Abstract: The present invention describes a process to obtain zeolites more resistant to calcination in the presence of water vapor at high temperatures, which is a characteristic condition found during the catalyst regeneration in the Fluid Catalytic Cracking (FCC). One apply the invention to high silica-alumina ratio (SAR) zeolites, for instance the ZSM-5 zeolite, which are able to crack only short hydrocarbon molecules, with normal or slightly branched carbon chain, and which are also able to increase considerably the yields of olefins and LPG. Through the combination of mild pre-calcination and phosphorous deposition one obtain a zeolite which presents higher catalytic activity than zeolites non treated or treated through other processes of the state-of-technique.

Abstract: A multifunctional additive for maximizing yield of light olefins and LPG, with a tolerance to contaminant metals. Maximization of the referenced properties is accomplished through the use of a zeolite treated with a phosphorus source, calcined and impregnated with a rare earth salt. The process for preparation of the referenced catalyst includes the following steps: preparation of a precursor containing a zeolite that is selective of olefins with a source of phosphorus; placement of a source of phosphorus in this precursor through calcination; deposition of rare earth salts on the surface of the additive for maximizing the yield of light olefins and LPG that forms; and drying the multifunctional additive formed.