Process for the production of jet-range hydrocarbons

Abstract

A method for producing jet-range hydrocarbons includes passing a renewable olefin feedstock comprising C 3 to C 8 olefins to an oligomerization reactor containing a zeolite catalyst to produce an oligomerized effluent, separating the oligomerized effluent into at least a C 7 − hydrocarbon stream, a heavy olefin stream, and a jet range olefin stream. At least a portion of the heavy olefin stream is recycled to the oligomerization reactor to dilute the renewable C 4 olefin feedstock. The jet range olefin stream may be hydrotreated and separated to provide a jet range hydrocarbon product.

1 . A process for producing jet range hydrocarbons comprising:
 oligomerizing a renewable olefin feedstock comprising C 3  to C 8  olefins in an oligomerization reactor containing a catalyst comprising a MTT zeolite that has not been selectivated, and operating the oligomerization reactor under conditions to produce an oligomerized effluent;   separating the oligomerized effluent to produce a light hydrocarbon stream, a naphtha olefin hydrocarbon stream, and a heavy stream comprising C 8+  olefins; and,   separating the heavy stream into jet range olefin stream and an olefin recycle stream comprising diesel range olefins; and,   diluting the renewable olefin feedstock with at least a portion of the olefin recycle stream.   
     
     
         2 . The process of  claim 1  further comprising:
 blending a portion of the olefin recycle stream in a diesel blending pool. 
 
     
     
         3 . The process of  claim 2  further comprising:
 hydrogenating the portion of the olefin recycle stream blended in the diesel blending pool before blending. 
 
     
     
         4 . The process of  claim 1  further comprising:
 recycling at least a portion of the naphtha olefin hydrocarbon stream to the oligomerization reactor. 
 
     
     
         5 . The process of  claim 1  further comprising:
 hydrogenating the jet range olefin stream in a hydrogenation zone having a hydrogenating reactor to provide a hydrogenated effluent. 
 
     
     
         6 . The process of  claim 5  further comprising:
 separating the hydrogenated effluent into a vent gas stream and a jet range hydrocarbons stream. 
 
     
     
         7 . The process of  claim 6  further comprising:
 recycling at least a portion of the jet range hydrocarbons stream to the hydrogenation zone. 
 
     
     
         8 . A process for producing jet range hydrocarbons comprising:
 passing a renewable olefin feedstock comprising C 3  to C 8  olefins to an oligomerization reaction zone comprising an oligomerization reactor containing a catalyst comprising a non-selectivated MTT zeolite and wherein said oligomerization reactor is operating under conditions to produce an oligomerized effluent;   passing the oligomerized effluent to a first separation zone to provide at least one stream comprising C 7−  hydrocarbons, a diesel range olefin recycle stream, and a jet range olefin stream; and,   recycling at least a first portion of the diesel range olefin recycle stream to the oligomerization reaction zone.   
     
     
         9 . The process of  claim 8  further comprising:
 combining the first portion of the diesel range olefin recycle stream with the renewable olefin feedstock to provide a combined stream; and, 
 passing the combined stream into the oligomerization reactor. 
 
     
     
         10 . The process of  claim 8  further comprising:
 passing a second portion of the diesel range olefin recycle stream to a diesel blending pool. 
 
     
     
         11 . The process of  claim 10  further comprising:
 hydrogenating the second portion of the diesel range olefin recycle stream before it is passed to the diesel blending pool. 
 
     
     
         12 . The process of  claim 8  wherein the first separation zone produces a light hydrocarbon stream and a naphtha olefin hydrocarbon stream. 
     
     
         13 . The process of  claim 12 , wherein the first separation zone comprises two fractionation columns. 
     
     
         14 . The process of  claim 13 , wherein the first fractionation column provides the light hydrocarbon stream, the naphtha olefin hydrocarbon stream, and wherein the second fractionation column provides the diesel range olefin recycle stream and the jet range olefin stream. 
     
     
         15 . The process of  claim 14  further comprising:
 passing at least a portion of the naphtha olefin hydrocarbon stream to the oligomerization reactor. 
 
     
     
         16 . The process of  claim 8  further comprising:
 passing the jet range olefin stream to a hydrogenation zone having a hydrogenating reactor containing a catalyst and being operated to provide a hydrogenated effluent. 
 
     
     
         17 . The process of  claim 16  further comprising:
 passing the hydrogenated effluent to second separation zone to provide a vent gas stream and a jet range hydrocarbons stream. 
 
     
     
         18 . The process of  claim 17  further comprising:
 passing at least a portion of the jet range hydrocarbons stream to the hydrogenating reaction zone as a recycle jet range stream. 
 
     
     
         19 . The process of  claim 18  further comprising:
 combining the recycle jet range stream and the jet range olefin stream in a jet range combined stream; and, 
 passing the jet range combined stream to the hydrogenating reactor. 
 
     
     
         20 . The process of  claim 8  wherein the first separation zone comprises at least two fractionation columns arranged in series.