Process for preparing a paraffin product

Abstract

The invention is a process for preparing a paraffin product from a carbonaceous feedstock comprising (a) partial oxidation of the carbonaceous feedstock to obtain a mixture comprising hydrogen and carbon monoxide, (b) performing a Fischer-Tropsch reaction using the mixture as obtained in step (a) and recovering an off-gas from the Fischer-Tropsch reaction and a paraffin product, (c) hydrogenating at least a part of the off-gas from the Fischer-Tropsch reaction using a steam/off-gas mol ratio in the range of between 0.7 and 1.5 and a catalyst comprising copper and zinc and/or a catalyst comprising copper and manganese, and (d) preparing a hydrogen comprising gas from at least a part of the off-gas from the Fischer-Tropsch reaction.

What is claimed is: 
     
         1 . A process for preparing a paraffin product from a carbonaceous feedstock comprising the following steps,
 (a) partial oxidation of the carbonaceous feedstock to obtain a mixture comprising hydrogen and carbon monoxide,   (b) performing a Fischer-Tropsch reaction using the mixture as obtained in step (a) and recovering an off-gas from the Fischer-Tropsch reaction and a paraffin product,   (c) hydrogenating at least a part of the off-gas from the Fischer-Tropsch reaction using a steam/off-gas mol ratio in the range of between 0.7 and 1.5 and a catalyst comprising copper and zinc and/or a catalyst comprising copper and manganese, and   (d) preparing a hydrogen comprising gas from at least a part of the off-gas from the Fischer-Tropsch reaction.   
     
     
         2 . The process according to  claim 1 , wherein the steam/off-gas mol ratio is in the range of between 0.8 and 1.2. 
     
     
         3 . The process as claimed in  claim 1 , wherein hydrogenation step (c) is performed at a temperature in the range of between 200 and 300° C., preferably between 220 and 270° C. 
     
     
         4 . The process as claimed in  claim 1 , wherein hydrogenation step (c) is performed using two or more reactors comprising a copper comprising catalyst. 
     
     
         5 . The process as claimed in  claim 1 , wherein additionally a pre-reformer catalyst is used in step (c), the pre-reformer catalyst preferably comprising nickel. 
     
     
         6 . The process as claimed in  claim 5 , wherein the inlet temperature used for the pre-reformer catalyst is in the range of between 350 and 500° C. 
     
     
         7 . The process as claimed in  claim 5 , wherein the steam/dry gas molar ratio for the pre-reformer catalyst is in the range of between 0.5 and 1.5.