Study evaluates exhaust emissions of diesel fuel blends

The Department of Thermal Engineering, School of Mechanical Engineering, National Technical University of Athens (NTUA) in Greece conducted an experimental study to evaluate the performance as well as the exhaust emissions characteristics of diesel fuel blends with 8%, 16% and 24% (by volume) diethyl ether (DEE). The blends were used in a standard, experimental, single-cylinder, four-stroke, high-speed direct injection (HSDI), and ‘Hydra’ diesel engine. The researchers tested each of the fuel blends or neat diesel fuel, with each engine working at three different loads. Various aspects including fuel consumption, exhaust smoke, and regulated gas emissions like nitrogen oxides, carbon monoxide and unburned hydrocarbons were measured. The researchers then compared the differences in the performance and exhaust emission parameters of the three DEE/diesel fuel blends. The comparisons were made from the baseline operation of the diesel engines running with neat diesel fuel. Several interesting features of the combustion mechanisms were revealed when the combustion chamber and fuel injection pressure diagrams were obtained, and after the heat release rate analysis of the experimentally obtained cylinder pressure diagrams were performed. Results of the tests revealed that DEE/diesel fuel, which can be produced from biomass (bio-DEE), presents much potential for diesel engines. (July 1, 2012)