Thermogravimetric analysis and reaction kinetics of lignocellulosic biomass pyrolysis

The elucidation of the biomass pyrolysis characteristics will provide valuable guidance for the design of pyrolysis devices. The pyrolysis kinetics characteristics of lignocellulosic biomass were studied by thermogravimetric analysis, and the main influencing factors, including biomass particle size, heating rate, and metal ion, were investigated. With a decrease in the particle size of rice straw and pine sawdust, the initial and final pyrolysis temperatures and the temperature of the maximum weight loss ratio decreased. Opposite results were obtained for Phoenix tree leaves. Furthermore, the initial release temperature of volatile matter and the temperature corresponding to the peak of the derivative thermogravimetric curves increased with an increase in heating rate. Moreover, the pyrolysis activity of rice straw decreased significantly after deashing but increased with the addition of potassium. The pyrolysis kinetics parameters were calculated by the Coats-Redfern, Doyle, and the distributed activation energy model (DAEM) methods. The apparent activation energy of pyrolysis was the lowest, varying between 30 and 70 kJ/mol, according to the fitting results of the Coats-Redfern method. The apparent activation energies calculated by the DAEM and Doyle methods are similar, and are 67.6, 245.8, and 271.8 kJ/mol for rice straw, pine sawdust and Phoenix tree leaves, respectively. (C) 2020 Elsevier Ltd. All rights reserved.