Development and Demonstration of Large-scale Alkaline Water Electrolysis System “Aqualyzer” (Supporting Information)

The shift towards low-carbon hydrogen via water electrolysis using renewable electricity is crucial for reducing greenhouse gas (GHG) emissions across various industrial sectors. Asahi Kasei, a Japanese chemical company, has leveraged its extensive chlor-alkali electrolysis expertise to develop and demonstrate a large-scale alkaline water electrolysis system, the “Aqualyzer.” This paper provides an overview of the core technologies developed for Aqualyzer, including advanced electrolysis components, dynamic control methods, and system simulation technologies. It also details the key test and demonstration facilities, specifically the 10 MW-class system deployed at the Fukushima Hydrogen Energy Research Field (FH2R) and the alkaline water electrolysis pilot test plant comprising four modules in Kawasaki, Japan.