Researchers in the US have recently come up with a new process that combines carbon dioxide with industrial waste to produce green hydrogen at a projected cost of less than USD 1 per kilogram (USD 0.45 per pound).
The technology was developed by researchers at the Ohio State University. It uses industrial by-products including steel slag and coal ash, to capture carbon dioxide (CO2). The reactions permanently convert the gas into high-purity calcite, which is a mineral widely used in construction, agriculture, and pharmaceuticals.
The chemical reactions involved in capturing the carbon reduce the amount of energy needed to split water through electrolysis and produce green hydrogen. According to the research team, the technology could prevent about 500 million metric tons of carbon dioxide pollution annually.
Tomaz Neves-Garcia, PhD, lead author of the study and postdoctoral researcher at the university, emphasized that CO2 is an abundant resource that should be captured and reused. “Our technology does not treat CO2 as a burden that must be managed,” Neves-Garcia explained.
From waste to clean fuel
Green hydrogen is produced by using electricity to split water into hydrogen and oxygen. It is a promising tool for decarbonizing the planet, as it has no negative impact on the environment.
However, electrolysis requires significant amounts of electricity, which can make green hydrogen expensive. Data shows that unsubsidized green hydrogen costs up to USD 7 per kilogram (3.18 per pound) globally in 2026. To address the issue, the Ohio State team created a method that successfully captures CO2 with steel slag and coal ash.
“Instead of wasting energy, we are actually creating value and creating energy,” Neves-Garcia pointed out. “This is what makes the potential of this process really impactful.”
In the team’s demonstration, the CO2 reacted with the industrial by-products to form high-purity calcite. The reactions simultaneously lowered the energy needed for electrolysis. This enabled the production of hydrogen with negative emissions even when using widely available grid electricity.
Slashing carbon emissions
The approach could also provide steel and coal industries with a way to make use of waste materials that would otherwise have limited value. Robert Baker, PhD, a professor at Ohio State and senior author of the study, said that the method turns two abundant waste streams into valuable products for fuels and manufacturing.
“It also has the potential to make a significant economic impact without relying on carbon credits, government subsidies or environmental mandates,” he noted in a press release.
What’s more, when the value of the calcite produced alongside the hydrogen is included, the team projects production costs of less than USD one per kilogram (about USD 0.45 per pound). That could make the technology competitive with conventional hydrogen produced from fossil fuels.
Baker said that the approach could have an economic impact without depending on carbon credits, government subsidies, or environmental mandates. If deployed widely across interconnected industries, it could prevent about 500 million metric tons (551 million US tons) of CO2 pollution every year.
“Climate solutions do not only not have to be more expensive, they can also be simpler, scalable and economically attractive,” Neves-Garcia concluded. “We have the ability now to implement them.”
The study has been published in the journal ACS Energy Letters.
