System and method for hydrogen sweeping of carbon dioxide-loaded sorbents

Abstract

A sorbent sweep method includes, after a sorption phase, directing hydrogen into a sorbent chamber housing a quantity of sorbent, resulting in a desorption flow exiting the sorbent chamber. The desorption flow includes an outlet hydrogen proportion and a desorbed carbon dioxide proportion. The method further includes separating the desorbed carbon dioxide proportion from the desorption flow and recovering the outlet hydrogen proportion to a hydrogen reservoir.

Description

DAIR-M00-PCTSYSTEM AND METHOD FOR HYDROGEN SWEEPING OF CARBON DIOXIDE-LOADED SORBENTSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This Application claims the benefit of U.S. Provisional Application No. 63 / 703,912 filed on 05-OCT-2024, which is incorporated in its entirety by this reference.TECHNICAL FIELD

[0002] This invention relates generally to the field of carbon dioxide capture (hereinafter “carbon capture”) and more specifically to a new and useful system and method for hydrogen sweeping of carbon dioxide-capturing sorbents in the field of carbon capture.BACKGROUND

[0003] Sorbent regeneration for carbon capture has been widely investigated as a means to enable the repeated use of solid sorbents for the removal of carbon dioxide from gas streams. Conventional regeneration processes typically rely on thermal treatment at elevated temperatures, often at or above 120 °C, to release adsorbed carbon dioxide efficiently and restore sorbent capacity. However, exposure of sorbents to such high temperatures frequently results in thermal degradation of the sorbent material, leading to a progressive loss of sorbent capacity over repeated cycles.

[0004] In addition to thermal degradation, oxidative degradation of sorbents presents a further challenge during conventional regeneration. The presence of oxygen, either as a component of the process gas or as a contaminant, can lead to the formation of free radicals that attack the sorbent structure. This free radical-driven damage accelerates the breakdown of sorbent materials, further reducing their effectiveness and operational lifetime. Existing regeneration methods have not adequately addressed the susceptibility of sorbents to oxidative degradation under typical process conditions.

[0005] Another mode of sorbent degradation arises from urea linkage formation, which can occur at regeneration temperatures of 80 °C or higher. The reaction between amine-functionalized sorbents and carbon dioxide at these temperatures can result in the formation of stable urea linkages, which are not readily reversible under standard regeneration conditions. The accumulation of urea species on the sorbent surface leads to a reduction in available amine sites and a corresponding decrease in sorbent capacity. The combined effects of thermal, oxidative, and chemical stresses during repeated purging cycles contribute to a rapidDAIR-M00-PCT overall loss of sorbent lifetime, with some systems exhibiting significant capacity loss in as little as one month of continuous operation. The inability of existing regeneration strategies to maintain sorbent performance over extended periods has limited the practical deployment of solid sorbent-based carbon capture technologies.BRIEF DESCRIPTION OF THE FIGURES

[0006] FIGURE 1 A is a flowchart representation of one variation of a method.

[0007] FIGURE IB is a flowchart representation of one variation of the method.

[0008] FIGURE 2 is a schematic representation of one variation of a system configured to execute the method.

[0009] FIGURE 3 A-C are flowchart representations of three timing variations of the method.

[0010] FIGURE 4 A and 4B are schematic representations of variations of the system configured to execute the method.DESCRIPTION OF THE EMBODIMENTS

[0011] The following description of embodiments of the invention is not intended to limit the invention to these embodiments but rather to enable a person skilled in the art to make and use this invention. Variations, configurations, implementations, example implementations, and examples described herein are optional and are not exclusive to the variations, configurations, implementations, example implementations, and examples they describe. The invention described herein can include any and all permutations of these variations, configurations, implementations, example implementations, and examples.

[0012] Generally, the term “can,” as utilized herein, indicates an action or attribute of the system, which may or may not be executed by or be applicable to the system depending on the implementation or embodiment of the system.

[0013] Generally, the term “include,” as utilized herein, can mean “comprise,” “consist of,” or “consist essentially of’ and is not restricted to any one of the above interpretations throughout.

[0014] Generally, the term “a set of,” as utilized herein, refers to one or more of the subject objects. Additionally, the terms “first,” “second,” “third,” etc., as utilized herein, do not imply an order but simply identify multiple instances of a step or component unless an order or series is otherwise implied.DAIR-M00-PCT

[0015] Generally, the terms “ratio” and “proportion” as utilized herein refer to molar ratios and molar proportions unless otherwise specified.

[0016] Generally, the adjective phrases “positive,” “positively charged,” and “cationic,” are interchangeable when utilized herein. Likewise, the adjective phrases “negative,” “negatively charged,” and “anionic” are also interchangeable when utilized.

[0017] Generally, the term “representative,” as utilized herein, indicates a central tendency statistic such as a mean or median of a particular data type over a short period of time suitable for use in the calculation of operational parameters.

[0018] Generally, the term “distribution,” as utilized herein, represents any characterization of data that approximates a true distribution of the data and is not intended to imply any degree of accuracy.

[0019] Generally, the term “defining,” as utilized herein, describes elements of a subject, is open-ended, and does not exclude additional, unrecited elements or method steps.

[0020] Generally, the term “water,” as utilized herein, describes any form of H2O including but not limited to liquid water, water vapor and steam unless specified otherwise.1. Sorbent Sweep Method

[0021] As shown in FIGURE 1A, the sorbent sweep method (hereinafter “the method SI 00”) includes: after a sorption phase, directing hydrogen 120 into a sorbent chamber 102 housing a quantity of sorbent 104 in Step SI 10, resulting in a desorption flow 124 exiting the sorbent chamber 102, the desorption flow 124 including an outlet hydrogen proportion 128 and a desorbed carbon dioxide 126 proportion; recovering the outlet hydrogen proportion 128 to a hydrogen 120 reservoir 114 in Step SI 12; and separating the desorbed carbon dioxide 126 proportion from the desorption flow 124 in Step SI 14.1.1 Sorbent Sweep Method Variation: Flush and Purge

