Sorptive co 2 gas separation process with moisture swing regeneration

Abstract

An improved sorptive gas separation process for a sorptive separator with a sorbent comprising amines, the process employing moisture swing at elevated temperatures, where the sorbents maintain sorptive capacity at the elevated temperatures.

Description

[0001] SORPTIVE CO2GAS SEPARATION PROCESS WITH MOISTURE SWING REGENERATION

[0002] PRIOR APPLICATIONS

[0003] The present invention is related to previously filed PCT International Patent Application No. PCT / IB2023 / 061810, filed November 22, 2023, and published as International Publication Number WO 2024 / 110902 A1 , titled “SOLID PRIMARY AMINE AND AMIDINE-BASED MATERIALS FOR ADSORPTIVE GAS SEPARATION OF CO2, WITH IMPROVED AIR, WATER AND TEMPERATURE TOLERANCE”, the contents of which are herein incorporated by reference in their entirety.

[0004] FIELD

[0005] The present technology relates generally to sorptive gas separation processes using partial pressure swing interacting with a solid sorbent to trigger sorption or desorption of a target component from a multi-component gas stream. In particular, it relates to separation of carbon dioxide from a flue gas using a stream primarily comprising steam to recover a concentrated stream of carbon dioxide from a solid sorbent.

[0006] BACKGROUND

[0007] Sorptive gas separation processes using solid sorbents can comprise three main process steps and are carried out in, for example, a sorptive separator which can also be referred to as a sorbent separator or a sorptive separation machine.

[0008] The three main process steps can be a feed or a sorbing step for separating a target gas component from a feed stream; a desorbing, regeneration, or steam step for collecting the target gas component; and a conditioning step with the use of air or nitrogen (N2) for drying and / or cooling of the sorbent. Additional reflux steps where one or more product or effluent streams from the sorptive separator can be recovered and admitted as a portion of a feed or an influent stream into the sorptive separator can be used to achieve the desired specifications of one or more product streams. The reflux step is also dependent on the sorbent’s selectivity and affinity for the target component.

[0009] Desirably, the temperature of each stream admitted into a sorptive separator can be adjusted by either heating or cooling the stream. Control and adjustments to a pressure of each stream admitted into a sorptive separator can also be desired. During a feed step, the water content of the feed stream can also be controlled by controlling a pressure and / or temperature of the feed stream, resulting in a decrease or increase in the dew point of water in the feed stream.

[0010] For rapid cycle sorptive gas separation applications, for example, when a complete process cycle occurs in less than about two minutes, employing moisture swing mechanisms relies on the supply of at least a portion of heat to the sorbent via the sorption or condensation of water on the sorbent. For most sorbents, leaving water in and / or on the sorbent can: impede and reduce the sorption capacity of the sorbent, decrease the efficiency, and / or increase the cycle time.

[0011] To increase the efficiency of a rapid cycle sorptive gas separation process or cycle it can be desirable to reduce the number of steps in the sorptive gas separation process in order to reduce the overall cycle time and potentially to increase the overall capacity of a given sorptive separator. An example of a rapid cycle sorptive gas separation process and system are disclosed in International Publication Number WO 2022 / 238934 A2.

[0012] Conventional sorbents have substantially reduced sorptive capacity at temperatures greater than about 100°C, especially with the presence of water, making conventional sorbents unsuitable for the inventive methods disclosed herein.

[0013] SUMMARY

[0014] In a broad aspect, a sorptive gas separation process for separating a first component from a multi-component gas stream comprises: a) introducing the multicomponent gas stream as at least a portion of a feed stream with a first component, into a first sorption zone of a sorptive separator with a sorbent, sorbing the first component with the sorbent in the first sorption zone, producing a first product stream depleted in the first component relative to the feed stream, and recovering the first product stream from the first sorption zone, and b) introducing a first regeneration stream comprising steam into a first regeneration zone of the sorptive separator, desorbing the first component from the sorbent in the first regeneration zone, producing a second product stream enriched in the first component relative to the feed stream and recovering the second product stream from the first regeneration zone, wherein the sorbent has a sorption capacity for the first component at Ts-reg. of at least 20% of the sorption capacity the first component at Ts-sorp.

[0015] BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Fig. 1a is a perspective view illustrating a sorptive separator configured with a contactor rotating through two zones;

[0017] Fig. 1 b is a diagram illustrating a modeled concentration profile of carbon dioxide, nitrogen, and water through a sorptive separator as shown in Fig. 1a;

[0018] Fig. 1c is a diagram illustrating a modeled concentration profiles of carbon dioxide, nitrogen, and water through a sorptive separator similar to that shown in Fig.

[0019] 1a, wherein a feed stream and regeneration stream are configured to flow in a co-flow direction relative to each other;

[0020] Fig. 2 is a schematic diagram of sorptive separator with a contactor moving through a first sorption zone for performing a sorption step and a first desorption zone for performing a regeneration step;

[0021] Fig. 3 is a schematic diagram as shown in Fig. 2 with the addition of a second regeneration zone for performing a reflux step;

[0022] Fig. 4 is a schematic diagram as shown in Fig. 3 with the addition of a second sorption zone for performing a first recycle step;

[0023] Fig. 5 is a schematic diagram as shown in Fig. 4 with the addition of a third sorption zone for performing a second recycle step;

[0024] Fig. 6 is a schematic diagram similar to Fig. 5, wherein at least a portion of first product stream is blended with a portion of feed stream and introduced into second sorption zone 15 according to an embodiment of the invention; Fig. 7 is a schematic diagram similar to Fig. 6, wherein at least a portion of first product stream is blended with a portion of feed stream and introduced into third sorption zone 16 according to an embodiment of the invention;

[0025] Fig. 8a is a graph of modeled temperature plots along various axial locations of a contactor during a conventional three-step process, wherein the x-axis is time and the y-axis is temperature;

[0026] Fig. 8b is a graph of modeled temperature plots along various axial locations of a contactor during a two-step process according to an embodiment of the invention, wherein the x-axis is time and the y-axis is temperature;

[0027] Fig. 9a is a cross-sectional drawing of a sorbent or a composite material 400 configured in a random mixture of a first material and a second material;

[0028] Fig. 9b is a cross-sectional drawing of a sorbent or a composite material configured with a core shown as a first material and a shell shown as a second material;

[0029] Fig. 9c is a cross-sectional drawing of a sorbent or a composite material configured with an inner layer or sheet shown as a first material and a plurality of outer layers shown as a second material; wherein arrows represents the direction of flow of the gas streams in relation to the sorbent;

[0030] Fig 10a is a graph illustrating product (CO2) recovery along the y-axis and product (CO2) purity along the x-axis, comparing the conventional three-step sorptive gas separation process to the two-step sorptive gas separation process;

[0031] Fig 10b is a graph illustrating steam consumption during regeneration or a steam ratio along the y-axis and a feed stream (CO2) composition along the x-axis, comparing the conventional three-step sorptive gas separation process to the two-step sorptive gas separation process; and

[0032] Fig. 11 is a schematic diagram of a sorptive gas separation system using a two-step process in a first stage sorptive separator and a second stage sorptive separator according to an embodiment of the invention. DETAILED DESCRIPTION

[0033] Definitions

[0034] Sorption front: a feed stream flows through a sorptive contactor and contacts the sorbent, sorption of a first component occurs. The sorption front is a boundary where the concentration of the first component in the gas phase decreases (as a result of sorption of the first component on the sorbent) relative to the concentration of the first component in the feed stream, for example, a boundary where the concentration of the first component decreases to less than about 25% of the concentration of the first component in the feed stream. The sorption front moves from the feed stream inlet toward the first product stream outlet of a contactor as a result of sorption of the first component over a period of time during a sorption step.

