Diesel oil with bioethanol as a fuel for compression-ignition engines

The research focussed on working out the stable, homogenous ethanol-diesel oil fuel containing co-solvent, with properties close to these required for commercial diesel oil. The influence of bioethanol content on properties of bioethanol-diesel oil blends was examined. Two different diesel oils were tested: diesel oil containing 7% V/V of fatty acids methyl esters and diesel oil without esters. Bioethanol content ranged from 5% V/V to 30% V/V. Because of the poor miscibility, the action of different alcoholic co-solvents at 5% and 10% volume concentrations was estimated. The physical stability of blends was tested visually and with the use of multiple light scattering technique. Admixture of bioethanol deteriorated physicochemical and functional properties of the fuels, therefore some additives improving these properties were investigated. On the base of the research results two formulas of fuels containing diesel oil (without and with 7% V/V of fatty acids methyl esters), 15% V/V bioethanol, 5% V/V co-solvent (2-ethyl-1-hexanol) and appropriate additives were prepared and tested on chassis dynamometer with Ford Escort 1.8 TD. The effect of tested fuels on engine performance and emissions was determined. Experimental results showed the engine power and torque loss over 10% in case of diesel-bioethanol-co-solvent mixture. Presence of fatty acids methyl esters caused further deterioration of these parameters and had a negative influence on engine running. Moreover, esters contributed to an increase in hydrocarbons, carbon monoxide emissions in comparison with diesel oil. The only advantage of this fuel was reduction of particulate matters emission. The fuel without fatty acids methyl esters also reduced emission of particulate matters while emissions of other tested harmful substances were at the same level as for diesel oil.