Combustion characteristics of flue-cured tobacco and its kinetic analysis
In order to investigate the effects of combustion conditions on the thermal behavior of flue-cured tobacco, the thermal decomposition and combustion characteristics of flue-cured tobacco at different oxygen concentrations and heating rates were investigated with thermogravimetric analysis, and the kinetics at volatilization stage and char combustion stage were analyzed with Coats-Redfern method and Malek method. The results showed that: 1) The thermal decomposition process of flue-cured tobacco could be divided into dehydration, volatilization, char combustion and burnout stages. 2) The changes of combustion conditions significantly affected the thermal decomposition characteristics of flue-cured tobacco. 3) The combustion characteristic index of flue-cured tobacco increased with the increases of oxygen concentration and heating rate. 4) A3 model was used in the kinetic calculations at volatilization stage, while F1 model was used in the kinetic calculations at char combustion stage at different combustion conditions, and the relevant activation energies and exponential prefactors were obtained. The pyrolysis and combustion of flue-cured tobacco accelerated with the increase of oxygen concentration or heating rate.