Controlling Sediments in the Ebullated Bed Hydrocracking Process

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.