Present Practice and Review of On-Line Measurement and Control Possibilities in Oil Processing Quality Control

摘要

In the last decades, significant improvement has been made in the field of crushing and refining, as well as in packaging techniques. Developments in processes, equipment, and field devices have made it possible to apply high-capacity, on-line production plants with advanced automation. On-line measurement and control of variables is essential in order to reduce the operating costs, to keep the process conditions within the optimum range, to ensure good and stable product quality, and to reduce the risk of human effects. In this study, an overview is given of the present and future possibilities of on-line quality control in the following areas: (1) Online, near-infrared spectroscopy (NIR) has been applied in the everyday quality control of crushing plants in order to obtain fast information both on the dehulling process and on the quality of the meal produced. This is a pollution-free and labor-saving technique that provides multicomponent analysis in real time, good precision, and low maintenance. Recent developments in light sources, optical fibers, detectors, and computer hardware and software systems have minimized the problems with NIR on-line analyzers. (2) Built-in turbidimeters have been applied successfully in crude and refined oil lines to control the presence of solid particles. (3) Effectiveness of chlorophyll removal during bleaching has been checked continuously by applying an on-line, dual-beam, visible spectrophotometer in the range of 0.02 to 0.08 ppm of chlorophyll. On-line measurement of chlorophyll provides real-time data and helps in decreasing the amount of bleaching earth. The future development of sensors, detection systems, and software programs will widen the application range, providing the plant with improved efficiency, optimized operating conditions, and better quality inspections.