Separation method
By condensing and separating condensable components upstream and adjusting the feed gas temperature, the process addresses condensation risks and energy inefficiencies, enabling efficient carbon dioxide production with cost-effective materials.
Patent Information
- Application Number
- JP2025507321
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-09-12
- Filing Date
- 2023-09-04
- Publication Date
- 2025-08-28
AI Technical Summary
Existing carbon dioxide capture processes face challenges in managing condensation risks during the compression of residual gas, particularly in winter, leading to increased energy consumption and material corrosion, while existing solutions either incur high capital costs or higher energy expenses.
A process involving a desaturation step to condense and separate condensable components upstream of the PSA unit, followed by heat exchange to raise the temperature of the feed gas, and subsequent compression stages using carbon steel alloys, reduces condensation risks and energy consumption.
This approach minimizes condensation-related constraints, lowers power consumption, and reduces capital expenditures by allowing the use of less expensive materials, thus optimizing the production of carbon dioxide-rich gas.
Smart Images
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Abstract
Description
[Technical Field]
[0001] The present invention relates to a process for producing a carbon dioxide-rich gas from synthesis gas. The present invention also relates to an installation for implementing such a process. [Background technology]
[0002] Carbon dioxide capture processes are most often used in producing hydrogen from synthesis gas from steam methane reforming and / or partial methane oxidation reactions in combination with a shift reaction of carbon monoxide with steam. To separate and purify (and possibly recover) the carbon dioxide contained in the synthesis gas, e.g., at cryogenic temperatures, the feed gas of the separation and purification unit must be dried to remove condensable components (mainly water, but possibly also methanol or ammonia). The goal is to avoid the solidification of water into ice, for example, when the separation and purification unit is a cryogenic unit that purifies and separates carbon dioxide by partial condensation. One typically used drying unit is an adsorption drying unit, e.g., a temperature swing adsorption drying unit (also called a TSA unit).
[0003] Synthesis gas (or syngas) typically consists of hydrogen at a level of 75%. The remaining 25% is separated into carbon dioxide and condensable components including methane, nitrogen, residual carbon monoxide, and water, among others. The synthesis gas first passes through a pressure swing adsorption separation unit (also called a PSA unit) to separate first into hydrogen and second into a carbon dioxide-rich residue gas. The synthesis gas from the steam reforming reaction, partial methane oxidation reaction, and / or potentially the steam shift reaction is usually cooled to a temperature of approximately 30°C or 40°C before being sent to the PSA unit. The gas typically arrives saturated with water at a pressure of 20 to 60 bara.
[0004] The residue gas must be compressed and cooled to allow its drying and, finally, the separation and purification of the carbon dioxide in a separation and purification unit. Compression is typically performed at 50 bara. Other gases in the residue gas are burned, for example, in a furnace where a reforming reaction takes place.
[0005] Cooling the residual gas during compression reduces the energy consumption of the compression step. Therefore, to cool the compressed residual gas, compression and cooling devices are used, including one or more compression stages and a so-called intercooling heat exchanger located between two compression stages. Intercooling heat exchangers are also called intercoolers. Water is typically used as the cooling fluid in these cooling exchangers, and the water may be cooled in a cooling tower. When cooling and compressing the residual gas in such a cooling exchanger, the residual gas may reach its dew point, causing the problem of condensable components condensing. One or more condensates, primarily composed of water and dissolved carbon dioxide, are generated. They are quite acidic (pH about 3).
[0006] Various strategies have been implemented in the prior art to minimize the costs associated with compressing residue gas.
[0007] The use of corrosion-resistant materials such as stainless steel for the compression devices, especially the intermediate exchangers, allows the residue gas to be dried at high pressure levels without the risk of corrosion of the materials by condensable components. The relatively high pressure reduces drying costs and correspondingly operating costs. However, such materials result in increased capital expenditures.
[0008] Drying the residual gas upstream of compression allows for the use of less expensive materials, such as carbon steel, in the compression device because condensable components have been removed, but results in higher drying costs due to the large amount of condensable components removed, the high volumetric flow rates, and the low pressure adsorption isotherms.
