selective nickel based hydrogenation catalyst and the preparation thereof

Abstract

A selective nickel-based hydrogenation catalyst with alumina as carrier and the preparation thereof, characterized in that: provided that the catalyst is weighed 100%, it comprises nickel oxide 14-20% as active component, lanthanum oxide and/or cerium oxide 1-8%, VIB element oxide 1-8% as aids, 2-8% silica, 1-8% alkaline earth metal oxides. The catalyst specific surface area is 60-150 m 2 /g, and the pore volume is 0.4-0.6 ml/g. The catalyst has good hydrogenation performance, especially impurity and colloid resistance and hydrogenation stability. The catalyst can be applied to the diolefin selective hydrogenation of medium or low-distillate oil, especially of the full-distillates pyrolysis gasoline.

1 . A selective nickel-based hydrogenation catalyst comprising alumina as a carrier, characterized in that based on the total weight of the catalyst, the catalyst comprises:
 14-20% nickel oxide as an active component;   1-8% lanthanum oxide and/or cerium oxide;   1-8% VIB group element oxide as aids;   2-8% silica; and   1-8% alkaline earth metal oxide;   wherein said catalyst has a specific surface area of 60-150 m 2 /g and a pore volume of 0.4-0.6 ml/g.   
     
     
         2 . The selective nickel-based hydrogenation catalyst according to  claim 1 , characterized in that the nickel oxide in the catalyst is in the amount of 15-19%. 
     
     
         3 . The selective nickel-based hydrogenation catalyst according to  claim 1 , characterized in that the lanthanum oxide and/or cerium oxide in the catalyst is in the amount of 3-5%. 
     
     
         4 . The selective nickel-based hydrogenation catalyst according to  claim 1 , characterized in that said alkaline earth metal is magnesium and/or strontium. 
     
     
         5 . The selective nickel-based hydrogenation catalyst according to  claim 1 , characterized in that the alkaline earth metal oxide in the catalyst is in the amount of 2-5%. 
     
     
         6 . The selective nickel-based hydrogenation catalyst according to  claim 1 , characterized in that said VIB group element is one or more selected from the group consisting of chromium, molybdenum and tungsten. 
     
     
         7 . The selective nickel-based hydrogenation catalyst according to  claim 1 , characterized in that the VIB group element oxide in the catalyst is in the amount of 3-6%. 
     
     
         8 . A method for preparing the selective nickel-based hydrogenation catalyst according to  claim 1 , comprising:
 adding silica or its precursor and alkaline earth metal oxide or its precursor into an alumina carrier so as to form a first mixture;   calcinating the first mixture at the temperature of 800-1100° C. for 3-6 hours to form a modified alumina carrier;   adding soluble salts of nickel, rare earth element and VIB group element into water so as to form a solution;   adjusting the pH of the solution to 4-5 following full dissolution of the soluble salts to form an impregnating solution;   impregnating the modified alumina carrier with the impregnating solution to form a second mixture;   after impregnating, drying the second mixture at the temperature of 40-120° C.; and   after drying, calcinating the second mixture at the temperature of 350-450° C. for 3-6 hours, thereby obtaining the resultant catalyst.   
     
     
         9 . The method according to  claim 8 , characterized in that the modified alumina carrier is prepared by:
 adding silica sol, nitric acid and water into alumina hydrate so as to form a third mixture;   after kneading and extruding the third mixture, drying the third mixture at the temperature of 40-120° C.;   after drying, calcinating the third mixture at the temperature of 300-600° C. for 4-6 hours so as to form a carrier;   impregnating the carrier with an impregnating solution formed by adding alkaline earth metal oxide into water;   after impregnating, drying the carrier at the temperature of 40-120° C.; and   after drying, calcinating the carrier at the temperature of 800-1100° C. for 4-6 hours, thereby forming the modified alumina carrier.