Sustainable valorization of real polyurethane mattress waste via a novel multistage thermochemical approach

Abstract

This study explores pyrolysis as a sustainable route for the treatment and valorization of polyurethane-based mattress waste, a major contributor to urban landfill accumulation. It delivers a comprehensive assessment of the composition and properties of the products generated. The gaseous fraction, investigated through an in situ TGA/FTIR-MS scheme and GC, was found to be rich in methane, ammonia, hydrogen, and carbon dioxide, highlighting opportunities for both chemical synthesis and energy production, particularly via syngas generation. The liquid fraction, characterized by GC-MS and FTIR, contained a wide distribution of oxygenated compounds, aromatics, and hydrocarbons; simulated distillation further revealed its strong potential for applications in oil refining and chemical manufacturing. Detailed analysis of the solid fraction (XRD, XPS, N 2 physisorption, and elemental analysis) showed a carbon-rich material with promising applications as an adsorbent or solid fuel. Importantly, this fraction, together with the liquid product, was successfully employed as feedstock to prepare cobalt-based catalysts for a second step by a mechanochemical approach, which allows the production of a gas stream with competitive performance compared to reference catalysts prepared with commercial carbons.