DETERMINATION OF OPTIMUM VALUE OF PARAMETERS INVOLVED IN MECHANICAL EXPRESSION OF PALM KERNEL OIL.

Abstract

ABSTRACT Investigation was conducted to evaluate the performance of the focally the determlnatton of fabricated screw expeller used for the experiments. It was found that applied pressure was the main factor influencing the performance of the expeller. The effect of the applied pressures on the expression temperature, pressing time, oilyicld from palm kernel, expeller feed rate, oil extraction rate and the extraction efficiency was investigated. The highest extraction efficiency of the expeller was found to be 84.51 percent. Experiments were also performed on the screw expeller to determine the effects of preheat temperature in itbe presence and absence of water, applied pressures, and kernel moisture content on palm kernel oil yield. These main effects were found to be statistically significant in both cases. In the determination of the kernel optimum oil yield point, a mathematical model was developed using the statistical package for social sciences (SPSS) . The optimum oil yield for the range of variables (factors) considered in this study was found to be 2.133 kq or 2.311 litres of oil from 5 kg of palm kernel, (that is 89% of the oil in the kernel) at kernel moisture content between 5, to 5.60 percent, preheat temperature of 120°C and applied pressure of 59 Mtla for preheating in the absence of water or any other medium. The maximum oilyield of 2.107 kg or 2.32 litres (88%) was obtained at moisture content between 2.85 to 3 percent, preheat temperature of 120°C and applied pressure of 59 Mpa for preheating in the presence of water. Although preheating in the presence of water has been found to improve the quality of palm kernel oil, higher pressure Is required to completely express the whole oil from the kernel than ., in the preheating in the absence of water. The effect of duration of pressing in minutes on oilyield was also investigated, it was found that the oilyield increased substantially at intial time, but becomes constant at further increase in the duration of the pressing at prescribed temperature at pressure.