Enhanced production of renewable aromatic hydrocarbons for jet-fuel from softwood biomass and plastic waste using hierarchical ZSM-5 modified with lignin-assisted re-assembly

Biomass-derived materials offer a huge potential as an alternative templating agent for tailoring new pore systems in zeolite to enhance its catalyst properties. Hierarchical ZSM-5 (H-type) was prepared in this study with the assistance of alkaline lignin in the re-assembly of alkali-treated parent material. The catalytic performance of the novel zeolite was tested in catalytic co-pyrolysis of softwood biomass and LDPE mixture, and the product distribution was optimized with varying reaction temperature (˚C) and plastic loading (g/g biomass). Results suggested that the enlarged pore openings in hierarchical ZSM-5 facilitated abundant reactive species, including the macromolecule oxygenates derived from lignin fraction in softwood, and deoxygenated products to pass through the catalyst layer. The higher selectivity of desirable aromatic hydrocarbons as well as coke formation inhibition were obtained at 450 ˚C compared to parent zeolite. Thus, the synergy of LDPE blending was intensified in hierarchical ZSM-5 through acid-catalyzed cracking and aromatization during catalytic upgrading.