Despite its image as a clean technology, blue hydrogen produced from gas, even with carbon capture, is significantly worse for the climate than burning coal or gas directly, according to a new study by Cornell and Stanford researchers.
In their peer-reviewed paper, Cornell’s Robert Howarth and Stanford’s Mark Jacobson examined the total ‘lifecycle’ greenhouse gas emissions from blue hydrogen, RenewEconomy reported.
“We see no way that blue hydrogen can be considered ‘green’,” the researchers concluded.
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Emissions associated with producing hydrogen from gas were actually greater than emissions from burning gas or coal directly because of the significant extra energy required for processes to produce hydrogen and power carbon capture and storage, the paper said.
The hydrogen industry is a significant source of climate pollution globally, responsible for around 830 million tonnes of carbon dioxide every year. This is due to the large majority of hydrogen production coming from fossil fuels—being classed as either ‘grey’ (from gas) or ‘brown’ (from coal).
‘Blue’ hydrogen involves producing hydrogen from coal or gas with the addition of carbon capture and storage. ‘Green’ hydrogen is produced using a process called electrolysis powered by renewable energy.
Howarth said while blue hydrogen is often promoted as a climate solution, “unfortunately emissions remain very large”. In Australia, it is largely promoted as clean technology solution by both the gas industry and the federal government.
Energy minister Angus Taylor recently expanded the remit of ARENA to fund blue hydrogen projects, calling it a “next generation low emissions technology”. However, Howarth and Jacobson’s paper says there is no data to support claims that blue hydrogen comes with a low emissions price tag.
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Even when compared to grey hydrogen without carbon capture storage, blue hydrogen’s emissions benefit was small, with cuts ranging between 9 and 12 per cent.
Green hydrogen—that produced using renewable electricity sources—is touted as a key means of reducing future emissions across the globe.
“The best hydrogen, the green hydrogen derived from electrolysis—if used wisely and efficiently—can be that path to a sustainable future,” Howarth stated.
