the membrane in the first carbon capture subsystem 106 with a membrane pressure. The membrane pressure of the input gas flow 104 may facilitate the separation of the carbon dioxide across the membrane. In some embodiments, the membrane pressure may be in a range having an upper value, a lower value, or upper and lower values including any of 1.0 bar, 1.1 bar, 1.2 bar, 1.3 bar, 1.4 bar, 1.5 bar, 1.6 bar, 1.7 bar, 1.8 bar, 1.9 bar, 2.0 bar, or any value therebetween. For example, the membrane pressure may be greater than 1.0 bar. In another example, the membrane pressure may be less than 2.0 bar. In yet other examples, the membrane pressure may be any value in a range between 1.0 bar and 2.0 bar. In some embodiments, it may be critical that the membrane pressure is between 1.1 bar and 1.5 bar to efficiently separate carbon dioxide from the input gas flow 104. In some embodiments, a vacuum may be pulled on the permeate stream through the membrane, thereby increasing a pressure differential between the input and permeate streams. For example, the permeate stream may have a vacuum pressure of 0.8 atm, 0.6 atm, 0.5 atm, 0.2 atm, or less, such that the pressure differential is between approximately 25% to 1000%, approximately 50% to 750%, or between approximately 100% to 500% across the membrane.

[0029] The rich stream 108 may be diverted or directed to a carbon collection system 112. The carbon collection system 112 may further process the rich stream 108 for transportation and / or storage. For example, the carbon collection system 112 may include a cryogenic purification system. In some examples, the carbon collection system 112 may include a CO compression system. In some examples, the carbon collection system 112 may include any purification, processing, compression, transportation, storage, sequestration, or other collection system. In some examples, the carbon collection system 112 may include additional carbon capture subsystems to further concentrate or refine the carbon dioxide concentration of the rich stream 108.

[0030] The lean stream 110 may be directed to a second carbon capture subsystem 114 such that the second carbon capture subsystem 114 receives the lean stream 110 as an input. The second carbon capture subsystem 114 may include a second carbon capture process that collects the residual carbon dioxide located in the lean stream 110. For example, the- 1 -second carbon capture process may separate the residual carbon dioxide from the lean stream 110, resulting in a depleted stream 116. The depleted stream 116 may have a depleted concentration of CO2. In some embodiments, the depleted concentration may be in a range having an upper value, a lower value, or upper and lower values including any of 100 ppm, 200 ppm, 300 ppm, 400 ppm, 500 ppm, 600 ppm, 700 ppm, 800 ppm, 900 ppm, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, or any value therebetween. For example, the depleted concentration may be greater than 100 ppm. In another example, the depleted concentration may be less than 1.0%. In yet other examples, the depleted concentration may be any value in a range between 100 ppm and 1.0%. In some embodiments, it may be critical that the depleted concentration is less than 400 ppm to reduce the amount of emitted concentration and not increase the total amount of carbon dioxide in the atmosphere. In some embodiments, the depleted stream 116 may exhausted to the atmosphere. For example, the depleted stream 116 may be sent to a stack 118.

[0031] The second carbon capture subsystem 114 may release the captured carbon dioxide for use within the carbon capture system 100. For example, the second carbon capture subsystem 114 may release the captured carbon dioxide into a recycling stream (collectively 120). The recycling stream 120 may be diverted or directed to one or more locations in the carbon capture system 100. For example, a first recycling stream 120-1 may be directed to the input gas flow 104. The first recycling stream 120-1 may be mixed with the input gas flow 104 and then processed by the first carbon capture subsystem 106. In this manner, the residual carbon dioxide from the lean stream 110 may be re-processed by the first carbon capture subsystem 106, resulting in increased carbon capture by the carbon capture system 100 and reduced emissions out of the stack 118.

[0032] In some embodiments, a second recycling stream 120-2 may be directed to the rich stream 108. The second recycling stream 120-2 may be mixed with the rich stream 108 and then processed by the carbon collection system 112. In this manner, the residual carbon dioxide from the lean stream 110 may be collected and processed or stored by the carbon collection system 112, thereby increasing the carbon capture by the carbon capture system 100 and reduced emissions of the stack 118.

[0033] In some embodiments, the recycling stream 120 may be directed to the input gas flow 104 and / or the rich stream 108 based on the carbon dioxide concentration of therecycling stream 120. For example, a carbon dioxide concentration that is the same as or approximately the same as the input gas flow 104 may cause the recycling stream 120 to be directed to the input gas flow 104. In some examples, the carbon dioxide concentration of the recycling stream 120 may be greater than the input gas flow 104. Mixing the recycling stream 120 having the same as or higher carbon dioxide concentration as the input gas flow 104 may not reduce the concentration of the input gas flow 104. In some examples, the recycling stream 120 may increase the carbon dioxide concentration of the input gas flow 104, thereby improving the efficiency of the first carbon capture subsystem 106.

[0034] In some examples, a carbon dioxide concentration that is the same as or approximately the same as the rich stream 108 may cause the recycling stream 120 to be directed to the rich stream 108. In some examples, the carbon dioxide concentration of the recycling stream 120 may be greater than the rich stream 108. Mixing the recycling stream 120 having the same as or higher carbon dioxide concentration as the rich stream 108 may not reduce the concentration of the rich stream 108. In some examples, the recycling stream 120 may increase the carbon dioxide concentration of the rich stream 108, thereby improving the efficiency of the carbon collection system 112.

