# US 2019/0169759 A1 · Solid oxide electrochemical gas separator inerting system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0169759 A1 - Document ID: US20190169759A1 - Status: Published application - Kind: A1 - Application number: 16/268,222 - Filed: 2019-02-05 - Published: 2019-06-06 - Earliest claimed: 2015-12-15 - Assignees: Hamilton Sundstrand Corporation - Applicants: Hamilton Sundstrand Corporation - Inventors: David E. Tew; Stephen E. Tongue; Jonathan Rheaume - Web page: https://patentgrep.com/patent/US20190169759A1 ## CPC - C25B 9/23: comprising ion-exchange membranes in or on which electrode material is embedded - B01D 53/326: {in electrochemical cells} - B64D 37/32: Safety measures not otherwise provided for, e.g. preventing explosive conditions - C25B 1/02: Hydrogen or oxygen - C25B 9/015: Cylindrical cells - C25B 9/70: Assemblies comprising two or more cells - C25B 11/069: consisting of at least one single element and at least one compound; consisting of two or more compounds - C25B 13/04: characterised by the material - C25B 13/07: based on ceramics - C25B 15/02: Process control or regulation - C25B 15/021: of heating or cooling - C25B 15/08: Supplying or removing reactants or electrolytes; Regeneration of electrolytes - C25B 15/083: {Separating products} - B01D 2256/10: Nitrogen - B01D 2257/104: Oxygen - B01D 2259/4575: in aeroplanes or space ships - Y02P 20/129: Energy recovery, e.g. by cogeneration, H2recovery or pressure recovery turbines - Y02T 50/40: Weight reduction - C25B: ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR (anodic or cathodic protection C23F13/00; single-crystal growth C30B) - 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) - B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract An air inert gas generating system consists of heat exchangers, a heating element, and a plurality of solid oxide electrochemical gas separator (SOEGS) cells. The SOEGS cells are interconnected in series to create a stack. A voltage is applied to the stack causing oxygen ions to be transported from the air flowing through the cathode through the electrolyte to the anode side of the SOEGS, resulting in oxygen-depleted gas. The oxygen-depleted gas can be used to inert the ullage of aircraft fuel tank or support the fire suppression system in the cargo hold. The oxygen-enriched gas can be used for other purposes. ## Claims ### Claim 1 An electrochemical gas separation system comprising: an inlet configured to port incoming process air; a plurality of solid oxide electrochemical gas separator cells, each comprising: a cathode configured for receiving heated process air; an anode configured for receiving oxygen ions; an electrolyte comprising an oxygen ion conductor, the electrolyte configured to transport oxygen ions reduced from the process air at the cathode when a bias voltage is applied from the anode to the cathode; a plurality of interconnectors, wherein each of the interconnectors is configured to electrically link each of the plurality of solid oxide electrochemical gas separator cells in series; a plurality of end portions, wherein each end portion is adjacent to one of the plurality of cells; a power source configured to apply a bias voltage across the plurality of solid oxide electrochemical gas separator cells; and an outlet configured to release oxygen-depleted air. ### Claim 2 (depends on 1) The electrochemical gas separation system of claim 1, further comprising: a cathode heat recovery heat exchanger that comprises: a cold side configured to receive and heat process air; and a hot side configured to receive and cool oxygen-depleted air from the plurality of solid oxide electrochemical gas separator cells; and an anode heat recovery heat exchanger that comprises: a cold side configured to receive and heat process air from the cathode heat recovery heat exchanger; and a hot side configured to receive and cool oxygen-enriched air. ### Claim 3 (depends on 1) The electrochemical gas separation system of claim 1, wherein the incoming process air is selected from the group consisting of engine bleed air, compressed air, ram air, cabin air, and fan air. ### Claim 4 (depends on 1) The electrochemical gas separation system of claim 1, wherein the cathode and the anode materials are selected from the group consisting of ceramic materials or noble metals supported on ceramic substrates. ### Claim 5 (depends on 1) The electrochemical gas separation system of claim 1, wherein the plurality of solid oxide electrochemical gas separator cells are each planar in shape, and are arranged in one or more crossflow stacks which are interconnected. ### Claim 6 (depends on 1) The electrochemical gas separation system of claim 1, wherein the plurality of solid oxide electrochemical gas separator cells are each tubular in shape, and are arranged in one or more stacks which are interconnected. ### Claim 7 (depends on 1) The electrochemical gas separation