Search Results (2)

Biodiesel and 2-methylfuran (MF) exhibit significant potential as alternative fuels due to advancements in their production techniques. Despite this potential, the low cetane number (CN) of biodiesel–MF (BMF) blends limits their practical use in diesel engines due to poor auto-ignition characteristics and extended ignition delays. This study addresses this issue by investigating the impact of the cetane improver 2-ethylhexyl nitrate (2-EHN) on the performance and emissions of a BMF30 blend. The blend consists of 70% biodiesel and 30% MF, with 2-EHN added at concentrations of 1% and 1.5% to enhance ignition properties. The experiments were conducted on a four-cylinder, four-stroke, direct-injection compression ignition (DICI) engine at a constant speed of 1800 rpm with brake mean effective pressures (BMEP) ranging from 0.13 to 1.13 MPa. The results showed that 2-EHN improved the CN of the BMF30 blend, leading to earlier combustion initiation and longer combustion duration. At low BMEP (0.13 MPa), 2-EHN increased the peak rate of heat release and in-cylinder pressure, whereas at higher BMEP (0.88 MPa), these parameters decreased. The key findings include a reduction in brake-specific fuel consumption (BSFC) by 5.49–7.33% and an increase in brake thermal efficiency (BTE) by 3.30–4.69%. Additionally, NOx emissions decreased by 9.4–17.48%, with the highest reduction observed at 1.5% 2-EHN. CO emissions were reduced by 45.1–85.5% and soot emissions also declined. Hydrocarbon (HC) emissions decreased by 14.56–24.90%. These findings demonstrate that adding 2-EHN to BMF30 blends enhances engine performance, reduces key emissions, and offers a promising alternative fuel for diesel engines. Full article

2-Methylfuran (2-MF) has emerged as a promising renewable alternative fuel, primarily due to its sustainable production processes and its potential to significantly reduce soot emissions. However, when blended with diesel, it presents challenges, including an increase in NOx emissions, which is attributed to the lower cetane number (CN) of the M30 blend. This study investigates the effect of adding 2-ethylhexyl nitrate (2-EHN), a cetane enhancer, to the M30 blend (30% 2-MF by volume), on combustion characteristics and exhaust emissions. Experiments were conducted using a modified four-cylinder, four-stroke, direct-injection compression ignition (DICI) engine featuring a common rail fuel injection system. The engine was evaluated under different load conditions, with brake mean effective pressure (BMEP) ranging from 0.13 to 1.13 MPa, while maintaining a constant engine speed of 1800 rpm. The incorporation of 1.5% and 2.5% 2-EHN into the M30 blend enhanced combustion performance, as indicated by a reduction in the maximum pressure rise rate, a shorter ignition delay (ID), and an extended combustion duration (CD). Furthermore, the brake-specific fuel consumption (BSFC) reduced by 2.78% and 5.7%, while the brake thermal efficiency (BTE) increased by 3.54% and 7.1%, respectively. Moreover, the inclusion of 2-EHN led to a significant reduction in Nox by 9.20–17.57%, with the most significant reduction observed at a 2.5% 2-EHN, where hydrocarbon (HC) decreased by 7.93–21.59%, and carbon monoxide (CO) reduced by 12.11–33.98% as compared to the M30 blend without 2-EHN. Although a slight increase in soot emissions was observed with higher concentrations of 2-EHN, soot levels remained significantly lower than those from pure diesel. The results indicate that the addition of 2-EHN can effectively mitigate the trade-off between NOx and soot emissions in low cetane number oxygenated fuels. Full article