[0009] Drying the residual gas in an intermediate compression stage is known as a compromise solution, allowing for the use of carbon steel in the compression stage downstream of the drying unit while reducing the cost of drying performed at higher pressures. Drying units (or dryers) are typically located at compression stages around 10 bara. It is also common practice to utilize devices upstream of the drying unit to condense condensable components through cooling to process the residual gas obtained from the PSA unit. Such devices, for example, use chilled water to maximize condensation upstream of the dryer. However, maintaining the residual gas at a temperature 7–10°C above the dew point temperature of the condensable components is necessary to maintain the carbon steel in the compression stage upstream of the drying unit. This provides a safety margin against potential temperature fluctuations that could result in the accidental condensation of condensable components. Maintaining the residual gas at such a higher temperature requires compression at a higher temperature, which consumes more energy. Summary of the Invention [Problem to be solved by the invention]
[0010] During this compression step, it is generally difficult to manage the risk of condensation upstream of the drying unit in a timely manner, especially in the upper compression stage. Furthermore, the risk of accidental condensation increases even more when temperatures drop in winter. Therefore, there is a need for a process that produces carbon dioxide-rich gas with fewer condensation-related constraints and lower power consumption. [Means for solving the problem]
[0011] The subject of the present invention is therefore a process for producing a carbon dioxide-rich gas from a feed syngas comprising at least one condensable component, in particular a feed syngas comprising hydrogen, comprising the steps of: a) introducing a desaturated synthesis gas obtained from a feed synthesis gas into a unit for separation by pressure swing adsorption (PSA unit), b) separating the desaturated synthesis gas into a first fraction and a carbon dioxide-enriched residue gas by a pressure swing adsorption separation unit; c) compressing the residual gas in at least two compression stages and cooling the compressed residual gas in at least one intermediate compression stage; In a process including a desaturation step in which at least a portion of at least one condensable component contained in the feed synthesis gas is condensed and separated upstream of the pressure swing adsorption separation unit by cooling to a temperature below 10°C, in particular below 5°C, to produce the desaturated synthesis gas and at least one condensate; - subjecting the feed syngas to heat exchange with the desaturated syngas to heat said desaturated syngas upstream of the pressure swing adsorption separation unit. The process further comprises:
[0012] Contrary to the prior art finding that the residual gas is treated in such a way as to maximize the condensation of condensable components upstream of the dryer by means of a device for condensing said components by cooling, the present invention proposes to treat the feed gas of a PSA unit, as it is known from the prior art that rigorous cooling of the feed gas of a PSA unit does not contribute anything from the standpoint of this unit or even causes impairment of its operation.
[0013] Removing at least a portion of the condensable components from the PSA unit feed gas reduces the risk of accidental condensation of said components in step c) after a certain compression stage. Heating the thoroughly cooled PSA unit feed gas in the desaturation step brings it back into a temperature range compatible with the proper operation of the PSA unit.
[0014] According to one implementation of the process, the feed syngas comprises 70% to 80% hydrogen and 20% to 30% other compounds, including carbon dioxide, at least one condensable component, optionally residual methane and residual carbon monoxide, and, for example, nitrogen. In particular, the first fraction is enriched in hydrogen.
[0015] According to one implementation of the process, the at least one condensable component is selected from water, ammonia, and / or methanol.
[0016] According to one implementation of the process, the desaturated synthesis gas contains 150-700 ppmv of condensable components, in particular 150-700 ppmv of water.
[0017] According to one implementation of the process, in the desaturation step, condensation of at least one condensable component is carried out by cooling the feed syngas using a refrigerant fluid, more particularly selected from cold water, cold air or a coolant fluid.
[0018] According to one implementation of the process, the feed syngas undergoes heat exchange with the desaturated syngas in an economizer exchanger, and the minimum temperature difference between the feed syngas and the desaturated syngas in the economizer exchanger is 2 to 10° C., particularly 5 to 10° C. The temperature of the desaturated syngas is particularly 20 to 40° C., particularly 30 to 40° C.
[0019] According to one implementation of the process, the first fraction is enriched in hydrogen.
[0020] According to one implementation, the process comprises a step d) in which the residual gas is dried by adsorption in order to separate residual condensable components from the residual gas.
[0021] According to one implementation of the process, the residual gas is dried during step d) downstream of compression step c). Alternatively, the residual gas is dried during step d) at an intermediate compression stage during step c).
[0022] According to one implementation of the process, in step d), the residual gas is dried by adsorption in a unit for drying residual gas by adsorption, the process comprising a regeneration step of said unit for drying residual gas by adsorption.
