Theoretically, hydrogen could be the fuel of the future. It is the most common element in the universe and its combustion produces no harmful emissions. Most industrial hydrogen comes from a process called steam reforming that extracts it from natural gas – basically methane. Carbon dioxide is a byproduct of the process. But it is also possible to get hydrogen by breaking down water resulting only in oxygen as a byproduct. There is a great deal of ongoing development of so-called green hydrogen.
New research from Princeton University and the National Oceanic and Atmospheric Administration has uncovered a potential problem associated with the use of hydrogen as a clean fuel.
There is a molecule in the atmosphere called the hydroxyl radical. It is known as “the detergent of the troposphere”. It plays a critical role in eliminating greenhouse gases such as methane and ozone from the atmosphere. It turns out that the hydroxyl radical also reacts with any hydrogen gas in the atmosphere and there is only so much hydroxyl to go around. If large amounts of hydrogen were to enter the atmosphere, much of the hydroxyl radical would be used up reacting with it and there would be much less available to break down methane. As a result, there would end up being more methane in the atmosphere, and methane is a powerful greenhouse gas.
The bottom line is that there would need to be proactive efforts to limit the amount of hydrogen getting into the atmosphere whether from producing it, transporting it, or anyplace else in the value chain. Otherwise, the hydrogen economy would cancel out many of the climate benefits of eliminating fossil fuels.
Photo, posted June 12, 2021, courtesy of Clean Air Task Force via Flickr.