Cryogenic recovery of carbon dioxide from a hydrogen manufacturing plant

Abstract

The present disclosure relates generally to methods and systems for the generation of high purity hydrogen with the cryogenic recovery of carbon dioxide (CO2). The disclosure can involve an integrated system to make hydrogen in a hydrogen manufacturing unit and separate process gases containing CO2 and various other gases with integrated dryer adsorber vessel regeneration to achieve moderate to high capture rates of CO2. In addition, but not by way of limitation, this disclosure relates to methods to reduce the carbon footprint and improve process efficiencies in a hydrogen manufacturing unit or process with CO2 removal.

Description

CRYOGENIC RECOVERY OF CARBON DIOXIDE FROM A HYDROGEN MANUFACTURING PLANTTechnical Field

[0001] The present disclosure relates generally to methods and systems for the generation of high purity hydrogen with the cryogenic recovery of carbon dioxide (CO2). The disclosure can involve an integrated system to make hydrogen in a hydrogen manufacturing unit and separate process gases containing CO2and various other gases with integrated dryer regeneration to achieve moderate to high capture rates of CO2. In addition, but not by way of limitation, this disclosure relates to methods to reduce the carbon footprint and improve process efficiencies in a hydrogen manufacturing unit or process with CO2 removal.Background

[0002] Hydrogen manufacturing units based on the reforming of hydrocarbons with steam is a large emitter of CO2 generated from the conversion and combustion of the hydrocarbon feeds. Reduction and capture of CO2 from process streams in a hydrogen manufacturing unit is therefore of great interest in order to combat climate change by minimizing the release of greenhouse gases. Recovery of the CO2 from process gas streams in a hydrogen manufacturing unit can be achieved through a number of different technologies at different process locations in the unit. One technology and location that is gaining attention is the removal of the CO2 from a process gas (e.g., containing CO2, CO, H2, light hydrocarbons, water, and / or inert gases) at a single flowsheet location in the hydrogen purification block using cryogenic technology. However, improved methods of reducing the carbon footprint and improving process efficiencies for CO2 removal from hydrogen manufacturing unit process gases are desirable.Summary

[0003] According to an aspect of the present disclosure, there is provided a method for processing a stream comprising residual CO2 and at least one of H2, helium, CO, CH4,N2, argon, or any combinations thereof, comprising: dividing said stream into at least a first stream and a second stream, wherein the first stream is a CO2-depleted stream and the second stream is a CO2-rich stream; routing at least a first portion of the first stream to a heater to produce a heated regeneration gas for an adsorption process, wherein the heater heats the portion of the first stream with residual heat from a plant applying a reforming reaction that converts CH4 with CO2 and / or H2O into H2 and CO, or a water gas shift section that converts CO and H2O into H2 and CO2, or any combination thereof; routing at least a first portion of the heated regeneration gas to an adsorber vessel to regenerate the adsorber vessel; and recovering a first spent regeneration gas stream from the adsorber vessel as a feed to said plant. The first stream may be depleted in CO2 relative to the stream comprising residual CO2 and at least one of H2, helium, CO, CH4, N2, argon, or any combinations thereof. The second stream may be enriched in CO2 relative to the stream comprising residual CO2 and at least one of H2, helium, CO, CH4, N2, argon, or any combinations thereof, and hence may also be referred to as a “CO2-enriched stream”. The first stream may have a lower CO2 content than the second stream.

[0004] The method may comprise routing a second portion of the first stream to the adsorber vessel, bypassing the heater; routing a second spent regeneration gas stream from the adsorber vessel to the heater to produce a heated second spent generation gas stream; and recovering the heated second spent generation gas stream as a feed to said plant.

[0005] The first portion of the first stream and the second portion of the first stream may have substantially the same composition and / or the same pressure. The adsorber vessel may be in regeneration and another adsorber vessel may be in a drying step. The adsorber vessel in regeneration may be at the same pressure as the adsorber vessel that is in a drying step. For example, the pressure difference between the two adsorber vessels may be 1.5 bar or less, 1 bar or less, or 0.5 bar or less.

[0006] According to an aspect of the present disclosure, there is provided a method for processing a stream comprising residual CO2 and at least one of H2, helium, CO, CH4, N2, argon, or any combinations thereof, comprising: dividing said stream into at least a first stream and a second stream, wherein the first stream is a CO2-depleted stream andthe second stream is a CO2-rich stream; routing at least a first portion of the first stream to a first adsorber vessel as regeneration gas; routing a second portion of the first stream together with a first spent regeneration gas stream from the first adsorber vessel to a heater to produce a heated regeneration gas for an adsorption process, wherein the heater heats the second portion of the first stream and the first spent regeneration gas stream with residual heat from a plant applying a reforming reaction that converts CH4 with CO2 and / or H2O into H2 and CO, or a water gas shift section that converts CO and H2O into H2 and CO2, or any combination thereof; routing at least a first portion of the heated regeneration gas to a second adsorber vessel to regenerate the second adsorber vessel; and recovering a second spent regeneration gas stream from the second adsorber vessel as a feed to said plant. The first stream may be depleted in CO2 relative to the stream comprising residual CO2 and at least one of H2, helium, CO, CH4, N2, argon, or any combinations thereof. The second stream may be enriched in CO2 relative to the stream comprising residual CO2 and at least one of H2, helium, CO, CH4, N2, argon, or any combinations thereof, and hence may also be referred to as a “CO2-enriched stream”. The first stream may have a lower CO2 content than the second stream.

[0007] The method may comprise combining the second spent regeneration gas stream with a second portion of the heated regeneration gas to provide a combined stream as the feed to said plant. The first portion of the heated regeneration gas and the second portion of the heated generation gas may have substantially the same composition. The first and second adsorber vessels may be in regeneration and a third absorber vessel may be in a drying step. The first absorber vessel, the second absorber vessel and the third absorber vessel may be at the same pressure. For example, the pressure difference between the first, second and third adsorber vessels may be 1.5 bar or less, 1 bar or less, or 0.5 bar or less.

[0008] The reforming reaction or water gas shift section may produce H2 from the spent regeneration gas stream.

[0009] The method may comprise recovering the second stream.

[0010] The adsorption process may be a temperate swing adsorption, TSA, process. The adsorption process may use an adsorbent configured to adsorb water butessentially not adsorb CO2. The adsorbent may therefore be selective for water such that it adsorbs water more than it adsorbs CO2.

[0011] The stream comprising residual CO2 may comprise from 5 mole% CO2 to 20 mole% CO2, 7 mole% CO2 to 20 mole% CO2, or 10 mole% CO2 to 20 mole% CO2. The stream comprising residual CO2 may comprise from 5 mole% H2 to 20 mole% H2, from 7 mole% H2 to 20 mole% H2, or from 10 mole% H2 to 20 mole% H2. The stream comprising residual CO2 may be generated in a hydrogen manufacturing plant.

[0012] The hydrogen manufacturing plant may comprise a dryer comprising: i. the adsorber vessel, or ii. the first adsorber vessel and the second adsorber vessel. The dryer may be a temperature swing adsorption, TSA, dryer. The dryer may be upstream of a CO2 recovery system.

[0013] The hydrogen manufacturing plant may comprise at least one of: a) a syngas production unit, b) a water gas shift unit, c) a heat recovery section, d) a H2 purification section, e) a compressor, f) a first phase separator generating a first condensate, g) a second phase separator, and h) a distillation column. The hydrogen manufacturing plant may comprise an expansion valve configured to expand the first condensate from the first phase separator. The heater can be a heat exchanger of the heat recovery section. For example, the heat exchanger may be configured to recover heat from hot process gas leaving the water gas shift unit, or recover heat from steam generated from the heat recovery section. Alternatively, the heater can be part of the syngas production unit. For example, the heater may be a radiant coil or a convection coil within a heater of the syngas production unit. The heater may be part of a heat recovery section which may be arranged for recovering heat from the hot flue gas from the syngas production unit, or from steam generated from heat recovered from the hot flue gas from the syngas production unit.

[0014] The first phase separator may generate the stream comprising residual CO2. The hydrogen manufacturing plant may comprise a system to recover at least a portion of the stream comprising residual CO2 and use that portion of the stream to regenerate a dryer of the hydrogen manufacturing plant.

[0015] The first phase separator may generate a first vapor. The hydrogen manufacturing plant may comprise: a) a CO2 recovery system separating the first vaporinto a stream enriched in at least one of H2, helium, CO, CH4, N2, argon and containing residual CO2, and a second stream depleted in at least one of H2, helium, CO, CH4, N2, argon; and b) a system to recover at least a portion of the stream enriched in at least one of H2, helium, CO, CH4, N2, argon and containing residual CO2, and use it to regenerate a dryer of the hydrogen manufacturing plant. The CO2 recovery system may be a pressure swing adsorption system.

[0016] The distillation column may be operated without an overhead condenser.

[0017] The syngas production unit may comprise a reformer. The reformer may comprise an SMR, an ATR, a POX, a heat-exchanger reformer installed in series, a heatexchanger reformer installed in parallel, a recuperative reformer, an electric reformer, or any combination thereof.

[0018] The hydrogen manufacturing plant may comprise a heat exchanger after the compressor configured to chill a compressed feed stream. The hydrogen manufacturing plant may comprise a cold box with a refrigeration system. The cold box may be installed downstream of a dryer system. The cold box may be configured to cool a dried feed stream at least partially using an overhead vapor stream from the distillation column, the first phase separator, the second phase separator, or any combination of vapor streams thereof. The multi-stream heat exchanger may be configured to use a condensate from the second phase separator or a bottoms stream from the distillation column to chill the compressed feed stream. The cold box and first phase separator may be configured to at least partially condense CO2 in a single stage. The refrigeration system may comprise a mixed refrigerant working fluid. The mixed refrigerant working fluid may comprise at least two components, and / or CO2. One of the at least two components may be CO2. The refrigeration system may comprise a refrigerant loop with at least two different pressure levels. The refrigeration system may be configured to operate at three or more pressure levels.Brief Description of the Drawings

[0019] FIG. 1 illustrates a process flow diagram for a CO2 removal process from a hydrogen manufacturing unit according to some embodiments of the disclosure.

[0020] FIG. 2 illustrates a process flow diagram for a CO2 removal process from a hydrogen manufacturing unit according to some embodiments of the disclosure.

[0021] FIG. 3 illustrates a process flow diagram for a CO2 removal process from a hydrogen manufacturing unit according to some embodiments of the disclosure.

[0022] FIG. 4 illustrates a process flow diagram for a CO2 removal process from a hydrogen manufacturing unit according to some embodiments of the disclosure.

[0023] FIG. 5 illustrates a process flow diagram for a refrigeration circuit integrated with a CO2 removal process from a hydrogen manufacturing unit according to some embodiments of the disclosure.

[0024] FIG. 6 illustrates a process flow diagram for a refrigeration circuit integrated with a CO2 removal process from a hydrogen manufacturing unit according to some embodiments of the disclosure.

[0025] FIG. 7 illustrates a process flow diagram for a refrigeration circuit integrated with a CO2 removal process from a hydrogen manufacturing unit according to some embodiments of the disclosure.

