Co-pyrolysis of wood waste with leather, polyurethane foam, and textile waste: Differential effects on product yields and composition

End-of-life furniture waste is a rapidly growing and heterogeneous fraction of municipal solid waste (MSW) that is difficult to recycle. This study investigates the co-pyrolysis of pine sawdust with three representative furniture waste residues, synthetic leather, polyurethane foam (PU foam), and textile (cloth), as a resource-oriented treatment pathway for bulky MSW. Experiments were conducted at 550°C with a fixed 10 wt% residue addition, and the bio-oil, biochar, particulate matter (PM), and gas products were characterized using gas chromatography-mass spectrometry, scanning electron microscopy-energy dispersive X-ray spectroscopy, Brunauer–Emmett–Teller (BET), Fourier-transform infrared spectroscopy, Raman spectroscopy, and Pearson correlation analysis. The three residues exerted distinct regulatory effects on product distribution. Textile addition raised the bio-oil yield from 47.4 to 55.8 wt% while cutting PM to 1.32 wt%. PU foam promoted aromatic hydrocarbons and increased bio-oil phenolics from 8.56 to 20.66%, and textile increased phenolics to 21.76%. Synthetic leather favored gas and char production, raising the gas yield to 41.15 wt% and, through the catalytic action of inorganic fillers, the char specific surface area from 299 to 402 m ² g ⁻¹ . Chlorine-containing organic compounds were not detected in the co-pyrolysis bio-oils, indicating effective in situ retention of chlorine in the solid phase and reduced environmental risk compared with incineration. Pearson correlation analysis quantified and ranked the contribution of each residue to product yields and composition, providing a basis for mixed-waste feedstock design. Overall, co-pyrolysis enables the direct valorization of complex furniture waste streams, offering a cleaner and more flexible alternative to conventional disposal and supporting the transition of MSW management toward circular resource recovery.