Environmental and performance impacts of 2-ethylhexyl nitrate and ethanol in diesel blends: A comprehensive study.

This article investigates the performance and emissions of a compression ignition (CI) engine fueled with ethanol-diesel blends enhanced by 2-ethylhexyl nitrate (2-EHN) as a cetane improver. Three fuel blends—E20 (20% ethanol, 80% diesel), E20A (20% ethanol, 0.1% 2-EHN, 79.9% diesel), and E20B (20% ethanol, 0.2% 2-EHN, 79.8% diesel)—were tested at a fixed compression ratio of 16.5 under varying load conditions, with results compared to pure petroleum diesel. The study found that E20B achieved higher brake thermal efficiency and indicated power at full load than diesel, but blends containing 2-EHN (E20A and E20B) exhibited increased emissions of hydrocarbons (HC), carbon dioxide (CO2), and nitrogen oxides (NOx) compared to diesel and E20. While ethanol blends reduced carbon monoxide (CO) emissions relative to diesel, the addition of 2-EHN negatively affected combustion characteristics and oxidative stability, indicating a need for further optimization to balance performance gains with emission control. The findings highlight the potential of ethanol-diesel blends as renewable alternatives but caution that cetane improvers like 2-EHN require careful evaluation to ensure sustainable engine operation.