Optimizing Performance and Reducing NOx Emissions: Quaternary and Ternary Green Blends with Carbon Nanotubes in a CRDI Engine

Abstract

This research compares the efficacy of green-synthesized carbon nanotubes in a ternary fuel blend (20% Chlorella vulgaris microalgae biodiesel, 20% bioethanol, and 60% diesel) and an innovative quaternary blend (diesel 60–70%, cottonseed oil 5%, Mahua biodiesel 15–20%, and n-butanol 15–20%) in a CRDI diesel engine. The ternary blend, with 100ppm carbon nanotubes, demonstrates improved performance, yielding a 9% enhance in brake thermal efficiency, an 11.76% decrease in brake specific fuel consumption, and a 12.79% decrease in brake specific energy consumption contrast to diesel. However, it exhibits a 13.42% increase in nitrogen oxides (NOx) and a 23.84% rise in heat release rate (HRR). On the other hand, the quaternary blend, particularly QB3-QB4, showcases enhanced efficiency with an 8% rise in BTE, a 29% decrease in specific energy consumption, and controlled combustion, resulting in a 14% reduction in the rate of pressure rise. QB3-QB4 also demonstrates a 10% decrease in NOx emissions and a 2% declined in smoke, although with a marginal increase in hydrocarbon (HC) emissions. Overall, these findings offer valuable insights into alternative fuel formulations, considering both ternary and quaternary blends, for optimizing engine performance and reducing fossil fuel dependency.