Combustion and emission characteristics of a light duty diesel engine fueled with hydro-processed renewable diesel

Bio-fuels are being used in an internal combustion engine for curbing regulated emissions, green house gas (GHG) and as a key to address energy security issues. Hydro-processed renewable diesel (HRD) is perceived as one of the potential drop-in alternative fuels for compression ignition (CI) engine as its cetane number is higher than petro-diesel. Combustion analysis of a single cylinder CI engine fueled with HRD and petro-diesel were compared and correlated with emissions characteristics. Soot morphology of PM emissions of the engine fueled with diesel and HRD were also analysed using a high resolution transmission electron microscope (HR-TEM). The HRD fueled engine showed longer combustion duration; smaller in-cylinder pressure and heat release rate (HRR) peak than diesel. Particle sizes of soot particles collected from the exhaust of HRD fueled engine were significantly smaller than diesel particles. Nitrogen oxides (NOx), particulate matter (PM) and carbon dioxide (CO2) emissions of the engine fueled with HRD showed substantial reductions as compared to diesel. Hence, HRD fuel is considered as a promising alternative drop-in fuel for CI engine as it is offering a solution to the problem of NOx-PM trade-off associated with diesel engine.