Controlling Sediments in the Ebullated Bed Hydrocracking Process

Abstract

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.

Batch Reactor Study of the Effect of Aromatic Diluents to Reduce Sediment Formation during Hydrotreating of Heavy Oil

“…Comparison of results with literature reports. (a) (●) this work, (◇) Ortega García; (b) (□) without diluent, (○) LCO, (△) HCO, and (●) DO.…”

“…14,15 Some studies have reported that using DO as diluent has a positive effect on reduction of sediment formation in both catalytic hydroprocessing and thermal cracking processes. 7,15,16 By examining the properties of the DO used in the literature, it is lighter and with higher content of aromatics as compared with that used in this work, presumably having lower amount of complex molecules like poly aromatics, which may explain its inverse tendency in the formation of sediments. Stratiev et al 16 reported that the addition of similar diluents has a positive effect in reducing the formation of sediment during the H-Oil vacuum residue hydrocracking, Other results reported that the addition of 10 wt % of DO shows more sediment content than those obtained during the VR hydrocracking without diluent, which agrees with the results obtained in this work.…”

“…Ortega Garci ́a et al 7 evaluated the effect of injecting a decanted oil from fluid catalytic cracking unit (FCC) together with a vacuum residue to an ebullated-bed hydrocracking pilot plant. They stated that when decanted oil is added to the feedstock, its effect on sediment formation is marginal because the aromatic hydrocarbons of the diluent were saturated during the reaction.…”

Novel Ebullated Bed Residue Hydrocracking Process

“…Residue hydrocracking has been attracting more and more attention to the refining industry in recent decades, and one of the best approachs is ebullated bed residue hydrocracking (EBRH) . The ebullated bed hydrocracking process has been integrated in some refineries to upgrade heavy hydrocarbons (residues) from petroleum . A homogeneous environment is created to hydrotreat and hydrocrack the problematic heavy feedstocks with a high amount of metals and asphaltenes.…”

“…6 The ebullated bed hydrocracking process has been integrated in some refineries to upgrade heavy hydrocarbons (residues) from petroleum. 7 A homogeneous environment is created to hydrotreat and hydrocrack the problematic heavy feedstocks with a high amount of metals and asphaltenes. Hydrocarbon and hydrogen are fed upflow through a catalyst bed with very flexible operation (high and low conversion modes).…”