Catalytic co-pyrolysis of woody biomass with polypropylene: Effects of Korean loess hybrid catalysts and pyrolysis temperatures

This paper describes an effort to improve the catalytic characteristics of Korean loess (KL) for the co-pyrolysis of biomass and polypropylene, resulting in a unique multifunctional catalyst. Korean loess was physically and chemically transformed into a microporous structure (ZSM) fitting for co-pyrolysis. Using the catalysts manufactured above, analytical co-pyrolysis was carried out using a Py-GC/MS system with pinewood sawdust and polypropylene mixed at a ratio of 1:1 (w/w). To investigate the impacts of the use of catalysts and the pyrolysis temperatures on the distribution of volatile pyrolytic products, the experiments were designed to mix 2- or 8-fold catalyst mass quantities with feedstock and pyrolyze at temperatures of 500 degrees C, 600 degrees C, and 700 degrees C. Compared to pure Korean loess, the catalytic activity of the optimal hybrid catalyst (0.2KL/ZSM) favored decarbonylation over dehydration, making it more effective than mesoporous ZSM. Pyrolytic products generated using the hybrid catalyst (0.2KL/ZSM) had a higher hydrogen concentration (9.8 wt%) than pyrolytic products produced using ZSM catalysts (6.5 wt%). Because of this, the pyrolytic products were expected to be more compatible as a fuel over 0.2KL/ZSM, with an HHV of 27.4 MJ/kg as opposed to 26.5 MJ/kg over ZSM. Zeolite framework catalysts could promote the production of aromatic chemicals (3.0 mg/g for non-catalyst, 34.7 mg/g for KL, and 53.9 mg/ g for 0.2KL/ZSM) in the co-pyrolysis of PP with pine, which synergistically enhance oligomerization, cyclization, and aromatization reactions at catalyst acid sites. Concerning aromatic hydrocarbon yields, 0.2KL/ZSM could be expected to perform very similarly to ZSM in producing 74.7 mg/g of MAH+PAH at 600 degrees C.