Clod Flow Properties And Oxidation Stability Of Palm Oil Methyl Ester

Biodiesel is a renewable and environmentally friendly energy, which is a pseudo binary solution composed of saturated fatty acid methyl ester (SFAME) and unsaturated fatty acid methyl ester (UFAME). However, the SFAME is prone to crystallization and gel in low temperature, resulting in poor engine start performance and may lead to clogged filters and lines. The UFAME contains a large number of unstable double bond, resulting in biodiesel more easily to oxidize and corrode diesel engine, line blocking. Therefore, it is necessary to study and improve the low temperature fluidity and oxidation stability of biodiesel.On the one hand, the kinematic viscosity of PME1,0# diesel oil (OPD) and-10# diesel oil (-10PD) rise with the temperature decreasing. Kinematic viscosity of PME1 changes the fastest with temperature decreasing. The kinematic viscosity of PME1 is 4.91mm2/s in 40℃, which is in accordance with the requirements of 20828-2007 GB/T. But the kinematic viscosity of PME1 has a sudden increase due to low temperature crystallization. In terms of crystalization, with the increasing of the cooling rate, ester crystals gradually occupy more space and their structures become more complex and ester crystals turn to staggered aggregation state from a single discontinuous state.On the other hand, the induction period of PME is 7.26h, in accordance with the standard of the induction period not less than 6h. The swelling degree of nitrile rubber (NBR) is worse than fluorine rubber (FKM) both in biodiesel and petroleum diesel. The corrosion of copper is worse than any other metals in PME. PME has little influence on stainless steel, cast iron and aluminum alloy, which even can be negligible.Improving results show that:(1)Three low-temperature flow improver (CFI),Flow Fit, Flow Fit K, T818,can improve low-temperature fluidity performance of PME and its blending fuel. And all this three CFI perform better in low blending ratio. T818 performs the best in low blending ratio while Flow Fit K performs the best in high blending ratio. (2) About the blending fuel effect on swelling property of rubber, the swelling property of rubber is improved in low blending ratio, while the swelling property of rubber becomes worse in high blending ratio. The anti swelling property of FKM is better than that of NBR in blending fuel. (3) The sort of metal corrosion degree in PME and its blending fuel is:copper>Aluminum Alloy>stainless steel. The metal corrosion is improved in low blending ratio blending fuel while the improvement is not obvious in high blending ratio blending fuel and the corrosion of copper and iron even become worse.