Energy, exergy analysis, and sustainability assessment of CI engine performance using graphene oxide and n-Butanol, DEE fuel additives blended with biodiesel-diesel fuel blend

The biodiesel-diesel blends are very popular at low mixing ratios in diesel engines which alleviates emissions and manages fossil fuel deficit in the future. However, the deterioration in performance, combustion parameters, and NOx emissions limit the usage of biodiesel-diesel fuel samples on diesel engines. Hence, the current study aims to determine the collective effect of various additives including nano and alcohols in 20% of biodiesel-80% of diesel blend (B20) on overall engine performance. B20 blend is prepared as a base fuel, and the surface-modified graphene oxide (GO) nanoparticles (at 50 ppm dosage) are added to the B20 blend (B20GO50) using ultrasonication. The optimum ratio of QPAN80 to GO nanoparticles (1:1 ratio) in the B20 blend avoids agglomeration. Moreover, 10 vol% of alcohols (n-butanol and diethyl ether (DEE) were added to the B20GO50 blend (B20GO50 + Bu10%, and B20GO50 + DEE10%). The Brake Thermal Efficiency (BTE), Cylinder Pressure (CP), and Heat Release Rate (HRR) were found to be enhanced by 4.91, 8.1, and 3.8% at maximum Brake Power (BP). In contrast, Brake Specific Fuel Consumption (BSFC), Combustion Duration (CD), and Ignition Delay (ID) were reduced by 15.15, 9.3, and 20.5% respectively. Whereas, emission parameters such as Hydrocarbons (HC), Carbon monoxide (CO), and Nitrogen Oxide (NOx) are lowered by 28, 17.4, and 7%, respectively, for the B20GO50 + DEE10% sample. Nevertheless, the fuel exergy rate decreased (by 6.3, 13.6, and 14.7%) but, exergy efficiency and sustainability index improved (10.7, 7.14, and 14.2% and 1.2, 5.03, and 6.28% ) for B20GO50, B20G50 + Bu10%, and B20G50 + DEE10% blends than B20 blend.