The FUDMA Journal of Sciences recently published a study by Funmilayo Nihinlola Osuolale, Adejoke Oluseyi Alamu, Sarafadeen Ayinde Azeez, Isaac Abayomi Oluremi, Caleb Oluwadara Oke, Solomon Oluyemi Alagbe, Aminah Abolore Sulayman, and Oluseye Omotoso Agbede that explores how to turn agricultural leftovers into high-performing energy sources. As the global population grows and industrialization accelerates, the massive consumption of fossil fuels has led to severe environmental challenges, most notably the release of large amounts of carbon dioxide. To combat this, researchers are looking toward biomassBiomass is a complex biological organic or non-organic solid product derived from living or recently living organism and available naturally. Various types of wastes such as animal manure, waste paper, sludge and many industrial wastes are also treated as biomass because like natural biomass these More as a renewable, carbon-neutral alternative. However, raw biomass like rice husk and palm kernel shell often has undesirable traits, such as high moisture content and low energy density, which make it difficult to transport and burn efficiently. The researchers utilized a thermal pretreatment called torrefaction to overcome these hurdles, essentially roasting the material to upgrade its fuel properties.

The investigation revealed that temperature is the most critical factor in determining the quality of the final solid fuel. By heating the materials between 200°C and 300°C in an environment without oxygen, the researchers successfully transformed the biomass into a substance resembling fine coal. This process triggered significant chemical changes, specifically the removal of water and volatile organic molecules. As the temperature increased, the physical appearance of the materials shifted from light brown or orange to a deep, charcoalCharcoal is a black, brittle, and porous material produced by heating wood or other organic substances in a low-oxygen environment. It is primarily used as a fuel source for cooking and heating.   More black. This visual change coincided with a measurable increase in fixed carbon and a decrease in the oxygen-to-carbon ratio. These chemical shifts are vital because they mean the resulting biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More contains more energy per pound than the original raw waste, making it a much more potent fuel for industrial use.

When comparing the two types of waste, palm kernel shells emerged as the superior candidate for energy production. Under the most intense treatment conditions of 300°C for one hour, the palm kernel shells achieved an energy content of 22.89 megajoules per kilogram. In contrast, rice husks reached a lower peak of 18.93 megajoules per kilogram under the same conditions. This difference is largely attributed to the internal structure of the materials. Palm kernel shells contain a higher amount of lignin, a complex organic polymer that is more resistant to heat. This allowed the shells to retain more of their mass and energy during the roasting process compared to the rice husks, which degraded more quickly due to their higher hemicellulose content.

The structural analysis of the treated samples provided clear evidence of why these fuels perform so well. Microscopic imaging showed that the smooth, compact surfaces of the raw waste became rough and porous after treatment, riddled with tiny cracks and collapsed cell walls. This physical breakdown makes the material much easier to grind into powder, which is a necessary step for many industrial power plants. Furthermore, chemical testing showed a progressive loss of certain moisture-attracting groups, meaning the final product is less likely to absorb water from the air. This change is a massive advantage for storage, as it prevents the fuel from rotting or losing its heating value over time, a common problem with untreated agricultural waste.

Ultimately, the study demonstrates that torrefaction is a highly effective bridge between traditional farming and modern sustainable energy. By converting what is often considered trash into a valuable, coal-like treasure, the research promotes a circular economy where waste is minimized and renewable energy is maximized. The findings suggest that while both materials are useful, palm kernel shells offer the greatest potential for high-severity energy applications. This work provides a clear pathway for the biofuel industry to adopt more efficient practices, helping to reduce the world’s reliance on fossil fuels while providing a practical use for the millions of tons of agricultural residues generated every year.

Source: Osuolale, F. N., Alamu, A. O., Azeez, S. A., Oluremi, I. A., Oke, C. O., Alagbe, S. O., Sulayman, A. A., & Agbede, O. O. (2026). Torrefaction of palm kernel shell and rice husk for enhanced solid fuel energy performance. FUDMA Journal of Sciences, 10(2), 347-357.