SK Inc., the holding company of SK Group, is expediting the expansion of its eco-friendly hydrogen business, a key area of its ESG management. The company announced on June 3 that it has invested in Monolith, a U.S. company that succeeded in mass-production of turquoise hydrogen for the first time in the world.

Participants in Monolith’s funding round, which was completed on June 3, included Nextera, the largest power generation and renewable energy development company in the United States.

Turquoise hydrogen is produced by decomposing natural gas, of which methane (CH4) is the main component, into hydrogen (H2) and solid carbon (C) in a high-temperature reactor.

Based in Nebraska, the United States, Monolith was founded in 2012. The company has developed a reactor that produces high-purity cyanide and solid carbon from natural gas through pyrolysis.