[0035] Desorption front: as a desorption or regeneration stream is admitted and flows through a sorptive contactor in contact with the sorbent, desorption of a first component can occur. The desorption front is a boundary where the concentration of the first component in the gas phase increases (as a result of desorption of the first component from the sorbent) relative to the concentration of the first component in the feed stream, for example, a boundary where the concentration of the first component increases to greater than about 75% of the concentration of the first component in the feed stream. The desorption front moves from the desorption or regeneration stream inlet toward the second product stream outlet of a contactor as a result of desorption of the first component or over a period of time during a regeneration step.

[0036] Evaporator: device for converting a liquid stream into a gas stream. An evaporator can vaporize a component of a liquid stream or vaporize one or more components from a plurality of fluid streams, for example, from a gas stream mixed with a liquid stream, a plurality of liquid streams, a fluid stream with gas and liquid, or a liquid stream mixed with a fluid stream comprising a gas and a liquid.

[0037] DCC: Direct Contact Cooler is a device where a gas stream is directed to contact a liquid stream for transferring heat from the gas stream to the liquid stream. A DCC can also function as a vaporizer by increasing a moisture content while cooling the gas stream. Dry basis: a concentration in a fluid stream once condensable components, in particular the water vapor, are removed.

[0038] Recycled stream: at least a fraction of a product or effluent stream of a sorptive process and sorptive separator which is reintroduced as at least a portion of an influent stream into the sorptive process and sorptive separator. In some situations a recycled stream can be substantially the same composition or temperature as a product or effluent stream, however, the pressure of the recycled stream can be increased to allow reintroduction of the recycled stream into an influent stream of higher pressure.

[0039] Stream conditioning or pre-conditioning: adjusting pressure, temperature, moisture content or concentration of a minor component of a stream without significantly changing the relative concentration of the major component of the stream.

[0040] Contactor: a device comprising at least one solid sorbent on and / or in a substantially continuous structure and desirably substantially continuous flow channels between an inlet and an outlet of the structure which is also arranged to enable fast exchange or kinetics between the solid and gas phases. The contactor can comprise a plurality of sorbent sheets forming a monolith, an extruded monolith, or packed solid particles. A contactor can also be referred to as a bed, for example, a sorptive bed or a packed bed. There can be one or more contactors in a sorptive separator. Typically, a contactor is undergoing or performing a single step of a sorptive separation process at a given time. A sorptive separator with a plurality of contactors can optionally be configured to undergo or perform multiple steps of a sorptive separation process with the plurality of contactors which are fluidly separate from each other at a given time.

[0041] Sorbing or Sorption step: a process step carried out in a discreet period or event within a sorptive separation process for separating by sorbing a first component from the feed stream while forming a first product stream depleted in the first component relative to the feed stream.

[0042] Regenerating or Regeneration step: a process step carried out in a discreet period or event within a sorptive separation process for desorbing or removing the first component from the sorbent while forming a second product stream enriched in the first component relative to the feed stream. Conditioning or Condition step: a process step carried out in a discreet period or event with a sorptive separation process for removing a desired component on or in the sorbent while decreasing the sorbent temperature and forming a third product stream. In embodiments, the process can be configured and controlled to add or sorb a component on or in the sorbent while increasing the sorbent temperature and forming a third product stream. In embodiments, the process can be configured and controlled such that a difference between the conditioning step and the regeneration step is that the conditioning step does not produce a third product stream enriched in the first component relative to the feed stream. In the case of carbon capture applications, the first component can be CO2.

[0043] Ts-sorp.: an average sorbent temperature at the end of a sorption step in a sorptive separation process. This temperature can be controlled by controlling the regeneration stream temperature and composition, as well as the selection of the sorbent material and its heat capacity. Ts-sorp. can be measured, modeled, and included in the control logic of the process.

[0044] Ts-reg.: an average sorbent temperature at the end of the regeneration step in a sorptive separation process. This temperature can be controlled by controlling the partial pressure and quantity of the regeneration stream, for example, a stream comprising steam, as well as the selection of the sorbent material and its heat capacity. Ts-reg. can be measured, modeled, and included in the control logic of the process and in particular to desirably reduce the quantity of the regeneration stream or steam used.

[0045] Ts-swing: an absolute value of the difference between Ts-sorp. and Ts-reg.

[0046] Description

[0047] In embodiments, a simplified two-step sorptive gas separation process was developed for use with a specific type of solid sorbent which advantageously eliminates the requirement or desire for a third or condition step while enabling a high recovery rate of a target or first component from a feed stream.

[0048] In conventional sorptive gas separation processes, a condition step provides time and a sink for a sorbent to cool and dry between the end of a regeneration step using steam and the beginning of a sorbing step. The condition step re-establishes the sorbents capacity to sorb the first component to a level sufficient or desired for the subsequent sorption step.

[0049] Applicant has found that for sorbents with a significantly greater sorption capacity for the first component at high temperatures, for example, above about 100°C, an increased capture efficiency, and / or cycle capacity can be obtained while cooling the regenerated sorbent. When switching from a regeneration stream comprising about 100% steam during a regeneration step to a feed stream comprising less than about 6% steam during a subsequent sorption step, the driving force to remove water sorbed from a sorbent is considerable for structured sorbents with high kinetic rates of exchange which exhibit temperature decrease rates of about 10°C per second or greater as a cooling front propagates from a feed stream inlet to a first product stream outlet of a sorptive separator.

[0050] Developing a desorption front for water that is propagating in the direction of the flow of a feed stream faster than a sorption saturation front by the first component present in a drying stream, for example, a feed stream, enables the use of a portion of the contactor for sorption of the first component under favorable conditions while downstream portions are still drying and cooling. The portions that have not dried or cooled are not yet ready to effectively capture the first component, for example, CO2, from the feed stream.

[0051] Prior developments of sorbents were aimed at reducing the energy cost for desorption and maximizing sorption capacity per cycle. However, these high- performance solid sorbents could not perform well under a two-step process as their sorption efficiency and capacity of the first component at higher temperatures, for example, above about 80°C to 100°C were too low. Amine-based sorbents can enable sorption of the first component at higher temperatures as they exhibit a higher fraction of high heat of sorption sites, however, they do increase the energy cost of sorbent regeneration.

[0052] It is also important to note that embodiments of the present invention does not work well for sorbents substantially comprising non-aminated Metal-Organic Framework (MOF) materials because of the strong water-CO interaction on these sorbents which require a low threshold of dryness to be attained before starting a sorbing step. However, a mixture of amine-based high temperature sorption materials combined with a Metal-Organic Framework sorbent can allow the use of these materials or sorbents in a novel two-step process.

[0053] Embodiments of the present invention tailors or engineers a sorptive gas separation process to a sorbent’s properties for a target or first component, for example, CO2, and water sorption capacity to enable simultaneous sorption of the first component and drying to take place upon switching from a regeneration stream using a steam or a diluted steam stream to a feed stream, for example, a combustion gas stream, a flue gas stream, a process gas stream, an air stream, or a biogas stream.

[0054] A practical demonstration is outlined below for a solid amine-based sorbent predominantly containing primary amines.

