Catalyst and a process for catalytic conversion of carbon dioxide-containing gas and hydrogen streams to hydrocarbons

Abstract

The invention relates to a catalyst suitable for use in the hydrogenation of carbon dioxide-containing gas, said catalyst comprising spinel phase of the formula [Fe 2+ (Fe 3+ y Al 3+ 1-y ) 2 O 4 ]. Processes for preparing the catalyst and processes for the hydrogenation of carbon dioxide-containing gas in the presence of the catalyst are also disclosed.

1 ) A process for preparing a compound of Formula 1:
   Fe 2+ (Fe 3+   y Al 3+   1-y ) 2 O 4   Formula 1
   wherein y is in the range from 0.25 to 0.75;   comprising dissolving in an aqueous solution at least one ferric compound and at least one aluminum compound to form a metal-containing solution, adjusting the pH of said metal-containing solution by means of gradual addition of an alkaline agent, whereby co-precipitation of the metals in the form of their hydroxides occurs, wherein the pH is adjusted within the range from 7 to 8.5, separating the solid formed from the liquid phase, and subjecting same to drying and calcination to obtain hematite-free spinel of Formula 1.   
     
     
         2 ) A process according to  claim 1 , wherein the addition time of the alkaline agent is not less than 10 minutes. 
     
     
         3 ) A process according to  claim 1 , wherein the alkaline agent is an aqueous solution of ammonium hydroxide. 
     
     
         4 ) A process according to  claim 3 , wherein the concentration of the ammonium hydroxide solution is not more than 5% by weight. 
     
     
         5 ) A process according to  claim 3 , wherein the metal-containing solution and the ammonium hydroxide solution are held at room temperature during the addition.