UN PROCEDIMIENTO PARA ELIMINAR COMPONENTES COMBUSTIBLES DE UN GAS

摘要

Combustible components in waste gases obtained by the combustion of a fuel, are eliminated by mixing with an oxygen-containing gas and passing over a catalyst which consists of a refractory inorganic oxide support comprising at least a major proportion of alumina having an apparent bulk density of less than 0.4 grams per c.c., the support constituting the major component by weight of the catalyst and carrying a metal of the platinum group in an amount of from 0.05 to 2% by weight together with at least one other component selected from the platinum group metals and the oxides of iron, nickel, cobalt, copper, vanadium, molybdenum, tungsten, calcium, strontium and barium. The reaction temperature is from 95 DEG to 1095 DEG C. The refractory inorganic oxide may be pure alumina or alumina with 0.5 to 10% by weight of silica. The metal oxides may be present in amounts of from 1.0 to 10.0% by weight. The combustible components include hydrocarbons, partially oxidized hydrocarbons, and carbon monoxide. Numerous examples of catalysts are given. Specification 693,648 is referred to.ALSO:A catalyst, for use in eliminating combustible components from a gas, consists of, as major component, a refractory inorganic oxide comprising at least a major proportion of alumina having an apparent bulk density of 0,4 grams per c.c. which supports a metal of the platinum group, present in amounts of 0,05-2,0% by weight together with at least one other component selected from the platinum group metals, and the oxides of iron, nickel, cobalt, copper, vanadium, molybdenum, tungsten, calcium, strontium and barium. The refractory inorganic oxide may be pure alumina or alumina with 0,5-10% by weight of silica, and preferably has an apparent bulk density of 0,15-0,35 grams per c.c. The metal oxides may be present in amounts of from 1,0 to 10,0% by weight of the catalyst. The catalyst is prepared by impregnating alumina spheres with a solution containing salts of the metals to be used and then calcining the impregnated spheres to thermally decompose the salts to the metals and/or oxides. A halogen, e.g. chlorine or fluorine, may also be incorporated in the catalyst by impregnation by e.g. the ammonium salt. Numerous examples of catalysts are given. Specification 693,648 is referred to.