[0023] According to one implementation, the process comprises, downstream of step c) and optionally downstream of step d) (if such a step is present), a step e) in which carbon dioxide is separated from the residual gas so as to be recovered or sequestered. Carbon dioxide is separated, inter alia, during step e), by partial condensation, in which the carbon dioxide is at least partially condensed. Alternatively, carbon dioxide is separated from the residual gas using a membrane in a membrane unit. Alternatively, carbon dioxide is separated by a combination of partial condensation separation and membrane separation.
[0024] According to one implementation, the process comprises a step of cooling the feed syngas upstream of the desaturation step, inter alia using a cooling fluid, such as cooling water or air, which is carried out in at least one heat exchanger, known as a feed heat exchanger, located inter alia upstream of the desaturation step.
[0025] According to one implementation, the process includes: - measuring the temperature of the desaturated synthesis gas; - comparing the measured temperature of the desaturated syngas to a minimum setpoint temperature of the desaturated syngas introduced into the pressure swing adsorption separation unit; - adjusting the temperature of the desaturated syngas by reducing cooling of the feed syngas in the feed heat exchanger if the measured temperature of the desaturated syngas is less than the minimum setpoint temperature; Includes.
[0026] A further subject of the present invention is an installation for producing a carbon dioxide-enriched gas from a feed syngas comprising at least one condensable component, in particular a feed syngas comprising hydrogen, comprising: - a pressure swing adsorption separation unit (PSA unit) configured to separate a desaturated synthesis gas obtained from the feed synthesis gas into a first fraction and a carbon dioxide-enriched residue gas; a compression device arranged downstream of the pressure swing adsorption separation unit, the compression device including at least two stages for compressing the residue gas and an intermediate exchanger for cooling at least one compressed residue gas in the intermediate compression stages; In facilities including - a condensation and separation device with refrigeration upstream of the pressure swing adsorption separation unit, configured to condense and separate at least a portion of the condensable components contained in the feed syngas and produce a desaturated syngas and at least one condensate; an economizer exchanger arranged to provide heat exchange between the feed syngas and the desaturated syngas; The equipment is characterized by comprising:
[0027] According to one embodiment, the pressure swing adsorption separation unit is configured to separate the desaturated synthesis gas into a first hydrogen-rich fraction and a carbon dioxide-rich residue gas.
[0028] According to one embodiment, the facility comprises a residual gas adsorptive drying unit configured to separate residual condensable components from the residual gas.
[0029] According to one embodiment, the installation comprises a separation and purification unit downstream of the compression device, in particular optionally downstream of the residue gas drying unit, configured to separate carbon dioxide from the compressed and optionally dried residue gas for recovery or sequestration of said carbon dioxide. The separation and purification unit comprises, inter alia, a unit configured to separate carbon dioxide from the residue gas by partial condensation. Alternatively, the separation and purification unit comprises a membrane unit configured to separate carbon dioxide from the residue gas using a membrane. Alternatively, the separation and purification unit comprises a combination of a unit configured to separate carbon dioxide by partial condensation and a membrane unit for separation of carbon dioxide from the residue gas.
[0030] According to one embodiment, the condensation and separation device by cooling comprises: - a two-fluid exchanger including a section for circulating a feed syngas for cooling the feed syngas, condensing condensable compounds, and producing a desaturated syngas and at least one condensate, and a section for circulating a refrigerant fluid, the section being arranged to exchange heat with the section for circulating the feed syngas; - a condensate separation device configured to separate at least one condensate from the desaturated synthesis gas; The two-fluid exchanger is in particular a shell-and-tube exchanger, in which the section for circulating the refrigerant fluid is defined by the interior space of at least one tube housed in the shell, and the section for circulating the feed syngas is defined by the space between the shell and the at least one tube. The device for separating the at least one condensate is, for example, a phase separator can. The condensation and separation device by cooling includes, in particular, a refrigeration assembly for cooling the refrigerant fluid.
[0031] According to one embodiment, the economizer exchanger comprises: - a first section for circulating the feed syngas, a second section for circulating desaturated synthesis gas, the second section being arranged to exchange heat with the first section; The economizer exchanger is in particular a shell-and-tube exchanger, in which the section for circulating the desaturated synthesis gas is defined by the internal space of at least one tube housed in the shell, and the section for circulating the feed synthesis gas is defined by the space between the shell and the at least one tube.
