Direct seawater electrolysis technology for hydrogen production

Hydrogen has high potential as alternative fuel and chemical feedstock. In 2022 the low-emission hydrogen production was less than 1 percent of the global hydrogen production, whereas the major part of hydrogen was being produced from fossil fuels. Many projects on green hydrogen production by electrolysis are in their development phase with a goal to reach 38Mt of low-emission hydrogen production per year by 2030. 

Electrolysis, which is an electrochemical splitting of water to hydrogen and oxygen, requires water of ultra high purity to avoid quick degradation of electrolyser components, which makes the whole process expensive. Instead, it would be more profitable to use seawater which represents 96 percent of the global water supply.

SWEETHY is a new European project which will study this possibility, the development of advanced technology for seawater electrolysis. Besides production of hydrogen, the project will also study oxygen production as well as the formation of other byproducts, and will couple the electrolysis to renewable energy sources, such as wind and photovoltaics. SWEETHY will focus on three main directions: development and optimisation of electrolyser materials (and components), development of a new type of electrolyser stack architecture for the anion-exchange membrane water electrolyser (AEMWE) with hydraulic cell compression, and sustainability analysis studies for the electrolyser system and its integration into renewable-power systems.

RISE coordinates this European project and also leads a work package on electrolyser configuration. This is an intermediate stage between the ready component development and the beginning of prototype development of the new electrolyser architecture. SWEETHY gathers nine partners from seven countries in Europe: Sweden, Italy, Spain, Germany, France, Norway and Netherlands.