Methods for co-electrolysis of water and CO2 (SOEC) or for high-temperature electricity production (SOFC) optionally promoting catalytic reactions inside the H2 electrode

Patent metadata

Field	Value
Publication number	US-11398640-B2
Application number	US-201716335524-A
Country	US
Kind code	B2
Filing date	Sep 15, 2017
Priority date	Sep 22, 2016
Publication date	Jul 26, 2022
Grant date	Jul 26, 2022

Abstract

The invention essentially consists of proposing a novel reactor or fuel cell architecture having an active section of the catalytic material for methanation or reforming reaction integrated into the electrode which varies with the composition of the gases, as they are distributed in accordance with the electrochemistry on said electrode.

First claim

The invention claimed is:

1. A method comprising co-electrolyzing steam H 2 O and carbon dioxide CO 2 , in a reactor comprising a stack of individual electrolysis cells of solid oxide type, with a rectangular or square area, each formed of a cathode comprising material configured to catalyze a methanation reaction, of an anode and of an electrolyte inserted between the cathode and the anode, a plurality of electrical and fluid interconnectors each comprising a first gas flow sector and a second gas flow sector arranged on a same side of the interconnector and each being arranged between two adjacent individual electrolysis cells of the stack of individual electrolysis cells with one face in electrical contact with the anode of one of the two adjacent individual electrolysis cells and the other face in electrical contact with the cathode of a second individual electrolysis cell of the two adjacent individual electrolysis cells, and a plurality of electrical contact and gas distribution elements, each arranged between the cathode of one of the individual electrolysis cells and one of the plurality of electrical and fluid interconnectors, wherein:
a first zone and a second zone of each of the plurality of electrical and fluid interconnectors are supplied independently with a mixture of steam H 2 O and of carbon dioxide CO 2 and the mixture is distributed to the cathode of each of the individual electrolysis cells, then a synthesis gas produced is recovered within the cathode of each of the individual electrolysis cell, in a third zone and a fourth zone of each of the plurality of electrical and fluid interconnectors in fluid communication respectively with the first zone and the second zone; each of the plurality of electrical contact and gas distribution elements integrating a sealing bead forming a gas distribution barrier separating the first gas flow sector comprising the first and third zones from the second gas flow sector comprising the second and fourth zones, the first gas flow sector and the second gas flow sector being adjoined by the gas distribution barrier, forming an area substantially equal to that of each cell; the first to fourth zones being dimensioned, and the gas circulation barrier being arranged, such that a length of the first gas flow sector in a direction perpendicular to a direction of gas flow increases or decreases between the first and third zones and a length of the second gas flow sector in a direction perpendicular to a direction of gas flow also increases or decreases between the second and fourth zones; and
the first and second zones of each of the plurality of electrical and fluid interconnectors are supplied such that a gas circulation to each cathode in the first flow sector is in counterflow to a gas circulation in the second flow sector.

2. The method of claim 1 , wherein the first gas flow sector and the second gas flow sector are of trapezoidal form.

3. The method of claim 2 , comprising in-situ methanation, wherein supply is carried out via a largest base of the first gas flow sector and of the second gas flow sector of trapezoidal form delimited respectively by the first and the third zone, in order to minimize an in-situ methanation reaction compared to a co-electrolysis reaction of steam H 2 O and carbon dioxide CO 2 within the stack of individual electrolysis cells.

4. The method of claim 2 , wherein supply is carried out via the smallest base of the first and second trapezoidal sectors delimited respectively by the first and the third zone, in order to maximize the in situ methanation reaction compared to the co-electrolysis reaction within the stack.

5. The method of claim 2 , comprising in-situ methanation, wherein a length ratio between small and large bases of the first gas flow sector and of the second gas flow sector of trapezoidal form is determined beforehand in order to promote or not promote an in-situ methanation reaction compared to a co-electrolysis reaction of steam H 2 O and carbon dioxide CO 2 within the stack of individual electrolysis cells.

6. The method of claim 1 , wherein a fifth zone of each electrical and fluid interconnector is supplied with draining gas, and it is distributed to the anode of each individual electrolysis cell, then the oxygen O 2 produced and the draining gas are recovered in a sixth zone of each interconnector, so as to have a same supply of draining gas and a same recovery of oxygen produced for the first gas flow sector and the second gas flow sector.

7. The method of claim 1 , comprising in-situ methanation, wherein the co-electrolysis is carried out at least in part with steam H 2 O produced by in-situ methanation.

Assignees

• Commissariat Energie Atomique

Inventors

• Reytier Magali
• Roux Guilhem
• Laurencin Jerome
• Planque Michel

Classifications

• Y02E60/50

  Fuel cells · CPC title

• Y02E60/36

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

• C25B3/25

  Reduction · CPC title

• C25B9/73

  of the filter-press type · CPC title

• H01M8/0202

  Collectors; Separators, e.g. bipolar separators; Interconnectors · CPC title