[0055] This technology is particularly relevant when utilized in conjunction with the use of structured sorbent contactors whose sorption and desorption kinetics allow for high recovery efficiency of the first component, for example, CO2. In structured sorbent contactors, a small fraction of the volume of the sorbent contactor is transitioning from regeneration to saturation at any given time while sorption and desorption fronts move across or through the contactor in the direction of flow of the feed stream.

[0056] With reference to Fig. 1 a, a sorption step occurs in a sorption zone, while a regeneration step occurs in a regeneration zone where the sorption step and regeneration step are substantially equal in duration. During the sorption step, a feed stream 3, for example, a flue gas stream, is admitted into sorptive separator 1 where a target or first component, for example, carbon dioxide, is sorbed on and / or in a sorbent and separated from feed stream 3. A first product stream 4 depleted in the target component is recovered from contactor 2 and sorptive separator 1 . During the regeneration step, a regeneration stream 5, for example, a stream comprising steam, is admitted into sorptive separator 1 which desorbs the target or first component from the sorbent, and a second product stream 6 enriched in the target component is recovered from contactor 2 and sorptive separator 1 . As shown, Fig. 1a is a perspective view of a sorptive separator 1 having a contactor 2 comprising a solid sorbent, where contactor 2 moves or rotates and cycles through a sorption zone and a regeneration zone. During a sorbing step, a feed stream 3 can be introduced into the sorption zone of sorptive separator 1 to contact the sorbent on and / or in contactor 2 in the sorption zone. A first component in feed stream 3 can be sorbed on and / or in the sorbent, producing a first product stream 4 depleted in the first component relative to feed stream 3. First product stream 4 is recovered from a portion of contactor 2 in the sorption zone and sorptive separator 1 . During a regeneration step, a regeneration stream 5 is introduced into the regeneration zone of sorptive separator 1 to contact the sorbent on and / or in contactor 2 in the regeneration zone. The first component sorbed on the sorbent is desorbed producing a second product stream 6 enriched in the first component relative to feed stream 3. Second product stream 6 is recovered from a portion of contactor 2 in the regeneration zone and sorptive separator 1 .

[0057] Figs. 1 b and 1c illustrate concentration profiles for CO2, N2 and H2O along a length of a contactor (y-axis) versus time (along the x-axis) in a contactor during a first adsorption or sorbing step, a steam or regeneration step, and a portion of a second adsorption or sorbing step, where pink represents carbon dioxide, blue represents nitrogen, and grey represents water. The feed stream was representative of a flue or combustion gas stream. Fig. 1 b shows the concentration profiles where the feed stream and the regeneration or steam stream were introduced into the contactor in a counter-flow direction in relation to each other, where the sorption step and regeneration step are substantially equal in duration and the feed stream and regeneration stream are configured in a counter-flow direction relative to each other. The y-axis is representative of the length of the contactor as a feed or regeneration stream flows through the contactor, while the x-axis is representative of time. The colour pink illustrates carbon dioxide, the colour blue illustrates nitrogen, and the colour grey illustrates water.

[0058] Fig. 1c shows the concentration profiles where the feed stream and the regeneration or steam stream are introduced into the contactor in a co-flow direction. The y-axis is representative of the length of the contactor as a feed or regeneration stream flows through the contactor, while the x-axis is representative of time. The colour pink illustrates carbon dioxide, the colour blue illustrates nitrogen, and the colour grey illustrates water. In Fig. 1 b during a sorbing step and the introduction of the feed stream into the contactor, the sorption band for CO2 can be observed to increase from the inlet of the feed stream to the outlet of the first product stream over time as the sorbent becomes saturated with the sorbate. During a subsequent regeneration step, as a regeneration or steam stream is introduced into the contactor in a counter-flow direction, the CO2 is pushed towards the outlet side relative to the direction of flow of the steam stream leaving the sorbent saturated with moisture towards the end of the regeneration step. During the next subsequent sorbing step (only a portion shown in Fig. 1 b), a band comprising substantially nitrogen between the CO2 saturation front and the moisture desorption front expands over time.

[0059] A difference in propagation speed can be attributed to a greater concentration swing for moisture from about 100% steam in a regeneration stream during a regeneration step to less than 5% steam in a feed stream during a sorbing step relative to a concentration swing for CO2 in the feed stream and the regeneration stream while the relative capacity of the sorbent for moisture and CO2 are about the same order of magnitude. Figs. 1a and 1 b were obtained using a model simulating an amine-based sorbent contactor with a contactor temperature changing in the range of 50°C to 100°C as a function of sorption and desorption of CO2 and water. Temperature profiles for the modelling are shown in Figs. 8a and 8b.

[0060] In an embodiment, a sorptive gas separation process for separating a first component from a multi-component gas stream, for example, a combustion gas stream, a flue gas stream, a process gas stream, an air stream, or a biogas stream, for use as a feed stream, comprises a sorption step during which the sorbent on and / or in a contactor sorbs the first component, for example, CO2 and desorbs water or steam forming a stream depleted in the first component and enriched in steam relative to the feed stream where the axial loading of the first component or CO2 and steam in the contactor in the direction of flow of the feed stream is characterized by a drying propagating front shifted to a downstream axial position from the first component or CO2 sorption saturation front during the majority of the sorbing step.

[0061] In a further embodiment, the sorptive gas separation process enables greater than 80% capture or recovery of the first component or CO2 in the sorption step with the sorption step completed when the first component or CO2 saturation front reaches near or substantially the outlet of the contactor.

[0062] In an embodiment, the sorptive gas separation process can comprise four streams, a feed stream comprising the target or first component, for example, CO2, to be separated from the feed stream, a regeneration stream formed substantially from steam, a first product stream containing a fraction of the feed stream that is not sorbed and a second product stream containing an increased concentration of the first component or CO2 relative to the feed stream where greater than 80% of the first component or CO2 in the feed stream is transferred into the second product stream and the first component or CO2 concentration of the second product stream is at least 90% on a dry basis.

[0063] In an embodiment, the sorptive gas separation process can comprise four streams, a feed stream comprising the first component or CO2 to be separated from the feed stream, a regeneration stream formed substantially from steam, a first product stream containing a fraction of the feed stream that is not sorbed and a second product stream containing an increased concentration of the first component or CO2 relative to the feed stream, the Ts-swing upon switching of the feed stream and the regeneration stream, and / or the regeneration stream to the feed stream is equal to or greater than about 30°C with the regeneration stream formed substantially of steam where the sorbent material in contact with the feed stream and the regeneration stream has a first component or CO2 sorption capacity at Ts-reg. that is equal to or greater than about 20% of its sorption capacity for the first component at Ts-sorp.

[0064] Typically, Ts-sorp is in the range of 50°C to 80°C for CO2 capture from a flue gas with an amine-based sorbent whereas Ts-reg. is in the range of 90°C to 120°C. However, different conditions can be applied for different types of sorbents.

[0065] In a further embodiment, the sorptive gas separation process can be performed by a plurality of contactors comprising solid sorbents and gas flow channels, the plurality of contactors are moved through different zones cyclically where the fluidic connections to inlet and outlet streams to the zones are substantially stationary.

[0066] In a further embodiment, the sorptive gas separation process can be performed by a contactor comprising solid sorbents and gas flow channels, the contactor moves through different zones cyclically where the fluidic connections to inlet and outlet streams to the zones are substantially stationary.

[0067] In a further embodiment, the sorptive gas separation process can be performed by a contactor or a plurality of contactors comprising solid sorbents and gas flow channels being exposed cyclically to the feed stream and regeneration stream through opening and closing of valves fluidically connected to a vessel or enclosure and to the inlet and outlet fluid connections of a sorptive separator where the contactor or plurality of contactors and fluid connections for the various influent and effluent streams are substantially stationary.

