Recycling of Spent FCC Catalysts:  Conversion of Leached Residues to Zeolite ZSM-5

ChemSusChem. 2024 Mar 10:e202301642. doi: 10.1002/cssc.202301642. Online ahead of print.ABSTRACTThe commercial recycling of spent FCC catalyst typically focuses on recovering only 1 - 3% of rare-earth elements, with the remaining residues often disposed of in landfills. Here, we present a novel method to close a recycling loop for spent FCC catalyst. The method involves a series of leaching steps: Firstly, the spent catalyst material is leached with HNO3 to remove rare-earth elements such as La; second, solvothermal leaching with HCl removes most of Al and impurities like Fe, Ni and V; finally, a third leaching with H2SO4 removes Ti. The solid residues are then used to synthesize ZSM-5 without the addition of any extra silicon or aluminum sources after mild activation. The impurities in the synthesis gel strongly modify the properties of the zeolite, with ZSM-5 crystals containing higher levels of impurities exhibiting lower crystallinities, surface areas, acidities, cracking activities, as well as larger particle sizes.PMID:38462539 | DOI:10.1002/cssc.202301642

Source: ChemSusChem - March 10, 2024 Category: Chemistry Authors: Vladislav Timoshev Liane Andrea Haufe Oliver Busse Homa Hamedi Markus Seifert Jan J Weigand Source Type: research