葡萄糖裂解释放一氧化碳的影响因素

摘要

为考察烟叶中葡萄糖在卷烟燃烧过程中对烟气一氧化碳（CO）生成的影响，采用热重分析仪和裂解仪模拟卷烟燃烧过程中葡萄糖的热裂解，通过电化学法及红外散射法检测热裂解过程中CO的释放量变化，探讨了钾盐（柠檬酸钾、碳酸钾和硫酸钾）添加量（0%~4.0%，质量分数）、氧气浓度（0%~20%，体积分数）和升温速率（50℃/s~300℃/s）等因素对葡萄糖裂解产生CO的影响。结果表明：①有氧慢速裂解（10%O2、20℃/min）条件下，CO的释放过程与TG曲线的葡萄糖热解及残炭氧化两个阶段相对应，在此条件下，葡萄糖有氧裂解的CO产率约为无氧慢速裂解的2倍。②柠檬酸钾能降低葡萄糖的分解温度和CO的产率，且与CO产率存在明显的剂量效应关系。③在空气氛围中快速裂解（50℃/s~300℃/s）时，CO产率随着升温速率的增大而增加。④空气氛围、300℃/s条件下快速裂解时，柠檬酸钾、碳酸钾能降低葡萄糖的CO产率，但硫酸钾对葡萄糖裂解释放CO没有影响。%In order to investigate the influences of endogenic glucose in tobacco leaves on carbon monoxide (CO) release during cigarette combustion, the pyrolysis of glucose was simulated by a thermogravimetric analyzer (TG) and pyrolyzer, and the CO yield formed by pyrolysis was determined with an electrochemical method and FTIR method. Furthermore, the impacts of 0%-4.0% (mass fraction) of potassium salts (potassium citrate, potassium carbonate and potassium sulphate) addition, oxygen concentration (0%-20%, volume fraction) and heating rates (50 ℃/s-300 ℃/s) were also studied. The results showed that: 1) With oxygen-assisted pyrolysis under slow temperature ramp (10% of O2, 20 ℃/min), CO formation from glucose could be divided into a pyrolysis stage and a carbon residue oxidation stage, which corresponded with the two stages of mass loss curve. The CO yield in the presence of oxygen was about twice as high as it was under the inert condition and the slow programmed temperature. 2) CO yield and decomposition temperature of glucose were reduced by potassium citrate in an apparent dose-response relationship. 3) Under air atmosphere and fast heating (50 ℃/s-300 ℃/s), the CO yield increased with the increase of heating rate. 4) Under air atmosphere and at a heating rate of 300 ℃/s, CO yield was reduced by potassium citrate and potassium carbonate. However, the potassium sulphate had no noticeable effect on the CO yield from glucose.