Residual crude palm oil extraction from palm oil mill effluent using simple hexane liquid-liquid extraction method / Mohamad Hassrul Zainal

Palm oil mill effluent (POME) is the waste water discharged from the 3 process sterilization process, crude oil clarification process and cracked mixture separation process. POME is basically made of 95-96% water, 0.6-0.7% oil, 4-5% solids 2-4% suspended solid. The standards discharge limit set by Malaysian Department of Environment for oil and grease content in POME was only 50 mg dm-3, but POME at the mill contains up to 4,000 mg dm-3 of oil and grease. This study is focusing on To determine the optimum amount of hexane to extract residual CPO left in POME and the relation between ratio of hexane, time interval and mixing speed for hexane to extract CPO from POME. The method used in this study was liquid-liquid extraction. It is called liquid-liquid extraction because hexane liquid is use to extract oil from POME whereas the POME is also in the form of liquid. Liquid-liquid extraction is mainly affected by exposure time, mixing speed and ratio between hexane and POME. So the optimum time, mixing speed and ratio was 20 minutes, 200 rpm and ratio is 3:5 respectively. By using the optimum ratio, time and speed the amount of residual oil that can be extracted is 17.5% or 0.3gram.Based on the statistical analysis it has been found that ratio of hexane to POME and speed has a significant p-value while effect of time indicates that it was not significant.