Enhancement of Energy Content of Palm Kernel Shell (PKS) Using Particle Size Effects Approach

Abstract:

This study presents a report on the energy content enhancement of biomass derived from palm kernel shells (PKS) by varying the sample sizes using a developed hammer mill machine. A hammer mill was designed, simulated, and constructed to efficiently mill palm kernel shells into various particle sizes. Finite Element Analysis (FEA) was performed on the hammer mill’s frame and shaft, ensuring the structural integrity of the machine under operational loads. The machine’s rotor, crushing chamber, hammers, sieves, and prime mover were strategically engineered to achieve precise size reduction while maintaining operational efficiency and durability. The energy content of the selected biomass was evaluated for the control PKS sample and the milled PKS sample of two different particle sizes (0.4 and 0.6 mm). The main objective of this research was to examine palm kernel shells' energy potential by analysing the impact of particle size reduction on their energy content. To evaluate the energy characteristics of the processed biomass (grain size reduction), proximate and ultimate analyses were conducted on each particle size fraction, assessing parameters such as moisture content, volatile matter, ash content, fixed carbon, elemental composition (carbon, hydrogen, oxygen, nitrogen, and sulfur), and calorific value. The results revealed a direct correlation between particle size and energy content, with finer particles exhibiting improved combustion properties due to increased surface area and enhanced reactivity. It is found that higher carbon content of the milled PKS samples (54.5% at 0.4 mm and 48.37% at 0.6 mm), representing 49.4% and 43.04% enhancement, respectively, over the control PKS sample before the milling process was achieved in this study. The results of which yield a 3.36% energy content increment in terms of particle size variation from 0.4 to 0.6 mm, highlighting enhanced energy efficiency in this work. The attained reduced nitrogen and sulfur content of the milled samples in this work contributes to lower greenhouse gas emissions, making them a more environmentally sustainable biofuel option. These findings elucidate the potential of particle size optimization as an effective approach for improving the energy content of PKS, thereby enhancing its suitability as a clean and efficient bioenergy source.

• Periodical: Applied Mechanics and Materials (Volume 934)
• Pages: 139-155
• DOI: https://doi.org/10.4028/p-1ek6wC
• Online since: February 2026
• Authors: Taiwo Stephen Mogaji*, A.A. Amuleya, D.A. Jesugoroye, D.C. James, A.M. Akinwole, M.C. Elaine
• Keywords: Energy Content, Enhancement, FEA, Hammer Mill Machine, Particle Size, PKS, Proximate Analyses, Ultimate Analyses

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