In the latest print issue, freelance reporter James Dineen explores the 21st-century natural hydrogen gold rush. Geological hydrogen has recently attracted significant interest because it could offer a lower-carbon source of energy. Here is a closer look at its potential, current discoveries and the key questions that remain.
Today, most hydrogen is produced from fossil fuels, especially natural gas. The majority is used in oil refining, fertilizer manufacturing and chemical production. However, as countries work to reduce greenhouse gas emissions, interest is growing in cleaner hydrogen production methods.
A few years ago, the clean hydrogen race appeared likely to focus on two main technologies: electrolyzers powered by renewable energy and fossil fuel-based production combined with carbon capture. Both approaches, however, have faced challenges in achieving widespread adoption, largely because of their high costs.
More recently, the emerging field of geological hydrogen has gained momentum. Companies are exploring naturally occurring hydrogen deposits across Africa, Asia, Europe, Australia and North America, raising the possibility of extracting hydrogen directly from underground formations.
The United States Geological Survey has published a map of natural hydrogen prospects across the country, highlighting areas where the gas is most likely to occur. One promising region is the Midwest, particularly the Midcontinent Rift, which extends from Kansas to Michigan. About a billion years ago, the Earth’s crust stretched and fractured in this region, allowing lava to rise through the cracks. This geological history created large deposits of iron-rich rocks that can react with water to generate hydrogen.
Australian company HyTerra is searching for natural hydrogen in Nebraska and Kansas and has reported gas samples containing concentrations of up to 96% hydrogen. With more than $400 million in total funding, Koloma is among the best-capitalized companies in the natural hydrogen sector and is also conducting operations in the region.
One of the biggest questions facing the natural hydrogen industry is how much hydrogen is generated through geological processes and whether it can be captured efficiently and economically. Hydrogen is an extremely light gas with a small molecular structure, allowing it to move through tiny fractures and pores in underground rocks.
There are encouraging signs. As James reported, researchers examined dozens of boreholes at a mine in northern Ontario and found that each one released approximately eight kilograms of hydrogen annually. With more than 14,000 boreholes at the site, the area could potentially produce a significant quantity of naturally occurring hydrogen.
Source: www.technologyreview.com