Vol.7 (2017) No. 4 ISSN: 2088-5334 Design of Crude Palm Oil Monitoring System using Electrical Capacitance Tomography: A Conceptual Framework H. L. M. Ameran #,1 , E. J. Mohamad #,2 , R. A. Rahim #,3 , W.N.A. Rashid * , Z. Mansor + # Instrumentation and Sensing Technology (InSet), Department of Mechatronic and Robotic Engineering, Faculty of Electrical and Electronic Engineering, Universiti Tun Hussein Onn Malaysia, 86400 Batu Pahat, Malaysia E-mail: 1 hanis.liyana@yahoo.com, 2 elmy@uthm.edu.my, 3 ruzairi@uthm.edu.my * Faculty of Engineering Technology, Universiti Teknikal Malaysia Melaka, 76100 Durian Tunggal, Malaysia Email: norhisyam@utem.edu.my + Department of Electrical Engineering, Politeknik Merlimau, 77300 Merlimau, Malaysia Email:zulkifli@pmm.edu.my Abstract— In Crude Palm Oil (CPO) milling operations, the oil flow that has gone through separation process must be tested for its purity as wastes (e.g. palm oil mill effluent, water, sludge) tend to get carried along the process pipeline. At present, this procedure usually takes up to 5 days as samples of the flow needed to be verified biologically for its composition. Electrical Capacitance Tomography (ECT) systems that are able to provide the cross-sectional images of a closed content has proven the possibility of monitoring the composition of CPO flow in online manner. ECT systems are also able to provide other crucial flow information such as its velocity and flow regime that could help in controlling the processes. In this paper, a brief literature review of existing ECT systems are presented, then a conceptual design for developing an ECT system for visualizing and measuring CPO flow are presented along with the decision process of choosing suitable technique and hardware types for the new ECT system for CPO monitoring. A preliminary simulation study of the capability of the designed system to reconstruct images of water-oil flow phantoms is also presented. The simulation results show that the designed system is capable of reconstructing phantom images with error lower than 30 %. Keywords—Electrical Capacitance Tomography; flow measurement; water-oil flow I. INTRODUCTION Process tomography is a tomographic imaging technique that is able to provide cross-sectional images of the contents inside closed process pipes or reactors [1]. This technique is categorised into different system types where its difference depends on the type of sensors and principles used e.g. radiative [2]–[5], ultrasound [6], [7], ultrasonic [8]–[10], electromagnetic [11], [12], resistive [13]–[16] and capacitive sensors [17]–[20]. These different types of sensors provides different types of signal measurement which then will be processed and manipulated to provide concentration distribution of the materials inside the pipe. The materials’ concentration distribution is then used to reconstruct images that resembles pipe’s contents. Process tomography is a powerful tool especially for process engineer as it can provide crucial flow information such as flow’s concentration profile and velocity profile without the need to physically dissect the pipelines or disrupt the processes [21]. The obtained flow information can greatly aide in controlling process flow e.g. regulate an optimum flow speed, early detection of flow malfunction. Electrical Capacitance Tomography (ECT) system is a type of process tomography where its principle is to measure the permittivity of materials inside the pipe. Electrodes are placed around the pipe and capacitance values between different electrode pairs are measured. The capacitance values differs in accordance to the permittivity value of each dielectric material, thus ECT system is reliable for differentiating materials of the pipe’s content and suitable for measuring multiphase flows [22]. ECT systems also offers many other advantages such as robustness against environmental noise and high measurement speed. ECT systems have been successfully developed and installed in various industrial applications [23]; oil pipelines [21], [24], 1374