Electrical Capacitance Tomography for Multiphase Flow Monitoring in Palm Oil Processing: Advances, Challenges, and Industrial Opportunities

Multiphase flow monitoring remains a major challenge in palm oil processing, particularly for oil–water separation, product quality control, and process optimization. Electrical Capacitance Tomography (ECT) is a noninvasive, radiation-free technique that enables real-time visualization of permittivity distributions within opaque multiphase systems. Recent developments in sensor design, sensitivity modeling, and machine learning-based image reconstruction have improved imaging accuracy, noise tolerance, and computational efficiency. However, industrial adoption in palm oil mills remains limited by low dielectric contrast, calibration drift, sensor fouling, scale-up constraints, limited field validation, and difficulties in integrating ECT with existing control systems. This review critically evaluates recent developments in ECT and their applicability to palm oil processing. It compares ECT with alternative monitoring techniques, examines experimental and pilot-scale implementations, and identifies key technical, operational, and economic barriers to industrial deployment. Attention is given to machine learning assisted reconstruction, digital twins, Industry 4.0 integration, cybersecurity, data communication, interoperability, and commercialization requirements. The review also discusses machine learning, digital twins, Industry 4.0 integration, and commercialization requirements. A conceptual implementation pathway is proposed based on published laboratory, pilot-scale, and industrial studies. The findings provide a practical reference for researchers, technology providers, and mill operators seeking to advance ECT from laboratory development towards reliable, real-time monitoring and intelligent process control.