[0022] As shown in FIGURE IB, in one variation, the method SI 00 includes two sweeps of hydrogen 120 through the sorbent chamber 102: first the blowdown phase, and second during the purging phase. In this variation, the method SI 00 includes sorption and blowdown phases that occur before purging the sorbent chamber 102. More specifically, the method SI 00 includes: during a sorption phase, directing an inlet flow 122 through a sorbent chamber 102 housing a quantity of sorbent 104, the inlet flow 122 comprising gaseous carbon dioxide in Step SI 02; and during a blowdown phase, terminating the inlet flow 122 through the sorbent chamber 102 inDAIR-M00-PCTStep S104, and flushing the sorbent chamber 102 with hydrogen 120 in Step S106. The method SI 00 further includes: during a purging phase, heating the sorbent chamber 102 to a target desorption temperature in Step SI 08, and purging the quantity of sorbent 104 by directing hydrogen 120 into the sorbent chamber 102 in Step SI 10, resulting in a desorption flow 124 comprising a desorbed carbon dioxide proportion 126 and an outlet hydrogen proportion 128; and during a recovery phase, separating the outlet hydrogen proportion 128 from the desorption flow 124 in Step SI 12, and separating the desorbed carbon dioxide 126 proportion from the desorption flow 124 in Step SI 14.2. Applications

[0023] Generally, the method SI 00 includes a process for purging carbon dioxide-loaded sorbents 104 (e.g., regenerating sorbent active sites) using hydrogen 120 under controlled thermal and atmospheric conditions. The method SI 00 is executed by a sorbent sweep system (hereinafter “the system 100”) characterized by a closed-loop architecture that includes a hydrogen 120 supply subsystem, a sorbent chamber 102, and a desorption gas treatment train 132. The method SI 00 executes steps including carbon dioxide adsorption, oxygen blowdown, temperature ramping, hydrogen purging, desorption gas conditioning, hydrogen-carbon-dioxide separation, and closed-loop hydrogen 120 recycling. The method SI 00 enables low-temperature, energy-efficient, and chemically selective regeneration of a wide range of sorbent materials, while preserving sorbent integrity and minimizing operational costs through high-efficiency hydrogen 120 recovery and reduced degradation rates.

[0024] The system 100 and method SI 00 address the problem of thermal degradation of sorbents 104 at purging temperatures at or above 100 °C, which leads to irreversible loss of sorbent capacity, by utilizing hydrogen 120 as the purging gas. Hydrogen 120 remains gaseous at these lower temperatures (than steam, for example), enabling continued desorption of carbon dioxide during sweeping at temperatures below 100 °C. Generally, the system 100 maintains the sorbent chamber temperature within a controlled window of approximately 60 to 90 °C. However, the system 100 can maintain sorbent chamber temperatures outside this range based on other design priorities (such as a design goal of maximizing desorption rate). By operating at these moderate temperatures, the system 100 avoids the high-temperature thresholds that induce sorbent volatilization, backbone scission, or pore collapse, thereby extending sorbent service life.

[0025] The method SI 00 further mitigates the problem of oxidative degradation of sorbents 104 caused by oxygen exposure during purges, which leads to free radical-driven damage and rapidDAIR-M00-PCT capacity loss. The system 100 employs a closed-loop piping architecture with gas-tight valving, ensuring that the sorbent chamber 102 is purged of oxygen (e.g., to below 0.1 mass percentage) prior to heating. Automated blowdown and exhaust composition monitoring, combined with in-situ oxygen sensors and control logic, prevent ingress of ambient air and enable safe operation with hydrogen. The exclusion of oxygen suppresses the formation of oxidative degradation products and preserves the chemical integrity of amine and other functional groups within the sorbent matrix.

[0026] Generally, the method SI 00 can execute the sweep and purging steps with any form of hydrogen 120 (e.g., gaseous, liquid, ion, radicals etc) as an inert fluid. Unlike nitrogen and other inert fluids, hydrogen 120 can be efficiently separated from carbon dioxide using pressure swing adsorption or membrane separation methods due to the molecular size difference between carbon dioxide (330 picometers) and hydrogen (289 picometers). Thus, using hydrogen 120 as an inert sweep gas results in less energy-intensive separation of the effluent and, therefore, less energy demand to isolate carbon dioxide.

[0027] The method SI 00 includes selectively separating and recycling hydrogen 120 using pressure swing adsorption (hereinafter “PSA”)and / or membrane separation. Thus, upon separation and recycling of hydrogen 120, the system can achieve high-purity carbon dioxide isolation (greater than 95 mass-percent purity, less than 50 parts-per-million hydrogen 120) and can recycle greater than 98 percent of the hydrogen 120. Additionally, hydrogen 120 is selected as the sweep gas for the method described herein as a result of the many useful products that can be derived from the effluent flow containing hydrogen 120. For example, the system can utilize a carbon dioxide, and hydrogen 120 mixture, with or without water, (e.g., effluent from the purging phase) for many applications like e-natural gas and e-fuel.

[0028] Finally, the method SI 00 addresses the high energy consumption (4 to 6 GJ / ton CO?) of conventional thermal or steam purging of solid sorbents 104. The system integrates low-grade heat sources, staged heat recovery from desorption gas condensation, and, in some implementations, selective combustion of hydrogen 120 during blowdown and reconditioning phases to achieve a reduction in purging energy.

[0029] Thus, the sorbent sweep method SI 00 can minimise sorbent degradation by reducing cumulative oxidative, thermal, and chemical stress during desorption. By preventing the degradation of the sorbent, the method SI 00 can extend sorbent operational lifetime from weeks to multiple years. Because sorbent-related costs can account for upwards of 60% of the total cost of existing carbon capture processes, the method SI 00 can vastly improve the economic viability of carbon capture at scale.DAIR-M00-PCT3. Sorbent Sweep System

[0030] As shown in FIGURE 2, the system 100 is configured to maintain the adsorption capacity of a carbon dioxide-loaded sorbent by introducing hydrogen 120 into a thermally controlled sorbent chamber 102, while simultaneously desorbing carbon dioxide from the sorbent. More specifically, the system 100 can include a hydrogen 120 delivery subsystem (e.g., a pump 136 configured to direct hydrogen 120 through a set of pipes and through the sorbent chamber), a sorbent chamber 102, and a desorption gas treatment train 132 that receives the desorption gas outlet from the sorbent chamber 102. The system 100 can be adapted for use with a range of sorbent types, including amine-functionalized solids, metal-organic frameworks, zeolites, or other chemisorptive or physisorptive materials. The system 100 can also include various dampers, valves, and blowers configured to transport various gases and fluids between components of the system 100. Furthermore, the system 100 can include a controller configured to electronically control various components of the system 100 to execute the method SI 00 based on instructions stored on a transient computer-readable medium.

