Optimizing Palm Oil Recovery: CFD Insights into Sedimentation Tank Dynamics

The oil palm tree (Elaeis guineensis) is a major agricultural commodity in Malaysia, significantly contributing to the production of crude palm oil (CPO). Within the milling process, sedimentation is a critical stage that directly influences the quality of the final CPO product. Among the key parameters affecting sedimentation efficiency, fluid velocity plays a crucial role, particularly in controlling sludge blanket dynamics. This study investigates the optimal fluid velocity to enhance sedimentation performance, ensuring compliance with industry quality standards while minimizing the outflow cycle time of sedimentation tanks. To achieve this, Computational Fluid Dynamics (CFD) simulations were employed using COMSOL Multiphysics v6.3. A two-dimensional (2D) model of a sedimentation tank measuring 12.0 m in width and 4.0 m in height (total area: 48.0 m²) was developed. Inlet velocities ranging from 0.2 to 1.5 m/s were simulated using two turbulence models: k-ε and k-ω to assess their influence on flow behaviour, pressure distribution, and mass flux. Simulation results indicate that inlet velocities between 0.9 and 1.5 m/s yield optimal separation efficiency, minimizing oil losses to the sludge and maximizing oil recovery at the upper outlet. The study demonstrates the capability of CFD as a powerful tool for accurately simulating sedimentation tank performance, enabling real-time analysis and optimization of key operational parameters. This approach presents a cost-effective and practical solution for improving CPO quality and sedimentation efficiency in the palm oil mills, with the added benefits of reducing waste and enhancing overall process sustainability.