A detailed reaction mechanism for hydrogen production via hydrogen sulphide (H2S) thermolysis and oxidation. (4th May 2016)

• Record Type: Journal Article
• Authors: Cong, Tay Yu; Raj, Abhijeet; Chanaphet, Jirawan; Mohammed, Shabin; Ibrahim, Salisu; Al Shoaibi, Ahmed
• Is Part Of: International journal of hydrogen energy. Volume 41:Number 16(2016)
• Page Start: 6662
• Page End: 6675
• Publication Date: 2016-05-04
• Subjects: H2S -- Thermolysis -- Reaction mechanism -- H2 yield -- Synergistic effect; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2016.03.053
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Hydrogen production from the thermolysis of undesirable hydrogen sulphide (H2 S) represents a viable means of extracting energy from it while enhancing the efficiency of Claus process, which is a widely used technology for sulphur recovery from H2 S laden streams of oil and gas industries. This paper examines the thermolysis of H2 S for direct hydrogen and sulphur production. A detailed reaction mechanism is proposed that captures the chemistry involved in its high temperature decomposition. The simulation results obtained using the proposed mechanism is compared with a wide range of experimental data from plug flow and stirred reactors, premixed laminar flames, and shock tubes, and a satisfactory agreement between them is found. Significant improvements in model predictions are obtained with the proposed mechanism when compared to previously published mechanism. After its validation, the mechanism is then used to investigate the major reactions involved in hydrogen production. It is shown through simulations under adiabatic conditions that the addition of small amount of oxygen in the inlet H2 S gas stream exhibits a synergistic effect in H2 yield, and can significantly enhance the production of hydrogen. The results reported herein provide design guidelines and viable means of seeking cost effective methods of hydrogen production from industrial waste streams containing H2 S. Highlights: A reaction mechanism for H2 S thermolysis is developed. Experimental data from a wide variety of reactors and flames are used for mechanism validation. A synergistic effect in H2 yield during H2 S thermolysis is observed when O2 is added to H2 S feed. Reaction path analysis is presented to determine the reactions responsible for H2 and S2 formation from H2 S.