Performance and Emission Characteristics Evaluation of Graphene Nanoplatelets (GNP) Additives-Based Soybean and Diesel Fuel for a Compression Ignition Engine Under Varying Loads

The growing concern over the scarcity of fossil fuels and global warming has led researchers to explore alternative fuel sources for automobiles. In this study, different blends of soybean biofuels (B20, B30, and B40) and diesel were prepared with and without the addition of graphene nanoplatelet nanoparticles (GNPs). The GNPs were added in weights of 50, 75, and 100 ppm to the soybean oil and diesel blends, resulting in B20GNP50, B20GNP75, B20GNP100, and similar blends for B30 and B40. The performance test was conducted on a compression ignition diesel engine at 1500 rpm, 18:1 compression ratio, and loads of 25%, 50%, 75%, and 100% for both the soybean oil and diesel blends with and without GNP. The highest brake thermal efficiency (43.27% and 27.49%) is achieved for the D100GNP75 and B20GNP75 blends at full load, while the lowest brake-specific fuel consumption is observed for the B20GNP75 and D100GNP100 blends at 50% and 75% loads, compared to pure diesel. An AVL gas analyzer demonstrated that biodiesel blends have lower emissions than pure diesel. The improved engine performance and reduced emissions were attributed to the combined action of oxygen at higher temperatures in the combustion chamber and the thermal characteristics of GNP.