Effect of potassium organic and inorganic salts on thermal decomposition of reconstituted tobacco sheet

Abstract

In order to deeply investigate the role of potassium in modifying thermal behavior and burning characteristics of reconstituted tobacco sheet (RTS), electrodialysis (ED) technology was employed at first to remove the main ions in the tobacco extract to reduce interference of endogenous ions. Characterization on thermal behavior of RTS treated with three organic (acetate, malate and citrate) potassium salts and three inorganic (chloride, sulfate and phosphate) potassium salts was then performed using thermogravimetric analyzer coupled with Fourier transforms infrared spectrometer (TG-FTIR) at the heating rate of 20 °C min−1. TG results illustrated that potassium decreased the peak temperature of carbohydrate pyrolysis, retarded the thermal degradation of the major components of RTS and meanwhile promoted the formation of stable char firmly depending on its chemical state. The organic potassium salts had a more significant effect on the process of char oxidation than inorganic ones with a new peak at around 570 °C. Analyses of evolved gaseous products distribution demonstrated a significant reduction of CO and CO2 during carbohydrates pyrolysis in the presence of potassium, especially organic potassium salts. Moreover, the maximum firecone temperature was also measured by Infrared thermography, and it had been found that the burning cone temperature of ED-modified RTS was averagely 13.27 °C higher than that of organic potassium treated RTS but averagely 16.57 °C lower than that of inorganic ones.