Hydrogen is an attractive fuel - in some ways. It can be used directly in making ammonia for fertilizers (a huge global use), as a chemical feedstock in other industries, and in stationary power plants. As a transportation fuel it’s more problematic, being difficult and expensive to store.
Worldwide, we make a lot of hydrogen - about 100 million tons a year, mostly from natural gas, so that’s a source of greenhouse gas emissions. Making it by electrolyzing water with solar or wind power is superior, but it’s a bit difficult to get it in the right places and times.
What if we could mine it? It seemed unlikely, given that most rock strata are oxidized. However, geologist Geoff Ellis with the US Geological Survey surveyed recent findings in the journal Science Advances. Scientists have found vast amounts of free (uncombined) hydrogen gas underground. It forms where iron-rich rocks such as fosterite react with water around them. The first big deposit was found in Mali in 1987, with more coming. Total reserves could fuel our energy demands for 200 years.
Still, other sources of energy are far better. Hydrogen occurs in small deposits. It’s very hard to gather and hard to transport. Natural hydrogen gas is, nonetheless, a fascinating geological phenomenon.
This has been an outreach activity of the Las Cruces Academy, viewable at GreatSchools.org
Source: Physics Today, Feb. 2025, pp. 18-19
Image: Science, 8 Feb. 2024
