Performance and Emission Characteristics of a Single-Cylinder Four-Stroke Diesel Engine Fueled with Diesel–Rice Bran Methyl Ester–Isobutanol Blends

The increasing demand for energy and the depletion of fossil fuels have led to the search for alternative and renewable fuels for diesel engines. Biodiesel derived from vegetable oils and alcohol-based fuels are considered promising substitutes due to their renewable nature and lower emissions. In this study, the performance and emission characteristics of a single cylinder four-stroke diesel engine fueled with diesel blended with rice bran methyl ester biodiesel and isobutanol are investigated. Rice bran oil is converted into biodiesel through the transesterification process to produce rice bran methyl ester (RBME). The prepared biodiesel is blended with diesel and isobutanol in suitable proportions and tested in a diesel engine without any engine modification. The engine performance parameters such as brake thermal efficiency and brake specific fuel consumption are evaluated under different load conditions. Emission parameters including carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NOx), and smoke opacity are also measured. The present study focuses on the performance and emission characteristics of a single cylinder four-stroke diesel engine fueled with diesel blended with rice bran methyl ester biodiesel and isobutanol. The engine is tested under different load conditions to evaluate parameters such as brake thermal efficiency, brake specific fuel consumption, and exhaust emissions including CO, HC, NOx, and smoke opacity. The objective of this study is to analyze the suitability of rice bran biodiesel and isobutanol blends as an alternative fuel for diesel engines and to assess their impact on engine performance and environmental emissions.