[0068] In embodiments, a condition step typically employing a conditioning stream with a low concentration of CO2 and steam is not used. Instead, the feed stream can be utilized for the functions of cooling, removing steam, and sorbing the first component or CO2, and can be utilized simultaneously in different zones. The different functions of cooling, removing steam, and sorbing can occur at different axial positions within a contactor as a feed stream flows through the contactor.

[0069] Embodiments can include one or more of: recycling at least a portion of a reflux stream into the feed stream; recycling at least a portion of a first recycle stream into a second regeneration stream; recycling at least a portion of a second recycle stream into a portion of the feed stream, and recycling at least a portion of the first product stream into a portion of the feed stream.

[0070] Where a pressure of a recycle or reflux stream is lower than the pressure of stream into which it is blended with, for example a portion of the feed stream or the second regeneration stream, a means of mechanically increasing the pressure of the recycle or reflux stream can be used, for example, a fan, a blower, or other suitable means, can compress the stream, or an ejector can pull the stream in by reducing the kinetic energy of the stream that it is blended into.

[0071] Fig. 2 is a schematic diagram of a sorptive separator illustrating a contactor 10 of the sorptive separator with a sorbent (not shown) which moves and at least periodically cycles through various zones as shown by the dashed arrow during the sorptive gas separation process. Alternatively, a plurality of contactors can move and cycle through various zones, or one or more contactors can be stationary while the influent streams and effluent streams to each zone can be switched to simulate a moving contactor. The sorbent has a sorption capacity for CO2 at Ts-reg. of at least 20% of the sorption capacity for the first component, for example, CO2, at Ts-sorp.

[0072] As shown in Fig. 2, contactor 10 can have two zones, a first sorption zone 12 and a first regeneration zone 13. In a sorption step, a multi-component gas stream, for example, a combustion gas stream, a flue gas stream, a process gas stream, an air stream, or a biogas stream is used as at least a portion of a feed stream 101 which is introduced into first sorption zone 12 of the sorptive separator and / or contactor 10. As the feed stream contacts the sorbent in first sorption zone 12, the first component sorbs on and / or in the sorbent while the remaining non-sorbed components of feed stream 101 form a first product stream 202 depleted in the first component relative to feed stream 101 . First product stream 202 is recovered from first sorption zone 12 of the contactor and / or sorptive separator. In a regeneration step, a first regeneration stream 120 comprising substantially steam is introduced into a first regeneration zone 13 of the sorptive separator and / or contactor 10. As regeneration stream 120 contacts the sorbent, the moisture and / or heat desorbs the first component from the sorbent, producing a second product stream 220 enriched in the first component relative to feed stream 101 . Second product stream 220 is recovered from first regeneration zone 13 of contactor 10 and / or the sorptive separator. Additional first sorption zones and / or first regeneration zones can be employed in contactor 10. In an alternative embodiment, a sorptive separator can be configured having a plurality of separate contactors which cycle through different zones, either by moving the plurality of separate contactors through each zone, or switching or moving the flow of the influent streams to and effluent streams from the plurality of contactors which are substantially stationary.

[0073] Fig. 3 is a schematic diagram of the sorptive separator as shown in Fig. 2 with the addition of a second regeneration zone 14 for use during a reflux step of the sorptive gas separation process. A second regeneration stream 110 formed substantially from steam is introduced into the second regeneration zone 14 of contactor 10 and / or the sorptive separator, desorbing the first component from the sorbent, and producing a reflux stream 210 enriched in the first component relative to feed stream 101. The reflux stream 210 is recovered from the second regeneration zone 14 of contactor 10 and / or the sorptive separator. At least a portion of reflux stream 210 is blended into feed stream 101 for introducing into the first sorption zone 12 of contactor 10 and / or the sorptive separator. Additional second regeneration zones can be employed in contactor 10.

[0074] Fig. 4 is a schematic diagram of the sorptive separator as shown in Fig. 3 with the addition of a second sorption zone 15 for use during a first recycle step of the sorptive gas separation process. A portion of feed stream 101 is introduced into second sorption zone 15 of the sorptive separator and / or contactor 10 where the first component is sorbed on and / or in the sorbent in second sorption zone 15, producing a first recycle stream 201 depleted in the first component relative to feed stream 101 . First recycle stream 201 is recovered from second sorption zone 15 of contactor 10 and / or the sorptive separator and blended into second regeneration stream 110 for introducing into second regeneration zone 14 of contactor 10 and / or the sorptive separator. Alternatively, first recycle stream 201 is blended into the first regeneration stream 120 for introducing into first regeneration zone 13, or first recycle stream 201 is blended into the first regeneration stream 120 (not shown in Fig. 4) for introducing into first regeneration zone 13 and blended into second regeneration stream 110 for introducing into second regeneration zone 14. Additional second sorption zones can be employed in contactor 10.

[0075] Fig. 5 is a schematic diagram of the sorptive separator as shown in Fig. 4 with the addition of a third sorption zone 16 for use during a second recycle step of the sorptive gas separation process. A portion of feed stream 101 is introduced into third sorption zone 16 of the sorptive separator and / or contactor 10 where the first component is sorbed on and / or in and water is desorbed from the sorbent in third sorption zone 16, producing a second recycle stream 200 depleted in the first component and / or enriched in water relative to feed stream 101 . Second recycle stream 200 is recovered from third sorption zone 16 of contactor 10 and / or the sorptive separator and blended into a portion of feed stream 101 for introducing into second sorption zone 15 of contactor 10 and / or the sorptive separator. Additional third sorption zones can be employed in contactor 10. Fig. 6 is a schematic diagram of the sorptive separator similar to Fig. 5, however a portion of the first product stream 202 is recovered, recycled, and blended with a portion of feed stream 101 for introducing into the third sorption zone 16. Additional first and / or third sorption zones can be employed in contactor 10.

[0076] Fig. 7 is a schematic diagram of the sorptive separator similar to Fig. 6, however at least a portion of the first product stream 202 is recovered, recycled, and blended with a portion of feed stream 101 for introducing into the second sorption zone 15. Additional first and / or second sorption zones can be employed in contactor 10.

[0077] In an embodiment, a sorptive gas separation process for separating a first component from a multi-component gas stream, the process comprising the following steps:

[0078] (a) introducing the multi-component gas stream as at least a portion of a feed stream comprising a first component, for example, CO2 and a second component, for example, nitrogen, into a first sorption zone of a contactor and / or a sorptive separator, sorbing the first component with a sorbent on and / or in a portion of the contactor in the first sorption zone of the contactor and / or the sorptive separator, producing a first product stream depleted in the first component relative to the feed stream, and recovering the first product stream from the first sorption zone of the contactor and / or the sorptive separator, and

[0079] (b) introducing a first regeneration stream comprising substantially steam into a first regeneration zone of the contactor and / or the sorptive separator, desorbing the first component from the sorbent on and / or in a portion of the contactor in the first regeneration zone of the contactor and / or the sorptive separator, and producing a second product stream enriched in the first component relative to the feed stream and recovering the second product stream from the first regeneration zone of the contactor and / or the sorptive separator, wherein the sorbent has a sorption capacity for the first component or CO2 at Ts-reg. of at least 20% of the sorption capacity for the first component or CO2 at Ts- sorp.

