Fractionation and Characterization of Insolubles Formed in Palm Oil Biodiesel

Abstract

During the last decade, biodiesel has emerged as a promising alternative to diesel. However, the sedimentation of some insoluble material in pure biodiesel has become a concern for its producers. This material easily drops out of solution, settles on the bottom of biodiesel storage tanks and forms deposits on vehicle fuel filters. In this work, the insoluble material that forms in Colombian palm oil biodiesel was characterized for the first time. Non-expensive and easy to use Thin Layer Chromatography and Fourier Transform Infrared Spectroscopy were used as analytical techniques. The insoluble material was found not to be composed by free steryl glucosides exclusively. Acylated steryl glucosides appeared to be part of the insoluble material as well. This finding should lead to rethink the strategies that have been developed to prevent the formation of haze in biodiesel so far, as they have been mainly focused on the removal of free steryl glucosides from biodiesel.