Glycerol derivatives for diesel fuel reformulation

Biofuels are an important means of progress to reduce greenhouse gases and local pollution and to diversify energy. For diesel engines, FAME (Fatty Acid Methyl Ester), coming from trans esterification of vegetable oils, have already shown their potential as fuel substitutes. Nevertheless, this trans esterification induces glycerol production as a co - product. At the same time, oxygenated compounds have been shown to have great potential for reducing diesel particulate emissions. So using glycerol as a basis to synthesize new oxygenated compounds, for diesel fuel formulation could be promising. This paper deals with the synthesis of oxygenated compounds coming from glycerol, such as acetals, ethers, or carbonates, and their evaluation as blending components in diesel fuel. The objective of this work is to evaluate their potential, in terms of pollutant emissions, with different engine technologies. Their impact on particulate emissions depends on the engine technology and the chemical structure of the glycerol derivatives. For the Euro II vehicle, the decrease in particulate emissions is up to 20% on NEDC cycle. Although the Euro III vehicle is less sensitive than the Euro II, with only 5% in volume of glycerol derivatives, up to12% of particulate reduction is possible. The impact on NOx emissions is rather low especially for the Euro III vehicle. Tests with an HCCI engine have shown that some glycerol compounds could improve the running of HCCI engine.