Process for removing sulfur oxides from a gas

摘要

Sulfur oxides are removed from a gas by an absorbent which comprises a physical mixture of (1) a particulate cracking catalyst comprising from about 0.5 to about 50 weight percent of a crystalline aluminosilicate zeolite which is distributed throughout a porous matrix wherein said matrix comprises from about 70 to about 100 weight percent of alumina and (2) a particulate solid other than cracking catalyst which comprises at least one inorganic oxide selected from the group consisting of the oxides of aluminum and magnesium in association with at least one free or combined rate 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 rare earth metal or metals is from about 1.0 to about 1,000. Absorbed sulfur oxides are recovered as a sulfur-containing gas comprising hydrogen sulfide by contacting the spent absorbent with a hydrocarbon at a temperature from about 375 DEG to about 900 DEG C. The absorbent can be circulated through a catalytic cracking process to reduce sulfur oxide emissions from the regeneration zone.