Recovery of Cerium and Zeolite from Spent Fluidized Catalytic Cracking Catalyst

Abstract

Fluidized Catalytic Cracking (FCC) catalysts are widely employed in the petrochemical industry and typically contain rare earth oxides (La2O3, Ce2O3) at concentrations ranging from 1 to 3.5 % w/w, depending on the producer and raw material being processed. It is estimated that over 400,000 tons of spent FCC catalyst (Ecat) are generated annually worldwide, primarily being disposed of in safety landfills. Consequently, Ecat represents a potential secondary source of lanthanides such as cerium. The characterization of Ecat from a local refinery was conducted, analyzing metal content by ICP-AES, thermogravimetric analysis, and FTIR spectroscopy. Subsequently, acid leaching with HCl, followed by caustic and thermal treatment of the residual solid post-leaching, was performed to obtain zeolite. Ecat characterization revealed a cerium content of 0.17 % w/w, and TGA analysis determined a thermal treatment temperature of 500 °C. Acid leaching resulted in a 58.44% w/w cerium recovery at a temperature of 70 °C, utilizing 4 M HCl, six hours of contact time, and an L/S ratio of 5 mL/g. Following caustic and thermal treatment of the solid residue post-acid leaching, a type 4A zeolite was successfully obtained.