Electrolytic system

Abstract

The combustion temperature of the combustion section that burns off-gas is appropriately increased to improve system efficiency. [Solution] The device comprises a solid oxide type electrolytic cell, a combustion section that burns a mixture of combustion fuel gas and a combustion aid gas and discharges combustion exhaust gas, a heat-insulating case that houses the electrolytic cell and the combustion section, a condensation section provided outside the case that condenses water vapor in the hydrogen electrode off-gas discharged from the electrolytic cell, a combustion fuel gas flow path that supplies at least a portion of the hydrogen electrode off-gas that has passed through the condensation section to the combustion section as combustion fuel gas, a combustion aid gas flow path that supplies the oxygen electrode off-gas discharged from the electrolytic cell to the combustion section as a combustion aid gas, a first heat exchange section provided inside the case that exchanges heat between the gas supplied to the electrolytic cell and the combustion exhaust gas discharged from the combustion section, and a second heat exchange section provided inside the case that exchanges heat between the combustion fuel gas supplied to the combustion section via the combustion fuel gas flow path and the combustion exhaust gas that has passed through the first heat exchange section.

Claims

1. A solid oxide type electrolytic cell that receives a supply of gas containing water vapor to produce hydrogen and oxygen, and discharges a hydrogen electrode off-gas containing the produced hydrogen and unreacted water vapor, and an oxygen electrode off-gas containing the produced oxygen, A combustion section burns a mixture of combustion fuel gas and combustion aid gas, and discharges combustion exhaust gas. A case having thermal insulation properties, which houses the electrolytic cell and the combustion unit, A condensing unit provided outside the case for condensing water vapor in the hydrogen electrode off-gas discharged from the electrolytic cell, A combustion fuel gas flow path supplies at least a portion of the hydrogen electrode off-gas that has passed through the condensation section to the combustion section as the combustion fuel gas, A combustion-supporting gas channel for supplying the oxygen electrode off-gas discharged from the electrolytic cell as the combustion-supporting gas to the combustion section, A first heat exchange unit is provided within the case and exchanges heat between the gas supplied to the electrolytic cell and the combustion exhaust gas discharged from the combustion unit, A second heat exchange unit is provided within the case and exchanges heat between the combustion fuel gas supplied to the combustion unit via the combustion fuel gas flow path and the combustion exhaust gas that has passed through the first heat exchange unit. An electrolytic system equipped with the following features.

2. The first heat exchange unit exchanges heat between the gas supplied to the oxygen electrode of the electrolytic cell and the combustion exhaust gas discharged from the combustion unit. The electrolytic system according to claim 1.

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