Abstract: Effect of a series of acetate ester co-solvents on the phase stability of methanol–straight-run (SR) gasoline blends was studied by testing the phase separate temperature of these blends. Results show that methyl acetate, ethyl acetate, propyl acetate, butyl acetate, amyl acetate and isoamyl acetate all have positive effect on the phase stability of a series of methanol–SR gasoline blends with various blending ratios (M15, M30, M50 and M65) in the temperature range of -27 ℃ to 36 ℃, and this effect enhances with the increase of carbon number in the oxyalkyl of acetate ester. The effect of alkoxy isomerization on the phase stability of methanol–SR gasoline blends was studied by comparing the phase stabilities of these blends containing butyl acetate, amyl acetate and isoamyl acetate respectively.

Key words: methanol-straight-run gasoline, phase stability, acetate ester, solubilizing effect