[0026] FIG. 8 illustrates a process flow diagram for a refrigeration circuit integrated with a CO2 removal process from a hydrogen manufacturing unit according to some embodiments of the disclosure.

[0027] FIG. 9 illustrates a process flow diagram for the operation and regeneration of a temperature-swing adsorption dryer with a single adsorber in regeneration with successive heating and cooling steps (phases) according to some embodiments of the disclosure.

[0028] FIG. 10 illustrates a process flow diagram for the operation and regeneration of a temperature-swing adsorption dryer with multiple adsorber vessels in regeneration, allowing for parallel heating and cooling steps (phases) according to some embodiments of the disclosure.Detailed Description

[0029] The disclosure describes novel processes and / or systems for the removal of the CO2 from a process gas of a hydrogen manufacturing unit containing, for example,C02, CO, H2, light hydrocarbons, water, and / or inert gases using cryogenic technology. The disclosed processes and systems improve the energy efficiency of the cryogenic removal in comparison to existing technologies, with moderate to high CO2capture rates (e.g., 85 to 95 % of all carbon contained in the feed gas) and generation of high purity hydrogen (e.g., from 99.5 to 99.99 % purity) for any combination of reforming technologies (e.g., adiabatic pre-reforming, steam methane reforming, autothermal reforming, partial oxidation, recuperative reforming, heat-exchanger reforming, or any combination thereof) and hydrocarbon feedstock (natural gas, LPG, naphtha from fossil fuels, biogenic or other origin, or any mixtures thereof).

[0030] The disclosure describes cryogenic CO2capture processes and related refrigeration circuits coupled to hydrogen manufacturing processes. More specifically, the disclosure describes cryogenic CO2capture units, systems, and processes, in which the CO2is recovered after separation from lighter components through compression and partial condensation in a cryogenic separation section using external refrigerant as described in detail for various embodiments below. Existing processes focus either on different cryogenic CO2capture units (and refrigeration technologies), or on the overall integration in the hydrogen manufacturing unit and require complex additional CO2recovery downstream of the cryogenic unit.

[0031] The disclosure also describes full integration of recycle streams with the process for regeneration of the dryer adsorber vessels, maximizing process efficiencies compared with conventional regeneration processes.

[0032] Thus, in some embodiments, a syngas produced from a hydrogen production unit (e.g., using steam reforming) is treated in a purification section comprising a cryogenic section, such that the stream comprising CO2, CO, H2, light hydrocarbons, water, and / or inert gases can be separated into at least:a stream rich in hydrogen, containing more than 99.5 % (by volume / mole) of H2a stream rich in CO2, containing more than 99.5 % (by volume / mole) of CO2an off-gas stream containing residual molecules, at least one or more of CO, CH4, N2, Ar, He, H2, CO2, or any combinations thereof.The cryogenic separation section, dryer regeneration, and related operations are described in detail below.Hydrogen Manufacture

[0033] In some embodiments, hydrogen can be produced in a hydrogen manufacturing unit with a hydrocarbon feed stream. In some embodiments, the source of the hydrocarbon feed stream can be from fossil origin, such as natural gas, LPG, butane, naphtha, or any combinations thereof, for example. In some embodiments the source of the hydrocarbon feed stream can be from biogenic origin such as gaseous or liquid waste streams from hydroprocessing of vegetable oils, hydrogenated esters and fatty acids, or any combinations thereof, for example. In some embodiments, the source of the hydrocarbon feed stream can be generated from synthesis gas via Fischer-Tropsch or other reactions, including e-fuels and renewable fuels generated from methanation of CO2 and renewable H2, for example). In some embodiments, the source of the hydrocarbon feed stream can be from any of the above examples, including any and all combinations thereof.

[0034] In some embodiments, the hydrogen manufacturing unit or step can, with aid of steam and / or oxygen, convert the hydrocarbon feed into a syngas comprising H2 and CO. In some embodiments, the system or process can include a water gas shift unit / step where the syngas is converted to hydrogen and CO2 (shifted syngas). This system or process can, in some embodiments, also include a heat recovery section that can cool the shifted syngas and condense excess steam as a process condensate. In some embodiments, the cooled shifted syngas is directed to a purification section that can comprise a H2 Pressure Swing Adsorption (PSA) unit. In some embodiments, the PSA unit can generate at least two product streams: a first product stream recovered at high pressure (e.g., close to the PSA feed inlet pressure) comprising most of the H2 and substantially no CO2 (e.g., only a small amount), and a CO2-rich second product stream recovered at low pressure that comprises the remaining components (e.g., CO2, and at least one of CO, CH4, N2, Ar, H2, or H2O).CO2-Rich Stream (Second Product Stream)

[0035] As noted, in some embodiments, the CO2-rich (second product) stream comprises CO2, and at least one of CO, CH4, N2, Ar, H2, H2O, or any combinations thereof. In some embodiments, the CO2-rich stream can comprise from 5 to 98 mole% CO2. In some embodiments, the CO2-rich stream can comprise from 0.1 mole% to 20 mole% CO. In some embodiments, the CO2-rich stream can comprise from 0.1 mole% to 20 mole% CH4. In some embodiments, the CO2-rich stream can comprise from 0.1 mole% to 80 mole% N2. In some embodiments, the CO2-rich stream can comprise from 0 mole% to 30 mole% Ar. In some embodiments, the CO2-rich stream can comprise from 0 mole% to 10 mole% He. In some embodiments, the CO2-rich stream can comprise from 0 mole% to 60 mole% H2. In some embodiments, the CO2-rich stream can comprise from 0 mole% to 30 mole% H2O.

[0036] In some embodiments where the CO2-rich stream pressure is low, it can be compressed to high pressure. For example, the CO2-rich stream can be compressed to a pressure above 20 bar (abs) (e.g., above 25 bar (abs), above 30 bar (abs), above 35 bar (abs), above 40 bar (abs), above 50 bar (abs), above 60 bar (abs), from 20 bar (abs) to 100 bar (abs), from 20 bar (abs) to 80 bar (abs), from 20 bar (abs) to 70 bar (abs), from 20 bar (abs) to 60 bar (abs), from 20 bar (abs) to 50 bar (abs), from 20 bar (abs) to 35 bar (abs), or from 35 bar (abs) to 60 bar (abs)). In some embodiments, the CO2-rich stream is compressed until the CO2 partial pressure is greater than 15 bar (abs) (e.g., greater than 16 bar (abs), greater than 17 bar (abs), greater than 18 bar (abs), greater than 19 bar (abs), greater than 20 bar (abs), from 15 bar (abs) to 20 bar (abs), or from 20 bar (abs) to 25 bar (abs)). In some embodiments, the compression can take place in a multistage compressor with intercooling. In some embodiments, the CO2-rich stream is already at a high enough pressure and / or has a high enough CO2 partial pressure that it is not compressed. In some embodiments, a higher partial pressure of CO2, and therefore a higher total pressure is preferred.Drying

[0037] In some embodiments, the CO2-rich stream can be dried in a dryer. In some embodiments, the dryer is a temperature swing adsorption-based (TSA) dryer. In someembodiments, the CO2-rich stream to the dryer can be chilled against the cold streams available from the cold process described herein in a first heat exchanger. In some embodiments, the CO2-rich stream to the dryer can be chilled while maintaining a margin above the hydrate formation of the stream. Any remaining water that is not knocked out by the chilling heat exchanger can be removed by the dryer, for example.

[0038] In some embodiments, the dryer is a temperature swing adsorption dryer system that uses an adsorption process that is based on the adsorption of vapor phase water at low temperature (e.g., 10 °C to 50 °C) on a solid adsorbent selective for water. In some embodiments, the dryer comprises an adsorbent configured to adsorb water but essentially not CO2, i.e. the adsorbent is configured or selected such that the stream produced by the dryer is essentially free of water (e.g. the water content has been reduced to 100 ppm v or less, 50 ppm v or less, 30 ppm v or less, 15 ppm v or less, or 1 ppm v or less), but includes more than 80%, more than 90%, more than 95%, or more than 99% of the CO2 in the CO2-rich stream fed to the dryer. In some embodiments, the adsorbent can be a molecular sieve, zeolite, aluminosilicate, silica gel or activated carbon type of material, or any combinations thereof.

[0039] In some embodiments, the adsorbent can be regenerated by heating the adsorber vessel with a hot (e.g., 150 °C to 300 °C) regeneration gas to desorb the adsorbed moisture, followed by cooling the regenerated adsorber bed. In some embodiments, the regenerated adsorber vessel is cooled to the temperature at which the adsorption takes place. In some embodiments, the regenerated adsorber vessel is cooled with cold regeneration gas. In some embodiments, the regeneration gas is taken, at least in part, from the treated product stream from the adsorption step of the temperature swing adsorption process.

[0040] In some embodiments, at least a portion of the first low pressure (LP) flash gas, at least a portion of the second low pressure (LP) flash gas, at least a portion of the high pressure (HP) flash gas (all described below), or any combinations thereof, can be used as a cold regeneration gas for the cooling step of the temperature swing adsorption dryer, recovering heat from a hot adsorber bed.

[0041] In some embodiments, the drying can take place after the compression step. In other embodiments, the drying can take place prior to the compression step. Insome other embodiments, the drying can take place between compression steps. Following the drying, in some embodiments the dried stream can be fed to a cold box.Cold-box (multi-stream heat exchanger)

[0042] In some embodiments, the dried stream is (further) cooled using evaporating refrigerant in one or more passes through a cold box. In some embodiments, the cold box is a multi-stream heat exchanger. In some embodiments, the refrigerant is a mix of two or more components. In some embodiments, the refrigerant is a mix of two components. The dried stream can be cooled to a temperature that allows partial condensation of the stream, for example, generating a liquid stream, CO2-rich condensate. In some embodiments, because water has been removed by the dryer, the condensate will comprise primarily CO2 (e.g., more than 50 mole% CO2, more than 60 mole% CO2, more than 70 mole% CO2, more than 80 mole% CO2, or more than 90 mole% CO2,) and optionally containing some dissolved light gases (including CH4, CO, N2, H2, Ar, He, O2, or any combinations thereof).Phase Separation and Use of Flash Gas

[0043] In some embodiments, the CO2-rich condensate can be separated from the vapor phase in a phase separator, producing a first CO2-rich liquid, and a first CO2-depleted flash gas (HP flash gas). In some embodiments, the first CO2-depleted flash gas can be used to cool down the (warmer) feed to the cold box (e.g., a multi-stream heat exchanger) and then optionally at least a portion thereof can be recovered as a Warm HP Flash Gas product stream. In some embodiments, the first CO2-depleted flash gas still comprises at least 5 mole% CO2 (e.g., at least 7 mole% CO2, at least 10 mole% CO2, at least 15 mole% CO2, or at least 20 mole% CO2). For example, the first CCh-depleted flash gas may comprise from 5 mole% CO2 to 20 mole% CO2, from 7 mole% CO2 to 20 mole% CO2, or from 10 mole% CO2 to 20 mole% CO2. In some embodiments, the first CO2-depleted flash gas also comprises CO, CH4, N2, Ar, H2, He, Ar, or any combinations thereof. In some embodiments, the first CO2-depleted flash gas comprises at least 5 mole% H2 (e.g., at least 7 mole% H2, at least 10 mole% H2, at least 15 mole% H2, or atleast 20 mole% H2). For example, the first CO2-depleted flash gas may comprise from 5 mole% H2 to 20 mole% H2, from 7 mole% H2 to 20 mole% H2, or from 10 mole% H2 to 20 mole% H2.

