Upgrading of bio-oil from catalytic co-pyrolysis of PVC and biomass over Ni-modified ZSM-5

The co-pyrolysis of PVC- and biomass-upgraded bio-oil catalyzed by Ni-modified ZSM-5 was studied. Ni-ZSM-5 catalyst was prepared by impregnation method and characterized by XRD and NH3-TPD. The co-pyrolysis characteristics of polyvinyl chloride (PVC) and wood powder (WP) were studied by TGA, and the effect of molecular sieves on the pyrolysis characteristics was also investigated. The pyrolysis experiments were carried out by a fixed-bed reactor, the composition and content of bio-oil and gas were analyzed, and the number of carbon atoms in the bio-oil was classified. The addition of H-ZSM-5 catalyst resulted in a significant increase in the content of light aromatic hydrocarbons compared with no catalyst, while the use of modified Ni-ZSM-5 further promoted the generation of light aromatic hydrocarbons and inhibited the formation of heavy aromatic hydrocarbons, which can be attributed to the unique pore structure of molecular sieve and the excellent catalytic activity of Ni. The formation mechanism of monocyclic aromatic hydrocarbons was inferred.