A study on the performance and emission of diesel engine with Jatropha biodiesel and its blends at different engine load

Abstract

An experimental study has been done to examine the performance and emission of a diesel engine using different blend ratios of Jatropha oil methyl ester at different engine speeds. At each speed, the engine was operated at no load, quarter, half, three quarters, and full load for different blending ratios. The performance parameters evaluated include Brake Power (BP), Brake Mean Effective Pressure (BMEP), brake specific fuel consumption (BSFC), air to fuel ratio (AFR), excess air factor, brake thermal efficiency, volumetric efficiency and the temperature of exhaust gas whereas exhaust emissions include specific emissions of O2, CO, CO2, and NOx. Biodiesel blends result in a decrease of brake power by 30.8 %, decreases in air to fuel ratio by 18 %, decreases in brake thermal efficiency by 21 %, decreases in volumetric efficiency by 10.7 % and increases in brake specific fuel consumption by 32.18 %. Specific emission of O2, CO, and NOx increases with increasing the percentage of biodiesel in fuel blends. Specific emission of CO2 decreases with increasing the rate of biodiesel in fuel blends. The results suggest that biodiesel obtained from non-edible oil like Jatropha could be a decent substitute to diesel fuel in the diesel engine.

Performance and Emissions of a Diesel Engine Fueled with a Biofuel Extracted from Jatropha Seeds

“…For various blends, Figure 5, illustrates the brake thermal efficiency as a function of engine brake power. The thermal efficiency of Jatropha increases with engine load, with maximum efficiency at 75% loading, which is consistent with references [25]. The thermal efficiency obviously decreases as the blend increases, which may be due to the lower calorific and volatility values, as well as the higher viscosity, resulting in poor atomization and vaporization [30].…”

“…The Comparison of the current study and a number of other studies [25][26][27][28] using Jatropha biodiesel as fuel are shown in Figure 3. The brake thermal efficiency and carbon monoxide emissions are important characteristics that should be compared.…”

“…It may be because the fuel blends contained more oxygen, resulting in lower levels of air consumption. [25].…”

“…This is primarily due to the lower gas temperature in the cylinder. The higher the engine speed or load, the higher the temperature of the reacting gases inside the cylinder, resulting in lower CO specific emissions and higher CO2 specific emissions in the engine [25]. Specific carbon monoxide emissions decrease as the percentage of biodiesel fuel in the blend increase.…”

“…Because biodiesel fuel has a lower carbon to hydrogen ratio than diesel fuel, it is a low-carbon fuel. When biodiesel is burned with air, it produces less CO2 than when diesel fuel is burned [25]. At full load, pure Jatropha biodiesel emits 35% less CO2 than diesel.…”