An increase in population count and a desire to reduce environmental hazards make researchers search for fuel that can be eco-friendly and combat the setbacks of conventional fossil fuel. Chlorella emersonii is a common freshwater green algae found in India. This oil is transesterified and converted to Chlorella emersonni methyl ester (CEME) biodiesel to mainly reduce viscosity and improve a few other properties. In the experiment, blending of CEME biodiesel with diesel was done on a volume basis, and B10 (100% CEME and 90% diesel), B20 (20% CEME and 80% diesel), B30 (30% CEME and 70% diesel), and B100 (100% CEME) were prepared for testing in a stationary single-cylinder diesel engine. Test results showed that B30 exhibited better results than others with high brake thermal efficiency, fewer emissions of HC by 24%, CO by 50%, smoke by 56%, and high cylinder pressure and heat release rate (HRR). Thus, the obtained results are close to diesel.