Kinetic Parameters of Biomass Pyrolysis by TGA

Ming Zhai, Li Guo, Yu Zhang, Peng Dong, Guoli Qi, Yudong Huang

Abstract


Pyrolysis processes of typical biomass, such as corn stalk and birch chips, were investigated by thermogravimetric analysis (TGA). The apparent activation energy and pre-exponential factor were calculated with the adoption of the improved Coats-Redfern integral method, 46 types of common mechanism functions, and the least square and iterative methods. By applying basic parameters of biomass pyrolysis, a reaction rate constant, activation entropy and activation enthalpy, activation Gibbs free energy, and the steric-hindrance factor were all calculated. Results showed that biomass pyrolysis can be divided into two primary reaction zones (Event 3 and Event 4). Event 3 is focused by cellulose and hemicellulose. Event 4 is oriented by lignin and cellulose. The thermogravimetric curves of the two biomass types under carbon dioxide and nitrogen atmospheres were roughly similar. The reaction mechanism function is 1 - alpha. It is possible to use activation entropy to represent the pre-exponential factor and to use the steric hindrance factor to predict the reaction rate.

Keywords


Biomass pyrolysis; Thermogravimetric analysis (TGA); Reaction mechanism; Activation entropy; Steric hindrance factor

Full Text: PDF

Welcome to BioResources! This online, peer-reviewed journal is devoted to the science and engineering of biomaterials and chemicals from lignocellulosic sources for new end uses and new capabilities. The editors of BioResources would be very happy to assist you during the process of submitting or reviewing articles. Please note that logging in is required in order to submit or review articles. Martin A. Hubbe, (919) 513-3022, hubbe@ncsu.edu; Lucian A. Lucia, (919) 515-7707, lucian.lucia@gmail.com URLs: bioresourcesjournal.com; http://ncsu.edu/bioresources ISSN: 1930-2126