INFLUENCE OF CARBON NANOTUBES ON BIODIESEL DERIVED FROM MANILKARA SAPOTA SEED OIL FUELLED IN DIESEL ENGINE ON PERFORMANCE AND EMISSION CHARACTERISTICS AN EXPERIMENTAL APPROACH

Fossil fuels are finite resources with limited availability. As global energy demand continues to rise, the depletion of these finite resources poses a significant challenge. Finding sustainable and renewable energy sources is crucial to meet current and future energy needs. The present study aims to improve the thermal performance and reduce the emission from the single-cylinder constant-speed stationary diesel engine fuelled using Manilkara sapota biodiesel blend with CNT as an additive at different compositions. The thermophysical properties of the biodiesel blend and biodiesel blend with nano additives are studied as these are the critical parameters for effective combustion. The thermophysical properties results revealed that the optimal concentration of Manilkara sapota seed oil is 20% as these properties are closer to the diesel fuel. The concentration of biodiesel in the diesel fuel is limited to 20%. Similarly, the concentration of functionalized single-walled carbon nanotubes (SWCNT) in biodiesel varied from 15 to 45 ppm as these particles improve the mass transfer and thermal characteristics of the fuel blends. Results showed that there is a notable improvement in the brake thermal efficiency of the engine by 15.64% by employing 30 ppm CNT in the biodiesel blend compared to the biodiesel blend without nano additive. Also, the brake-specific fuel consumption from the engine is reduced by about 10.34% by using 30 ppm of CNT as an additive in the biodiesel blend. The emission results revealed that the CO and HC emissions from the engine are drastically reduced by about 27.32 and 24.36% using 30 ppm CNT in biodiesel compared to biodiesel without additives. However, due to the complete combustion of fuel with nano additives, there is an increase in NOx emission by 30.24% using 30 ppm of CNT in the biodiesel.