Catalyst and process for catalytically cracking a sulfur-containing hydrocarbon feed with reduced sulfur oxides emission during catalyst regeneration

摘要

A catalyst suitable for use in catalytic cracking comprises a mixture of different types of particles of which one type (type A) is present in a major concentration and another type (type B) is present in a minor concentration. The type A particles comprise one or more Group VIII noble metals (preferably platinum) composited with a support comprised of a crystalline aluminosilicate component distributed in an active cracking matrix, suitably a matrix of silica-alumina. The type B particles comprise at least one Group IIA metal (preferably magnesium) composited with a support (suitably silica-magnesia or silica-magnesium) which may also contain a dispersed crystalline aluminosilicate zeolite component.;When used in a process for the continuous catalytic cracking of a sulfur-containing hydrocarbon feed, the regeneration of the spent catalyst causes at least some of the sulfur in the coke deposited on the catalyst to be fixed as the sulfate in the regenerated catalyst, thereby reducing the sulfur oxides content of the regenerator flue gas, and sulfate in the regenerated catalyst is reduced to liberate H₂S on transfer to the hydrocarbon cracking zone.