Patent ID: 6066308
Filing Date: 2000-05-23
Classification: B01D,B01J,C01F,C01P,Y02T

Abstract:
In a process for the treatment of exhaust gases of an internal combustion engine, for the hydrogen treatment of petroleum products, for the recovery of sulfur from sulfur compounds, for dehydration, reforming, steam reforming, dehydrohalogenation, hydrocracking, hydrogenation, dehydrogenation or dehydrocyclization of hydrocarbons or other organic compounds, and for oxidation and reduction reactions, wherein alumina agglomerates are employed as a catalyst support in said process, the improvement which comprises, obtaining said alumina agglomerates by(i) preparing a ground or unground powder of active alumina having a poorly crystalline structure, an amorphous structure or an admixture of said structures;(ii) agglomerating said active alumina powder to form alumina agglomerates;(iii) combining (a) at least one acid selected from the group consisting of nitric acid, hydrochloric acid, perchloric acid, and sulfuric acid, and (b) at least one compound providing an anion capable of combining with aluminum ions in solution selected from the group consisting of nitrate, chloride, sulfate, perchlorate, bromoacetate and dibromoacetate salts and salts of monocarboxylic acids to form an aqueous treatment medium, wherein the concentration of the acid in the aqueous medium is less than 20% by weight and the concentration of the anion donor compound is less than 50% by weight and wherein the quantity of the acid is in an amount effective to dissolve from 0.5% to about 15% by weight of the alumina agglomerates, and subjecting said agglomerates to an aqueous medium treatment by contacting said agglomerates with said aqueous treatment medium;(iv) subjecting the combined agglomerates and the aqueous treatment medium to a hydrothermal treatment by heating at a temperature in the range of from about 80.degree. C. to about 250.degree. C., wherein the combination of said aqueous medium treatment and hydrothermal treatment increases the porosity of the agglomerates by expansion; and then(v) thermally activating the agglomerates at a temperature in the range of from about 500.degree. C. to about 1100.degree. C., with essentially no loss of alumina agglomerates treated as a result of the combination of steps (iii)-(v).