[0044] In some embodiments, at least a portion of the first CO2-depleted flash gas (warm HP flash gas) is recycled back to the hydrogen manufacturing unit or step. The warm HP flash gas can be near ambient temperature, i.e. at a temperature of around 5 °C, or around 15 °C, or around 25 °C, or around 35 °C, or from 5 °C to 35 °C. This makes the warm HP flash gas a suitable candidate for cooling adsorbers at higher temperatures, such as in the range of 100 °C to 300 °C. In some of these cases, the first CO2-depleted flash gas can undergo a reforming reaction, converting its residual CH4 content into additional H2 and CO by reforming with CO2 and steam in a catalytic reactor or reformer. The reformer can be of the heat-exchanger and / or gas-heated reformer-type, for example. In other embodiments, the first CO2-depleted flash gas can be combined with fresh hydrocarbon feed and fed to another reformer part of the same hydrogen manufacturing unit or step (e.g., a pre-reformer, a steam-methane reformer (SMR), autothermal reformer (ATR), or any combination thereof).

[0045] In some embodiments, at least a portion of the first CO2-depleted flash gas (warm HP flash gas) is heated with heat from the hydrogen manufacturing unit (e.g., before or during reforming) to generate a hot HP flash gas. In some embodiments, the hot HP flash gas can be used to heat the dryer (e.g., temperature swing adsorption-based (TSA) dryer) during the heating step. This can facilitate the desorption of the adsorbed water from the TSA dryer adsorbent and allow recovery of the desorbed water for further steam reforming reactions when the water-loaded hot HP flash gas reaches the reforming section of the hydrogen manufacturing unit. After completion of the dryer heating step, in some embodiments, a remaining portion of the first CO2-depleted flash gas (warm HP flash gas) can be used as a coolant (e.g., to return the TSA dryer bed back to ambient conditions to start a new drying phase, thereby recovering some of the heat that was delivered to the TSA dryer bed).

[0046] Heating at least a portion of the first CO2-depleted flash gas (warm HP flash gas) with heat from the hydrogen manufacturing unit as described in the embodiments above can provide multiple advantages for the performance of the hydrogenmanufacturing unit. Some of these advantages can include: (1) heat recovery from the hydrogen manufacturing unit to regenerate the dryer can eliminate the need for the installation of a stand-alone regeneration gas heater; (2) water recovery from the dryer bed in the heating step can reuse the water as a reactant in the reforming reactions; (3) water recovery from the dryer can also eliminate the need for a spent regeneration gas cooler and knock-out drum; (4) the residual water content from the spent regeneration gas is not recycled to the inlet of the dryer and the dryer size might therefore be reduced; (5) additional hydrogen generation from the recovered water and methane molecules.

[0047] Thus, in some embodiments, the recycle of the hot HP flash gas (or warm HP flash gas if not heated by the hydrogen manufacturing unit) to the reform er / reformi ng step can involve: (1) the hot HP flash gas recycle stream is mixed with the steam / hydrocarbon mixture and fed to a main reformer (SMR or ATR, or a combination thereof, either in series or in parallel); (2) the hot HP flash gas recycle stream is mixed with the steam / hydrocarbon mixture and fed to a pre-reformer; (3) the hot HP flash gas recycle stream is mixed with make-up steam and / or make-up hydrocarbons to the tube side inlet of a heat-exchanger reformer installed in parallel to the main reformer that receives its shell side heat input from the mixture of the main reformer outlet and the tube side outlet to generate a reformed gas that is sent to the water gas shift section of the hydrogen manufacturing unit; (4) the hot HP flash gas recycle stream is mixed with makeup steam and / or make-up hydrocarbons to the tube side inlet of a gas-heated reformer installed in series to the main reformer that receives its shell side heat input from the main reformer outlet, generating a partially reformed stream that is mixed with the feed hydrocarbon / steam mixture and fed to the main reformer from the tube side outlet, and a fully reformed stream from the shell side outlet is sent to the water gas shift section of the hydrogen manufacturing unit; and combinations thereof.

[0048] In some embodiments, at least a portion of the first CCh-depleted flash gas is fed to an additional CO2 recovery unit (e.g., a solvent absorption unit, a membrane, a PSA system, or any combinations thereof) where at least some of the remaining CO2 is separated from the stream (e.g., the rest of the gases) and recycled to the compressor / compression stage. In some embodiments, the remaining stream / gases can be recovered and / or used as fuel.

[0049] In some embodiments, at least a portion of the first CCh-depleted flash gas is recycled to the H2 PSA unit.

[0050] In some embodiments, at least a portion of the first CO2-depleted flash gas is recycled to the compressor / compression stage (e.g., at least 10 mole%, at least 20 mole%, at least 30 mole%, at least 40 mole%, at least 50 mole%, at least 60 mole%, at least 70 mole%, at least 80 mole%, at least 90 mole%, or 100 mole% recycled to the compression stage).

[0051] In some embodiments, the CO2-rich condensate separated from the first CO2-depleted flash gas has sufficient purity and can be used as a product stream. However, in most embodiments, the CO2-rich condensate is subjected to a further cryogenic purification. Also, in some embodiments, the above-described stages of cooling, condensing, and separating can be repeated (e.g., repeated one time, repeated two times, or repeated three times) to produce a further enriched CO2-rich condensate (e.g., from multiple CO2-rich condensates).

[0052] In some embodiments, the separated CO2-rich condensate (or collection of multiple condensates, in embodiments that involve multiple cycles of cooling-condensing-separation) is optionally reheated in a heat exchanger (e.g., the first heat exchanger or the cold box). In some embodiments, the optionally reheated separated CO2-rich condensate(s) can then be expanded to a lower pressure, which allows further cooling (e.g., cooling to temperature above - 56 °C, (a temperature below which there is a risk of CO2 freezing)). The cooled CO2-rich stream can, in some embodiments, be partially evaporated (e.g., in an evaporator) and separated (e.g., in a phase separator) into at least one vapor phase and at least one liquid phase. In some embodiments, the generated vapor phase (first LP flash gas) is separated from the liquid phase (second CO2-rich condensate) in a second phase separator without additional hot or cold energy supplied. However, in some embodiments, additional hot or cold energy can be used. The second CO2-rich condensate is recovered as CO2 product. In some embodiments the second CO2-rich condensate is recovered as CO2 product without any refrigeration recovered from the condensate. Optionally, this CO2 product can be pumped as liquid to a desired export pressure. In some embodiments, after or without pumping, this CO2 product can be heated to partially cool down the dried gas stream, while remaining in liquid phase. Insome embodiments, this CO2 product can (also) be used to cool down the feed to the Temperature Swing Adsorption Dryer unit.Cryogenic Distillation

[0053] In some embodiments where the purity of the second CO2-rich condensate is insufficient, the second CO2-rich condensate can be directed to a distillation column. In the distillation, the bottom is heated and at least partially vaporized in a reboiler, generating vapor circulation, for example. In some embodiments, no condenser for the partial (or full) condensation of the vapor product is utilized. Without a condenser, the entire cold overhead stream (second LP flash gas) from the column can, in some cases, be used as refrigerant for the incoming feed gas instead of (or in addition to) requiring refrigeration duty. However, some embodiments use a condenser for partial or full condensation of the vapor product. In some embodiments, the reboiler duty is supplied by the warm feed gas and can be integrated within the aforementioned cold box (multistream heat exchanger). In some embodiments, the liquid column product can either be extracted as final CO2 product or in some other embodiments can be pumped and exported, or pumped, heated, and then exported as a liquid product.

[0054] In some embodiments, at least a portion of the first LP flash gas, at least a portion of the second LP flash gas, or any combination of at least a portion of both, can be used to cool down the warm dried gas feed. In some embodiments, at least a portion of the first LP flash gas, at least a portion of the second LP flash gas, or any combination of at least a portion of both can be fully or partially recycled to the feed and / or an interstage of the multistage compressor after heating.

[0055] In some embodiments, at least a portion of the first LP flash gas, at least a portion of the second LP flash gas, or any combination of at least a portion of both, can be used as regeneration gas for the Temperature Swing Adsorption Dryer.Recovery of Light Gases

[0056] The HP flash gas and LP flash gas (e.g., first LP flash gas, second LP flash gas, third LP flash gas, etc) streams generated by different embodiments can be treated in different ways. For example, in some embodiments requiring only a moderate CO2product purity, the bottom purification step can be omitted. However, if downstream operations require an improved CO2 purity, the bottom purification section can be included. For systems requiring a moderate CO2 capture rate (e.g., 60 to 90 % of incoming CO2 or 80 to 85 % of incoming CO2,), the HP flash gas can be sent to the battery limit and used as fuel, for example. In embodiments where a higher CO2 capture rate is required by downstream operations (e.g., above 80 % of incoming CO2, above 85 % of incoming CO2, above 90 % of incoming CO2, above 95 % of incoming CO2, above 98 % of incoming CO2, from 85 % to 99.99 % of incoming CO2), the LP flash gas recycle and / or the HP flash gas recycle options can optionally be implemented, increasing the overall CO2 capture rate (e.g., to above 80 % of incoming CO2, above 85 % of incoming CO2, above 90 % of incoming CO2, above 95 % of incoming CO2, above 98 % of incoming CO2, from 90 % to 93 % of incoming CO2, or from 85 % to 99.5 % of incoming CO2), by the addition of the recycle compression equipment. Further extension with additional purification and / or recovery units on the HP flash gas and / or LP flash gas streams can be considered when even higher CO2 capture rates (e.g., above 90 % of incoming CO2, above 93 % of incoming CO2, above 95 % of incoming CO2, above 97 % of incoming CO2, above 98 % of incoming CO2, from 93.% to 99.5 % of incoming CO2, or from 95 % to 99.9 % of incoming CO2), are desired in certain embodiments. Thus, the disclosed system can be modularly constructed and expanded as desired CO2 capture requirements change and evolve over time.CO2 Removal Systems and Process Examples

[0057] These illustrative examples are given to introduce the reader to the general subject matter discussed here and are not intended to limit the scope of the disclosed concepts. The following sections describe various additional features and examples with reference to the drawings in which like numerals indicate like elements but, like the illustrative examples, should not be used to limit the present disclosure. In all of the following, a same reference designates a stream flowing in a conduit and the conduit which conveys this stream.

[0058] FIG. 1 illustrates some embodiments of the disclosure. In FIG. 1, a shifted syngas stream 1 from a hydrogen manufacturing unit or step is directed to a H2 PressureSwing Adsorption (PSA) unit 2. As shown in FIG. 1 , the PSA unit 2 can generate at least two product streams: a first product stream 3 recovered at high pressure (e.g., close to the PSA feed inlet pressure) comprising most of the H2 and substantially no CO2 (e.g., only a small amount), and a CO2-rich second product stream 4 recovered at low pressure that comprises the remaining components (e.g., CO2, and at least one of CO, CH4, N2, Ar, H2, or H2O).

