Online evaluation of catalytic co-pyrolysis of hemicellulose and polypropylene over CaO catalyst

The co-utilization of hydrogen-rich plastic and biomass can upgrade bio-oil. This process was further developed by adding catalysts to the co-pyrolysis of biomass and plastic. In this work, thermal and catalytic co-pyrolysis of hemicellulose and polypropylene (PP) was investigated by TG combined with mass spectrometry, which is characterized by in-situ online detection for pyrolysis products. The intrinsic interaction as well as the reaction mechanism were revealed for the catalytic co-pyrolysis. The results show that CaO catalyst can enhance xylan decomposition and increase the production of small alkene from PP. The formation of olefins and furan compounds can be promoted significantly by CaO catalyst. Besides hydrocarbon pool mechanism, Diels-Alder reaction further contributes to additional aromatics formation. This work provides detailed reaction information, which can help to further understand the mechanism of catalytic co-pyrolysis of biomass and plastic.