A novel production of phase-divided jet-fuel-range hydrocarbons and phenol-enriched chemicals from catalytic co-pyrolysis of lignocellulosic biomass with low-density polyethylene over carbon catalysts

Abstract

The catalytic co-pyrolysis of Douglas fir and low-density polyethylene with commercial activated carbon catalysts was investigated for the first time. Six types of activated carbon catalysts were tested and compared. The obtained liquid product contained physically separated parts being in the oil and water phases, where the percentage of the oil phase ranged from 10.10 to 64.4 wt% depending on various co-pyrolysis conditions. The oil phase of bio-oil was rich in C₈–C₁₆ aromatics and aliphatics (up to 98.6 area%) that were compatible with transportation jet fuel. In addition, the main components of the bio-oil in the water phase were phenols and guaiacols, in which high phenol selectivity (up to 92.9 area%) and phenol concentration (up to 26.4 mg mL⁻¹) were achieved. Hydrogen, methane, carbon dioxide, and carbon monoxide were the main fractions of gaseous products, where a high concentration of methane (23.6 vol%) and carbon monoxide (39.1 vol%) could be obtained. The process was optimized based on an overall consideration of bio-oil yield, C₈–C₁₆ hydrocarbon selectivity, and phenol concentration. Furthermore, a reaction mechanism for the production of phenols and hydrocarbons was proposed. Our findings may provide a novel, green, and cost-effective route to produce phase-divided phenol-enriched chemicals and transportation jet fuels.