[0031] The sorbent chamber 102 can include a pressure- and temperature-tolerant vessel configured to contain a quantity of sorbent 104 (e.g., solid or liquid sorbents 104). The chamber can be constructed to withstand internal pressures generated during the purging or desorption phase, and can be thermally insulated to maintain operational temperatures typically in the range of 50 to 120 °C. The chamber can incorporate internal flow distributors or baffles configured to promote uniform distribution of inlet gas (e.g., ambient air or process gas) and hydrogen 120 across the sorbent chambers 102. The vessel can include dedicated inlet and outlet ports for process gases, which may be equipped with electromechanical valves to control the sequence of adsorption, blowdown, purging, and / or reconditioning phases. The sorbent chamber 102 can be configured for various sorbent geometries, including, but not limited to, fixed-bed, moving-bed, or monolithic arrangements, and can accommodate a range of sorbent types, including, but not limited to, amine-functionalized solids, metal-organic frameworks, zeolites, or liquid sorbents 104. The sorbent chamber 102 can further include integrated temperature sensors, pressure transducers, and sampling ports to monitor process conditions and enable feedback control. The sorbent chamber 102 can also be constructed from materials compatible with exposure to ambient air and / or process gases, hydrogen 120, water vapor, and carbon dioxide, and can include corrosion-resistant linings or coatings as required by the selected sorbent. These features collectively address the need for robust containment, thermal management, and processDAIR-M00-PCT flexibility, thereby mitigating the risks of sorbent degradation and enabling efficient, repeatable cycles.

[0032] The hydrogen 120 delivery subsystem can be configured to store, condition, and deliver hydrogen 120 to the sorbent chamber 102 for the purpose of sweeping and / or purging a carbon dioxide-loaded sorbent and desorbing carbon dioxide from the sorbent. The hydrogen 120 delivery subsystem can be configured for operation with multiple forms of hydrogen 120, including, but not limited to, dry hydrogen gas, humidified hydrogen, ionized hydrogen 120, and hydrogen 120 mixtures in gaseous and / or liquid forms. The hydrogen 120 delivery subsystem can include storage vessels constructed of materials compatible with hydrogen 120, conditioning units (e.g., humidifiers or heaters to adjust the temperature and humidity of the hydrogen 120), and / or metering devices such as mass flow controllers or pressure regulators to maintain a controlled flow rate and pressure of hydrogen 120. The hydrogen 120 delivery subsystem can be configured to maintain a slight over-pressure relative to the sorbent chamber 102 to ensure unidirectional flow and to prevent ingress of ambient air, which could introduce oxygen and promote oxidative degradation of the sorbent. Safety features can include non-retum valves, flame arrestors, and gas detection sensors to prevent back-flow, ignition, or hazardous gas accumulation. The hydrogen 120 delivery subsystem can also incorporate automated control logic to adjust flow parameters based on the sweep protocol, sorbent type, or operational phase (e.g., sorption, blowdown, purge, or reconditioning). The hydrogen 120 delivery subsystem can be integrated with the downstream sorbent chamber 102 and desorption gas treatment train 132 to enable closed-loop operation and minimize hydrogen 120 consumption.

[0033] In one implementation, the desorption gas treatment train 132 includes a gas separation stage (e.g., a gas separator 108) and a hydrogen 120 recovery loop. For example, the desorption gas treatment train 132 directs the desorption gas mixture exiting the sorbent chamber 102, including hydrogen 120 and desorbed carbon dioxide 126, to a gas separation unit, such as a PSA unit or a membrane separator, which selectively isolates high-purity carbon dioxide from the desorption gas flow. The desorption gas treatment train 132 can be configured to separate and route hydrogen 120 to a hydrogen 120 reservoir 114 of the hydrogen 120 delivery subsystem for reuse in subsequent cycles of the method SI 00.4. Sorbent Sweep Method Overview

[0034] The sorbent sweep method SI 00 can simultaneously protect the adsorption capacity of a carbon dioxide-loaded sorbent and desorb carbon dioxide from the sorbent by executing a sequence of operations that employ hydrogen 120 that “swings” the concentration of carbonDAIR-M00-PCT dioxide from concentrations found in ambient air to near zero, thereby liberating carbon dioxide from the sorbent with the addition of moderate heat. More specifically, as shown in FIGURES 3A-C, the method SI 00 can include a sorption phase, a blowdown phase, a purging phase, a recovery phase, and / or a reconditioning phase in various implementations. The timing of the various phases shown in FIGURES 3A-3C is described in further detail below. The method S100 can utilize hydrogen 120, which is introduced into a sorbent chamber 102 under controlled thermal conditions, during the blowdown and purging phases. After the sorption phase, during which carbon dioxide is adsorbed into a quantity of sorbent 104 within the sorbent chamber 102, the method S100 can initiate the blowdown phase by terminating the inlet flow 122 (e.g., including inlet ambient air or process gas) to the sorbent chamber 102 and flushing the chamber with hydrogen 120. During the blowdown phase, the system 100 displaces residual oxygen, thereby minimizing oxidative degradation of the sorbent. Once the chamber atmosphere is turned over, the method SI 00 can direct hydrogen 120 through the sorbent chamber 102 at a temperature typically ranging from 50°C to 120°C, with preferred operation between 60°C and 90°C during the purging phase. Thus, the system 100 causes desorption of carbon dioxide and water vapor from the sorbent while avoiding excessive thermal stress that could degrade the sorbent material. In the recovery phase, the system 100 can then separate hydrogen 120 and the carbon dioxide from the effluent gas mixture or desorption flow 124. By separating carbon dioxide and hydrogen 120 (e.g., via PSA, membrane separation, or any other separation method), the system 100 can isolate high-purity carbon dioxide and recover hydrogen 120 for recycling.

