CHARACTERISTICS OF OXIDATIVE DESULFURIZATION OF VACUUM GAS OIL

Abstract

The relevance of the research is caused by the need to develop the methods that are cheaper than hydrodesulfurization for refining vacuum gas oil. The main aim is to establish concentrating relations of oxidation of VGO sulfur-containing constituents. Object of the research is Novokuibyshevsk oil refinery vacuum gas oil. Methods: oxidation, liquid-adsorption chromatography, thin-layer chromatography, X-ray fluorescence determination of sulfur content, material analysis. Results. The authors have determined the optimal conditions for oxidative desulfurization of vacuum gas oil sulfur compounds: duration 90 min, So:Н2О2 molar ration 1:5, stirring speed 2500 rpm. The greatest efficiency of adsorption purification from oxidation products of sulfurorganic compounds is achieved at a mass ratio of «silica gel: object of study»=1:1. The influence of oxidant amount and process duration on the yield of oxidative desulfurization products and the sulfur content in them is shown. The authors determined the oxidation basic patterns of sulfur-containing compounds of oils of vacuum gas oil: increasing of oxidation duration and the molar ratio So:H2O2 does not affect the content of saturated compounds; the yields of mono- and bi-aromatic compounds, the sulfur content in them decreases linearly. With an oxidation time of 30 minutes with increasing molar ratio So:H2O2, the yield and sulfur content of tri and polyaromatic compounds increases due to the accumulation of unadsorbed oxidation products of mono- and bi-aromatic sulfur-containing compounds. The increase in the process duration leads to the development of oxidation side reactions of mono- and biaromatic hydrocarbons, the oxidation products of which are segregated in the composition of polyaromatic hydrocarbons. The oxidized sulfur-containing compounds under these conditions are segregated in the resin composition. Changing of asphaltenes content is insufficient.

Keywords

• Vacuum gasoil
• oxidative desulfurization
• hydrogen peroxide
• sulfur compounds
• resins
• oils