Patent ID: 7935243
Filing Date: 2011-05-03
Classification: C10G

Abstract:
1. A process for hydroprocessing a heavy oil feedstock, the process employing a plurality of contacting zones and separation zones, the process comprising: combining a heavy oil feedstock, a hydrogen containing gas, and a slurry catalyst in a first contacting zone under hydrocracking conditions to convert at least a portion of the heavy oil feedstock to lower boiling hydrocarbons, forming upgraded products; sending a mixture of the upgraded products, slurry catalyst, hydrogen containing gas, and unconverted heavy oil feedstock to a first separation zone, whereby the upgraded products are removed with the hydrogen containing gas from the first separation zone as a first overhead stream, and the slurry catalyst, heavier hydrocracked liquid products and the unconverted heavy oil feedstock are removed from the first separation zone as a first non-volatile stream, and; sending the first non-volatile stream to a contacting zone other than the first contacting zone, which contacting zone is maintained under hydrocracking conditions with additional hydrogen containing gas to convert at least a portion of the unconverted heavy oil feedstock to lower boiling hydrocarbons, forming additional upgraded products; sending a mixture comprising the additional upgraded products, slurry catalyst, additional hydrogen containing gas, and unconverted heavy oil feedstock to a separation zone other than the first separation zone, whereby the additional upgraded products are removed with the additional hydrogen containing gas as an overhead stream and the slurry catalyst and the unconverted heavy oil feedstock are removed as a second non-volatile stream; wherein the contacting zones are maintained under hydrocracking conditions at a temperature of 410° C. to 600° C., and a pressure from 10 MPa to 25 MPa, and the first contacting zone is operated at a temperature of at least 10° F. lower than a next contacting zone, wherein water is added to the first contacting zone in an amount of 1 to 25 weight % on the weight of the heavy oil feedstock.