| The chemical composition of waste oil biodiesel (WME) was analyzed by GC-MS,and the low-temperature fluidity of WME was studied by low temperature differential scanning calorimetry and cold filter plugging point (CFPP) tester. Three approaches for reducing CFPP of WME were investigated including crystallization fractionation, blending with -10PD and adding cold flow improvers (Flow Fit, Flow Fit K and T818). The results showed that WME was mainly composed of fatty acid methyl esters with 14-22 of even number carbon atoms, in which the contents of saturated and unsaturated fatty acid methyl esters were 31.04% and 64.51%, respectively. The initial crystallization precipitation temperature and CFPP of WME were 1.1℃ and 3℃, respectively. Blending with-10PD, the CFPP of B20-B30 decreased to -12℃. The CFPPs of WME, B80, B60, B40, B20, B10 and B5 added with 0.1% of Flow Fit K decreased from 3, -1, -5, -9, -12, -9，-8℃ to -1, -4, -10, -17, -24, -24,-26℃, respectively. |
