Process to prepare medicinal and technical white oils

Abstract

A process for the preparation of medicinal white oil or a technical white oil from a Fischer-Tropsch derived paraffinic distillate bottom product, wherein the bottom product is contacted with a heterogeneous adsorbent.

1 . A process for the preparation of medicinal white oil or a technical white oil from a Fischer-Tropsch derived paraffinic distillate bottom product, comprising contacting the bottom product with a heterogeneous adsorbent.  
   
   
       2 . The process of to  claim 1 , wherein the adsorbent comprises active carbon.  
   
   
       3 . The process of claims  1 , wherein a medicinal white oil is obtained having a kinematic viscosity at 100° C. of more than 8.5 cSt, a non-cyclic isoparaffins content of between 80 and 98 wt %, a Saybolt color of greater than +30, Ultra violet adsorption spectra values as measured by ASTM D 2269 of less than 0.70 in the 280-289 nm spectral band, of less than 0.60 in the 290-299 nm spectral band, of less than 0.40 in the 300-329 nm spectral band and of less than 0.09 in the 330-380 nm spectral band as according to FDA 178 3620 (′c).  
   
   
       4 . The process of  claim 1 , wherein said bottom product is obtained by a process comprising: 
 (a) hydrocracking/hydroisomerisating a Fischer-Tropsch derived feed, wherein weight ratio of compounds having at least 60 or more carbon atoms and compounds having at least 30 carbon atoms in the Fischer-Tropsch derived feed is at least 0.2 and wherein at least 30 wt % of compounds in the Fischer-Tropsch derived feed have at least 30 carbon atoms;    (b) separating the product of step (a) into one or more distillate fraction(s) of lower boiling fractions and a broad range base oil precursor fraction and a heavy fraction such that the T90 wt % boiling point of the base oil precursor fraction is between 350 and 550° C.;    (c) performing a pour point reducing step to the broad range base oil precursor fraction obtained in step (b); and,    (d) isolating a heavy bottom distillate fraction by distilling the product of step (c).    
   
   
       5 . A Fischer-Tropsch derived medicinal white oil having a kinematic viscosity at 100° C. of more than 8.5 cSt.  
   
   
       6 . The Fischer-Tropsch derived medicinal white oil of  claim 5 , having a noncyclic isoparaffins content of between 80 and 98 wt %, a Saybolt color of greater than +30, and Ultra violet adsorption spectra values as measured by ASTM D 2269 of less than 0.70 in the 280-289 nm spectral band, of less than 0.60 in the 290-299 nm spectral band, of less than 0.40 in the 300-329 nm spectral band and of less than 0.09 in the 330-380 nm spectral band as according to FDA 178 3620 (′c).