Turquoise hydrogen is hydrogen produced through the thermal splitting of natural gas in a process called methane pyrolysis. Pyrolysis is the breakdown of fossil fuels such as natural gas, biomass, and waste materials under a high temperature and without the presence of oxygen into useful products like chemicals, biofuels, and carbon black.
To produce turquoise hydrogen, methane (CH4) is heated and converted in a high-temperature reactor into hydrogen (2H2) and solid carbon (C) at temperatures greater than 1000oC powered by an external heat source. The resulting hydrogen gas (2H2) is then separated and used for several applications such as fuel for transportation and industrial processes while the solid carbon black can be easily stored and used as feedstock for chemical synthesis.
Compared to the old methods of producing hydrogen from fossil fuels, methane pyrolysis can be environmentally friendly with little, or no carbon emitted if the external heat energy used to drive the process is derived from renewable electricity, low carbon hydrogen, or biomethane through indirect heating of fuel burners, indirect electrical heating, or direct heating with an electrical plasma. For carbon-neutral turquoise hydrogen production, renewable energy resources such as solar, wind, hydro, or nuclear are required.
Though the production of turquoise hydrogen through methane pyrolysis has more advantages in terms of global net-zero carbon target, large-scale hydrogen economy, and additional income from the already existing carbon black market, it is still an emerging technology that requires more innovative research and investment to reduce the amount of external heat required and to become a commercially viable solution to produce low-carbon hydrogen.