Investigation on the catalytic conversion of hydrogen sulfide to methyl mercaptan as a novel method for gas sweetening: Experimental and modeling approaches

• Published in: Journal of natural gas science and engineering 2019-01, Vol.61, p.97-105
• Main Authors: Khaksar, S.A.M., Zivdar, M., Rahimi, R.
• Format: Article
• Language: English
• Subjects: H2S conversion; Mathematical modeling; Methyl mercaptan synthesis; Pilot scale; Sour gas
• ISSN: 1875-5100
• DOI: 10.1016/j.jngse.2018.11.009

The conventional method for gas sweetening is the conversion of hydrogen sulfide to solid sulfur. Although this method has some advantages, researchers are trying to come up with more beneficial technologies. In light of this requirement, a modified experimental method based on the method previously proposed by Yermakova and Mashkina in 2004 is used in the current study. The main idea of this method is modified as the novelty of this investigation which is utilization of mixture of H2S, propane and butane, as a sour gas instead of pure hydrogen sulfide. Modified mathematical approach based on the model previously proposed by Yermakova and Mashkina in 2004 is used to convert the hydrogen sulfide to methyl mercaptane. In this way, in the first stage of this study, experimental investigation is performed to investigate the possible effect of three different parameters of molar ratio, mass flow rate and inlet temperature. After that the obtained results are utilized to mathematically model the proposed sweetening method. The overall results demonstrated that although application of H2S mixtures leads to lower conversion rate of H2S to methyl mercaptane due to lower partial pressure of H2S regarding the presence of impurities of propane and butane, the catalytic conversion of H2S to valuable chemicals can be an applicable and feasible tool for industrial purposes. •A rigorous mathematical model is developed.•Two different cases (pure H2S and sour gas in the feed stream) are verified and compared.•The effect of other hydrocarbons, such as propane and butane, on the reactions kinetic is investigated.•The accuracy of the model is examined by comparing the results with the experimental data, derived from a pilot scale.