Abstract: Ethanol diesel fuel samples with various ethanol blended ratios were prepared using distillates of 2nd and 3rd atmospheric column side cuts, catalytic cracking diesel fraction, hydrotreated diesel fraction and commercial 0# diesel fuel as base oil respectively. The mutual solubility of ethanol and diesel, physical and chemical properties, longtime stability and engine test performance were investigated. Results showed that the mutual solubility and stability of ethanol and 0# diesel fuel were excellent; the existence of water could significantly affect the stability of ethanol diesel; adding co-solvent could improve the water tolerance of ethanol diesel in some extent. The low temperature performance of diesel fuel was improved a little by adding ethanol. The copper strip corrosion test result of ethanol diesel could meet the requirement of National Standard for diesel fuel, yet its flash point and seal compatibility were dropped a bit. As compared with diesel fuel, the fuel consumption and smoke exhaust of ethanol diesel were similar to those of conventional diesel and its NOx exhaust was lower.

Key words: ethanol diesel, mutual solubility, stability, co-solvent