Carbon dioxide-assisted Torrefaction of Maize Cobs by Thermogravimetry: Product Yield and Energy Recovery Potentials

  • Bemgba B. Nyakuma Benue State University
  • Samuel-Soma M. Ajibade Universiti Teknologi Malaysia
  • Victor B. Adebayo Malaysian-Japan International Institute of Technology, Universiti Teknologi Malaysia
  • Habib Alkali University of Maiduguri
  • Victor O. Otitolaiye Department of Health Safety & Environmental Management, International College of Engineering & Management, Seeb, Oman.
  • Jemilatu O. Audu Modibbo Adama University of Technology
  • Faizah M. Bashir University of Hail
  • Yakubu A. Dodo Istanbul Gelisim University
  • Abubakar S. Mahmoud King Fahd University of Petroleum and Minerals
  • Olagoke Oladokun Covenant University
Keywords: Carbon dioxide, Torrefaction, Maize Cobs, Thermogravimetry, Energy Recovery


The objective of this study is to examine the potential product yields and energy recovery of maize cobs (MC) through carbon dioxide-assisted torrefaction using thermogravimetric analysis (TGA). The CO2-assisted torrefaction of MC was performed from 240 °C to 300 °C (Δ 30 °C) for the residence time of 30 minutes based on the selected non-isothermal/isothermal heating program of the TGA. Furthermore, the physicochemical, microstructure and mineral characteristics of MC were examined. The results showed that the CO2-torrefaction of MC resulted in a mass loss (ML) ranging from 18.45% to 55.17%, which resulted in the mass yield (MY) ranging from 81.55% to 44.83%. The HHV of the solid product was in the range from 22.55 MJ/kg to 26 MJ/kg, which indicates the CO2-torrefaction process enhanced the energy content of MC by 40% – 60%. In conclusion, the findings showed that the CO2 torrefaction is a practical, sustainable, and cost-effective approach for the valorization of MC into a clean solid biofuel for enhanced energy recovery.

Author Biography

Habib Alkali, University of Maiduguri

Department of Agricultural & Environmental Engineering, University of Maiduguri, Maiduguri, Borno State, Nigeria.


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How to Cite
NyakumaB. B., M. AjibadeS.-S., AdebayoV. B., AlkaliH., OtitolaiyeV. O., AuduJ. O., BashirF. M., DodoY. A., MahmoudA. S., & OladokunO. (2022). Carbon dioxide-assisted Torrefaction of Maize Cobs by Thermogravimetry: Product Yield and Energy Recovery Potentials. Physics and Chemistry of Solid State, 23(1), 16-24.
Scientific articles (Physics)