Deactivation of fiber-supported La0.65Sr0.35Ni0.29Co0.69Fe0.02O3 catalyst by mercaptan during combustion of methane or natural gas Original Research Article

A fiber-supported La0.65Sr0.35Ni0.29Co0.69Fe0.02O3 perovskite combustion catalyst has been developed. The preparation technique consisted of in-situ perovskite formation via incipient fiber blanket wetting, followed by freeze-drying. The catalyst activity, per gram of perovskite, is higher than that of unsupported fine La0.65Sr0.35Ni0.29Co0.69Fe0.02O3 powder. Kinetics of deactivation of this catalyst by sulfur oxides, resulting from total oxidation of methyl-mercaptan during methane and natural gas combustion, has been studied in a CSTR Berty reactor. The effects of temperature, methane contact time and mercaptan concentration, as well as combustion products were evaluated. The experimental data has been fitted by a simple deactivation model based on Levenspielʹs formalism. The observed deactivation rates were relatively slow in comparison to known deactivation rates by sulfur dioxide of some transition metal based catalysts. In particular, the catalyst seems to tolerate mercaptan concentration levels, commonly used to odorize commercial natural gas, as confirmed by long term tests in an integral reactor.