ABSTRACT
Utilizing oil palm trunk (OPT) residue as a co-fuel in coal-fired plants offers an environmentally favorable solution to agricultural waste disposal and fossil fuel combustion impacts. This study investigates the potential of hydrochar from OPT (HTC-OPT) as a coal-like solid fuel for co-combustion. The combustion characteristics of coal, HTC-OPT, and their blends (10–50% HTC-OPT) were analyzed via thermogravimetric analysis with heating rates ranging from 10 to 30°C/min. The Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) models were employed to explore co-combustion interactions and kinetic parameters. Results reveal enhanced combustion efficiency with HTC-OPT addition to coal. Higher HTC-OPT ratios correlate with increased maximum combustion rates, ignition and comprehensive combustibility indices, and decreased ignition and burnout temperatures. Additionally, blended fuels exhibit a proportionally synergistic co-combustion interaction. Both KAS and FWO models indicate similar trends in activation energies, with the lowest values (49.94 kJ/mol for KAS and 60.90 kJ/mol for FWO) at a 10% HTC-OPT ratio.
GRAPHICAL ABSTRACT
Highlight
The co-combustion behavior of bituminous coal and oil palm trunk hydrochars was investigated.
The addition of HTC-OPT to coal enhances its combustion efficiency.
The synergistic co-combustion interaction of mixed fuels is directly proportional to the HTC-OPT ratio.
List of abbreviation
Abbreviations | = | |
DTG | = | Differential thermogravimetric |
FWO | = | Flynn-Wall-Ozawa |
HHV | = | High heating value |
HTC | = | Hydrothermal carbonization |
HTC-OPT | = | Oil palm trunk hydrochar |
ICTAC | = | International Confederation for Thermal Analysis and Calorimetry |
KAS | = | Kissinger-Akahira-Sunose |
OPT | = | Oil palm trunk |
TG | = | Thermogravimetric |
TGA | = | Thermogravimetric analysis |
Symbols | = | |
α | = | Conversion degree or fraction of material combusted |
β | = | Rate of heating |
f(α) | = | Function associated with reaction mechanism |
A | = | Pre-exponential factor |
Di | = | Ignition index |
Ea | = | Activation energies, KJ/mol |
R | = | Gas constant |
Rmax | = | Maximum rate of mass loss, wt%/min |
Rmean | = | Mean rate of mass loss, wt%/min |
Si | = | Comprehensive combustibility index |
t | = | Duration of the process, min |
ti | = | Ignition time, min |
tm | = | Time corresponding to the maximum rate of mass loss, min |
T | = | Absolute temperature, K |
Tb | = | Burnout temperature, K |
Ti | = | Ignition temperature, K |
Tm | = | Maximum combustion rate temperature, K |
TGc | = | Measured experimental weight loss of pure coal |
TGb | = | Measured experimental weight loss of HTC-OPT |
m | = | Instantaneous mass, g |
m0 | = | Starting mass, g |
mf | = | Ending mass, g |
xb | = | Proportion of HTC-OPT by mass in the blend |
xc | = | Proportion of coal by mass |
Acknowledgements
We express gratitude for the financial assistance received from Thailand Science Research and Innovation (TSRI). Our appreciation also goes to BLCP Power Limited and Suksomboon Palm Oil Co., Ltd. for supplying the bituminous coal and oil palm trunks used in this study.
Disclosure statement
No potential conflict of interest was reported by the authors.
Supplementary material
Supplemental data for this article can be accessed online at https://doi.org/10.1080/15567036.2023.2289556
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Funding
Notes on contributors
Lalita Attanatho
Lalita Attanatho is a senior researcher at the Expert Centre of Innovative Clean Energy and Environment, Thailand Institute of Scientific and Technological Research. She earned her Ph.D. in Chemical Engineering from Oregon State University. Her research is focused on the thermochemical conversion of biomass and the valorization of industrial wastes and agricultural residues into high-valued products.
Amornrat Suemanotham
Amornrat Suemanotham is a senior researcher at the Expert Centre of Innovative Clean Energy and Environment, Thailand Institute of Scientific and Technological Research. She earned her Ph.D. in Chemical and Environmental Engineering from University of California, Riverside. Her research interests include the thermochemical conversion of biomass and the transformation of waste materials into high-valued products.
Natthawan Prasongthum
Natthawan Prasongthum is a researcher at the Expert Centre of Innovative Clean Energy and Environment, Thailand Institute of Scientific and Technological Research. She earned her Ph.D. in Petrochemistry from Chulalongkorn University. Her research focuses on the catalytic conversion, biomass utilization and synthesis of carbon-based materials.
Zsuzsanna Czégény
Zsuzsanna Czégény is a senior research fellow at the HUN-REN Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungary. She earned her Ph.D. in Chemistry from Eötvös Loránd University. Her research interests include the thermal decomposition of polymers, biomass materials and their mixture.
Yoothana Thanmongkhon
Yoothana Thanmongkhon is a senior researcher at the Expert Centre of Innovative Clean Energy and Environment, Thailand Institute of Scientific and Technological Research. He earned his Ph.D. in Chemical and Environmental Engineering from University of California, Riverside. His areas of interest are biomass utilization and renewable energy.