Process and equipment for separating a feed flow containing hydrogen, carbon dioxide, and at least one component selected from the list of carbon monoxide, methane, or nitrogen
The integration of a turbine and booster system optimizes the separation of hydrogen, carbon dioxide, and other gases by utilizing expansion energy, enhancing separation efficiency and reducing energy costs.
Patent Information
- Application Number
- JP2025512852
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-09-08
- Filing Date
- 2023-08-29
- Publication Date
- 2025-09-09
AI Technical Summary
Existing methods for separating hydrogen, carbon dioxide, and other components like carbon monoxide, methane, or nitrogen are inefficient in utilizing expansion energy from membrane residue, leading to suboptimal energy recovery and separation efficiency.
Integrating a turbine coupled with a booster to utilize the expansion energy of the membrane residue, enhancing the separation process through multiple stages of membrane separation and optional heating/cooling steps to optimize permeate and retentate composition.
Improves the separation efficiency of hydrogen and carbon dioxide by 14-20% while reducing energy costs, allowing for better yield and energy recovery.
Smart Images
Figure 2025529958000001_ABST
Abstract
Description
[Technical Field]
[0001] The present invention relates to a process and apparatus for separating a feed flow containing hydrogen, carbon dioxide, and at least one component selected from the list of carbon monoxide, methane, or nitrogen. The process comprises a membrane separation step of a mixture containing primarily hydrogen, carbon dioxide, and at least one other component selected from the list of carbon monoxide, methane, and nitrogen. [Background technology]
[0002] The mixture containing primarily hydrogen and carbon dioxide has a composition such that at least 50 mol % of the mixture is made up of hydrogen and carbon dioxide.
[0003] The capture of carbon dioxide (CO2) by a distillation and / or partial condensation process is known, which is provided by the residue gas from a hydrogen (H2) production unit containing a pressure swing adsorption (PSA) hydrogen separation unit. The residue gas is depleted in hydrogen compared to the gas supplied to this separation unit. The separation unit can be combined with a membrane separation of the carbon dioxide-depleted gas produced by the distillation and / or partial condensation process. The goal of such a membrane is to separate CO2 and H2 from the remainder of the gas in two steps. The permeate of the first membrane is recycled to the PSA, while the permeate of the second membrane is returned to the compressor upstream of the distillation and / or partial condensation separation to be compressed itself. The membrane residue, still under pressure, is expanded by a valve before regeneration of the dryer. This energy can be recovered to improve the efficiency of the CO2 capture process.
[0004] US Patent No. 4,639,257 describes passing the residual gas from the cryogenic separation through an economizer before passing it to a first membrane, the permeate of which is recycled upstream of the compressor for the gas fed to the cryogenic separation. Summary of the Invention [Means for solving the problem]
[0005] The present invention proposes an improved process using an integration scheme of at least one turbine coupled to at least one booster so as to better utilize the expansion energy of the second residue of the membrane.
[0006] According to one aspect of the present invention, a method for producing ... semiconductor device is provided, comprising the steps of: a) compressing the feed flow in a compressor, dehydrating the feed flow in an adsorption purification unit and / or cooling the dehydration purified flow in an exchange line, separating the purified and / or cooled feed flow by partial condensation and / or distillation to form a carbon dioxide-rich flow and a mixture containing primarily hydrogen, carbon dioxide, and at least one component selected from the list of carbon monoxide, methane, or nitrogen; and b) Follow the steps below: i. optionally, heating the mixture in a heat exchanger to a temperature of 60-100°C; ii. permeation of the optionally heated mixture through a first membrane making it possible to obtain a first permeate enriched in hydrogen and carbon dioxide compared to the mixture and a first retentate depleted in hydrogen and carbon dioxide compared to the mixture; iii. optionally, cooling at least a portion of the first permeate in a heat exchanger; iv. Compression of the optionally cooled first permeate in a first booster; v. optionally, cooling at least a portion of the first booster compressed first permeate in a heat exchanger; vi. permeation of the first retentate, preferably uncooled, through a second membrane, making it possible to obtain a second permeate enriched in hydrogen and carbon dioxide compared to the first retentate, and a second retentate depleted in hydrogen and carbon dioxide compared to the first retentate; vii. optionally, cooling at least a portion of the second permeate in a heat exchanger; viii. Compression of the optionally cooled second permeate in a second booster; ix. optionally, cooling at least a portion of the compressed second permeate in a heat exchanger; and x. Expansion of the second residue in at least one turbine driving the first and / or second booster; Separation of mixtures by membrane separation processes including The present invention provides a process for separating a feed flow containing hydrogen, carbon dioxide, at least one component selected from the list of carbon monoxide, methane, or nitrogen, and optionally water, comprising:
[0007] Other optional aspects are as follows: At least a portion of the expanded second residue is sent to the purification unit as regeneration gas. At least a portion of the expanded second residue is sent to an exchange line to contribute cold. At least a portion of the expanded second residue is sent to a burner of a reformer. The mixture is optionally heated in a heat exchanger to a temperature of 60-100°C. The mixture is heated by indirect heat exchange in a heat exchanger with at least a portion of at least one of the following flows: the first permeate, the first retentate, the second permeate, the second retentate. The second residue is expanded in two turbines in turn, each of which drives one of the first and second boosters. The second residue, expanded in two turbines, is at a pressure of 3-5 bara and / or a temperature of -30 to -55°C after expansion. The feed flow is compressed in a compressor upstream of the partial condensation and / or distillation, and the second permeate compressed by the second booster is sent to the compressor to be compressed. The second residue is enriched in carbon monoxide and / or methane and / or nitrogen compared to the first residue.
