Exhaust Emissions and Combustion Performances of Rapeseed Oil Monoester of Ethylene Glycol Monomethyl Ether as a Novel Biodiesel

In this paper, a novel biodiesel named rapeseed oil monoester of ethylene glycol monomethyl ether has been developed, which has one more ester group than traditional biodiesel. It was synthesized and structurally identified through FT-IR, 1H NMR analyses. Engine test results show that when atested diesel engine is fueled with this biodiesel in place of 0#diesel fuel, engine-out smoke emissions can be decreased by25.0% to 75.0%, CO emissions reduced by up to 50.0% and unburned HC emissions lessened significantly, but NOx emissions generally do not change noticeably. In the area of Combustion performances, both engine in-cylinder pressure and its changing rate with crankshaft angle are increased to some extent. Rapeseed oil monoester of ethylene glycol monomethyl ether has much higher cetane number and shorter ignition delay leading to auto-ignition 1.1°CA earlier than diesel fuel during engine operation. Due to certain amount of oxygen contained in the new biodiesel, the engine thermal efficiency was improved by 13.5% to 20.4% when fueled with the biodiesel compared with diesel fuel.