Quality of blended fuel prepared by mixing of diesel, bio-oil and emulsifier or ethanol using high speed and ultrasonic mixing

Abstract

The application of bio-oil obtained from biomass pyrolysis process with engine has limitations due to bio-oil has high viscosity and acidity, and high water content, while its heating value is low. Therefore, utilization of bio-oil in the form of blended fuel prepared by mixing with diesel is one of interesting way. However, producing of blended fuel with a good quality depends on many factors such as mixing methods, mixing conditions, type of emulsifiers and additives. Thus, the aim of this study was to investigate the quality of blended fuel prepared by mixing of diesel, bio-oil and emulsifiers or mixing of diesel, bio-oil and ethanol by using high speed and ultrasonic mixing methods. The bio-oil obtained from pyrolysis process of oil palm biomass was reduced the water content and then it was mixed with diesel at ratio of 5:90-94 % (wt.). The Span80, Tween80 or ethanol were used as emulsifiers and surfactant at the mixing ratio of 1-5 % (wt.). The prepared sample was mixed by high-speed blender and ultrasonic waves at frequency of 20 kHz. The quality of the blended fuel was determined in terms of phase separation both after mixing and during storage. The ultimate analysis, viscosity, pour point, cloud point, flash point, pH, ash content, density and higher heating value were also determined. The results showed that mixing methods, type of emulsifiers and mixing ratios had effects on the mixing quality both after mixing and during storage. Preparation of blended fuel by using ultrasonic waves provided the mixing quality better than using of high speed blender. The phase separation of blended fuel prepared by Span80 was slower than the use of Twee80 at all mixing ratios. The blended fuel that was mixed with ethanol had the mixing quality better than the use of emulsifiers. But, the blended fuel prepared with ethanol had the phase separation faster than using of emulsifiers. The determination of blended fuel properties revealed that the fuel property of blended fuel was similar to the diesel, except the color which was darker, following the color of bio-oil.