Separation and purification of bio-diesel : A review

Abstract

Bio-diesel-a biodegradable, sustainable and clean energy, has received growing interest especially in recent years, chiefly on account of development in biodiesel fuel and serious ecological pressures nowadays. In the production process of biodiesel from biomass, separation and purification is a critical technology. Conventional technologies utilized for separation such as gravitational settling, decantation, filtration and biodiesel purification have been proven to be inefficient, energy consumptive, and less cost effective as well. The involvement of membrane reactor and separative membrane shows huge promise for separation and purification of biodiesel. Hence, membrane technology needs to be explored and exploited to overcome these difficulties usually encountered in the separation and purification of biodiesel. In this paper both conventional and most recently membrane technologies used in refining biodiesel have been critically reviewed. The effects of catalysts, free fatty acids, water content and oil to methanol ratios on the purity and quality of biodiesel are also examined.