Evaluation of CI Engine Performance, Emissions, and Combustion Characteristics Using Corn Biofuel Blend with Divergent Cr's and Exhaust Gas Recirculation

Abstract

This thesis investigates the potential of corn oil biodiesel as a renewable alternative fuel for diesel engines. An experimental study is conducted to enhance the engine characteristics of corn oil blended diesel through various approaches, including adjusting the compression ratio, employing different exhaust gas recirculation (EGR) rates, and incorporating Nano additives into the fuel. Preliminary examinations of corn oil methyl ester (COME) blends at 10%, 20%, and 30% reveal that the COME20 blend outperforms the others, establishing it as the preferred blend for further investigation. Subsequently, the investigation proceeds with COME20 at different load and speed conditions. The experimental results demonstrate notable improvements in engine performance. Specifically, at a compression ratio of 20:1 (CR20:1) compared to 18:1 (CR18:1), brake thermal efficiency increases by 2.72%, and brake-specific fuel consumption (BSFC) decreases by 7.8%. Furthermore, significant reductions in exhaust emissions, including carbon monoxide (17.64%), unburnt hydrocarbons (13.8%), and smoke opacity (3.5%), are observed. However, there is an increase in nitrogen oxides (NOx) emissions. In terms of exhaust gas recirculation (EGR), the addition of 6% and 12% EGR to COME20-CR20 results in reduced NOx emissions compared to diesel. Notably, the 12% EGR exhibits a greater reduction in NOx emissions but compromises engine performance to a greater extent than the 6% EGR. In conclusion, this study highlights the potential of optimizing engine design (compression ratio), control (EGR rate), and fuel reformulation (COME biodiesel blending) to facilitate the efficient utilization of COME biodiesel blended diesel fuel in compression ignition (CI) engines. The findings contribute to the advancement of renewable fuel technologies and offer insights for future developments in the field of sustainable transportation. KEYWORDS: Corn oil biodiesel, Renewable alternative fuel, BSFC (Brake-specific fuel consumption), Compression ratio, Exhaust gas recirculation (EGR), Nano additives, COME20 blend