卷烟纸裂解致孔对主流烟气中HCN释放量的影响

Effects of pore formation during cigarette paper pyrolysis on release of hydrogen cyanide in mainstream cigarette smoke

为考察助燃剂K/Na比对卷烟纸裂解致孔及主流烟气氢氰酸(HCN)释放量的影响,采用FS300纤维裂解仪表征卷烟纸纤维的裂解情况,用扫描电镜(SEM)表征卷烟纸的微孔结构,用燃烧温度测试仪研究卷烟燃烧锥温度分布与主流烟气中HCN释放量的关系。结果表明:1提高卷烟纸助燃剂K/Na比可促进纤维的裂解致孔作用,使得炭化线附近卷烟纸的微孔数目增多,在卷烟燃烧过程中可使炭化线附近卷烟纸的扩散率和透气度增大,从而促进HCN向侧流烟气中扩散并增加空气的稀释作用,使主流烟气中HCN的释放量降低;2增加卷烟纸助燃剂K/Na比可降低卷烟的燃烧温度,使得卷烟燃烧过程中HCN的释放量减少。在上述两方面的共同作用下,卷烟主流烟气中HCN的释放量明显降低,其最大降幅可达27.3%。

To investigate the effects of K/Na ratio in burn additives in cigarette paper on the pore formation during cigarette paper pyrolysis and its effect on the release of HCN in mainstream cigarette smoke, the fiber pyrolysis behavior of cigarette paper was characterized by a FS300 fiber pyrolyzer. The micropore structure in cigarette paper was further characterized by scanning electron microscope （SEM）, and the relationship between the temperature distribution in cigarette burning cone and the release of HCN in mainstream cigarette smoke was investigated by modularized fine thermocouple. The results showed that： 1） The increase of K/Na ratio in burn additives promoted the pore formation by fiber pyrolysis, increased the amount of micropores and improved the diffusivity and permeability of cigarette paper in the vicinity of char line, which facilitated HCN diffusion and air dilution; the release of HCN in mainstream cigarette smoke was thus decreased during puffing. 2） The increase of the K/Na ratio in burn additives decreased the combustion temperature of cigarette paper and the release of HCN during smoking. As a result, the release of HCN in mainstream cigarette smoke wassignificantly reduced with the maximum reduction at 27.3%.