Pyrolytic kinetics, reaction models and gas evolution of wood material with kerosene by TG-FTIR

The pyrolysis process of typical oils (kerosene, gasoline, etc) penetrating solid combustibles is one of the key behaviors of arsons and fire accidents caused by the leaking and spilling of these flammable oils on solid combustibles. Previous researches have mainly focused on the combustion characteristics of combustible solids infiltrated with flammable oils. However, there is a lack of comprehensive and systematic research on their pyrolysis characteristics, kinetics, and gaseous products. This study explored the pyrolytic behaviors, kinetics, reaction models and pyrolytic gases of pine wood with different contents (0, 5, 10, 20 and 30 wt%) of kerosene via thermogravimetry-Fourier transform infrared analysis (TG-FTIR). The results exhibit that the thermal decomposition processes of the pure pine wood and pine wood-kerosene mixture both show a three-stage process. The average activation energy of the mixture pyrolysis gradually decreases from 181.87 to 129.87 kJ/mol with the increase of kerosene content. The results further identify that the kinetic process of mixtures pyrolysis in the region 2 followed the three-dimensional diffusion model: g(α)= [1 − (1 − α)1/3]2. The principal finding of this study is that the obtained kinetic parameters of mixtures pyrolysis can precisely reproduce and predict conversion degree curves. Moreover, during the pyrolysis of the mixtures, the primary gaseous products identified include H2O, hydrocarbon, CO2, CO, carbonyl compounds, phenols, hydroxyl compounds. As the kerosene content increases, there is a significant rise in the production of hydrocarbons observed at the initial peak (around 420 K). Additionally, the predominant gaseous product observed at the peak temperature is carbonyl compounds. It is expected that this study can provide a practical guideline for the prediction of the fire size, the prevention and control of arson accidents and accident investigation.