Process for reducing content of sulphur compounds and poly-aromatic hydrocarbons in a hydrocarbon feed

Abstract

A process for reducing content of sulphur compounds and polyaromatic hydrocarbons in a hydrocarbon feed having a boiling range between 200° C. and 600° C., which process comprises in combination contacting the feed and hydrogen over a hydrotreating catalyst and hydrotreating feed at hydrotreating conditions, cooling the hydrotreated effluent and hydrogen-rich gas from the hydrotreating reactor contacting said effluent and hydrogen gas over a hydrotreating catalyst in a post-pretreatment reactor at a temperature sufficient to lower the polyaromatic hydrocarbon content.

1 . A process for reducing content of sulphur compounds and polyaromatic hydrocarbons in a hydrocarbon feed stock having a boiling range between 200° C. and 600° C., which process comprises the steps of 
 (a) contacting the feed stock with hydrogen over a hydrotreating catalyst at conditions being effective in hydrotreating and obtaining an hydrotreated effluent with the hydrotreated feed stock, hydrogen sulphide and hydrogen,  
 (b) cooling the effluent, and  
 (c) contacting the effluent with a hydrotreating catalyst at conditions being effective in hydrogenation of polyaromatic hydrocarbons.  
 
     
     
         2 . A process of    claim 1   , wherein the temperature in step (c) is between 50° C. and 150° C. lower than outlet temperature from step (a).  
     
     
         3 . A process of    claim 1   , wherein LHSV in step (c) is between 2 and 20 times the LHSV in step (a).  
     
     
         4 . A process of    claim 1   , wherein step (c) is performed in a final catalyst bed of the hydrotreating step.  
     
     
         5 . A process of    claim 1   , wherein the feedstock is characterised by having a 50% boiling point between 300° C. and 450° C.  
     
     
         6 . A process of    claim 1   , wherein the hydrotreating catalyst used in step (c) step is a composite of Group VI-B and/or Group VIII metal on a porous refractory inorganic oxide.  
     
     
         7 . A process of    claim 6   , wherein the metals are nickel and molybdenum or nickel and tungsten.  
     
     
         8 . A process of    claim 6   , wherein the porous refractory inorganic oxide is alumina or silica-alumina.