It is commonly believed that the most copious element in the universe, hydrogen, occurs mainly with other elements – for example, oxygen in water and carbon in methane. However, naturally occurring underground deposits of neat hydrogen challenge this concept and attract attention as a potentially unlimited source of carbon-free energy.
One interested party is the U.S. Department of Energy, which last month awarded $20 million in research grants to 18 teams from labs, universities and private companies to develop technologies that could extract inexpensive, neat fuel from the earth.
As you know, geological hydrogen is formed when water reacts with iron-rich rocks, causing the oxidation of iron. One of the grant recipients, MIT assistant professor Iwnetima Abate’s research group, will utilize its $1.3 million grant to determine the ideal conditions for underground hydrogen production – taking into account factors such as the catalysts that initiate the chemical reaction, temperature, pressure and pH levels. The goal is to improve the efficiency of large-scale production, meeting global energy demand at competitive costs.
The U.S. Geological Survey estimates that there are potentially billions of tons of geological hydrogen in the Earth’s crust. Accumulations have been discovered all over the world, and many startups are looking for deposits that can be extracted. Abate wants to accelerate the natural hydrogen production process by implementing a “proactive” approach that includes stimulating production and acquiring gas.
“Our goal is to optimize reaction parameters to speed up the reaction and produce hydrogen in an economically feasible way,” says Abate, Chipman Development Professor in the Department of Materials Science and Engineering (DMSE). Abate’s research focuses on the design of materials and technologies for the renewable energy transition, including next-generation batteries and novel chemical energy storage methods.
A spark of innovation
Interest in geological hydrogen is growing at a time when governments around the world are looking for zero-emission energy alternatives to oil and gas. In December, French President Emmanuel Macron announced that his government would do so provide financing to test natural hydrogen. And in February, government and private sector witnesses – informed US lawmakers regarding the possibility of extracting hydrogen from the ground.
Currently, commercial hydrogen is produced for $2 per kilogram, mainly for fertilizers, chemical production and steel, but most methods involve burning fossil fuels, which release Earth-warming carbon. “Green hydrogen”, produced using renewable energy, is promising, but at $7 per kilogram, it is expensive.
“If hydrogen costs a dollar a kilogram, it is competitive with natural gas in terms of energy price,” says Douglas Wicks, program director at the Advanced Research Projects Agency for Energy (ARPA-E), the organization that runs the Department of Energy’s grant program for geological hydrogen.
Recipients of the above-mentioned ARPA-E grants include the Colorado School of Mines, Texas Tech University and Los Alamos National Laboratory, as well as private companies including Koloma, a hydrogen production startup that has received funding from Amazon and Bill Gates. The projects themselves range from applying industrial oil and gas production and extraction methods to producing and extracting hydrogen to developing models to understand the formation of hydrogen in rocks. The goal: to address questions within what Wicks calls “complete white space.”
“With geological hydrogen, we don’t know how to speed up its production because it’s a chemical reaction, nor do we really understand how to engineer the subsurface so that we can extract it safely,” Wicks says. “We try to employ the best skills of each group, guided by the assumption that the team should be able to give us good answers in a fairly short time.”
Geochemist Vyacheslav Zgonnik, one of the leading experts in the field of natural hydrogen, agrees that the list of unknowns is long, as is the path to the first commercial projects. But he says efforts to stimulate hydrogen production – aimed at harnessing the natural reaction between water and rock – have “huge potential”.
“The idea is to find ways to speed up this reaction and control it so that we can produce hydrogen on demand in specific places,” says Zgonnik, CEO and founder of Natural Hydrogen Energy, a Denver-based startup that leases minerals for exploration drilling in United States. “If we can achieve this goal, it means we can potentially replace fossil fuels with stimulated hydrogen.”
“A Full Circle Moment”
For Abate, the connection to the project is personal. When he was a child in his hometown in Ethiopia, power outages were common – the lights went out three or four days a week. Flickering candles or polluting kerosene lamps were often the only source of lightweight when doing homework at night.
“And in the household, we had to use wood and charcoal for things like cooking,” Abate says. “That was my story until the end of high school and before I came to the United States for college.”
In 1987, diggers drilled for water in Mali, West Africa discovered natural hydrogen deposits, causing an explosion. Decades later, Malian entrepreneur Aliou Diallo and his Canadian oil and gas company turned on the well and used the engine to burn hydrogen and generate electricity in a nearby village.
Leaving oil and gas behind, Diallo launched Hydroma, the world’s first hydrogen exploration company. The company drills wells near the original extraction site, where high gas concentrations were detected.
“So what was once known as an energy-poor continent now generates hope for the world’s future,” Abate says. “Finding out about this was a full circle moment for me. Of course, the problem is global; the solution is global. But the connection to my personal journey and the solution coming from my home continent make me personally connected to the problem and the solution.
Experiments on this scale
Abate and researchers in his lab are developing a recipe for a liquid that will trigger a chemical reaction that produces hydrogen in rocks. The main ingredient is water, and the team is testing “simple” materials for catalysts that will speed up the reaction and therefore boost the amount of hydrogen produced, says postdoc Yifan Gao.
“Some catalysts are very expensive and difficult to produce and require complex production or preparation,” Gao says. “An inexpensive and abundant catalyst will allow us to increase our production rate – this way we will produce it at an economically viable rate, but also at an economically feasible yield.”
Iron-rich rocks in which the chemical reaction occurs can be found throughout the United States and the world. To optimize the reaction in a variety of geological compositions and environments, Abate and Gao are developing a so-called high-throughput system, consisting of artificial intelligence and robotics software, to test different mixtures of catalysts and simulate what would happen when applied to rocks from different regions , with different external conditions such as temperature and pressure.
“From this we measure how much hydrogen we produce for each possible combination,” says Abate. “Then the AI will draw conclusions from the experiments and suggest to us: ‘Based on what I have learned and based on the literature, I suggest testing the composition of the catalytic material for this rock.’”
The team is writing a paper on their project and intends to publish the findings in the coming months.
The next milestones of the project, after developing the catalyst recipe, are the design of a reactor that will serve two purposes. First, equipped with technologies such as Raman spectroscopy, it will enable scientists to identify and optimize chemical conditions that lead to improved hydrogen production rates and efficiency. The laboratory-scale device will also be used to design an actual reactor that can accelerate hydrogen production in the field.
“It would be a plant-scale reactor that would be implanted below the surface,” Abate says.
The interdisciplinary project also leveraged the expertise of Yang Shao-Horn from MIT’s Department of Mechanical Engineering and DMSE in the field of catalytic computational analysis, and Esteban Gazel, a scientist from Cornell University, who will share his knowledge in the field of geology and geochemistry. It will focus on understanding iron-rich ultramafic rock formations in the United States and around the world and how they react with water.
For ARPA-E’s Wicks, the questions being asked by Abate and other grantees are just critical first steps into uncharted energy territory.
“If we understand how to excite these rocks to produce hydrogen and extract it safely, we will really unlock a potential energy source,” he says. The emerging industry will then seek expertise in drilling, pipelines and gas production in the oil and gas sector. “As I like to say, this is an enabling technology that will hopefully, in the very short term, allow us to say, ‘Is there really something to this?’”