Deactivation and regeneration of solid acid and base catalyst bodies used in cascade for bio-oil synthesis and upgrading

The modes of deactivation -and the extent to which their properties can be restored- two catalyst bodies used in cascade for bio-oil synthesis have been studied. These catalysts include a solid acid granulate (namely ZrO2/desilicated zeolite ZSM-5/attapulgite clay) employed ex-situ catalytic fast pyrolysis biomass, and base extrudate (K-exchanged USY/attapulgite subsequent upgrading. Post-mortem analyses both with Raman spectroscopy confocal fluorescence microscopy revealed presence highly poly-aromatic coke distributed an egg-shell manner. Deactivation due adsorption onto sites affected ZSM-5-based catalyst, while it is structural integrity loss, resulting from KOH-mediated framework collapse, main deactivating factor. A hydrothermal regeneration process reversed detrimental effects largely recovering acidity (?80%) textural (?90%), but worsened damage suffered by catalyst.