烟叶原料种类对烟草颗粒热解和释烟特性的影响

为揭示颗粒型加热卷烟烟芯材料热解与烟气释放规律，采用湿法造粒技术，利用热重-红外联用装置（TG-FTIR）与锥型量热仪（CONE），探究了烟叶原料种类对其热解与释烟特性的影响规律。结果表明:①不同种类烟叶原料制备的烟草颗粒失重过程基本一致，相较于烤烟颗粒而言，梗丝、再造烟叶、白肋烟、雪茄烟和香料烟制备的烟草颗粒最大失重速率温度向低温区偏移，且梗丝颗粒和再造烟叶颗粒易挥发性物质释放阶段的失重速率较大，该阶段烤烟颗粒具有最大失重比例，且热解完成后固体残余量最小。②红外光谱结果显示，不同烟叶原料制备的烟草颗粒气相产物释放过程基本一致，因化学成分的差异使得释放温区范围略有差异。其中碳水化合物、酚类和醇类等含羟基化合物的释放温区主要集中在150~300 ℃之间；含C=O的羰基、酯类等化合物以及CO释放过程分为两个阶段，分别为250~400 ℃和500 ℃左右；当温度超过500 ℃时，烟草颗粒热解释放出NH₃和CH₄。③梗丝、再造烟叶以及雪茄烟制备的烟草颗粒的堆积密度约在0.54~0.56 g/cm3之间，相较其他原料而言较小，但烟气释放速率较大，累积释烟总量较高，其中，梗丝颗粒起始释烟速率最大；CO与CO₂释放的整体变化趋势与释烟速率曲线变化规律一致，即释烟速率越大，CO与CO₂的释放速率越大。 

Effects of tobacco types on pyrolysis and smoke release of tobacco granules

To reveal the characteristics of pyrolysis and smoke release from tobacco section of heated tobacco products, tobacco granules were prepared via wet granulation. The effects of tobacco types on pyrolysis and smoke release of the tobacco granules were studied with thermogravimetric-Fourier transform infrared (TG-FTIR) and cone calorimeter (CONE). The results showed that: 1) The weight loss of the tobacco granules prepared from different tobacco materials were similar. Comparing to the tobacco granules prepared from flue-cured tobacco, the highest weight loss rate temperature of those prepared from tobacco stems, reconstituted tobacco, burley, cigar and oriental tobacco shifted towards lower temperature region. The weight loss rates of volatile compounds released from the tobacco granules prepared from tobacco stems and reconstituted tobacco were higher at the weight loss stage. During this stage, the proportion of the weight loss from flue-cured tobacco was the largest with the lowest amount of solid residues after pyrolysis. 2) The FTIR spectra indicated that the release of gaseous products from the tobacco granules prepared from different tobacco materials were almost the same, while the release temperature ranges were slightly different due to the differences of chemical components. The temperature ranges at which carbohydrates, phenols, alcohols and other hydroxyl-containing compounds released mainly concentrated in the range of 150-300 ℃. The releases of carbonyls, esters compounds and CO could be divided into two stages: 250-400 ℃ and around 500 ℃. NH₃ and CH₄ were released at temperatures higher than 500 ℃. 3) The bulk densities of the tobacco granules prepared from tobacco stems, reconstituted tobacco and cigar tobacco ranged from 0.54 to 0.56 g/cm3; they had higher smoke release rates and higher total smoke release amount although their bulk densities were lower than those made from other tobacco materials. Tobacco granules prepared from tobacco stems had the highest initial smoke release rate. Moreover, the releases of CO and CO₂ showed a similar trend to that of smoke release rate, i.e., the higher the smoke release rate, the higher the CO and CO₂ release rates would be.