[0035] FIG. 2 is a representation of a carbon capture system 200, according to at least one embodiment of the present disclosure. The carbon capture system 200 includes a carbon dioxide source 202. The carbon dioxide source 202 may generate an input gas flow 204 having an input CO2 concentration.

[0036] A first carbon capture subsystem may include a first carbon capture process that includes a carbon separation membrane 222. The carbon separation membrane 222 may be a bulk carbon dioxide removal system, outputting a rich stream 208 (e.g., a permeate stream) and a lean stream 210 (e.g., a retentate stream). The rich stream 208 may be directed to a carbon collection system 212. The carbon collection system 212 may include one or more of further carbon dioxide refinement, purification, concentration, compression, or other carbon dioxide processing systems.

[0037] The lean stream 210 may be directed to a second carbon capture subsystem having a second carbon capture process that includes a carbon sorbent 224. The carbon sorbent 224 may include any carbon sorbent that may adsorb carbon dioxide. The carbon sorbent224 may include a mesoporous material and may be formed of and include carbon, nitrogen, and oxygen and may be referred to herein as a “mesoporous carbon sorbent.” The carbon sorbent 224 may include one or more additional elements, such as phosphorous or sulfur. In some embodiments, the carbon sorbent 224 is pelletized and configured for use in a vacuum swing adsorption system or a vacuum swing adsorption system for selectively capturing CO2 from a gas stream, such as a post-combustion gas stream.

[0038] The carbon sorbent 224 may include a carbon adsorption system 226 and a carbon desorption system 228. In the carbon adsorption system 226, the carbon sorbent 224 may adsorb at least a part of the residual carbon dioxide from the lean stream 210. This may result in a depleted stream 216 having a depleted concentration, as discussed herein.

[0039] In the carbon desorption system 228, the carbon sorbent 224 may desorb the part or a part of the part of the residual carbon dioxide adsorbed by the carbon adsorption system 226. The carbon desorption system 228 may desorb the carbon dioxide into a recycling stream 220. In the embodiment shown, the recycling stream 220 may be directed to the input gas flow 204. The recycling stream 220 may be mixed with the input gas flow 204 upstream of the carbon separation membrane 222. Mixing the recycling stream 220 with the input gas flow 204 upstream of the carbon separation membrane 222 may allow the 222 to separate the residual carbon dioxide adsorbed by the carbon adsorption system 226 and desorbed by the carbon desorption system 228 into the recycling stream 220. This may facilitate the capture of carbon dioxide that would otherwise be exhausted out of a stack 218.

[0040] The carbon desorption system 228 may desorb the carbon dioxide into a clean stream 230. The clean stream 230 may have a low concentration of carbon dioxide. For example, the clean stream 230 may have a concentration of carbon dioxide that is lower than the lean stream 210. In some examples, the clean stream 230 may have the depleted concentration. In some examples, the clean stream 230 may have a concentration of carbon dioxide that is the same as the depleted concentration as the depleted stream 216. In some examples, the clean stream 230 may have a lower carbon dioxide concentration than the depleted stream 216. In some examples, the clean stream 230 may have a higher carbon dioxide concentration than the depleted stream 216.

[0041] In some embodiments, the clean stream 230 is formed from the depleted stream 216. For example, the depleted stream 216 may be directed to a flow separator 232. The flow separator 232 may divert or direct a stack stream 234 to the stack 218 and the clean stream 230 to the carbon desorption system 228. The clean stream 230 may be a volumetric portion (by volumetric flow rate) of the depleted stream 216. In some embodiments, the volumetric portion may be in a range having an upper value, a lower value, or upper and lower values including any of 1%, 2%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, or any value therebetween. For example, the volumetric portion may be greater than 1%. In another example, the volumetric portion may be less than 40%. In yet other examples, the volumetric portion may be any value in a range between 1% and 40%. In some embodiments, it may be critical that the volumetric portion is between 20% and 40% to increase the concentration of the carbon dioxide released by the carbon desorption system 228.

[0042] The clean stream 230 may have a desorption pressure. The desorption pressure may be the pressure at which the carbon desorption system 228 desorbs the carbon dioxide. In some embodiments, the desorption pressure may be in a range having an upper value, a lower value, or upper and lower values including any of 0.01 bar, 0.05 bar, 0.1 bar, 0.2 bar, 0.3 bar, 0.4 bar, 0.5 bar, 0.6 bar, 0.7 bar, 0.8 bar, 0.9 bar, 1.0 bar, or any value therebetween. For example, the desorption pressure may be greater than 0.01 bar. In another example, the desorption pressure may be less than 1.0 bar. In yet other examples, the desorption pressure may be any value in a range between 0.01 bar and 1.0 bar. In some embodiments, it may be critical that the desorption pressure is between 0.1 to 0.150 bar, or less than 0.2 bar to release the carbon dioxide with a sufficiently high concentration for later separation.

