Directly engineered green hydrogen production by water splitting reaction powered by geothermal source: A thermodynamic and mechanistic breakthrough

Green hydrogen is considered as future fuel due to its clean, efficient and green production pathway. Water electrolysis is a key pathway for green hydrogen production, which utilises electricity to split water into hydrogen and oxygen with zero carbon emissions when powered by renewables. Geothermal driven green hydrogen production represents one of the best alternative for green energy transitions in terms of economic, environmental, thermodynamic and industrial point of view. The present study highlights a novel integration of geothermal power based green hydrogen production using alkaline electrolyser which substantially reduces capital investment, offers industrial grade scalability and longer lifespan with minimum environmental impacts. The source of green hydrogen is geothermal water, which splits by electro-catalytic reaction mechanism producing hydrogen at the rate of 2500 mL/min. The transition metal based double layered electrode system favoured HER kinetics which is obviously supported by SEM, BET, and CV analysis. The produced hydrogen is directed through a compressed pipeline to a specially designed storage cylinder (Type II) that can efficiently store compressed hydrogen at high pressure. The purity of produced hydrogen is 99.999 %. The reduced energy barrier of 205.2 kJ/mol for water splitting reaction strongly favours enhanced HER kinetics. The cycle wise continuous operation of the plant validated the technology at industrial grade statistics in terms of production and storage efficiency. The techno-economic costing suggests a significant benefit cost of production of $ 1.5098 which evaluates rapid marketing prospects of the technology. On a lifetime scale production, reduced LCOH of $1.54/kg-H2 demonstrates a high order system for industrial grade application. The overall system efficiency of 82.1 ± 5.47% suggest a highly efficient geothermal power based hydrogen production which significantly reduces electrical power consumption, enhances hydrogen production rate with minimum uncertainty losses.