Patent ID: 8309041

Claim:
A system for use in hydrocracking a heavy oil feedstock and that employs a colloidally or molecularly dispersed catalyst, the system comprising: mixing means for blending a catalyst precursor with a heavy oil feedstock, which includes a significant fraction of hydrocarbons having a boiling point above 343° C. and/or asphaltenes, at a temperature below a decomposition temperature of the catalyst precursor to form a conditioned feedstock composition; heating means for heating the conditioned feedstock composition to above the decomposition temperature to form a colloidally or molecularly dispersed catalyst in situ within the heavy oil feedstock; a first gas-liquid two or more phase hydrocracking reactor configured to received the conditioned feedstock before or after being heated to above the decomposition temperature, the first hydrocracking reactor comprising hydrogen (H 2 ) gas, at least one of the heavy oil feedstock or reaction products of the heavy oil feedstock, and colloidally or molecularly dispersed catalyst at a first concentration that, together with the hydrogen gas, facilitate beneficial upgrading reactions within the heavy oil feedstock; a pressure differential interstage separator configured to receive an effluent from the first hydrocracking reactor and separate the effluent into a lower boiling volatile gaseous vapor fraction and a higher boiling liquid fraction in a manner so that the colloidally or molecularly dispersed catalyst remains in the higher boiling liquid fraction and has increased concentration compared to a concentration of the colloidally or molecularly dispersed catalyst within the first hydrocracking reactor, a valve positioned between the first gas-liquid two or more phase hydrocracking reactor and the pressure differential interstage separator that is configured to induce a pressure drop in a range of about 100 psi to about 1000 psi; and a second gas-liquid two or more phase hydrocracking reactor configured to receive at least a portion of the higher boiling liquid fraction from the pressure differential interstage separator and additional hydrogen (H 2 ) gas, the second hydrocracking reactor containing a second concentration of colloidally or molecularly dispersed catalyst greater than the first concentration within the first hydrocracking reactor, wherein the second increased concentration of colloidally or molecularly dispersed catalyst within the second hydrocracking reactor provides increased conversion and/or reaction rate and/or throughput.