[0035] The method SI 00 is applicable to a range of sorbent types, including amine-functionalized solids, metal-organic frameworks, zeolites, and other nitrogen-containing or non-amine sorbents 104. By enabling sorbent purging at lower energy input compared to conventional thermal or inert gas purging approaches, the method SI 00 reduces the risk of thermal and oxidative degradation, and facilitates closed-loop operation with minimal hydrogen 120 loss. Thus, the method SI 00 addresses the technical challenges of high energy consumption, rapid sorbent degradation, and limited sorbent lifetime in carbon capture applications.5. Sorption Phase

[0036] Generally, during a sorption phase, the method SI 00 includes directing an inlet flow 122 (e.g., air) through a sorbent chamber 102 housing a quantity of sorbents 104 in Step SI 02, the inlet flow 122 including gaseous carbon dioxide. As a result of Step SI 02, the quantity of sorbents 104 binds a proportion of the carbon dioxide within the inlet flow 122.DAIR-M00-PCT

[0037] During the sorption phase, the system 100 can further monitor a concentration of carbon dioxide exiting the sorbent chamber 102 and, in response to a concentration of carbon dioxide in the outlet flow from the sorbent chamber 102 exceeding a threshold carbon dioxide concentration, terminate the inlet flow 122 in Step S104. Generally, the system 100 is configured to monitor the concentration of carbon dioxide in the gas stream exiting the sorbent chamber 102. For example, the system 100 can employ an inline non-dispersive infrared (NDIR) analyzer or equivalent gas sensor positioned at the outlet of the sorbent chamber 102 to provide real-time measurement of carbon dioxide concentration with a typical update interval ranging from 1 to 5 seconds. This continuous monitoring enables the system 100 to track the progression of the adsorption front through the sorbent chamber 102.

[0038] As the sorbent approaches saturation, the desorbed carbon dioxide proportion 126 concentration begins to rise, indicating breakthrough. The system 100 executes control logic configured to compare the measured desorbed carbon dioxide 126 proportion concentration to a predetermined threshold, which may be set as a fraction of the inlet carbon dioxide concentration or as an absolute value, depending on the application and sorbent type. When the desorbed carbon dioxide proportion 126 concentration exceeds this threshold, the system 100 can automatically terminate the inlet flow 122 to the sorbent chamber 102 in Step S104, thereby concluding the sorption phase. The use of real-time breakthrough monitoring and automated flow termination ensures that the sorbent is utilized to near its maximum working capacity without risking over-saturation, which could lead to excessive purging times or incomplete desorption in subsequent cycles.6. Blowdown Phase

[0039] As shown in FIGURE 4 A, the method SI 00 includes a blowdown phase during which the system 100 terminates the inlet flow 122 in Step S104 and directs a flow of hydrogen 120 into the sorbent chamber 102 in Step SI 06 to flush remaining inlet gas, which may include oxygen, out of the sorbent chamber 102. More specifically, the method SI 00 includes: terminating the inlet flow 122 through the sorbent chamber 102; and flushing the sorbent chamber 102 with hydrogen 120. In particular, flushing the sorbent chamber 102 with hydrogen 120 can include: directing a flow of hydrogen 120 through the sorbent chamber housing, resulting in a blowdown outlet flow exiting the sorbent chamber 102, the blowdown outlet flow including an inlet gas proportion and hydrogen 120 proportion; monitoring a concentration of the inlet gas proportion of the outlet flow; and in response to the concentration of the inlet gas proportion less than a blowdown air concentration, terminating the flow of hydrogen 120DAIR-M00-PCT through the sorbent chamber 102. Thus, in implementations including the blowdown phase, the system 100 transitions the atmosphere of the sorbent chamber 102 from including a combination of various inlet gases to an atmosphere including hydrogen 120 and small amounts of desorbed carbon dioxide 126 and water vapor. Thus, during the blowdown phase, the system 100 flushes a mixture of hydrogen 120 and the inlet gas from the sorbent chamber 102.

[0040] During Step SI 06, the system 100 can introduce hydrogen 120 into the sorbent chamber 102 at a controlled flow rate, thereby displacing residual inlet gas from the chamber. The system 100 can monitor the blowdown outlet gas composition using an in-line oxygen sensor or gas analyzer, and the introduction of hydrogen 120 can continue until the oxygen concentration in the blowdown outlet gas falls below a predetermined threshold, such as less than 1% by mass or volume. The step can be performed at ambient or elevated temperature and pressure, with hydrogen flow rate, total blowdown volume, and endpoint oxygen concentration adjusted based on the sorbent chamber 102 volume, ambient oxygen content of the inlet gas, and target process safety margins. By reducing the concentration of oxygen within the sorbent chamber 102 prior to the purging phase, the blowdown phase directly reduces the risk of oxidative degradation of the sorbent, thereby reducing sorbent lifetime loss due to oxidation.

[0041] In one implementation, flushing the sorbent chamber 102 with hydrogen 120 during Step S106 includes: directing the flow of hydrogen 120 through the sorbent chamber 102 housing resulting in a blowdown outlet flow exiting the sorbent chamber 102, whereby the blowdown outlet flow includes an inlet gas proportion and hydrogen 120 proportion; monitoring a concentration of the inlet gas proportion of the outlet flow; and in response to the concentration of the inlet gas proportion less than a blowdown air concentration, terminating the flow of hydrogen 120 through the sorbent chamber 102.

[0042] In one implementation, the system 100 can define two separate exhaust routes from the sorbent chamber 102: a blowdown exhaust route and a purging exhaust route. The system 100 can close a damper or valve controlling flow to the purging exhaust route during the blowdown phase, while opening a damper or valve controlling flow to the blowdown exhaust route during the blowdown phase.

