Hydrogen sulfide (H2S) conversion to hydrogen (H2) and value-added chemicals: Progress, challenges and outlook

Hydrogen sulfide (H2S) is a toxic gas released from natural occurrences (such as volcanoes, hot springs, municipal waste decomposition) and human economic activities treatment biogas production). Even at very low concentrations, H2S can cause adverse health impacts fatality. As such, the containment proper management of paramount importance. The recovered then be transformed into hydrogen (H2) various value-added products major step towards sustainability circular economy. In this review, state-of-the-art technologies for conversion utilization are reviewed discussed. Claus process an industrially established matured technology used in converting to sulfur sulfuric acid. However, energy intensive emits CO2 SO2. This calls more sustainable energy-efficient technologies. particular, recent via thermal, biological, plasma (thermal non-thermal), electrochemical photocatalytic routes, critically with respect their strengths limitations. Besides, potential diversified derived H2S, such H2, syngas, carbon disulfide (CS2), ammonium sulphate ((NH4)2SO4), thiosulfate ((NH4)2S2O3), methyl mercaptan (CH3SH) ethylene (C2H4) elucidated detail readiness level, market demand products, technical requirements environmental impacts. Lastly, technological gaps way forward each also outlined.