Heterogeneous Decomposition of a Hydrogen Sulfide-Methane Sour Mixture Flowing in a Rectangular Channel

Abstract

In this work, we analyze the heterogeneous conversion process of hydrogen sulfide acid, H₂S, to atomic hydrogen, H⁰ , in a binary gas mixture composed by the above acid component and methane gas. We consider that the sour mixture flows in a horizontal rectangular channel under a laminar, hydrodynamically fully-developed flow regime and the decomposition process takes place on the internal walls of the channel made by iron. The heterogeneous chemical activity on the metallic walls is conducted by a reactive scheme based on four reactions: one adsorption, two electrochemical, and an exothermic reaction needed to complete the conversion process. The longitudinal profiles of the species H₂S and H₀ on the surfaces of the channel as functions of the nondimensional parameters involved in the present model, are shown. In addition, the surface coverages of the chemical products HS^– , H⁺ and H⁰ , together with the surface coverage of the vacancies derived from the chemical and electrochemical reactions are presented.