[0059] The CO2-rich second product stream 4 is compressed to higher pressure in at least one compressor 10 to produce a compressed feed stream 15. In some embodiments, the compression can take place in a multistage compressor with intercooling.

[0060] The compressed feed stream 15 can be chilled in a first heat exchanger 20 (e.g., chilled by cold streams available from the cold process described below) to produce chilled compressed feed stream 25. The chilled compressed feed stream 25 can be dried in a dryer 30 (e.g., a temperature swing adsorption dryer) to produce a dried feed stream 35. As such, residual water in the feed stream 4 that is not liquified in the compression process or the first heat exchanger 20 (and removed by a knock-out drum upstream of the dryer (not shown in FIG. 1)) can be removed by the dryer 30, for example.

[0061] Following the drying, in some embodiments the dried stream 35 can be fed to a cold box (multi-stream heat exchanger) 40. The dried stream 35 is at least partially cooled using a refrigeration package 200 in one or more passes through the cold box 40 to produce a partially condensed mixed phase stream 45, with the condensate enriched in CO2. In some embodiments, because water has been removed by the dryer, the condensate will comprise primarily CO2 (e.g., more than 50 mole% CO2, more than 60 mole% CO2, more than 70 mole% CO2, more than 80 mole% CO2, or more than 90 mole% CO2,) and optionally containing some dissolved light gases (including CF , CO, N2, Ar, He, O2, and combinations thereof).

[0062] In some embodiments, the CO2-rich condensate of the partially condensed stream 45 can be separated from the vapor phase in a phase separator 50, producing a first CO2-rich liquid 55, and a first CO2-depleted flash gas 52 (HP flash gas). In some embodiments, the first CO2-depleted flash gas 52 can be used to at least partially cooldown the (warmer) dried stream feed 35 to the cold box 40 and then optionally recovered as a warm HP Flash Gas product stream 57.

[0063] In some embodiments not shown in FIG. 1, the above-described stages of cooling, condensing, and separating can be repeated (e.g., repeated one time, repeated two times, or repeated three times) to produce a further enriched CO2-rich condensate (e.g., from multiple CO2-rich condensates).

[0064] In some embodiments, the separated CO2-rich liquid condensate 55 (or collection of multiple condensates, in embodiments (not shown) that involve multiple cycles of cooling-condensing-separation) is optionally reheated in a heat exchanger (not shown), and expanded to a lower pressure with expansion device 60 (e.g., a valve) to produce a lower pressure CO2-rich liquid condensate 65, which can be further cooled in some embodiments (not shown). The lower pressure CO2-rich liquid condensate 65 can be partially evaporated and separated in a second phase separator 70 into at least one vapor phase 72 and at least one liquid phase 75. In some embodiments, the generated vapor phase 72 (first LP flash gas) is separated from the liquid phase 75 (second CO2-rich condensate) in the second phase separator 70 without additional hot or cold energy supplied. The generated vapor phase 72 (first LP flash gas) can (also) be used to at least partially cool down the (warmer) dried stream feed 35 to the cold box 40 and then optionally recovered as a product stream 73. Optionally, the liquid phase 75 (second CO2-rich condensate) can be pumped in at least one pump 80 as liquid to a desired CO2 product pressure. The pumped CO2 product 85 can be used to cool down the compressed feed stream 15 before the temperature swing adsorption dryer unit 30 in the first heat exchanger 20 and then recovered as CO2 product stream 100. In some embodiments not shown in FIG. 1 , after or without pumping, the CO2 stream 85 can be heated to partially cool down the dried gas stream 35, while remaining in liquid phase. In some embodiments also not shown in FIG. 1, the second CO2-rich condensate 75 (or 85) is recovered as CO2 product without any refrigeration recovered from the condensate.

[0065] In some embodiments not shown in FIG. 1 , at least a portion of the first LP flash gas and / or at least a portion of the HP flash gas, can be used as a cold regeneration gas for a cooling step of the regeneration of the temperature swing adsorption dryer, recovering heat from a hot adsorber bed.

[0066] FIG. 2 illustrates some additional embodiments of the disclosure that include recycle options. In FIG. 2, a shifted syngas stream 1 from a hydrogen manufacturing unit or step is again directed to a H2 Pressure Swing Adsorption (PSA) unit 2 to generate at least two product streams: a first product stream 3 recovered at high pressure (e.g., close to the PSA feed inlet pressure) comprising most of the H2 and substantially no CO2 (e.g., only a small amount), and a CO2-rich second product stream 4 recovered at low pressure that comprises the remaining components (e.g., CO2, and at least one of CO, CF , N2, Ar, H2, or H2O).

[0067] The CO2-rich second product stream 4 is compressed to higher pressure in at least one compressor 10 (e.g., a single compressor or a multistage compressor with intercooling) to produce a compressed feed stream 15.

[0068] The compressed feed stream 15 can be chilled in a first heat exchanger 20 (e.g., chilled by cold streams available from the cold process described below) to produce chilled compressed feed stream 25. The chilled compressed feed stream 25 can be dried in a dryer 30 (e.g., a temperature swing adsorption dryer) to produce a dried feed stream 35. As such, residual water in the feed stream 4 that is not liquified in the compression process or the first heat exchanger 20 can be removed by the dryer 30, for example.

[0069] Following the drying, the dried stream 35 can be fed to a cold box (e.g., a multi-stream heat exchanger) 40. The dried stream 35 is at least partially cooled using a refrigeration package 200 in one or more passes through the cold box 40 to produce a partially condensed mixed phase stream 45, with the condensate enriched in CO2.

[0070] In some embodiments, the CO2-rich condensate of the partially condensed stream 45 can be separated from the vapor phase in a phase separator 50, producing a first CO2-rich liquid 55, and a first CO2-depleted flash gas 52 (HP flash gas). In some embodiments, the first CO2-depleted flash gas 52 (HP flash gas) can be used to at least partially cool down the (warmer) dried stream feed 35 to the cold box 40 to form a warmed first CO2-depleted HP flash gas 57 stream. As shown in FIG. 2, this warmed first CO2-depleted HP flash gas 57 stream can be at least partially (e.g., at least 10 %, at least 20 %, at least 30 %, at least 40 %, at least 50 %, at least 60 %, at least 70 %, at least 80 %, at least 90 %, or at least 95 %) recycled back to the hydrogen manufacturing unit or stepas warm HP flash gas stream 53 or used as fuel, with the remainder of the warm HP flash gas stream 56 recycled to an inlet of the PSA unit 1.

[0071] In some embodiments not shown in FIG. 2, the above-described stages of cooling, condensing, and separating can be repeated (e.g., repeated one time, repeated two times, or repeated three times) to produce a further enriched CO2-rich condensate (e.g., from multiple CO2-rich condensates).

[0072] In some embodiments, the separated CO2-rich liquid condensate 55 (or collection of multiple condensates, in embodiments (not shown) that involve multiple cycles of cooling-condensing-separation) is optionally reheated in a heat exchanger (not shown), and expanded to a lower pressure with expansion device 60 to produce a lower pressure CO2-rich liquid condensate 65, which can be further cooled in some embodiments (not shown). The lower pressure CO2-rich liquid condensate 65 can be partially evaporated and separated in a second phase separator 70 into at least one vapor phase 72 and at least one liquid phase 75. In some embodiments, the generated vapor phase 72 (first LP flash gas) is separated from the liquid phase 75 (second CO2-rich condensate) in the second phase separator 70 without additional hot or cold energy supplied. The generated vapor phase 72 (first LP flash gas) can (also) be used to at least partially cool down the (warmer) dried stream feed 35 to the cold box 40 and then at least partially recycled as a warmed stream 73 back to the compressor 10. Optionally, the liquid phase 75 (second CO2-rich condensate) can be pumped in at least one pump 80 as liquid to a desired CO2 product pressure. The pumped CO2 product 85 can be used to cool down the compressed feed stream 15 before the temperature swing adsorption dryer unit 30 in the first heat exchanger 20 and then recovered as CO2 product stream 100. In some embodiments not shown in FIG. 2, after or without pumping, the CO2 stream 85 can be heated to partially cool down the dried gas stream 35, while remaining in liquid phase. In some embodiments also not shown in FIG. 2, the second CO2-rich condensate 75 (or 85) is recovered as CO2 product without any refrigeration recovered from the condensate.

[0073] FIG. 3 illustrates some additional embodiments of a disclosure that includes a recycle option with additional CO2 recovery from the flash gas. In comparison to the process described in FIG. 2, at least a portion (56) of the remainder of the warmed firstC02-depleted flash gas 57 can be fed to an additional CO2 recovery unit 48 (e.g., a solvent absorption unit, a membrane, a PSA system, or any combinations thereof) where at least some of the remaining CO2 is separated from the stream (e.g., the rest of the gases) and recycled as recycle stream 51 to the feed to the compressor / compression stage 4 (CO2-rich second product stream) to form combined feed stream 7 to the compressor 10. In some embodiments, the remaining stream / gases 54 can be recovered and / or used as fuel.

[0074] In some embodiments not shown in FIG. 3, the above-described stages of cooling, condensing, and separating can be repeated (e.g., repeated one time, repeated two times, or repeated three times) to produce a further enriched CO2-rich condensate (e.g., from multiple CO2-rich condensates).

[0075] In some embodiments, the separated CO2-rich liquid condensate 55 (or collection of multiple condensates, in embodiments (not shown) that involve multiple cycles of cooling-condensing-separation) is optionally reheated in a heat exchanger (not shown), and expanded to a lower pressure with expansion device 60 to produce a lower pressure CO2-rich liquid condensate 65, which can be further cooled in some embodiments (not shown). The lower pressure CO2-rich liquid condensate 65 can be partially evaporated and separated in a second phase separator 70 into at least one vapor phase 72 and at least one liquid phase 75. In some embodiments, the generated vapor phase 72 (first LP flash gas) is separated from the liquid phase 75 (second CO2-rich condensate) in the second phase separator 70 without additional hot or cold energy supplied. The generated vapor phase 72 (first LP flash gas) can (also) be used to at least partially cool down the (warmer) dried stream feed 35 to the cold box 40 and then at least partially recycled as a warmed stream 73 back to the compressor 10. Optionally, the liquid phase 75 (second CO2-rich condensate) can be pumped in at least one pump 80 as liquid to a desired CO2 product pressure. The pumped CO2 product 85 can be used to cool down the compressed feed stream 15 before the temperature swing adsorption dryer unit 30 in the first heat exchanger 20 and then recovered as CO2 product stream 100. In some embodiments not shown in FIG. 3, after or without pumping, the CO2 stream 85 can be heated to partially cool down the dried gas stream 35, while remaining in liquid phase. In some embodiments also not shown in FIG. 3, the second CO2-rich condensate75 (or 85) is recovered as CO2 product without any refrigeration recovered from the condensate.

