Characteristics of Residual Oil Extracted from Palm Oil Mill Effluent (POME)

Abstract

Malaysia produces approximately 10 million tons of palm oil mill effluent (POME) annually. This effluent is also called oily wastewater due to its oil and grease content of approximately 0.6-0.7%. This study obtained a residual oil yield of 0.7%v of raw POME by extracting the residual oil from the palm oil mill effluent via a solvent extraction process. The extracted residual oil has been analyzed to determine its physical, chemical and fuel properties. The residual oil had the following characteristics: free fatty acid content, 7.756%; density, 0.907 g/cm ; viscosity, 43 cSt; acid value, 19.986; saponification value, 147.263 mg KOH/g oil; 3 unsaponifiable matter, 1.033%w; moisture content, 2.359%; carotene content, 407.895 ppm; and a similar fatty acid composition to commercial palm oil. The similarity of the characteristics of the residual oil to those of commercial oil and jatropha oil indicate the possibility of using the residual oil as feedstock in biodiesel production.