酚类化合物对催化柴油氧化安定性的影响

对催化裂化柴油进行碱-醇抽提,抽提出催化柴油中的酚类化合物。测定抽提前后催化柴油的氧化安定性总不溶物的质量浓度由3.571mg/100mL降至1.257mg/100mL。结果表明,酚类化合物对柴油的氧化安定性有较大的影响。考察酚的类型以及酚的质量分数对催化柴油安定性的影响表明,在酚羟基的邻位上有烷基侧链的酚对柴油有抗氧化作用,而间位上有烷基侧链的酚抗氧不明显。随酚类化合物质量分数的增加,氧化安定性总不溶物的质量浓度先下降后升高,酚类化合物的质量分数在175μg/g时催化柴油安定性最好,同一结构的酚在催化柴油中既可以发生和烃类过氧化自由基结合生成稳定的化合物,也可以发生自身的缩合反应。

Effects of Phenols on Stablity of FCC Diesel Fuels

Phenol compounds were obtained from FCC diesel fuels by alkali-alcohol extraction. The testing result is that the mass concentration of YHCZ of FCC diesel fuels was decreased from 3.571 mg/100 mL to 1.257 mg/100 mL which indicates that phenol compounds has dramatic effects on the oxidation stability of diesel fuels. The effects of kinds and mass concentration of phenol compounds on oxidation stability was studied. The phenols with alkyl side chains on the ortho-position to the phenylic hydroxyl group has positive effects on anti-oxidation and the phenols with meta-position alkyl side chain has no obvious effect on anti-oxidation of FCC diesel fuels. With the mass fraction of phenol compounds increasing, the mass concentration of YHCZ of FCC diesel fuels decreases first and then increases. While the mass fraction of phenol compounds is 175 μg/g, the invariability of FCC diesel fuels is the best. The results show that the same structural phenol compounds not only can condensate between themselves, but also combine with hydrocarbon free peroxy radicals to form stable compounds.