Tobacco pyrolysis. Kinetic evaluation of thermogravimetric-mass spectrometric experiments

The thermal decomposition of two tobacco blends was studied by thermogravimetry-mass spectrometry (TGA-MS) at slow heating programs under well-defined conditions. The kinetic evaluation was based on a distributed activation energy model (DAEM) which is a suitable tool for complex materials of plant origin. Linear and non-linear (stepwise) heating programs were employed to obtain information for reliable kinetic modeling. Series of experiments were evaluated simultaneously by the method of least squares. Efforts were made to identify and describe kinetically the similarities between two, highly different tobacco samples as well as between the various mass spectrometric intensity curves. This was achieved by evaluating large series of experimental results and assuming several kinetic parameters to be common for both samples and/or a group of mass spectrometric intensities. The methods and considerations outlined in the paper may be helpful in the studies of biomass and other organic samples by a wider variety of experimental techniques including TGA-FTIR and time-resolved pyrolysis. (C) 2009 Elsevier B.V. All rights reserved.