System for high-temperature reversible electrolysis of water comprising a hydride tank coupled with the electrolyser

Patent metadata

Field	Value
Publication number	US-2019245224-A1
Application number	US-201716333299-A
Country	US
Kind code	A1
Filing date	Sep 18, 2017
Priority date	Sep 19, 2016
Publication date	Aug 8, 2019
Grant date	—

Abstract

A system for high-temperature reversible electrolysis of water, characterised in that it includes: a high-temperature reversible electrolyser, configured to operate in SOEC (solid oxide electrolyser cell) mode to produce hydrogen and store electricity, and/or in SOFC (solid oxide fuel cell) mode to withdraw hydrogen and produce electricity; a hydride tank, thermally coupled with the reversible electrolyser, the system being configured to allow the recovery of heat released by the hydride tank during hydrogen absorption in order to produce pressurised steam intended for entering the reversible electrolyser in SOEC mode, and to allow the recovery of heat released by the one or more outgoing streams from the reversible electrolyser in SOFC mode so as to allow the desorption of hydrogen from the hydride tank.

First claim

What is claimed is:

1 . System for high-temperature reversible electrolysis of water comprising:
a device forming a high-temperature reversible electrolyser, configured to operate in a solid-oxide electrolyser mode, for the production of hydrogen and thus the storage of electricity, and/or according to a solid-oxide fuel cell mode, for the consumption of hydrogen and thus the withdrawal of electricity, said reversible electrolyser being configured to operate under a pressure of between 2 and 15 bars, a hydride tank, thermally coupled with said reversible electrolyser, configured to store hydrogen in the form of hydrides in solid-oxide electrolyser mode of said reversible electrolyser and/or to release hydrogen in solid-oxide fuel cell mode of said reversible electrolyser, the system being configured to allow, when the reversible electrolyser is configured to operate in a solid-oxide electrolyser mode, a recovery of the heat released by the hydride tank during the absorption of hydrogen in order to produce pressurized steam intended to enter the reversible electrolyser, and to allow, when the reversible electrolyser is configured to operate in a solid-oxide fuel cell mode, a recovery of the heat released by the streams leaving the reversible electrolyser to enable the desorption of hydrogen from the hydride tank.

2 . System according to claim 1 , wherein the reversible electrolyser comprises a stack of basic solid-oxide electrochemical cells each formed by a cathode, an anode, and an electrolyte inserted between the cathode and the anode, and a plurality of electrical and fluidic interconnectors each arranged between two adjacent basic cells.

3 . System according to claim 1 , wherein the reversible electrolyser is configured to operate in a solid-oxide electrolyser mode, and the system then comprises:
a steam generator, intended to produce steam for the reversible electrolyser by means of the heat released by the hydride tank, during absorption of the hydrogen, and supplied to the steam generator by means of a heat transfer fluid.

4 . System according to claim 3 , wherein it also comprises:
one or more heat exchangers allowing the water at the inlet of the system to be preheated and/or the steam entering the reversible electrolyser to be superheated, by means of the hydrogen and oxygen streams leaving the reversible electrolyser.

5 . System according to claim 4 , wherein it comprises heat exchangers upstream and downstream of the steam generator for allowing the water at the inlet of the system to be preheated and the steam entering the reversible electrolyser to be superheated, respectively, by means of the hydrogen and oxygen streams leaving the reversible electrolyser.

6 . System according to claim 3 , wherein it also comprises:
a condenser, coupled to a phase separator, intended to receive the unreacted steam in the reversible electrolyser and the dihydrogen produced by the reversible electrolyser and to condense the unreacted water so that it can be recycled in the system.

7 . System according to claim 3 , wherein it also comprises:
a compression pump, intended to compress the water at the inlet of the system to a pressure of between 2 and 15 bars.

8 . System according to claim 3 , wherein it also comprises:
an electrical heating element upstream of the reversible electrolyser, providing an additional superheating of the steam.

9 . System according claim 6 , wherein it also comprises:
a dryer, upstream of the hydride tank and downstream of the phase separator, intended to allow the humidity contained in the dihydrogen to be removed before storage in the hydride tank.

