Synergistic effects on char and oil produced by the co-pyrolysis of pine wood, polyethylene and polyvinyl chloride

•Plastic-biomass interaction promoted biomass decomposition.•More oil and less char were produced from co-pyrolysis of pine wood and PE.•Less oil and more char were produced from co-pyrolysis of pine wood and PVC.•Plastic-biomass interaction improved quality of oil and chemical stability of char. The synergistic effects of the woody biomass (pine wood (PW)) and plastics (polyethylene (PE) and polyvinyl chloride (PVC)) during co-pyrolysis on the properties of char and oil were examined by thermogravimetric analysis (TGA) and fixed bed reactor. The results showed that PW-PE interaction increased the maximum weight loss rate of PW by 8.0–23.7%. Co-pyrolysis of PW-PE blends produced lower quantity of char (13.8–22.4%) and higher quantity of oil (3.7–4.4%) as compared to the theoretical results. PW-PVC interaction decreased the temperature corresponding to the maximum weight loss rate of PW by 47–51 °C. Co-pyrolysis of PW-PVC blends yielded more char (15.5–27.9%) and less oil (7.2–14.4%) than expected values. Also, the interaction of biomass and plastic materials decreased the H/C atomic ratio of char, which resulted in a higher chemical stability of char. The fuel quality of oil produced from mixtures was improved due to a lower O/C atomic ratio of oil as compared to the theoretical results.