Effect of biodiesels blending on their low-temperature fluidity

In order to know the influence of the composition of fatty acid methyl ester (FAME) on the low-temperature fluidity of biodiesel, and to find the way to improve it, the soybean oil methyl ester, peanut oil methyl ester and tallow oil methyl ester were synthesized from soybean oil, peanut oil and tallow oil. Their FAME composition and low-temperature fluidity have been determined. The results show that saturated long chain FAMEs are the main reason to influence the fluidity of biodiesel. The fluidity of biodiesel blends suggests that mixing FAMEs from different sources would decrease its pour point（PP） and cold filter plugging point （CFPP）. The improvement of fluidity by blending is greater than that of adding fluidity improver into high-PP biodiesels. Furthermore, the mechanism of crystallization of FAME was analyzed by observation from polarized light microscope.