Thermal decomposition kinetics and characteristics of Spartina alterniflora via thermogravimetric analysis

Pyrolysis of Spartina alterniflora (smooth cordgrass) was investigated by thermogravimetric analysis in a nitrogen atmosphere at heating rates of 5, 10, 20, and 40 degrees C/min. Main weight-loss was observed in smooth cordgrass at temperatures ranging from 200 degrees C to 360 degrees C, owing to release of 72%-74% of total volatiles. Pyrolysis characteristics such as distribution of pyrolysis products and thermal-decomposition rate significantly changed based on heating rate, but had no significant effect on the total yield of volatile matters. Activation energy was evaluated by four model-free methods, namely, Friedman, Flynn-Wall-Ozawa (FWO), Kissinger-Akahira-Sunose (KAS), and Kissinger methods. Experimental results showed that the activation energy obtained from the Kissinger method was in agreement with the average value of activation energy (183.6 kJ/mol to 183.4 kJ/mol) determined by FWO and KAS methods. Results of the master-plots method indicated that the most probable reaction model function was f (a) = (1 - a)(3.37) under activation energy of 183.5 kJ/mol. (C) 2014 Elsevier Ltd. All rights reserved.