초록 ▼

A hydrocracking process wherein the undesirable production of polynuclear aromatic compounds is controlled by removing a small dragstream of high pressure product stripper bottoms to reject polynuclear aromatic compounds and recovering valuable diesel boiling range hydrocarbons and unconverted feeds

A hydrocracking process wherein the undesirable production of polynuclear aromatic compounds is controlled by removing a small dragstream of high pressure product stripper bottoms to reject polynuclear aromatic compounds and recovering valuable diesel boiling range hydrocarbons and unconverted feedstock by routing the dragstream to a hot flash separator and subsequently to a divided wall fractionation zone to produce a concentrated stream of polynuclear aromatic compounds while recovering the valuable hydrocarbon compounds.

대표청구항 ▼

1. A process for hydrocracking a hydrocarbonaceous feedstock which process comprises:(a) passing a hydrocarbonaceous feedstock, a hydrocracking zone effluent and hydrogen to a denitrification and desulfurization reaction zone containing a catalyst and recovering a denitrification and desulfurization

1. A process for hydrocracking a hydrocarbonaceous feedstock which process comprises:(a) passing a hydrocarbonaceous feedstock, a hydrocracking zone effluent and hydrogen to a denitrification and desulfurization reaction zone containing a catalyst and recovering a denitrification and desulfurization reaction zone effluent therefrom; (b) passing said denitrification and desulfurization reaction zone effluent directly to a hot, high pressure stripper utilizing a hot hydrogen-rich stripping gas to produce a first vapor stream comprising hydrogen, hydrocarbonaceous compounds boiling at a temperature below the boiling range of said hydrocarbonaceous feedstock, hydrogen sulfide and ammonia, and a first liquid stream comprising hydrocarbonaceous compounds boiling in the range of said hydrocarbonaceous feedstock; (c) passing at least a portion of said first liquid stream comprising hydrocarbonaceous compounds boiling in the range of said hydrocarbonaceous feedstock and hydrogen to a hydrocracking zone containing a hydrocracking catalyst and recovering a hydrocracking zone effluent therefrom; (d) passing said hydrocracking zone effluent to said denitrification and desulfurization reaction zone; (e) passing said first vapor stream comprising hydrogen, hydrocarbonaceous compounds boiling at a temperature below the boiling range of said hydrocarbonaceous feedstock, hydrogen sulfide and ammonia to an aromatic saturation zone containing hydrogenation catalyst to produce a second liquid stream comprising hydrocarbonaceous compounds boiling at a temperature below the boiling range of said hydrocarbonaceous feedstock and having a reduced concentration of aromatic compounds; (f) passing at least a portion of said second liquid stream produced in step (e) to a first zone of a divided wall fractionation zone to recover at least a portion of said hydrocarbonaceous compounds boiling at a temperature below the boiling range of said hydrocarbonaceous feedstock; and (g) passing hydrocarbonaceous compounds boiling in the range of said hydrocarbonaceous feedstock and polynuclear aromatic compounds from the bottom of the hot, high pressure stripper to a second zone of said divided wall fractionation zone to produce a third liquid stream comprising polynuclear aromatic compounds.