The Effect of Mixing Light Phase Decanter with Crude Oil from The Crude Oil Tank (COT) on CPO Quality

Abstract

To improve the productivity of palm oil mills, maximizing oil recovery and minimizing losses are crucial efforts. One applicable approach is optimizing the mixing of the light phase discharged from the decanter with crude oil from the crude oil tank in the continuous settling tank. This study aimed to analyze the effect of the light phase on the final quality of the produced oil and to determine the optimal mixing ratio that yields the best oil quality. Experiments were conducted with four mixing variations between crude oil and light phase: 90%:10%, 80%:20%, 70%:30%, and 60%:40%. After mixing, laboratory analyses were performed to determine the oil content, free fatty acid (FFA) level, moisture content, and impurities of the resulting oil. The results showed that higher proportions of light phase in the mixture led to increased oil content. The FFA level initially decreased to a minimum at 23.8% light phase due to the dilution effect of crude oil by the light phase, which had higher oil content, but then increased at higher proportions because of the higher FFA contribution from the light phase and potential hydrolysis reactions. Moisture and impurity levels from the light phase did not significantly affect the quality of the mixed oil because their differences compared to crude oil were relatively small. The optimal composition was achieved at 23.8% light phase, yielding 65.07% oil content, 2.0367% FFA, 0.367% moisture, and 0.0189% impurities. These findings indicate that an appropriate mixing strategy can improve oil utilization efficiency and reduce losses, thus supporting productivity enhancement and the sustainability of the palm oil industry without compromising CPO quality standards.