Ultra high temperature shift catalyst with low methanation
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, wherein the support further comprises up to about 40%, by weight, of a transitional alumina, 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 one or more metal oxides selected from the group consisting of the following: zirconia, ceria, lanthana, praseodymium oxide, neodymium oxide, yttria, titania, silica, samarium oxide, tungsten oxide, molybdenum oxide, calcia, chromia, magnesia, baria, strontium oxide, and mixtures thereof.
3. The water gas shift catalyst of claim 2 , wherein the high surface area material comprises ceria and zirconia.
4. The water gas shift catalyst of claim 3 wherein the support further comprises praseodymium oxide and/or neodymium oxide.
5. 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 oxides selected from cerium, zirconium, lanthanum, yttrium, praseodymium, neodymium, samarium, tungsten, barium, strontium and molybdenum and mixtures thereof.
6. The water gas shift catalyst of claim 1 , wherein the high surface area material is selected from the group consisting of high surface area ceria, titania, silica, zirconia, and mixtures thereof.
7. The water gas shift catalyst of claim 1 , wherein the catalyst does not include platinum, palladium, rhodium or ruthenium.
8. The water gas shift catalyst of claim 1 , wherein rhenium comprises from about 0.05 to about 1, of the catalyst, by weight.
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 the transitional alumina comprises gamma alumina.
13. 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.
14. 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, wherein the support further comprises up to about 40%, by weight, of a transitional alumina, 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.
15. The catalyst of claim 14 , wherein the mixed metal oxides further comprise praseodymium oxide and/or neodymium oxide.
16. The water gas shift catalyst of claim 14 further comprising an alkali or alkaline earth metal dopant.
17. The catalyst of claim 14 wherein the transitional alumina comprises gamma alumina.
18. 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 one or more metal oxides, up to 40%, by weight, gamma alumina and an alkali or alkaline earth metal dopant, 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.
19. 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 a 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 up to 40%, by weight, of a transitional alumina, 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.
20. The process of claim 19 wherein the quantity of carbon monoxide is between about 1 and 15% and the molar steam to dry gas ratio is from about 0.1 to about 5.