[0008] According to another subject of the invention, there is provided a compressor, a purification unit and / or an exchange line, means for sending the feed flow compressed by the compressor to the purification unit and / or to the exchange line, a separation unit for the purified and / or cooled feed flow by partial condensation and / or distillation to form a carbon dioxide-rich flow and a mixture containing mainly hydrogen, carbon dioxide and at least one component selected from the list of carbon monoxide, methane or nitrogen, means for sending the feed flow from the purification unit and / or the exchange line to the separation unit, a first membrane and a duct for sending the mixture to be separated to the first membrane, which makes it possible to obtain a first permeate enriched in hydrogen and carbon dioxide compared to the mixture and a first retentate depleted in hydrogen and carbon dioxide compared to the mixture. and at least one expansion turbine connected to expand the second retentate to drive the first and / or second booster.
[0009] According to another optional feature, the device comprises: means for sending the second residue as regeneration gas from the at least one expansion turbine to the purification unit; means for sending the second residue from the at least one expansion turbine to an exchange line so as to contribute cold; means for delivering the second residue from the at least one expansion turbine to a burner of the reformer; The feed flow is the residue gas from the pressure swing adsorption unit. a purification unit and means for delivering the compressor-compressed feed flow to the purification unit; an exchange line and means for directing the compressor-compressed feed flow to the exchange line; Includes.
[0010] Preferably, the apparatus includes two expansion turbines in series, each connected to drive one of the first and second boosters.
[0011] The invention will now be described in more detail with reference to the figures. [Brief explanation of the drawings]
[0012] [Figure 1] FIG. 1 depicts a separation process according to the present invention. DETAILED DESCRIPTION OF THE INVENTION
[0013] A hydrogen (H2) production unit that includes a pressure swing adsorption (PSA) hydrogen separation unit produces a hydrogen-rich gas and a residue gas that is hydrogen-depleted compared to the feed gas but also contains carbon dioxide and nitrogen and / or methane and / or carbon monoxide.
[0014] The residue gas is compressed by a compressor C, dried by a drier in the adsorption purification unit, cooled in a heat exchanger called an exchange line, and then separated by partial condensation and / or distillation to produce a carbon dioxide-rich fluid and a carbon dioxide-depleted gas 1. The fluid and gas are heated in the exchange line. This separation at low temperatures is represented by the abbreviation CB.
[0015] This carbon dioxide-depleted gas 1 nevertheless contains carbon dioxide, hydrogen, and nitrogen and / or methane and / or carbon monoxide.
[0016] Gas 1, at a pressure of 40-70 bara and a temperature of 0-50°C, is optionally heated in a heat exchanger E to a temperature of 60-100°C, more preferentially 65-90°C.
[0017] At this temperature and this pressure, without being otherwise heated, it is separated by permeation through the first membrane M1 at 15 to 30 bara, more particularly 17 to 25 bara, lower than the inlet pressure of the pressure swing adsorption hydrogen separation unit, to produce a first permeate P1 enriched in hydrogen and carbon dioxide relative to the mixture and depleted in nitrogen and / or carbon monoxide and / or methane relative to the mixture.
[0018] Thus, the first permeate P1 is compressed in a booster C1 to reach a pressure of 20 to 40 bara, more particularly 20 to 30 bara, sufficient to recycle it upstream of the PSA. All or part of the permeate can then be cooled in a heat exchanger E and sent to a pressure swing adsorption hydrogen separation unit to be separated.
[0019] The first retentate R1 of the first membrane, depleted of hydrogen and carbon dioxide and enriched in nitrogen and / or carbon monoxide and / or methane, is sent to the second membrane M2.
