Process for preparing benzene

Abstract

The present invention relates to a process for the endothermic, catalytic gas phase reaction of naphtha with hydrogen to form benzene, in which the reaction is carried out in 5 to 12 serial reaction zones under adiabatic conditions.

1 . Process for preparing benzene from naphtha in the presence of hydrogen in an endothermic, heterogeneously catalytic gas phase reaction, which comprises 5 to 12 serial reaction zones with adiabatic conditions. 
     
     
         2 . Process according to  claim 1 , wherein the conversion takes place in 6 to 10 serial reaction zones. 
     
     
         3 . Process according to  claim 1 , wherein the entry temperature of the process gas entering the first reaction zone is 740 to 790 K. 
     
     
         4 . Process according to  claim 1 , wherein the absolute pressure at the entry of the first reaction zone is between 10 and 40 bar. 
     
     
         5 . Process according to  claim 1 , wherein the residence time of the process gas in all reaction zones is between 0.5 and 30 s. 
     
     
         6 . Process according to  claim 1 , wherein the catalysts are present in a fixed bed arrangement. 
     
     
         7 . Process according to  claim 6 , wherein the catalysts are present in the form of monoliths. 
     
     
         8 . Process according to  claim 7 , wherein the monolith comprises channels having a diameter of 0.1 to 3 mm. 
     
     
         9 . Process according to  claim 1 , wherein the catalysts are present in beds of particles having average particles sizes of 1 to 10 mm. 
     
     
         10 . Process according to  claim 1 , wherein at least one reaction zone is followed by at least one heat exchange zone through which the process gas is passed. 
     
     
         11 . Process according to  claim 10 , wherein each reaction zone is followed by at least one heat exchange zone through which the process gas is passed. 
     
     
         12 . Process according to  claim 1 , wherein between a reaction zone and a heat exchange zone there is at least one heat insulation zone. 
     
     
         13 . Process according to  claim 12 , wherein around each reaction zone there is a heat insulation zone.