Austrian company Voestalpine produces the world's first hydrogen-based rail, setting new standards in steel production

Hydrogen-based steel production uses—ideally green—hydrogen from renewable energy sources to separate oxygen from iron ore. Unlike conventional methods, this process does not generate CO2, only water vapor as a byproduct. The hydrogen-reduced pure iron was produced in the HYFOR pilot plant, and the melt was carried out in the company’s proprietary research facility Technikum Metallurgie (TechMet), a one-of-a-kind miniature full-scale steelwork.

Addition:

You maybe interested in the Green Steel Tracker: It show which low-carbon projects have been announced in the steel industry, and aims to support decision makers in policy and industry, academia as well as civil society, by tracking public announcements of low-carbon investments in the steel industry and presenting them transparently in one place.

Regarding the number of project for green steel that are already announced, South Korea's Posco, Luxembourg-based Arcelor Mittal, India's Tata, Germany's Thyssen Krupp, and Sweden's SSAB are leading the way among the large steel conglomerates.

There is also a good overview for the global green cement market by market research group Precedence Research. It list 8 keyplayers: Mexico's CEMEX S.A.B., Japan's Taiheiyo Cement Corporation, the two Chinese companies Anhui Conch Cement and China National Building Material, Brazil's Votorantim cimentos S.A., the two Indian companies UltraTech Cement Ltd. and ACC Limited., Switzerland's LafargeHolcim, Germany's Heidelberg Cement AG, and the Taiwan Cement Corporation.

But the researchers list a lot of very good projects from companies around the globe.