This study presents an investigation of some performance parameters and emissions characteristics of a six-cylinder submarine diesel engine operated on blends of biodiesel produced from waste vegetable oil (WVO). A heterogeneous catalyst was developed from waste eggshells via calcination 900 oC for 3 hrs. Waste vegetable oil was purified via hydrolysis to degum and reduce the free fatty acid of the oil. Biodiesel was produced from the purified WVO using the heterogeneous catalyst and methanol as alcohol. Nanoparticles were prepared from coconut shells via calcination at 900 °C for 5 hrs. Nanoemulsified fuel samples, B5 (5% biodiesel + 95% diesel), B10 (10% biodiesel + 90% diesel), and B20 (20% biodiesel + 80% diesel) were prepared from the produced biodiesel together with a constant weight of 5g of nanoparticles and 5wt% water. Engine tests were carried out under different load conditions (20%, 40%, 60%, 80%, and 100%) using nano-emulsified biodiesel blend and pure diesel. Performance characteristics such as brake specific fuel consumption (BSFC), brake thermal efficiency (BTE), and exhaust gas temperature (EGT) were determined. The emissions measured include CO, CO2, HC, NOx. The heterogeneous catalyst was found to have 62% CaO composition. An average yield of 90.5% was obtained from biodiesel production. The CO and HC emissions were maximum for pure diesel compared to the biodiesel blends. However, there was an increase in CO2 emissions as biodiesel content increased in the fuel blends. The NOx emissions were maximum for pure diesel, with B5 showing more NOx reduction. The results showed that all the fuel blends demonstrated more suitable qualities as a substitute fuel for a diesel engine. The blended fuels are similar to diesel performance, but B20 showed maximum BTE at full load conditions.