[0076] FIG. 4 illustrates some additional embodiments of the disclosure that include recycle options and additional bottom purification. In FIG. 4, a shifted syngas stream 1 from a hydrogen manufacturing unit or step is again directed to a H2 Pressure Swing Adsorption (PSA) unit 2 to generate at least two product streams: a first product stream 3 recovered at high pressure (e.g., close to the PSA feed inlet pressure) comprising most of the H2 and substantially no CO2 (e.g., only a small amount), and a CO2-rich second product stream 4 recovered at low pressure that comprises the remaining components (e.g., CO2, and at least one of CO, CF , N2, Ar, H2, or H2O).

[0077] The CO2-rich second product stream 4 is compressed to higher pressure in at least one compressor 10 (e.g., a single compressor or a multistage compressor with intercooling) to produce a compressed feed stream 15.

[0078] The compressed feed stream 15 can be chilled in a first heat exchanger 20 (e.g., chilled by cold streams available from the cold process described below) to produce chilled compressed feed stream 25. The chilled compressed feed stream 25 can be dried in a dryer 30 (e.g., a temperature swing adsorption dryer) to produce a dried feed stream 35. As such, residual water in the feed stream 4 that is not liquified in the compressor 10 or the first heat exchanger 20 can be removed by the dryer 30, for example.

[0079] Following the drying, the dried stream 35 can be fed to a cold box (e.g., a multi-stream heat exchanger) 40. The dried stream 35 is at least partially cooled using a refrigeration package 200 in one or more passes through the cold box 40 to produce a partially condensed mixed phase stream 45, with the condensate enriched in CO2.

[0080] In some embodiments, the partially condensed mixed phase stream 45 can be expanded to a lower pressure with expansion device 120 to produce a lower pressure mixed phase stream 47. The CO2-rich condensate of the mixed phase stream 47 can be separated from the vapor phase in a phase separator 50, producing a first CO2-rich liquid 55, and a first CO2-depleted flash gas 52 (HP flash gas). In some embodiments, the first CO2-depleted flash gas 52 (HP flash gas) can be used to at least partially cool down the (warmer) dried stream feed 35 to the cold box 40 to form a warmed first CO2-depleted flash gas 57 (HP flash gas) stream. As shown in FIG. 4, this warmed first CO2-depletedflash gas 57 (HP flash gas) stream can be at least partially (53) (e.g., at least 10 %, at least 20 %, at least 30 %, at least 40 %, at least 50 %, at least 60 %, at least 70 %, at least 80 %, at least 90 %, or 100 %) recycled back to the hydrogen manufacturing unit or step. In addition, at least a portion (56) of the remainder of the warmed first CCh-depleted flash gas 57 can be fed to an additional CO2 recovery unit 48 (e.g., a solvent absorption unit, a membrane, a PSA system, or any combinations thereof) where at least some of the remaining CO2 is separated from the stream (e.g., the rest of the gases) and recycled as recycle stream 51 to the feed to the compressor / compression stage 4 (CO2-rich second product stream) to form combined feed stream 7 to the compressor 10. In some embodiments, the remaining stream / gases 54 can be recovered and / or used as fuel.

[0081] In some embodiments not shown in FIG. 4, the above-described stages of cooling, condensing, and separating can be repeated (e.g., repeated one time, repeated two times, or repeated three times) to produce a further enriched CO2-rich condensate (e.g., from multiple CO2-rich condensates).

[0082] In some embodiments, the separated CO2-rich liquid condensate 55 (or collection of multiple condensates, in embodiments (not shown) that involve multiple cycles of cooling-condensing-separation) is optionally reheated in a heat exchanger (not shown), and expanded to a lower pressure with expansion device 60 to produce a lower pressure CO2-rich liquid condensate 65, which can be further cooled in some embodiments (not shown). The lower pressure CO2-rich liquid condensate 65 can be partially evaporated and separated in a second phase separator 70 into at least one vapor phase 72 and at least one liquid phase 75. In some embodiments, the generated vapor phase 72 (first LP flash gas) is separated from the liquid phase 75 (second CO2-rich condensate) in the second phase separator 70 without additional hot or cold energy supplied. The generated vapor phase 72 (first LP flash gas) can (also) be used to at least partially cool down the (warmer) dried stream feed 35 to the cold box 40 and then at least partially recycled as a warmed stream 73 back to the compressor 10.

[0083] As shown in FIG. 4, the liquid phase 75 (second CO2-rich condensate) can be directed to a distillation column 150 for further purification. In the distillation column 150, the bottoms is heated and at least partially vaporized in a reboiler 160, generating vapor recirculation stream 162, for example. The overhead stream 152 (second LP flashgas) from the distillation column 150 and the generated vapor phase 72 (first LP flash gas) from the second phase separator 70 can, either separately or combined, be used to at least partially cool down the (warmer) dried stream feed 35 to the cold box 40 and then at least partially recycled as a warmed stream 73 back to the compressor 10. In some embodiments, no condenser for the partial (or full) condensation of the vapor product is utilized in the column 150. In some embodiments not shown in FIG. 4, without a condenser, the entire overhead stream 152 (second LP flash gas) from the column 150 can, in some cases, be used as refrigerant for the incoming feed gas instead of (or in addition to) requiring refrigeration duty. However, some embodiments also not shown in FIG. 4 use a condenser with the column for partial or full condensation of the vapor product. In some embodiments, the reboiler 160 duty can be at least partially supplied by integration with the cold box 40 and related streams. Thus, as shown in FIG. 4, at least a portion 49 of the partially condensed mixed phase stream 45 from the cold box 40 can be used to provide at least some of the reboiler 160 duty and then returned as cooled stream 46 bypassing expansion device 120 and be fed to the first phase separator 50. In some embodiments at least a portion 36 of the (warmer) dried stream feed 35 can (also or instead) be used to provide at least some of the reboiler duty, bypassing the cold box as shown in FIG. 4. In some embodiments, the liquid column product 77 can be pumped in at least one pump 80 as liquid to a desired CO2 product pressure. The pumped CO2 product 85 can be used to cool down the compressed feed stream 15 before the temperature swing adsorption dryer unit 30 in the first heat exchanger 20 and then recovered as CO2 product stream 100. In some embodiments not shown in FIG. 4, after or without pumping, the CO2 stream 85 can be heated to partially cool down the dried gas stream 35, while remaining in liquid phase. In some embodiments also not shown in FIG.4, the second CO2-rich condensate 75 (or 85) is recovered as CO2 product without any refrigeration recovered from the condensate.

[0084] The described processes and systems can be used in any field where there is a need for CO2 removal from a process stream. The disclosure aims to reduce the carbon footprint, and potentially increase the efficiency, of CO2 removal and / or capture. Some of the benefits of the invention can include a reduction of carbon dioxide emissions, for example from 5 to 99 % (e.g., 80 % to 98 % or from 85 % to 95 %) reduction of allcarbon contained in a stream (feed gas). In addition, the described processes and systems can achieve improved efficiencies, such as the use of significantly less external refrigerant and less unit operations and equipment. The described processes and systems can also be modular and have a phased implementation, delivering an advantage for retrofitting existing systems and plants, tailoring the required investment to the targeted CO2 capture rate while still allowing room for future improvement.Integrated Refrigeration Systems and Processes

[0085] FIG. 5 illustrates some additional embodiments of the refrigeration circuit 200 of the disclosure. Mixed refrigerant 205 is fed to condenser 210 with heat exchanger 211 and condensed at a high pressure to produce a condensed refrigerant stream 215. In some embodiments, the condenser 210 can be air-cooled or water-cooled. The condensed refrigerant stream 215 can be further subcooled in the cold box 40 to produce a subcooled condensed refrigerant stream 217. A first portion of the subcooled condensed refrigerant stream 217 can be expanded to a first low pressure with expansion device 220 to produce a mixed phase stream 225 having a sharp temperature decrease to below the (partial) condensation temperature of the warm dried feed gas 35. At least one additional portion of the subcooled condensed refrigerant stream 217 can be expanded to a second low pressure (e.g., lower than the first low pressure) with expansion device 221 to produce a mixed phase stream 226 at a temperature below the (partial) condensation temperature of the warm dried feed gas 35. In some embodiments not shown in FIG. 5, other portions of the subcooled condensed refrigerant stream 217 can be expanded to different lower pressures (ranging from the lowest pressure to the highest pressure) using expansion devices to produce mixed phase streams at temperatures below the (partial) condensation temperature of the warm dried feed gas 35. In some embodiments, at least one portion of the subcooled condensed refrigerant stream 217 can be expanded to a low pressure to produce a mixed phase stream at a temperature below the (partial) condensation temperature of the warm dried feed gas 35 and is used for cooling, while the other portions of the subcooled condensed refrigerant stream 217 do not (necessarily) achieve a temperature below the (partial) condensation temperature of the warm dried feed gas 35. The mixed phase streams 225 and 226 can then be fullyevaporated against the warm dried feed gas 35 at low pressure in the cold box 40 to produce evaporated streams 227 and 228, respectively. The evaporated stream 228 is then compressed to higher pressure in a compressor (stage) 231 to produce a compressed stream 229 that can be combined with higher pressure evaporated stream 227 with the combined stream compressed in a second compressor (stage) 230 to produce a further compressed stream 233 which can, in some embodiments, be the high pressure of the system. In the embodiments not shown in FIG. 5 that use multiple portions of the condensed refrigerant stream, the compression and combinations steps are repeated until all portions are combined and compressed to the high system pressure. The further compressed stream 233 is cooled back to the condensation temperature in a heat exchanger 240 and returned to the condenser 210 to complete the loop. Streams 57 and 100 exiting and stream 15 entering the system of FIG. 5 can be understood as streams with the same numbers in other embodiments .

