Tobacco fractionation and its effects on pyrolysis chemistry

Abstract

Tobacco is a major cash crop in the world market. As a special biomass, it has relatively high extract content and particularity of mainly using its volatile components. The degrading of tobacco extractives may influence the reactant surface, the reaction energy and the product distribution during tobacco pyrolysis. However, the interplay among the tobacco extractive components and others during pyrolysis and its influence on the pyrolysis product distribution is not clear enough. Hence, the water-soluble tobacco fractionated component and ethanol-soluble tobacco fractionated component as well as the remaining solid phase component was obtained, followed by a comparative analysis of weighted product distribution (by weighted calculation of fractionated components, Weighted) and actual pyrolysis product distribution (Raw). Results indicates that polycondensation to 2,2'-methylenebis-phenol and volatilization of (S)− 3-(1-methyl-2-pyrrolidinyl) pyridine were both free from the interplay among components. The generation of CO2 was inhibited and the decomposition to produce furans, phenols and toluene was promoted to different degree by the interplay among components. Pyrolysis kinetic results showed that the conversion of 40% was a dividing line, below which the activation energy of Weighted was lower than Raw, above which, the activation energy of Weighted surpassed Raw, indicating that the synergistic pyrolysis between the components failed to play a significant role in promoting the devolatilization or the depolymerization, dehydration, and decarboxylation of small molecules, but could significantly promote the depolymerization of macromolecules and the subsequent decomposition reactions. Such results are critical to the advancement of tobacco utilization, improving reuse efficiency of tobacco extractives.