A Study On The Relationship Of Cigarette Burning Pyrolysis/distillation Process And Conventional Gas Components In Cigarette Smoke

With the improvement of people's living standard and the growing concern for health,"smoking is harmful to health" has attracted more and more attention,and our country has also issued a series of provisions in recent years for prohibiting smoking in public places.The harmful substances that affect health mainly exist in the cigarette smoke,and the chemical components in the cigarette smoke are formed after a series of chemical and physical processes,most of which are produced in the pyrolysis/distillation zone.Accordingly,global researchers in the tobacco science and technology areas have long carried out extensive researches on cigarette burning(especially on pyrolysis/distillation mechanism)and its effects on smoke gas products.However,we still have a long way to go in order to obtain a systematic and deep understanding of the very complicated pyrolysis/distillation processes during cigarette burning for formation of smoke gas.In addition,the influence of cigarette design parameters on pyrolysis/distillation condition in the combustion process and its relationship with release quantity of harmful smoke gas ingredients still need in-depth studies for clarification.In this thesis,we have established a gas chromatographic method enabling simultaneous analysis of some conventional smoke gas components to explore the puff-by-puff gas release law.The cigarette burning taper has been characterized by the thermocouple temperature measurement technology.The effects of cigarette material on the cone combustion temperature distribution and of tipping paper porosity on smoke gas dilution and gas diffusion in the process of cigarette combustion,as well as their influences on conventional gas composition in the mainstream smoke have been investigated,the cigarette combustion temperature distribution in relation to the fuel cone suction process between conventional gas generation amount have been investigated.The main contents are as follows.1.Using a gas chromatograph equipped with carbon molecular sieve chromatography column,we realized simultaneous quantitative analysis of O2,CO,CO2,CH4 and other conventional gas components in cigarette mainstream smoke,with high repeatability and accuracy.Analysis of puff-by-puff cigarette mainstream smoke showed that,with the increase of the number of puffs,the concentration of CO,CH4 and CO2 in flue gas has an increasing trend,but that of O2 shows a decreasing trend.Consumption of O2 was found to be positively correlated to production of CO and CO2 in flue gas.2.Tipping paper porosity and cigarette paper porosity as well as their effects on the cigarette combustion temperature at different locations were examined.Results showed that,with the increase of tipping paper porosity,the combustion characteristic temperature Ts and the combustion cone volume V0 roughly show a decreasing trend,while the distribution parameter N roughly show an increasing trend.The characteristic temperature T0.1 for suction became closer to that for static combustion with the increase of loading paper porosity,indicating that a change in the loading paper porosity can influence the cone combustion temperature to some extent.The cigarette burning temperatures at different locations behaved differently when different loading paper porosity was used.The increase in cigarette paper porosity did not notably affect the cigarette burning high temperature zone.Regarding the effects of cigarette paper porosity on the location-dependent cigarette combustion temperature,when cigarette paper porosity increased to a certain degree,we found no clear regularity in the location-dependent cigarette burning cone volume V0,characteristic temperature Ts and the distribution function N.3.The puff-by-puff release rules of conventional gas components in mainstream cigarette smoke(O2,CO,CH4 and CO2)are investigated by the use of five different kinds of tipping paper.The experimental data revealed that,with the increase of paper porosity,the release amounts of conventional gases(CO,CH4 and CO2)in cigarette mainstream smoke decrease but the release content of O2 increases.For the examined porosity of the five kinds of cigarette tipping paper,the conventional gas emissions(CO,CH4,CO2)from mainstream smoke increased but the residual O2 content decreased mouth by mouth.CO,CH4,CO2 diffusion rate increases with the tipping paper and air permeability increases with the unburned cigarette length increases.The relationship between the conventional gas composition and temperature distribution of cone during combustion have been studied,low,medium and high temperature region volume and conventional gas composition(CO,CO2)linear regression have been gotten,and correlation coefficients were 0.9944,0.9933,respectively.It can provide reliable basis for the relationship distillation/pyrolysis process with conventional gas composition between the burning cigarette.