With scientists rethinking approach, the Front Range is quickly becoming a hub in the search underground for hydrogen.
Scientists, entrepreneurs and federal officials are searching furiously for a carbon-free fuel they hope to find buried underground. The search is fueled by a recent and dramatic change in thinking about hydrogen gas formed deep within the Earth, known as geologic hydrogen, and its potential as a significant clean energy source.
“Geologic hydrogen has massive potential,” said Mengli Zhang, a geophysicist at the Colorado School of Mines. “The geologic hydrogen gold rush is coming.”
The Front Range has emerged as a hub of research and development in this search. In February, Colorado scientists discussed geologic hydrogen with U.S. senators in Washington, D.C., and colleagues at a scientific conference in Denver; a private Denver-based company raised almost $250 million to find economically retrievable hydrogen gas; the federal government awarded the Colorado School of Mines $1.5 million to develop tools to help collect hydrogen gas; and the School of Mines and the Lakewood office of the U.S. Geological Survey announced a consortium of academic, government and private institutions devoted to finding and collecting hydrogen gas.
Hydrogen is the most common, lightest element in the universe. In its pure form, it is a colorless, odorless, nontoxic gas. Pure hydrogen, however, is relatively rare in nature. It is so chemically reactive that it combines avidly with other elements to make water, hydrocarbons and many other compounds. And many microbes feast on it.
Rocket fuel
Hydrogen gas is also a powerful, energy-dense fuel. It is literally rocket fuel; most rockets heading for orbit carry large tanks of hydrogen and oxygen, which combine to produce tremendous energy to thrust the rockets skyward. The only byproduct is water – no greenhouse gases or toxic pollutants.
Hydrogen could provide clean fuel for many uses that are not amenable to solar, wind and hydropower, such as nonpolluting fuel for planes, trains and long-haul trucks, ammonia for fertilizer and high-grade heat for steel and cement production. It can also be used in portable, small-scale fuel cells. If successfully mined and collected, hydrogen could supply energy 24/7, even when the sun doesn’t shine or the wind doesn’t blow.
There are several practical challenges to hydrogen’s widespread use, from storage to distribution and leakage. It is not clear if existing natural gas pipelines can transport hydrogen. Carrying it in train or truck tankers requires high pressures and seriously low temperatures. And when hydrogen gas leaks into the atmosphere, chemical reactions can destroy molecules that remove the powerful greenhouse gas methane, while producing other chemicals that increase greenhouse warming.
Millions of tons of hydrogen are produced each year. However, the processes used are expensive and dirty. They require large amounts of energy and create substantial amounts of carbon dioxide. This process can be made cleaner by fueling the process through renewable solar, wind and hydropower or by sequestering carbon dioxide produced when fossil fuels are used. The U.S. Department of Energy recently committed $7 billion for seven Regional Clean Energy Hubs (none in Colorado), to accelerate the production and distribution of clean hydrogen gas and reduce costs from about $5 per kilogram to $1 per kilogram.
In essence, manufactured hydrogen gas serves as a form of energy storage, not a novel source of energy. The energy originally stored in fossil fuels and renewables is transferred to hydrogen gas as it is produced. And it takes more energy to produce hydrogen gas than is released when it is burned. Hydrogen gas produced within the Earth takes very little energy to collect and use, thus adding new energy to the system.
Geologic processes within the Earth produce hydrogen gas. When water under high temperature and pressure reacts with iron-rich rock, it produces hydrogen gas. This process, called serpentinization, is considered the most widespread and promising for geologic hydrogen retrieval. Other processes deep within Earth’s mantle and core also produce hydrogen.
For millennia, there have been sporadic anecdotes about hydrogen gas seeping from underground. The original Olympic torch is said to have been lit more than 2,500 years ago from a hydrogen-rich flame that still seeps from the ground in Turkey. Some hot springs, including ones at Yellowstone National Park, also bubble with gas rich in hydrogen.
But it has long been geological dogma that there are no significant underground pools of hydrogen. It is such a small molecule, capable of seeping through the tiniest pores and cracks, that geologists believed until recently that it could never collect underground in sizable reservoirs.
