×

Hydrocracking of heavy hydrocarbon oils with conversion facilitated by recycle of both heavy gas oil and pitch

  • US 6,004,453 A
  • Filed: 03/06/1998
  • Issued: 12/21/1999
  • Est. Priority Date: 12/21/1995
  • Status: Expired due to Term
First Claim
Patent Images

1. A process for hydrocracking a heavy hydrocarbon oil feedstock, a substantial portion of which boils above 524°

  • C. which comprises;

    (a) preparing a slurry feed of a mixture of heavy hydrocarbon oil feedstock and from about 0.01-4.0% by weight (based on fresh feedstock) of coke-inhibiting additive particles selected from the group consisting of coal, non-coal, fly ash, pyrite and iron compounds which are not active hydrogenation catalysts, passing said slurry feed upwardly through a confined vertical hydrocracking zone in the presence of hydrogen and in the absence of an active hydrogenation catalyst, said hydrocracking zone being maintained at a temperature above about 450°

    C., a pressure of at least 3.5 MPa and a space velocity of up to 4 volumes of hydrocarbon oil per hour per volume of hydrocracking zone capacity,(b) removing from the top of said hydrocracking zone a mixed effluent containing a gaseous phase comprising hydrogen and vaporous hydrocarbons and a liquid phase comprising heavy hydrocarbons,(c) passing said mixed effluent into a hot separator vessel,(d) withdrawing from the top of the separator a gaseous stream comprising hydrogen and vaporous hydrocarbons,(e) withdrawing from the bottom of the separator a liquid stream comprising liquid hydrocarbons and particles of the coke-inhibiting additive,(f) fractionating the separated liquid stream to obtain a pitch bottom stream which boils above 495°

    C., said pitch stream containing said additive particles, and an aromatic heavy gas oil fraction boiling in the range of 360 to 524°

    C.,(g) recycling at least part of said pitch stream containing additive particles to form about 5 to 15% by weight of the feedstock to the hydrocracking zone, and(h) recycling at least part of said aromatic heavy gas oil fraction to form about 15 to 50% by weight of the feedstock to the hydrocracking zone.

View all claims
  • 2 Assignments
Timeline View
Assignment View
    ×
    ×