[0043] The carbon desorption system 228 may utilize any type of desorption process. For example, the carbon desorption system 228 may include a heater that may heat the carbon sorbent 224. Heating the carbon sorbent 224 may cause the adsorbed carbon to be released. In some examples the carbon desorption system 228 may include a steam purge, in which heated steam is applied to or passed over the carbon sorbent 224 to release the adsorbed carbon. In some examples, the carbon desorption system 228 may include a vacuum pump which reduces the pressure of the carbon sorbent 224 to a low desorption pressure to releasethe adsorbed carbon. In some examples, the carbon desorption system 228 may include any other process used to desorb carbon dioxide from the carbon sorbent 224.

[0044] FIG. 3 is a representation of a carbon capture system 300, according to at least one embodiment of the present disclosure. The carbon capture system 300 includes a carbon dioxide source 302. The carbon dioxide source 302 may generate an input gas flow 304 having an input CO2 concentration.

[0045] A first carbon capture subsystem may include a carbon separation membrane 322. The carbon separation membrane 322 may be a bulk carbon dioxide removal system, outputting a rich stream 308 (e.g., a permeate stream) and a lean stream 310 (e.g., a retentate stream). The rich stream 308 may be directed to a carbon collection system 312. The carbon collection system 312 may include one or more of further carbon dioxide refinement, purification, concentration, compression, or other carbon dioxide processing systems.

[0046] The lean stream 310 may be directed to a second carbon capture subsystem that includes a carbon sorbent 324. The carbon sorbent 324 may include a carbon adsorption system 326 and a carbon desorption system 328. In the carbon adsorption system 326, the carbon sorbent 324 may adsorb at least a part of the residual carbon dioxide from the lean stream 310. This may result in a depleted stream 316 having a depleted concentration, as discussed herein. The depleted stream 316 may be directed to a flow separator 332 which may separate or divert the depleted stream 316 into a stack stream 334 and a clean stream 330. The stack stream 334 may be exhausted out of a stack 318.

[0047] The carbon desorption system 328 may desorb the adsorbed carbon from the carbon sorbent 324. The carbon desorption system 328 may desorb the adsorbed carbon into a recycling stream 320. In some embodiments, as discussed herein, the carbon desorption system 328 may desorb the adsorbed carbon into the clean stream 330 that is separated from the depleted stream 316. In some embodiments, the carbon desorption system 328 may desorb the adsorbed carbon into a different clean stream to generate the recycling stream 320.

[0048] In accordance with at least one embodiment of the present disclosure, the recycling stream 320 may be directed downstream of the carbon separation membrane 322. For example, the recycling stream 320 may be directed to mix with the rich stream 308downstream of the carbon separation membrane 322. The carbon capture system 300 may include one or more carbon dioxide processing systems downstream of the carbon separation membrane 322. For example, the carbon capture system 300 may include the carbon collection system 312 downstream of the carbon separation membrane 322. The recycling stream 320 may be mixed with the rich stream 308 prior to the carbon collection system 312 purifying, concentrating, compressing, or otherwise processing the carbon dioxide. In this manner, the residual carbon dioxide collected by the carbon sorbent 324 may be further collected and / or processed, thereby increasing the total carbon capture of the carbon capture system 300.

[0049] FIG. 4 is a representation of a carbon capture system 400, according to at least one embodiment of the present disclosure. The carbon capture system 400 includes a carbon dioxide source 402. The carbon dioxide source 402 may generate an input gas flow 404 having an input CO2 concentration.

[0050] A first carbon capture subsystem may include a carbon separation membrane 422. The carbon separation membrane 422 may be a bulk carbon dioxide removal system, outputting a rich stream 408 (e.g., a permeate stream) and a lean stream 410 (e g., a retentate stream). The rich stream 408 may be directed to further processing. For example, the rich stream 408 may be directed to one or more additional carbon capture systems 436. The additional carbon capture systems 436 may further process or separate the carbon dioxide from the rich stream 408 The additional carbon capture systems 436 may include any type of carbon capture system. For example, the additional carbon capture systems 436 may include additional membrane systems, carbon sorbent systems, any other carbon capture systems, and combinations thereof. This may help to increase the concentration of the rich stream 408.

[0051] The additional carbon capture systems 436 may send a second lean stream 438 to the carbon sorbent 424. The residual carbon dioxide in the second lean stream 438 may be adsorbed or otherwise processed by the carbon sorbent 424. The additional carbon capture systems 436 may send a second rich stream 440 to a carbon collection system 412, which may further process, concentrate, compress, or otherwise store the carbon dioxide from the second rich stream 440. As discussed herein, the carbon collection system 412 may includeone or more of further carbon dioxide refinement, purification, concentration, compression, or other carbon dioxide processing systems.

[0052] The lean stream 410 and / or the second lean stream 438 may be directed to a second carbon capture subsystem that includes a carbon sorbent 424. The carbon sorbent 424 may include a carbon adsorption system 426 and a carbon desorption system 428. In the carbon adsorption system 426, the carbon sorbent 424 may adsorb at least part of the residual carbon dioxide from the lean stream 410. This may result in a depleted stream 416 having a depleted concentration, as discussed herein. The depleted stream 416 may be directed to a flow separator 432 which may separate the depleted stream 416 into a stack stream 434 and a clean stream 430. The stack stream 434 may be exhausted out of a stack 418.

[0053] The carbon desorption system 428 may desorb the adsorbed carbon from the carbon sorbent 424. The carbon desorption system 428 may desorb the adsorbed carbon into a recycling stream 420. In some embodiments, as discussed herein, the carbon desorption system 428 may desorb the adsorbed carbon into the clean stream 430 that is separated from the depleted stream 416. In some embodiments, the carbon desorption system 428 may desorb the adsorbed carbon into a different clean stream to generate the recycling stream 420.