[0080] In further embodiments of the sorptive gas separation process, the process can include one or more of: steps (a) and (b) are sequential; at least periodically repeating steps (a) and (b) sequentially; in step (a), desorbing water from the sorbent; in step (a), the first product stream is enriched in water relative to the feed stream; in step (a), recovering water from the first product stream; at the end of step (a), terminating the introducing of the feed stream into the first sorption zone; at the end of step (b) terminating the introducing of the first regeneration stream into the first regeneration zone; in step (a), the sorbing of the first component on the sorbent occurs when a temperature of the sorbent is at a sorbent temperature of equal to or greater than about 90°C, or equal to or greater than about 100°C; in step (a), the sorbing of the first component on the sorbent occurs when a pressure in the sorptive separator or at the sorbent is in a pressure range of 0.8 to 1 .2 bar, or 0.9 to 1 .1 bar; in step (a), a temperature of the sorbent decreases from the start of step (a) relative to the end of step (a); switching between at least one of step (a) to step (b), and step (b) to step (a), when a Ts-swing is equal to or greater than about 30°C; the sorbent is a resin sorbent with amines, an amine sorbent; the sorbent is an amine sorbent with amine groups comprising at least one of linear and cyclic primary amines, secondary amines, and a mixture of linear and cyclic amines; the linear amine n= 0 or greater and less than 12, n= 0 to 12, or preferably n= 2 or 3, A is at least one of oxygen, nitrogen, sulfur, -CH=CH-, -C=C-, -C=O, -SO2- or any combination thereof; the cyclic amine i t least one of oxygen, nitrogen, sulfur, -CH=CH-, -C=C-, -C=O, -SO2- or any combination thereof; the sorbent is an amine sorbent with a basic function which optionally includes amidine, guanidine groups or other organic bases; the sorbent comprise nitrogen with a nitrogen weight percent of equal to or greater than about 6%, equal to or greater than 7%, or equal to or greater than 8%; the sorbent has a sorption capacity for CO2 at Ts- reg. of at least 20% of the sorption capacity for CO2 at Ts-sorp; the multi-component gas stream is, for example, a combustion gas stream, a flue gas stream, a process gas stream, an air stream, a biogas stream, or combinations thereof; the first component is carbon dioxide; the sorbent is a solid, and the sorbent is a sorbent disclosed in International Publication Number WO 2024 / 110902.

[0081] In further embodiments of the sorptive gas separation process, the process includes:

[0082] • prior to step (b), a step (b1 ) introducing a second regeneration stream comprising water in the form of steam into a second regeneration zone of the contactor and / or the sorptive separator, desorbing the first component from the sorbent, and producing a reflux stream enriched in the first component relative to the feed stream and recovering the reflux stream enriched in the first component relative to the feed stream from the second regeneration zone of the contactor and / or the sorptive separator, and

[0083] • blending at least a portion of the reflux stream into at least a portion of the feed stream for introducing into at least one of the first sorption zone or a third sorption zone of the contactor and / or the sorptive separator.

[0084] In aspects of the embodiment step (b1 ), the sorptive gas separation process includes one or more of: directing the first regeneration stream for use as the second regeneration stream; the second regeneration stream differs from first regeneration stream in at least one of, a concentration or a vapor pressure of steam, pressure, temperature, flow rate, and velocity; and introducing of the second regeneration stream and producing of the reflux stream in a plurality of second regeneration zones of the contactor and / or the sorptive separator.

[0085] Step (b1 ) can enhance the purity of the second product stream at the cost of increasing the energy intensity of the sorptive gas separation process as the net yield of the process per sorbent volume is reduced which leads to an increase in steam usage per volume of CO2 recovered, i.e., the steam ratio.

[0086] In further embodiments of the sorptive gas separation process, the process includes:

[0087] • prior to step (a), a step (a1 ) introducing a portion of the feed stream into a second sorption zone of the contactor and / or the sorptive separator, sorbing the first component with the sorbent in the second sorption zone of sorptive separator of the contactor and / or the sorptive separator, producing a first recycle stream depleted in the first component and / or enriched in water relative to the feed stream, recovering the first recycle stream from the second sorption zone of the contactor and / or the sorptive separator, and

[0088] • blending the first recycle stream into at least one of the first regeneration stream for introducing into the first regeneration zone of the contactor and / or the sorptive separator, the second regeneration stream for introducing into the second regeneration zone of the contactor and / or the sorptive separator, and the at least a portion of the feed stream for introducing into the first sorption zone of the contactor and / or the sorptive separator.

[0089] In aspects of the embodiment step (a1 ), the process includes one or more of: blending the first recycle stream into the second regeneration stream for introducing into a plurality of second regeneration zones of the contactor and / or the sorptive separator; adding and / or introducing water in a liquid phase to the portion of the feed stream for introduction into the second sorption zone of the contactor and / or the sorptive separator periodically, for example, during a first portion or period of step (a1 ) or at the start of step (a1 ); and in step (b1 ), wherein the blending at least a portion of the reflux stream into the portion of feed stream for introducing into the second sorption zone of the contactor and / or the sorptive separator.

[0090] Step (a1 ) can be used to recover some moisture from the sorbent in the second sorption zone for use as a portion of at least one of the first regeneration stream and the second regeneration stream. This can significantly reduce the regeneration energy use. Its effectiveness is a function of the sorbent material being used. For the well-known CALF-20 sorbent, for example, up to 30% of the regeneration energy can be reclaimed by this diluted steam recycling process.

[0091] In an alternative embodiment, of the sorptive gas separation process, the process includes: prior to step (a), a step (a1 ) introducing a portion of the feed stream into a second sorption zone of the contactor and / or the sorptive separator, sorbing the first component with the sorbent in the second sorption zone of the contactor and / or the sorptive separator, producing a first recycle stream depleted in the first component and / or enriched in water relative to the feed stream, recovering the first recycle stream from the second sorption zone of the contactor and / or the sorptive separator, recovering a condensate stream from the first recycle stream and blending the condensate into at least one of the first regeneration stream for introducing into the first regeneration zone, the second regeneration stream for introducing into the second regeneration zone, and the at least a portion of the feed stream for introducing into the first sorption zone.

[0092] In further embodiments of the sorptive gas separation process, the process includes:

[0093] • prior to step (a) or step (a1 ), a step (a2) introducing a portion of the feed stream into a third sorption zone of the contactor and / or the sorptive separator, sorbing the first component with the sorbent in the third sorption zone of the contactor and / or the sorptive separator, and producing a second recycle stream depleted in the first component and / or enriched in water relative to the feed stream, recovering the second recycle stream from the third sorption zone of the contactor and / or the sorptive separator, and blending the second recycle stream into at least one of a portion of the feed stream for introducing into the second sorption zone of the contactor and / or the sorptive separator and a second regeneration stream for introducing into the second regeneration zone of the contactor and / or the sorptive separator.

[0094] Step (a2) can be used to improve recovery and mitigate breakthrough of the target or first component, for example, CO2, by cooling of the sorbent in the third sorption zone as a result of the desorption of water or moisture from the sorbent. The second recycle stream dilutes the portion of the feed stream introduced into the second sorption zone and increases cycle time. The increased recovery is at the expense of process productivity and energy efficiency.

[0095] In further embodiments of the sorptive gas separation process, the process includes:

[0096] • after step (a), a step (a3) recovering at least a portion of the first product stream and blending the at least a portion of the first product stream into at least the portion of the feed stream for introducing into at least one of the second sorption zone and the third sorption zone of the contactor and / or the sorptive separator.