[0020] The pressure of the second permeate P2, enriched in hydrogen and carbon dioxide and depleted in nitrogen and / or carbon monoxide and / or methane, produced by the second membrane M2 is lower than the pressure of the stage of compressor C to which it is recycled, this pressure being between 4 and 11 bara, more particularly between 5 and 9 bara.
[0021] The second permeate P2 is therefore compressed in a second booster C2 to a pressure of 5 to 15 bara, more particularly 8 to 11 bara, in order to reach a pressure sufficient to recycle it to the upstream stage of the cryogenic separation in compressor C. All or part of the second permeate P2 can be cooled in a heat exchanger E and is preferably sent to the inlet of compressor C.
[0022] The second residue produced by the second membrane M2, depleted in hydrogen and carbon dioxide and enriched in nitrogen and / or carbon monoxide and / or methane, is expanded in at least one turbine, in which two turbines T1 and T2 in turn drive two boosters C1, C2, resulting in a gas at low pressure (3 to 5 bara) and a low temperature of -30 to -55°C.
[0023] This gas R2, expanded in two turbines T1, T2, can be used to regenerate the dryer upstream of the cold separation.
[0024] The following steps of the method described above are optional in nature: Heating the residue gas 1 originating from the separation by distillation and / or partial condensation through an exchanger E before the first membrane separation so as to reach a temperature between 60 and 100°C, more preferentially between 65 and 90°C. Cooling the first permeate P1 through an exchanger E before its compression to reach a temperature between 15 and 80° C. This step can be performed, as illustrated, by cooling only a portion 7 of the permeate P1 to a colder temperature (for example between 15 and 30° C.) and then combining it with the rest of the permeate. Cooling all or part of the gas at the outlet of the first booster C1 in a heat exchanger E before recycling it upstream of the PSA to reach a temperature in the range of 10 to 50°C, more specifically 20 to 40°C. Cooling the second permeate P2 via a heat exchanger E to reach a temperature of 10-50° C. This step can be performed by cooling only a portion 17 of the permeate to a cooler temperature (for example 15-30° C.) and then combining it with the rest of the hot permeate. cooling all or part of the gas at the outlet of the second booster in a heat exchanger E before recycling it upstream of the cryogenic separation to reach a temperature between 20 and 80°C, more specifically between 30 and 70°C; Sending the cold gas at the outlet of the second turbine T2 to the main exchanger of the cryogenic separation, where it cools the feed gas originating from the hydrogen (H2) production unit, which includes a pressure swing adsorption hydrogen separation unit.
[0025] The following variations are possible: Adding heaters downstream of turbines T1 and T2 to obtain hotter gases at the inlet of the turbines. In this case, the gases at the outlet of the second turbine are not sent to the deep cold section.
[0026] This arrangement makes it possible to reduce the pressure of the two permeates with a booster, for example by recycling the first to the PSA and the second to the same stage of the machine upstream of the cryogenic separation. Reducing the pressure of the permeates creates a higher pressure ratio between the two membranes, thus increasing the separation efficiency of the membranes.
[0027] The present invention can be used in two different ways: either by keeping the number of membranes constant (allowing for better CO and H yields to be obtained (at a small specific energy cost)) or by decreasing the number of membranes to obtain yields similar to the configuration without turbomachinery (in which case the specific CO capture energy is reduced).
[0028] The table below illustrates the yield difference between a membrane according to the invention and a membrane without a turbine driving a booster, using the same membrane surface area and the same composition at the inlet of the membrane.
[0029] In the first stage M1, the yields of H2 and CO2 are improved by 14% and 15%, respectively.
[0030] In the second stage M2, the yields of H2 and CO2 are improved by 6% and 10%, respectively.
[0031] [Table 1]
[0032] At least a portion of the second residue R2 expanded in at least one turbine T1, T2 is sent to a purification unit as regeneration gas, and / or at least a portion of the expanded second residue R2 is sent to an exchange line E to contribute cold, and / or at least a portion of the expanded second residue R2 is sent to the burner of a reformer, which can feed a PSA, the residue of which is gas sent to a compressor C.