[0086] FIG. 6 illustrates some additional embodiments of the refrigeration circuit 200 of the disclosure. Mixed refrigerant 205 is fed to condenser 210 with heat exchanger 211 and condensed at a high pressure to produce a condensed refrigerant stream 215. In some embodiments, the condenser 210 can be air-cooled or water-cooled. A first portion of the condensed refrigerant stream 215 can be further subcooled by cold vapor gases (HP flash gas and / or LP flash gas) from the cold box 40 (first multi-stream heat exchanger) to produce a first subcooled condensed refrigerant stream 217. A second portion of the condensed refrigerant stream 215 is subcooled in a second multi-stream heat exchanger 250 against evaporating refrigerant to produce a second subcooled condensed refrigerant stream 255. A third portion of the condensed refrigerant stream 215, which is shown as part of the second portion, is even further subcooled in a third multi-stream heat exchanger 280 against evaporating refrigerant to form a third subcooled condensed refrigerant stream 285. Warm dried feed gas 35 is cooled (and optionally partially condensed) in the second multi-stream heat exchanger 250 and third multistream heat exchanger 280 sequentially. The first subcooled condensed refrigerant stream 217 is expanded to a first low pressure by expansion device 220 to produce a mixed phase stream 225 having a sharp temperature decrease to below the (partial) condensation temperature of the warm dried feed gas 35. The third subcooledcondensed refrigerant stream 285 is expanded by expansion device 290 to the same first low pressure as mixed phase stream 225 and then combined with mixed phase stream 225 to produce a combined stream 292. The combined stream 292 is fully evaporated against the dried feed gas 35 in the third multi-stream heat exchanger 280 to produce a combined evaporated stream 293. The second subcooled condensed refrigerant stream 255 is expanded to a second low pressure (e.g. lower than the first low pressure) by expansion device 260 to produce a second mixed phase stream 265 having a sharp temperature decrease to below the (partial) condensation temperature of the warm dried feed gas 35. In some embodiments, at least one portion of the subcooled condensed refrigerant stream 255 can be expanded to a low pressure to produce a mixed phase stream at a temperature below the (partial) condensation temperature of the warm dried feed gas 35 and is used for cooling, while the other portions of the subcooled condensed refrigerant stream do not (necessarily) achieve a temperature below the (partial) condensation temperature of the warm dried feed gas 35. The second mixed phase stream 265 is fully evaporated against the dried feed gas 35 in the second multi-stream heat exchanger 250 to produce an evaporated stream 267. The combined evaporated stream 293 is compressed in a first compressor (stage) 231 to the second low pressure and mixed with the evaporated stream 267 to form a recombined stream 268. The recombined stream 268 is compressed by a second compressor (stage) 230 to produce a further compressed stream 233 which can, in some embodiments, be at the high pressure of the system. In embodiments not shown in FIG. 6 that use multiple portions of the condensed refrigerant stream, the compression and combinations steps are repeated until all portions are combined and compressed to the high system pressure. The further compressed stream 233 is cooled back to the condensation temperature in a heat exchanger 240 and returned to the condenser 210 to complete the loop. Additionally, where a distillation column 150 is used in the disclosed process, the column reboiler 160 can be integrated with the feed to the third multi-stream heat exchanger 280, bypassing the third multi-stream heat exchanger 280 as shown in FIG. 6, the cold box 40, the second multi-stream heat exchanger 250, the third multi-stream heat exchanger 280, or any combinations thereof, for example. Streams 57 and 100 exiting and stream 15 entering the system of FIG. 6 can be understood as the same streams in other embodiments.

[0087] FIG. 7 illustrates some additional embodiments of the refrigeration circuit 200 of the disclosure. Mixed refrigerant 205 is fed to condenser 210 with heat exchanger 211 and condensed at a high pressure to produce a condensed refrigerant stream 215. In some embodiments, the condenser 210 can be air-cooled or water-cooled. A first portion of the condensed refrigerant stream 215 can be further subcooled by cold vapor gases (HP flash gas and / or LP flash gas) from the cold box 40 (first multi-stream heat exchanger) to produce a first subcooled condensed refrigerant stream 217. A second portion of the condensed refrigerant stream 215 is subcooled in a second multi-stream heat exchanger 250 against evaporating refrigerant to produce a second subcooled condensed refrigerant stream 255. A third portion of the condensed refrigerant stream 215, which is shown as part of the second subcooled condensed refrigerant stream 255, is even further subcooled in a third multi-stream heat exchanger 280 against evaporating refrigerant to form a third subcooled condensed refrigerant stream 285. Warm dried feed gas 35 is cooled (and optionally partially condensed) in the second multi-stream heat exchanger 250 and third multi-stream heat exchanger 280 sequentially.

[0088] A portion of first subcooled condensed refrigerant stream 217 is expanded to a first low pressure by expansion device 220 to produce a mixed phase stream 225 having a sharp temperature decrease to below the (partial) condensation temperature of the warm dried feed gas 35. The third subcooled condensed refrigerant stream 285 is expanded by expansion device 290 to the same first low pressure as mixed phase stream 225 and then combined with mixed phase stream 225 to produce a combined stream 292.

[0089] The remaining portion of first subcooled condensed refrigerant stream 217 is expanded to a second low pressure level (e.g. lower than the first low pressure) by expansion device 281 and heated in the third multi-stream heat exchanger 280 to produce a heated first refrigerant stream 282. The second subcooled condensed refrigerant stream 255 (that is not sent to the third multi-stream heat exchanger) is expanded to the second low pressure by expansion device 260 to produce a second mixed phase stream 265 having a sharp temperature decrease to below the (partial) condensation temperature of the warm dried feed gas 35. In some embodiments, at least one portion of the subcooled condensed refrigerant stream can be expanded to a low pressure to produce a mixed phase stream at a temperature below the (partial)condensation temperature of the warm dried feed gas 35 and is used for cooling, while the other portions of the subcooled condensed refrigerant stream do not (necessarily) achieve a temperature below the (partial) condensation temperature of the warm dried feed gas 35. The heated first refrigerant stream 282 and the second mixed phase stream 265 are combined and fully evaporated against the dried feed gas 35 in the second multistream heat exchanger 250 to produce an evaporated stream 266.

[0090] The combined stream 292 is fully evaporated against the dried feed gas 35 in the third multi-stream heat exchanger 280 to produce a combined evaporated stream 293. The combined evaporated stream 293 is compressed in a first compressor (stage) 231 to the second low pressure and mixed with the evaporated stream 266 to form a recombined stream 268. The recombined stream 268 is compressed by a second compressor (stage) 230 to produce a further compressed stream 233 which can, in some embodiments, be at the high pressure of the system. In embodiments not shown in FIG.7 that use multiple portions of the condensed refrigerant stream, the compression and combinations steps are repeated until all portions are combined and compressed to the high system pressure. The further compressed stream 233 is cooled back to the condensation temperature in a heat exchanger 240 and returned to the condenser 210 to complete the loop. Additionally, where a distillation column 150 is used in the disclosed process, the column reboiler 160 can be integrated with the feed to the third multi-stream heat exchanger 280, bypassing the third multi-stream heat exchanger 280 as shown in FIG. 7, the cold box 40, the second multi-stream heat exchanger 250, the third multistream heat exchanger 280, or any combinations thereof, for example. Streams 57 and 100 exiting and stream 15 entering the system of FIG. 7 can be interpreted as the streams with the same numbers in other embodiments.

[0091] FIG. 8 illustrates some additional embodiments of the refrigeration circuit 200 of the disclosure. Mixed refrigerant 205 is fed to condenser 210 with heat exchanger 211 and partially condensed at a high pressure to produce a first condensed refrigerant stream 215 and a non-condensed refrigerant stream 212. In some embodiments, the condenser 210 can be air-cooled or water-cooled. A first portion of the condensed refrigerant stream 215 can be further subcooled by cold vapor gases (HP flash gas and / or LP flash gas) from the cold box 40 (first multi-stream heat exchanger) to produce a firstsubcooled condensed refrigerant stream 217. A second portion of the first condensed refrigerant stream 215 is subcooled in a second multi-stream heat exchanger 250 against evaporating refrigerant to produce a second subcooled condensed refrigerant stream 255. A third portion of the first condensed refrigerant stream 215, which is shown as part of the second subcooled condensed refrigerant stream 255, is even further subcooled in a third multi-stream heat exchanger 280 against evaporating refrigerant to form a third subcooled condensed refrigerant stream 285. Warm dried feed gas 35 is cooled (and optionally partially condensed) in the second multi-stream heat exchanger 250 and third multi-stream heat exchanger 280 sequentially. The non-condensed refrigerant stream 212 is sequentially condensed and subcooled in the second multi-stream heat exchanger 250 and the third multi-stream heat exchanger 280 against evaporating refrigerant to produce a second condensed refrigerant stream 218. The second condensed refrigerant stream 218 is expanded in expansion device 270 to a first low pressure to produce an expanded stream 275. The expanded stream 275 is fed to a fourth multi-stream heat exchanger 300 to partially condense the first CO2-depleted flash gas 52 (HP flash gas) from the first phase separator 50 of the cryogenic system to produce a heated expanded stream 305. This partially condensed stream is separated in a third phase separator 310 of the cryogenic unit to produce a second HP flash gas 312 and a liquid condensate 317. The second HP flash gas 312 is heated sequentially in the fourth multi-stream heat exchanger 300 and the cold box 40 (first multi-stream heat exchanger) and exits the system as warmed HP flash gas 57. The liquid condensate 317 is expanded to the pressure of the second phase separator 70 by expansion device 318 and mixed with the second CO2-rich condensate 75 (liquid phase from second phase separator 70) and directed to either the distillation column 150 if present (as shown in FIG. 8) or the second phase separator 70.

[0092] At least a portion (full portion is shown in FIG. 8) of first subcooled condensed refrigerant stream 217 is expanded to approximately the same first low pressure by expansion device 220 to produce a mixed phase stream 225 having a sharp temperature decrease to below the (partial) condensation temperature of the warm dried feed gas 35. The third subcooled condensed refrigerant stream 285 is expanded by expansion device 290 to the same first low pressure as mixed phase stream 225 and thencombined with mixed phase stream 225 and heated expanded stream 305 (in any order) to produce a combined stream 292.

[0093] The second subcooled condensed refrigerant stream 255 (that is not sent to the third multi-stream heat exchanger 280) is expanded to a second low pressure (e.g. lower than the first low pressure) by expansion device 260 to produce a second mixed phase stream 265 having a sharp temperature decrease to below the (partial) condensation temperature of the warm dried feed gas 35. In some embodiments, at least one portion of the subcooled condensed refrigerant stream 255 can be expanded to a low pressure to produce a mixed phase stream at a temperature below the (partial) condensation temperature of the warm dried feed gas 35 and is used for cooling, while the other portions of the subcooled condensed refrigerant stream do not (necessarily) achieve a temperature below the (partial) condensation temperature of the warm dried feed gas 35. The second mixed phase stream 265 is evaporated (e.g., at least partially evaporated or fully evaporated) against the dried feed gas 35 in the second multi-stream heat exchanger 250 to produce an evaporated stream 266.

[0094] The combined stream 292 is evaporated (e.g., at least partially evaporated or fully evaporated) against the dried feed gas 35 in the third multi-stream heat exchanger 280 to produce a combined evaporated stream 293. The combined evaporated stream 293 is compressed in a first compressor (stage) 231 to the second low pressure and mixed with the evaporated stream 266 to form a recombined stream 268. The recombined stream 268 is compressed by a second compressor (stage) 230 to produce a further compressed stream 233 which can, in some embodiments, be at the high pressure of the system. In embodiments not shown in FIG. 8 that use multiple portions of the condensed refrigerant stream, the compression and combinations steps are repeated until all portions are combined and compressed to the high system pressure. The further compressed stream 233 is cooled back to the condensation temperature in a heat exchanger 240 and returned to the condenser 210 to complete the loop. Additionally, where a distillation column 150 is used in the disclosed process, the column reboiler 160 can be integrated with the feed to the third multi-stream heat exchanger 280, bypassing the third multi-stream heat exchanger 280 as shown in FIG. 8, the cold box 40, the secondmulti-stream heat exchanger 250, the third multi-stream heat exchanger 280, or any combinations thereof, for example.