10 . System according to claim 1 , wherein the reversible electrolyser is configured so as to operate in a pressurized solid-oxide fuel cell mode, and wherein the system then comprises:
at least one heat exchanger, intended to preheat at least one stream entering the reversible electrolyser by means of at least one stream leaving the reversible electrolyser.

11 . System according to claim 1 , wherein the reversible electrolyser is configured to operate in a solid-oxide fuel cell mode, and wherein the system then comprises:
at least one heat exchanger, intended to recover the high-temperature heat coming from at least one stream leaving the reversible electrolyser by means of at least one heat transfer fluid.

12 . System according to claim 1 , wherein the reversible electrolyser is configured to operate in a solid-oxide fuel cell mode, and wherein the system is a “compressed air recirculation system”, consisting of a dihydrogen circuit and a primary air circuit.

13 . System according to claim 1 , wherein the reversible electrolyser is configured to operate in a solid-oxide fuel cell mode, and wherein the system is a “three-stream system”, consisting of a dihydrogen circuit, a primary air circuit and a cooling circuit using a “three-stream” interconnector.

14 . System according to claim 12 , wherein the dihydrogen circuit comprises:
means for mixing the hydrogen coming from the hydride tank with the total recycling of the unconsumed hydrogen in the reversible electrolyser over a pressure range of 2 to 15 bars, a heat exchanger, intended to preheat the dihydrogen stream entering the reversible electrolyser by means of the dihydrogen stream leaving the reversible electrolyser, a heat exchanger, forming a heat recovery element, intended to recover high-temperature heat from the dihydrogen stream leaving the reversible electrolyser by means of at least one heat transfer fluid.

15 . System according to claim 14 , wherein it also comprises a heat exchanger, intended to cool the dihydrogen stream leaving the heat exchanger, forming a heat recovery element, by the hydrogen stream leaving a phase separator, allowing for recovery of the water produced.

16 . System according to claim 12 , wherein the primary air circuit comprises:
a heat exchanger, intended to preheat the air stream entering the reversible electrolyser by means of the air stream leaving the reversible electrolyser, a heat exchanger, forming a heat recovery element, intended to recover high-temperature heat coming from the air stream leaving the reversible electrolyser by means of at least one heat transfer fluid.

17 . System according to claim 16 , wherein it also comprises means for mixing the air stream leaving the heat exchanger, forming a heat recovery element, with supplemental oxygen forming a total stream of air entering the reversible electrolyser.

18 . System according to claim 17 , wherein it also comprises:
a heat exchanger and a cooling device, making it possible to cool the total air stream mixed by mixing means, a compression pump, making it possible to compress the air leaving the cooling device before injection into the heat exchanger in order to preheat it.

19 . System according to claim 13 , wherein the primary air circuit comprises:
a heat exchanger, intended to preheat the air stream entering the reversible electrolyser by means of the air stream leaving the reversible electrolyser, a heat exchanger, forming a heat recovery element, intended to recover coming from the air stream leaving the reversible electrolyser by means of at least one heat transfer fluid.

20 . System according to claim 13 , wherein the cooling circuit comprises:
a heat exchanger, intended to preheat the stream entering the reversible electrolyser by means of the hot stream leaving the reversible electrolyser, a heat exchanger, forming a h

Assignees

• Commissariat Energie Atomique

Inventors

• Lacroix Vincent
• Chaise Albin
• Cren Julie
• Reytier Magali
• Roux Guilhem

Classifications

• H01M8/186

  by electrolytic decomposition of the electrolytic solution or the formed water product · CPC title

• H01M2008/1293

  Fuel cells with solid oxide electrolytes · CPC title

• H01M8/04014

  Heat exchange using gaseous fluids; Heat exchange by combustion of reactants · CPC title

• H01M8/04216 Primary

  characterised by the choice for a specific material, e.g. carbon, hydride, absorbent · CPC title

• Y02P20/129

  Energy recovery, e.g. by cogeneration, H2recovery or pressure recovery turbines · CPC title