Analysis on the impact of biodiesel–ethanol–diesel fuel on the performance and emissions of a diesel engine

Investigating the Effect of a Diesel–Refined Crude Palm Oil Methyl Ester–Hydrous Ethanol Blend on the Performance and Emissions of an Unmodified Direct Injection Diesel Engine

“…The NO x emission increased as the engine load increased. 74 The concentration of O 2 in the fuel is an important factor in NO x emission, and high O 2 concentrations in biodiesel increase combustion, resulting in greater NO x emissions, similar to diesel, as reported by Ramalingam and Rajendran 76 and Ghadikolaei et al 80 Additionally, the higher viscosity factor of biodiesel results in the spraying of larger fuel droplets and an ignition delay, resulting in higher NO x emissions, similar to those described by Altaie et al 81 70 and Zhang et al, 78 NO x emissions increase with the biodiesel content of the fuel blends. In particular, NO x emissions of pure biodiesel were higher than those of diesel.…”

“…However, adding ethanol to the mixture lowered the cetane number, leading in a longer ignition delay and increased NO x levels at low speeds. Conversely, at high engine speeds, the high latent heat of vaporization and low heating value of ethanol result in lower NO x formation. , Yilmaz et al and Ghadikolaei et al found a similar result, indicating that increased latent heat of alcohol vaporization is a critical factor contributing to heat absorption in the combustion chamber and the decrease in NO x formation.…”

“…High NO x emissions were observed when the concentration of biodiesel blends in diesohol was increased. According to studies by Jia et al and Zhang et al, NO x emissions increase with the biodiesel content of the fuel blends. In particular, NO x emissions of pure biodiesel were higher than those of diesel.…”

“…Because ethanol has a lower cetane number and heating value than diesel, the P b of fuel blends is lower than that of diesel at a maximum engine speed of 2300 rpm; the P b values of D40RM50E10, D30RM60E10, D20RM70E10, and D10RM80E10 were 18.39, 20.12, 24.05, and 31.46%, respectively. Jia et al 70 reported that the engine brake power of the diesel−biodiesel−ethanol blend was lower than that of diesel and decreased in proportion to the increase in biodiesel or ethanol content because the calorific value of the fuel blend was lower than that of diesel. Tripathi et al 71 reported a similar result and stated that adding ethanol to the fuel blend led to reduced cetane numbers and engine power due to a longer ignition delay.…”

“…The results of this test were mostly related to the latent heat of ethanol, carbon−carbon double bond in biodiesel, and the physical and chemical nature of oxygen in ethanol and biodiesel, which led to lower HC emissions. 70 According to Jamrozik et al, 27 a lower ethanol content decreases the viscosity and density of the mixture, resulting in better spraying and atomization, which leads to enhanced combustion and lower HC emissions. However, partially unburned ethanol, long-period combustion, a low cetane number, and a low cylinder temperature all contribute to greater HC emissions for some fuel blends.…”