Kinetics of hydrogen sulfide decomposition in a DBD plasma reactor operated at high temperature

摘要

The present study investigates the kinetics of hydrogen sulfide(H_2S) decomposition into hydrogen and sulfur carried out in a nonthermal plasma dielectric barrier discharge(NTP-DBD) reactor operated at～430 K for in situ removal of sulfur condensed inside the reactor walls. The dissociation of H_2S was primarily initiated by the excitation of carrier gas(Ar) through electron collisions which appeared to be the rate determining step.The experiments were carried out with initial concentration of H_2S varied between 5 and 25 vol%at 150 mL/min(at standard temperature and pressure) flow rate in the input power range of 0.5 to 2 W.The reaction rate model based on continuous stirred tank reactor(CSTR) model failed to explain the global kinetics of H_2S decomposition,probably due to the multiple complex reactions involved in H_2S decomposition,whereas Michaelis-Menten model was satisfactory.Typical results indicated that the reaction order approached zero with increasing inlet concentration.