Combustion characteristics for diesel engines with emulsified biodiesel without adding emulsifier

Emulsified biodiesel has lower NOx and Smoke emissions from diesel engines compared with biodiesel. Emulsifier is needed to produce emulsification fuel. In this study, it has been clarified that the 15 wt% water emulsified biodiesel without adding any emulsifier can be produced. From the experimental results for a DI diesel engine, the fuel without emulsifier addition has shorter ignition delay and lower CO, HC, Smoke and Aclorein emissions compared with emulsified biodiesel with adding 0.1 wt% of crude glycerin, a by-product in the transesterification of biodiesel production process, as an emulsifier. There is no significant difference in the effect of the Sauter mean diameter of emulsified water particle on emulsified biodiesel combustion and emission characteristics in the range from 30 to 170 μm. Also, by adding 3 wt% of crude glycerin to biodiesel, the ignition delay of biodiesel becomes longer and the CO, HC and Smoke emissions increase. Crude glycerin affects emulsified biodiesel combustion as a combustion deterioration substance.