# US 8,771,637 B2 · Gas separation process for production of hydrogen by autothermal reforming of natural gas, with carbon dioxide recovery > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,771,637 B2 - Document ID: US8771637B2 - Status: Granted - Kind: B2 - Application number: 13/370,942 - Filed: 2012-02-10 - Published: 2012-06-07 - Granted: 2014-07-08 - Earliest claimed: 2012-02-10 - Assignees: Membrane Technology and Research, Inc. - Applicants: Nicholas P. Wynn; Douglas E Gottschlich; Haiqing Lin - Inventors: Nicholas P. Wynn; Douglas E Gottschlich; Haiqing Lin - Web page: https://patentgrep.com/patent/US8771637B2 ## CPC - C01B 3/382: Processes with two or more reaction steps, of which at least one is catalytic, e.g. steam reforming and partial oxidation - C01B 3/501: by diffusion - C01B 3/56: by contacting with solids; Regeneration of used solids - C01B 32/40: Carbon monoxide - C01B 32/50: Carbon dioxide - C01B 2203/0244: the reforming step being an autothermal reforming step, e.g. secondary reforming processes - C01B 2203/0405: Purification by membrane separation - C01B 2203/043: Regenerative adsorption process in two or more beds, one for adsorption, the other for regeneration - C01B 2203/0495: the impurity being water - C01B 2203/1241: Natural gas or methane - C01B 2203/146: At least two purification steps in series - C01B 2203/148: involving a recycle stream to the feed of the process for making hydrogen or synthesis gas - C01B 2203/86: Carbon dioxide sequestration - Y02P 30/00: Technologies relating to oil refining and petrochemical industry - C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C} - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract Disclosed herein is a process for the production of hydrogen by autothermal reforming of natural gas, with simultaneous recovery of carbon dioxide using carbon dioxide-selective membrane separation. Residual gas from the hydrogen and carbon dioxide recovery is recycled back to the autothermal reformer. ## Claims ### Claim 1 A gas separation process for production of hydrogen by autothermal reforming of natural gas, wherein the process comprises the following steps: (a) introducing natural gas, steam, and oxygen into an autothermal reformer, to produce a gas mixture comprising carbon dioxide, carbon monoxide, hydrogen, water vapor, and residual natural gas; (b) cooling the gas mixture to condense out water; (c) treating the resultant gas mixture to remove hydrogen, to produce a hydrogen product stream and a hydrogen-depleted gas mixture; (d) providing a membrane having a feed side and a permeate side, wherein the membrane is selective to carbon dioxide over hydrogen, carbon monoxide, and methane; (e) passing the hydrogen-depleted gas mixture across the feed side; (f) withdrawing from the permeate side a permeate stream that is enriched in carbon dioxide relative to the hydrogen-depleted gas mixture; (g) withdrawing from the feed side a residue stream that is depleted in carbon dioxide relative to the hydrogen-depleted gas mixture; and (h) passing the residue stream as a recycle stream back to the autothermal reformer as feedstock. ### Claim 2 (depends on 1) A process in accordance with claim 1, wherein the residue stream is treated to remove inerts prior to being passed as a recycle stream back to the autothermal reformer in step (h). ### Claim 3 (depends on 1) A process in accordance with claim 1, wherein step (c) comprises a pressure swing adsorption step. ### Claim 4 (depends on 1) A process in accordance with claim 1, wherein step (c) comprises a membrane-based separation step using membranes that are selectively permeable to hydrogen over carbon dioxide. ### Claim 5 (depends on 1) A process in accordance with claim 1, wherein the membrane has a selectivity to carbon dioxide over hydrogen of at least 6. ### Claim 6 (depends on 5) A process in accordance with claim 5, wherein the membrane has a selectivity to carbon dioxide over hydrogen of at least 10. ### Claim 7 (depends on 1) A process in accordance with claim 1, wherein the membrane has a carbon dioxide permeance of at least about 200 gpu. ### Claim 8 (depends on 1) A process in accordance with claim 1, wherein the hydrogen-depleted gas mixture is compressed and condensed to produce high-purity carbon dioxide prior to being passed across the feed side of the membrane. ### Claim 9 (depends on 1) A process in accordance with claim 1, wherein the carbon dioxide-enriched permeate stream is compressed and condensed to produce high-purity carbon dioxide. ### Claim 10 (depends on 1) A process in accordance with claim 1, wherein the process results in the production of at least 20% more hydrogen than a conventional autothermal reforming process. ### Claim 11 A gas separation process for production of hydrogen by autothermal reforming of natural gas, wherein the process comprises the following steps: (a) introducing natural gas, steam, and oxygen into an autothermal reformer, to produce a gas mixture comprising carbon dioxide, carbon monoxide, hydrogen, water vapor, and residual natural gas; (b) cooling the gas mixture to condense out water; (c) providing a membrane having a feed side and a permeate side, wherein the membrane is selective to carbon dioxide over hydrogen; (d) passing the gas mixture across the feed side; (e) withdrawing from the permeate side a permeate stream that is enriched in carbon dioxide relative to the gas mixture; (f) withdrawing from the feed side a residue stream that is depleted in carbon dioxide relative to the gas mixture; (g) treating the residue stream to remove hydrogen, to produce a hydrogen product stream and a hydrogen-depleted gas stream; and (h) passing the hydrogen-depleted gas stream as a recycle stream back to the autothermal reformer as feedstock. ### Claim 12 (depends on 11) A process in accordance with claim 11, wherein the hydrogen-depleted gas stream is treated to remove inerts prior to being passed as a recycle stream back to the autothermal reformer in step (h). ### Claim 13 (depends on 11) A process in accordance with claim 11, wherein step (g) comprises a pressure swing adsorption step. ### Claim 14 (depends on 11) A process in accordance with claim 11, wherein step (g) comprises a membrane-based separation step using membranes that are selectively permeable to hydrogen over carbon dioxide. ### Claim 15 (depends on 11) A process in accordance with claim 11, wherein the membrane has a selectivity to carbon dioxide over hydrogen of at least 6. ### Claim 16 (depends on 15) A process in accordance with claim 15, wherein the membrane has a selectivity to carbon dioxide over hydrogen of at least 10. ### Claim 17 (depends on 11) A process in accordance with claim 11, wherein the membrane has a carbon dioxide permeance of at least about 200 gpu. ### Claim 18 (depends on 11) A process in accordance with claim 11, wherein the gas mixture is compressed and condensed to produce high-purity carbon dioxide prior to being passed across the feed side of the membrane. ### Claim 19 (depends on 11) A process in accordance with claim 11, wherein the carbon dioxide-enriched permeate stream is compressed and condensed to produce high-purity carbon dioxide. ### Claim 20 (depends on 11) A process in accordance with claim 11, wherein the process results in the production of at least 20% more hydrogen than a conventional autothermal reforming process.