Abstract: Because of the significant difference in the compositions of gasoline fractions from different production processes and the non-ideality of the hydrocarbon-ethanol solution, the quality control of ethanol-gasoline blending process is difficult. In this paper, the compositions of gasoline fractions from six different sources were analyzed. Six kinds of E10 gasoline with 10% ethanol were prepared. The effect of ethanol on the evaporative property of E10 gasoline was investigated based on their vapor pressure. The results showed that the E10 vapor pressure of reforming gasoline rich in aromatics increased by 17.5 kPa, the increase of vapor pressure of hydrocracking heavy gasoline E10, atmospheric gasoline E10, alkylated gasoline E10 and isomerized gasoline E10, which were rich in saturated hydrocarbons, was by 1.5-10 kPa. The change of vapor pressure of FCC gasoline E10 rich in olefins could be ignored. The distilling temperatures of 10% and 50% distillate volume of the 6 kinds of E10 were all decreased, which is beneficial to improve the low temperature starting and accelerating performance of engine. It concluded that optimizing the compositions of the ethanol gasoline (especially the content of aromatic hydrocarbons) is the key to control the vapor pressure without exceeding the upper limit.

Key words: ethanol gasoline, blending, vapor pressure, boiling range