Elucidating synergistic effects during co-pyrolysis of plastics and paper in municipal solid waste: Thermal behavior and product characteristics

[Display omitted] •Thermal decomposition was promoted at 250–283 °C and suppressed above 400 °C.•Char yield increased mainly from melting suppressing aliphatic carbon release.•The impact of plastic melting on the co-pyrolysis process was further clarified by HTSM.•The gas yields were increased by 3.2 %–12.0 %, particularly H2, CH4, C2H4, and C2H6.•The underlying mechanism for the co-pyrolysis of plastics and paper was proposed. Plastics and paper are common components of municipal solid waste (MSW), making an in-depth understanding of their interactions essential for MSW thermal conversion. In this study, the co-pyrolysis behavior of plastic and paper was investigated. Firstly, the thermal decomposition characteristics were analyzed. Secondly, the pyrolytic behavior was elucidated in a fixed-bed reactor. Thirdly, the impact of plastic melting on co-pyrolysis was clarified. Results indicated that the thermal decomposition was accelerated between 250 °C and 283 °C, while temperatures above 400 °C resulted in inhibition. During fixed-bed pyrolysis, char yields (70.7–16.9 %) were increased by 4.0 %–12.7 %. This increase was mainly due to plastic melting, which contributed 8.6 % and increased aliphatic carbon content. Besides, PVC and PET exhibited a broader melting range > 500 °C. Bio-oil yields (25.5–70.6 %) were reduced by 3.4 %–12.4 %, primarily affecting aliphatic compositions. Gas yields (3.8–6.5 %) were reduced