[0095] In the embodiments related to FIG. 8, the column reboiler 160 output (where a distillation column 150 is used in the process) can be integrated with only the first phase separator 50 (e.g., the top of the first phase separator 50). Streams 57 and 100 exiting and stream 15 entering the system of FIG. 8 can be interpreted as the streams with the same numbers in other embodiments.Refrigerant

[0096] In some embodiments, the refrigerant can be any mixed refrigerant combination with two or more components, sufficient to cool down the dried feed stream 35 to temperatures below -35 °C. In some embodiments, the mixed refrigerant can be a light hydrocarbon and CO2 combination, such that condensation and evaporation condition requirements (e.g., temperature and pressure) are met.

[0097] Using CO2 as mixed refrigerant component in some embodiments can allow for lower requirements for external refrigerant consumption and storage, for example. While CO2 has been recognized as a refrigerant, CO2 is typically used in an open-loop refrigeration circuit. In such open-loop refrigeration circuits, at least a portion of a liquid CO2 product is constantly being evaporated (e.g., against a condensing feed stream) and then treated in a separate unit (liquefaction or compression) or recycled back to a cryogenic unit. For example, an initial amount of CO2 is used and starts circulating in the refrigerant loop going through the compression, condensation, expansion, and / or evaporation process in a closed circuit, and only a small make-up amount of CO2 might be used.Dryer Configurations

[0098] Depending on the layout of the temperature swing adsorption-based (TSA) dryer unit, different process schemes can be used in various embodiments. FIG. 9 shows embodiments of TSA dryer units with at least 2 adsorber vessels of which one is configured for successive adsorption and regeneration steps (phases). Only the adsorber vessel in regeneration 520 is shown in FIG. 9, as the other adsorber vessel(s) is (are) inthe drying step. The first C02-depleted flash gas (warm HP flash gas) 53 can be divided into a first portion 501 and a second portion 502. The first portion 501 of the first CO2-depleted flash gas and the second portion 502 of the first CO2-depleted flash gas may have substantially the same composition. Alternatively, or in addition, the first portion 501 of the first CO2-depleted flash gas and the second portion 502 of the first CO2-depleted flash gas may have substantially the same pressure. The first portion 501 of the first CO2-depleted flash gas (warm HP flash gas) 53 is heated in a heater 500 to produce a hot HP flash gas 505 of which at least a first portion is used as heating medium stream 506. In the present example, the heater 500 is a heater in the hydrogen manufacturing unit. The spent heating medium stream 507 from the adsorber vessel 520 and the remainder hot stream 508 (i.e. the remaining second portion 508 of the hot HP flash gas 505) can be recycled to the reformer / reforming section 510 for additional dry and steam reforming reactions. The first portion 506 of the hot HP flash gas and the second portion 508 of the hot HP flash gas may have substantially the same composition. During the heating step, the adsorber vessel in regeneration 520 can release the desorbed water into spent heating medium stream 507. The spent heating medium stream 507 can recycle the water as process steam to the reformer / reforming section 510. During this time, the remaining second portion of the warm HP flash gas 502 that is not used for heating the TSA dryer adsorber vessel in regeneration 520 can be recycled directly to the reforming section 510. When the heating phase is completed, a portion 502 (which can be the same or different than the portion recycled directly to the reforming section during the heating phase) of the warm HP flash gas 53 can first be used as a coolant, before optionally being mixed with the remainder portion 501 and then sent for heating in the heater 500 and being recycled to the reformer / reforming section 510 via bypass 508.

[0099] FIG. 10 shows embodiments of TSA dryer units with separate first and second adsorber vessels 520a and 520b configured for parallel heating and cooling steps (phases). The first CO2-depleted flash gas (warm HP flash gas) 53 can be divided into a first portion 501 and a second portion 502. The first portion 501 of the first CO2-depleted flash gas and the second portion 502 of the first CO2-depleted flash gas may have substantially the same composition. Alternatively, or in addition, the first portion 501 of the first CO2-depleted flash gas and the second portion 502 of the first CO2-depleted flashgas may have substantially the same pressure. The cooling step can use at least the second portion 502 of the first CO2-depleted flash gas (warm HP flash gas) 53 as a coolant for the first adsorber vessel 520a in cooling step. The spent coolant gas 521 from the first adsorber vessel 520a is heated in a heater 500 to produce a hot HP flash gas 505. The spent coolant gas 521 may be mixed back with the first portion 501 of the warm HP flash gas 53 and the resulting mixture may be heated in the heater to produce the hot HP flash gas 505. In the present example, the heater 500 is a heater in the hydrogen manufacturing unit. At least a first portion 506 of the hot HP flash gas is then used for heating the second adsorber vessel 520b in a heating step to produce a spent hot HP flash gas 507. The spent hot HP flash gas 507 can be combined with the second portion of the hot HP flash gas 508 and recycled to the reform er / reformi ng section 510. The first portion 506 of the hot HP flash gas and the second portion 508 of the hot HP flash gas may have substantially the same composition. The spent hot HP flash gas 507 can contain the water desorbed from the second adsorber vessel 520b in a heating step. The spent hot HP flash gas 507 can recycle the water back to the reforme r / reformi ng section 510 as process steam.In the embodiments described above in relation to Figures 9 and 10, heat from the hydrogen manufacturing unit can be continuously utilized, regardless of whether an adsorber vessel is in a heating phase or a cooling phase. This can provide effective integration of the dryer operation with the hydrogen manufacturing process, and can remove the need for a discontinuously operated heater (i.e. a heater which needs to be turned on for a heating phase and turned off for a cooling phase).Additional Options for Increased CO2 Capture Rate and Full Integration

[0100] In some embodiments, at least a portion of the warm HP Flash gas 56 is sent to a CO2 recovery unit 48 that can recover substantially all of the CO2 in the warm HP Flash gas to produce a stream 51 enriched in recovered CO2. In some embodiments, the stream enriched in recovered CO2 can be recycled back to the cryogenic section, upstream or downstream of the feed inlet compressor, depending on its pressure. In some embodiments, the remaining light gas components from the warm HP flash stream can be recovered in a separate residual gas stream 54 that can be used as fuel in thehydrogen manufacturing unit. In some embodiments, the CO2 recovery unit can be a solvent wash system that is selective for CO2 (e.g., amine or chilled methanol-based), an adsorption-based system that is selective for CO2 (pressure, temperature or electro swing adsorption, or a combination thereof), a membrane unit selective for the permeation of CO2, or any combination thereof. Increasing the CO2 capture rate of the hydrogen manufacturing unit can reduce the carbon intensity of the generated hydrogen product.

[0101] In other embodiments, the residual stream 54 from the CO2 recovery unit containing the remaining light gas components can be fed to a low-carbon fuel recovery unit. The low-carbon fuel recovery unit can recover the low-carbon molecules as a carbon-depleted stream that can be used as make-up fuel in the hydrogen manufacturing unit, while rejecting the carbon containing molecules to produce a carbon-enriched stream that can be recycled as a feed to the reforming section in the hydrogen manufacturing unit. In some embodiments, the low-carbon fuel recovery unit can be a PSA unit selective for the adsorption of carbon species, a membrane unit selective for the permeation of hydrogen, or a combination thereof. Reducing the carbon content of the make-up fuel to the hydrogen manufacturing unit fired heater can reduce the carbon emissions from the hydrogen manufacturing unit and lower the carbon intensity of the generated hydrogen product.

[0102] In still other embodiments, the residual stream 54 from the CO2 recovery unit containing the remaining light gas components can be fed to an inert gas rejection unit (IGRII). The inert gas rejection unit can reject the inert gases nitrogen, helium and argon from the residual stream, optionally together with a large fraction of the hydrogen, to produce an inert-gases enriched stream that can be used as make-up fuel in the hydrogen manufacturing unit, while recovering the carbon-containing molecules CO and CH4 as a carbon-enriched, inert-gases depleted stream that can be recycled as feed to the reforming section in the hydrogen manufacturing unit. The inert gases rejection unit can be a PSA unit selective for the rejection of inert gases and hydrogen, a membrane unit selective for the permeation of hydrogen and inert gases, or combinations thereof. Rejection of inert gases from the recycle loop of hydrocarbons back to the reforming section can eliminate the accumulation of these inert gases in the hydrogen manufacturing unit and reduce the power consumption of the recycle compressors.

[0103] Some embodiments involve generating a make-up fuel stream for the hydrogen manufacturing unit. This make-up fuel stream may, in some embodiments, be used for the regeneration of the TSA dryer vessel as an alternative to the warm HP Flash Gas, for example. For example, utilizing this fuel gas stream as the coolant medium for the TSA Dryer vessel in its cooling step could recover the heat towards a fuel stream. Pre-heating a fuel stream can reduce the required duty to be delivered by the furnace and the fuel demand, which can be beneficial to the energy efficiency of the hydrogen manufacturing unit.

[0104] The foregoing description of certain examples including the illustrated examples and process simulations above, has been presented only for the purpose of illustration and description and is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Numerous modifications, adaptations, and uses thereof will be apparent to those skilled in the art without departing from the scope of the disclosure. For instance, any examples described herein can be combined with any other examples to yield further examples. Any elements (e.g. streams and equipment) shown in any of the figures are not intended to be limiting (e.g., elements shown in some figures and not others) and are only exemplary embodiments. In addition, any reference in the claims to previously-mentioned specific equipment or processes, for example by number, is an example only and for clarity and should not limit the claims to that specific equipment or process.

[0105] Some further examples of the disclosure are set out below. As used below, any reference to a series of examples is to be understood as a reference to each of those examples disjunctively (e.g., "Example Nos. 1-4" or “Example No. 1 to Example No. 4” is to be understood as "Examples 1, 2, 3, or 4").

[0106] Example No. 1 is a method for processing a stream comprising residual CO2 and at least one of H2, Helium, CO, CH4, N2, Argon, or any combinations thereof, comprising: (a) dividing said stream into at least a first part and a second part, (b) using the first part as a regeneration gas for an adsorption process to regenerate an adsorber vessel loaded with adsorbed water by desorbing the adsorbed water into a spent regeneration gas stream, (c) recovering the spent regeneration gas stream as a feed to a plant applying a reforming reaction that converts CH4 with CO2 and / or H2O into H2 andCO, or a water gas shift section that converts CO and H2O into H2 and CO2, or any combination thereof, (d) heating the regeneration gas or the spent regeneration gas stream, or any combination thereof with residual heat from the plant using said reforming and / or water gas shift reactions, and (e) recovering said second part of the stream.

[0107] Example No. 2 is Example No. 1, wherein the adsorption process is a Temperature Swing Adsorption [TSA] process.

