Method and apparatus for producing hydrogen

Abstract

An electrolyzer structure is provided that is suitable for use in a method that produces hydrogen by steam electrolysis by feeding reducing gas to an anode side and feeding steam to a cathode side of an electrolyzer that is partitioned into the anode side and the cathode side by a diaphragm of solid oxide electrolyte, and feeding power to the anode and cathode of the electrolyzer. One embodiment of the present invention relates to an apparatus that produces hydrogen by high temperature steam electrolysis and that comprises an electrolyzer partitioned into an anode side and a cathode side by a solid oxide electrolyte diaphragm, a conduit that feeds reducing gas to the anode side of the electrolyzer, and a conduit that feeds steam to the cathode of the electrolyzer, in which a metal cermet stable in a reducing atmosphere is used as the material of the anode and the cathode. Another embodiment of the present invention relates to a method of producing hydrogen by high temperature steam electrolysis for reducing electrolysis voltage by feeding steam to a cathode side and feeding hydrocarbon-containing gas to an anode side for reaction with oxygen ion, the cathode side and the anode side being provided in a high temperature steam electrolytic apparatus in which an electrolyzer is partitioned into the anode side and the cathode side using a solid oxide electrolyte as the diaphragm, wherein offgas discharged from the anode side of the electrolytic apparatus is admixed into the hydrocarbon-containing gas that is fed to the anode side of the electrolytic apparatus.

Description

TECHNICAL FIELD [0001] The present invention relates to a method and apparatus for producing hydrogen by high temperature steam electrolysis. More particularly, the present invention relates to an electrolytic apparatus suitable for use in an electrolytic method that reduces the power required by electrolysis by carrying out electrolysis by feeding steam to a cathode side and reducing gas to an anode side of an electrolytic apparatus in which the electrolyzer is partitioned into the anode side and the cathode side by a solid oxide electrolyte diaphragm. BACKGROUND ART [0002] Methods for the electrolysis of water for the purpose of producing hydrogen include alkaline water electrolysis, solid polymer water electrolysis, and high temperature steam electrolysis. However, because alkaline water electrolysis and solid polymer water electrolysis require an electrolysis voltage of at least 1.8 V, their electrical efficiency is no greater than 80% and they require large amounts of electrica...

AI Technical Summary

Benefits of technology

The present invention relates to a method and apparatus for producing hydrogen by high temperature steam electrolysis using a solid oxide electrolyte diaphragm to partition the electrodes. This method reduces the power required for hydrogen production by carrying out electrolysis at high temperatures. The invention provides an electrolyzer structure that is adapted for use in this method, including a conduit for feeding reducing gas to the anode side and a conduit for supplying steam to the cathode side. The technical effects of the invention include reducing the electrical power required for hydrogen production and achieving a substantial reduction in electrical power consumption.

Problems solved by technology

However, because alkaline water electrolysis and solid polymer water electrolysis require an electrolysis voltage of at least 1.8 V, their electrical efficiency is no greater than 80% and they require large amounts of electrical power for hydrogen production.

However, neither an electrolyzer nor process conditions adapted to these circumstances have appeared.

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