Abstract
Waste tobacco stalk is blended with graphite carbon to form a composite carbon source, which is a promising external heating system for heat-not-burn tobaccos. In the current work, the effects of tobacco stalk amounts and the catalyst K(2)CO(3) on the co-combustion characteristics (i.e., the ignition temperature, burnout temperature, etc.) of graphite carbon were investigated. As a result, the ignition temperatures of the blend were determined by the tobacco straw, while the burnout temperature of the samples was reduced by approximately 60 °C due to the addition of a tobacco stalk. After the addition of K(2)CO(3), the ignition temperatures of the mixture were further decreased by 2-7 °C since the ignition temperature of the tobacco stalk was difficult to further reduce after K(2)CO(3) addition. Meanwhile, the burnout temperature can be reduced by 76-106 °C because the presence of K(2)CO(3) can significantly improve the combustion of graphite carbon. In addition, the kinetic analysis revealed that during the release of volatile matter, the oxidation process accords with the first-order kinetic model, while in the combustion process of mixed carbon source, the combustion process can be described by the third-order kinetic model.