Pyrolysis of waste pinewood sawdust using Py-GC-MS: effect of temperature and catalysts on the pyrolytic product composition

Abstract

Pyrolysis of waste pinewood sawdust (PWS) was investigated using Py-GC-MS to gauge its suitability for generating fuel and chemicals. The experiments were performed from 450–600 °C under purely thermal conditions and in the presence of 10 wt% HZSM-5, CuO and CaO, respectively. TGA revealed a three-stage degradation, with the second stage responsible for roughly 76.50 wt% of mass loss. Furthermore, the inherent inorganic elements in PWS, including Ca, K, Mn, Mg, Si, Fe, Co, Zn, Ba, Na, Sr, Ti, Pb, B, Cu, and Ni, were found to influence the pyrolysis product distribution. FTIR spectra confirmed characteristic C–O, C–H, CO and O–H bands arising from hemicellulose, cellulose and lignin. Py-GC-MS showed that HZSM-5, CuO, and CaO reduced phenol by 11.79%, 15.78%, and 13.03% respectively, and decreased acid fractions by 6.49%, 7.06%, and 7.33%, respectively. In contrast, these catalysts increased hydrocarbon yields by 5.0%, 6.15%, and 6.72% at 550 °C. The results demonstrated that catalyst selection, temperature control, and inherent mineral content collectively govern product yields, supporting thermo-catalytic pyrolysis as a sustainable route for PWS valorisation into higher-quality fuels. Furthermore, thermo-catalytic pyrolysis emerges as a promising,sustainable route for converting PWS into higher-quality fuel and satisfying the SDGs 7, 9, 12, and 13.