大豆油生物柴油低温流动改进剂研究

A STUDY OF COLD FLOW IMPROVERS FOR SOYBEAN BIODIESEL FUEL

采用多功能低温性能测定仪和旋转粘度计考察烯烃-醋酸乙烯酯聚合物(VAE)、聚甲基丙烯酸酯(PMA)和乙烯醋酸乙烯共聚物(PFV)三种低温流动改进剂对大豆油生物柴油低温流动特性及粘温特性的影响,采用偏光显微镜研究加剂前后生物柴油的低温晶态特征。结果表明,不同的低温流动改进剂对改善大豆油生物柴油低温流动性的效果不同,其中VAE可明显降低生物柴油的凝点和冷滤点。低温下,生物柴油表观粘度急剧增大,且形成三维网状结晶使生物柴油失去流动性,低温流动改进剂通过减缓生物柴油表观粘度的增大以及阻止网状结晶的形成,改善了生物柴油的低温流动性。

The influences of three cold flow improvers, polymer of vinyl acetate-ethylene （VAE）, polymethacrylate（PMA）and polymer of ethylene-vinylacetate（PEV）, on the cold flow properties and viscosity-temperature characteristics of a soybean bio-diesel fuel were studied using a lowtemperature flow tester and a rotatory viscometer. The crystal features of the bio-diesel fuel prior and post to adding improver at low temperature were investigated by a polarized microscope. Test results indicated that the cold flow improving performance of these three improvers was varied;VAE was the best one among them,which could reduce the cold filter plugging point and freezing point of soybean biodiesel fuel significantly. At low temperature the apparent viscosity of bio diesel fuel increased sharply and the formation of 3-dimensional wax crystal network made the fuel even lose fluidity. Adding VAE could suppress the formation of wax crystal network and prolong the increase of apparent viscosity, thus the cold flow properties of bio-diesel fuel was improved.