Combustion and Emission Characteristics of CI Engine Fueled with Water-Extracted Fusel-Biodiesel-Diesel Blends

Abstract

This study investigates the effects of water-reduced fusel oil blended with biodiesel and diesel on the emission and combustion characteristics of a single-cylinder compression ignition (CI) engine. Five fuel blends were tested: F10B20, F20B30, F10B30, F30B20, and F30B30, representing varying proportions of fusel oil (10–30%), biodiesel (20–30%), and diesel (40–70%). The engine operated at a constant speed of 1800 rpm under four load conditions (25%, 50%, 75%, and 100%). Results showed that reducing water content in fusel oil from 13.5% to 6.5% led to a 7.9% increase in carbon content and a 13% rise in heating value, while oxygen content decreased by 50%. Compared to pure diesel, all fusel-biodiesel blends exhibited CO and CO₂ emissions reductions across all engine loads. Brake power slightly increased with fuel-based blends, while brake-specific fuel consumption (BSFC) also increased following water extraction. Interestingly, although thermal properties improved after water reduction, NOₓ emissions tended to rise, highlighting a trade-off between improved combustion and regulated emissions. The study confirms that water-extracted fusel oil can enhance combustion efficiency and partially reduce harmful emissions, offering a viable pathway for alternative fuel development in diesel engines.