Thermal Decomposition of Tobacco: V. Influence of Temperature on the Formation of Carbon Monoxide and Carbon Dioxide

The temperature-yield profiles of CO and CO₂ have been obtained by the analysis of the effluent gas from the differential thermaI analysis (DTA) and pyrolysis gas chromatography (PGC) of tobacco. The CO profiles obtained from DTA show that CO is continuously generated from 140° to 950°C and has four temperatures for maximum formation: 240°, 310°, 450° and 690°C. These maxima correspond to those exhibited by the effluent gas detection (EGD) curve. AIl data show that the major portion of CO is formed above 650°C, even though the weight loss of tobacco at these temperatures is less than 10 %. The CO₂ profile obtained from thermal analysis also corresponds to effluent gas detection curve and shows that the majority of CO₂ is formed below 500°C. The profiles for CO₂ from PGC indicate that the reduction of CO₂ by carbon to form CO at temperatures above 600°C are not significant under these pyrolysis conditions. Analysis of the gas phase from the thermal analysis of extracted tobaccos shows that this method is a means for studying the influence of product modification on the formation of CO and CO₂ especially at lower temperatures. The PGC of these modified tobaccos appears to be of little value for studying the effect of product modification on the formation of CO and CO₂