[0097] In aspects of the embodiment step (a3), increasing a pressure of the at least a portion of the first product stream by, for example, a blower, a fan, or any other suitable means, prior to blending into the feed stream and introducing into at least one of the second sorption zone and the third sorption zone of the sorptive separator.

[0098] Step (a3) can be used to maintain recovery while increasing sorbent loading of the target or first component and cycle capacity of the contactor and / or the sorptive separator. This can result in reducing the consumption of energy for regeneration at a cost of additional energy consumption for a blower or fan. Productivity is typically not impacted as the longer cycle is also a more productive cycle. Depending on the steam source or heat source availability, this option can be more economically advantageous.

[0099] Figs. 8a and 8b are modeled temperature plots along various axial locations of a contactor for comparing a conventional three-step cycle or process as shown in Fig. 8a to a two-step cycle or process as shown in Fig. 8b. The x-axis is time and the y-axis is temperature.

[0100] In Fig. 8a, with a conventional three-step process, a short drying or condition step 810 of about 6 seconds is followed by a sorption step 812 and a regeneration step 814. It should be noted that the first component or CO2 saturation front can be observed as a sharp temperature rise versus time on the different plots during sorbing step 812. An example is shown as a point 816. During the conditioning step 810, all of the axial temperatures start to decrease at the same time but at different rates with the gas flow exit end of the contactor cooling more slowly than the inlet end of the contactor as the conditioning gas stream comprises a progressively increasing concentration of water as it flows through and in contact with downstream sections of the contactor.

[0101] Fig. 8b is representative of the two-step process comprising a sorption step 822 and a regeneration step 824. The drying or condition step of the three-step process is removed from the two-step process. In sorption step 822 both sorbing and drying are occurring substantially simultaneously. However, for a specific section of the contactor at a distance from the inlet end of the feed stream, the temperature plot illustrates a more marked inflection in temperature versus time corresponding to the first component or CO2 sorption front moving through or along the contactor. While cooling from drying or desorption of water from the contactor is still greater than heating from sorption of CO2, those values are almost equal as indicated by temperature plateaus for the two axial positions along the contactor furthest from the inlet of the feed stream.

[0102] Figs. 9a, 9b, and 9c illustrates multiple methods for integrating different sorbent materials into active forms and shapes of sorbents and contactors. Fig. 9a illustrates a random mixture of particles of a first material 401 and a second material 402 forming a composite material 400. This is the simplest method to combine two different solids. The level of homogeneity of the mixture is driven by particle size, mixing, density difference and the method of application to a substrate and / or its method of forming.

[0103] Fig. 9b illustrates the formation of core / shell structures with a first material 401 being encapsulated by a layer of a second material 402 forming a composite material 400. This structure can be desirable when the outer material is acting as a membrane or a diffusion limiting agent to the inner material. For example, one material used as a shell material can be more tolerant to a component or contamination relative to the material used as the core material.

[0104] Fig. 9c illustrates the assembly of multiple layers comprising a first material 401 and a second material 402 forming a sorbent film, sheet, or structure. This is a simple method to control the distribution of sorbent material in a composite film formed on a substrate. While the layer of first material 401 is more porous in this case than in the core shell structure example in Fig. 9b, there can be kinetic effects associated with the uneven distribution of the material in the thickness of the film. Arrows 420 represents the direction of flow of the gas streams in relation to the sorbent or material.

[0105] These composite structures have been disclosed in International Publication Number WO 2021 / 260647 A1.

[0106] In the context of this invention, a desirable characteristic of the sorbent material is a broad temperature sorption range. This can be achieved through designing a sorbent material with a range of sorbent sites with different energetics. For amine polymers, primary and secondary amines have different basic strengths and heat of adsorption for CO2. Another option is to fabricate composites with a physical mixture of sorbents as described in Figs 9a, 9b, and 9c.

[0107] Figs. 10a and 10b presents the performance of a contactor with a porous amine-based sorbent material described in International Publication Number WO 2023 / 152659 A1 , comparing a two-step process to a conventional three-step process. Fig. 10a is a scatter plot of the relationship between recovery (y-axis) and purity (x-axis) of the CO2 recovered during the process. It is evident that both processes lead to similar performance vis a vis product recovery and purity in this experiment. Fig. 10b presents the amount of steam used for regeneration or steam ratio (y-axis) versus varying CO2 concentration in a feed stream from 4% to 10%, comparing the two-step process with the conventional three-step process. Again, there is not a significant difference between the steam use of the two processes per unit of CO2 recovered. Those results are experimental test results for a sorbent contactor with a volume of 0.8 liters and an axial length of 1 .2 meters using substantially pure steam at near atmospheric pressure as a regeneration stream. A further description of the test and test sample is provided in the example described herein below. Experimental testing was performed with a simulated feed stream with a CO2 concentration of 4% and 10%, with 5% moisture and the balance of N2.

[0108] An optional strategy for using the two-step process with a sorbent with high capture efficiency at Ts-reg. includes the use of another sorbent in a first stage sorptive separator with a reduced target or first component, for example, CO2 recovery. The use and configuration of the first and second stages achieves a desired recovery rate of greater than 80% by reprocessing a portion of the effluent from the first stage.

[0109] Fig. 11 is a schematic diagram of a sorptive gas separation system comprising a first stage sorptive separator and a second stage sorptive separator where a first stage two-step sorptive separation process is carried out by a first stage sorptive separator 610 with sorbents on one or more contactors (both not shown in Fig. 11 ) separated into two zones. In zone 610a the sorption step of the two-step process occurs where the sorbent in and / or on the contactor(s) are contacted by a feed stream 601 containing the target or first component, for example, CO2, to form two different streams, a moist first product stream 611 at the beginning of the sorption step and a dry first product stream 612 for the remainder or the end of the sorption step. In a second zone 610b the regeneration step of the two-step process occurs where the sorbent contactor(s) are contacted by a portion of a regeneration stream 604 comprising steam to form a second product stream 613 enriched in the target or first component, for example, CO2 relative to feed stream 601 . When the sorbent in sorptive separator 610 is a limited Ts-reg sorption, moist first product stream 611 contains greater than 5% of the CO2 from feed stream 601 . It is desirable to recover this diluted CO2 by using a second stage sorptive separator 620 using the two-step process with two zones. In zone 620a the sorption step of the two-step process occurs where the sorbent in and / or on the contactor is contacted by moist first product stream 611 as a feed stream for second stage sorptive separator 620 and forms a first product stream 621 depleted in CO2 relative to moist first product stream 611 . In zone 620b the regeneration step of the two-step process occurs when the sorbent in and / or on the contactor is contacted by a portion of the regeneration stream 604 comprising steam to form a second product stream 623 enriched in CO2 relative to moist first product stream 611 . Regeneration stream 604 employed for the first stage and the second stage is sourced from the same stream, alternatively they can be sourced from different streams.

[0110] For second stage sorptive separator 620, the sorbents’ CO2 sorption capacity at Ts-reg is equal to or greater than 20% of the sorbents’ CO2 capacity at Ts- sorp, whereas for first stage sorptive separator 610, the sorbent can be a different material with a reduced Ts-reg capacity as compared to the sorbent used in second stage sorptive separator 620.

[0111] The benefit of this arrangement is that less sorbent with high Ts-Reg capacity is required as compared to a single stage two-step device.