[0032] According to one embodiment, the installation comprises at least one feed heat exchanger upstream of the first section of the economizer exchanger, arranged to regulate the temperature of the feed syngas, the feed heat exchanger comprising in particular a feed syngas circulation channel and a channel for circulating a cooling fluid, e.g., cooling water or air, the cooling fluid circulation channel being arranged to exchange heat with the feed syngas circulation channel.
[0033] According to one embodiment, the compression device, and in particular at least one intermediate exchanger of said compression device, is at least partly made of a carbon steel alloy.
[0034] According to one embodiment, the adsorption drying unit is located downstream of the compression device. Alternatively, the adsorption drying unit is located at an intermediate compression stage of the compression device. The adsorption drying unit is a regenerable unit, such as a temperature swing adsorption drying unit (TSA unit), among others.
[0035] Any facility for producing carbon dioxide enriched gas can be used to implement the process described above.
[0036] The present invention also relates to a process for retrofitting a facility for producing a carbon dioxide-rich gas from a feed syngas comprising at least one condensable component, in particular a feed syngas comprising hydrogen, the facility comprising: - a pressure swing adsorption separation unit configured to separate a desaturated synthesis gas obtained from the feed synthesis gas into a first fraction and a carbon dioxide-enriched residue gas; a compression device arranged downstream of the pressure swing adsorption separation unit, the compression device including at least two stages for compressing the residue gas and an intermediate exchanger for cooling at least one compressed residue gas in the intermediate compression stages; The process comprises: - disposing a refrigeration condensation and separation device upstream of the pressure swing adsorption separation unit, the condensation and separation device configured to condense and separate at least a portion of at least one condensable component contained in the feed syngas to produce a desaturated syngas and at least one condensate; - disposing a first circulation section of the economizer exchanger upstream of the cooling condensation and separation device for circulating the feed synthesis gas, and disposing a second circulation section of the economizer exchanger downstream of the cooling condensation and separation device and upstream of the pressure swing adsorption separation unit for circulating the desaturated synthesis gas. Includes. [Brief explanation of the drawings]
[0037] [Figure 1] FIG. 1 depicts a facility for producing carbon dioxide-rich gas from feed synthesis gas 16 (or syngas). DETAILED DESCRIPTION OF THE INVENTION
[0038] In the illustrated embodiment, feed syngas 16 is produced in a unit for hydrogen production and contains hydrogen. It is a synthesis gas that typically contains 70% to 80% hydrogen and 20% to 30% other compounds, including carbon dioxide, at least one condensable component (plurality of "condensable components" in this embodiment), unconverted methane, unconverted carbon monoxide, and nitrogen. The feed syngas may or may not be saturated with condensable components, for example.
[0039] The synthesis gas is processed in a pressure swing adsorption separation unit 1 (also called a PSA unit) to separate the synthesis gas into a hydrogen-enriched first fraction and a carbon dioxide-enriched residue gas 2. PSA unit 1 includes a first outlet for the first hydrogen-enriched fraction (hydrogen PSA) and a second outlet for the produced residue gas 2. A line feeds the synthesis gas to PSA unit 1. Pressure swing adsorption separation unit 1 can recover up to 90% of the hydrogen initially contained in the synthesis gas.
[0040] Upstream of the pressure swing adsorption separation unit 1, the feed syngas 16 is separated from at least some of its condensable components (here, mainly water) in a cooling condensation and separation device, which produces a desaturated syngas 17 and a condensate 6. The desaturated syngas 17 contains, among other things, 150 to 700 ppmv of water. This device includes a two-fluid exchanger 3, which itself includes a circulation section 4 for the feed syngas 16 and a circulation section 5 for a refrigerant fluid, both of which are arranged on a line 16 for supplying syngas to the PSA unit 1. These two sections are arranged in the two-fluid exchanger 3 so as to exchange heat with each other. The two-fluid exchanger 3 thus enables heat exchange between the refrigerant fluid and the feed syngas 16, which cools the feed syngas 16 to a temperature below 10°C, preferably below 5°C. This cooling therefore causes condensation of some of the condensable components contained in the feed syngas 16 to give the condensate 6. The PSA unit 1 then processes the gas from which some of its condensable components have been removed, simplifying its regeneration. This reduces the risk of accidental condensation during the compression step of the residue gas 2 produced by the PSA unit 1. The refrigerant fluid is, for example, chilled water, chilled air or a coolant fluid. After being cooled by a refrigeration assembly (not shown), the refrigerant fluid is supplied to the binary fluid exchanger 3. The binary fluid exchanger 3 is typically a shell-and-tube exchanger, in which the section for circulating the refrigerant fluid is defined by the interior space of at least one tube housed in a shell, and the section for circulating the synthesis gas is defined by the space between the shell and the at least one tube.
