Thermal analysis and non-isothermal thermogravimetric kinetics analysis using coats-redfern method of a torrefied empty fruit bunches
Document Type
Article
Publication Date
12-1-2023
Abstract
Thermal and mechanistic behaviours of solid biofuel are essential for commercial exploitation. In this work, the suitability of torrefied EFB as a solid biofuel was evaluated by investigating its physicochemical characteristics, kinetics and reaction mechanism during pyrolysis. The pyrolysis behaviour of raw and torrefied EFB was predicted via thermogravimetric analysis, kinetic parameters via Coats-Redfern three pseudo-components model-fitting method and pyrolysis mechanism via Criado method with Z-master plot. The physicochemical properties of torrefied EFB improved significantly compared to raw EFB in terms of fuel properties such as carbon content (8%-41%), fixed carbon (79%-328%) and calorific value (7%-42%). The degradation rate of hemicellulose and cellulose of torrefied EFB increased when the torrefaction temperature increased from 225 degrees C to 300 degrees C, leading to lower char yield and overall activation energy to initiate the pyrolysis process. The model deduced that higher overall activation energy was exhibited by raw EFB (9.39 kJ/mol) than those of torrefied EFB ranging from 6.55-7.86 kJ/mol (300 degrees C-225 degrees C). Thermal degradation of hemicellulose from torrefied EFB dominated the process by about 74% compared to cellulose and lignin when torrefaction temperature increased from 225 degrees C to 300 degrees C. Torrefaction could convert the power law mechanism to nucleation and growth mechanism gradually, allowing for better EFB thermal decomposition as a whole.
Keywords
activation energy, empty fruit bunches, kinetic reaction mechanism, pyrolysis, torrefaction
Divisions
sch_che
Publication Title
Journal of Oil Palm Research
Volume
35
Issue
4
Publisher
Malaysian Palm Oil Board
Publisher Location
PO BOX 10620, KUALA LUMPUR, 50720, MALAYSIA