[0043] As shown in FIGURE 4B, in implementations in which gaseous hydrogen 120 is used, the system 100 can direct the blowdown outlet flow toward a combustion chamber to initiate combustion of hydrogen 120 in the blowdown outlet flow by utilizing the oxygen present in the blowdown outlet flow in the combustion reaction. In this implementation, the system 100 can direct energy generated by the combustion of hydrogen 120 in the blowdown outlet flow toward heating the sorbent chamber 102 in preparation for the purging phase. More specifically, theDAIR-M00-PCT system 100 can, during the blowdown phase, flush the sorbent chamber 102 with gaseous hydrogen 120, resulting in a blowdown outlet flow exiting the sorbent chamber 102, whereby the blowdown outlet flow includes an outlet air proportion and hydrogen 120 proportion; and combusting the blowdown outlet flow. The system can then, during the purging phase, heat the sorbent chamber 102 via energy generated from combusting the blowdown outlet flow.

[0044] Alternatively, the system 100 can direct energy generated by the combustion of hydrogen 120 in the blowdown outlet flow toward other Steps of the method SI 00, such as to drive pressure-based separation of carbon dioxide from hydrogen 120. Thus, the system 100 can recover energy from hydrogen 120 that would otherwise be expelled from the system 100 during the blowdown phase.7. Purging Phase

[0045] Generally, the purging phase of the method S100 includes: applying thermal energy to the sorbent chamber 102 to elevate the temperature of the sorbent chamber 102 to a target range suitable for desorption of carbon dioxide and other volatiles in Step SI 08; and purging carbon dioxide from the sorbents 104 in Step SI 10. More specifically, the system 100 can direct hydrogen 120 into a sorbent chamber 102 housing a quantity of sorbent 104, resulting in a desorption flow 124 exiting the sorbent chamber 102, the desorption flow 124 including an outlet hydrogen proportion 128 and a desorbed carbon dioxide proportion 126. In particular, the system 100 can also include heating the sorbent chamber 102 to a target desorption temperature; and purging the quantity of sorbent 104 by directing hydrogen 120 into the sorbent chamber 102, resulting in a desorption flow 124 comprising a desorbed carbon dioxide 126 proportion and an outlet hydrogen proportion 128. Thus, the purging phase can include heating the sorbent chamber 102 to release carbon dioxide from the sorbent, while simultaneously sweeping the chamber with hydrogen 120 to maintain a low concentration of carbon dioxide in the atmosphere of the sorbent chamber 102.7, 1 Sorbent Chamber Heating

[0046] Generally, the method SI 00 can include applying thermal energy (e.g., via a heating unit 116) to the sorbent chamber 102, in Step SI 08, to elevate a temperature within the sorbent chamber 102 to a target range suitable for desorption of carbon dioxide and other volatiles, as well as purging carbon dioxide from the sorbents 104. More specifically, the system 100 can, after the sorption phase and / or the blowdown phase, heat the sorbent chamber 102 to a target desorption temperature. The system 100 can achieve the temperature ramp by indirect heating methods, such as preheating hydrogen 120 to a target preheat temperature at or above the targetDAIR-M00-PCT desorption temperature, circulating a heat transfer fluid through a jacket or heat exchanger surrounding the sorbent chamber 102, direct electrical heating using embedded resistive elements, utilizing heat recovered from combustion of the blowdown stream, or via any other suitable heating method. As shown in FIGURE 4B, the system 100 can include a combustion path connecting the outlet of the sorbent chamber 102 to the heating unit 116, thereby enabling the heating unit 116 to heat the sorbent chamber 102 by combusting the blowdown outlet flow (e.g., including hydrogen 120 and oxygen). In one implementation, during the purging phase, heating the sorbent chamber to the target desorption temperature includes: preheating hydrogen to a target preheat temperature at or above the target desorption temperature; and directing the hydrogen, at the target preheat temperature, into the sorbent chamber.

[0047] The target temperature for this step can typically range from approximately 60 °C to 120°C, with the specific target temperature selected based on the thermal stability of the sorbent material and the desired desorption kinetics. The system 100 can maintain the temperature for a duration sufficient to enable sufficient desorption of carbon dioxide (e.g., greater than 95% desorption) and to facilitate the action of hydrogen 120, while avoiding temperatures that would induce thermal degradation of amine functionalities or other sorbent reactive groups.

[0048] In some implementations, the temperature ramp can be coordinated with the introduction of hydrogen 120 in Step SI 10 to prevent the formation of sorbent degradation compounds, such as urea, carbamate, or bicarbonate species. The heating profile, including ramp rate and hold time, can be adjusted according to the sorbent type, chamber geometry, and process integration requirements. By enabling thermal control and integration with hydrogen 120 introduction, the system 100 addresses the technical challenge of minimizing thermal and oxidative degradation of the sorbent while achieving efficient carbon dioxide desorption at lower energy input than conventional methods.7,2 Purging with Hydrogen

[0049] Generally, the purging phase further includes purging the sorbent chamber 102 with a flow of hydrogen 120 in Step SI 10. More specifically, during Step SI 10, the system 100 purges the quantity of sorbent 104 by directing hydrogen 120 into the sorbent chamber 102, resulting in a desorption flow 124 including: a desorbed carbon dioxide 126 proportion and an outlet hydrogen proportion 128. The system 100 can select the superficial velocity of the hydrogen 120 flow to ensure sufficient contact with the sorbent material, thereby enabling both physical desorption of carbon dioxide and water vapor and chemical purging of the quantity of sorbent 104.DAIR-M00-PCT

[0050] Generally, the desorption flow 124 exiting the sorbent chamber 102 during Step S 110 can include a mixed gas stream containing hydrogen 120, desorbed carbon dioxide 126, and / or water vapor, with the composition varying according to the form of hydrogen 120 used, sorbent type, and operating conditions. The step can be performed in either continuous or batch mode, and the hydrogen 120 flow can be recycled after downstream removal of carbon dioxide and water.

