Effect of potassium inorganic and organic salts on the pyrolysis kinetics of cigarette paper

Abstract

The thermal behavior and burning characteristics of cigarette paper are critical in producing high quality product. In this paper, the catalytic effect of four potassium inorganic and organic salts on the pyrolysis kinetics of cigarette paper was investigated by using thermogravimetric analyzer coupled with Fourier transform infrared spectrometer (TGA–FTIR) in a temperature range of 30–900°C at the heating rate of 20°Cmin−1 under inert atmosphere. The results were analyzed based on three non-isothermal models available in the literature. The analyses of evolved gaseous products distribution accompanied with the mass loss process of cigarette paper samples were also conducted according to the evolved gas profile (EGP) and functional group profile (FGP). The results obtained from pyrolysis process indicate that there are three main stages such as water evaporation, cellulose pyrolysis and calcium carbonate decomposition. In the DTG thermograms the peak temperatures at maximum mass loss rate were decreased by the addition of four potassium salts with the following order: potassium salt KHCO3>potassium 1,2,3,4-butane tetracarboxylate (KBTCA)>potassium gluconate (KGL)>KCl, and the corresponding temperature reduction of 107, 57, 40 and 20°C, respectively. The kinetic parameters calculated by the Coats–Redfern and Zavkovic method are in good agreement with those obtained from the Viswanath–Gupta method. A general activation energy range of 134–252kJmol−1 and pre-exponential factor range of 1.13×1011 to 1.39×1019min−1 were proposed for cigarette papers with and without potassium salts. Experimental results showed that four studied potassium salts decreased the activation energy remarkably with the following descending order: KGL>KHCO3≈KBTCA>KCl. Except for potassium cations, the anions played a crucial role on the catalytic effects for the pyrolysis kinetics of cigarette paper.