Hydrocracking process to maximize diesel with improved aromatic saturation
AssigneeChevron U.S.A. Inc.
InventorsDennis R. Cash, Arthur J. Dahlberg
Life of this patent
Estimating the term…
Abstract
A VGO stream is initially hydrocracked in a hydrocracking reaction zone within an integrated hydroconversion process. Effluent from the hydrocracking reaction zone is combined with a light aromatic-containing feed stream, and the blended stream hydrotreated in a hydrotreating reaction zone. Heat exchange occurs between the hydrocracking reaction zone and the hydrotreating reaction zone, permitting the temperature control of the initial hydrocracking zone. The integrated reaction system provides a single hydrogen supply and recirculation system for use in two reaction processes.
Claims16
An integrated hydroconversion process having at least two stages, each stage possessing at least one reaction zone, comprising:
- (a) combining a first refinery stream with a first hydrogen-rich gaseous stream to form a first feedstock;
- (b) passing the first feedstock to a reaction zone of the first stage, which is maintained at conditions sufficient to effect a boiling range conversion, to form a first reaction zone effluent comprising normally liquid phase components and normally gaseous phase components;
- (c) passing the first reaction zone effluent of step (b) to a heat exchanger or series of exchangers, where it exchanges heat with a second refinery stream;
- (d) combining the first reaction zone effluent of step (b) with the second refinery stream of step (c) to form a second feedstock;
- (e) passing the second feedstock of step (d) to a reaction zone of the second stage, which is maintained at conditions sufficient for converting at least a portion of the aromatics present in the second refinery stream, to form a second reaction zone effluent;
- (f) separating the second reaction zone effluent of step (e) into a liquid stream comprising products and a second hydrogen-rich gaseous stream;
- (g) recycling at least a portion of the second hydrogen-rich gaseous stream of step (f) to a reaction zone of the first stage;
- and
- (h) passing the liquid stream comprising products of step (f) to a fractionation column, wherein product streams comprise gas or naphtha stream removed overhead, one or more middle distillate streams, and a bottoms stream suitable for further processing.
An integrated hydroconversion process having at least two stages, each stage possessing at least one reaction zone, comprising:
- (a) combining a first refinery stream with a first hydrogen-rich gaseous stream to form a first feedstock;
- (b) passing the first feedstock to a reaction zone of the first stage, which is maintained at conditions sufficient to effect a boiling range conversion, to form a first reaction zone effluent comprising normally liquid phase components and normally gaseous phase components;
- (c) passing the first reaction zone effluent of step (b) to a heat exchanger or series of exchangers, where it exchanges heat with other refinery streams;
- (d) passing the effluent of step (c) to a hot high pressure separator, where it is separated into a liquid stream which is passed to fractionation, and a gaseous stream, which is combined with a second refinery stream which comprises light cycle oil, light gas oil, atmospheric gas oil or mixtures of all three;
- (e) passing the combined gaseous stream of step (d) to a reaction zone of the second stage, which is maintained at conditions sufficient for converting at least a portion of the aromatics present in the second refinery stream, to form a second reaction zone effluent;
- (f) separating the second reaction zone effluent of step (e) into a liquid stream comprising products and a second hydrogen-rich gaseous stream;
- (g) recycling at least a portion of the second hydrogen-rich gaseous stream of step (f) to a reaction zone of the first stage;
- and
- (h) passing the liquid stream comprising products of step (f) to a fractionation column, wherein product streams comprise a gas or naphtha stream removed overhead, one or more middle distillate streams, and a bottoms stream suitable for further processing.
Dependencies are inferred from the claim text.