Can seawater make green hydrogen?

Untreated seawater could be an alternative to purified water in electrolysers to create hydrogen, researchers have found

Big Zero Report 2023

Untreated seawater can be split to create green hydrogen.

That’s according to researchers from the University of Adelaide, who claim splitting natural seawater into oxygen and hydrogen can be done with ease and without creating large emissions.

This technique utilises electrolysis and the team say it has the same level of performance of metal-based electrolysers that are commonly used at the moment.

“Current electrolysers are operated with highly purified water electrolyte. Increased demand for hydrogen to partially or totally replace energy generated by fossil fuels will significantly increase scarcity of increasingly limited freshwater resources,” explained Associate Professor Yao Zheng who worked directly on the study.

Finding a way to create the green hydrogen without having to even treat seawater would speed up the process rapidly, as using entirely purified water can take a while, he explains.

Given that seawater is a far more abundant resource, if the research proves successful and scalable, it could change plans around hydrogen production globally.

Zheng added: “Our work provides a solution to directly utilise seawater without pre-treatment systems and alkali addition, which shows similar performance as that of existing metal-based mature pure water electrolyser.”

Seawater was used with a commercial electrolyser to see if it could be taken to market in the future.

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