Patent ID: 7601254

Claim:
A process for conversion of a hydrocarbon feedstock to produce olefins, saturated hydrocarbons, aromatic compounds, naphtha hydrocarbons having a boiling range from 36° C. (97° F.) to 193° C. (379° F.), and ultra low sulfur diesel (ULSD) which process comprises: (a) reacting the hydrocarbon feedstock in a fluid catalytic cracking zone to produce a hydrocarbon product mixture comprising C 2 -C 3 olefins, C 4 -C 6 olefins, C 4 -C 6 saturated hydrocarbons, C 7 -C 9 hydrocarbons and light cycle oil (LCO); (b) passing the C 2 -C 3 olefins from step (a) to a light olefin separation zone to produce at least an ethylene-enriched stream and a propylene-enriched stream; (c) reacting the C 4 -C 6 olefins and C 4 -C 6 saturated hydrocarbons from step (a) in an olefin cracking zone to produce olefin cracking zone product mixture comprising C 2 -C 3 olefins, C 4 -C 6 saturated hydrocarbons, and a C 6 + hydrocarbons stream; (d) separating at least a portion of the C 2 -C 3 olefins, C 4 -C 6 saturated hydrocarbons, C 6 + hydrocarbons stream from the olefin cracking zone product mixture of step (c), recovering at least a portion of the C 2 -C 3 olefins and C 4 -C 6 saturated hydrocarbons and passing at least a portion of the C 6 + hydrocarbons stream to step (e); (e) reacting the C 7 -C 9 hydrocarbons from step (a) and at least a portion of the C 6 + hydrocarbons stream from step (d) in a naphtha hydrotreating (HT) zone to produce a naphtha HT zone product mixture comprising aromatic compounds and naphtha hydrocarbons and recovering the naphtha HT zone product mixture; (f) reacting the LCO from step (a) in a two-stage process comprising a 1 st stage and a 2 nd stage, wherein the 1 st stage comprises a LCO hydrotreating (HT) zone and the 2 nd stage comprises a LCO hydrocracking (HC) zone wherein, 1) the LCO HT zone comprises a LCO HT reactor having a LCO HT catalyst and a 1 st stage high pressure separator (HPS) communicating with the LCO HT reactor and a LCO HC reactor in the LCO HC zone; 2) the LCO HC zone comprises a LCO reactor having a LCO HC catalyst and a 2 nd stage HPS and a hot flash seperator (HFS) disposed between and independently in fluid communication with the LOG HC reactor and the 2 nd stage HPS, and producing at least a first and second HFS product stream comprising liquid such that a portion of the liquid is recycled to the LCO HC reactor, wherein i) each HFS product stream comprises aromatic compounds and ULSD having a sulfur content of 10 wppm or less, ii) the at least the first HFS product stream is recycled to the LCO HC reactor, and iii) the at least the second HFS product stream is passed to a fractionation zone for recovering a first fractionation zone product stream comprising the aromatic compounds and a second fractionation zone product stream comprising ULSD.