Glycerin for new biodiesel formulation

Abstract

Biofuels are an important way of progress for limiting greenhouse gas emissions, improving air quality and finding new energetic resources. For diesel engines, FAE (Fatty Acid Ester), coming from transesterification of vegetable oils, have shown their potentials as fuel substitutes. Nevertheless, this transesterification induces the production of glycerin (or glycerol) as fatal co-product. Finding an outlet to this glycerol is fundamental for the FAE network. In the same time, oxygenated compounds have been shown to have great potential for the reduction of diesel particulate emissions. Transforming glycerol into new oxygenated compounds, which could be formulated with diesel fuel, would be a very promising way. Different oxygenates derived from glycerol, such as acetals, ethers and carbonates, have been synthesized and evaluated as blending components for Diesel fuel. Our objective was to evaluate their potential, compared with RME (Rapseed Methyl Ester) blends in term of pollutant emissions with different new engine technologies and to select the most promising of them. GTBE (Glycerol Ter Butyl Ether) was the most interesting compound and it was formulated with biodiesel with the respect of the physicochemical criteria required by EN14214 standard. This new biofuel (92.5% RME + 7.5% GTBE + 1000 ppm pro cetane) was incorporated in diesel fuel (5% vol.) and compared with a mixture containing 5% RME. After various tests carried out on vehicle and engine, focusing on pollutant emissions and possible fouling problems, it is possible to conclude that this new biodiesel does not present any technical disadvantage. The decision to use this glycerol derivatives in diesel fuel formulation will thus be controlled by economical criteria. Copyright © 2008, Institut français du pétrole.