[0054] In accordance with at last one embodiment of the present disclosure, the recycling stream 420 may be directed to a location downstream of the carbon separation membrane 422. For example, as discussed herein, the recycling stream 420 may be directed to a location upstream of the additional carbon capture systems 436. The recycling stream 420 may be mixed with the rich stream 408 upstream of the additional carbon capture systems 436. In this manner, the desorbed carbon dioxide in the recycling stream 420 may be further collected or separated by the additional carbon capture systems 436.

[0055] FIG. 5 is a representation of a carbon capture system 500, according to at least one embodiment of the present disclosure. The carbon capture system 500 includes a carbon dioxide source 502. The carbon dioxide source 502 may generate an input gas flow 504 having an input CO2 concentration.

[0056] A first carbon capture subsystem may include a carbon separation membrane 522. The carbon separation membrane 522 may be a bulk carbon dioxide removal system, outputting a rich stream 508 (e.g., a permeate stream) and a lean stream 510 (e.g., aretentate stream). The rich stream 508 may be directed to further processing. For example, the rich stream 508 may be directed to one or more additional carbon capture systems 536. The additional carbon capture systems 536 may further process or separate the carbon dioxide from the rich stream 508 The additional carbon capture systems 536 may include any type of carbon capture system. For example, the additional carbon capture systems 536 may include additional membrane systems, carbon sorbent systems, any other carbon capture systems, and combinations thereof. This may help to increase the concentration of the rich stream 508.

[0057] The additional carbon capture systems 536 may send a second lean stream 538 to the carbon sorbent 524. The residual carbon dioxide in the second lean stream 538 may be adsorbed or otherwise processed by the carbon sorbent 524. The additional carbon capture systems 536 may send a second rich stream 540 to a carbon collection system 512, which may further process, concentrate, compress, or otherwise store the carbon dioxide from the second rich stream 540. As discussed herein, the carbon collection system 512 may include one or more of further carbon dioxide refinement, purification, concentration, compression, or other carbon dioxide processing systems.

[0058] The lean stream 510 and / or the second lean stream 538 may be directed to a second carbon capture subsystem that includes a carbon sorbent 524. The carbon sorbent 524 may include a carbon adsorption system 526 and a carbon desorption system 528. In the carbon adsorption system 526, the carbon sorbent 524 may adsorb at least part of the residual carbon dioxide from the lean stream 510. This may result in a depleted stream 516 having a depleted concentration, as discussed herein. The depleted stream 516 may be directed to a flow separator 532 which may separate the depleted stream 516 into a stack stream 534 and a clean stream 530. The stack stream 534 may be exhausted out of a stack 518.

[0059] The carbon desorption system 528 may desorb the adsorbed carbon from the carbon sorbent 524. The carbon desorption system 528 may desorb the adsorbed carbon into a recycling stream 520. In some embodiments, as discussed herein, the carbon desorption system 528 may desorb the adsorbed carbon into the clean stream 530 that is separated from the depleted stream 516. In some embodiments, the carbon desorption system 528 may desorb the adsorbed carbon into a different clean stream to generate the recycling stream 520.

[0060] In accordance with at last one embodiment of the present disclosure, the recycling stream 520 may be directed to a location downstream of the carbon separation membrane 522. For example, as discussed herein, the recycling stream 520 may be directed to a location upstream of the carbon collection system 512 and downstream of the additional carbon capture systems 536. The recycling stream 520 may be mixed with the second rich stream 540 upstream of the carbon collection system 512. In this manner, the desorbed carbon dioxide in the recycling stream 520 may be further collected by the carbon collection system 512.

[0061] In some embodiments, the recycling stream 520 may be directed to mix with the second rich stream 540 outputted by the additional carbon capture systems 536. This may allow the residual carbon dioxide from the lean stream 510 and / or the second lean stream 538 to be collected by the carbon capture system 500 and not exhausted out of the stack 518. In this manner, the total carbon dioxide capture efficiency of the carbon capture system 500 may be increased.

[0062] FIG. 6 is a representation of a carbon capture system 600, according to at least one embodiment of the present disclosure. The carbon capture system 600 includes a carbon dioxide source 602. The carbon dioxide source 602 may generate an input gas flow 604 having an input CO2 concentration.

[0063] A first carbon capture subsystem 606 may separate the input gas flow 604 into a rich stream 608 and a lean stream 610. The rich stream 608 may be directed to further processing. For example, the rich stream 608 may be directed to one or more additional carbon capture systems 636. The additional carbon capture systems 636 may further process or separate the carbon dioxide from the rich stream 608 The additional carbon capture systems 636 may include any type of carbon capture system. For example, the additional carbon capture systems 636 may include additional membrane systems, carbon sorbent systems, any other carbon capture systems, and combinations thereof. This may help to increase the concentration of the rich stream 408.

[0064] The additional carbon capture systems 636 may send a second lean stream 638 to the second carbon capture system 614. The additional carbon capture systems 636 may send a second rich stream 640 to a carbon collection system 612, which may further process, concentrate, compress, or otherwise store the carbon dioxide from the second richstream 640. As discussed herein, the carbon collection system 612 may include one or more of further carbon dioxide refinement, purification, concentration, compression, or other carbon dioxide processing systems.