“Five years ago, if you had asked me, ‘can you get accumulations of hydrogen?’ I would have said, ‘No, this is something that we know,’” said Geoffrey Ellis, a petroleum geochemist with the USGS Energy Resources Program in Lakewood. “We’ve drilled wells all over the world. We never found it. It’s not out there.”
Chance discovery
Ellis began to reconsider that opinion after learning about a sizable reservoir of hydrogen found in Mali, Africa. The pool had been uncovered in 1987, blowing out of a dry well originally drilled for water. When a worker at the site leaned over the hole with a lit cigarette in his mouth, the wind blowing out of the hole ignited into a roaring flame that terrified local residents. The well was capped, abandoned and ignored for decades until 2012, when Malian entrepreneur Aliou Diallo reexamined it as part of his search for oil and gas. The wind coming from the well turned out to be 98% hydrogen. It was burned in a converted Ford engine hooked to a generator that produced electricity for a nearby town. Coups and political unrest have prevented further investment and development of the field.
This discovery was described in a scientific paper published in 2018, which Ellis came across in 2019. “My first response was, ‘There’s got to be something wrong.’ … It doesn’t make sense,” Ellis said. “So, I set it aside and went back to what I was working on.” The COVID pandemic, however, provided Ellis with 90 extra minutes a day he did not have to spend commuting. So, he gave the paper and other sources a second look.
“I pretty quickly came to the realization that, yeah, we were too quick to dismiss this and no one’s really looked for it. Maybe we should start thinking about it,” Ellis said. “We just haven’t been looking for hydrogen in the right places with the right tools.”
Not long after, Ellis persuaded a panel of USGS geologists, in a process informally known as the Shark Tank, to fund a pilot study of geologic hydrogen. In October 2022, he and his colleague Sarah Gelman produced a very rough estimate of how much hydrogen gas might be lurking underground. The estimate ranged from not enough to make any real difference to enough to power human civilization for thousands of years.
Their findings were promising enough to fund further research about the quantity and potential locations of hydrogen reservoirs. Two regions in the United States have garnered most of the attention. One is the Midcontinent Rift, where spreading of Earth’s crust brought ancient iron-rich rocks near to the surface. It runs from Kansas through Iowa, Minnesota and Michigan. Another potential hot spot is along the Eastern Seaboard.
In February, Ellis told members of the Senate Committee on Energy and Natural Resources that he and his colleagues expect to produce later this year a “prospectivity map,” that further refines promising locations that can guide private companies in their search for hydrogen gas.
Well-funded search is on
Also testifying to the committee was Pete Johnson, CEO and co-founder of Koloma, a Denver-based “data-driven, technology enhanced geologic hydrogen exploration company.” Johnson, entrepreneur and chief business officer Paul Harraka and Ohio State University geochemist Tom Darrah co-founded Koloma in Denver in 2021. Since then, they have been “actively gathering and analyzing data, conducting lab experiments, leasing mineral rights and exploring in prospective regions within the United States,” according to Johnson. They are relying, to a large extent, on Darrah’s research and expertise to guide their efforts. Darrah, and to a lesser extent, Johnson, have applied for numerous patents — eight in 2023 alone — on a variety of methods for finding, producing and storing geologic hydrogen.
In February, Koloma raised $245 million from investors, including from the Amazon Climate Pledge Fund and the United Sustainable Flight Fund. That is on top of $91 million invested in 2023 by Breakthrough Energy, a climate innovation organization started by Bill Gates.
Koloma has drilled a few exploratory wells, said co-founder Harraka. In line with their generally guarded public comments, he declined to say where those wells were drilled or what results came from them.
In contrast, Natural Hydrogen Energy, another Denver-based startup, publicly announced that it had drilled the world’s first well explicitly looking for hydrogen in 2019 in Nebraska. Company founder Viacheslav Zgonnik said the well has produced hydrogen but that it has not yet been captured or used.
Soviet legacy
Zgonnik was one of the earliest believers in the potential of geologic hydrogen, in part because of a now-discredited belief about hydrogen and hydrocarbons held by scientists in the Soviet Union. They believed that hydrogen is an important ingredient in the geologic formation of oil and gas, tested for hydrogen gas in many of their wells and actively looked for it as a marker for oil and gas accumulations. Many of those drilling records faded into obscurity with the fall of the Soviet Union.
