The Optimal High Heating Value of the Torrefied Coconut Shells


  • R. Espina School of Engineering and Architecture, Ateneo de Davao University, Philippines
  • R. Barroca School of Engineering and Architecture, Ateneo de Davao University, Philippines
  • M. L. S. Abundo Engineering Graduate Program, School of Engineering, University of San Carlos (USC), Talamban, Cebu City, Philippines | Rolls-Royce@NTU Corporate Lab, Nanyang Technological University, Singapore


Coconut is a biomass resource that is abundant in tropical countries. In 2020, the Philippines planted 347 million coconut trees that produced 14.7 million tons of coconuts. The coconut shells (endocarp) are considered a waste material, which comprise 15.18% of each fruit and account for 2.2 million tons. The calorific value of raw coconut shells is 30.79MJ/kg. When torrefied at 275°C for 30 minutes holding time, the calorific value reached the optimal of 34.37MJ/kg, representing an increase of 11.64%. The mass yield (My) was 90.10% and the energy density was 111.64%, resulting in an energy yield of 100.59%.


coconut, shells, torrefaction, downdraft, gasifier, gasification, gas synthesis


Download data is not yet available.


I. Naim and T. Mahara, "Fuel Substitution for Energy Saving: A Case Study of Foundry Plant," Engineering, Technology & Applied Science Research, vol. 8, no. 5, pp. 3439–3444, Oct. 2018. DOI:

"Philippine Forestry Statistics."

statistics/philippines-forestry-statistics (accessed Apr. 05, 2022).

Forest Management Bureau, "Philippine Forestry Statistics," Department of Environment Natural Resources, 2020. [Online]. Available: [Accessed 7 November 2021].

"Coconut Statistics." (accessed Apr. 05, 2022).

"Philippine Statistics Authority | Republic of the Philippines." (accessed Apr. 05, 2022).

J. E. G. Van Dam, "Coir processing technologies. Improvement of drying, softening, bleaching and dyeing coir fibre/yarn and printing coir floor coverings," FAO/CFC, Rome, Italy, 2002.

R. Mudiyono and S. Sudarno, "The Influence of Coconut Fiber on the Compressive and Flexural Strength of Paving Blocks," Engineering, Technology & Applied Science Research, vol. 9, no. 5, pp. 4702–4705, Oct. 2019. DOI:

P. Basu, Biomass Gasification and Pyrolysis: Practical Design and Theory. Burlington, MA, USA: Academic Press, 2010.

M. Wilk and A. Magdziarz, "Hydrothermal carbonization, torrefaction and slow pyrolysis of Miscanthus giganteus," Energy, vol. 140, pp. 1292–1304, Dec. 2017. DOI:

A. Irawan, L. U. S., and M. D. I. P., "Effect of torrefaction process on the coconut shell energy content for solid fuel," AIP Conference Proceedings, vol. 1826, no. 1, Mar. 2017, Art. no. 020010. DOI:

B. V. Babu, "Biomass pyrolysis: a state-of-the-art review," Biofuels, Bioproducts and Biorefining, vol. 2, no. 5, pp. 393–414, 2008. DOI:

A. Bhavanam and R. C. Sastry, "Biomass Gasification processes in downdraft fixed bed reactors: a review," International Journal of Chemical Engineering and Applications, vol. 2, no. 6, pp. 425–433, 2011. DOI:

L. D. B. Pestano and W. I. Jose, "Production of Solid Fuel by Torrefaction Using Coconut Leaves as Renewable Biomass," International Journal of Renewable Energy Development, vol. 5, no. 3, pp. 187–197, Oct. 2016. DOI:

W.-H. Chen and P.-C. Kuo, "A study on torrefaction of various biomass materials and its impact on lignocellulosic structure simulated by a thermogravimetry," Energy, vol. 35, no. 6, pp. 2580–2586, Jun. 2010. DOI:

E. Dahlquist, Technologies for Converting Biomass to Useful Energy: Combustion, Gasification, Pyrolysis, Torrefaction and Fermentation. Boca Raton, FL, USA: CRC Press, 2013. DOI:

ASTM D1762-84(2021), Standard Test Method for Chemical Analysis of Wood Charcoal. West Conshohocken, PA, USA: ASTM International, 2021.

