Catalyst and process for oxychlorination of ethylene to dichloroethane

Abstract

In an oxychlorination process of the type where ethylene is converted to 1,2-dichloroethane in the presence of a supported copper catalyst, the improvement comprising: the use of a supported catalyst prepared by (i) impregnating, within a first step, an alumina support with a first aqueous solution including copper, an alkaline earth metal, and an alkali metal to thereby form a first catalyst component; and (ii) impregnating, within a subsequent step, the first catalyst component with a second aqueous solution including copper and alkaline earth metal, where the second aqueous solution is substantially devoid of alkali metal, to thereby form the supported catalyst.

What is claimed is: 
     
         1 . A process for producing a catalyst for the oxychlorination of ethylene to 1,2-dichloroethane, the process comprising steps of:
 (i) impregnating, within a first step, an alumina support with a first aqueous solution including copper, magnesium, and potassium to thereby form a first catalyst component, wherein the first aqueous solution provides the first catalyst component with a potassium concentration of greater than 0.5 weight percent; and   (ii) impregnating, within a subsequent step, the first catalyst component with a second aqueous solution including copper and magnesium, where the second aqueous solution is substantially devoid of potassium, to thereby form the supported catalyst, where said second aqueous solution includes a magnesium to copper molar ratio of greater than 0.19, wherein the concentration of the potassium within the second aqueous solution is less than that amount that would provide the supported catalyst with an additional potassium concentration of 0.5 weight percent.   
     
     
         2 . The process of  claim 1 , where said second aqueous solution includes a magnesium to copper molar ratio of from 0.20 to 0.50. 
     
     
         3 . An oxychlorination process where ethylene is converted to 1,2-dichloroethane in the presence of the catalyst of  claim 1 . 
     
     
         4 . The process of  claim 3 , where the oxychlorination process is conducted within a fluid-bed reactor. 
     
     
         5 . The process of  claim 4 , where the fluid bed reactor is a baffled-bed reactor, and where the second aqueous solution includes an alkaline earth metal to copper molar ratio of from 0.20 to 0.50, and where the molar ratio of oxygen to hydrogen chloride (O 2 /2HCl) of the oxychlorination process is less than 0.54. 
     
     
         6 . The process of  claim 1 , where the supported catalyst includes from about 5.0 to about 12 weight percent of the copper, based upon a total weight of the catalyst. 
     
     
         7 . The process of  claim 1 , where the supported catalyst includes from about 0.25 to about 1.6 weight percent of the magnesium, and where the supported catalyst further includes from about 0.5 to about 2.25 weight percent rare earth metal, based upon a total weight of the catalyst. 
     
     
         8 . The process of  claim 1 , where the second aqueous solution is devoid of alkali metal. 
     
     
         9 . The process of  claim 1 , where the supported catalyst includes a total amount of potassium from 1.05 to 1.6 weight percent, based upon a total weight of the catalyst. 
     
     
         10 . A process for producing a catalyst for the oxychlorination of ethylene to 1,2-dichloroethane, the process comprising steps of:
 (i) impregnating, within a first step, an alumina support with a first aqueous solution including copper, magnesium, and potassium to thereby form a first catalyst component; and   (ii) impregnating, within a subsequent step, the first catalyst component with a second aqueous solution including copper and magnesium, where the second aqueous solution is substantially devoid of potassium, to thereby form the supported catalyst, where said second aqueous solution includes a magnesium to copper molar ratio of greater than 0.19.   
     
     
         11 . The process of  claim 10 , where said second aqueous solution includes a magnesium to copper molar ratio of from 0.20 to 0.50, where the first aqueous solution provides the first catalyst component with a potassium concentration of greater than 0.25 weight percent, and where the concentration of the potassium within the second aqueous solution is less than that amount that would provide the supported catalyst with an additional potassium concentration of 0.3 weight percent, based upon a total weight of the catalyst. 
     
     
         12 . The process of  claim 11 , where the first aqueous solution provides the first catalyst component with a potassium concentration of greater than 1.0 weight percent, and where the concentration of the potassium within the second aqueous solution is less than that amount that would provide the supported catalyst with an additional potassium concentration of 0.1 weight percent, based upon a total weight of the catalyst. 
     
     
         13 . The process of  claim 11 , where the first aqueous solution further includes rare earth metal. 
     
     
         14 . An oxychlorination process where ethylene is converted to 1,2-dichloroethane in the presence of the catalyst of  claim 10 . 
     
     
         15 . The process of  claim 14 , where the oxychlorination process is conducted within a fluid-bed reactor. 
     
     
         16 . The process of  claim 15 , where the fluid bed reactor is a baffled-bed reactor, and where the second aqueous solution includes an alkaline earth metal to copper molar ratio of from 0.20 to 0.50, and where the molar ratio of oxygen to hydrogen chloride (O 2 /2HCl) of the oxychlorination process is less than 0.54. 
     
     
         17 . A process for producing a catalyst for the oxychlorination of ethylene to 1,2-dichloroethane, the process comprising steps of:
 (i) impregnating, within a first step, an alumina support with a first aqueous solution including copper, an alkaline earth metal, and an alkali metal to thereby form a first catalyst component, wherein the first aqueous solution provides the first catalyst component with an alkali metal concentration of greater than 1.05 weight percent; and   (ii) impregnating, within a subsequent step, the first catalyst component with a second aqueous solution including copper and an alkaline earth metal, where the second aqueous solution is substantially devoid of alkali metal, to thereby form the supported catalyst, where said second aqueous solution includes an alkaline earth metal to copper molar ratio of greater than 0.19, wherein the concentration of the alkali metal within the second aqueous solution is less than that amount that would provide the supported catalyst with an additional alkali metal concentration of 0.3 weight percent.   
     
     
         18 . The process of  claim 17 , where the alkaline earth metal in the first aqueous solution and the second aqueous solution is magnesium, and where the alkali metal is potassium. 
     
     
         19 . The process of  claim 17 , where the supported catalyst further includes from about 0.5 to about 2.25 weight percent rare earth metal, based upon a total weight of the catalyst. 
     
     
         20 . An oxychlorination process where ethylene is converted to 1,2-dichloroethane in the presence of the catalyst of  claim 17 .