Wildcatting for hydrogen?

The proverbial white and gold rush has already begun as investor-backed startups explore subsurface deposits and develop methods to trigger chemical reactions to boost hydrogen production.

Some are injecting microbes and nutrients into reservoirs to produce hydrogen. Others are exploring use of shale-related techniques such as hydraulic fracturing and water or CO2 injection for hydrogen recovery. Researchers are also evaluating physical stimulation techniques. Many are seeking iron-rich source rock, which reacts with water to create hydrogen as a byproduct via a process called serpentinization.

The search for geologic hydrogen is unfolding as energy demand rises and efforts to reduce emissions continue. Hydrogen produces water when combusted, making it a clean source of energy that can be used to decarbonize hard-to-abate sectors and generate electricity in fuel cells, among other uses. However, finding commercial quantities of natural hydrogen are limited, so initiatives are underway to stimulate its production and economically scale it to commercial levels.

“We’re potentially looking at something clean, something that can potentially be stimulated or can be produced with a minor effort compared to … with  CCUS technologies or electrolysis,” said Marina Domingues, vice president and head of U.S. New Energies, for Rystad Energy.

Geologic hydrogen has also drawn interest from mining companies and E&Ps possibly looking to diversify, and recent headlines in the U.S. are drawing attention, she said.

Houston-based Gold H2, for example, said in June it had produced hydrogen during a field trial at an oil field in California’s San Joaquin Basin, using microbes as part of a process that transforms residual oil. As the company gears up for commercial deployment, it is targeting production costs below 50 cents per kg of hydrogen. Geologic hydrogen’s cost compared to other forms of hydrogen—less than the $2 per kg of hydrogen for gray hydrogen and more than three times that for electrolytic hydrogen by Rystad’s estimates—is also among its advantages.

Exploring to scale

However, there are challenges to overcome to scale hydrogen, panelists said during a session on the topic at the Hydrogen Technology North America Expo in Houston. Besides regulatory hurdles, the sector hasn’t yet found its equivalent of George Mitchell, the pioneer of shale, panelists agreed when asked by session moderator Danny Reible, an engineer chair, researcher and professor at Texas Tech University.

“Clearly, we don’t have one yet. There’s a lot of people that are very excited about stimulated geologic hydrogen and the investment community particularly, mostly venture investors, are also pretty excited about it,” said Colin McCulley, vice president of Vema Hydrogen. “But I think everybody’s got slightly different opinions on how it’ll work. I don’t think it’s going to be what works in Shale 5.0, or whatever the number they’re on, is going to be what’s directly applied to this rock.”

He added a deep technology knowledge of how hydraulic fracture stimulation works is present; however, how that will look for geologic hydrogen remains to be seen. Hopefully, people will get an opportunity to try it out in the field, he said, adding “George Mitchell lost a lot of money before he got it.”

Like natural gas, geologic hydrogen can be tapped by drilling wells into reservoirs and pumping it back to the surface where it is purified before use.

Vema Hydrogen aims to drill its first wells by year’s end, McCulley said. Targeting ophiolites and banded iron formations, the company’s methodology involves use of catalysts to stimulate chemical reactions to produce hydrogen at scale.

“The problem with serpentinization and how hydrogen gets naturally created is the temperature and the conditions required for it,” McCulley said. “You have to get to 350-plus degrees Celsius. Your depths are generally too deep to become commercial. And the issues with that are, they might get solved, but you have to figure out a way to produce this at a much lower temperature.”

The company has experimented in the lab with different rocks, looking for ways to increase the reaction rate at a lower temperature. He didn’t divulge details.

“We need to access a big enough rock volume with a certain amount of surface area so that we can generate hydrogen,” McCulley said. “So, there’s a lot of inputs that go into that,” including well designs and catalysts. “There’s a lot of tools that are commercially available if you want it to change how much surface area you touch. It’s just a matter of cost. But to really enable that, you’ve got to have a catalyst that allows the temperature to be reduced where you can have much higher rates. … We have a catalytic stimulation that occurs at very, very low temperatures.”

Research efforts

As Vema gears up to move from the lab to the field, research efforts that have brought together universities, government agencies and others continue.

The National Renewable Energy Lab has been studying geologic hydrogen, examining the effectiveness of different methods and looking at ways to commercially scale production. Dayo Akindipe, a research scientist for subsurface energy systems at NREL, spoke about the formation of a consortium similar to the Utah Frontier Observatory for Research in Geothermal Energy (FORGE). The field laboratory sponsored by the U.S. Department of Energy has facilitated the development in testing enhanced geothermal system technology. Minnesota, which has been identified as a site for potential significant amounts of geologic hydrogen, would be the gathering site.

“We can actually create a FORGE in Minnesota. … The goal is to drill a demo well and see how we can stimulate that well and bring in a lot of tech people,” Akindipe said. “People can use that as a test bed to test different technologies, different catalysts, different physical mechanical stimulation technologies, proppants, things like that, because we have to keep the fractures open. … And then of course the microbial experiments that we’re doing mostly to first of all to understand how microbes interact with hydrogen.”

Creating a public-facing techno-economic analysis tool is also among the goals, he said.

Investors have already shown they are willing to invest. Backers include BP, Fortescue and mining giant Rio Tinto. Exploratory efforts are underway worldwide.

Given forecasts for load growths with data centers and electrification, energy experts say all forms of energy will be needed.

“We are at a time [when] there is a very high willingness to pay. So, they are investing and looking at different … solutions and different ways to arrange power and to get access to power,” Domingues said of investors. “So, they do hunt for research projects. They’re willing to go down on the technology level rather than just keep investing in more traditional energy such as natural gas.”

For the first time in a while there is a sense of urgency to develop energy resources as energy demand rises.

“The timeline doesn’t look very enthusiastic from a research perspective,” Domingues said, “but from an investment side and from what companies are willing to invest, the risk they’re willing to take is much higher than what we were seeing two or three years ago.”

The U.S. Geological Survey in January released its first map identifying potential areas across the U.S. with geologic hydrogen deposits. Two USGS researchers estimated the Earth may hold 6.2 trillion tons of hydrogen, according to media reports.

Comments