Blue hydrogen is possibly bad for the climate change
The use of blue hydrogen has been seen as a viable and eco- environmentally energy alternative. But through a study released on Thursday said it could lead to higher greenhouse gas emissions than coal through its production.
Hydrogen is often viewed as an important energy carrier in a future decarbonized world. Most hydrogen is produced by steam reforming of methane in natural gas (“gray hydrogen”), with high carbon dioxide emissions.
Increasingly, many propose using carbon capture and storage to reduce these emissions, producing so-called “blue hydrogen,” frequently promoted as low emissions.
Currently, hydrogen is used mostly by industry during oil refining and synthetic nitrogen fertilizer production, and little is used for energy because it is expensive relative to fossil fuels.
Often, blue hydrogen is described as having zero or low greenhouse gas emissions. However, this is not true as not all carbon dioxide emissions can be captured, and some carbon dioxide is emitted during the production of blue hydrogen.
The vast majority of hydrogen (96%) is generated from fossil fuels, particularly from steam methane reforming (SMR) of natural gas but also from coal gasification. But methane is known to be a powerful greenhouse gas.
And about 25% of the net global warming that has occurred in recent decades is estimated to be due to methane gas.
The researchers have lambasted “blue hydrogen,” saying it “appears difficult to justify on climate grounds.”
“Blue hydrogen is hardly emissions-free,” according to an article in the academic journal Energy Science and Engineering.
But the researchers warned that using the fuel, which involves carbon capture and storage (CCS), as part of a clean energy 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.”
And a 2019 IEA report touted hydrogen’s potential “to become a critical part of a more sustainable and secure energy future.”
But the production is energy-intensive, with emissions released during the heating and pressuring process and from the use of natural gas as a base fuel to generate hydrogen, according to the study by Cornell’s Robert Howarth and Stanford’s Mark Jacobson.
While blue hydrogen does contain some of the emissions, the paper notes that energy also is needed in the carbon-capture process.
As a result, it “provides no benefit,” since the combined emissions of carbon dioxide and methane, another greenhouse gas, are greater for blue and gray hydrogen than for natural gas, diesel oil, or coal.
“We suggest that blue hydrogen is best viewed as a distraction, something that may delay needed action to truly decarbonize the global energy economy,” the authors said.