[0112] As the oxidative stability of amine sorbents is more challenging than, for example, the CALF-20 MOF sorbent, a hybrid sorbent approach utilizing a first stage sorbent with increased lifetime combined with a second stage amine based sorbent can be beneficial for commercial deployment. While sorptive systems with two stages have been proposed, the integration of the two-step process described herein with a two-stage sorptive separator design can offer significant advantages to improve overall system energy efficiency and balance of plant simplicity and limiting the quantity of high temperature sorbent used in the overall process.

[0113] In an embodiment, a sorptive gas separation process is carried out using two-stages with the second stage using the novel two-step process disclosed herein with a sorbent material characterized by a Ts-reg first component or CO2 capacity being equal to or greater than 20% of the Ts-sorp. capacity.

[0114] Economically viable separation of a first component or CO2 from a combustion or flue gas using solid sorbents desirably utilizes at least one of: very inexpensive sorbents, a rapid cycle, and rapid kinetic sorbent materials and structures. An example of such structures is disclosed in International Publication Number WO 2021 / 240476 A1 . Those structures can enable about 90% recovery of CO2 with a contact time shorter than about 1 second. Contactors formed from parallel channels separated by thin walls formed of sorbent material are operated mostly adiabatically. This presents the challenge of injecting or removing heat from an external source that is not a flue gas or a regenerative gas.

[0115] For optimized sorbent utilization, it is desirable to control sorbent temperature in the proposed two-step process utilizing a sorbent suitable for rapid cycles. Sorption and desorption of water and the first component, for example, CO2, through a full cycle has a moderate impact on heat carried from cycle to cycle and stored on the solids. Controlling the temperature of the feed stream and / or regeneration stream can have a moderate impact on cycle temperatures in the process, however it is a slow multicycle effect and cannot be used effectively within an individual process step. Therefore, it can be desirable to introduce an additional exothermic or endothermic process with the sorbent contactor to further and rapidly enable the addition or removal of heat.

[0116] In an embodiment, water in the form of liquid droplets or a fine mist can be added and introduced into at least a portion of a feed stream for introduction into a contactor and / or sorptive separator, or a zone of a contactor and / or sorptive separator. The introduction of water in a liquid phase result in an endothermic reaction and process within the contactor which accelerates the cooling and reduction in temperature of at least a portion of the contactor, or a portion of a contactor within a zone of a sorptive separator.

[0117] In an embodiment, the quantity of water introduced into the feed stream is controlled such that a quantity of vaporized liquid water or steam in the contactor or zone of a contactor is equal to or greater than about 20% of the steam in an effluent or product stream, for example, the first recycle stream or the first product stream of a sorbing step, for example steps (a1 ) or (a) as disclosed above.

[0118] In a further embodiment of the sorptive gas separation process, a sorbing step, for example steps, (a1 ) or (a) is further divided into two steps and / or periods. In a first step and / or period, water in a liquid phase, for example, in the form of suspended droplets or a mist, is added and introduced into at least a portion of a feed stream followed by a second step and / or period without adding and introducing water into the feed stream. In a further embodiment of the sorptive gas separation process, a sorption step further comprises adding and / or introducing water to at least a portion of the feed stream during a first portion or period of a sorbing step for example steps, (a1 ) or (a), or at the start of the sorption step.

[0119] As a multi-component stream employed and / or a feed stream, is typically cooler than the sorbent and / or contactor at the beginning of a sorbing step, evaporation of the liquid water added to the feed stream can occur upon contact of the liquid water with the sorbent and / or contactor when the sorbent temperature is, for example, equal to or greater than about 90°C, or equal to or greater than about 100°C.

[0120] In a further embodiment of the sorptive gas separation process, during a regeneration step, water in the form of liquid droplets or a fine mist are added and introduced into at least a portion of a regeneration stream for introduction into a contactor and / or sorptive separator, or a zone of a contactor and / or sorptive separator. The introduction of water in a liquid phase can result in an exothermic reaction and process within the contactor which accelerates the heating and increase in temperature of at least a portion of the contactor, or portion of a contactor within a zone of a sorptive separator. In an embodiment, controlling at least one of the quantity of water added or introduced, the droplet size of the water introduced, and the distribution of introduction points along an axial direction of the flow of the feed stream or the regeneration stream through the contactor, to set a desired amount and / or rate of cooling or decrease in temperature during the feed or sorption step and / or the heating or increase in temperature during the regeneration step.

[0121] The distribution of cooling and heating of the sorbent and / or contactor in a direction of the flow of the feed stream or the regeneration stream through the contactor can be controlled by selecting and controlling the droplet size as well as the shape of the flow channels and the degree of turbulence and change in flow direction. This is due to the fact that liquid droplets suspended in a gas have much greater inertia than the surrounding gas.

[0122] It is important to note that the amount of water remaining on the sorbent at the completion of the sorption step affects the amount of water sorbed during the regeneration step. Adding a supplemental cooling step by adding water droplets to a portion of the feed stream in addition to cooling the sorbent directly can also reduce the amount of steam sorbed and / or introduced in the subsequent regeneration step by increasing the moisture content of the sorbent prior to the regeneration step.

[0123] In a further embodiment of the sorptive gas separation process, the process includes controlling, introducing and / or dispensing water in liquid phase in the feed stream with a ratio of water to feed stream and the duration of the introduction to provide an additional reduction in temperature at an inlet end of the feed stream of the sorbent contactor of equal to or greater than about 10°C.

[0124] Porous basic resin sorbents with amines that are suitable for the two-step sorptive gas separation process described herein have the following properties, they:

[0125] 1 ) can comprise pores including macropores, mesopores, micropores and / or a combination of these.

[0126] 2) can comprise amine groups with at least one of linear and cyclic primary amines, secondary amines, or mixture thereof with linear or cyclic amines with the following structure: a. Cyclic amine: or 4 b. Linear amine greater but less than 12, n = 0 to 12, n can be 2 or 3; A also can = oxygen, nitrogen, sulfur, -

[0127] CH=CH-, -C=C-, -C=O, -SO2- or a combination thereof.

[0128] 3) can contain in addition to an amine based sorbent, a basic function which optionally includes amidine, guanidine groups or other organic bases.

[0129] 4) The Nitrogen weight percent of the sorbent is equal to or greater than 6%, and preferably equal to or greater than 7%, and most preferably equal to or greater than 8%.

[0130] 5) The amine polymer sorbent is as disclosed in International Publication Number WO 2024 / 110902 A1 .

[0131] In an embodiment, the sorptive gas separation process described herein is used for separation of a target or first component, for example, CO2, from a multicomponent gas stream and provides a recovery of a second product stream with a concentration of greater than 90% of the first component, for example, CO2, on a dry basis and a recovery of greater than 80% of the first component, for example, CO2. The sorptive gas separation process described herein uses a sorbent which comprises a solid sorbent material that is porous and is further characterized by a sorption capacity for CO2 at Ts-reg. of at least 20% of the sorption capacity for the first component, for example, CO2 of the sorbent at Ts-sorp.

[0132] In a further embodiment, the Ts-swing of the cyclic sorption process is greater than 30°C. In an embodiment, the sorptive gas separation process described herein is used for separation of a target or first component, for example, CO2, from a multicomponent gas stream and provides a recovery of the first component, for example, CO2 in a second product stream with a concentration of greater than 90% of the first component, for example, CO2, on a dry basis and a recovery of greater than 80% of the first component, for example, CO2. The sorptive gas separation process described herein uses a sorbent which comprises a solid sorbent material that is porous and is further characterized by a sorption capacity for the first component, for example, CO2 at 100°C of equal to or great than 20% of the sorption capacity for the first component, for example, CO2 at 60°C.

