Estimation of equilibrium combustion products of diesel-biodiesel fuel blends using the developed solving process for CnHm and CαHβOg fuel blends

Abstract

This study investigates the combustion products of diesel-biodiesel fuel blends by considering its chemical equilibrium state. In order to determine the equilibrium combustion products involving 10 species, a solving scheme which can be used for different fuel blends consisting of CnHm and C HO generic structures was developed. The constituted solving scheme was then applied for four different mixtures which were diesel, 20 and 50 % biodiesel additions (by volume), and 100% biodiesel. The change in mole fraction of the fuels and their blends was determined as a function of temperature, pressure and equivalence ratio. Besides, mass-based combustion product rates of CO2, CO and NO for a unity of fuel mass were also investigated for different temperatures and equivalence ratios. The results show that the addition of biodiesel to diesel fuel does not have any significant effect on the change in the mole fraction of the combustion products. However, the addition of biodiesel reduces slightly the formation of CO and NO, while CO2 shows a slightly increasing trend. In terms of mass-based combustion product rates, the biodiesel addition reduces the amount of CO2, CO and NO products because it increases the molecular weight of the fuel blends.