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

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

Abstract

The 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.

Details

OriginalspracheEnglisch
Aufsatznummere202301642
FachzeitschriftChemSusChem
Jahrgang17
Ausgabenummer14
PublikationsstatusAngenommen/Im Druck - 2024
Peer-Review-StatusJa

Schlagworte

Schlagwörter

  • Heterogeneous catalysis, MFI, Recycling, Spent FCC catalyst, Zeolites