SK E&S, an energy unit of South Korean conglomerate SK Group, said Monday it would invest 33 billion won ($25 million) in a clean hydrogen and materials company in US.

Headquartered in Nebraska, Monolith Materials is currently the only company to have successfully commercialized turquoise hydrogen, according to SK. Turquoise hydrogen is a new addition in the hydrogen color charts that emits zero carbon dioxide during its production.

Through the investment, SK aims to manage the production of diverse kinds of eco-friendly hydrogen, from blue, green to now, turquoise.

By combining Monolith Material’s technology to process turquoise hydrogen with SK E&S’ hydrogen-specific business tactics, SK E&S is planning to seek business opportunities in the domestic market, the company said.

“We will focus on optimizing our portfolio of hydrogen business by making sure we make use of our business skills,” said Kwon Hyung-kyun, vice president of SK E&S’ hydrogen business development.