Catalyst and process for preparing chlorine by gas phase oxidation of hydrogen chloride

Abstract

The present invention relates to a catalyst and to a process for preparing chlorine by catalytic oxidation of hydrogen chloride. The catalyst comprises an active component and a support material, said active component comprising at least uranium or a uranium compound. The catalyst is notable for a high stability and activity at a lower cost compared to the noble metals.

1 . A catalyst for catalytic oxidation of hydrogen chloride, comprising as catalytically active components, at least uranium or a uranium compound and a support material. 
   
   
       2 . The catalyst according to  claim 1 , wherein the support comprises UO 3 , UO 2 , UO or nonstoichiometric phases resulting from mixtures of the following species: U 3 O 5 , U 2 O 5 , U 3 O 7 , U 3 O 8 , U 4 O 9 , U 13 O 34 . 
   
   
       3 . The catalyst according to  claim 1 , wherein the uranium or the uranium compound is present in the form of uranium oxide or a mixture of uranium oxides with a stoichiometric composition of UO 2.1  to UO 2.9 . 
   
   
       4 . The catalyst according to  claim 1 , comprising further substances suitable as catalytically active components, selected from the group consisting of ruthenium, osmium, rhodium, iridium, palladium, platinum, copper, silver, gold, rhenium, bismuth, cobalt, iron, antimony, tin, manganese, chromium, mixtures thereof, and chemical compounds comprising at least one of the abovementioned elements in the list. 
   
   
       5 . The catalyst according to  claim 1 , wherein the support material is selected from the group consisting of silicon dioxide, aluminium oxide, titanium dioxide, tin dioxide, zirconium dioxide, cerium dioxide, carbon nanotubes, and mixtures thereof. 
   
   
       6 . A process for preparing chlorine comprising the step of catalytically oxidizing hydrogen chloride in the presence of a catalyst, said catalyst comprising an active component and a support material, and wherein the active component comprises uranium or a uranium compound. 
   
   
       7 . The process according to  claim 6 , wherein the uranium or the uranium compound is present in the form of uranium oxide or a mixture of uranium oxides having a stoichiometric composition of UO 2.1  to UO 2.9 . 
   
   
       8 . The process according to  claim 6 , wherein the proportion of the active component is in the range of 0.1 to 90% by weight, based on the total mass of active component and support material. 
   
   
       9 . The process according to  claim 6 , wherein the reaction temperature is 150 to 750° C. 
   
   
       10 . The process according to  claim 6 , wherein the reaction pressure is 1 to 25 bar. 
   
   
       11 . The process according to  claim 6 , wherein it is performed isothermally or adiabatically, continuously and as a fixed bed process. 
   
   
       12 . The process according to  claim 6 , wherein the process is performed in two or more stages, in 2 to 10 reactors connected in series with intermediate cooling. 
   
   
       13 . The process according to  claim 6 , wherein the volume ratio of hydrogen chloride to oxygen at the reactor inlet is between 1:1 and 20:1. 
   
   
       14 . The process according to  claim 12  wherein the process is performed in two or more stages in 2 to 3 reactors connected in series with intermediate cooling. 
   
   
       15 . The process according to  claim 13  wherein the volume ratio of hydrogen chloride to oxygen at the reactor inlet is between 2:1 and 5:1.