Pyrolysis Kinetics of Chestnut Fruit Shells
Hale Sütcü *
Department of Metallurgical and Materials Engineering, Faculty of Engineering, Zonguldak Bülent Ecevit University, Zonguldak, Türkiye.
*Author to whom correspondence should be addressed.
Abstract
After consuming chestnut fruit, their shells are considered waste and are essentially waste lignocellulosic biomass and should be recycled into the economy. This study focuses to evaluate in terms of pyrolysis. Firstly, the structural characterization of the shells was examined, followed by thermogravimetric analysis of pyrolysis and pyrolysis kinetics. The structure of the shells was examined by ultimate and proximate analyses, scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD). Pyrolysis was carried out at different heating rates of 10, 20, 30 and 40 °C/min up to 750 °C in a nitrogen atmosphere. It was observed that pyrolysis occurred in three stages. The effect of the heating rate on each stage of pyrolysis, such as initial and final temperature of the stages, max. pyrolysis temperature, max. pyrolysis rate, and total mass loss, was observed. All the temperature values in the pyrolysis stages are in a linear relationship with the heating rate. The Coats & Redfern kinetic model was used to determine the activation energy for each stage at different reaction degrees. The highest correlation value was accepted as the reaction degree for that stage. While there is no relationship between the reaction rate and activation energy for the second stage of pyrolysis, there is for the third stage. In this kinetic model, a kinetic compensation effect was also found between the activation energies and pre-exponential factors.
Keywords: Lignocellulosic biomass, chestnut fruit shell, thermogravimetric analysis, pyrolysis, kinetic analysis