“Grey” hydrogen is obtained from natural gas reforming, which releases 9 kg CO2 per kg of H2 produced:
CH4 + 2H2O → 4H2 + CO2
“Green” hydrogen from water electrolysis uses renewable electricity: 2H2O → 2H2 + O2
Green hydrogen from renewable electricity is 3 to 4 times more expensive than grey hydrogen. These higher costs are mainly atributted to the higher enthalpy associated with water electrolysis (approx. 237 kJ/mol) than methane decomposition (approx. 75 kJ/mol).
Hydrogen storage and distribution infrastructures are scarce, and they will require massive capital investments.
Through methane decomposition, natural gas is decomposed into hydrogen and solid carbon without CO2 emissions:
CH4 → 2H2 + C (s)
When using biomethane or synthetic methane, hydrogen will be produced with a negative carbon balance.
Production costs of zero emissions hydrogen from methane decomposition are very similar to those of grey hydrogen from steam reforming of natural gas.
Methane decomposition can benefit from the already existent infrastructures for storage and distribution of natural gas, which can then be locally converted into Bright hydrogen for decentralized electricity and heat production.
A new catalytic reactor that produces COx-free hydrogen from methane in a cost-competitive process. This reactor operates at low temperatures (500 – 650 ºC), using cyclic regeneration that allows efficient carbon removal for further storage and commercialization.
Pixel Voltaic is currently participating in a consortium for a European project, the 112CO2 Project, proposing socially acceptable, sustainable and easy-to-implement technology to rapidly decarbonise the energy sector at competitive prices.