Effect of CNG Induction on the Performance and Emission Characteristics of a DI Diesel Engine Fuelled with Biodiesel Ethanol Blends

Abstract

To reduce the car's dependence on fossil fuels and natural resources, renewable fuel (Bio Diesel) is used as fuel for diesel engines. To reduce the viscosity and improve the performance of Biodiesel, they are mixed with ethanol. Blends of 5%, 10% and 15% ethanol with biodiesels were prepared. The performance characteristics of neat biodiesel and blended fuels were compared to the reference diesel. Biodiesel performance was improved with increasing ethanol fraction. Pure biodiesel had higher NOx emissions and smoke transparency than diesel operation, but NOx was significantly reduced. A CNG detection device was installed on the engine to study performance and the emission characteristics of the engine with induced CNG. The engine was fueled at different rates of 3 lpm, 6 lpm, 9 lpm using B90E10 as injection fuel and CNG as inline fuel. From the analysis, it can be seen that a 3 lpm flow of CNG helps to reduce smoke (15%) and NOx emissions(25%) and smoke opacity (35%) for ethanol fuel. However, it showed increased HC (10-35%) and CO (5-20%) emissions compared to running on pure biodiesel at different loads. From the study, it is clear that the blend of ethanol and biodiesel up to 10% presents a better compromise between emissions and performance characteristics. Additionally, to improve the engine operation, the injection timing has been modified (11 to 23 bPMH), when using B90E10 + 3 lpm CNG as fuel.