system of claim 1, further comprising a heating element, wherein the heating element may consist of electrical heaters configured to heat process air or a burner configured to receive and heat oxygen-enriched air from the plurality of solid oxide electrochemical gas separator cells through the burning of fuel. ### Claim 8 (depends on 1) The electrochemical gas separation system of claim 1, further comprising an element configured to pressurize process air, wherein the element consists of a motor-assisted turbocharger or a compressor. ### Claim 9 A method for inerting air, the method comprising: temperature-conditioning incoming process air; flowing the process air through a plurality of solid oxide electrochemical gas separator cells, each having a cathode configured for receiving the process air, an anode configured for receiving oxygen ions, and an electrolyte comprising an oxygen ion conductor, the electrolyte configured to reduce oxygen from the process air when a bias voltage is applied from the anode to the cathode; selectively routing resulting oxygen-enriched air out of the plurality of solid oxide electrochemical gas separator cells; temperature-conditioning the oxygen-enriched air; routing the oxygen-enriched air to an outlet; selectively routing resulting oxygen-depleted air out of the plurality of solid oxide electrochemical gas separator cells; temperature-conditioning outgoing oxygen-depleted air; and flowing the temperature-conditioned oxygen-depleted air to a second location. ### Claim 10 (depends on 9) The method of claim 9, further comprising: routing incoming process air into a first side of a cathode heat recovery heat exchanger, wherein the first side is configured to heat the process air; selectively routing the heated process air from the first side of the cathode heat recovery heat exchanger to a first side of an anode heat recovery heat exchanger, where the first side is configured to heat the air; flowing the heated process air from the first side of the anode heat recovery heat exchanger through the plurality of solid oxide electrochemical gas separator cells, selectively routing resulting oxygen-depleted air from the plurality of solid oxide electrochemical gas separator cells through a second side of the cathode heat recovery heat exchanger, wherein the second side is configured to cool the air; flowing the cooled oxygen-depleted air out of the second side of the cathode heat recovery heat exchanger to a second location; selectively routing resulting oxygen-enriched air to a second side of the anode heat recovery heat exchanger, wherein the second side is configured to cool the air; and flowing the cooled oxygen-enriched air from the second side of the anode heat recovery heat exchanger to an outlet. ### Claim 11 (depends on 9) The method of claim 9, wherein the process air is heated to at least 500 degrees Celsius and no more than 1100 degrees Celsius while exiting the cathode heat recovery heat exchanger. ### Claim 12 (depends on 9) The method of claim 9, further comprising routing the heated process air through a bypass valve downstream of the first side of the cathode heat recovery heat exchanger, wherein the bypass valve is configured to allow heated process air to flow into the first side of the anode heat recovery heat exchanger, or alternatively to flow directly to the plurality of solid oxide electrochemical gas separator cells. ### Claim 13 (depends on 9) The method of claim 9, further comprising flowing the heated process air through at least one electrical heater upstream of the plurality of solid oxide electrochemical gas separator cells. ### Claim 14 (depends on 9) The method of claim 9, further comprising flowing the heated process air through at least one flow control valve upstream of the plurality of solid oxide electrochemical gas separator cells. ### Claim 15 (depends on 9) The method of claim 9, further comprising: reducing oxygen molecules in the heated process air entering the cathode of the plurality of solid oxide electrochemical gas separator cells; conducting resulting oxygen ions across the electrolyte to the anode; recombining the oxygen ions into oxygen molecules in the anode; and expelling the oxygen molecules from the anode in the resulting oxygen-enriched air stream. ### Claim 16 (depends on 9) The method of claim 9, further comprising: routing the oxygen-enriched air from the anode of the plurality of solid oxide electrochemical gas separator cells to a burner configured to heat the oxygen-enriched air through the combustion of fuel. ### Claim 17 (depends on 9) The method of claim 9, wherein the oxygen-depleted air being routed to the second location is cooled to 80 degrees Celsius or lower. ### Claim 18 (depends on 9) The method of claim 9, wherein the second location is the ullage of a fuel tank. ### Claim 19 (depends on 9) The method of claim 9, wherein the second location is a fire suppression system.