Production of hydrogen from hydrogen sulfide assisted by dielectric barrier discharge

Hydrogen production by non-thermal plasma (NTP) assisted direct decomposition of hydrogen sulfide (H2S) was carried out in a dielectric barrier discharge (DBD) reactor with stainless steel inner electrode and copper wire as the outer electrode. The specific advantage of the present process is the direct decomposition of H2S in to H2 and S and the novelty of the present study is the in-situ removal of sulfur that was achieved by operating DBD plasma reactor at ∼430 K. Optimization of various parameters like the gas residence time in the discharge, frequency, initial concentration of H2S and temperature was done to achieve hydrogen production in an economically feasible manner. The typical results indicated that NTP is effective in dissociating H2S into hydrogen and sulfur and it has been observed that by optimizing various parameters, it is possible to achieve H2 production at 300 kJ/mol H2 that corresponds to ∼3.1 eV/H2, which is less than the energy demand during the steam methane reforming (354 kJ/mol H2 or ∼3.7 eV/H2).

► Design of a DBD plasma reactor for H2S direct decomposition into H2 and S. ► Separation of S from the product mixture. ► Optimization of reaction conditions for economical production of hydrogen.