2026 Volume 22 Issue 2 Pages 122-127
As a domestically produced green hydrogen production technology, the thermochemical hydrogen production reaction based on the sodium redox reaction is introduced. Sodium redox reaction is represented by a combination of a metal separation reaction (thermal reduction reaction), an oxygen generation reaction by hydrolysis, and a hydrogen generation reaction by the reaction between the separated metallic sodium and the sodium hydroxide obtained after hydrolysis. Among these, the metal separation reaction requires heat of about 400°C as the highest temperature. However, since the heat after the metal separation reaction can be used in a cascade, in principle, hydrogen can be produced with an efficiency of more than 50% of the heat input for the reaction. Green hydrogen production methods include electrolytic hydrogen using renewable energy, photocatalysis, and thermochemical hydrogen production using nuclear heat. In contrast, the thermochemical hydrogen production introduced in this literature can be continuously controlled by combining various relatively accessible waste heat sources with heat storage materials. This is expected to result in a large-scale and low-cost domestic hydrogen production technology.