[0065] As discussed herein, the lean stream 610 and / or the second lean stream 638 may be directed to a second carbon capture system 614. The second carbon capture system may capture any residual carbon dioxide from the lean stream 610 and / or the second lean stream 638, resulting in a depleted stream 616 that may be exhausted out of a stack 618. The second carbon capture system 614 may release the captured residual carbon dioxide into a recycling stream (collectively 620). The recycling stream 620 may be directed to another carbon capture system or concentration system for further processing. For example, the recycling stream 620 may be directed to mix with an input stream in one or more of the first carbon capture subsystem 606, the additional carbon capture systems 636, or a carbon collection system 612.

[0066] In some examples, a first recycling stream 620-1 may be directed upstream of the first carbon capture subsystem 606 to mix with the input gas flow 604 being inputted to the first carbon capture subsystem 606, In some examples, a second recycling stream 620-2 may be directed downstream of the first carbon capture subsystem 606 and upstream of the additional carbon capture systems 636, to be mixed with the rich stream 608 in putted into the additional carbon capture systems 636. In some examples, a third recycling stream 620- 3 may be directed downstream of the first carbon capture subsystem 606 and the additional carbon capture systems 636 and upstream of the carbon collection system 612 to be mixed with the second rich stream 640 inputted into the carbon collection system 612.

[0067] The recycling stream 620 may be directed to a particular location within the carbon capture system 600 based on any factor. For example, the recycling stream 620 may be directed to the location within the carbon capture system 600 based on the carbon dioxide concentration of the recycling stream 620. In some examples, the recycling stream 620 may be directed to the location within the carbon capture system 600 based on the pressure of the recycling stream 620. In some examples, the recycling stream 620 may be directed to the location within the carbon capture system 600 based on a temperature of the recycling stream 620. In some examples, the recycling stream 620 may be directed to the location within the carbon capture system 600 based on a moisture content of the recycling stream620. In some examples, the recycling stream 620 may be directed to the location within the carbon capture system 600 based on a combination of one or more of carbon dioxide concentration, pressure, temperature, moisture content, any other property, and combinations thereof.

[0068] FIG. 7 and FIG. 8, the corresponding text, and the examples provide a number of different methods, systems, devices, and computer-readable media of the carbon capture system 100. In addition to the foregoing, one or more embodiments can also be described in terms of flowcharts comprising acts for accomplishing a particular result, as shown in FIG. 7 and FIG. 8. FIG. 7 and FIG. 8 may be performed with more or fewer acts. Further, the acts may be performed in differing orders. Additionally, the acts described herein may be repeated or performed in parallel with one another or parallel with different instances of the same or similar acts.

[0069] As mentioned, FIG. 7 illustrates a flowchart of a series of acts or a method 750 for carbon capture, according to at least one embodiment of the present disclosure. While FIG. 7 illustrates acts according to one embodiment, alternative embodiments may omit, add to, reorder, and / or modify any of the acts shown in FIG. 7. The acts of FIG. 7 can be performed as part of a method. Alternatively, a computer-readable medium can comprise instructions that, when executed by one or more processors, cause a computing device to perform the acts of FIG. 7 and / or cause a computing device to instruct the various components discussed herein to perform the acts of FIG. 7. In some embodiments, a system can perform the acts of FIG. 7.

[0070] At a first carbon capture subsystem, a first carbon capture process separates a gas stream into a rich stream and a lean stream at 752. The rich stream has a higher concentration of carbon dioxide than the lean stream. At a second carbon capture subsystem, a second carbon capture process may adsorb at least part of or at least a portion of the carbon dioxide from the lean stream at 754. This may result in a depleted stream having a lower concentration than the lean stream.

[0071] At the second carbon capture subsystem, the second carbon capture process may desorb at least part of the portion of the carbon dioxide into a recycling stream at 756. The recycling stream may be diverted from the depleted stream. The carbon capture systemmay recycle the recycling stream as an input to the first carbon capture subsystem or the rich stream at 758.

[0072] As mentioned, FIG. 8 illustrates a flowchart of a series of acts or a method 860 for carbon capture, according to at least one embodiment of the present disclosure. While FIG. 8 illustrates acts according to one embodiment, alternative embodiments may omit, add to, reorder, and / or modify any of the acts shown in FIG. 8. The acts of FIG. 8 can be performed as part of a method. Alternatively, a computer-readable medium can comprise instructions that, when executed by one or more processors, cause a computing device to perform the acts of FIG. 8 and / or cause a computing device to instruct the various components discussed herein to perform the acts of FIG. 8. In some embodiments, a system can perform the acts of FIG. 8.

[0073] The carbon capture system may direct a gas stream through a first carbon capture subsystem at 862. The first carbon capture subsystem may separate the gas stream into a rich stream and a lean stream. The carbon capture system may direct the lean stream through a second carbon capture subsystem at 864. The second carbon capture subsystem may remove residual carbon dioxide from the lean stream, resulting in a depleted stream.

