Kinetics analysis on isothermal torrefaction of sawdust in a fixed-bed reactor using the Coats-Redfern method and functional group analysis using FTIR spectroscopy
DOI:
https://doi.org/10.24191/mjcet.v6i1.20061Keywords:
Sawdust, Torrefaction, Kinetics, Coats-RedfernAbstract
In this study, torrefaction of sawdust was performed in a fixed bed reactor at different torrefaction temperature and holding times of 200-300 oC and 20-60 mins respectively under nitrogen atmosphere isothermally. It was determined that the mass yield decreased upon increasing torrefaction temperature from 200 to 300 oC and holding time 20 to 60 mins. This could be contributed by the complete elimination of hemicellulosic fraction and slight removal of cellulosic fractions of sawdust which occur at higher torrefaction temperature of 260-300 oC. The values of kinetics parameters such as activation energy, Ea and pre-exponential factor (LnA) for the torrefaction of sawdust at holding times of 20,40 and 60 mins were evaluated using the Coats-Redfern method. The activation energy for torrefaction of sawdust reduced from 48.2054 to 41.7662 kJ/mol when the holding time for the reaction was increased from 20 to 60 mins. It is determined that the torrefaction of sawdust at 60 mins is more reactive than at 20 mins holding time. FTIR analysis on raw and torrefied sawdust showed the presence of OH hydroxyl group, C-H alkane and C=O from ester or carboxylic acids groups.
References
Cai, W., Fivga, A., Kaario, O. & Liu. R. (2017). Effects of torrefaction on the physicochemical characteristics of sawdust and rice husk and their pyrolysis behavior by thermogravimetric analysis and pyrolysis–gas chromatography/mass spectrometry. Energy & Fuels 31(2), 1544-1554.
Chen, D., Zhou., J., Zhang, Q., Zhu.X. & Lu, Q. (2014). Upgrading of rice husk by torrefaction and its influence on the fuel properties. BioRes. 9(4), 5893-5905.
Ghani, W.A.W.A.K., Silva, G. & Alias. A.B. (2014). Physico-Chemical Characterizations of Sawdust-Derived Biochar as Potential Solid Fuels. The Malaysian Journal Of Analytical Sciences, 18(3), 724 – 729
Kumar, P., Kumar., P., Rao. P.V.C., Choudary, N.C., & Sriganesh., G.(2017). Sawdust pyrolysis: Effect of temperature and catalysts. Fuel, 199, 339-345.
Lim A.C.R., Chin, B.L.F., Jawad, Z.A., Hii. & K.L.(2016). Kinetic analysis of rice husk pyrolysis using Kissinger-Akahiro-Sunose (KAS) method. Procedia Engineering 148, 1247-1251.
Liu, Z. & Han., G. (2015). Production of solid fuel biochar from waste biomass by low temperature pyrolysis. Fuel 158, 159-165.
Mohamed, A.R., Nordin, N.N.A. & Salleh, N.H.M. (2019). Chemical Properties of Torrefied and Raw Sawdust. Journal of Advanced Research in Engineering Knowledge 6 (1), 7-14.
Nhuchhen, D.R. (2016). Prediction of carbon, hydrogen, and oxygen compositions of raw and torrefied biomass using proximate analysis. Fuel 180, 348-356.
Poudel, Jeeban & Sea Oh. (2014). Effect of torrefaction on the properties of corn stalk to enhance solid fuel qualities. Energies 7(9), 5586-5600.
Ren, S., Lei, H., Wang, L., Bu, Q., Chen, S. & Wu, J. (2013). Thermal behaviour and kinetic study for woody biomass torrefaction and torrefied biomass pyrolysis by TGA." Biosystems Engineering 116(4): 420-426.
So, C-L., & Eberhardt. T.L. (2018). FTIR-based models for assessment of mass yield and biofuel properties of torrefied wood. Wood Sci Technol 52:209–227.
Syafie, S.M., Othman, Z.& Hami, N. (2017). Potential utilization of wood residue in Kedah: A preliminary study. Journal of Technology and Operations Management, Special Issue, 60-69.
Wang, L., Várhegyi, G., & Skreiberg, Ø. (2014). CO2 gasification of torrefied wood: A kinetic study. Energy and Fuels, 28(12), 7582-7590.
Downloads
Published
How to Cite
Issue
Section
License
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
