白肋烟热解特性及其动力学

采用TG-DTG-DSC热分析联用技术研究了不同产地白肋烟的热解燃烧行为及其动力学，结果表明，从室温加热到800℃，不同产地的白肋烟热解燃烧过程均经历4个热失重过程，但温度范围不同，且每个阶段的质量和热量变化均不同，样品的主要反应发生在138~583℃内. 采用Coats-Redfern法对不同产地的白肋烟样品4个热失重阶段进行了动力学计算，结果表明，第I与第II阶段机理函数相同，而第III与第IV阶段机理函数相同；燃尽阶段的活化能明显比其他阶段的活化能高. 采用特殊收集装置收集4个热失重阶段的粒相产物，对其有害产物和致香成分的定量分析结果表明，不同产地的白肋烟样品在热解不同阶段产生的有害物质和致香成分的量有所不同，但大部分有害物质和致香成分在第II热失重阶段产生，且产生的量相对较大.

Thermal Decomposition Characteristics and Kinetics of Burley Tobacco

The thermal decomposition processes and combustion characteristics of burley tobacco samples from different habitats were studied by TG-DTG-DSC thermal analysis technique. Their thermal kinetics was also investigated. The results show that the thermal decomposition process of burley tobacco has four weight loss stages from room temperature to 800℃. The temperature range of four weight loss stages is different for different samples, and the mass change and heat release in different stages are different. The major reactions of burley tobacco occur in 138~583℃, that is volatilization and combustion stage, and coking combustion stage. The kinetic parameters in the four stages of burley tobacco from different habitats were calculated by Coats-Redfern method, and the reasonable mechanism function was selected by the Malek method. The results show that the first and second weight loss stages have the same mechanism function, the same to the third and fourth weight loss stages. The activation energy of burnout stage is higher than other stages in the four stages. The products in the four stages were collected by special collection device and the harmful products and aroma compositions analyzed. The results show that the quantities of harmful substances and aroma components are different in different weight loss stages for different burley tobacco samples in different growing areas, but most of harmful substances and aroma components are produced in the second weight loss stage, and the quantity of products is bigger than other weight loss stages.