Study of the decomposition of tobacco/citrate/SBA-15 mixtures in nitrogen and air atmospheres
Combustion is a complex physical-chemical process. The products of combustion strongly depend on the temperature and oxygen availability in the different zones of the cigarette. Potassium citrate is widely used as a cigarette ingredient, acting as a moisturizing and surface-active agent for flavor application and having the ability of reducing the amount of carbon monoxide and tar. SBA-15 has been studied as a catalyst for reducing the amounts of nicotine, tar and carbon monoxide.
In the present work, the effect of SBA-15 zeolite catalyst on the qualitative composition of gases produced during the pyrolysis of tobacco and tobacco-citrate mixtures was studied by TGA/FTIR, under N2 and air atmospheres.
Three processes are observed in the thermal decomposition of potassium citrate in both atmospheres; the first two occur at around 230 and 290°C and the third one occurs at 510°C in N2 and at 430°C in air. The addition of SBA-15 produces different and noticeable changes depending on the atmosphere used. Tobacco, tobacco-citrate and tobacco-citrate-SBA-15 samples present almost the same weight loss processes, though their intensity decreases when adding the citrate and the catalyst in both atmospheres. The presence of SBA-15 produces a separation of the last decomposition process into two processes in air. The evolution with the temperature of the more significant IR bands of the gases produced shows significant reduction, in both atmospheres, mainly when adding potassium citrate and SBA-15 to tobacco (except in N2 atmosphere for the R-O-H and R-O-R’, and carbonyl bands).
Acknowledgments: Financial support for this investigation has been provided by the Spanish “Secretaría de Estado de Investigación” del Ministerio de Economía y Competitividad (MAT2011-24991) and by the Generalitat Valenciana (PROMETEO/2012/015).