306 JOURNAL OF OIL PALM RESEARCH 30 (2) (JUNE 2018) FATAH YAH ABD MANAF* and ANDREW YAP KIAN CHUNG* ABSTRACT The clarification operation in a palm oil mill is an important processing step that should be carefully handled with as much care as possible. As the oil loss in the clarification processes is a major source of oil loss in the overall milling operation, there is an urgent need to improve the crude oil dilution control for efficient oil recovery. Currently, there are no reliable methods to maintain the oil to crude oil ratio. As a result, no automatic dilution control is in practice even when mill throughputs are widely fluctuating. The trend to produce crude palm oil with low (<1.5%) free fatty acid (FFA) appears to be increasing among the millers as it commands a premium price in the world markets. In order to meet this demand, it will be worthwhile to use the near infrared (NIR) analyser for rapid analysis of the crude oil. It is also more efficient than the conventional method. Field trial results have shown that the NIR On-line system can be used not only to control the water dilution at an average of 39% to 40% of the crude oil but also to monitor the FFA content below 1.5% for automatic premium oil segregation during the palm oil processing. Keywords: near infrared (NIR), crude oil dilution, automatic control, premium oil, FFA. Date received: 9 August 2017; Sent for revision: 16 August 2017; Received in final form: 24 October 2017; Accepted: 26 January 2018. * Malaysian Palm Oil Board, 6 Persiaran Institusi, 43000 Kajang, Selangor, Malaysia. E-mail: fatahyah@mpob.gov.my AUTOMATIC CRUDE OIL DILUTION CONTROL WITH PREMIUM OIL SEGREGATION USING NEAR INFRARED (NIR) ON-LINE SYSTEM INTRODUCTION The milling technology related to crude oil dilution control has not made any significant advances in the last 30 years. As the palm oil production has grown rapidly in recent years it is time the milling operation also considers the introduction of an automatic system into the process line. Having accurate, current and real time data on process parameters and correcting them to achieve the optimum values would enhance the efficiency in the process operation. The aim of this study is to establish a control system for water dilution and segregate crude palm oil based on free fatty acid (FFA) content. AUTOMATIC CRUDE OIL DILUTION CONTROL The crude palm oil (CPO) released by the twin screw presses is a mixture about 55% oil, 35% water and about 10% solids (Maycock, 1987). Its inability to flow in the oil gutter has made it necessary for it to be diluted with water with the approximate volume being 40% of the crude oil. After dilution, the desired ratios of the crude oil components would be about 39% oil, 54% water and 7% solids (Mongana Report, 1955). If the press throughputs are consistent the dilution control may be maintained at the desired ratios without any issues by diluting a fixed amount of water flowing through a weir. But unfortunately the number of presses in operation at any point in time cannot be fixed as it is dependent on many factors like the need to stop a press when the digester level drops below three-quarter full. In such cases the water dilution valve has to be Journal of Oil Palm Research Vol.30 (2) June 2018 p. 306 – 314 DOI: https://doi.org/10.21894/jopr.2018.0012