No abstract

Heavy crude oil hydrocracking was carried out in a continuous reactor using a liquid acid catalyst. Experiments were conducted at 100 kg/cm2 pressure, a low to moderate reaction temperature (350 and 370 °C), and a hydrogen/hydrocarbon ratio of 10 m3/barrel for 180 h. The reaction temperature was below typical industrial hydrocracking reactors to avoid coke or sediment formation. Experimental results demonstrated that heavy oil was importantly upgraded, hydrocracked oil was less viscous, lighter, and with a higher content of valuable distillates than the original heavy crude oil. Kinetics of the process based on a five lump reaction scheme was determined using a modified Marquard–Levenberg optimization technique. The experimental and calculated yield comparison for each of the lumps is in close agreement.

To evaluate the effect of decanted oil (DO) from fluid catalytic cracking (FCC) units on product sediments in the ebullated bed hydrocracking process (EBHP), an experimental investigation was carried out, in which the reduction of sediments was evaluated by injecting DO into different points of the EBHP. This study was carried out in a H-Oil pilot plant, in which the operation of the industrial EBHP was simulated. To evaluate the effect on the reaction system, DO was injected into the feedstock drum, and to evaluate the effect on the product recovery section, DO was injected into different points of this section. The amount of oil injected was 5 and 10 vol % based on the fresh feed. Experimental results indicate that, when DO is injected together with the feedstock, its effect on sediment reduction is marginal. However, when DO was injected into the product recovery section, sediments were reduced up to 40%. The effect on the reaction system was marginal because the aromatic hydrocarbons of the DO, which should help to maintain asphaltenes in solution, were saturated in the reactors. The effect on the product recovery section may be explained by the asphaltene solubility on the aromatic hydrocarbons of the DO, which contributed to maintain asphaltenes in solution.

No abstract

Heavy crude oil was upgraded into a lighter oil by means of hydrocracking on an acidic Mo–Ni liquid catalyst. Upgrading was measured in terms of specific gravity, viscosity, and distillates yield. The experimental results show that heavy crude oil was upgraded to an extent that depends on the severity of the reaction conditions; in all cases the hydrocracked oil was lighter, less viscous, and richer in valuable distillates (up to 60 wt % more) and contained less contaminants (sulfur and nitrogen) than the heavy crude oil. Hydrocracking experiments were carried out in a batch reactor that was operated at typical hydrocracking conditions, and the conversion was varied by modifying the reaction time over a range from 30 to 90 min or the reaction temperature from 350 to 450 °C. The formation of sediments and toluene-insoluble hydrocarbons increased as the reaction severity and conversion were higher; however, the values obtained were small and lower than those obtained with a commercial heterogeneous catalyst, and in both cases no precipitation was observed. Comparison versus an industrial heterogeneous catalyst under the same reaction conditions indicates that the performance of the liquid catalyst was better in terms of heavy molecules cracking but not as good in terms of contaminant removal.