T. Cordero, F. Marquez, J. Rodriguez-Mirasol, and J. J. Rodriguez, "Predicting heating values of lignocellulosics and carbonaceous materials from proximate analysis," Fuel, vol. 80, no. 11, pp. 1567–1571, Sep. 2001. DOI:

S. D. Menon, K. Sampath, and S. S. Kaarthik, "Feasibility studies of coconut shells biomass for downdraft gasification," Materials Today: Proceedings, vol. 44, pp. 3133–3137, Jan. 2021. DOI:

M. Hasan, Y. Haseli, and E. Karadogan, "Correlations to Predict Elemental Compositions and Heating Value of Torrefied Biomass," Energies, vol. 11, no. 9, Sep. 2018, Art. no. 2443. DOI:

D. R. Nhuchhen and M. T. Afzal, "HHV Predicting Correlations for Torrefied Biomass Using Proximate and Ultimate Analyses," Bioengineering, vol. 4, no. 1, Mar. 2017, Art. no. 7. DOI:

P. Basu, "Torrefaction," in Biomass Gasification, Pyrolysis and Torrefaction, Second Edition., San Diego, CA, USA: Academic Press, pp. 87–145. DOI:

T. A. Mamvura and G. Danha, "Biomass torrefaction as an emerging technology to aid in energy production," Heliyon, vol. 6, no. 3, Mar. 2020, Art. no. e03531. DOI:

T. Milne, A. H. Brennan, and B. H. Glenn, Sourcebook of Methods of Analysis for Biomass and Biomass Conversion Processes. New York, NY, USA: Springer, 1990.

D. L. Klass, Biomass for Renewable Energy, Fuels, and Chemicals. San Diego, CA, USA: Academic Press, 1998.

T. R. Brown and R. C. Brown, Biorenewable Resources: Engineering New Products from Agriculture, 2nd ed. Chichester, West Sussex, UK: Wiley-Blackwell, 2014. DOI:

A. Friedl, E. Padouvas, H. Rotter, and K. Varmuza, "Prediction of heating values of biomass fuel from elemental composition," Analytica Chimica Acta, vol. 544, no. 1, pp. 191–198, Jul. 2005. DOI:

A. Ozyuguran, A. Akturk, and S. Yaman, "Optimal use of condensed parameters of ultimate analysis to predict the calorific value of biomass," Fuel, vol. 214, pp. 640–646, Feb. 2018. DOI:

R. P. Bates and K. Dolle, "Syngas Use in Internal Combustion Engines - A Review," Advances in Research, vol. 10, no. 1, 2017, Art. no. 32896. DOI:

T. A. Milne and R. J. Evans, Biomass Gasifier "Tars": Their Nature, Formation, and Conversion. Golden, CO, United States: National Renewable Energy Laboratory, 1998. DOI:

P. Basu, Combustion and Gasification in Fluidized Beds. Boca Raton, FL, USA: CRC Press, 2006. DOI:

S. A. Bellow, J. O. Agunsoye, J. A. Adebisi, F. O. Kolawole, and S. B. Hassan, "Physical properties of coconut shell nanoparticles," Kathmandu University Journal of Science, Engineering and Technology, vol. 12, no. 1, pp. 63–79, 2016. DOI:

S. H. Solangi, A. Q. Jakhrani, K. C. Mukwana, A. R. Jatoi, and M. R. Luhur, "Investigation of Quantity, Quality and Energy Content of Indigenous Sugarcane Trash in Naoshehro Feroze District, Sindh," Engineering, Technology & Applied Science Research, vol. 8, no. 6, pp. 3609–3613, Dec. 2018. DOI:


How to Cite

R. Espina, R. Barroca, and M. L. S. Abundo, “The Optimal High Heating Value of the Torrefied Coconut Shells”, Eng. Technol. Appl. Sci. Res., vol. 12, no. 3, pp. 8605–8610, Jun. 2022.


Abstract Views: 270
PDF Downloads: 124

Metrics Information
Bookmark and Share

Most read articles by the same author(s)