# US 10,245,551 B2 · Membrane technology for use in a power generation process > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,245,551 B2 - Document ID: US10245551B2 - Status: Granted - Kind: B2 - Application number: 15/066,771 - Filed: 2016-03-10 - Published: 2016-07-07 - Granted: 2019-04-02 - Earliest claimed: 2011-05-25 - Assignees: Membrane Technology and Research, Inc. - Applicants: Richard W Baker; Timothy C Merkel; Johannes G Wijmans - Inventors: Richard W Baker; Timothy C Merkel; Johannes G Wijmans - Web page: https://patentgrep.com/patent/US10245551B2 ## CPC - B01D 53/22: by diffusion (manufacturing semi-permeable membranes B01D67/00; form, structure or properties of semi-permeable membranes B01D69/00; material for semi-permeable membranes B01D71/00) - B01D 53/229: {Integrated processes (Diffusion and at least one other process, e.g. adsorption, absorption)} - B01D 53/62: Carbon oxides - F01K 5/00: Plants characterised by use of means for storing steam in an alkali to increase steam pressure, e.g. of Honigmann or Koenemann type - F01K 23/10: with exhaust fluid of one cycle heating the fluid in another cycle (F01K17/025 takes precedence) - F02C 3/34: with recycling of part of the working fluid, i.e. semi-closed cycles with combustion products in the closed part of the cycle - F02C 6/18: using the waste heat of gas-turbine plants outside the plants themselves, e.g. gas-turbine power heat plants (using waste heat as source of energy for refrigeration plants F25B27/02; using the waste heat of a gasturbine for steam generation or in a steam cycle see F01K23/10) - F23C 9/00: Combustion apparatus characterised by arrangements for returning combustion products or flue gases to the combustion chamber (fluidised bed combustion apparatus with means for recirculation of particles entrained from the bed F23C10/02; fluidised bed combustion apparatus with devices for removal and partial reintroduction of material from the bed F23C10/26) - B01D 2053/221: {Devices} - B01D 2256/22: Carbon dioxide - B01D 2257/102: Nitrogen - B01D 2257/104: Oxygen - B01D 2257/504: Carbon dioxide - B01D 2258/0283: Flue gases - F05D 2260/61: Removal of CO2 - F05D 2260/611: Sequestration of CO2 - F23L 2900/07001: Injecting synthetic air, i.e. a combustion supporting mixture made of pure oxygen and an inert gas, e.g. nitrogen or recycled fumes - Y02C 20/40: of CO2 - Y02E 20/16: Combined cycle power plant [CCPP], or combined cycle gas turbine [CCGT] - Y02E 20/18: Integrated gasification combined cycle [IGCC], e.g. combined with carbon capture and storage [CCS] - Y02E 20/32: Direct CO2 mitigation - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - F01K: STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES (gas-turbine or jet-propulsion plants F02; nuclear power plants, engine arrangements therein G21D) - F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00) - F23C: METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN {A CARRIER GAS OR} AIR (burners F23D) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS - F23L: SUPPLYING AIR OR NON-COMBUSTIBLE LIQUIDS OR GASES TO COMBUSTION APPARATUS IN GENERAL ({air-supply arrangements for fluent fuels F23C;} firebridges with means for feeding air or steam F23M3/04; baffles or shields with air supply passages F23M9/04); VALVES OR DAMPERS SPECIALLY ADAPTED FOR CONTROLLING AIR SUPPLY OR DRAUGHT IN COMBUSTION APPARATUS {(dampers and throat restrictors for open fire-places F24; air inlet valves for open fire fronts F24)}; INDUCING DRAUGHT IN COMBUSTION APPARATUS; TOPS FOR CHIMNEYS OR VENTILATING SHAFTS; TERMINALS FOR FLUES - Y02C: CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG] - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract Disclosed herein is a power generation process in which a portion of the carbon dioxide generated by gaseous fuel combustion is recycled back to the power generation process, either pre-combustion, post-combustion, or both. The power generation process of the invention may be a combined cycle process or a traditional power generation process. The process utilizes sweep-based membrane separation. ## Claims ### Claim 1 A process for controlling carbon dioxide exhaust from combustion of a gaseous fuel, comprising: (a) performing a combined cycle power generation process, comprising (i) performing a combustion step by combusting a mixture comprising a gaseous fuel and an oxygen-containing gas, thereby generating a combustor exhaust stream comprising carbon dioxide and nitrogen, (ii) routing the combustor exhaust stream as at least a portion of a working gas stream to a gas turbine, thereby generating electrical power and creating a turbine exhaust stream, (iii) withdrawing from the gas turbine a first portion of the turbine exhaust stream at a pressure higher than atmospheric pressure; (iv) routing the first portion of the turbine exhaust stream to a boiler, thereby generating steam and creating a first boiler exhaust stream, (v) routing the steam to a steam turbine, thereby generating additional electrical power; (b) routing the first boiler exhaust stream to a membrane-based carbon dioxide capture step, wherein the capture step comprises (i) providing a first membrane having a first feed side and a first permeate side, and being selectively permeable to carbon dioxide over nitrogen and to carbon dioxide over oxygen, (ii) passing the first boiler exhaust stream across the first feed side, (iii) withdrawing from the first permeate side a partially concentrated carbon dioxide first permeate stream, (iv) withdrawing from the first feed side a carbon dioxide-depleted first residue stream; (c) routing the first residue stream to a sweep-based membrane separation step, wherein the sweep-based membrane separation step comprises (i) providing a second membrane having a second feed side and a second permeate side, and being selectively permeable to carbon dioxide over nitrogen and to carbon dioxide over oxygen, (ii) passing the first residue stream across the second feed side, (iii) passing air, oxygen-enriched air, or oxygen as a sweep stream across the second permeate side, (iv) withdrawing from the second feed side a second residue stream that is depleted in carbon dioxide compared to the feed gas, (v) withdrawing from the second permeate side a second permeate stream comprising oxygen and carbon dioxide; (d) passing the second permeate stream back to the power generation process; (e) passing the second residue stream to an expander unit, (f) withdrawing from the gas turbine a second portion of the turbine exhaust stream at approximately atmospheric pressure; (g) routing the second portion of the turbine exhaust stream to the boiler, thereby generating steam and creating a second boiler exhaust stream; and (h) routing the second boiler exhaust stream back to the power generation process as a recycle gas stream. ### Claim 2 (depends on 1) The process of claim 1, wherein the first portion of the turbine exhaust stream is withdrawn at a pressure within the range of about 2 bar to about 5 bar. ### Claim 3 (depends on 1) The process of claim 1, wherein at least a portion of the second permeate stream is routed back to the power generation process prior to the combustion step, as part of the oxygen-containing gas provided to the combustion step. ### Claim 4 (depends on 1) The process of claim 1, wherein the oxygen-containing gas provided to the combustion step comprises at least 15 volume % oxygen. ### Claim 5 (depends on 1) The process of claim 1, wherein the combustor exhaust stream comprises at least 2 volume % oxygen. ### Claim 6 (depends on 1) The process of claim 1, wherein the process recovers at least 80 volume % of the carbon dioxide generated by the combustion step into a partially concentrated carbon dioxide product stream. ### Claim 7 (depends on 6) The process of claim 6, wherein the partially concentrated carbon dioxide product stream contains at least 20 volume % carbon dioxide. ### Claim 8 (depends on 1) The process of claim 1, wherein the first membrane exhibits a selectivity for carbon dioxide over oxygen of at least 10. ### Claim 9 (depends on 1) The process of claim 1, wherein the second membrane exhibits a selectivity for carbon dioxide over oxygen of at least 10.