Hydrogen can be produced using a variety of technologies and feedstocks, each with different carbon intensities and costs. The main H₂ production methods include:
Electrolysis: Uses electricity to split water into hydrogen and oxygen. When powered by renewable energy, it produces green hydrogen.
Autothermal Reforming (ATR): Converts natural gas into hydrogen using oxygen and steam in a single step; often paired with carbon capture to reduce emissions.
Steam Methane Reforming (SMR): The most common method, using steam to extract hydrogen from methane (natural gas). It emits CO₂ unless paired with carbon capture (blue hydrogen).
Gasification: Converts coal or biomass into hydrogen and other gases through high-temperature reactions.
Methane Pyrolysis: Produces hydrogen and solid carbon from methane without CO₂ emissions, if powered by clean energy.