Torrefaction of Cassava Rhizome to Produce High-Grade Solid Biofuels

Main Article Content

Jarunee Khempila
Pumin Kongto


This research studied solid fuel production from cassava rhizome by torrefaction technology to enable its use in the energy sector. Cassava rhizomes (CR) were treated at a temperature range of 250–300 °C under a nitrogen atmosphere. The residence time was 30 minutes. The solid products were characterized in terms of their fuel properties and functional groups, including mass and energy yield, energy densification, ash content, ultimate analysis, and calorific value. In addition, the functional groups of organic compounds were identified by the Fourier transform infrared spectroscopy technique, and the Van Krevelen diagram was used for comparisons of the fuel properties with coal. The results indicated that pretreatment using torrefaction had a significant impact on the quantity and physicochemical properties of the solid product. The torrefied-CR at 300 °C had the lowest mass yield (47.6%), energy yield (66.4%), and content of oxygen (22.0%), however, resulting in the highest calorific value (24.81 MJ/kg), energy densification (1.4), and content of carbon (62.51%). The calorific value of solid products ranged from 18 to 24 MJ/kg, showing an increase of 6% to 39% compared to the raw biomass. The peak of C–O and C=O stretching in hemicellulose began to disappear at temperatures above 275 °C. When the torrefaction temperature was increased to 300 °C, the ash content slightly increased from 6.18% to 8.76%. Moreover, the oxygen-to-carbon and hydrogen-to-carbon ratios of solid products decreased to become close to lignite coal. The results indicated torrefaction is a pretreatment method for converting cassava rhizome into high-grade biofuel.


Download data is not yet available.

Article Details

How to Cite
Khempila J, Kongto P. Torrefaction of Cassava Rhizome to Produce High-Grade Solid Biofuels. J Appl Res Sci Tech [Internet]. 2022 Jun. 14 [cited 2023 Dec. 4];21(1):88-102. Available from:
Research Articles


Pattiya A. Bio-oil production via fast pyrolysis of biomass residues from cassava plants in a fluidised-bed reactor. Bioresour Technol. 2011;102(2):1959-67.

Jongpluempiti J, Tangchaichit K. Comparison proximate analysis and heating value between cassava rhizome and perennial Wood. Adv Mater Res. 2012;415–417:1693–6.

Chitsanucha S, Khwanruthai T. The study on efficacy charcoal from corncob and charcoal from cassava rhizome. In: The 3th National Conference KPRU. Kamphaeng Phet, Thailand; 608–13.

Günther B, Gebauer K, Barkowski R, Rosenthal M, Bues C-T. Calorific value of selected wood species and wood products. Eur J Wood Prod. 2012;70(5):755–7.

Shariff A, Noor N, Lau A, Ali M. A comparative study on biochar from slow pyrolysis of corn cob and cassava wastes. Int j sci res innov. 2016;10(12):767-71.

Rueangsan K, Kraisoda P, Heman A, Tasarod H, Wangkulangkool M, Trisupakitti S, et al. Bio-oil and char obtained from cassava rhizomes with soil conditioners by fast pyrolysis. Heliyon, 2021;7(11):e08291.

Acharya B, Sule I, Dutta A. A review on advances of torrefaction technologies for biomass processing. Biomass Conv Bioref. 2012;2(4):349–69.

Nakason K, Khemthong P, Kraithong W, Chukaew P, Panyapinyopol B, Kitkaew D, et al. Upgrading properties of biochar fuel derived from cassava rhizome via torrefaction: Effect of sweeping gas atmospheres and its economic feasibility. Case Stud Therm Eng. 2021;23:100823.

Tumuluru JS, Sokhansanj S, Hess JR, Wright CT, Boardman RD. A review on biomass torrefaction process and product properties for energy applications. Ind Biotechnol. 2011;7(5):384-401.

Negi S, Jaswal G, Dass K, Mazumder K, Elumalai S, Roy JK. Torrefaction: a sustainable method for transforming of agri-wastes to high energy density solids (biocoal). Rev Environ Sci Biotechnol. 2020;19(2):463–88.

Soponpongpipat N, Nanetoe S, Comsawang P. Thermal Degradation of Cassava Rhizome in Thermosyphon-Fixed Bed Torrefaction Reactor. Processes. 2020;8(3):267.

