Catalytic fast co-pyrolysis of bamboo sawdust and waste plastics for enhanced aromatic hydrocarbons production using synthesized CeO2/γ-Al2O3 and HZSM-5

Abstract

Fast co-pyrolysis of bamboo sawdust and waste plastic (linear low-density polyethylene, LLDPE) over a dual catalytic stage of synthesized CeO2/γ-Al2O3 and HZSM-5 was conducted to enhance aromatic hydrocarbons production. Experimental results indicated that the catalyst to biomass (C/B) mass ratio played a determining role in the formation of hydrocarbon intermediates and a C/B mass ratio of 4 facilitated the production of aromatic hydrocarbons. Dual catalytic fast co-pyrolysis of bamboo sawdust and LLDPE using synthesized CeO2/γ-Al2O3 and HZSM-5 increased the concentration of aromatic hydrocarbons and a CeO2/γ-Al2O3 to HZSM-5 mass ratio of 1:3 maximized the target products. The content of aromatic hydrocarbons was increased at first and then decreased as the LLDPE percentage was elevated from 20% to 100% during the dual catalytic fast co-pyrolysis process, with the highest concentration obtained at 75% LLDPE percentage. In addition, the additive effect of monocyclic aromatic hydrocarbons was enhanced with the increasing of LLDPE percentage in the feedstock blends, and higher LLDPE proportion favored the production of xylenes, ethylbenzene, and alkylbenzenes as the additive effects were significantly promoted.