Study on kinetics features of coal spontaneous combustion influenced by polyurethane

Abstract

In order to explore dangerous impacts of polyurethane on coal spontaneous combustionꎬ kinetic characteristics before and after introduction of polyurethane were studied through experiment and analyzed by using thermal analysis. Thenꎬ kinetic parameters were calculated with Flynn ̄Wall ̄Ozawa (FWO) and Starink models. Finallyꎬ mechanism function was determined by Bagchi method. The results show that with existence of polyurethaneꎬ reaction is accelerated and weight loss rate increases greatly in the initial stage (168-300 °C). Howeverꎬ the latter becomes relatively mild in subsequent stage of high temperature (465-714 °C) with value of activation energy being increased by about 6 kJ / mol compared with that before addition of polyurethane. And when reaction stopsꎬ final residual mass is approximately zeroꎬ and reaction is more complete than that of coal pyrolysis alone. Anthracite coal conforms to the randomly nucleating and nucleus growth model while mixture of coal and polyurethane is more inclined to first ̄order chemical reaction mechanism.