ABSTRACT:Polyvinyl chloride (PVC) and lignocellulosic biomasses are typical solid wastes. Synergistic effect chlorine and inorganic removal were investigated during the co-hydrothermal carbonization (co-HTC) at 260 °C for 30 min. The solid products were characterized by Fourier Transform Infrared Spectrometer and Scanning Electron Microscope. It is found that the mass yield, dichlorination, and removal of inorganics demonstrated synergistic effects in the co-HTC process. The dechlorination efficiency (DE) of bamboo green (BG), wheat straw (WS), corn stalk (CS), and corn cob (CC) with PVC was in the range of 70.46-87.01%, which was higher than the predicted value of 67.14-72.56%. During the co-HTC process, the lignocellulosic biomass fragments wrapped on the surface of the molten PVC suppress polymerization, and the hydroxyl functional groups on the surface of the lignocellulosic biomass promote the substitution reaction with the C-Cl bond in PVC. The amount of insoluble lignin in various lignocellulose biomasses influence whether or not there is a beneficial synergistic effect of dechlorination between lignocellulose and PVC. Meanwhile, during the co-HTC process, the removal efficiency (RE) of inorganics was greatly improved and demonstrated a beneficial synergistic effect. The increase in RE of inorganics is primarily due to the release of HCl from PVC, which accelerates biomass degradation and enhances the acidity of the reaction system. Overall, these findings have the potential to provide more comprehensive theoretical guidance for the conversion of difficult-to-treat waste into clean and sustainable energy.