大豆油及其生物柴油低温流动特性研究

Cold Flow Properties of Soybean Oil and Its Biodiesel

采用燃料低温性能测定仪考察了大豆油及其生物柴油的冷滤点、凝点和运动粘度,采用偏光显微镜和示差扫描量热分析仪探讨了大豆油及其生物柴油低温下失去流动性的机理。结果表明:大豆油制成生物柴油后,运动粘度显著降低,冷滤点降低,凝点略有升高。在低温下,大豆油形成无定形粘稠玻璃状物质,粘度增大,使其失去流动性;大豆油生物柴油中的晶态物质析出,连接成网状结构,包络和吸附了处于液态的生物柴油,使其失去流动性。

Cold filter plugging point, solidifying point and viscosity of a soybean oil and soybean biodiesel were measured by a muhifunctional low temperature instrument. The solidification mechanisms were investigated by a polarized microscope and a differential scanning calorimeter. The results indicate that viscosity and cold filter plugging point of soybean biodiesel reduce considerably and solidifying point increases slightly compared with those of soybean vegetable oil. At low temperatures, the increase of viscosity and the formation of thick amorphous glass-like materials jointly impair the fluidity of soybean oil, while for soybean biodiesel, the production of a spongy waxy crystal matrix wraps up liquid biodiesel and therefore inhibits its fluidity.