Zgonnik spent seven years searching through obscure archives, many of them available only in paper, and compiled a comprehensive list of more than 300 hydrogen seeps across the globe. His paper, published in 2020, provided important evidence for the existence of geologic hydrogen. USGS’s Ellis called it “the authoritative paper on geologic hydrogen right now.”
Zgonnik works out of Paris. (France and Australia are very active in geologic hydrogen research and development.) His company is registered in Denver, although no employees currently reside here. He chose Denver as his U.S. headquarters because one of his team members was based here and it offered access to many skilled oil and gas industry workers. Zgonnik and Johnson cited the potential for people in the oil and gas industry to bring their skills to hydrogen gas exploration and collection.
“Some of the best technology and most talented technical people in our country come from the traditional energy industry,” Johnson told U.S. senators. “This is a great opportunity to leverage that massive talent advantage this country has developed.”
Hydrogen gas as a renewable resource
“But key questions remain,” Johnson told senators. “Are there accumulations that are big enough to matter? Are they close to markets? Can we find them through intentional, economic exploration efforts?” He also mentioned pending tax credits that could dramatically impact investors’ willingness to invest in the future of geologic hydrogen. While Johnson strongly believes in the promise of geologic hydrogen, he acknowledged the possibility of a “bust scenario” that ends with “a really small puff of hydrogen from one well out in a farmer’s field” or a large find in Greenland where it is economically unrecoverable.
Even if no large, economically recoverable pools of hydrogen are found, there could still be a way to tap geologic hydrogen. Earth continually produces hydrogen through ongoing geologic processes, making hydrogen gas a renewable resource.
“For four-and-a-half billion years, Earth has been making hydrogen and will continue to do so,” Alexis Templeton, a geomicrobiologist at the University of Colorado, told scientists in February during the annual conference of the American Academy for the Advancement of Science. The academy publishes the prestigious scientific journal Science, which named geologic hydrogen one of the 2023 Breakthroughs of the Year. Ellis, with the USGS in Lakewood, and Zhang, with the School of Mines, also spoke during the session.
“We are on the frontier right now”
It seems unlikely that there are any places producing enough hydrogen in real time to be useful, but Templeton and others have been exploring another idea: pumping water underground into iron-rich rocks to produce hydrogen gas at much faster rates.
Templeton comes to the geologic hydrogen field from a different angle than most, looking at hydrogen gas as an energy source for the multitudes of microbes living underground. She has been funded in part by NASA, to see if hydrogen produced by other rocky planets might support extraterrestrial life.
She turned her attention to geologic hydrogen on Earth as a potential energy source in 2022 when the U.S. Department of Energy approached her. She now has a grant from the Grantham Foundation for the Protection of the Environment and is working with the private company Eden Geopower to understand the various chemical, thermal and mechanical factors that could best stimulate the production of geologic hydrogen. She hopes to test the concept later this year by drilling a well into iron-rich rock formations in Oman.
The Advanced Research Projects Agency-Energy, or ARPA-E, made the federal government’s first investment in stimulated geologic hydrogen, doling out $20 million for 16 research and development projects, including $1.5 million to the Colorado School of Mines. Zhang and Yaoguo Li will develop tools to monitor real-time production of stimulated hydrogen from wells. They are also adapting tools used for oil and gas exploration to locate hydrogen reservoirs underground.
Researchers at the National Renewable Energy Laboratory are also dipping their toes into the geologic hydrogen search by collaborating with Texas Tech University and other partners on one of the ARPA-E grants and conducting tech-to-market analyses to assess the commercial viability of geologic hydrogen as a novel energy source.
Zhang, Li and Ellis, at USGS, are also leading a consortium that was announced in February of academic institutions and small startups and large energy companies, called Geo H2, to further explore and develop the potential of geologic hydrogen. The consortium will allow the participants to share and combine their skills and assets to further advance the field.
For now, geologic hydrogen is little more than a gleam in the eye of optimistic researchers, entrepreneurs and investors. No one has yet found, tapped and used geologic hydrogen beyond one well that provides electricity for one small town in Africa. No one even knows for sure if such economically retrievable reserves exist.
“We are on the frontier right now,” Templeton said. “Will we do this? Can we do this?”
The answers to those questions may well be found in Colorado.
SOURCE: The Colorado Sun
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