[0051] In one implementation, the system 100 can utilize a wet gas purging phase including steam as well as hydrogen 120 in the purging gas mixture. More specifically, the system 100 can include, after the sorption phase, directing hydrogen 120 and an inlet water proportion into the sorbent chamber 102 housing the quantity of the sorbent, resulting in the desorption flow 124 exiting the sorbent chamber 102. In this implementation, the desorption flow 124 includes the outlet hydrogen proportion 128, the desorbed carbon dioxide 126 proportion, and an outlet water proportion.8. Recovery Phase

[0052] Generally, the recovery phase of the method SI 00 includes a set of conditioning steps during which the desorption flow 124 exits the sorbent chamber 102 after purging, and is separated into constituents by the desorption gas treatment train 132 (e.g., including a gas separator 108). More specifically, the system 100: separates the outlet hydrogen proportion 128 from the desorption flow 124 in Step SI 12 and separates the desorbed carbon dioxide 126 proportion from the desorption flow 124 in Step SI 14. Additionally or alternatively, the recovery phase can include conditioning of the desorption flow 124, such as condensing of water vapor and removal of particulates. In various implementations, the system 100 can execute steps SI 12 and SI 14 in a batch or continuous process. Additionally, the system 100 can adjust the specific temperature and residence time based on the composition of the effluent and the requirements for downstream gas separation or purification. Thus, the system 100 can recover a large proportion of hydrogen 120 for use in future sorption-desorption cycles. In one implementation, in Step SI 14, the desorbed carbon dioxide proportion 126 can be separated from the desorption flow 124 and be directed into a carbon dioxide reservoir 138 for storage.

[0053] Generally, as shown in FIGURES 3 A, 3B, and 3C, Steps SI 12 and SI 14 can occur concurrently or in any order. For example, as shown in FIGURE 3A, the outlet hydrogen proportion 128 may first be separated from the desorption flow 124 and then the carbon dioxide proportion 126. However, Step SI 14 may occur before Step SI 12 as shown in FIGURE 3C.

[0054] In one implementation, the desorption flow 124 conditioning can be performed by passing the desorption flow 124 (e.g., including hydrogen 120, carbon dioxide, water vapor,DAIR-M00-PCT and / or any entrained solids) through a heat exchanger, fin-fan cooler, or knock-out drum. More specifically, the system 100 can condense the outlet water proportion of the desorption flow 124 into liquid water, and recover the liquid water into a water reservoir 112. In particular, the system 100 can lower the temperature of the desorption flow 124 to a value at or below the dew point of water vapor present in the desorption flow 124, typically in the range of 5 to 40 °C, depending on design parameters and ambient conditions. As the temperature decreases, water vapor condenses into liquid water, which can be separated from the gas phase by gravity, centrifugal, or coalescing mechanisms within a knock-out drum or similar separator. The condensed water can be collected in a reservoir for reuse in subsequent process steps, such as humidifying hydrogen 120 or for other process needs. The system 100 can also remove fine particulates or aerosols by employing demisters, mesh pads, or cyclonic separators integrated into the condensation apparatus.

[0055] In one implementation, as shown in FIGURES 4A and 4B, the system 100 can include a gas separation unit 108, such as PSA or membrane separation, to optimize process efficiency and minimize energy consumption. By condensing water vapor from the desorption flow 124, the system 100 shrinks the gas volume, protects downstream separation media from moisture, and enables closed-loop water recovery for re-humidification of the hydrogen 120 sweep. The collection of high-purity condensate for reuse in humidifying the hydrogen 120 gas or other plant operations reduces replacement water demand and eliminates the need for external water-treatment infrastructure. These features support the closed-loop, resource-efficient operation of the sorbent sweep method.

[0056] Generally, the method S100 includes Step SI 12 during which hydrogen 120 is separated from the desorption flow 124. In one implementation, shown in FIGURE 5, the system 100 can separate hydrogen 120 from the desorption flow 124 via PSA or membrane separation prior to storage or reuse. The system 100 can recover hydrogen 120 in Step SI 12 by separating hydrogen 120 from the desorption flow 124 utilizing PSA. More specifically, the system 100 can separate the desorbed carbon dioxide 126 proportion from the desorption flow 124 by separating the desorbed carbon dioxide 126 proportion from the hydrogen 120 proportion via PSA. In this implementation, the desorption gas treatment train 132 can include gas separation units 108.

[0057] In one implementation, utilizing PSA to execute Step S112, the system 100 can pressurise, meter, or otherwise condition the recycled hydrogen 120 to achieve a target delivery pressure and flow rate suitable for reintroduction into the sorbent chamber 102 in subsequent blowdown and / or purging cycles. In one implementation, the system 100 can employ compressors, pumps, or flow controllers to maintain a closed-loop operation, thereby reducingDAIR-M00-PCT the requirement for fresh hydrogen input. For any hydrogen species, the system 100 can further monitor the purity and composition of the recycled hydrogen 120 during Step SI 12 to ensure compatibility with the sorbent material and to prevent accumulation of contaminants. The process can be operated in a batch or continuous mode, and the recycled hydrogen 120 can be blended with make-up hydrogen 120 as needed to maintain process stability and efficiency. By enabling the bulk of hydrogen 120 to be continuously recovered and reused, the system 100 maintains closed-loop operation, which minimizes fresh gas consumption, reduces operating cost, and lowers the logistical footprint relative to open-loop purging methods.

[0058] The gas separation unit 108 can utilize multiple membrane separation approaches tailored to the desorption flow composition. For example, the gas separation unit 108 can execute Steps SI 12 and SI 14 via: polymeric hollow-fiber or spiral -wound modules that preferentially permeate carbon dioxide and retain hydrogen; inorganic molecular-sieve membranes (e.g., zeolite or carbon) that exploit sorption-diffusion selectivity for carbon dioxide; MOF-based membranes in plate-and-frame or hollow-fiber formats with moisture-tolerant coatings; Pd-alloy metallic membranes configured to purify hydrogen and carbon dioxide to protect the alloy; and / or mixed-matrix membranes incorporating zeolite, MOF, or carbon fillers in polymeric films arranged in one or more stages. The method SI 00 can incorporate any of these implementations to achieve carbon dioxide and hydrogen recoveries. In high-pressure membrane-separation implementations, the gas separation unit 108 can accept the desorption flow directly from the sorbent chamber and return a hydrogen stream to the hydrogen recycling loop without additional compression. In vacuum-assisted sweep implementations, the gas separation unit 108 can maintain a low-permeate pressure with a corrosion-resistant vacuum train and a cold trap while integrating standard safeguards such as pressure relief, oxygen analyzers, and automated isolation valves to protect the oxygen-free sorbent chamber and maintain a purged low-oxygen chamber atmosphere.9. Reconditioning Phase

[0059] In one implementation, the method SI 00 includes a reconditioning phase, during which the system 100 resets a post-purging sorbent chamber 102 in preparation for a subsequent sorption phase in Step SI 16. More specifically, during the reconditioning phase, the system 100 can direct the inlet flow 122 through the sorbent chamber 102, resulting in a reconditioning outlet flow exiting the sorbent chamber 102. The reconditioning outlet flow can include an outlet air proportion and a hydrogen proportion 120. Thus, by directing inlet air into the sorbent chamber 102, the system 100 increases the concentration of carbon dioxide to at least ambientDAIR-M00-PCT atmospheric proportions, thereby enabling continued sorption of carbon dioxide by the quantity of sorbent 104.

