Steam integration in ethanol to jet fuel process

Abstract

An ethanol dehydration process is disclosed. The process comprises adding an amount of steam to a feed to the dehydration reactor to provide a charge stream. The steam stream is mixed with the feed to the dehydration reactor such that the steam to ethanol ratio is between about 0.5 to about 5.0 wt/wt. The charge stream is passed to a dehydration reactor to produce a dehydrated stream. Steam can be imported from outside the dehydration process such as from an oligomerization or dimerization reaction. Steam can be produced from the dehydrated stream.

1 . A process for operation of a dehydration reactor comprising adding an amount of steam to a feed to said dehydration reactor wherein said steam is taken from an oligomerization section of a hydrocarbon conversion plant. 
     
     
         2 . The process of  claim 1  wherein said steam is generated from a treated process water produced by a wastewater stripper and then said water is sent to at least one steam generator connected to an oligomerization reactor to produce steam and wherein a portion of said steam is sent to said dehydration reactor. 
     
     
         3 . The process of  claim 1  wherein a portion of feed water is blown down from each of said at least one steam generators. 
     
     
         4 . The process of  claim 1  wherein a portion of said steam is sent from a hydrogenation reactor. 
     
     
         5 . The process of  claim 1  wherein said steam cools down a hot effluent by a minimum amount up to about 187° C. 
     
     
         6 . The process of  claim 1  wherein a steam to alcohol ratio in said dehydration reactor is from about 0.3 to about 5.0 wt/wt. 
     
     
         7 . The process of  claim 1  wherein a portion of said steam is produced in a dedicated steam generator. 
     
     
         8 . The process of  claim 7  wherein said steam is further heated by exchanging heat with an olefin splitter bottoms stream in a steam superheater. 
     
     
         9 . The process of  claim 1  wherein a plurality of steam generators are used to generate said steam. 
     
     
         10 . The process of  claim 9  wherein a recycle oil steam generator cools down hot diesel coming from a flash stripper feed-recycle oil exchanger. 
     
     
         11 . The process of  claim 1 , wherein the oligomerization section comprises an oligomerization reactor comprising a first oligomerization reactor vessel and a second oligomerization reactor vessel. 
     
     
         12 . The process of  claim 11  further comprising an intercooler steam generator to remove heat of reaction from an oligomerized effluent stream before passing said oligomerized effluent stream to the second oligomerization reactor vessel. 
     
     
         13 . The process of  claim 11  further comprising an intercooler steam generator between oligomerization catalyst beds in the first oligomerization reactor vessel to remove heat of reaction from an oligomerized effluent stream of a top oligomerization catalyst bed of the first oligomerization reactor vessel. 
     
     
         14 . The process of  claim 11  further comprising an intercooler steam generator between oligomerization catalyst beds in the second oligomerization reactor vessel to remove heat of reaction from an oligomerized effluent stream of a top oligomerization catalyst bed of the second oligomerization reactor vessel. 
     
     
         15 . The process of  claim 1 , wherein the oligomerization section comprises a first stage oligomerization reactor and a second stage oligomerization reactor, and wherein an intercooler steam generator is provided to remove heat of reaction from an oligomerized effluent stream of the first stage oligomerization reactor before passing the oligomerized effluent stream to the second stage oligomerization reactor. 
     
     
         16 . A process for operation of a dehydration reactor comprising:
 adding a steam stream to a feed to said dehydration reactor to produce a charge stream;   dehydrating said charge stream to produce a dehydrated stream;   cooling said dehydrated stream to separate a water stream; and   producing said steam stream from said separated water stream.   
     
     
         17 . The process of  claim 16  further comprising passing said separated water stream to an oligomerization section to generate said steam stream. 
     
     
         18 . The process of  claim 17  further comprising:
 passing said separated water stream to a wastewater stripper to produce a stripped water stream; and 
 passing said stripped water stream to the oligomerization section to generate said steam stream. 
 
     
     
         19 . The process of  claim 16  further comprising heating said separated water stream with an olefin charge stream of the oligomerization section to generate said steam stream. 
     
     
         20 . A process for operation of a dehydration reactor, comprising:
 adding a steam stream to a feed to said dehydration reactor to produce a charge stream;   dehydrating said charge stream to produce a dehydrated stream;   cooling said dehydrated stream to separate a water stream; and   heating said separated water stream with an olefin charge stream of an oligomerization section to generate said steam stream.