Mamvura TA, Danha G. Biomass torrefaction as an emerging technology to aid in energy production. Heliyon, 2020;6(3):e03531.

Granados DA, Velásquez HI, Chejne F. Energetic and exergetic evaluation of residual biomass in a torrefaction process. Energy. 2014;74:181–9.

Bai X, Wang G, Gong C, Yu Y, Liu W, Wang D. Co-pelletizing characteristics of torrefied wheat straw with peanut shell. Bioresour Technol. 2017;233:373–81.

Matali S, Rahman NA, Idris SS, Yaacob N, Alias AB. Lignocellulosic biomass solid fuel properties enhancement via torrefaction. Procedia Eng. 2016;148:671–8.

Friedl A, Padouvas E, Rotter H, Varmuza K. Prediction of heating values of biomass fuel from elemental composition. Analytica Chimica Acta. 2005;544(1):191–8.

Watanabe T, Shino A, Akashi K, Kikuchi J. Chemical profiling of jatropha tissues under different torrefaction conditions: application to biomass waste recovery. PLoS One. 2014;9(9):e106893.

Kosolkittiamporn S. Assumption test of one-way analysis of variance in social science research. J YRU. 2020;15(1):118-27.

Viroj J. One-way ANOVA and multiple comparison in public health research: a case study of hemorrhagic fever protection. Scimsu. 2015;34(3):304-11.

Dyjakon A, Noszczyk T, Smedzik M. The influence of torrefaction temperature on hydrophobic properties of waste biomass from food processing. Energies. 2019;12(24):4609.

Mamvura TA, Pahla G, Muzenda E. Torrefaction of waste biomass for application in energy production in South Africa. S Afr J Chem Eng. 2018;25:1–12.

Chen D, Gao A, Cen K, Zhang J, Cao X, Ma Z. Investigation of biomass torrefaction based on three major components: Hemicellulose, cellulose, and lignin. Energy Convers Manag. 2018;169:228–37.

Nakason K, Pathomrotsakun J, Kraithong W, Khemthong P, Panyapinyopol B. Torrefaction of agricultural wastes: influence of lignocellulosic types and treatment temperature on fuel properties of biochar. Int Energy J. 2019;19(4):253–66.

Lieskovský M, Jankovský M, Trenčiansky M, Merganic J. Ash content vs. the economics of using wood chips for energy: model based on data from central europe. Bioresources. 2017;12(1):1579–92.

Niu Y, Lv Y, Lei Y, Liu S, Liang Y, Wang D, et al. Biomass torrefaction: properties, applications, challenges, and economy. Renew Sustain Energy Rev. 2019;115:109395.

Ramos-Carmona S, Pérez JF, Pelaez-Samaniego MR, Barrera R, Garcia-Perez M. Effect of torrefaction temperature on properties of Patula pine. Maderas Ciencia y tecnología. 2017;19(1):39–50.

Pala M, Kantarli IC, Buyukisik HB, Yanik J. Hydrothermal carbonization and torrefaction of grape pomace: a comparative evaluation. Bioresour Technol. 2014;161:255–62.

Hadjiivanov K. Identification and characterization of surface hydroxyl groups by infrared spectroscopy. Adv Catal. 2014;57:99–318.

Yin Y, Yin J, Zhang W, Tian H, Hu Z, Ruan M, et al. Effect of char structure evolution during pyrolysis on combustion characteristics and kinetics of waste biomass. J Energy Resour Technol. 2018;140(7):072203.

Granados DA, Ruiz RA, Vega LY, Chejne F. Study of reactivity reduction in sugarcane bagasse as consequence of a torrefaction process. Energy. 2017;139:818–27.

Horikawa Y, Hirano S, Mihashi A, Kobayashi Y, Zhai S, Sugiyama J. Prediction of lignin contents from infrared spectroscopy: chemical digestion and lignin/biomass ratios of cryptomeria japonica. Appl Biochem Biotechnol. 2019;188(4):1066–76.

So CL, Eberhardt TL. FTIR-based models for assessment of mass yield and biofuel properties of torrefied wood. Wood Sci Technol. 2018;52:209-27.