金属盐对卷烟纸裂解致孔及主流烟气中CO释放量的影响

Pyrolysis of cigarette paper: effects of metal salts on pore formation and carbon monoxide release in mainstream smoke

为考察柠檬酸钾、醋酸钙、醋酸锌、氯化钙、氯化锌等不同金属盐对卷烟纸裂解行为及卷烟主流烟气中CO释放量的影响,采用热分析法研究卷烟纸的热裂解行为,采用压汞法和扫描电镜(SEM)法表征了卷烟纸微孔结构,并通过测试卷烟燃烧锥温度分布研究了金属盐对卷烟燃烧温度分布的影响。结果表明:1添加不同金属盐的卷烟纸对卷烟烟气CO释放量有不同的影响,柠檬酸钾促进了卷烟纸纤维的裂解致孔作用,使炭化线附近卷烟纸的孔容和微孔数目增多,扩散和稀释共同作用使主流烟气CO释放量显著降低;而醋酸锌、醋酸钙、氯化钙和氯化锌可抑制卷烟纸纤维的裂解致孔作用,使炭化线附近卷烟纸的孔容和微孔数目减少,主流烟气CO释放量显著增加。2与空白对照样相比,添加柠檬酸钾的卷烟纸,其卷烟在高温区域(750℃以上)燃烧锥的体积减小;而添加醋酸锌、醋酸钙、氯化钙和氯化锌的卷烟纸,其卷烟的高温燃烧锥体积增加。因此,卷烟纸中金属盐的添加对卷烟燃烧锥的体积和CO释放量具有显著的影响,卷烟高温区域燃烧锥的体积越小,其主流烟气中CO的释放量越低。

To investigate the effects of selected metal salts （potassium citrate, calcium acetate, zinc acetate, calcium chloride and zinc chloride） on the pyrolysis behavior of cigarette paper, the release of carbon monoxide in mainstream smoke and the temperature distribution of burning cigarette cone, the pyrolysis behavior of cigarette paper was studied by a combination of thermogravimetry analysis （TGA）, mercury porosimetry of cigarette paper, scanning electron microscopy （SEM）, and bespoke thermocouple array technique. The results indicated that： 1） Adding different metal salts into cigarette paper influenced the level of carbon monoxide in mainstream smoke differently; potassium citrate promoted the pore formation during the pyrolysis of fiber in cigarette paper, which increased the pore volume and micropore amount in the vicinity of char line, and the synergistic action of outward diffusion and dilution significantly decreased the CO release in mainstream smoke. However, the effects of zinc acetate, calcium acetate, calcium chloride and zinc chloride were opposite. 2） Comparing with the control （cigarette paper without adding metal salts）, adding potassium citrate into cigarette paper reduced the volume of burning cone of cigarette at high temperature （above 750 ℃）. On the contrary, adding zinc acetate, calcium acetate, calcium chloride and zinc chloride had an opposite effect on the high temperature region. Therefore, the addition of metal salts into cigarette paper significantly affected the volume of burning cone of cigarette and the release of CO in mainstream smoke. The smaller volume of burning cone at high temperature showed the less CO level in mainstream smoke.