Synergistic formulations of jojoba methyl ester biodiesel blends and jojoba lubricant for enhanced performance and emission mitigation in biodiesel engines

The study investigates the integration of bio-based fuels and lubricants in diesel engines to enhance performance and reduce emissions, addressing global environmental challenges and sustainable energy needs. Baseline tests with conventional diesel and SAE 40 mineral oil were used for comparison. Experiments were conducted with jojoba methyl ester biodiesel blends (20% and 30%) combined with both mineral and jojoba bio-lubricants. The results indicate that jojoba bio-lubricant improves engine performance over mineral oil. The 20% biodiesel with jojoba lubricant achieved the highest brake thermal efficiency (33.4%) and lowest brake specific energy consumption (14.7 MJ/kWh), showing improvements of 1.1% and 2.7% compared to diesel–mineral oil operation. While NOx emissions increased with biodiesel–mineral oil blends, replacing the lubricant with jojoba oil reduced NOx by 11.2% (20% blend) and 10.1% (30% blend). The 20% biodiesel–jojoba lubricant combination lowered overall emissions by ∼10% compared to the same fuel with mineral oil. Further, the 30% biodiesel–jojoba lubricant blend achieved maximum reductions in smoke (16%), unburnt hydrocarbons (14%), and CO (42%) compared to diesel with mineral oil. These improvements are attributed to better compatibility between biodiesel and jojoba lubricant, enhanced combustion, and reduced frictional losses. Overall, the findings demonstrate the potential of jojoba-based fuels and lubricants to improve performance while reducing harmful emissions. The work underscores the viability of biomass-derived alternatives for diesel engines, supporting cleaner energy pathways and contributing to global sustainability goals.