Thermogravimetric Kinetic Analysis of the Pyrolysis of Rice Straw

Abstract

A kinetic of the pyrolysis of rice straw is investigated with thermogravimetric analyzer with non-isothermal methods selected for analyzing solid-state kinetics data is presented. The weight loss was measured by TGA in nitrogen atmosphere. The samples were heated over a range of temperature from 298K to 973K with three different heating rates of 5, 10 and 15K min-1. The results obtained from thermal decomposition process indicate that there are two main stages such as active and passive pyrolysis. In the DTG thermograms the temperature peaks at maximum weight loss rate changed with increasing heating rate. The activation energy and pre-exponential factor obtained by Kissinger method are 172.62kJ mol-1, 1.456 × 1011 min-1, while, the same average parameters calculated from FWO and KAS methods are 192.66kJ mol-1, 1.287 × 1022 min-1 and 193.60kJ mol-1, 6.887 × 1015 min-1, respectively. Experimental results showed that values of kinetic parameters obtained from three different methods are in good agreement, but KAS and FWO methods are more efficient in the description of the degradation mechanism of solid-state reactions.