Recovery of Cerium and Zeolite from Spent Fluidized Catalytic Cracking Catalyst

Pretell V.; Ramos W.; Ubillas C.; Manrique H. · Proceedings of the LACCEI international Multi-conference for Engineering, Education and Technology (2024) · DOI: 10.18687/laccei2024.1.1.990

Resumen

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 o f 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. The solid extracted after acid leaching was mixed with powdered NaOH in a 1:1 ratio, and heated to 500°C for 1.5 hours, resulting in the formation of type 4A zeolite.

Instituciones: Universidad Nacional de Ingeniería