Effects of adding aluminum oxide nanoparticles to butanol-diesel blends on performance, particulate matter, and emission characteristics of diesel engine

Abstract

In this study, different concentrations of Aluminum oxide (Al2O3) nanoparticles (30, 50, and 100 mg/l) were mixed with a butanol-diesel blend (B20) to examine their effects on combustion, particulate matter (PM), and emission characteristics. The samples of the B20 + Al2O3 nanoparticles were tested for different engine loads, and their thermophysical properties of viscosity, density, thermal conductivity, and flash point were measured. The blends of B20 + Al2O3 nanoparticles exhibited good stability and homogeneity when tested on the diesel engine. The results indicated that the addition of Al2O3 nanoparticles to the B20 increased the cylinder pressure and rate of heat release by 6% and 13%, respectively, compared with the B20 without Al2O3 additives. Additionally, the brake specific fuel consumption decreased by 7.3% and brake thermal efficiency increased by 4.7%, compared with those of the B20 without additives. The concentration of PM decreased by 30.5% with the fuel of B20 + Al2O3 nanoparticles under a 3.5 bar of engine load. Furthermore, the total particle mass decreased by 13.3%, and the average particle diameter increased by 9.2% for the different concentrations of nanoparticles added to the B20 under different engine loads. For both fuels, the addition of 100 mg/l of nanoparticles to the B20 decreased the CO, HC, and NOX emissions by 42.71%, 37.46%, and 12.37%, respectively. The results indicated that 100 mg/l of Al2O3 nanoparticles had the best effect on combustion characteristics, PM concentration, and gaseous emissions for different engine loads.