Process for converting olefins to jet fuel

Abstract

A process for dimerizing and oligomerizing olefins to distillate fuels which subjects oligomerized product to hydrocracking and perhaps hydroisomerization to convert heavier oligomers to jet fuel range oligomers. A jet fuel product stream may be taken from a side of a stripping column which produces a heavy drag stream from a bottom of the stripping column to ensure an end point boiling specification is achieved.

1 . A process for oligomerizing an olefin stream comprising:
 dimerizing said olefin stream with a first-stage oligomerization catalyst to produce a first-stage oligomerized olefin stream;   oligomerizing said first-stage oligomerized olefin stream with a second-stage oligomerization catalyst to provide a second-stage oligomerized stream; and   cracking said second-stage oligomerized stream to provide a cracked oligomerized stream.   
     
     
         2 . The process of  claim 1  further comprising hydrogenating said second-stage oligomerized olefin stream before cracking said second-stage oligomerized stream. 
     
     
         3 . The process of  claim 1  further comprising separating said second-stage oligomerized stream into a light oligomerized stream and a heavy oligomerized stream and cracking said heavy oligomerized stream. 
     
     
         4 . The process of  claim 3  further comprising hydrogenating said heavy oligomerized stream before cracking said heavy oligomerized stream. 
     
     
         5 . The process of  claim 1  further comprising hydroisomerizing said second-stage oligomerized stream to provide said cracked oligomerized stream. 
     
     
         6 . The process of  claim 1  further comprising separating said cracked oligomerized stream to provide a vaporous cracked oligomerized stream and a liquid cracked oligomerized stream. 
     
     
         7 . The process of  claim 6  further comprising stripping said liquid cracked oligomerized stream to provide a green jet stream. 
     
     
         8 . The process of  claim 7  further comprising recycling a portion of said green jet stream to said dimerizing step. 
     
     
         9 . The process of  claim 7  further comprising stripping said liquid cracked oligomerized stream to provide a heavy drag stream. 
     
     
         10 . The process of  claim 8  further comprising cooling and separating said vaporous cracked oligomerized stream to provide a cold vaporous cracked oligomerized stream and a cold liquid cracked oligomerized stream and stripping said cold liquid cracked oligomerized stream with said liquid oligomerized stream. 
     
     
         11 . A process for oligomerizing an olefin stream comprising:
 dimerizing said olefin stream with a first-stage oligomerization catalyst to produce a first-stage oligomerized olefin stream;   oligomerizing said first-stage oligomerized olefin stream with a second-stage oligomerization catalyst to provide a second-stage oligomerized olefin stream;   hydrogenating said second-stage oligomerized olefin stream to provide a hydrogenated oligomerized stream; and   cracking said hydrogenated oligomerized stream to provide a cracked oligomerized stream.   
     
     
         12 . The process of  claim 11  further comprising separating said second-stage oligomerized olefin stream into a light oligomerized olefin stream and a heavy oligomerized olefin stream and hydrogenating said heavy oligomerized olefin stream. 
     
     
         13 . The process of  claim 11  further comprising hydroisomerizing said second-stage oligomerized stream to provide said cracked oligomerized stream. 
     
     
         14 . The process of  claim 11  further comprising separating said cracked oligomerized stream to provide a vaporous cracked oligomerized stream and a liquid cracked oligomerized stream. 
     
     
         15 . The process of  claim 14  further comprising stripping said liquid cracked oligomerized olefin stream to provide a green jet stream. 
     
     
         16 . The process of  claim 15  further comprising recycling a portion of said green jet stream to said dimerizing step. 
     
     
         17 . The process of  claim 15  further comprising stripping said liquid cracked oligomerized stream to provide a heavy drag stream. 
     
     
         18 . The process of  claim 16  further comprising cooling and separating said vaporous cracked oligomerized stream to provide a cold vaporous cracked oligomerized stream and a cold liquid vaporous cracked oligomerized stream and stripping said cold liquid cracked oligomerized stream with said liquid oligomerized stream. 
     
     
         19 . A process for oligomerizing an olefin stream comprising:
 dimerizing said olefin stream with a first-stage oligomerization catalyst to produce a first-stage oligomerized olefin stream;   oligomerizing said first-stage oligomerized olefin stream with a second-stage oligomerization catalyst to provide a second-stage oligomerized olefin stream;   hydrogenating said second-stage oligomerized olefin stream to provide a hydrogenated oligomerized stream; and   cracking and isomerizing said hydrogenated oligomerized stream to provide a cracked oligomerized stream.   
     
     
         20 . The process of  claim 19  further comprising separating said second-stage oligomerized olefin stream into a light oligomerized olefin stream and a heavy oligomerized olefin stream and hydrogenating said heavy oligomerized olefin stream.