Conversion of LPG hydrocarbons into distillate fuels using an integral LPG dehydrogenation-MOGD process

Claim 1

A process for converting lower paraffinic hydrocarbon feedstock comprising propane and/or butane into heavier hydrocarbons comprising gasoline and distillate, comprising the steps of: feeding the paraffinic feedstock to a dehydrogenation zone under conversion conditions for dehydrogenating at least a portion of said feedstock; recovering a first dehydrogenation gaseous effluent stream comprising propene and/or butene; contacting said first gaseous effluent steam with a liquid lean oil sorbent stream comprising C 5 + hydrocarbons under sorption conditions to produce a C 3 + rich liquid absorber stream and a light gas stream; sequentially pressurizing, heating and passing said C 3 + rich liquid absorber stream to an oligomerization reactor zone at elevated temperature and pressure; contacting said C 3 + rich stream with oligomerization catalyst in said oligomerization reactor zone for conversion of at least a portion of lower olefins to heavier hydrocarbons under oligomerization reaction conditions to provide a second reactor effluent stream comprising gasoline and distillate boiling range hydrocarbons; flash separating said second reactor effluent stream into a separator vapor stream comprising a major portion of said hydrocarbons which later form said lean oil stream, and a major portion of the C 4 - hydrocarbons and a separator liquid stream comprising said gasoline and distillate boiling range materials produced in said oligomerization reactor zone; fractionating said separator liquid stream in a first product debutanizer tower into a first debutanizer overhead vapor stream comprising C 4 - hydrocarbons and a product debutanizer liquid bottoms stream comprising C 5 + gasoline and distillate boiling range hydrocarbons; further fractionating said product debutanizer liquid stream in a product splitter tower to provide a gasoline product stream and a distillate product stream; fractionating said separator vapor stream in a second recycle debutanizer tower into a second debutanizer overhead vapor stream comprising C 4 - hydrocarbons and a C 5 + liquid recycle stream comprising; recycling said first and second debutanizer overhead vapor streams to said dehydrogenation reactor zone for further conversion; and passing at least a portion of the liquid recycle stream from the second debutanizer tower for use as said liquid lean oil sorbent stream; thereby minimizing lean oil to said product debutanizer and said product splitter downstream.