[0041] The condensate 6 is then separated in a condensate separation device 6. The condensate separation device 6 and the two-fluid exchanger 3 may be integrated, in which case the condensate separation 6 takes place in the body of the exchanger itself, or the heat exchange takes place in the condensate separation device 6. Alternatively, the condensate separation device 6 may constitute a separate unit from the two-fluid exchanger 3 in the condensation and separation device by cooling. The condensate separation device 6 is, for example, a phase separator can.
[0042] The system includes an economizer exchanger 7 arranged to exchange heat between the feed syngas 16 and the desaturated syngas 17. To this end, the economizer exchanger 7 includes a first circulation section 8 for the feed syngas 16, which is arranged in an upstream portion of the feed line of the PSA unit 1 (relative to the cooling condensation and separation device). The economizer exchanger 7 further includes a second circulation section 9 for the desaturated syngas 17, which is arranged in a portion of the feed line of the PSA unit 1 downstream of the cooling condensation and separation device. These two sections are arranged in the economizer exchanger 7 to exchange heat with each other. Thus, the economizer exchanger 7 allows heat exchange between the feed syngas 16 (not desaturated) and the desaturated syngas 17. The minimum temperature difference (minimum temperature approach) between the two circulation sections of the economizer exchanger 7 is 2 to 10°C, preferably 5 to 10°C. Thus, the feed syngas 16 heats the desaturated syngas 17 before it is sent to the PSA unit 1. The economizer exchanger 7 is typically a shell-and-tube exchanger, where the section for circulating the desaturated syngas 17 is defined by the interior space of at least one tube housed in a shell, and the section for circulating the feed syngas 16 is defined by the shell and the space between the at least one tube, thereby avoiding the adverse effects of thorough cooling caused by cooling condensation and separation devices upstream of the unit.
[0043] From the viewpoint of the present process, if the economizer exchanger 7 is not sufficient to compensate for the cooling effect on the PSA unit 1, it is proposed to adjust the temperature of the feed syngas 16 obtained from the reforming unit and / or from the partial oxidation unit by utilizing a heat exchanger 15 arranged upstream of the economizer exchanger 7 and the cooling condensation and separation device (feed exchanger 15). A typical adjustment involves measuring the temperature of the desaturated syngas 17 and comparing it with the minimum setpoint temperature of the desaturated syngas 17 entering the pressure swing adsorption separation unit. If the temperature of the feed syngas 16 is too low, i.e., below the minimum setpoint temperature, it is possible to limit the cooling of the feed syngas 16 by reducing the flow rate of the cooling fluid (selected from cooling water or air) circulating in the feed exchanger 15 and / or by bypassing said feed exchanger 15 for part of the syngas (wherein this part of the feed syngas 16 is no longer cooled and is mixed with the part cooled in the heat exchanger 15). This operation is carried out until the measured temperature of the desaturated synthesis gas 17 is equal to or greater than the minimum set point temperature. A calculation and control unit (not shown) makes it possible to make the measurements and calculations necessary for such adjustments.
[0044] Since the economizer exchanger 7 provides most of the cooling, the cooling condensation and separation device only serves to adjust the cooling temperature, and its size and energy consumption can be reduced. Then, the binary fluid exchanger 3 only needs to provide condensation energy for the condensable components, and does not need to provide cooling energy for other compounds in the synthesis gas, such as hydrogen.
