O. I. Ihenyen

The aim of this project was the design, fabrication, and testing of an easy-to-operate and affordable small-scale palm oil clarifier fit for farm use. This was accomplished by the design and selection of materials for the manufacture of the individual components of the clarifier, the production of the working drawings, and fabrication. A performance test, in terms of oil recovery rate, was carried out on the clarifier. On average, we had 91.30% and 91.54% oil recovery rates. Comparatively, these rates are within the range of the results from industrial and more automated systems with large-scale farms, which typically strive for recovery rates between 90% and 95%

Due to the numerous challenges associated with conventional small-scale palm fruit digesters, such as low processing efficiency, poor hygiene, high material losses, and susceptibility to corrosion, the aim of this project was to design, fabricate, and evaluate an improved vertical palm fruit digester capable of enhancing performance and durability in small- to medium- scale palm oil processing. The methodology adopted involved the design and construction of the digester using stainless steel to improve corrosion resistance and hygiene. Key components such as the digestion drum, shaft, and agitator were carefully fabricated and assembled to ensure efficient mixing and fruit maceration. Fresh palm fruit bunches were sourced, sterilized by boiling, and then processed in controlled batches of varying masses (7 kg, 9 kg, and 10 kg). The performance of the machine was evaluated based on digestion time, throughput capacity, and effectiveness of mesocarp breakdown, as well as the quality of sludge produced. The results obtained showed that the developed digester was capable of processing a total of 36 kg of boiled palm fruit in 1020 seconds, with digestion time increasing proportionally with batch size. The machine achieved an average throughput of approximately 127 kg/hr, demonstrating improved efficiency compared to traditional small-scale digesters. Additionally, the digester produced well-macerated mesocarp and uniform sludge, indicating effective fruit breakdown and improved potential for oil extraction. The use of stainless steel also eliminated corrosion issues observed in mild steel designs, thereby enhancing durability and operational hygiene. The developed vertical palm fruit digester offers a significant improvement in efficiency, reliability, and product quality, making it a viable solution for small-scale palm oil processors seeking increased productivity and reduced operational losses.

The global edible oil industry is dominated by palm oil due to its high yield, versatility, and economic importance. Although Nigeria was once the world’s leading producer of palm oil, its current contribution to global output is less than 2%, largely due to outdated and inefficient processing technologies, particularly at the small-scale production level. One of the critical stages affected is the clarification process, which significantly influences the quality of the final product.

This study focuses on the design and fabrication of an improved diesel-powered palm oil clarifier specifically intended for small-scale producers. The machine is developed to enhance processing efficiency, improve product quality, and reduce the labor-intensive and rudimentary methods currently in use. The design addresses key challenges in the clarification stage by introducing a more effective separation process, thereby minimizing impurities and improving oil yield and quality.

The proposed system is tailored to meet the needs of rural and small-scale oil palm farmers who lack access to advanced processing technologies. By improving the efficiency of palm oil clarification, the machine is expected to contribute to increased productivity, better product quality, and enhanced economic returns for local producers. The study concludes that the adoption of improved mechanized clarification technology is essential for revitalizing Nigeria’s palm oil sector and strengthening its competitiveness in the global market.

The palm oil industry continues to suffer from the limitations of traditional clarification methods, which result in significant oil losses, poor product quality, and low throughput, particularly among small-scale rural processors who lack access to mechanized systems. This project aimed to design and fabricate an improved small-scale palm oil clarifier that addresses these shortcomings through enhanced chamber geometry, controlled heating, and appropriate material selection. Specifically, the work sought to evaluate existing clarification technologies, design a compact multi-chamber unit, select thermally and chemically resistant materials, develop an integrated heating system, and validate the prototype through performance testing.
The clarifier was fabricated using 304H stainless steel, chosen for its superior corrosion resistance, thermal stability at elevated temperatures, and suitability for hygienic food-grade processing. The design incorporated a cylindrical crude palm oil tank, a settling tank, and a dryer unit all of which was interconnected to facilitate gravity-driven phase separation and residual moisture removal. A gas-fired burner was integrated to maintain the mixture within the optimal clarification temperature range of 85–90°C, reducing oil viscosity and promoting separation of oil, water, and sludge. Design calculations covering tank volume (116.29 litres per batch), heat energy requirements (approximately 15.3 MJ), surface area, and settling time using Stokes' law were all carried out to ensure the system was dimensionally and thermally appropriate for a small-scale processing scenario involving up to 200 litres per day.
Performance tests conducted on 1st and 3rd November 2025 yielded oil recovery rates of 91.30% and 91.54% respectively, both of which fall within the 90–95% benchmark typically reported for larger automated industrial clarifiers and represent a marked improvement over the 74.24% efficiency documented in comparable small-scale prototype studies. The total fabrication cost of ₦1,137,000 confirms that high-performance clarification equipment can be produced at an accessible cost for small-scale processors. These findings demonstrate that thoughtful engineering design, when grounded in local material availability and the practical realities of rural processing environments, can deliver results competitive with far more capital-intensive systems, offering a viable pathway to reduced oil losses, improved livelihoods, and stronger agricultural productivity across small-scale palm oil communities in Nigeria and similar regions.