[0108] Example No. 3 is Example No. 1 or Example No. 2, wherein the adsorption process contains at least two adsorber vessels, of which at least one (optionally only one) adsorber vessel is in regeneration, and comprises: (a) routing the first part of the stream comprising residual CO2 as regeneration gas to bypass the adsorber vessel in regeneration (when the adsorber vessel in regeneration is to be heated), heating the regeneration gas with residual heat from the plant, and feeding the hot regeneration gas to the adsorber vessel in regeneration (when the adsorber vessel in regeneration is to be heated), collecting the spent regeneration gas and routing the spent regeneration gas to the reforming or water gas shift sections or combinations thereof via dedicated passageways; (b) routing the first part of the stream comprising residual CO2 as regeneration gas to enter the adsorber vessel in regeneration (when the adsorber vessel in regeneration is to be cooled), collecting the spent regeneration gas, and routing the heated spent regeneration gas to the reforming or water gas shift sections or combinations thereof via dedicated passageways after heating the spent regeneration gas with residual heat from the plant; (c) optionally completely bypassing the adsorber vessel in regeneration, routing the first part of the stream comprising residual CO2 directly to be heated, and then routing the heated first part of the steam comprising residual CO2 to the reforming or water gas shift sections or combinations thereof, via dedicated passageways (when the adsorber vessel in regeneration is idle); (d) using the same dedicated passageways to the reforming or water gas shift sections or combinations thereof, independent of the operation of the adsorber vessel in regeneration (heating I cooling I idle), and (e) using sequencing valves at the inlet and outlet of the adsorber vessel in regeneration to direct of the first part of the stream comprising residual CO2 as needed.

[0109] Example No. 4 is Example No. 1 or Example No. 2, wherein the adsorption process contains at least three adsorber vessels, of which at least two (optionally only two) are in different stages of regeneration, and comprises: (a) routing at least a first portion of the first part of the stream comprising residual CO2 as regeneration gas to enter an adsorber vessel in regeneration to be cooled, collecting the spent regeneration gas, (b) heating the spent regeneration gas and the remaining portion of the first part of the stream comprising residual CO2 to produce a heated regeneration gas, (c) routing at least part of the heated regeneration gas to an adsorber vessel in regeneration to be heated and collecting the spent heated regeneration gas and routing it with the remainder of the heated regeneration gas to the reforming or water gas shift sections or combinations thereof via dedicated passageways; and (d) utilizing sequencing valves at the inlets and outlets of the adsorber vessels in regeneration to be heated and cooled to direct the streams as needed.

[0110] Example No. 5 is any one of Example No. 1 to Example No. 4, wherein the stream comprising residual CO2 is generated in a hydrogen manufacturing plant, wherein the hydrogen manufacturing plant comprises: (a) a syngas production unit, (b) a water gas shift unit, (c) a heat recovery section, (d) a H2 purification section, (e) a compressor, (f) a temperature swing adsorption [TSA] dryer, (g) a cold box (multi-stream heat exchanger) with a refrigeration system, wherein the refrigeration system comprises: (1) a mixed refrigerant working fluid, comprising at least two components, and (2) a refrigerant loop with at least two different pressure levels, (h) a first phase separator generating the stream comprising residual CO2 and a first condensate, (i) optionally an expansion valve configured to expand the first condensate from the first phase separator, and (j) at least one of a second phase separator, and a distillation column, and (k) a system to recover at least a portion of the stream comprising residual CO2 and use that portion of the stream to regenerate the temperature swing adsorption dryer.

[0111] Example No. 6 is any one of Example No. 1 to Example No. 5, wherein the stream comprising residual CO2 is generated in a hydrogen manufacturing plant, comprising: (a) a syngas production unit, (b) a water gas shift unit, (c) a heat recovery section, (d) a H2 purification section, (e) a compressor, (f) a temperature swing adsorption [TSA] dryer, (g) a cold box (multi-stream heat exchanger) with a refrigeration system,wherein the refrigeration system comprises: (1) a mixed refrigerant working fluid, comprising at least two components, and (2) a refrigerant loop with at least two different pressure levels, (h) a first phase separator generating a first vapor and a first condensate, (i) optionally an expansion valve configured to expand the first condensate from the first phase separator, (j) at least one of a second phase separator, and a distillation column, (k) a CO2 recovery system separating the first vapor into a stream enriched in at least one of H2, Helium, CO, CH4, N2, Argon and containing residual CO2, and a second stream depleted in at least one of H2, Helium, CO, CH4, N2, Argon, and (I) a system to recover at least a portion of the stream enriched in at least one of H2, Helium, CO, CH4, N2, Argon and containing residual CO2, and use it to regenerate the temperature swing adsorption dryer.

[0112] Example No. 7 is Example No. 6, wherein the CO2 recovery system is a pressure swing adsorption system.

[0113] Example No. 8 is any one of Example No. 5 to Example No. 7, wherein the distillation column is operated without an overhead condenser.

[0114] Example No. 9 is any one of Example No. 5 to Example No. 8, wherein the syngas production unit comprises a reformer.

[0115] Example No. 10 is Example No. 9, wherein the reformer comprises an SMR, an ATR, a POX, a heat-exchanger reformer installed in series, a heat-exchanger reformer installed in parallel, or any combination thereof.

[0116] Example No. 11 is any one of Example No. 5 to Example No. 10, further comprising a heat exchanger after the compressor configured to chill a compressed feed stream.

[0117] Example No. 12 is any one of Example No. 5 to Example No. 11, wherein the cold box is configured to cool a dried feed stream at least partially using an overhead vapor stream from the distillation column, the first phase separator, the second phase separator, or any combination of vapor streams thereof.

[0118] Example No. 13 is any one of Example No. 5 to Example No. 12, wherein the multi-stream heat exchanger is configured to use a condensate from the second phase separator or a bottoms stream from the distillation column to chill the compressed feed stream.

[0119] Example No. 14 is any one of Example No. 5 to Example No. 13, wherein the cold box and first phase separator are configured to at least partially condense CO2 in a single stage.

[0120] Example No. 15 is any one of Example No. 5 to Example No. 14, wherein the refrigeration system is configured to operate at three or more pressure levels.

[0121] Example No. 16 is any one of Example No. 5 to Example No. 15, wherein the refrigeration package comprises a mixed refrigerant working fluid comprising CO2.

Claims

Claims1. A method for processing a stream comprising residual CO2 and at least one of H2, helium, CO, CH4, N2, argon, or any combinations thereof, comprising:dividing said stream into at least a first stream and a second stream, wherein the first stream is a CO2-depleted stream and the second stream is a CO2-rich stream; routing at least a first portion of the first stream to a heater to produce a heated regeneration gas for an adsorption process, wherein the heater heats the first portion of the first stream with residual heat from a plant applying a reforming reaction that converts CH4 with CO2 and / or H2O into H2 and CO, or a water gas shift section that converts CO and H2O into H2 and CO2, or any combination thereof;routing at least a first portion of the heated regeneration gas to an adsorber vessel to regenerate the adsorber vessel; andrecovering a first spent regeneration gas stream from the adsorber vessel as a feed to said plant.

2. The method of claim 1 , further comprising:routing a second portion of the first stream to the adsorber vessel, bypassing the heater;routing a second spent regeneration gas stream from the adsorber vessel to the heater to produce a heated second spent generation gas stream; andrecovering the heated second spent generation gas stream as a feed to said plant.

3. The method of claim 2, wherein the first portion of the first stream and the second portion of the first stream have substantially the same composition and / or the same pressure.

4. A method for processing a stream comprising residual CO2 and at least one of H2, Helium, CO, CH4, N2, Argon, or any combinations thereof, comprising:dividing said stream into at least a first stream and a second stream, wherein the first stream is a CO2-depleted stream and the second stream is a CO2-rich stream; routing at least a portion of the first stream to a first adsorber vessel as regeneration gas;routing a first spent regeneration gas stream from the first adsorber vessel to a heater to produce a heated regeneration gas for an adsorption process, wherein the heater heats the first spent regeneration gas stream with residual heat from a plant applying a reforming reaction that converts CH4 with CO2 and / or H2O into H2 and CO, or a water gas shift section that converts CO and H2O into H2 and CO2, or any combination thereof;routing at least a first portion of the heated regeneration gas to a second adsorber vessel to regenerate the second adsorber vessel; andrecovering a second spent regeneration gas stream from the second adsorber vessel as a feed to said plant.

5. The method of claim 4, further comprising combining the second spent regeneration gas stream with a second portion of the heated regeneration gas to provide a combined stream as the feed to said plant.

6. The method of claim 5, wherein the first portion of the heated regeneration gas and the second portion of the heated regeneration gas have substantially the same composition.

7. The method of any one of the preceding claims, wherein said reforming reaction or water gas shift section produces H2 from the spent regeneration gas stream.

8. The method of any one of the preceding claims, further comprising recovering the second stream.

9. The method of any one of the preceding claims, wherein said adsorption process is a temperate swing adsorption, TSA, process.

10. The method of any one of the preceding claims, wherein said adsorption process uses an adsorbent configured to adsorb water but not CO2.

11. The method of any one of the preceding claims, wherein said stream comprising residual CO2 comprises from 5 mole% CO2 to 20 mole% CO2, 7 mole% CO2 to 20 mole% CO2, or 10 mole% CO2 to 20 mole% CO2.

12. The method of any one of the preceding claims, wherein said stream comprising residual CO2 comprises from 5 mole% H2 to 20 mole% H2, from 7 mole% H2 to 20 mole% H2, or from 10 mole% H2 to 20 mole% H2.

13. The method of any one of the preceding claims, wherein said stream comprising residual CO2 is generated in a hydrogen manufacturing plant.

14. The method of claim 13, wherein the hydrogen manufacturing plant comprises a dryer comprising:i. the adsorber vessel, orii. the first adsorber vessel and the second adsorber vessel,optionally wherein the dryer is a temperature swing adsorption, TSA, dryer.

15. The method of claim 14, wherein the dryer is upstream of a CO2 recovery system.

16. The method of any one of claims 13 to 15, wherein the hydrogen manufacturing plant comprises at least one of:a. a syngas production unit,b. a water gas shift unit,c. a heat recovery section,d. a H2 purification section,e. a compressor,f. a first phase separator generating a first condensate,g. a second phase separator, andh. a distillation column, andoptionally further comprises:i. an expansion valve configured to expand the first condensate from the first phase separator.

17. The method of claim 16, wherein the first phase separator generates the stream comprising residual CO2, optionally wherein the hydrogen manufacturing plant comprises a system to recover at least a portion of the stream comprising residual CO2 and use that portion of the stream to regenerate a dryer of the hydrogen manufacturing plant.

18. The method of claim 16 or 17, wherein the first phase separator generates a first vapor, optionally wherein the hydrogen manufacturing plant comprises:a. a CO2 recovery system separating the first vapor into a stream enriched in at least one of H2, helium, CO, CH4, N2, argon and containing residual CO2, and a second stream depleted in at least one of H2, helium, CO, CH4, N2, argon, optionally wherein the CO2 recovery system is a pressure swing adsorption system, andb. a system to recover at least a portion of the stream enriched in at least one of H2, helium, CO, CH4, N2, argon and containing residual CO2, and use it to regenerate a dryer of the hydrogen manufacturing plant.

19. The method of any one of claims 13 to 18, wherein the hydrogen manufacturing plant comprises a cold box with a refrigeration system.

20. The method of claim 19, wherein the refrigeration system comprises a mixed refrigerant working fluid comprising at least two components and / or CO2; and / or wherein the refrigeration system comprises a refrigerant loop with at least two different pressure levels, and / or wherein the refrigeration system is configured to operate at three or more pressure levels.

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