[0045] Thus, the desaturated synthesis gas 17 is typically fed to the PSA unit 1 at a temperature of 30-40°C and a pressure of 20-60 bara (bar absolute). The PSA unit 1 then produces a residue gas 2, which is then compressed in a compression device 10. The compression device 10 comprises two compression stages 11a, 11b, or compression levels of the residue gas 2. However, in other embodiments, the compression device 10 may comprise three or more compression stages. After compression to the first compression level, the residue gas 2 is cooled in an intermediate exchanger 12 (intercooler) to cool the compressed residue gas of the intermediate compression stage 11a. Due to the fact that at least a portion of the condensate is removed downstream of the PSA unit, the residue gas 2 can be further cooled without the risk of condensation in the intermediate exchanger 12. The compression device 10 then compresses the residue gas 2 with less energy consumption. In the intermediate exchanger 12, water cooled in a cooling tower (not shown) typically serves as the cooling fluid. The intermediate exchanger 12 is at least partially made of a carbon steel alloy, which is possible due to the reduced risk of condensation. Such materials are less expensive than stainless steel. In particular, such alloys are not designed to withstand compounds with a pH below 4. The compression stages correspond to the compression levels reached at the outlet of the compression elements, such as compression wheels, in the compression device 10. The intermediate compression stages are then located between two compression elements of the compression device 10.
[0046] In one embodiment, not shown, the compressed residue gas obtained from compression device 10 is cooled in a final cooling exchanger. The compressed residue gas obtained from compression device 10 is sent to a temperature swing adsorption drying unit 13 (TSA unit), where the residue gas is stripped of any remaining condensable components by adsorption. TSA unit 13 cycles between a production step, in which the residue gas is dried, and a regeneration step, in which the adsorbent is regenerated. In the embodiment of FIG. 1 , drying by TSA unit 13 is performed downstream of compression device 10 after the compression step, at a pressure of about 50 bara. In another embodiment, drying by TSA unit 13 can also be performed at a pressure of about 10 bara in an intermediate compression stage 11a of compression device 12.
[0047] After drying, the carbon dioxide-enriched residual gas is sent to a separation and purification unit 14, where upon partial condensation, the carbon dioxide is separated from other components of the residual gas to produce a liquid phase and a gas phase, and the carbon dioxide is at least partially condensed into the liquid phase. The separation and purification unit 14 includes, among other things, a membrane unit (not shown) configured to separate the residual gaseous carbon dioxide in the gas phase from other gaseous components in the gas phase. Alternatively, the separation and purification unit includes a membrane unit that separates carbon dioxide solely from other components of the residual gas. The separation and purification unit allows carbon dioxide to be captured without being released to the atmosphere, thereby improving the carbon balance of the hydrogen production.
[0048] A standard carbon dioxide-rich gas production facility can be adapted to integrate the cooling condensation and separation device described above with the economizer exchanger 7 and implement a process that is less restrictive from a condensation point of view.
[0049] In addition to steam reforming processes, the process of the present invention is also applicable to autothermal reforming and partial oxidation processes.
[0050] The present invention allows for the use of compression and cooling devices made partially of carbon steel. This reduces capital expenditures on compression devices. Additionally, reducing the content of condensable components in the synthesis gas, and thus the residual gas, allows for further cooling of the latter gas during the compression step, thereby saving more energy. Furthermore, if it is necessary to separate the residual condensable components from the residual gas, the drying unit 13 can perform drying by adsorption at pressures higher than the approximately 10 bara typically used in the prior art, without requiring stainless steel compression and cooling devices. This reduces drying costs and allows for the use of smaller drying units. The start-up phase of the process is less restrictive in terms of preheating the system, since the risk of condensation due to excessively cold temperatures is reduced. By condensing a portion of the condensable components contained in the synthesis gas upstream of the PSA unit 1, certain impurities are removed via the condensate, thereby limiting their amount in the residual gas. Condensates other than water that may be present in the synthesis gas, such as methanol or ammonia, can be removed. These impurities or condensates would otherwise have to be treated by catalytic units or oversized adsorption drying units designed for this purpose.
Claims
1. 1. A process for producing a carbon dioxide-rich gas from a feed synthesis gas (16) comprising at least one condensable component and, inter alia, hydrogen, comprising: a) introducing desaturated synthesis gas (17) obtained from said feed synthesis gas (16) into a unit (1) for separation by pressure swing adsorption; b) separating the desaturated synthesis gas (17) into a first fraction and a carbon dioxide-enriched residue gas (2) by means of the pressure swing adsorption separation unit (1); c) compressing said residue gas (2) in at least two compression stages (11a, 11b) and cooling said compressed residue gas in at least one intermediate compression stage; In a process including a desaturation step in which at least a portion of the condensable components contained in the feed synthesis gas (16) are condensed and separated upstream of the pressure swing adsorption separation unit (1) by cooling to a temperature below 10°C, in particular below 5°C, to produce the desaturated synthesis gas (17) and at least one condensate (6); - the feed synthesis gas (16) is subjected to heat exchange with the desaturated synthesis gas (17) in order to heat the desaturated synthesis gas (17) upstream of the pressure swing adsorption separation unit (1); The process further comprising:
2. 10. The process of claim 1, wherein the feed syngas (16) comprises 70% to 80% hydrogen and 20% to 30% other compounds, including carbon dioxide and the condensable components.
