Why turquoise hydrogen will Be a game changer for the energy transition.

With hydrogen being promoted as a promising energy vector for a decarbonized world, low-carbon hydrogen production methods are of interest to replace the current Steam-Methane-Reforming production of "grey" hydrogen. While existing studies focus on the life-cycle-assessment of green hydrogen produced by water electrolysis, an alternative, which has attracted growing interest due to a much lower energy intensity (10–30 kWh/kgH2 < 50–60 kWh/kgH2), is turquoise hydrogen produced by the pyrolysis of methane. Specifically, this study conducts a life-cycle-assessment on hydrogen produced by the pyrolysis of methane via thermal-plasma. A sensitivity analysis is also conducted on the environmental-metric time-horizon and on the methane emissions rates. Results show that the carbon-intensity of hydrogen produced using this novel method is 88.3–90.8% lower than that of grey hydrogen. Furthermore, using renewable-natural-gas with a feedstock percentage as low as 8–18% leads to a negative hydrogen carbon-intensity (reaching −4.09 to −10.40 kgCO2e/kgH2 at 100% renewable natural gas), the lowest compared to grey, blue, and green hydrogen, making turquoise hydrogen a game-changer for the energy transition. [Display omitted] • Hydrogen produced by methane pyrolysis via thermal plasma has a very low carbon intensity of 0.91 kgCO2e/kg. • Sourcing of natural gas is the main factor impacting the carbon intensity. • Improving natural gas sourcing up to grade A (MiQ) reduces the carbon intensity of hydrogen to 0.45 kgCO2e/kg. • Replacing the natural gas feedstock with renewable natural gas gives a negative carbon intensity of hydrogen of -4.09 to -10.40 kgCO2e/kg. • Turquoise hydrogen performs better environmentally than grey and blue hydrogen, and using RNG, performs better than green hydrogen. [ABSTRACT FROM AUTHOR]