[0074] The carbon capture system may release at least part of the residual carbon dioxide from the second carbon capture subsystem into a recycling stream at 866. The recycling stream has a lower carbon dioxide concentration than the lean stream. The carbon capture system may direct the recycling stream to at least one of the gas stream or the rich stream.INDUSTRIAL APPLICABILITY

[0075] The first stage of the process may utilize a variety of membrane technologies, including CO2 selective polymer membranes, zeolite-based ceramic membranes. In some embodiments, the first stage of the process may utilize a solvent, including chemical solvents such as amines, alkaline solvents, and physical solvents. The second stage consists of a solid-state CO2 adsorbents, such as carbon sorbents, supported solid amines sorbents, metal-organic-framework sorbents, and combinations thereof. In some embodiments, the CCS may be combined with additional equipment, including such as raw flue gas conditioning systems and CO2 purification and / or compression systems. In some embodiments, the CCS may only include one or more of the first stage and one or more of the second stage.

[0076] The individual stages within the hybrid CCS system include at least a first-stage bulk CO2 removal subsystem and a second-stage residual CO2 removal subsystem. Typical first-stage subsystems include membrane contactors, liquid scrubber towers (MEA, etc.), and solid-state sorbent contactors. The second-stage subsystem may include a solid-state sorbent contactor.

[0077] The hybridization of the bulk removal process (e.g., the first stage) with the sorbent process (e.g., the second stage) enables the operation of the bulk removal process at an increased operating efficiency, which may result in a high CO2 slip. The hybridization with the sorbent will facilitate an increased CO2 capture efficiency.

[0078] The individual stages within the hybrid CCS system include a first-stage bulk CO2 removal subsystem and a second-stage residual CO2 removal subsystem. Typical stage-1 subsystems include membrane contactors, liquid scrubber towers (MEA, etc.), and solid- state sorbent contactors. The preferred second-stage subsystem is a solid-state sorbent contactor.

[0079] The raw flue gas from the point-source emitter may be cleaned to remove particulate and reduce the amount of acid gas present in the flue gas stream. This may be performed to meet the environmental emission requirements and are not directly related to the CCS. The clean flue gas may then be adjusted to match the desired dew point (humidity) and temperature for the stage- 1 subsystem that includes either a membrane or solvent scrubbing technology. For ease of discussion, the membrane system is used to illustrate the technology for the rest of the disclosure, although it should be understood that the techniques of the present disclosure may utilize solvent scrubbing in the stage one system. The flue gas may then be pressurized using a blower or low-pressure compressor and fed to the membrane inlet. The membrane subsystem may perform an initial CO2 separation on the feed stream — resulting in permeate and retentate outlet streams. The permeate stream is CCh-enriched relative to the clean flue gas feed stream while the retentate or residue stream is CO2 depleted.

[0080] The second-stage subsystem, such as multi-bed, solid-state sorbent contactor, receives the retentate or residue stream from the stage-one membrane and removes the residual CO2 from the CCh-depleted flue gas using a regenerable sorbent material. The flue gas may exit the stage-two subsystem as a CCh-free or mostly CO2 stream that can bereleased to the environment, such as using a stack. In accordance with at least one embodiment of the present disclosure, over 98% overall CO2 removal efficiency may be achieved. Once the sorbent material in the contactor has become saturated with CO2, the bed may be switched to a regeneration mode and fresh (regenerated) bed is brought online so that continuous flue gas processing is possible.

[0081] The saturated bed may then be regenerated by sweeping the CO2 adsorbed on the sorbent using a low-concentration CO2 stream and / or in conjunction with a lower than ambient regeneration pressure (vacuum). Typical desorption sweep gases include nitrogen rich (e.g., CO2 depleted) flue gas that exits the stage-two subsystem, ambient air, or low- pressure steam. Pressure reduction may be obtained using an industrial vacuum pump to evacuate the vessel and reduce the absolute pressure and maintain it at the desired low pressure (0.1 to 0.95 bar) — thereby reducing the partial pressure of the desorbed CO2.

[0082] In accordance with at least one embodiment of the present disclosure, to maintain a high CO2 removal efficiency, the CO2 recovered during the sorbent regeneration may be reinserted into the process. For example, the recovered CO2 may be added to the stage-one sub-system feed. In some embodiments, the high-purity CO2 may be recovered directly from the sorbent regeneration. When higher vacuum (e.g., lower absolute pressure) is used in combination with a CO2 depleted purge gas (e.g., CO2 free flue gas, ambient air, and / or steam) the CO2 may be combined with the stage-one membrane permeate stream.

[0083] It should be noted that the stage-one subsystem, which may be a membrane subsystem itself, may be operated in two stages. The CO2 desorption product from the stage-one system may be sent to any of the first membrane feed (3 A of FIG. 3), the first membrane permeate, or the second membrane feed (3B). The destination of the CO2 desorption product may depend on the purge pressure used for desorbing CO2 from the solid-state sorbent bed.

[0084] In some embodiments, the desorption product from the solid-state sorbent subsystem may be sent to the first stage membrane permeate (e.g., between the first membrane unit and the second membrane unit, as seen at 3B in FIG. 3). This configuration may provide a high net plant efficiency. The net plant efficiency may be specific energy for CO2 capture and lower the lowest cost of CO2 capture. For example, this may be whencompared to DOE Rev.4 i.e., $38.0 per ton compared to $45.7 per ton for baseline Amine (Cansolv) based system on 2018 basis.

