Pyrolysis characteristics and kinetics of algal biomass using tga analysis based on ICTAC recommendations

Abstract

In the present work, a kinetic study of the pyrolysis process of algal biomass was investigated using a thermogravimetric analyzer. The weight loss was measured in nitrogen atmosphere. The samples were heated over a range of temperature from 473 to 1273 K at three different heating rates of 278, 283, and 303 K/min at a constant N2 flow rate of 30 mL/min. The results obtained from thermal decomposition process indicate that there are three main stages such as dehydration, active, and passive pyrolysis. The maximum decomposition of the biomass samples occurred between 493–923 K, owing to release of 60–65 % of total volatiles. In the DTG thermograms, the temperature at maximum weight loss rate changed with increase in heating rate. The activation energy of the pyrolysis reaction was determined by model free Kissinger-Akahira-Sunose and Ozawa-Flynn-Wall methods. The Coats-Redfern method was used to obtain kinetic parameters such as activation energy, pre-exponential factor, and reaction order. Pyrolysis process was simulated with the obtained kinetic parameters and results are in good agreement with experimental data.