Hydrogen is often viewed as the fuel of the future. Scientists initally predicted it will be clean, renewable and efficient. Making it work, though, might be a problem. Some of the current technologies, including a process known as “blue” hydrogen, can pollute more than traditional fossil fuels.
Blue hydrogen is derived from methane in natural gas. It has previously been touted as a better alternative because the production emissions are captured and stored deep underground. However, new research indicates that this energy alternative could actually be worse than burning coal.
A peer-reviewed study published in Energy Science & Engineering, an open-source journal, concludes "the greenhouse gas footprint of blue hydrogen is more than 20 percent greater than burning natural gas or coal for heat and some 60 percent greater than burning diesel oil for heat," according to the paper.
In addition, carbon dioxide is a byproduct of blue hydrogen production. While the plan is to capture and store the gas, the question remains as to what to do with that supply in the future. There is also concern about the long-term viability of holding it underground, reports Loz Blain of New Atlas.
Climate scientists Robert Howarth and Mark Jacobson, authors of the new study, point out this storage process is likely not as “clean” as previously thought. The Cornell and Stanford researchers, respectively, report that considerable amounts of methane escape into the atmosphere as natural gas is extracted from the Earth. Based on industry standards, they estimate the leakage rate at 3.5 percent of consumption for these “fugitive emissions,” or unintentionally leaked gases.
In just 20 years, one ton of methane emissions can warm the air 86 times more than carbon dioxide, reports Tim De Chant of Ars Technica.
“Our analysis assumes that captured carbon dioxide can be stored indefinitely, an optimistic and unproven assumption,” the study authors write in the paper. “Even if true though, the use of blue hydrogen appears difficult to justify on climate grounds.”
Oil and gas companies are hoping to switch to hydrogen in the near future. However, producing hydrogen is expensive and will likely remain so for the next few decades.
The $1 trillion infrastructure package that was just approved in the United States Senate aims to make hydrogen a more accessible resource. The bill includes $8 billion to develop four regional “clean hydrogen” hubs to provide a low-emission source of fuel for transportation and home heating, reports Oliver Millman of the Guardian.
As a stop-gap measure, energy producers propose using “gray” hydrogen processes, which are less costly but produce more methane and carbon dioxide. This process involves exposing natural gas to high heat, pressure and steam, which releases greenhouse gases into the atmosphere, reports Ars Technica.
“Combined emissions of carbon dioxide and methane are greater for gray hydrogen and for blue hydrogen (whether or not exhaust flue gases are treated for carbon capture) than for any of the fossil fuels,” the study authors write in the paper. “Methane emissions are a major contributor to this, and methane emissions from both gray and blue hydrogen are larger than for any of the fossil fuels.”