Process for preparing a high purity fischer-tropsch gasoil fraction

Abstract

The present invention provides a process for preparing a high purity Fischer-Tropsch gasoil fraction, comprising: a) providing a Fischer-Tropsch-derived gasoil feedstock comprising one or more contaminants; b) providing the Fischer-Tropsch-derived gasoil feedstock to a fractionation zone and fractionating the Fischer-Tropsch-derived gasoil feedstock into two or more Fischer-Tropsch gasoil fractions having a different boiling point range, wherein at least one Fischer-Tropsch gasoil fraction is a contaminant-enriched Fischer-Tropsch gasoil fraction, which is enriched in one or more contaminants with respect to the feedstock; c) providing the contaminant-enriched Fischer-Tropsch gasoil fraction to an absorption zone comprising at least one absorbent material and contacting the contaminant-enriched Fischer-Tropsch gasoil fraction with the absorbent material to absorb at least part of contaminant; and d) retrieving from the absorption zone a purified Fischer-Tropsch gasoil fraction, which is contaminant-depleted. The invention further provides for further processes for preparing a high purity Fischer-Tropsch gasoil fraction and the use of the purified Fischer-Tropsch gasoil fraction.

1 . A process for preparing a purified Fischer-Tropsch gasoil fraction, comprising:
 a) providing a Fischer-Tropsch-derived gasoil feedstock comprising one or more contaminants,   wherein said Fischer-Tropsch-derived gasoil is a fluid comprising paraffins, including isoparaffins and normal paraffins, with alkyl chain lengths in the range of from 7 to 30 carbon atoms, comprising at least 70 wt % of Fischer-Tropsch-derived paraffins having 9 to 25 carbon atoms based on the total amount of Fischer-Tropsch-derived paraffins;   b) providing the Fischer-Tropsch-derived gasoil feedstock to a fractionation zone and fractionating the Fischer-Tropsch-derived gasoil feedstock into two or more Fischer-Tropsch gasoil fractions having a different boiling point range, wherein at least one Fischer-Tropsch gasoil fraction is a contaminant-enriched Fischer-Tropsch gasoil fraction, which is enriched in one or more contaminants with respect to the feedstock;   c) providing the contaminant-enriched Fischer-Tropsch gasoil fraction to an absorption zone comprising at least one absorbent material and contacting the contaminant-enriched Fischer-Tropsch gasoil fraction with the absorbent material to absorb at least part of contaminant; and   d) retrieving from the absorption zone a purified Fischer-Tropsch gasoil fraction, which purified Fischer-Tropsch gasoil fraction is contaminant-depleted with respect to the contaminant-enriched Fischer-Tropsch gasoil fraction.   
     
     
         2 . A process according to  claim 1 , wherein the one or more contaminants are selected from the group consisting of oxygenate compounds and aromatics. 
     
     
         3 . A process according to  claim 1 , wherein at least one absorbent material is a molecular sieve material. 
     
     
         4 . A process according to  claim 1 , wherein the absorption zone comprises two or more absorbent materials. 
     
     
         5 . A process according to  claim 1 , wherein the contaminant-enriched Fischer-Tropsch gasoil fraction is contacted with the absorbent material at a temperature in the range of from 0 to 150° C. 
     
     
         6 . A process according to  claim 1 , wherein the contaminant-enriched Fischer-Tropsch gasoil fraction is contacted with the absorbent material in a fixed bed reactor comprising at least one fixed bed of absorbent material. 
     
     
         7 . A process according to  claim 1 , wherein the contaminant-enriched Fischer-Tropsch gasoil fraction has a final boiling point of no more than 260° C. 
     
     
         8 . A process according to  claim 1 , wherein the contaminant-enriched Fischer-Tropsch gasoil fraction has an initial boiling point of more than 260° C. 
     
     
         9 . A process according to  claim 1 , wherein the contaminant-enriched Fischer-Tropsch gasoil fraction has a Saybolt number below 30. 
     
     
         10 . A process according to  claim 1 , wherein the Fischer-Tropsch-derived gasoil has a final boiling point of no more than 450° C. 
     
     
         11 . A method of using a purified Fischer-Tropsch gasoil fraction obtained in the process of  claim 1  as a solvent, diluent or functional fluid. 
     
     
         12 . A process for preparing a purified Fischer-Tropsch gasoil fraction, comprising:
 i) providing a contaminant-comprising Fischer-Tropsch gasoil fraction, having a final boiling point of no more than 260° C. and wherein said Fischer-Tropsch gasoil fraction comprises more than 50 wt % of isoparaffins, to an absorption zone comprising at least one absorbent material and contacting the contaminant-comprising Fischer-Tropsch gasoil fraction with the absorbent material to absorb at least part of contaminant; and   ii) retrieving from the absorption zone a purified Fischer-Tropsch gasoil fraction, which purified Fischer-Tropsch gasoil fraction is contaminant-depleted with respect to the contaminant-comprising Fischer-Tropsch gasoil fraction.   
     
     
         13 . A method of using a purified Fischer-Tropsch gasoil fraction obtained in the process of  claim 12  as a solvent, diluent or functional fluid. 
     
     
         14 . A process for preparing a purified Fischer-Tropsch gasoil fraction, comprising:
 v) providing a contaminant-comprising Fischer-Tropsch gasoil fraction, having an initial boiling point of more than 260° C., to an absorption zone comprising at least one absorbent material and contacting the contaminant-comprising Fischer-Tropsch gasoil fraction with the absorbent material to absorb at least part of contaminant; and   vv) retrieving from the absorption zone a purified Fischer-Tropsch gasoil fraction, which purified Fischer-Tropsch gasoil fraction is contaminant-depleted with respect to the contaminant-comprising Fischer-Tropsch gasoil fraction.   
     
     
         15 . A method of using a purified Fischer-Tropsch gasoil fraction obtained in the process of  claim 14  as a solvent, diluent or functional fluid.