HIGHLY ACTIVE CATALYSTS FOR OXIDATION OF THIOLS

Abstract

The problem of disposal of toxic and corrosion-active sulfhydryl substances (deodorization), natural hydrocarbons is relevant to operational and environmental aspects. One method of removing these impurities is catalytic oxidation to non-toxic disulfide form. The message shows the results of a comparative study of the oxidation reaction of thiols by oxygen to disulfides in hydrocarbon media, catalyzed by complexes of copper salts (I, II) with various nitrogen-containing bases. As nitrogen-containing ligands, mono - and diethanolamine with different C4-C18 hydrocarbon radicals were used. It is established that water-soluble catalyst composition on the basis of monoethanolamine and the hydrocarbon-soluble complex of copper Cu(II) with N-octadecyldiethanolamine exhibits low activity in the oxidation of 1-octanethiol. It was found the activating effect of HCl on the activity of catalysts in various hydrocarbons (model mixture, vacuum gasoil, naphtha and gas condensate of the Karachaganak field), which allows for an exhaustive oxidation of thiols with the initial concentrations ≥1000 ppm. However, the introduction of hydrogen chloride is accompanied by the appearance of corrosion. The introduction of corrosion inhibitors have led to the complete deactivation of the catalysts. The high-performance catalytic system based on CuCl2/CuO was designed, for which we found the optimum ratio of catalyst/inhibitor, to eliminate the corrosion effect while maintaining a high level of activity. The kinetics of the oxidation reaction of the sulfhydryl derivatives by oxygen was studied. It was found that regardless of the nature of the hydrocarbon media, for all investigated catalysts a zero order on concentration of the thiol and close to first order on the catalyst concentration is observed. The use of developed catalysts and purification technology in the industry will reduce the environmental hazard during the transportation and storage of petroleum products.Forcitation:Pletneva I.V., Gavrilov Yu.A. Highly active catalysts for oxidation of thiols. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 8. P. 70-73.