Investigating and optimizing the mixture of hydrogen-biodiesel and nano-additive on emissions of the engine equipped with exhaust gas recirculation

Abstract The current research was conducted with the aim of investigating the combined effect of diesel, biodiesel, hydrogen, aluminum oxide nanoparticles (Al2O3) and Exhaust Gas Recirculation (EGR) system on diesel engine emissions and performance. Data analysis showed that with a 30% increase in biodiesel, the amounts of Hydrocarbons (HC) and Carbon Monoxide (CO) decreased by 11.7% and 14.9%, respectively. However, it reduced power and torque. Increasing the share of EGR in the intake air decreased the power and torque due to the decrease of oxygen, and by adding 30% of the exhaust gas to the intake air, it reduced the amount of HC by 3.2%. However, it caused an increase in CO. By increasing the concentration of Al2O3 from 30 ppm to 60 ppm, the amount of HC decreased by 5.4%. Further increase to 90 ppm reduced CO by 5.8% but increased nitrogen oxides (NOx) by 8%. However, the torque increased by 4.89%. Increasing hydrogen by 10% of intake air volume increased power and torque by 16%, but also increased CO by 7.19%. However, further increase of hydrogen decreased power and torque. The optimal point obtained for Al2O3, hydrogen, biodiesel and EGR compounds was 61, 10, 20 and 15% ppm, respectively.