Fischer-Tropsch product condensing process for cold climates

Abstract

A process to optimize the condensation of Fischer-Tropsch products coming from the Fischer-Tropsch reactor in a vapour phase with the use of light oil and, therefore; reducing the possibility of coating the coolers and piping with waxy material.

1 . A process for condensing Fischer-Tropsch products comprising the steps of: 
 (a) passing FTR gasses through a conduit located within a Ficher-Tropsh reactor wherein the conduit is situated substantially vertically within the reactor, has a first open end which is situated with the reactor headspace, and which directs the FTR gasses downward and out of the FTR;    (b) feeding the FTR gasses into a first scrubber;    (c) withdrawing a first overhead stream from the first scrubber;    (d) feeding the first overhead stream into a second scrubber wherein the second scrubber is capable of separating two liquid phases;    (e) recovery from the second scrubber an organic liquid phase comprising a light hydrocarbon oil; and    (f) directing a portion of the light hydrocarbon oil to the first scrubber and recycling a portion of the light hydrocarbon oil back into the second scrubber.    
   
   
       2 . The process of  claim 1  further comprising the step of: 
 withdrawing a second overhead stream from the second scrubber.    
   
   
       3 . The process of  claim 2  further comprising the steps of: 
 feeding the second overhead stream into a third scrubber wherein the third scrubber is capable of separating two liquid phases; and    recovering from the third scrubber a second light hydrocarbon oil stream.    
   
   
       4 . The process of  claim 3  further comprising the steps of: 
 directing a least a portion of the second light hydrocarbon oil stream into either the first, second or third scrubber.    
   
   
       5 . The process of  claim 1  further comprising the steps of: 
 recovering a heavier hydrocarbon stream from the first scrubber.    
   
   
       6 . The process of  claim 1  further comprising the step of: 
 recovering an aqueous liquid stream comprising FT-produced water from the second scrubber.    
   
   
       7 . The process of  claim 3  further comprising the step of: 
 recovering an aqueous liquid stream comprising FT-produced water from the third scrubber.    
   
   
       8 . The process of  claim 1  wherein the first overhead stream contains substantially no hydrocarbons having a carbon number greater than 18.  
   
   
       9 . The process of  claim 5  wherein the heavier hydrocarbon stream contains substantially no hydrocarbons having a carbon number less than 16.  
   
   
       10 . The process of  claim 3  further comprising the steps of: 
 removing a third overhead stream from the third scrubber; and    feed the third overhead stream to a synthesis gas generation system.    
   
   
       11 . The process of  claim 2  wherein the second overhead stream is cooled to a temperature greater than the freezing point of FT-produced water entrained in the second overhead  3  stream.  
   
   
       12 . The process of  claim 1  further comprising the steps of: 
 cooling the first light hydrocarbon oil stream to a temperature between 30 and 70° F. from the second scrubber prior to feeding into the first scrubber.    
   
   
       13 . The process of  claim 1  wherein a portion of the first light hydrocarbon stream is further processed into a product stream.  
   
   
       14 . The process of  claim 3  wherein a portion of the second light hydrocarbon stream is further processed into a product stream.  
   
   
       15 . A process for condensing Fischer-Tropsch products comprising the steps of 
 (a) passing FTR gasses through a conduit located within a Fischer-Tropsch reactor wherein the conduit is situated substantially vertically within the reactor, has a first open end which directs the FTR gasses downward and out of the FTR;    (b) injecting a light hydrocarbon oil stream into the FTR gasses;    (c) feed the FTR gasses into a flush drum; and    (d) withdrawing a first overhead stream consisting essentially of hydrocarbons having a carbon number of less than 16 from the flush drum.