Hydrogen sulfide is a fairly attractive feedstock for hydrogen production. The dissociation energy of H2S (21 kJ/mol at room temperature) is significantly lower than that of water (286 kJ/mol) or even hydrocarbons (76 kJ/mol for methane); moreover, the binding energy of hydrogen in the H2S molecule has the lowest value of all natural hydrogen compounds. However, hydrogen sulfide has not yet found widespread industrial use as a feedstock for hydrogen production. The main obstacle to the development of an effective technology for this purpose is the extremely strict thermodynamic limitations of hydrogen sulfide decomposition into elements: H2S ⇔ S + H2 – Q. This review is focused on analyzing known approaches to producing hydrogen and sulfur from hydrogen sulfide, their shortcomings responsible for the failure of technologies proposed earlier, and approaches to developing effective processes for this purpose. The review places special emphasis on unsteady-state cyclic processes, which can be thought of as one of the most promising routes to develop an efficient technology for H2S decomposition.
Zagoruiko et al. (Sun,) studied this question.