US 4,542,116 A · Catalyst for removing sulfur oxides from a gas

Abstract

Sulfur oxides are removed from a gas by an absorbent comprising at least one inorganic oxide selected from the group consisting of the oxides of aluminum, magnesium, zinc, titanium, and calcium in association with yttrium or yttrium combined with at least one free or combined rare earth metal selected from the group consisting of lanthanum, cerium, praseodymium, samarium, and dysprosium, wherein the ratio by weight of inorganic oxide or oxides to yttrium or yttrium combined with a rare earth metal or metals is from about 0.1 to about 30,000. Absorbed sulfur oxides are recovered as a sulfur-containing gas by contacting the spent absorbent with a hydrocarbon in the presence of a hydrocarbon cracking catalyst at a temperture from about 375.degree. to about 900.degree. C. The absorbent can be circulated through a fluidized catalytic cracking process together with the hydrocarbon cracking catalyst to reduce sulfur oxide emissions from the regeneration zone thereof.

Claims15

Dependent claims

A composition of matter prepared by the steps comprising:

(a) impregnating a particulate solid cracking catalyst comprising from about 0.5 to about 50 weight percent of a crystalline aluminosilicate zeolite distributed throughout a matrix consisting essentially of from about 40 to about 100 weight percent of alumina and from about 0 to about 60 weight percent of silica with an oxide of yttrium wherein the amount of said oxide of yttrium is sufficient to add from about 0.004 to about 10 weight percent of yttrium, calculated as the oxide of yttrium, to said catalyst particles;
and
(b) calcining said impregnated catalyst particles at a temperature between about 200.degree. and about 820.degree. C.

Dependencies are inferred from the claim text.

Catalyst for removing sulfur oxides from a gas

Life of this patent

Catalyst for removing sulfur oxides from a gas

Life of this patent

Abstract

Claims15