THERMAL STABILITY OF THE OXIDATION PRODUCTS OF VACUUM GAS OIL

An approach including preliminary oxidation of vacuum gas oil, chromatographic separation of oxidation products, and thermal treatment is considered. Analysis of the products formed in the cracking of polar and non-polar components of vacuum gas oil oxidised with a mixture of hydrogen peroxide and formic acid is described. It has been established that heat treatment of non-polar components allows obtaining up to 85 wt% distillate fractions boiling up to 360 °C, with sulphur content less than 0.3 wt%. The heat treatment of polar components leads to the formation of distillate fractions at a level of about 50 wt%, and sulphur removal reaches 50 %. It has been shown that the cracking temperature of polar oxidation products determines the route of sulphur removal: at a temperature of 450 °C, sulphur-containing fragments are accumulated in coke, while at 500 °C they are predominantly subjected to destruction with the formation of gas components. It has been determined that gaseous products formed in the heat treatment of both polar and non-polar components of oxidised vacuum gas oil mainly consist of saturated hydrocarbons of the C1-C3 series and carbon dioxide. The advantage of separate cracking of polar and non-polar components is elimination of undesired effect on the products formed in thermal decomposition of these components on the route of reactions proceeding in the system. The products obtained in this way are characterized by higher quality. In addition, variation of cracking conditions for separate components of oxidized vacuum gas oil makes it possible to regulate the depth of components destruction and, accordingly, the material balance of the process as a whole.