[0133] In an embodiment, the sorptive gas separation process uses a polymeric amine sorbent comprised of primary amines.

[0134] In an embodiment, the sorptive gas separation process uses a solid sorbent with a weight fraction of nitrogen of greater than 6%.

[0135] In an embodiment, the sorptive gas separation process uses a solid sorbent with pores including macropores, mesopores and micropores with a combined pore volume of greater than 0.4 ml / g of sorbent.

[0136] In an embodiment, a two stage sorptive gas separation process utilizes two sequential sorptive gas separation processes on at least a fraction of a feed stream comprising a target or first component, for example, CO2, recovering equal to or greater than about 80% of the target or first component, for example, CO2 in the feed stream. At the beginning or at the end of a sorption step (a) of a first stage sorptive gas separation process, a portion of the first product stream recovered is used as the feed stream with a reduced CO2 concentration and at a reduced flow volume for the second stage sorptive gas separation process and second stage sorptive separator

[0137] The benefits of this approach can be the ability to select different sorbent materials for each stage when two separate sorptive separators are employed for the two-stage sorptive gas separation process. In particular, the first stage sorptive separator can not have a sorbent with a high temperature CO2 sorption capacity but can be more durable and therefore last longer in this application. The second stage sorptive separator and gas separation process would be that of the current invention and include a sorbent with high sorption capacity for the target component, for example, CO2, equal to or greater than about 90°C or at equal to or greater than about 100°C.

[0138] Example:

[0139] A contactor comprising a primary amine sorbent with a bulk density of about 140 kg / m3configured in 1.2m long sheets in the direction of flow and a 1-inch square cross-section was operated and compared with a two-step process and a conventional three-step process to separate and capture CO2 from a feed stream comprising 4% CO2 and 5% H2O, and the balance N2. Regeneration of the sorbent was performed using a regeneration stream comprising a steam stream near atmospheric pressure with flow and duration adjusted to reach about 90% CO2 recovery from the feed stream. The three-step cycle used dry air (1 % H2O) as the conditioning gas to remove part of the water adsorbed on the sorbent during a conditioning step, whereas the two-step cycle does not use a separate conditioning step and conditioning gas. Cycle time was adjusted to maximize productivity of the system expressed as metric tons per day per cubic meter of sorbent contactor (TPD / m3).

[0140] The test was repeated with a feed stream comprising 10% CO2 and the results of these tests are presented in Figs. 10a and 10b.

[0141] Table 1 presents the key performance indicators for the two different cycles tested.

[0142] Table 1 : KPI (Key Performance Indicators) comparison for the conventional three-step sorptive gas separation process versus the novel two-step sorptive gas separation process using a high temperature adsorbing amine sorbent.

[0143] Table 1 data illustrates that with this particular sorbent, high recovery was obtained in the two step sorptive gas separation process while not increasing the amount of steam used for regeneration or significantly reducing the purity of the product recovered.

Claims

WHAT IS CLAIMED IS:1 . A sorptive gas separation process for separating a first component from a multi-component gas stream, the process comprising:(a) introducing the multi-component gas stream as at least a portion of a feed stream with a first component, into a first sorption zone of a sorptive separator with a sorbent, sorbing the first component with the sorbent in the first sorption zone, producing a first product stream depleted in the first component relative to the feed stream, and recovering the first product stream from the first sorption zone, and(b) introducing a first regeneration stream comprising steam into a first regeneration zone of the sorptive separator, desorbing the first component from the sorbent in the first regeneration zone, producing a second product stream enriched in the first component relative to the feed stream and recovering the second product stream from the first regeneration zone, wherein the sorbent has a sorption capacity for the first component at Ts- reg. of at least 20% of the sorption capacity the first component at Ts-sorp.

2. The process of claim 1 , wherein the sorbent comprises amine groups with at least one of linear and cyclic primary amines, secondary amines, or a mixture thereof with linear or cyclic amines.

3. The process of claim 2, wherein the cyclic amine isleast one of oxygen, nitrogen, sulfur, -CH=CH-, -C=C-, -C=O, -SO2- or any combination thereof.

4. The process of claim 2, wherein the linear amine isgreater and less than 12, A is oxygen, nitrogen, sulfur, -CH=CH-, -C=C-, -C=O, -SO2- or any combination thereof.

5. The process of any one of claims 1 to 4, wherein the sorbent comprises an amine based amidine sorbent, guanidine groups or other organic bases.

6. The process of any one of claims 2 to 5, wherein the sorbent comprises a nitrogen weight percentage, the nitrogen by weight is greater than 6%.

7. The process of any one of claims 1 to 6, further comprising switching between at least one of step (a) to step (b), and step (b) to step (a), when a Ts-swing is equal to or greater than 30°C.

8. The process of any one of claims 1 to 7, further comprising prior to step (b), a step (b1 ) introducing a second regeneration stream comprising steam into a second regeneration zone of the sorptive separator, desorbing the first component from the sorbent, and producing a reflux stream enriched in the first component relative to the feed stream, recovering the reflux stream from the second regeneration zone, and blending at least a portion of the reflux stream into the feed stream for introducing into at least one of the first sorption zone or a third sorption zone.

9. The process of any one of claims 1 to 8, further comprising prior to step (a), a step (a1 ) introducing a portion of the feed stream into a second sorption zone of the sorptive separator, sorbing the first component with the sorbent in the second sorption zone, producing a first recycle stream enriched in water relative to the feed stream, recovering the first recycle stream from the second sorption zone, and blendingthe first recycle stream into at least one of the first regeneration stream for introducing into the first regeneration zone, the second regeneration stream for introducing into the second regeneration zone, and the feed stream for introducing into the first sorption zone.

10. The process of any one of claims 1 to 8, further comprising prior to step (a), a step (a1 ) introducing a portion of the feed stream into a second sorption zone of the sorptive separator, sorbing the first component with the sorbent in the second sorption zone, producing a first recycle stream enriched in water relative to the feed stream, recovering the first recycle stream from the second sorption zone, recovering a condensate from the first recycle stream and blending the condensate into at least one of the first regeneration stream for introducing into the first regeneration zone, the second regeneration stream for introducing into the second regeneration zone, and the feed stream for introducing into the first sorption zone.11 . The process of claim 9 or 10, further comprising introducing water to the portion of the feed stream for introduction into the second sorption zone.

12. The process of any one of claims 9, 10, or 11 , further comprising prior to step (a1 ), a step (a2) introducing a portion of the feed stream into a third sorption zone of the sorptive separator, sorbing the first component with the sorbent in the third sorption zone, and producing a second recycle stream enriched in water relative to the feed stream, recovering the second recycle stream from the third sorption zone, and blending the second recycle stream into at least one of the feed stream for introducing into the second sorption zone and the second regeneration stream for introducing into the second regeneration zone.

13. The process of any one of claims 1 to 12, further comprising after step (a), a step (a3) recovering at least a portion of the first product stream and blending the at least portion of the first product stream into the feed stream for introducing into at least one of the second sorption zone and the third sorption zone.

14. The process of any one of claims 1 , 8, 9, 10, or 12, wherein the first component is carbon dioxide.

15. The process of claim 1 , wherein the multi-component gas stream is a combustion gas stream, a flue gas stream, a process gas stream, an air stream, a biogas stream, or combinations thereof.

16. The process of any one of claims 1 , 7, 9, 10, and 13, further comprising in step (a), the sorbing of the first component on the sorbent occurs when a temperature of the sorbent is at a sorbent temperature of equal to or greater than 90°C.

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