[0085] In some embodiments, the solid-state sorbent contactor is designed as a radial-type bed. This contactor design approach facilitates a low pressure-drop through the sorbent bed while also reducing the heigh of the sorbent contactor. Either Il-type (e.g., parallel inlet and outlet flow vectors) and Z-type (e.g., anti-parallel inlet and outlet flow vectors) beds may be utilized. In some embodiments, improved flow distribution and sorbent utilization may be obtained with a Il-type configuration.

[0086] The beds may be operated in either a centripetal manner (adsorption flow is radially inward) or a centrifugal manner (adsorption flow is radially outward). In both cases, the beds are designed to support flow in both directions as counter-current flow may be used when the sorbent material is regenerated. A series of valves and gas manifolds may be used to facilitate bed switching used in the complete sorbent cycle. In some embodiments, the cycle steps include adsorption, co-current blow-down, pressure equalization (between pairs of sorbent beds), counter-current blowdown, counter-current CO2 recovery / regeneration, and pressurization.

[0087] The techniques of the present disclosure may utilize multiple carbon separation technologies to improve the individual shortcomings of the associated technologies or techniques. In the case of membrane contactors, as the CO2 partial pressure is reduced, the driving force that causes CO2 to pass through the membrane (permeate) is also reduced. This can be overcome by applying stronger vacuum (lower pressure) on the permeate side of the membrane; however, this results in an additional energy penalty. Alternatively, the membrane area can be increased significantly, or the feed can be dramatically pressurized, but both of these solutions come with increased costs.

[0088] The hybrid system disclosed herein improves over the membrane-only operation by allowing the membrane to operate in its most efficient and economical mode, removing approximately half of the CO2 in the feed stream. Because a 50% removal efficiency is too low for most application, the second-stage sorbent contactor is used to remove the remaining CO2 from the retentate stream. Although the sorbent contactor’s performance is reduced when processing the C Ch-depleted retentate stream from the membrane, the dropin performance is minor — resulting in an overall efficiency improvement for the hybrid system (as compared to a stand-alone membrane system).

[0089] The hybrid CCS techniques disclosed herein and / or radial-bed sorbent contactor may be used to treat flue gas from a variety of point-source emitters. This includes power generation facilities that burn fossil fuels (coal or natural gas) or biomass feedstocks. In some embodiments, the hybrid approach may be used for other industrial sources such as steam methane reformers, cement kilns, steel refineries, and large-scale boilers or engines.

[0090] In some embodiments, the radial sorbent contactor improves over conventional axial sorbent contactors by reducing the pressure drop through the sorbent material. This allows the radial -bed contactor to operate at a lower inlet pressure which reduces the power required by the flue gas blower / compressor and further increases the overall CCS efficiency. By using this approach, the operating expense for a CCS system using radialbed contactors employed in a hybrid CCS will remove CCh at high efficiencies with relatively low operating cost. The radial-bed contactor has also been shown to reduce the potential for fines generation by reducing the amount of internal sorbent movement during bed cycling. This allows the sorbent material to have an improved lifetime — reducing the cost of sorbent relative to competitive contactor designs. It also reduces the need for downstream particulate removal from the clean (CCh-free) flue gas — reducing the capital system cost by allowing unnecessary equipment to be removed from the balance of plant while also further reducing the pressure required to overcome the pressure drop of post-CCS particulate filters.

[0091] The embodiments of the hybrid CCS have been primarily described with reference to wellbore drilling operations; the hybrid CCS described herein may be used in applications other than the drilling of a wellbore. In other embodiments, hybrid CCS according to the present disclosure may be used outside a wellbore or other downhole environment used for the exploration or production of natural resources. For instance, hybrid CCS of the present disclosure may be used in a borehole used for placement of utility lines. Accordingly, the terms “wellbore,” “borehole” and the like should not be interpreted to limit tools, systems, assemblies, or methods of the present disclosure to any particular industry, field, or environment.

[0092] One or more specific embodiments of the present disclosure are described herein. These described embodiments are examples of the presently disclosed techniques. Additionally, in an effort to provide a concise description of these embodiments, not all features of an actual embodiment may be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous embodiment-specific decisions will be made to achieve the developers’ specific goals, such as compliance with system-related and business-related constraints, which may vary from one embodiment to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

[0093] Additionally, it should be understood that references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. For example, any element described in relation to an embodiment herein may be combinable with any element of any other embodiment described herein. Numbers, percentages, ratios, or other values stated herein are intended to include that value, and also other values that are “about” or “approximately” the stated value, as would be appreciated by one of ordinary skill in the art encompassed by embodiments of the present disclosure. A stated value should therefore be interpreted broadly enough to encompass values that are at least close enough to the stated value to perform a desired function or achieve a desired result. The stated values include at least the variation to be expected in a suitable manufacturing or production process, and may include values that are within 5%, within 1%, within 0.1%, or within 0.01% of a stated value.

[0094] A person having ordinary skill in the art should realize in view of the present disclosure that equivalent constructions do not depart from the spirit and scope of the present disclosure, and that various changes, substitutions, and alterations may be made to embodiments disclosed herein without departing from the spirit and scope of the present disclosure. Equivalent constructions, including functional “means-plus-function” clauses are intended to cover the structures described herein as performing the recited function, including both structural equivalents that operate in the same manner, and equivalentstructures that provide the same function. It is the express intention of the applicant not to invoke means-plus-function or other functional claiming for any claim except for those in which the words ‘means for’ appear together with an associated function. Each addition, deletion, and modification to the embodiments that falls within the meaning and scope of the claims is to be embraced by the claims.

