Denver-registered Natural Hydrogen Energy hopes to begin the commercial extraction of hydrogen from sites in the American Midwest later this year. It follows the drilling of its first exploratory well in February 2019 and the purchase of mineral leases over what it describes as the most promising geological sites identified during an exhaustive survey process.

“Scientists have long been aware of the presence of hydrogen in the earth’s crust, but it was considered a geological curiosity and too small to be of interest,” says CEO Viacheslav Zgonnik, who launched Natural Hydrogen Energy in 2013 after starting research into hydrogen extraction in 2011 as part of a post-doctoral thesis.

“Scientists and explorationists were not deliberately looking for it, and you cannot find what you are not looking for,” he says. This is especially the case as gas detection equipment is not designed to measure hydrogen concentrations in natural gas samples. “The presence of natural hydrogen has been underestimated and is much more abundant than previously thought.”

“Hydrogen of geologic origin has the potential to become the renewable energy source of the future”

Electrolysis is widely considered to be the most viable method to make green hydrogen and the long-term alternative to fossil fuel-based steam reforming. Hydrogen extraction remains a fringe idea—the websites of the US energy department and industry lobby group Hydrogen Europe, for example, make no mention of it.

But interest in what Zgonnik dubs ‘natural hydrogen’ increased after a well in West Africa proved the concept by producing 98pc pure H₂ from 2012. Today, the well runs a generator that provides sufficient electricity for a nearby village, in what Zgonnik describes as the first commercial exploitation of natural hydrogen.

Viable technology

Zgonnik hopes his company will be at the heart of the next stage of development. “The technology is ready. The next steps will be to purchase the necessary commercial equipment and to drill several more wells [in 2021],” says Zgonnik. “The expenses are in an order of magnitude of normal expenditure for oil and gas drilling. We have a list of potential sites for expansion of the project in the US and elsewhere.”

He prefers to refer to hydrogen extraction, rather than mining, because the gas’s presence in the earth’s crust is effectively infinite, like geothermal energy; unlike a coal mine, or oil or gas field, a hydrogen well will not become exhausted.

“The hydrogen is renewable. It is constantly generated by inorganic geochemical reactions. Because it is a very small molecule, it diffuses to the earth’s surface from the depths of the earth, entering the atmosphere and rising into space. The flow is constant and permanent over time,” says Zgonnik. “This hydrogen is not related to sedimentary or fossil deposits—it comes from deeper layers of the earth’s crust and mantle.”

While the logic for extracting hydrogen is similar to that for capturing geothermal energy, the process will be similar to the production of natural gas. Zgonnik claims hydrogen extraction can become cheaper than making the gas via steam reforming, currently the most inexpensive method.

“You need to do exploration, drilling and extraction, purification and transmission of gas, and build a steam reforming plant to convert it to hydrogen. With natural hydrogen, it is a similar process of exploration and production, but you do not need the reforming part,” he says.

Hydrogen well depths will range from hundreds of metres to several kilometres, depending on the local geology. Academic research suggests wells could produce from hundreds of kilograms to several tonnes of hydrogen daily, according to Zgonnik.

“Our mission is to decarbonise the energy industry. Hydrogen is often seen as a vector of energy, so you need to manufacture it from something else—you need to use electricity or energy stored in other molecules—but with natural hydrogen it is a source of energy and is no longer just a vector,” says Zgonnik.

“You do not need to expend any energy to produce it. All you need is to drill and build a well to extract it. It is a gamechanger for the hydrogen economy in general—because a main criticism of the hydrogen industry is the amount of energy required to manufacture the gas. You do not need to build costly infrastructure like solar or wind farms or electrolysers to obtain green hydrogen.”

Academic support

Zgonnik published an academic review paper in 2020 detailing the myriad instances in which the presence of hydrogen in the earth was noted in scientific studies. “These finds were seen as unique, but when considered together it is clear that hydrogen is present at a global scale,” he says. “Hydrogen of geologic origin has the potential to become the renewable energy source of the future.”

He estimates such sources could provide an annual flow of 23mn t of hydrogen and stresses the hydrogen discovered so far, aside from that by his company, was found by accident and mostly during oil and gas exploration in sedimentary basins. Yet such locations are not rich in hydrogen—other rock formations make for substantially more abundant sources of the gas.

“Natural hydrogen is present on all continents… [it] is sufficiently abundant to replace fossil fuels entirely”

Hydrogen is the lightest gas, diffuses rapidly in air and other substances, combines with oxygen to make water, and is also consumed by microorganisms—all of which make it difficult to detect.

For example, hydrogen-rich gases were only discovered at a site in Russia after 20 years of research at the location. Moreover, hydrogen concentrations vary considerably in small areas and short time periods, while research shows hydrogen concentrations increasing simultaneously at locations 50km apart, “suggesting a global-scale process as being the cause of this synchronous behaviour”, Zgonnik wrote in the paper.

His paper lists 16 hydrogen discoveries in ophiolite regions—where the tectonic forces are believed to have lifted the oceanic crust—in Turkey, the US, Philippines, New Caledonia, Bosnia and Oman. Hydrogen discoveries are also found in wells drilled into Precambrian rock, with some of the highest concentrations topping 80pc. Wells in Siberia were documented to have hydrogen flows of up to 100,000m³/d, according to the paper.

“Natural hydrogen is present on all continents,” adds Zgonnik. “At this scale, natural hydrogen is sufficiently abundant to replace fossil fuels entirely.”

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Author: Matt Smith