The study on the emissions of a direct injection diesel engine fuelled with methanol/biodiesel blends

Engine experiments were conducted on an 186FA diesel engine fueled with biodiesel and methanol/biodiesel blends, the formation of diesel engine pollutants was analyzed from the perspective of the methanol biodiesel blended fuel properties and chemical kinetics. Experimental results indicate that, compared with pure biodiesel, Pe=1.57 kW, biodiesel blended with 5% could lend to an increase of 279.1% in CO emission and an increase of 96.3% in HC emission. Increasing the proportion of methanol in the blends, NOx emission decreased. The NOx emissions reduction 42.7% using BM15 at full load rated speed. The exhaust smoke was almost the same at low load and not more than 0.1 BSU. At high load, the exhaust smoke decreased 51.2% using BM15. Mixed fuel spray characteristics and fuel properties of the dual role of lead Zeldovich mechanism slowed down the whole chain reaction. In the process of burning, more OH free radical is generated and reacts with the soot precursor acetylene (C₂H₂), which suppresses the formation of soot, and leads to a decrease in smoke emissions.