ITHACA, N.Y. — Blue hydrogen, an energy source involving a process for the creation of hydrogen via methane in natural gas, is supposed to be a “green” asset in the fight against climate change. Unfortunately, researchers from Cornell University and Stanford University reports this supposed clean energy source may be worse for our planet than burning fossil fuels.
According to their study, the carbon footprint incurred by creating blue hydrogen is 20 percent higher than using either natural gas or coal directly for heat and roughly 60 percent greater than using diesel oil for heating purposes.
To create blue hydrogen, scientists convert methane to hydrogen and carbon dioxide via heat, steam, pressure – just like creating gray hydrogen. However, the blue hydrogen process takes things a step further by collecting some additional carbon dioxide as well. After getting rid of that byproduct carbon dioxide and any other impurities, the remains become blue hydrogen. That’s all well and good, but study authors say that creating blue hydrogen requires tons of energy, usually attained by burning more natural gas.
“In the past, no effort was made to capture the carbon dioxide byproduct of gray hydrogen, and the greenhouse gas emissions have been huge,” says study co-author Robert Howarth, professor of ecology and environmental biology at Cornell, in a university release. “Now the industry promotes blue hydrogen as a solution, an approach that still uses the methane from natural gas, while attempting to capture the byproduct carbon dioxide. Unfortunately, emissions remain very large.”
Still producing harmful emissions
Methane is a particularly powerful methane gas which scientists believe is 100 times stronger as an atmospheric warming agent than carbon dioxide. According to the The United Nations’ Intergovernmental Panel on Climate Change released earlier this month, methane has contributed about two-thirds as much to global warming as carbon dioxide cumulatively over the past century.
It is true that emissions for blue hydrogen are lower than gray hydrogen, but only by roughly nine to 12 percent.
“Blue hydrogen is hardly emissions free,” the study reads. “Blue hydrogen as a strategy only works to the extent it is possible to store carbon dioxide long-term indefinitely into the future without leakage back to the atmosphere.”
On Aug. 10, the U.S. Senate passed the $1 trillion Infrastructure Investment and Jobs Act. That legislature includes an allocation of several billion dollars toward developing and building the hydrogen technology industry.
“Political forces may not have caught up with the science yet,” Howarth says. “Even progressive politicians may not understand for what they’re voting. Blue hydrogen sounds good, sounds modern and sounds like a path to our energy future. It is not.”
A greener alternative
There is a third option however — green hydrogen. This variety of hydrogen is by far the most clean, researchers explain, although it remains a very small sector with little commercial activity today. Green hydrogen is the result of water experiencing electrolysis. The water eventually has its hydrogen and oxygen components separated.
“The best hydrogen, the green hydrogen derived from electrolysis – if used wisely and efficiently – can be that path to a sustainable future,” Howarth concludes. “Blue hydrogen is totally different.”
The study is published in the journal Energy Science & Engineering.