Effect of kinematic viscosity variation with blended-oil biodiesel on engine performance and exhaust emission in a power tiller engine

Abstract

The optimum conditions for producing biodiesel by combining beef tallow, a waste resource with high saturated fatty acid content, and soybean oil, which has high unsaturated fatty acid content, were investigated. Furthermore, the kinematic viscosity reduction effects of biodiesel by using heating and ultrasonic irradiation were verified, and their impacts on engine performance and exhaust emissions were evaluated. The result shows that the optimum production conditions are a blend ratio of TASO3 (soybean oil to tallow blend ratio of 7:3) and a methanol to oil molar ratio of 12:1. Kinematic viscosity reduction experiment results showed that the kinematic viscosity reduction effects of ultrasonic irradiation and heating were similar, but the heating device is considered more effective because it is simpler and cheaper than the ultrasonic device. Experiment results on output performance and exhaust performance showed that the engine performance and exhaust performance of the fuel with reduced kinematic viscosity were higher than those of the untreated fuel. However, the output of biodiesel was lower than those of conventional diesel (CD) due to the low calorific value of biodiesel; the NOx and CO2 emissions of biodiesel were higher than those of CD, but the CO and HC emissions of biodiesel were lower.