Kinetic Parameters of Biomass Pyrolysis by TGA

• Main Authors: Ming Zhai, Li Guo, Yu Zhang, Peng Dong, Guoli Qi, Yudong Huang
• Format: Article
• Language: English
• Published: North Carolina State University 2016-08-01
• Series: BioResources
• Subjects: Biomass pyrolysis; Thermogravimetric analysis (TGA); Reaction mechanism; Activation entropy; Steric hindrance factor; Thermogravimetric analysis (TGA); Reaction mechanism; Activation entropy; Steric hindrance factor
• Online Access: http://ojs.cnr.ncsu.edu/index.php/BioRes/article/view/BioRes_11_4_8548_Zhai_Kinetic_Parameters_Biomass_Pyrolysis
• ISSN: 1930-2126; 1930-2126

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.