[0060] In one implementation, the system 100 can combust the reconditioning outlet flow by redirecting the reconditioning outlet flow toward the combustion chamber. In these implementations, the system 100 can heat the sorbent chamber 102 during a subsequent desorption phase via energy generated from combusting the reconditioning outlet flow. Alternatively, the system 100 can utilize the recovered heat energy for any other purpose described above with respect to the method SI 00.10. Desorption Product Tuning

[0061] In one implementation, the method SI 00 can include tuning the ratio of constituents in the desorption flow to satisfy a target product ratio, such as to generate a target gas mixture from the desorption process. More specifically, directing hydrogen into the sorbent chamber during Step SI 10 can include directing a quantity of hydrogen into the sorbent chamber, the quantity of hydrogen based on a target product ratio of hydrogen and carbon dioxide. As a result, the desorption flow can include approximately the target product ratio of hydrogen and carbon dioxide. In one implementation, the target product ratio is a molar ratio of carbon dioxide and hydrogen, and, therefore, the quantity of hydrogen is a molar quantity of hydrogen based on the target molar ratio of carbon dioxide and hydrogen in the desorption flow. For example, the target product ratio (or the target molar ratio) can define a target ratio of three parts hydrogen to one part carbon dioxide. Therefore, the system 100 can execute the method to generate a desorption flow characterized by the target product ratio.

[0062] In another implementation, the quantity of hydrogen is selected based on a predicted quantity of desorbed carbon dioxide. More specifically, directing the quantity of hydrogen into the sorbent chamber, the quantity of hydrogen based on the target product ratio of hydrogen and carbon dioxide can include: predicting a quantity of desorbed carbon dioxide; and calculating the quantity of hydrogen based on the quantity of desorbed carbon dioxide and the target product ratio. For example, the quantity of desorbed carbon dioxide can be predicted (e.g., calculated) based on: an amount of carbon dioxide in the inlet flow (e.g., a partial pressure of carbon dioxide in the inlet flow); and amount of inlet flow allowed into the sorbent chamber (e.g., volumetric flow rate integrated over the sorption phase); the quantity of sorbents within the sorbent chamber (e.g., the carbon dioxide capture capacity the quantity of sorbents); and a desorption efficiency (e.g., a proportion of carbon dioxide desorbed). Therefore, the amount of hydrogen used toDAIR-M00-PCT sweep the sorbent chamber can be based on the predicted amount of carbon dioxide in the desorption flow.

[0063] In yet another implementation, the quantity of hydrogen is selected based on an amount of desorbed carbon dioxide detected in the desorption flow by a gas analyzer unit arranged at a desorption outlet of the sorbent chamber. More specifically, the system can include a gas analyzer configured to: sense an amount of carbon dioxide present in a volume of gas exiting the sorbent chamber; and output a signal to a controller of the system 100 indicating the amount of carbon dioxide. In response to the signal indicating the amount of carbon dioxide, the controller of the system can modulate operation of the hydrogen delivery subsystem to direct the quantity of hydrogen into the sorbent chamber, wherein the quantity of hydrogen fulfills the target product ratio based on the gas analyzer signal. Therefore, the system can select and adjust a flow rate of hydrogen directed into the sorbent chamber in near real-time in response to a gas analyzer signal to fulfill the target product ratio.11. Additional Considerations

[0064] The systems and methods described herein can be embodied and / or implemented at least in part as a machine configured to receive a computer-readable medium storing computer-readable instructions. The instructions can be executed by computer-executable components integrated with the application, applet, host, server, network, website, communication service, communication interface, hardware / firmware / software elements of a user computer or mobile device, wristband, smartphone, or any suitable combination thereof. Other systems and methods of the embodiment can be embodied and / or implemented at least in part as a machine configured to receive a computer-readable medium storing computer-readable instructions. The instructions can be executed by computer-executable components integrated by computer-executable components integrated with apparatuses and networks of the type described above. The computer-readable medium can be stored on any suitable computer-readable media such as RAMs, ROMs, flash memory, EEPROMs, optical devices (CD or DVD), hard drives, floppy drives, or any suitable device. The computer-executable component can be a processor but any suitable dedicated hardware device can (alternatively or additionally) execute the instructions.

[0065] As a person skilled in the art will recognize from the previous detailed description and from the figures and claims, modifications and changes can be made to the embodiments of the invention without departing from the scope of this invention as defined in the following claims.

Claims

DAIR-M00-PCTCLAIMSWe Claim:

1. A method comprising:• after a sorption phase, directing hydrogen into a sorbent chamber housing a quantity of sorbent, resulting in a desorption flow exiting the sorbent chamber, the desorption flow comprising: o an outlet hydrogen proportion; and o a desorbed carbon dioxide proportion;• separating the desorbed carbon dioxide proportion from the desorption flow; and• recovering the outlet hydrogen proportion to a hydrogen reservoir.

2. The method of Claim 1, further comprising, after the sorption phase, heating the sorbent chamber to a target desorption temperature between 60 °C and 110 °C.

3. The method of Claim 1, wherein:• after the sorption phase, directing hydrogen into the sorbent chamber housing the quantity of the sorbent, further comprises directing a water proportion into the sorbent chamber; and• the desorption flow exiting the sorbent chamber further comprises an outlet water proportion.

4. The method of Claim 3, wherein separating the desorbed carbon dioxide proportion from the desorption flow comprises:• condensing the outlet water proportion of the desorption flow into liquid water; and• recovering the liquid water in a water reservoir.