[0095] The terms “approximately,” “about,” and “substantially” as used herein represent an amount close to the stated amount that is within standard manufacturing or process tolerances, or which still performs a desired function or achieves a desired result. For example, the terms “approximately,” “about,” and “substantially” may refer to an amount that is within less than 5% of, within less than 1% of, within less than 0.1% of, and within less than 0.01% of a stated amount. Further, it should be understood that any directions or reference frames in the preceding description are merely relative directions or movements. For example, any references to “up” and “down” or “above” or “below” are merely descriptive of the relative position or movement of the related elements.

[0096] The present disclosure may be embodied in other specific forms without departing from its spirit or characteristics. The described embodiments are to be considered as illustrative and not restrictive. The scope of the disclosure is, therefore, indicated by the appended claims rather than by the foregoing description. Changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims

CLAIMSWhat is claimed is:

1. A carbon capture system comprising: a first subsystem configured to receive a gas flow comprising a first concentration of carbon dioxide, wherein the first subsystem is configured to separate the gas flow into a rich stream and a lean stream by a first carbon capture process, the rich stream including a second concentration of carbon dioxide greater than the first concentration, and the lean stream includes a third concentration of carbon dioxide less than the first concentration; and a second subsystem configured to receive the lean stream from the first subsystem, wherein the second subsystem includes: a carbon adsorption system to remove at least a portion of the carbon dioxide from the rich stream, resulting in a depleted stream; a flow separator to separate the depleted stream into a stack stream and a recycling stream; and a carbon desorption system to release the portion of the carbon dioxide into the recycling stream, wherein the recycling stream is directed to mix with at least one of the gas flow or the rich stream.

2. The carbon capture system of claim 1, wherein the first carbon capture process includes a membrane system.

3. The carbon capture system of claim 1, wherein the carbon adsorption system and the carbon desorption system include a sorbent material.

4. The carbon capture system of claim 3, wherein the carbon desorption system includes at least one of a vacuum pump, a steam purge, or a heater.

5. The carbon capture system of claim 1, wherein the recycling stream includes between 20% and 40% of a volumetric flow rate of the depleted stream.

6. The carbon capture system of claim 1, wherein the stack stream is directed to a stack.

7. The carbon capture system of claim 1, further comprising a third subsystem to receive the rich stream, and wherein the third subsystem is configured to separate the rich stream into a second rich stream and a second lean stream.

8. The carbon capture system of claim 7, wherein the recycling stream is mixed with the rich stream downstream of the first subsystem and upstream of the third subsystem.

9. The carbon capture system of claim 7, wherein the recycling stream includes at least a portion of the second lean stream.

10. The carbon capture system of claim 7, further comprising a cryogenic purification system configured to receive and purify the second rich stream, and wherein the recycling stream is directed to mix with the second rich stream downstream of the third subsystem and upstream of the cryogenic purification system.

11. A method for carbon capture, the method comprising: at a first carbon capture subsystem, separating a gas flow into a rich stream and a lean stream, the rich stream having a higher concentration of carbon dioxide than the lean stream; at a second carbon capture subsystem, adsorbing at least a portion of carbon dioxide in the lean stream, resulting in a depleted stream; at the second carbon capture subsystem, desorbing at least a part of the portion of the carbon dioxide into a recycling stream, the recycling stream diverted from the depleted stream; and recycling the recycling stream as an input to the first carbon capture subsystem or the rich stream.

12. The method of claim 11, wherein recycling the recycling stream includes mixing the recycling stream with the gas flow upstream of the first carbon capture subsystem.

13. The method of claim 11, wherein recycling the recycling stream includes mixing the recycling stream with the rich stream upstream of a third carbon capture subsystem.

14. The method of claim 11, wherein recycling the recycling stream includes mixing the recycling stream with an input to a cryogenic purification system.

15. A method for carbon capture, the method comprising: directing a gas stream through a first carbon capture system, the first carbon capture system separating the gas stream into a rich stream and a lean stream; directing the lean stream through a second carbon capture system, the second carbon capture system removing residual carbon dioxide from the lean stream resulting in a depleted stream; releasing at least part of the residual carbon dioxide from the second carbon capture system into a recycling stream, the recycling stream having a lower carbon dioxide concentration than the lean stream; and directing the recycling stream to at least one of the gas stream or the rich stream.

16. The method of claim 15, further comprising separating the depleted stream into a stack stream and the recycling stream.

17. The method of claim 15, wherein the second carbon capture system includes a sorbent material, and wherein releasing the part of the residual carbon dioxide includes releasing the part of the residual carbon dioxide from the sorbent material using at least one of a vacuum pump, a steam purge, or a heater.

18. The method of claim 15, wherein directing the gas stream through the first carbon capture system includes directing the gas flow through a membrane system.

19. The method of claim 15, wherein directing the recycling stream includes directing the recycling stream to the gas stream upstream of the first carbon capture system.

20. The method of claim 15, wherein directing the recycling stream includes directing the recycling stream to the rich stream downstream of the first carbon capture system.

Images