Modelling of the cyclic chemisorption-catalytic process for production of elemental sulfur and hydrogen from hydrogen sulfide

Abstract

The research is devoted to simulation of cyclic chemisorption-catalytic process for H2S decomposition on the base of bulk FeS catalyst-chemisorbent. The performed simulation of the process has confirmed the possibility to create the stable cyclic non-stationary operation mode with a technologically acceptable duration of chemisorption/regeneration cycles (10-15 minutes and more). Though the maximum calculated per pass conversion of H2S was not higher than 30%, it is possible to achieve practically complete decomposition of H2S to hydrogen and sulfur by recirculation of unreacted H2S. The process may be performed at rather moderate temperatures (not higher 600-650°), it makes possible to use the conventional construction materials for process equipment with reasonable capital costs. The preliminary evaluation has demonstrated that the proposed process, being compared to conventional Claus process, will be characterized with better economic parameters due to the manufacturing of hydrogen which will have ∼5 times higher cost than that of produced sulfur. From the other side, the process may potentially provide the self-cost of the produced hydrogen quite competitive to that of conventional technologies such as conversion of hydrocarbons or water electrolysis. The technology may be applied at oil refineries and natural gas processing plants.