In the process of splitting a fat or oil to produce methyl esters, glycerine is produced as a co-product in an amount equal to 10% of the esters by weight. If, as anticipated, biodiesel grows to 1 billion gallons worldwide, an extra 400,000 tonnes of glycerine would reach the market. Maintaining high value uses for the biodiesel co-product will be critical for biodiesel and oleochemical economics. Thus, in the interest of maintaining glycerine value, glycerol ethers, which are the reaction product of isobutylene and glycerine, have been suggested as components in diesel fuel. Similarly, a combination of biodiesel and glycerol ethers has been suggested as an additive to diesel fuel.
The glycerine derivative was examined for potential use as a blend component, along with biodiesel, in diesel fuel. The study objectives were to demonstrate that the glycerine derivative is suitable for use as a diesel fuel component and to perform limited emissions and performance testing of the oxygenated diesel blends. A screening methodology based on Department of Energy (DOE) work, which was reported in SAE
2001-01-3631, was used to evaluate the glycerine derivative. A DaimlerChrysler OM611 CIDI engine for light-duty vehicles was used for the fuel evaluations. The Bosch smoke number, total particulate matter (PM), total volatile fraction (TVF), NOx, CO, THC, CO2, and O2 were measured for several blends and a base fuel.
Based on total PM emissions and other considerations, this study concludes that Di-Butoxy Glycerol (DBG) is a promising candidate for blending in diesel fuel and that further investigations into heavy-duty diesel engine emissions continue.