基于实时升温红外光谱研究烟草热解化学结构变化

摘要

In order to evaluate the properties and variations of chemical structures of pyrolyzed tobacco, real-time temperature-rising infrared spectrometry (RTR-IR) was applied to the online detection and analysis of flue-cured, burley and oriental tobacco, expanded tobacco, expanded cut stem and reconstituted tobacco at different pyrolysis temperatures. The results showed that: 1) The intensity variations of the same functional group in different tobacco samples differed slightly, while the intensities of different functional groups in the same sample differed significantly along with the change of temperature. 2) At the first main temperature interval of mass loss of tobacco (150 ℃-400 ℃), O—H, N—H, C—O, and C—N bonds degraded totally and there was only a trace of C O bond left, accompanied with a great amount of aromatic components formed,which became the primary functional groups in the char together with the C—H bond. The oxidative degradation of C—H bond and aromatic components principally occurred at the second temperature interval of mass loss (400 ℃-570 ℃). At the same time significant heat was released. The endothermic formation and transformation of inorganic salts were the main chemical reactions above 600 ℃.%为揭示烟草热解化学结构变化特性，利用实时升温红外光谱仪(RTR-IR)在线检测分析了烤烟、白肋烟、香料烟以及“三丝”的化学结构随温度的变化规律。结果表明：①不同烟草样品中相同官能团强度随温度变化略有差异，同一种烟草样品不同官能团强度随温度变化差异显著。②在烟草第一主要失重区(150℃~400℃)，O—H、N—H、C—O以及C—N降解完毕，C O仅有少量残留，同时生成大量芳香成分，其与C—H一同成为焦炭中主要官能团；在第二失重区(400℃~570℃)，主要发生C—H和芳香成分的氧化降解，并释放大量热量；在600℃以上，主要发生各种无机盐的吸热生成和转化反应。