3. 3. The process of claim 1 or 2, wherein the condensable components are selected from water, ammonia and / or methanol.
4. The process of any one of claims 1 to 3, wherein in the desaturation step, the condensation of the condensable components is carried out by cooling the feed syngas (16) using a refrigerant fluid.
5. 5. The process according to any one of claims 1 to 4, wherein the feed syngas (16) undergoes heat exchange with the desaturated syngas (17) in an economizer exchanger (7), and the minimum temperature difference between the feed syngas (16) and the desaturated syngas (17) in the economizer exchanger (7) is 2 to 10°C, in particular 5 to 10°C.
6. 6. The process according to any one of claims 1 to 5, comprising a step d) in which the residual gas is dried by adsorption in order to separate residual condensable components from the residual gas.
7. 7. The process of claim 6, wherein the residue gas is dried during step d) downstream of the compression step c).
8. 7. The process according to claim 6, wherein the residue gas is dried during step d) in an intermediate compression stage (11a).
9. 9. The process of any one of claims 1 to 8, comprising a step e) downstream of step c), in which the carbon dioxide is separated from the residual gas so as to be captured or sequestered.
10. 10. The process of claim 9, wherein the carbon dioxide is separated in step e) by partial condensation, wherein the carbon dioxide is at least partially condensed, and / or the carbon dioxide is separated using a membrane in a membrane unit.
11. - measuring the temperature of the desaturated synthesis gas (17), - comparing the measured temperature of the desaturated synthesis gas (17) with a minimum set point temperature of the desaturated synthesis gas (17) introduced into the pressure swing adsorption separation unit; - adjusting the temperature of the desaturated synthesis gas (17) by reducing the cooling of the feed synthesis gas (16) in at least one feed heat exchanger (15) arranged upstream of the desaturation step if the measured temperature of the desaturated synthesis gas (17) is lower than the minimum set point temperature. The process according to any one of claims 1 to 10, comprising:
12. 1. An installation for producing a carbon dioxide-rich gas from a feed synthesis gas (16) comprising at least one condensable component and, inter alia, hydrogen, comprising: a pressure swing adsorption separation unit (1) configured to separate a desaturated synthesis gas (17) obtained from said feed synthesis gas (16) into a first fraction and a carbon dioxide-enriched residue gas (2); a compression device (10) arranged downstream of said pressure swing adsorption separation unit (1), said compression device (10) comprising at least two stages (11a, 11b) for compressing said residue gas (2) and at least one intermediate exchanger (12) for cooling said compressed residue gas in the intermediate compression stages; In facilities including a condensation and separation device with cooling upstream of the pressure swing adsorption separation unit (1), configured to condense and separate at least a portion of the condensable components contained in the feed synthesis gas (16) and to produce the desaturated synthesis gas (17) and at least one condensate (6); an economizer exchanger (7) arranged to provide a heat exchange between said feed synthesis gas (16) and said desaturated synthesis gas (17); An equipment comprising:
13. 13. The installation according to claim 12, comprising a residual gas adsorption drying unit (13) configured to separate residual condensable components from the residual gas (2).
14. The cooling condensation and separation device comprises: a two-fluid exchanger (3) comprising a section (4) for circulating the feed synthesis gas (16) to cool the feed synthesis gas (16), condense the condensable compounds and produce the desaturated synthesis gas (17) and the condensate (6), and a section (5) for circulating a refrigerant fluid arranged to exchange heat with the section (4) for circulating the feed synthesis gas (16); a condensate separation device configured to separate said condensate (6) from said desaturated synthesis gas (17); 14. The installation according to claim 12 or 13, comprising:
15. The economizer exchanger (7) a first section (8) for circulating said feed synthesis gas (16), a second section (9) for circulating said desaturated synthesis gas (17), arranged in heat exchange with said first section (8); The facility according to any one of claims 12 to 14, comprising: