Thermo-kinetics of Forest Waste Using Model-Free Methods

Thermal behaviour of pine needles (Pinus Roxburghii) is examined through a thermogravimetry technique. The dried samples of pine needles undergo the non isothermal decomposition at temperature range of 308 - 1173 K. The heating rates used for experimental purposes are: 5 °C min-1, 10 °C min-1 and 15 °C min-1. Kinetic parameters of thermal decomposition reactions of pine needles are obtained through the model-free schemes. The estimated values of activation energy and frequency factor derived from Kissinger method are 132.77 kJ mol-1 and 13.15 x107 min-1, respectively. Furthermore, the averaged values of the same kinetics parameters retrieved from the isoconversional methods are 82.38 kJ mol-1 and 74.833 kJ mol-1, 25.42 x1013 min-1 and 13.449 x1010 min-1, respectively. Instead of the Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira Sunrose (KAS) schemes, the kinetic parameters derived from the Kissinger method are relatively promising for the thermal decomposition process, since the kinetic parameters are highly affected by intermediate stages and overlapping of the concurrent reaction occurred during pyrolysis.