Thermogravimetry study of pyrolytic characteristics and kinetics of the giant wetland plant Phragmites australis

Abstract

The pyrolytic characteristics and kinetics of wetland plant Phragmites australis was investigated using thermogravimetric method from 50 to 800 degrees C in an inert argon atmosphere at different heating rates of 5, 10, 25, 30, and 50 degrees C min(-1). The kinetic parameters of activation energy and frequency factor were deduced by appropriate methods. The results showed that three stages appeared in the thermal degradation process. The most probable mechanism functions were described, and the average apparent activation energy was deduced as 291.8 kJ mol(-1), and corresponding pre-exponential factors were determined as well. The results suggested that the most probable reaction mechanisms could be described by different models within different temperature ranges. It showed that the apparent activation energies and the corresponding pre-exponential factors could be obtained at different conversion rates. The results suggested that the experimental results and kinetic parameters provided useful information for the design of pyrolytic processing system using P. australis as feedstock.