Study On Reducing Carbonyl Compounds In Reconstituted Tobacco Smoke By Ag/TiO₂/CaCO₃ Composite Nanocatalyst

The volatile carbonyl compounds are an important class of harmful ingredients in reconstituted tobacco smoke. The volatile carbonyl compounds in reconstituted tobacco smoke such as formaldehyde, acetaldehyde, acetone,acrolein,propionaldehyde,crotonakiehyde, 2-butanone, butyraldehyde, etc., has been included in the list of regulatory elements recommended by the tobacco products control study group. Volatile carbonyl compounds could cause different levels of stimulation of the body's sensory organs and respiratory system during cigarette suction. In order to reduce the amount of volatile carbonyl compounds release in reconstituted tobacco smoke. In this paper, the physical and chemical properties of reconstituted tobacco were analyzed,and the pyrolysis process of reconstructed tobacco was investigated. Ag loaded TiO2 nanoparticles coated CaCO3 (Ag/TiO2/CaCO3) nanocatalyst was synthesized by hydrothermal synthesis method. The catalyst was added to reconstituted tobacco and the corresponding influences on the content of carbonyl compounds in reconstituted tobacco smoke were studied.The physicochemical properties of the four reconstituted tobacco were analyzed and compared,the differences of the fiber morphology distribution, microstructure,physical properties (tensile strength, air permeability and bulk thickness),reducing sugar content and organic acids content were investigated. The results showed that: the fiber morphology distribution in four samples differed greatly, the fiber length distribution of the imported sample M is more uniform. The sample M is better than sample A, B, C in the fiber composition and microporosity. The tensile strength of imported sample M is the lowest, the air permeability is the highest, and the tensile strength of domestic sample B is the highest. The content of reducing sugar and organic acids in imported sample M were lower than those of domestic samples A, B and C. In general the samples M were superior to the domestic samples A, B and C in terms of micro structure, physical properties (tensile strength, air permeability and bulk thickness), reducing sugar content and organic acids contentIn order to reduce the release of carbonyl compounds in reconstituted tobacco smoke, spindle-shaped nanocalcium carbonate particles was prepared from calcium oxide by carbonation reaction. Ag loaded TiO2 nanoparticles coated CaCO3(Ag/TiO2/CaCO3) nanocatalyst was synthesized by hydrothermal synthesis method using calcium carbonate,butyl titanate and silver nitrate as raw materials and ascorbic acid as reducing agent. The structures and compositions of the catalysts were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TG). The results showed that Ag loaded TiO2 nanoparticles are uniformly dispersed on the surface of the spindle-shaped calcium carbonate. Ag/TiO2/CaCO3 composite nanocatalyst was added to four kinds of reconstituted tobacco for thermogravimetric analysis experiment, and the effects on pyrolysis process were studied. The results show that the catalyst can affect the pyrolysis process of the reconstituted tobacco and change the arbohydrates,cellulose decomposition and carbon oxidation of two main weight loss stages during the pyrolysis process.Ag/TiO2/CaCO3 composite nanocatalyst were added to four kinds of reconstituted tobacco to test the content of volatile carbonyl compounds in pyrolysis flue gas and cigarette mainstream smoke, compared with the reconstituted tobacco without adding catalyst, the effects of catalyst on the release of volatile carbonyl compounds in reconstituted tobacco smoke were studied. First, the carbonyl compounds released release of the four reconstituted tobacco without the addition of the catalyst was determined. There were some differences in the release of carbonyl compounds of four kinds of reconstituted tobacco, and the imported sample M was lower than the other three kinds of domestic samples. The catalyst was respectively added to four kinds of reconstituted tobacco for thermal cracking in a tube furnace. The results showed that catalyst can effectively reduce the release of volatile carbonyl compounds in flue gas.The catalyst was added to reconstituted tobacco and the corresponding influences on the release of carbonyl compounds in mainstream smoke by smoking machine were studied.The results showed that by spray 2% catalyst (w%) evenly on reconstituted tobacco surfece the carbonyl compounds release was reducedeffectively.