Characteristics of the Hydrocracked Products and Asphaltene with Conversion in a Vacuum Residue Hydrocracking with MoS2 Dispersed Catalyst

As one of the promising technologies for upgrading heavy oils, slurry phase hydrocracking with dispersed catalysts has increased interest in recent times. However, the formation of sediments and coke at a higher conversion is still known as a problem. This study is to find the characteristics of the hydrocracked products and asphaltene with a change of conversion during the hydrocracking of vacuum residue with molybdenum precursor. The experiment was carried out with a variation of reaction temperature from 385 to 440 ‘C, reaction time from 0.5 to 4.0 hours and catalyst concentration from 500 to 10,000 wt.ppm in a 250 cc batch reactor at an initial hydrogen pressure of 80 bar.

As results, API of liquid product increases but the liquid yield decreases with increasing conversion due to the higher formation of gas and coke. Compared to the reaction at a lower temperature with longer time, the one at a higher temperature with short time showed a slightly better liquid yield, API improvement and MCR removal keeping the low hydrogen consumption but the sulfur and metal removals are inferior relatively at the same conversion. When the concentration of catalyst increases, the improvement of conversion was prominent at the low temperature. API increment and desulfurization was higher than that at low concentration of catalysts. Asphaltene in the liquid phase was analyzed in terms of colloidal stability so that it was shown to be worse with increasing the conversion. Based on the ratio of iC4 to nC4 in the gas products, the characteristics between thermal and catalytic cracking was compared with the change of conversion.