Nanoparticle-enhanced bio-lubricants for cleaner and more efficient diesel engine performance

Abstract

This study addresses the challenge of reducing engine emissions and improving performance by investigating the use of jojoba-derived biodiesel and bio-lubricants as sustainable substitutes for diesel and mineral oil. A comprehensive experimental evaluation was conducted on a single-cylinder, 4-stroke compression ignition engine. The baseline test utilized neat diesel with SAE 40 mineral oil, followed by tests using a 20 % blend of jojoba biodiesel. This blend was first tested with mineral oil, then with epoxidised jojoba oil as a bio-lubricant, and finally with a nano-enhanced bio-lubricant incorporating 2 % titanium dioxide (TiO₂) nanoparticles. Engine performance and emission characteristics were analyzed under varying load conditions to assess the viability of these alternatives. Parameters such as Brake Thermal Efficiency (BTE), Brake Specific Energy Consumption (BSEC), and Friction Power were evaluated. Emission outputs, including NOx, HC, CO₂ and smoke opacity, were measured using standard instrumentation. The results indicate that the use of jojoba biodiesel blends improves BTE and reduces BSEC, highlighting enhanced fuel conversion efficiency. The replacement of mineral oil with epoxidized jojoba oil as a lubricant resulted in lower frictional losses and improved thermal stability. The addition of TiO₂ nanoparticles further decreased BSEC, confirming enhanced energy efficiency and smoother engine operation. Emission levels were significantly reduced across all biodiesel-biobased lubricant combinations compared to the baseline. Overall, the study underscores the viability of jojoba oil-based fuels and lubricants as renewable and eco-friendly energy sources. These findings support the advancement of sustainable energy technologies in internal combustion engines, aligning with global efforts to reduce fossil fuel dependency and environmental impact.