US 11,053,599 B2
Process for starting mode or stand-by mode operation of a power-to-gas unit comprising a plurality of high-temperature electrolysis (SOEC) or co-electrolysis reactors
Aymeric Brunot, Corenc (FR); and Vincent Lacroix, Grenoble (FR)
Assigned to COMMISSARIAT A L'ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES, Paris (FR)
Filed by COMMISSARIAT A L'ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES, Paris (FR)
Filed on Dec. 20, 2018, as Appl. No. 16/227,252.
Claims priority of application No. 17 62904 (FR), filed on Dec. 22, 2017.
Prior Publication US 2019/0194816 A1, Jun. 27, 2019
Int. Cl. C25B 15/08 (2006.01); C25B 1/00 (2021.01); C25B 1/04 (2021.01); C25B 3/25 (2021.01); C25B 9/65 (2021.01); C25B 9/73 (2021.01); C25B 11/031 (2021.01); C25B 11/069 (2021.01); C25B 3/00 (2021.01); C25B 15/02 (2021.01); C10L 3/08 (2006.01)
CPC C25B 15/08 (2013.01) [C25B 1/00 (2013.01); C25B 1/04 (2013.01); C25B 3/00 (2013.01); C25B 3/25 (2021.01); C25B 9/65 (2021.01); C25B 9/73 (2021.01); C25B 11/031 (2021.01); C25B 11/069 (2021.01); C25B 15/02 (2013.01); C10L 3/08 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A process for operating in starting mode or in stand-by mode a unit, termed power-to-gas unit, comprising a number N of reactors with a stack of solid oxide (SOEC) type elemental electrolysis cells, the cathodes of which are made of methanation reaction catalyst material(s),
wherein, when it is desired to carry out an increase in temperature of the N reactors or of a fraction thereof, or when a level of available electricity is insufficient to carry out a high-temperature electrolysis (HTE) or a co-electrolysis of H2O and CO2 within all of the N reactors, the process comprises the following steps:
a/ a number P of reactors are supplied with electricity and, if required, with heat, and either steam H2O, or a mixture of steam and carbon dioxide CO2 is supplied and distributed to the cathodes of the P reactors so as to carry out, at each cathode of the P reactors, either a high-temperature electrolysis (HTE) of the steam H2O, or a high-temperature co-electrolysis of steam and carbon dioxide,
b/ at least one part of the gases resulting from the electrolysis (hydrogen H2, steam H2O) or from the co-electrolysis (H2, steam, carbon monoxide CO, carbon dioxide CO2, methane CH4) is recovered and is supplied and distributed to each cathode of a number X of reactors not supplied with electricity, the number X being less than or equal to N-P, so as to carry out, at each cathode of the X reactors, a methanation by heterogeneous catalysis.