Catalytic oxidative decomposition of H2S for hydrogen production

A supported metal sulphide - based catalyst was prepared and studied for the reaction of H2S oxidative decomposition to produce simultaneously H2and sulphur. The study was carried out by investigating different operating conditions such as H2S inlet concentration (10 - 40 vol%), O2/H2S feeding molar ratio (0.2 - 0.35) and reaction temperature (700 - 1,100 °C) with the aim to minimize SO2selectivity and maximize the H2yield together with a good H2S conversion. From the preliminary experimental tests, it was possible to identify the optimal operating conditions (T = 1,100 °C, H2S = 10 vol%, O2/H2S = 0.2), suitable to obtain a high H2S conversion (59 %), a good H2yield (20 %) and depressing the SO2selectivity (< 0.05 %). The catalyst showed a good activity and stability during 10 h of time on stream without any deactivation phenomena. The presence of the catalyst resulted in an improvement of both H2S decomposition reaction to produce H2and partial oxidation reaction to sulphur, realizing simultaneously the abatement of SO2by the Claus reaction.