An optimized heating source for heat-not-burn tobacco products through synergistic combustion of tobacco stalk and graphite carbon with K2CO3 catalyst

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 K₂CO₃ 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 K₂CO₃, 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 K₂CO₃ addition. Meanwhile, the burnout temperature can be reduced by 76–106 °C because the presence of K₂CO₃ 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.