The role of nanoparticles and nanofluid additives for biodiesel has gained consistent position in the current trend as they contribute to increase the performance of the engine with lower emission. In addition, additives also help to increase the engine reliability and lifespan. In this work, the effects of canola biodiesel blends of 20% proportions with diesel were investigated at 100% of engine load. The fuel is tested in a multi-cylinder water-cooled direct ignition (DI) engine. There are numerous notable works on nanofluid; however, the addition of TiO₂ nanoparticle as additive to produce canola biodiesel fuel is very limited. With the addition of the TiO₂ nanoparticle on Canola biodiesel blend in the DI engine, the exhaust property of gases such as CO, HC and NO_X is reduced. Furthermore, the combustion characteristics of the engine are improved. The canola biodiesel blends also resulted in lower NO_x emission as well as low smoke.

In this study, the corn blend biodiesel was mixed with titanium dioxide and Zinc oxide along with pentanol to examine their positive effects on a diesel engine. Five percent of ZnO and 5% of TiO₂ are added to the corn vegetable oil methyl ester to increase the efficiency of the engine. In addition to the nanoparticles, 2% of pentanol and 1% of nonionic surfactants Span80 are mixed with corn oil. The test fuels are Diesel, CVOME, CVOMEZ50, CVOMEZ100, CVOMET50, and CVOMET100. The properties like density, viscosity, cetane number, pour point, cloud point, calorific value are positively affected due to the addition of nanoparticles in the biodiesel blends. All fuels are tested in a water-cooled diesel engine with the advanced timing of 23°bTDC. The emission like CO, HC, and NOx are dropped 26%, 37%, and 19%, respectively, due to the addition of ZnO and TiO₂. The emission is reduced owing to the high oxygen content in the biodiesel blends compared to diesel. Further 10% reduction is witnessed in soot compared to diesel.

In this present study, the compression ignition engine was designed to run on CIME (Calophyllum inophyllum methyl ester) biodiesel with nanoparticles. The TiO₂ nanoparticle is added to the biodiesel in the form of nanofluid at concentration levels of 100 ppm whereas ethanox is added at levels of 100, 200 and 500 ppm. The nanoparticle and the ethanox are dispersed by the ultrasonication process. The addition of nanofluid reduces the particulate emission like nitrogen oxide (NO_x) at 100% load. The efficiency is better and emission is reduced owing to the influence of explosion of water molecules present in the biodiesel. We found ethanox to be a superlative nanofluid to reduce the emission of toxic gas at appreciable levels. We have witnessed a 20% reduction in emission of NO_x and 10% reduction of other particulate emission. In addition, the exit geometry of exhaust is modified from a circular shape to an elliptical one and the consequence of the geometry is calculated.