SK Inc. Materials, an advanced materials unit under South Korea’s SK Group, said Tuesday it is making an additional investment into 8 Rivers, a US clean energy tech firm specialized in developing carbon capture, utilization and storage (CCUS).

With the planned investment, the Korean firm is expected to become the largest shareholder of 8 Rivers. Under the renewed partnership, the two firms are set to further strengthen their existing ties on diverse clean energy products within the US.

Founded in 2008, the North Carolina-based 8 Rivers owns a patent technology that produces clean electricity and blue hydrogen by capturing carbon dioxide. It also has the technology to produce blue hydrogen by liquefying carbon dioxide without needing a separate facility for hydrogen generation.

The enhanced partnership comes the SK company purchased a 12 percent stake in 8 Rivers for $100 million in March last year.

The company said it plans to support 8 Rivers’ ongoing efforts to commercialize clean energy technologies in the US first, where the CCUS business has a favorable environment in terms of regulation and infrastructure. They also plan to expand into other markets.

Earlier the two companies had pledged to seek business expansion in Southeast Asia, another burgeoning market for clean energy tech.

“With the planned funding, we’re expected to make a bigger leap forward by combining both 8 Rivers’ proprietary technologies and our business capabilities,” SK Inc. Materials CEO Lee Young-wook said. “We’ll expand global cooperation and put in our utmost efforts towards global net zero.”

Recently, SK has been strengthening its clean energy business, in addition to its advanced materials business related to semiconductors, displays and batteries.

Last month, it entered the blue ammonia market in partnership with global energy giant ExxonMobil. The two sides made an agreement on the mass production of blue ammonia using next-generation carbon capture technology and the fuel’s adoption in Korea.

Earlier this month, the advanced materials unit also made an equity investment in Ion Clean Energy, a leading US carbon capture technology developer, for a strategic partnership on the development of CCUS technology in Asia.