降凝剂与溶剂复配对生物柴油冷凝过程的影响

Influence of Pour-point Depressant and Solvent Mixture on Condensation Process of Biodiesel

生物柴油是生物质能的一种,其在物理性质上与石化柴油接近,但化学组成不同,且具有优良的环保特性,硫含量低,二氧化硫和硫化物的排放低、生物柴油的生物降解性高达98%,降解速率是普通柴油的2倍,可大大减轻意外泄漏时对环境的污染。该文研究了各种常用的柴油降凝剂与乙酸酯类有机溶剂的复配对生物柴油的影响。根据研究结果筛选出效果较好的样品,并采用差热分析(DSC)、低温偏光显微镜等仪器来分析其对生物柴油低温流动性的影响。降凝剂与乙酸酯复配后加入到生物柴油中,使体系在冷凝过程中析出的晶体量大大减少,并改变了晶体的成长方式,使晶体的尺寸变小,继而改变晶体的形态与分散状态,让体系的固液相变能变小,分散体系更加稳定,从而提高生物柴油在低温情况下的流动性能。该实验对生物柴油能够广泛地使用,进而替代普通柴油成为清洁能源有重要的意义,有利于改善环境现状,减少污染和保护生态环境。

Biodiesel is a kind of biomass energy,which is close to the petrochemical diesel oil in physical properties,but the chemical composition is different. With excellent environmental characteristics,low sulfur content,biodegradability,low sulfur dioxide,98% biodegradability and degradation rate 2 times faster than common diesel,biodiesel can greatly reduce the pollution to the environment when the leakage accident occurs. In this paper,the effects of the mixture of various pour-point depressants and acetic ester organic solvents on biodiesel were investigated. Based on the results,the samples with better performance were selected and their influence on the low temperature fluidity of biodiesel was analyzed by differential thermal analysis（ DSC） and low temperature polarizing microscope. When the mixture of pour-point depressants and acetic ester was added in biodiesel,the amount of crystals separated out in pour-point depressants and acetic ester was greatly reduced,the growth way of crystals was changed,the size of crystals became smaller and then the shape and distribution of crystals were changed. All of these make the transformation energy of the system smaller and the disperse system more stable,thus improving the flowing property of biodiesel in low temperature. This experiment enjoys great significance for the wide application of biodiesel by replacing common diesel to be clean energy. Biodiesel helps improve environmental status,reduce pollution and preserve the ecological environment.