brown hydrogen

Brown hydrogen is produced by extracting hydrogen from coal through a process called gasification, which involves heating coal in the presence of oxygen. This method releases hydrogen gas but also generates significant carbon dioxide emissions, contributing to climate change. While hydrogen itself is clean fuel, brown hydrogen's environmental impact is high due to these emissions. It is considered the least sustainable of hydrogen production methods and is often viewed as a transitional step toward cleaner options like green hydrogen, which uses renewable energy to produce hydrogen without emitting CO₂.