China has made a technological breakthrough in the production of hydrogen from seawater by harnessing electricity from renewable marine resources.

CenerTech,a subsidiary of China National Offshore Oil Corporation(CNOOC),on Friday announced that a megawatt-class seawater electrolysis plant pilot facility has completed its trial run,delivering hydrogen with a purity level of 99.999 percent.

The facility has a rated output of 200 standard cubic meters of hydrogen per hour and integrates core operations such as current processing,seawater electrolysis and hydrogen purification in five containers,forming a compact and portable structure suitable for offshore platforms,said the company.

It has been engineered to accommodate the inherent variability and intermittency of offshore wind and solar power,providing an effective solution for the on-site utilization of renewable energy resources,according to the company.

Seawater is a plentiful resource for hydrogen production.Seawater electrolysis allows unstable green electricity to be converted into green hydrogen,which is easier to store and transport.Yet the composition complexity of seawater poses challenges such as catalyst degradation and intense side reactions.

CenerTech's new equipment has enabled direct seawater electrolysis without desalination,thereby cutting costs and ensuring stable,long-term hydrogen production.

"Looking ahead,direct seawater electrolysis will be combined with renewable energy technologies in such areas as offshore wind power to enable the on-site consumption of electricity from remote sea areas,"said Li Zhichuan,a wind power engineer at CenerTech.

This engineering achievement followed the completion of a factory-scale research project to produce hydrogen from seawater earlier this week.The project was undertaken by Sinopec,another state-owned oil refiner,which reported an hourly output of 20 cubic meters of green hydrogen.

（Picture: Veer）