TEPA与降凝剂复配对生物柴油离子含量的影响Effect of the combination of TEPA and pour point depressant on the ion content of biodiesel

为对生物柴油的规模化应用提供参考，以小桐子生物柴油为研究对象，利用离子色谱系统研究了5种降凝剂（平安者、秒速、易威、凡响、海龙）、抗氧化剂四乙烯五胺（TEPA）及其复配物对生物柴油离子含量的影响，并测定了加入不同添加剂生物柴油的凝点及氧化安定性。结果表明：TEPA与降凝剂复配在一定程度上降低了生物柴油的凝点，延长了生物柴油的氧化诱导期，其中抗氧化效果最好的是TEPA与易威复配；5种降凝剂添加量为0.4%时，油样中不同种类的离子含量变化趋势不同，有机酸离子含量变化较小，无机阴离子和阳离子含量降低，其中NO-3、Cl-、Br-、PO3-4、NH+4、Mg2+、Ca2+含量明显降低，5种降凝剂均使NO3 -含量降至0，降凝剂易威导致PO3-4含量降幅最大，降低4.25 mg/kg；TEPA添加量为0.05%时及TEPA与降凝剂复配使有机酸含量增加，Cl-、NO-3、PO3-4、Na+、K+、Mg2+、Ca2+含量降低，其中TEPA与秒速的复配使Mg2+含量降幅最大，降低0.87 mg/kg，使Ca2+、Na+、K+、NO-3含量降低100%。综上，TEPA与降凝剂复配降低了生物柴油的阴离子含量和碱及碱土金属离子含量，同时也降低了生物柴油的凝点，提升了生物柴油的氧化安定性。 In order to provide reference for the large-scale application of biodiesel, taking Jatropha biodiesel as the research object, the effects of five pour point depressants (Ping′anzhe, Miaosu, Yiwei, Fanxiang, Hailong), antioxidant TEPA and their complex on the ion content of biodiesel were studied by using an ion chromatography system. The pour point and oxidation stability of biodiesel with different additives were also measured. The results showed that the combination of pour point depressants with TEPA reduced the pour point and improved the oxidation induction period of biodiesel to a certain extent, among which the best antioxidant effect was the combination of TEPA and Yiwei. When the five kinds of pour point depressants were added at 0.4%, the change trend of different kinds of ion contents in the biodiesel samples were different, the content of organic acid ions changed less, the content of inorganic anions and cations decreased, NO-3, Cl-, Br -, PO3-4, NH+4, Mg2+, Ca2+ contents were markedly reduced. Among them, all the five kinds of pour point depressants reduced the NO-3 content to 0. The pour point depressant Yiwei led to the largest reduction in PO3-4 content by 4.25 mg/kg. When the dosage of TEPA was 0.05%, and the combination of TEPA and pour point depressant resulted in an increase in organic acid content and a reduction in Cl-, NO-3, PO3-4, Na+，K+, Mg2+, Ca2+ contents. The combination of TEPA and Miaosu resulted in the largest decrease of 0.87 mg/kg of Mg2+ and reduced the Ca2+, Na+, K+ and NO-3 contents by 100%. In summary, the combination of TEPA and pour point depressants can reduce the anion, alkali metal ion and alkaline earth metal ion contents of biodiesel, and also reduce the pour point of biodiesel, and improve the oxidation stability of biodiesel.