Recent environmental concerns raise fuel prices; hence we need the alternative petroleum source product. Currently, biodiesel is commercially produced from jatropha, cotton seeds, pongamia, mustard, chlorella emersonii (CE) seeds poses operational problems due to some of the lower calorific values, physical and chemical operation, and durability issues due to lower calorific value. In the current investigation, CE oil is adopted to generate CE Methyl Ester (CEME), while higher alcohol butanol is used. The performance of single-cylinder C.I engine at a steady speed of 1500 rpm using various blends of B1 (100% CE bio-fuel), B2 (80% volume of biodiesel and 20% volume of butanol), B3 (80% vol of biodiesel, 10% volume butanol, and 10% volume of distilled water) and diesel. This engine output, such as brake-specific fuel consumption (BSFC), brake thermal efficiency (BTE), and exhaust emission characteristics such as carbon monoxide (CO), carbon dioxide (CO2), and hydrocarbon (HC) was measured for different load conditions. Also, the smoke opacity, exhaust gas temperature (EGT), cylinder pressure, ignition delay (ID), and heat release rate (HRR) were measured. The findings were positive for the efficient usage of biodiesel with the introduction of butanol and offset a portion of the rising energy demand properties.