Influence of diethyl ether (DEE) addition in ethanol-biodiesel-diesel (EBD) and methanol-biodiesel-diesel (MBD) blends in a diesel engine

- Cylinder pressure and peak pressure rise were higher for EBD-5DEE.
- Highest HRR is observed for neat EBD without additives.
- Lowest NOx and BSFC were recorded for MBD-5DEE.
- DEE addition in EBD reduces the ignition delay, EGO, PM and smoke emissions.
- DEE addition in MBD lowers the combustion duration, HC and NOx emissions.

The present work focuses on improving the performance of ternary blends (alcohol-biodiesel-diesel) by using DEE (diethyl ether) as ignition enhancer. The test fuels used are diesel, a blend of ethanol (20%)-biodiesel (40%)-diesel (40%) (denoted as EBD), blend of methanol (20%)-biodiesel (40%)-diesel (40%) (denoted as MBD), a blend of EBD with 5% Diethyl ether (denoted as EBD-5DEE), a blend of EBD with 10% Diethyl ether (denoted as EBD-10DEE) and a blend of MBD with 5% Diethyl ether (denoted as MBD-5DEE). MBD-10DEE blend was very viscous and the engine stopped working at higher engine loads. Hence, MBD-10DEE was not considered among the test fuels. Experimental results revealed that, the addition of DEE in EBD increased the combustion duration, cylinder pressure and BSFC with reduced NOx, PM and smoke emissions due to reduced ignition delay and higher latent heat evaporation. Whereas, DEE addition in MBD increased the PM, CO, CO2 and smoke emissions with lowered BSFC, cylinder pressure, heat release rate (HRR) and combustion duration. In comparison with EBD-10DEE, EBD-5DEE effectuated in higher cylinder pressure, HRR, EGT and NOx with lowered combustion duration, THC, CO2 and PM. This is due to improved fuel atomization and enhanced fuel spray characteristics. The peak HRR of EBD is highest and that of MBD-5DEE is lowest. Overall, EBD-5DEE and MBD-5DEE reflects better engine performance, combustion and emission characteristics than EBD blend.