Scientists Create Clean Hydrogen While Trapping CO2 in Rocks

Scientists just found a way to tackle two of our biggest climate challenges with one elegant solution buried deep beneath our feet.

Researchers at the University of Texas at Austin have shown that pumping carbon dioxide into certain types of volcanic rock doesn't just lock away the greenhouse gas. It actually helps generate clean hydrogen in the process, creating a win-win for the planet.

The team tested this approach using iron-rich volcanic rocks in conditions that mirror what happens thousands of feet underground. When they added CO2-rich water to the rocks at high pressure and temperature, something remarkable happened: the rocks released more hydrogen than with regular water alone.

Here's why that matters. We desperately need clean hydrogen to replace fossil fuels in industries like steel-making and fertilizer production, which can't easily run on solar or wind power. But nearly all hydrogen today comes from fossil fuels, pumping out massive amounts of CO2.

"We hope to demonstrate that we will be able to generate hydrogen economically while sequestering CO2," says team member Orsolya Gelencsér. The process might even generate geothermal energy at the same time.

The science behind it is surprisingly simple. When water meets these volcanic rocks underground, they naturally produce hydrogen through a process called serpentinization. Adding CO2 speeds things up because it creates carbonic acid, which helps dissolve the rock and allows more water to react with it.

Meanwhile, the CO2 doesn't escape back into the atmosphere. Instead, it gets locked away permanently as solid carbonates in the rock, using technology already proven by a company called Carbfix in Iceland.

The researchers managed to extract about 0.5 percent of the theoretically possible hydrogen from the rocks. They're aiming for 1 percent to make the process economically viable, which they believe is achievable by drilling deeper where temperatures are higher.

The Ripple Effect

The global implications are enormous. These iron-rich volcanic rocks exist in huge volumes around the world, potentially yielding far more than the 100 million tonnes of hydrogen currently produced annually.

Other research teams and startups are now exploring similar approaches. Barbara Sherwood Lollar at the University of Toronto calls it "good work" and notes growing interest in combining hydrogen production with CO2 storage.

The financial picture looks promising too. If companies can charge to lock away CO2 while also selling the hydrogen produced, the dual revenue streams could attract investors and accelerate development.

Field trials with industry partners are the next step. The team wants to prove this can work outside the lab at real-world scale and cost.

We're watching a solution emerge that could clean up heavy industry while pulling carbon from the air, all using rocks that have been waiting underground for millions of years to help us.