Process for the conversion of ethylene to vinyl chloride, and novel catalyst compositions useful for such process

Abstract

This invention is a process for producing vinyl chloride from an ethylene-containing feed, oxygen, and a chlorine source in the presence of a catalyst. The process permits direct production of vinyl chloride in a single reactor system, and further permits ethane to be used as the C 2 hydrocarbon feed with recycle of ethylene from the product stream to constitute the ethylene specified for the feed. This invention in another aspect concerns also a composition of matter, and a method for making the composition, wherein the composition is useful as a catalyst for the vinyl chloride process. The composition comprises a rare earth-containing material, with the proviso that the catalyst prepared therefrom is substantially free of iron and copper and with the further proviso that when cerium is present the catalyst further comprises at least one more rare earth element other than cerium.

1 . A catalytically useful composition of the formula MOCl, wherein M is at least one rare earth element selected from the group consisting of lanthanum, cerium, neodymium, praseodymium, dysprosium, samarium, yttrium, gadolinium, erbium, ytterbium, holmium, terbium, europium, thulium and lutetium, with the proviso that when cerium is present, at least one more rare earth element other than cerium is also present; the catalyst having a BET surface area of at least 12 m 2 /g.  
     
     
         2 . The composition of  claim 1 , wherein M is a mixture of at least two rare earth elements selected from the group consisting of lanthanum, cerium, neodymium, praseodymium, dysprosium, samarium, yttrium, gadolinium, erbium, ytterbium, holmium, terbium, europium, thulium and lutetium.  
     
     
         3 . The composition of  claim 1 , with the proviso that the composition is substantially free of iron and copper.  
     
     
         4 . The composition of  claim 1 , as deposited on an inert support.  
     
     
         5 . The composition of 1, wherein the composition is a porous, bulk material.  
     
     
         6 . The composition of  claim 1  wherein the BET surface area of the composition is at least 30 m 2 /g.  
     
     
         7 . The composition of  claim 1 , as prepared by a method comprising the following steps: 
 (a) preparing a solution of a chloride salt of the rare earth element or elements in a solvent comprising either water, an alcohol, or mixtures thereof;    (b) adding a nitrogen-containing base to cause the formation of a precipitate; and    (c) collecting, drying and calcining the precipitate in order to form the MOCl composition.    
     
     
         8 . A catalytically-useful composition of the formula MCl 3  wherein M is at least one rare earth element selected from the group consisting of lanthanum, cerium, neodymium, praseodymium, dysprosium, samarium, yttrium, gadolinium, erbium, ytterbium, holmium, terbium, europium, thulium and lutetium with the proviso that when cerium is present, at least one more rare earth element other than cerium is also present; and wherein the catalyst has a BET surface area of at least 5 m 2 /g.  
     
     
         9 . The composition of  claim 8  wherein M is a mixture of at least two rare earth elements selected from the group consisting of lanthanum, cerium, neodymium, praseodymium, dysprosium, samarium, yttrium, gadolinium, erbium, ytterbium, holmium, terbium, europium, thulium and lutetium.  
     
     
         10 . The composition of  claim 8 , with the proviso that the composition is substantially free of iron and copper.  
     
     
         11 . The composition of  claim 8  wherein the BET surface area of the composition is at least 30 m 2 /g.  
     
     
         12 . The composition of  claim 8  wherein the composition is prepared by a method comprising the following steps: 
 (a) preparing a solution of a chloride salt of the rare earth element or elements in a solvent comprising either water, an alcohol, or mixtures thereof;    (b) adding a nitrogen-containing base to cause the formation of a precipitate;    (c) collecting, drying and calcining the precipitate; and    (d) contacting the calcined precipitate with a chlorine source.    
     
     
         13 . The composition of  claim 12  wherein the chlorine source is gaseous, and is selected from the group consisting of HCl, Cl 2 , and mixtures thereof.  
     
     
         14 . A process for catalytically hydrodechlorinating a feed containing one or more of ethyl chloride, 1,2-dichloroethane and 1,1,2-trichloroethane comprising, contacting one or more of ethyl chloride, 1,2-dichloroethane, and/or 1,1,2-trichloroethane with a catalyst composition as defined in  claim 1  under process conditions sufficient to effect hydrodechlorination.  
     
     
         15 . A process for catalytically hydrodechlorinating a feed containing one or more of ethyl chloride, 1,2-dichloroethane and 1,1,2-trichloroethane comprising, contacting one or more of ethyl chloride, 1,2-dichloroethane, and/or 1,1,2-trichloroethane with the catalyst composition as defined in  claim 8  under process conditions sufficient to effect hydrodechlorination.