Research For The Adsorption Of Volatile Carbonyl Compounds In Cigarette Mainstream Smoke

The Volatile carbonyl compounds in cigarette mainstream smoke are an important class of harmful ingredients, seriously affecting the sensory quality of cigarette and consumers'health. So, how to decrease the content of volatile carbonyl compounds in the mainstream smoke become a major challenge in the development of tobacco industry. This paper first studied the acetaldehyde adsorption abilities of some materials, and the materials which have relatively strong absorption ability have been selected and modified. Also, the abilities of the modified materials, which have good acetaldehyde adsorption abilities, to decrease the content of volatile carbonyl compounds in the mainstream smoke were evaluated by added into the filter tip.In the study, a static acetaldehyde adsorption apparatus has been established to determine the materials'acetaldehyde adsorption abilities, and the optimal experimental conditions are also determined. In this apparatus, the concentration of acetaldehyde solution changed after the materials'adsorption of the acetaldehyde gas in the sealed bottle, thus, the adsorption abilities of the materials could be evaluated by measuring changes in the concentration of acetaldehyde. The apparatus'optimal experimental conditions are as follows: the concentration of acetaldehyde solution 0.4%(w/w),adsorbent's weight 0.8g,temperature 35℃,and the adsorption time 48h.In this experimental conditions, the acetaldehyde adsorption abilities of activated carbon, sodium bisulfite, sodium carbonate, potassium carbonate, degumming silk, melamine and chitosan were studied, and the results showed that activated carbon, sodium bisulfite, and chitosan have relatively stronger absorption rate, which are 22.3%,51.9% and 51.0%.While,the effects of other materials on the acetaldehyde adsorption were not significant.Then the activated carbon was separately modified with acids, bases, oxidants, multi-amino substance and chitosan/ copper sulfate. The experiments have suggested that: the activated carbon modified with chitiosan and copper sulfate represented the best acetaldehyde adsorption ability. When the concentration is fixed at 1%(w/w), the best optimum modified conditions are as follows: temperature 20℃, pH 4.8, time 10 h, copper sulfate solution (water: copper sulfate = 13:1) 10 g. The adsorption properties of the sample obtained under the optimum conditions has increased by 42.3% compared to the origin activated carbon.Chitosan is also modified in this paper with different methods such as different drying methods, chelating with Cu ions, reacting withβ-cyclodextrin and polyethylene polyamine, preparation of metal microspheres and so on. The results showed that: the spray-dried chitosan has the best adsorption properties, which is significantly improved by 37.7% than the original sample, and the optimum experiment conditions are: chitosan's concentration 1.5%(w/w),inlet temperature 160℃and outlet temperature 80℃.The activated carbon modified with chitiosan and copper sulfate were applied to the cigarette by added into the filter tip, and the effects on the mainstream smoke have been studied. The results showed that: the content of volatile carbonyl compounds was significantly decreased, meanwhile, the tar, nicotine and carbon monoxide content were lowered and the moisture content was increased .When 20mg modified activated carbon was added, it had little impact on the sensory quality, however, could decrease the content of the volatile carbonyl compounds in the mainstream by 45.0%,which is 14.4% higher than that of original activated carbon.