Effect Of Camellia Sinensis Oil Methyl Ester on Engine Performance and Exhaust Emissions Under Varied Fuel Injection Pressures

Oil obtained from Camellia sinensis seeds was transesterified to produce Camellia sinensis oil methyl ester (CSOME). The experimental fuels were prepared by volumetrically blending CSOME with conventional diesel fuel, as presented in Table 1. During the experiments, the test engine was operated under full-load conditions using each fuel type, and the engine performance parameters, including torque, brake power, specific fuel consumption, and exhaust emission characteristics, were evaluated at injector pressures ranging from 175 to 200 kg/cm². The experimental results demonstrated that carbon monoxide (CO) emissions of the B50D50, B20D80, and B100 fuel blends were lower than those of neat diesel fuel (D100). In contrast, unburned hydrocarbon (HC) emissions were higher for the biodiesel-containing blends compared with D100. Carbon dioxide (CO₂) emissions increased for the B50D50, B20D80, and B100 blends, whereas oxygen (O₂) concentrations in the exhaust gases decreased relative to diesel fuel. Furthermore, nitrogen oxides (NOₓ) emissions were found to be higher for all biodiesel blends than for pure diesel fuel. Among the tested fuels, the maximum torque value of 54.570 Nm was obtained with D100 at an injector pressure of 200 kg/cm² and an engine speed of 1100 rpm. The highest brake power output, 9.556 kW, was achieved using the B20D80 blend at 1900 rpm under the same injector pressure condition. In addition, the minimum specific fuel consumption was recorded as 344.512 g/kWh for the B50D50 blend at 1400 rpm and an injector pressure of 175 kg/cm².