Process water gas management of electrolyzer system with membrane

Patent metadata

Field	Value
Publication number	US-2021101034-A1
Application number	US-201916593834-A
Country	US
Kind code	A1
Filing date	Oct 4, 2019
Priority date	Oct 4, 2019
Publication date	Apr 8, 2021
Grant date	—

Abstract

A system and method fare disclosed for inerting a protected space. Process water is delivered to an anode of an electrochemical cell where a portion of the process water is electrolyzed to form protons and oxygen. The protons are transferred across the separator to the cathode, and process water is directed through a process water fluid flow path including a first side of a membrane. Gas is transferred to a second side of the membrane to form a de-gassed process water on the first side of the membrane, and the de-gassed process water is recycled to the anode. Air is delivered to the cathode and oxygen is reduced at the cathode to generate oxygen-depleted air. The oxygen-depleted air is directed from the cathode of the electrochemical cell along an inerting gas flow path to the protected space.

First claim

What is claimed is:

1 . A system for providing inerting gas to a protected space, comprising:
an electrochemical cell comprising a cathode and an anode separated by a separator comprising a proton transfer medium; a power source arranged to provide a voltage differential between the anode and the cathode; a cathode fluid flow path in operative fluid communication with the cathode between a cathode fluid flow path inlet and a cathode fluid flow path outlet; an anode fluid flow path in operative fluid communication with the anode, between an anode fluid flow path inlet and an anode fluid flow path outlet; a cathode supply fluid flow path between an air source and the cathode fluid flow path inlet, and an inerting gas flow path in operative fluid communication with the cathode fluid flow path outlet and the protected space; an anode supply fluid flow path between a process water source and the anode fluid flow path inlet; a process water fluid flow path in operative fluid communication with the anode fluid flow path inlet and the anode fluid flow path outlet; and a membrane including a first side in operative fluid communication with the process water fluid flow path and a second side in operative fluid communication with a first gas outlet.

2 . The system of claim 1 , wherein a fluid pressure on the second side of the membrane is lower than a fluid pressure on the first side of the membrane.

3 . The system of claim 2 , further including a vacuum pump in operative fluid communication with the second side of the membrane.

4 . The system of claim 3 , wherein the vacuum pump is an oil-free vacuum pump.

5 . The system of claim 3 , wherein the vacuum pump is a diaphragm vacuum pump, a rocking piston vacuum pump, a scroll vacuum pump, a roots vacuum pump, a parallel screw vacuum pump, a claw type vacuum pump, or a rotary vane vacuum pump.

6 . The system of claim 2 , further including an ejector suction port in operative fluid communication with the second side of the membrane.

7 . The system of claim 2 , wherein the pressure on the second side of the membrane is provided by a fluid connection operable to provide fluid communication with ambient air at an altitude greater than 10,000 feet above sea level.

8 . The system of claim 1 , further comprising a sweep gas flow path on the second side of the membrane in operative fluid communication with a source of a sweep gas.

9 . The system of claim 1 , wherein the membrane includes a micro-porous structure with pore or path sizes configured to be have greater permeability to gas molecules than to water molecules.

10 . The system of claim 1 , wherein the membrane includes a polymer configured to have greater affinity with gas molecules than water molecules.

11 . The system of claim 1 , further comprising a liquid-gas separator on the process water fluid flow path, wherein the liquid-gas separator includes an inlet and a liquid outlet each in operative fluid communication with the process water fluid flow path, and a second gas outlet.

12 . The system of claim 1 , further comprising a heater or a first heat exchanger including a heat absorption side in operative fluid communication with the process water fluid flow path.

13 . The system of claim 12 , further comprising a second heat exchanger including a heat rejection side in operative fluid communication with the process water fluid flow path and a heat absorption side in operative thermal communication with a heat sink.

14 . The system of claim 1 , comprising a plurality of said electrochemical cells in a stack separated by electrically-conductive fluid flow separators.

15 . The system of claim 1 , further comprising:
a sensor configured to directly or indirectly measure dissolved oxygen content of process water that enters the gas-liquid separator; a controller configured to provide a target response of the sensor through operation and control of fluid conditions at the membrane.

16 . A method of inerting a protected space, comprising:
delivering process water to an anode of an electrochemical cell comprising an anode and a cathode separated by a separator comprising a proton transfer medium; electrolyzing a portion the process water at the anode to form protons and oxygen; transferring the protons across the separator to the cathode; delivering air to the cathode and reducing oxygen at the cathode to generate oxygen-depleted air; directing the process water through a process water fluid flow path including a a first side of a membrane; transporting gas from the process water fluid flow path on the first side of the membrane to a second side of the membrane to form a de-gassed process water on the first side of the membrane, and recycling the de-gassed process water to the anode; and directing the oxygen-depleted air from the cathode of the electrochemical cell along an inerting gas flow path to the protected space.

17 . The method of claim 16 , further comprising transporting a sweep gas along the second side of the membrane.

18 . The method of claim 16 , further comprising applying a pressure differential across the membrane with a lower pressure on the second side of the membrane compared to pressure on the first side of the membrane.

19 . The method of claim 18 , wherein applying a pressure differential between the first and second sides of the membrane includes:
providing the second side of the membrane with operative fluid communication with ambient air at an altitude greater than 10,000 feet above sea level to provide the pressure differential, or operating a vacuum pump on the second side of the membrane, or delivering a motive fluid to an ejector that includes a suction port in operative fluid communication with the second side of the membrane, or a combination including any of the foregoing.

20 . The method of claim 18 , further comprising controlling the pressure differential between the first and second sides of the membrane to provide a target level of dissolved oxygen in the process water.

Assignees

• Hamilton Sundstrand Corp

Inventors

• Rheaume Jonathan
• Cocks Peter At

Classifications

• C25B15/083

  Separating products · CPC title

• Y02E60/36

  Hydrogen production from non-carbon containing sources, e.g. by water electrolysis · CPC title

• B64D2045/009

  Fire detection or protection; Erosion protection, e.g. from airborne particles · CPC title

• A62C3/08 Primary

  in aircraft {(A62C3/0207 takes precedence)} · CPC title

• C25B1/04 Primary

  by electrolysis of water · CPC title