INVESTIGATION OF WATER-IN-BIODIESEL EMULSION CHARACTERISTICS PRODUCED BY ULTRASONIC HOMOGENIZER

Fuel modification is the preferred technique to reduce the exhaust emission levels of
diesel engine. Various studies had proved the effectiveness of using Water-in-diesel
Emulsion (WiDE) in reducing exhaust emissions of diesel engine. Mechanical
homogenizing method is the most commonly used method in majority of researches
and studies of WiDE. Limited studies had been conducted using WiDE produced
from ultrasonic homogenizing method. The project aims to characterize and study
the exhaust emissions of Water-in-biodiesel Emulsion (WiBE) produced using
ultrasonic homogenizer through various laboratory investigations and compare the
characterization and emission data with WiBE produced using mechanical
homogenizer in previous researches.
Physical characterization tests were carried out on 24 WiBE samples produced using
an ultrasonic homogenizer, with water percentage of 9%, 12% and 15%, HLB value
of 6, 7, 8 and 9, and surfactant dosage of 5% and 10%. The tests consisted of water
droplet size, viscosity at 40°C, density at 15°C and CHNS element analysis. Seven
samples were reproduced for engine performance test and exhaust emission
measurements. The water droplets were found to be evenly distributed and generally
smaller in size compared to samples produced using mechanical homogenizer.
Samples of 10% surfactant dosage were observed to have lower SMD values
compare to 5% surfactant dosage for samples of HLB 7 and 8. The density and
viscosity values of these samples were found to be uniformly larger than WiBE
samples produced using mechanical homogenizer. All samples of 9% and 12% water
percentage had density values under the acceptable value range. Samples of HLB 6,7
and 8 had viscosity values under the acceptable viscosity values. The WiBE samples
that satisfied the optimum conditions are WiBE 13, 14, 16, 17, 19 and 20.