Enhanced oil recovery from palm oil mill effluent using ultrasonication technique

Abstract

Palm oil is the planet’s most exploited vegetable oil. However, its extensive commercialization has resulted in massive waste, particularly palm oil mill effluent (POME), contributing to severe environmental pollution. POME has a high concentration of oil and grease (O&G) with the mean value of 4,340 mg/L, exceeding the standard discharge limit of 50 mg/L. Hence, the recovery of oil content in POME is crucial as it could be a key material in biodiesel production. The oil droplets in POME exist in two phases: floating in the supernatant and suspended in the solids. During the solvent extraction process, the oil adsorbed by the solid particles is not entirely recovered. Thus, ultrasonication-based process intensification is introduced. Ultrasonication can break apart the solid particles and release the oil content using the principle of sound waves, thereby it will eventually increase the yield of oil recovery from POME. Although some studies were done on oil extraction from POME, the use of ultrasonication technique to enhance the extraction of oil from POME has never been done. The current research work is to investigate the feasibility of using ultrasonication technique to enhance the oil recovery from POME and compare it to a non-ultrasonicated POME. Overall, this research discovered that using ultrasonication as a pre-treatment would improve oil recovery yield from POME by 39.17% as compared to non-ultrasonicated sample under the optimum ultrasonication conditions of 30% amplitude and 30 seconds duration.