5. The method of Claim 3, wherein separating the desorbed carbon dioxide proportion from the desorption flow comprises:• directing the desorption flow through a heat exchanger to separate the water proportion of the desorption flow from the carbon dioxide proportion; and• recovering the water proportion from the heat exchanger into the water reservoir.DAIR-M00-PCT6. The method of Claim 1, wherein separating the desorbed carbon dioxide proportion from the desorption flow comprises separating the desorbed carbon dioxide proportion via pressure swing adsorption.

7. The method of Claim 1, wherein separating the desorbed carbon dioxide proportion from the desorption flow comprises separating the desorbed carbon dioxide proportion via membrane separation.

8. A method comprising:• during a sorption phase: o directing an inlet flow through a sorbent chamber housing a quantity of sorbent, the inlet flow comprising gaseous carbon dioxide;• during a blowdown phase: o terminating the inlet flow through the sorbent chamber; and o flushing the sorbent chamber with hydrogen;• during a purging phase: o heating the sorbent chamber to a target desorption temperature; and o purging the quantity of sorbent by directing hydrogen into the sorbent chamber, resulting in a desorption flow comprising a desorbed carbon dioxide proportion and an outlet hydrogen proportion;• during a recovery phase: o separating the outlet hydrogen proportion from the desorption flow; and o separating the desorbed carbon dioxide proportion from the desorption flow.

9. The method of Claim 8, wherein heating the sorbent chamber to the target desorption temperature comprises heating the sorbent chamber to the target desorption temperature between 60 °C and 110 °C.

10. The method of Claim 8, wherein flushing the sorbent chamber with hydrogen during the blowdown phase comprises:• directing a flow of hydrogen through the sorbent chamber housing, resulting in a blowdown outlet flow exiting the sorbent chamber, the blowdown outlet flow comprising: o an inlet gas proportion; andDAIR-MOO-PCT o a hydrogen proportion;• monitoring a concentration of the inlet gas proportion of the outlet flow; and• in response to detecting the concentration of the inlet gas proportion less than a blowdown air concentration, terminating the flow of hydrogen through the sorbent chamber.

11. The method of Claim 8, wherein:• flushing the sorbent chamber with hydrogen during the blowdown phase comprises directing a flow of hydrogen through the sorbent chamber housing, resulting in a blowdown outlet flow exiting the sorbent chamber, the blowdown outlet flow comprising: o an inlet gas proportion; and o a hydrogen proportion; and• purging the quantity of sorbent by directing hydrogen into the sorbent chamber comprises purging the quantity of sorbents by directing the hydrogen proportion of the blowdown outlet flow into the sorbent chamber.

12. The method of Claim 8, wherein purging the sorbent chamber with hydrogen during the purging phase comprises:• monitoring a concentration of desorbed carbon dioxide in the desorption flow; and• in response to the concentration of the desorbed carbon dioxide less than a purging concentration threshold, terminating the flow of hydrogen through the sorbent chamber.

13. The method of Claim 8:• further comprising, during the recovery phase: o directing hydrogen and an inlet water proportion into the sorbent chamber housing the quantity of the sorbent, resulting in the desorption flow exiting the sorbent chamber, the desorption flow comprising:■ the outlet hydrogen proportion;■ the desorbed carbon dioxide proportion; and■ an outlet water proportion; o condensing the outlet water proportion of the desorption flow into liquid water; and o recovering the liquid water into a water reservoir.DAIR-M00-PCT14. The method of Claim 8, wherein, during the recovery phase, separating the outlet hydrogen proportion from the desorption flow comprises separating the outlet hydrogen proportion from the desorbed carbon dioxide proportion via pressure swing adsorption.

15. The method of Claim 8, wherein, during the recovery phase, separating the outlet hydrogen proportion from the desorption flow comprises separating the outlet hydrogen proportion from the desorbed carbon dioxide proportion via membrane separation.

16. The method of Claim 8:• wherein, during the blowdown phase, flushing the sorbent chamber with gaseous hydrogen results in a blowdown outlet flow exiting the sorbent chamber, the blowdown outlet flow comprising: o an outlet air proportion; and o a hydrogen proportion; and• further comprising combusting the blowdown outlet flow.

17. The method of Claim 16, further comprising, during the purging phase, heating the sorbent chamber via energy generated from combusting the blowdown outlet flow.

18. The method of Claim 8, further comprising:• during a reconditioning phase, directing the inlet flow through the sorbent chamber, resulting in a reconditioning outlet flow exiting the sorbent chamber, the reconditioning outlet flow comprising: o an outlet air proportion; and o a hydrogen proportion; and• combusting the reconditioning outlet flow.

19. The method of Claim 18, wherein, during the purging phase, heating the sorbent chamber comprises heating the sorbent chamber via energy generated from combusting the reconditioning outlet flow.

20. The method of Claim 8, wherein, during the purging phase, heating the sorbent chamber to the target desorption temperature comprises:DAIR-MOO-PCT• preheating hydrogen to a target preheat temperature at or above the target desorption temperature; and• directing the hydrogen, at the target preheat temperature, into the sorbent chamber.

21. A method comprising, after a sorption phase, directing hydrogen into a sorbent chamber housing a quantity of sorbent, resulting in a desorption flow exiting the sorbent chamber, the desorption flow comprising:• an outlet hydrogen proportion; and• a desorbed carbon dioxide proportion.

22. The method of Claim 21 :• wherein directing hydrogen into the sorbent chamber comprises directing a quantity of hydrogen into the sorbent chamber, the quantity of hydrogen based on a target product ratio of hydrogen and carbon dioxide; and• wherein the desorption flow comprises approximately the target product ratio of hydrogen and carbon dioxide.

23. The method of Claim 22, wherein the quantity of hydrogen is a molar quantity of hydrogen based on target molar ratio carbon dioxide and hydrogen in the desorption flow.

24. The method of Claim 22, wherein directing the quantity of hydrogen into the sorbent chamber, the quantity of hydrogen based on the target product ratio of hydrogen and carbon dioxide comprises:• predicting a quantity of desorbed carbon dioxide; and• calculating the quantity of hydrogen based on the quantity of desorbed carbon dioxide and the target product ratio.

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