On the determination of the distillation curve of fatty acid methyl esters by gas chromatography

Abstract

Given the increased concern for environmental protection and the need for finding viable alternatives for replacing fossil fuels in internal combustion engines, the research carried out in the recent past on the use of biodiesel has increased.Out of the physico-chemical characteristics of fuels, the volatility has a great influence on the combustion process. It is therefore important to accurately obtain all the data related to the volatility of the fuels. A way to assess the fuel’s volatility is the distillation curve (DC). The simplest way to determine DC is at atmospheric pressure. However, for low volatility fuels such as biodiesel, atmospheric distillation is not indicated, therefore, using of alternative methods is needed. One method that can be used in this case is the determination of the boiling range distribution by gas chromatography (GC). The GC equipment used for this purpose is specifically designed for this aim, meaning that the determination of DC by the GC itself is a given or standard feature of the equipment. However, in many labs, such specifically designed GC equipment is not available.In this context, the paper aims at providing a GC based method for finding the boiling points of fatty acid methyl-esters (FAME) on standard FID based GC instrument for those researchers wishing to add new capabilities to their existing GC instruments. To validate the method, five different samples of pure biodiesel were analyzed, and the results obtained by applying this method were confirmed by comparison with the distillation curve obtained via vacuum distillation.