Industrial & Engineering Chemistry Research, Vol.53, No.18, 7810-7820, 2014
Quantifying Gas-Phase Temperature inside a Burning Cigarette
Understanding the thermal conditions inside a burning cigarette is an important step in controlling chemical emissions and also meeting reduced ignition propensity regulations. The last detailed experimental study of the thermal physics inside a burning cigarette was published more than 3 decades ago. Since then, modern commercial cigarettes have evolved considerably in designs and materials used. This study examined gas-phase combustion temperatures using Kentucky research reference cigarettes (3R4F) over two consecutive puffs taken by a smoking machine operating under the standard ISO puffing parameters. A number of thermal physical parameters (temperatures and temperature gradients in different spots versus time) were measured to characterize the alternating smoking cycle (puffing smoldering puffing). The dynamic distributions of coal volumes associated with different temperature ranges were measured, and a mathematical equation was used to model the distributions of volumes. Two-dimensional temperature and temperature gradient contours were constructed, which gave unparalleled insight into the heterogeneous heating of cut tobacco during cigarette burning. In addition to understanding cigarette combustion physics, the information obtained is useful in guiding analytical pyrolysis studies aimed at assessing precursor-smoke toxicant relationships and the fate of tobacco ingredients added to cigarettes.