The most abundant element in the universe, hydrogen, is commonly thought to exist primarily alongside other elements: with oxygen in water, for example, and with carbon in methane. But natural underground pockets of pure hydrogen are punching holes in that notion and generating attention as a potentially limitless 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 laboratories, universities and private companies to develop technologies that could lead to cheap, clean fuel from the subsoil.
Geological hydrogen, as it is known, is produced when water reacts with iron-rich rocks, causing the iron to rust. One of the grant recipients, MIT Assistant Professor Iwnetim Abate's research group, will use its $1.3 million grant to determine the ideal conditions for producing hydrogen underground, considering factors such as catalysts to start the reaction. chemistry, temperature, pressure and pH levels. The goal is to improve efficiency for large-scale production, meeting global energy needs at a competitive cost.
The United States Geological Survey estimates that there are potentially billions of tons of geologic hydrogen buried in the Earth's crust. Stockpiles have been discovered around the world and a host of new companies are looking for removable deposits. Abate seeks to boost the natural hydrogen production process, implementing “proactive” approaches that involve stimulating production and collecting the gas.
“Our goal is to optimize the reaction parameters to accelerate the reaction and produce hydrogen in an economically viable 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 transition to renewable energy, including next-generation batteries and novel chemical methods for energy storage.
Generating innovation
Interest in geological hydrogen is growing at a time when governments around the world seek carbon-free energy alternatives to oil and gas. In December, French President Emmanuel Macron said his government provide financing to explore natural hydrogen. And in February, the government and the private sector witnessed informed US legislators on opportunities to extract hydrogen from the ground.
Today, commercial hydrogen is made for $2 a kilogram, primarily for the production of fertilizers and chemicals and steel, but most methods involve burning fossil fuels, which release Earth-warming carbon. “green hydrogen”, produced with renewable energy, is promising, but at $7 per kilogram, it is expensive.
“If you get hydrogen at a dollar a kilo, it's competitive with natural gas in terms of energy price,” says Douglas Wicks, program director at the Advanced Research Projects Agency – Energy (ARPA-E), the Department of Energy organization that leads the geologic hydrogen grant program.
Recipients of the ARPA-E Grants These include the Colorado School of Mines, Texas tech University and Los Alamos National Laboratory, as well as private companies such as Koloma, a hydrogen production startup that has received funding from amazon and Bill Gates. The projects themselves are diverse and range from the application of industrial oil and gas methods for the production and extraction of hydrogen to the development of models to understand the formation of hydrogen in rocks. The purpose: address questions in what Wicks calls a “total white space.”
“In the case of geological hydrogen, we don't know how we can speed up its production, because it's a chemical reaction, nor do we really understand how to engineer the subsurface so we can extract it safely,” Wicks says. “We're trying to bring in the best skills from each of the different groups to work on this under the idea that the ensemble should be able to give us good answers in a fairly quick period of time.”
Geochemist Viacheslav 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 (to take advantage of the natural reaction between water and rock) present “tremendous potential.”
“The idea is to find ways to speed up that reaction and control it so we can produce hydrogen on demand in specific locations,” says Zgonnik, CEO and founder of Natural Hydrogen Energy, a Denver-based startup that has mineral leases for exploratory drilling. . in the U.S. “If we can achieve that goal, it means we can potentially replace fossil fuels with stimulated hydrogen.”
“A moment of closing the circle”
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, maybe four days a week. Flickering candles or pollutant-emitting kerosene lamps were often the only source of light for homework at night.
“And at home, we had to use firewood and charcoal for tasks like cooking,” Abate says. “That was my story until the end of high school and before I came to the United States to go to college.”
In 1987, diggers were drilling wells for water in Mali, West Africa. discovered a natural hydrogen deposit, causing an explosion. Decades later, Malian businessman Aliou Diallo and his Canadian oil and gas company exploited the well and used an engine to burn hydrogen and generate electricity in the nearby village.
Diallo exited oil and gas and launched Hydroma, the world's first hydrogen exploration company. The company is drilling wells near the original site that have yielded high concentrations of gas.
“So what was once known as an energy-poor continent is now generating hope for the future of the world,” Abate says. “Learning about that was a full circle moment for me. Of course, the problem is global; the solution is global. But then the connection to my personal journey, plus the solution that comes from my home continent, connects me personally to the problem and the solution.”
Experiments that scale
Abate and researchers in his lab are formulating a recipe for a fluid that will induce the chemical reaction that triggers hydrogen production in rocks. The main ingredient is water, and the team is testing “simple” materials for catalysts that will speed up the reaction and, in turn, increase the amount of hydrogen produced, says postdoc Yifan Gao.
“Some catalysts are very expensive and difficult to produce, requiring complex production or preparation,” says Gao. “A catalyst that is cheap and abundant will allow us to improve the production rate; that way, we will produce it at an economically viable rate, but also at an economically viable yield.”
The 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 compositions and geological environments, Abate and Gao are developing what they call a high-throughput system, consisting of artificial intelligence software and robotics, to test different catalyst mixtures and simulate what would happen if They will apply to rocks from various regions, with different external conditions such as temperature and pressure.
“And from there we measure how much hydrogen we are producing for each possible combination,” says Abate. “The ai will then learn from the experiments and suggest to us, 'Based on what I've learned and the literature, I suggest you try this composition of catalyst material for this rock.'”
The team is writing a paper about their project and aims to publish their findings in the coming months.
The next milestone of the project, after developing the catalyst recipe, is to design a reactor that will have two purposes. Firstly, equipped with technologies such as Raman spectroscopy, it will allow researchers to identify and optimize the chemical conditions that lead to better hydrogen production rates and yields. The lab-scale device will also inform the design of a real-world reactor that can accelerate hydrogen production in the field.
“That would be a plant-scale reactor that would be implanted underground,” says Abate.
The interdisciplinary project also leverages the expertise of Yang Shao-Horn, from MIT's Department of Mechanical Engineering and DMSE, for computational analysis of the catalyst, and Esteban Gazel, a scientist from Cornell University who will provide his expertise in geology and geochemistry. . It will focus on understanding iron-rich ultramafic rock formations in the United States and the world and how they react with water.
For Wicks at ARPA-E, the questions Abate and the other grant recipients are asking are just the critical first steps into uncharted energy territory.
“If we can understand how to stimulate these rocks to generate hydrogen, raising it safely, it will really unlock the potential source of energy,” he says. So the emerging industry will look to oil and gas for drilling, pipeline and gas extraction know-how. “As I like to say, this is an enabling technology that we hope, in the very short term, will allow us to say, 'Is there really something there?'”
