Ultra high temperature shift catalyst with low methanation

Abstract

A water gas shift catalyst for use at temperatures above about 450° C. up to about 900° C. or so comprising rhenium deposited on a support, preferably without a precious metal, wherein the support is prepared from a high surface area material, such as a mixed metal oxide, particularly a mixture of zirconia and ceria, to which may be added one or more of a high surface area transitional alumina, an alkali or alkaline earth metal dopant and/or an additional dopant selected from Ga, Nd, Pr, W, Ge, Fe, oxides thereof and mixtures thereof.

1 . A water gas shift catalyst for use at temperatures above about 450° C. up to about 900° C. comprising rhenium deposited on a support, wherein the support comprises a high surface area material with a surface area from about 30 m 2 /g to about 200 m 2 /g, and wherein the catalyst does not include a precious metal selected from the group consisting of platinum, palladium, rhodium, ruthenium, iridium, osmium, silver, gold and mixtures thereof. 
     
     
         2 . The water gas shift catalyst of  claim 1 , wherein the high surface area material comprises two or more metal oxides selected from the group consisting of oxides of cerium, zirconium, lanthanum, yttrium, praseodymium, neodymium, samarium, tungsten, barium, strontium and molybdenum and mixtures thereof. 
     
     
         3 . The water gas shift catalyst of  claim 1 , wherein the high surface area material comprises a mixed metal oxide comprising two or more metal oxides selected from the group consisting of zirconia, ceria, praseodymia and neodymia. 
     
     
         4 . The water gas shift catalyst of  claim 1 , wherein the high surface area material comprises a transitional phase, high surface area promoted alumina, wherein the alumina is promoted with an oxide selected from oxides of cerium, zirconium, lanthanum, yttrium, praseodymium, neodymium, samarium, tungsten, barium, strontium and molybdenum and mixtures thereof. 
     
     
         5 . The water gas shift catalyst of  claim 1 , wherein the catalyst does not include platinum, palladium, rhodium or ruthenium. 
     
     
         6 . The water gas shift catalyst of  claim 1 , wherein rhenium comprises from about 0.05 to about 10% of the catalyst, by weight. 
     
     
         7 . The water gas shift catalyst of  claim 1 , wherein the high surface area material comprises ceria and zirconia. 
     
     
         8 . The water gas shift catalyst of  claim 7 , wherein the support further comprises praseodymium oxide or neodymium oxide. 
     
     
         9 . The water gas shift catalyst of  claim 1  further comprising an alkali or alkaline earth metal dopant. 
     
     
         10 . The water gas shift catalyst of  claim 9 , wherein the dopant is selected from the group of consisting of sodium, potassium, cesium, and rubidium oxides and mixtures thereof. 
     
     
         11 . The water gas shift catalyst of  claim 9 , wherein the alkali or alkaline earth dopant comprises from about 0.1 to about 10% of the catalyst, by weight. 
     
     
         12 . The water gas shift catalyst of  claim 1 , wherein a dopant is added to the catalyst selected from the group consisting of Ga, Nd, Pr, W, Ge and Fe, their oxides and mixtures thereof. 
     
     
         13 . A water gas shift catalyst for use at temperatures above about 450° C. up to about 900° C. comprising rhenium deposited on a support, wherein the support comprises a mixture of metal oxides comprising zirconia and ceria, and wherein the catalyst does not include any precious metal from the group consisting of platinum, palladium, rhodium, ruthenium, iridium, osmium, silver, gold and mixtures thereof. 
     
     
         14 . The catalyst of  claim 13 , wherein the mixed metal oxides further comprise praseodymium oxide or neodymium oxide. 
     
     
         15 . The water gas shift catalyst of  claim 13  further comprising an alkali or alkaline earth metal dopant. 
     
     
         16 . A water gas shift catalyst for use at temperatures above about 450° C. up to about 900° C. comprising rhenium on a support, wherein the support comprises two or more metal oxides selected from ceria, zirconia, praseodymia and neodymia, and an alkali or alkaline earth metal dopant, wherein the catalyst does not include any precious metal from the group consisting of platinum, palladium, rhodium, ruthenium, iridium, osmium, silver, gold and mixtures thereof. 
     
     
         17 . A water gas shift process for use at temperatures above about 450° C. up to about 900° C. comprising preparing a feed stream containing carbon monoxide and steam and passing that feed stream over a water gas shift catalyst comprising rhenium deposited on a support, wherein the support comprises a high surface area material with surface area from about 30 m 2 /g to about 200 m 2 /g at a pressure above about 50 psi, (3.4 bar), wherein the support comprises ceria and zirconia, and wherein the catalyst does not include any precious metal from the group consisting of platinum, palladium, rhodium, ruthenium, iridium, osmium, silver, gold and mixtures thereof. 
     
     
         18 . The process of  claim 17  wherein the quantity of carbon monoxide in the feed stream is between about 1 and 15% and a molar steam to dry gas ratio in the feed stream is from about 0.1 to about 5. 
     
     
         19 . The process of  claim 17 , wherein the support further comprises praseodymium oxide or neodymium oxide. 
     
     
         20 . The process of  claim 17 , wherein the catalyst further comprises an alkali or alkaline earth metal dopant.