Sustainable Performance Assessment of a Direct Injection Diesel Engine Using Biodiesel Graphene Oxide Additive Blends Compared With Petrodiesel

Abstract

ABSTRACT The primary objective of this study is to investigate the performance, combustion characteristics, and emission behavior of a compression ignition (CI) engine fueled with a novel ternary blend enhanced by nano‐additives. The unique novelty of this article lies in deploying a dual‐purpose fuel stabilization and performance‐enhancement strategy that leverages organic chemistry and metal‐free nanotechnology, avoiding the environmental toxicity and secondary pollution common to conventional metal‐oxide additives. A base ternary fuel blend was formulated comprising 80% conventional petrodiesel, 10% sustainable non‐edible Karanja biodiesel, and 10% Lemongrass oil ( LGO ). Within this formulation, the citral‐rich LGO acts as a natural antioxidant and organic stabilizer to arrest storage degradation and phase separation. To catalytically optimize combustion, graphene oxide (GO) nanoparticles were uniformly dispersed into the ternary blend at targeted concentrations of 0, 25, and 50 ppm. Key physicochemical properties (density, viscosity, calorific value, and flash point) were systematically evaluated according to BIS standard protocols, and comprehensive engine experimental matrix runs were executed on a single‐cylinder Kirloskar CI test rig under varying mechanical loads. The experimental results demonstrated that the optimized nano‐blend ( BG5 ) significantly enhanced engine characteristics compared to conventional petrodiesel. At rated engine load, the optimized fuel formulation increased the exhaust gas temperature (EGT) by 3.2% (confirming more complete in‐cylinder heat release), successfully reduced the brake‐specific fuel consumption (BSFC) by 7.8%, and improved the overall brake thermal efficiency (BTE) by 6.1%. This investigation concludes that the synergistic combination of LGO 's natural antioxidant action and GO 's high thermal conductivity provides a highly viable, high‐performance, and eco‐compatible solution to the classic performance‐stability trade‐off of biofuels. These quantitative findings establish the proposed nano‐blend formulation as an efficient, cleaner, and strictly sustainable drop‐in alternative fuel for next‐generation CI engines without requiring any hardware modifications.