Claims
1. Follow these steps: a) compression of a feed flow in a compressor (C) to form a carbon dioxide-rich stream and a mixture (1) containing mainly hydrogen, carbon dioxide, and at least one component selected from the list of carbon monoxide, methane, or nitrogen, dehydration purification of said feed flow in an adsorption purification unit and / or cooling of said dehydration purified stream in an exchange line, separation of said purified and / or said cooled feed flow by partial condensation and / or distillation, and b) the steps of: i) optionally heating said mixture (1) in a heat exchanger (E) to a temperature of 60-100°C; ii) permeation of said mixture (3), optionally heated, through a first membrane (M1), making it possible to obtain a first permeate (P1) enriched in hydrogen and carbon dioxide compared to said mixture, and a first retentate (R1) depleted in hydrogen and carbon dioxide compared to said mixture; iii) optionally cooling at least a portion of said first permeate in said heat exchanger; iv) compression of the optionally cooled first permeate in a first booster (C1); v) optionally cooling at least a portion of the first permeate compressed in the first booster in the heat exchanger; vi) permeation of said first retentate, preferably uncooled, through a second membrane, making it possible to obtain a second permeate (P2) enriched in hydrogen and carbon dioxide compared to said first retentate, and a second retentate (R2) depleted in hydrogen and carbon dioxide compared to said first retentate; vii) optionally cooling at least a portion of said second permeate in said heat exchanger; viii) compression of the optionally cooled second permeate in the second booster (C2); ix) optionally cooling at least a portion of said compressed second permeate in said heat exchanger; and x) expansion of said second residue in at least one turbine driving said first and / or said second booster; Separating said mixture by a membrane separation process comprising:
1. A process for the separation of a feed flow containing hydrogen, carbon dioxide, at least one component selected from the list of carbon monoxide, methane, or nitrogen, and optionally water, comprising:
2. 2. The process of claim 1, wherein at least a portion of the expanded second residue (R2) is sent to the purification unit as regeneration gas, and / or at least a portion of the expanded second residue is sent to the exchange line to contribute cold, and / or at least a portion of the expanded second residue is sent to a burner of a reformer.
3. 3. The process according to claim 1 or 2, wherein the mixture (3) is optionally heated in the heat exchanger (E) to a temperature of from 60 to 100°C.
4. 4. The process according to claim 3, wherein the mixture (1) is heated in the heat exchanger by indirect heat exchange with at least a portion of at least one of the following flows: first permeate (P1), first retentate (R1), second permeate (P2), second retentate (R2).
5. 5. The process according to any one of claims 1 to 4, wherein the second residue is expanded in two turbines (T1, T2) in sequence, each of which drives one of the first and second boosters (C1, C2).
6. 6. The process according to claim 5, wherein the residue (R2) expanded in the two turbines (T1, T2) is at a pressure of 3 to 5 bara and / or at a temperature of -30 to -55°C after expansion.
7. 7. The process according to any one of claims 1 to 6, wherein the feed flow is compressed in a compressor (C) upstream of the partial condensation and / or distillation (CB), and the second permeate (P2) compressed by the second booster (C2) is sent to the compressor to be compressed.
8. a compressor (C), a purification unit and / or an exchange line, means for sending the feed flow compressed by the compressor to the purification unit and / or to the exchange line, a separation unit of the purified and / or cooled feed flow by partial condensation and / or distillation (CB) to form a carbon dioxide-rich flow and a mixture (1) containing mainly hydrogen, carbon dioxide and at least one component selected from the list of carbon monoxide, methane or nitrogen, means for sending the feed flow from the purification unit and / or the exchange line to the separation unit, a first membrane (M1) and a duct for sending the mixture to be separated to the first membrane, making it possible to obtain a first permeate (P1) enriched in hydrogen and carbon dioxide compared to the mixture and a first retentate (R1) depleted in hydrogen and carbon dioxide compared to the mixture. a first booster (C1), a duct for sending the first permeate to the first booster to be compressed, a second membrane (M2), a duct for sending the first retentate, preferably uncooled, to the second membrane, which makes it possible to obtain a second permeate (P2) enriched in hydrogen and carbon dioxide compared to the first retentate and a second retentate (R2) depleted in hydrogen and carbon dioxide compared to the first retentate, a second booster (C2), a duct for sending the second permeate to the second booster, and at least one expansion turbine (T1, T2) connected to expand the second retentate to drive the first and / or second booster.
9. 9. Apparatus according to claim 8, comprising means for sending said second residue (R2) from said at least one expansion turbine (T1, T2) as regeneration gas to said purification unit.
10. 10. Apparatus according to claim 8 or 9, comprising means for sending said second residue (R2) from said at least one expansion turbine (T1, T2) to said exchange line (E) so as to contribute cold.
11. 11. Apparatus according to claim 8, 9 or 10, comprising means for sending said second residue (R2) from said at least one expansion turbine (T1, T2) to a burner of a reformer.
12. The apparatus of any one of claims 8 to 11, wherein the feed flow is residue gas from a pressure swing adsorption unit.
13. An apparatus according to any one of claims 8 to 12, comprising said purification unit and means for sending said feed flow compressed in said compressor (C) to said purification unit.
14. An apparatus according to any one of claims 8 to 11, comprising said exchange line (E) and means for sending said feed flow compressed in said compressor (C) to said exchange line.