Effect of ethanolysis on the structure evolution, pyrolysis kinetics, and volatile products of waste poplar sawdust

Ethanolysis had been the promising approach for the deoxygenation of waste poplar sawdust (WPS), and its effect of structure variation and pyrolysis behaviors on the WPS was investigated in present research. The decreasing of C–O chemical bonds and the increasing of C content was typical phenomenon during the ethanolysis of WPS. The pyrolysis behaviors of sample were performed by thermogravimetric analyzer at three different heating rates. The pyrolysis kinetics and thermodynamics of WPS, residue230 (R230), and residue260 (R260) were well determined on the basic of three model-free iso-conversional methods. Average activation energy derived from the Kissinger-Akahira-Sunose (KAS) method of R260 displayed the high value (445.06 kJ/mol), followed by 224.88 kJ/mol for R230, then 200.68 kJ/mol for WPS. Thermodynamics data suggested that R260 required more total energy consumption for the breakage of chemical bonds. Additionally, pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) results showed that the highest relative content of volatile products compound derived from the flash pyrolysis of R230 and R260 was 47.12 % (d-Allose) and 38.69 % (Phenols), respectively, and RC value of arenes significantly increased to 15.82 % after ethanolysis. The findings would significantly contribute to the valuable utilization of waste biomass and its residues.