Manufacturing blue hydrogen emits 20 percent more carbon than burning natural gas or coal for heat
Hydrogen – considered a clean source of energy – could lead to higher greenhouse gas emissions than coal, according to a new study by researchers at Cornell and Stanford Universities.
The study examined the greenhouse-gas emissions generated by the production of “blue” hydrogen. The process uses steam heat to turn natural gas into carbon dioxide and hydrogen. The carbon dioxide is captured but the process also generates methane, a potent greenhouse gas.
Researchers Robert Howarth, a biogeochemist and ecosystem scientist at Cornell, and Mark Jacobson, director of Stanford’s Atmosphere/Energy Program, found that manufacturing blue hydrogen emitted 20 percent more carbon than burning natural gas or coal for heat.
“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 wrote.
The peer-reviewed study was published in the Energy Science & Engineering journal. It comes out just months after the U.S. Department of Energy announced $52.5 million in funding for 31 projects to support “next generation clean hydrogen.”
Source: CGTN – 14-Aug-2021 https://newsus.cgtn.com/news/2021-08-14/Study-Blue-Hydrogen-isn-t-green-energy-12I2O4AbZcY/index.html
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Green hydrogen vs blue hydrogen explained
Green hydrogen
Green hydrogen is extracted using a method that does not produce green house gas (GHG) emissions. As the name suggests, its production is sustainable and environmentally friendly. Green hydrogen is most commonly produced using a device called an electrolyser. Electrolysers use electricity to split water into hydrogen and oxygen. The key to this method of producing green hydrogen is that the electricity that powers the electrolyser comes from renewable sources, such as wind, solar,
which have no associated GHG emissions. There
are also pathways to produce green hydrogen from waste biomass.
Blue hydrogen
Blue hydrogen is produced using a process called ‘steam reforming’, which uses steam to separate hydrogen from natural gas. This process does produce GHGs, but carbon capture and storage technologies capture and store those emissions.
Other hydrogen processes
Hydrogen can (and is) also extracted from natural gas using steam reforming but in this case, relevant technologies don’t capture resulting emissions. Instead, they are released into the atmosphere. Similarly, hydrogen can be extracted from brown and black coal via gasification. This is an established process used in many industries that convert carbon-rich materials into hydrogen and carbon dioxide. As a result, gasification releases those GHG by-products into the atmosphere.
Source: CSIROscope, 27 May, 2021 https://blog.csiro.au/green-blue-brown-hydrogen-explained/