Patent ID: 7575670
Filing Date: 2009-08-18
Classification: C10G,C10L

Abstract:
1. A process for the production of low sulfur diesel from a low quality feedstock which process comprises: a) reacting a feedstock having at least a portion boiling at greater than 565° C. (1050° F.) and hydrogen in a first hydrodesulfurization reaction zone containing hydrodesulfurization catalyst to produce a first hydrodesulfurization reaction zone effluent stream comprising diesel boiling range hydrocarbons and hydrocarbons having a reduced concentration of sulfur, and hydrogen; b) recovering a liquid hydrocarbonaceous stream having at least a portion boiling at greater than 565° C. (1050° F.) and a reduced concentration of sulfur, a liquid hydrocarbonaceous stream comprising diesel boiling range hydrocarbons and first hydrogen-rich gaseous stream; c) reacting the liquid hydrocarbonaceous stream comprising diesel boiling range hydrocarbons and at least a portion of the first hydrogen-rich gaseous stream in a second hydrodesulfurization reaction zone to produce a second hydrodesulfurization reaction zone effluent, wherein the first hydrodesulfurization reaction zone is operated at a pressure greater than the pressure in the second hydrodesulfurization reaction zone; d) separating the second hydrodesulfurization reaction zone effluent to provide a second hydrogen-rich gaseous stream containing hydrogen sulfide and a stream comprising low sulfur diesel; e) rejecting at least a portion of the hydrogen sulfide from the second hydrogen-rich gaseous stream containing hydrogen sulfide; and f) recycling at least a portion of the second hydrogen rich gaseous stream having a reduced concentration of hydrogen sulfide to the first hydrodesulfurization reaction zone.