乙醇汽油(E10)蒸发性能的研究及其控制措施

STUDY ON EVAPORATION PROPERTY OF ETHANOL GASOLINE(E10)AND ITS CONTROL MEASURES

针对汽油调合组分化学组成差异大、烃类与乙醇混合溶液的非理想性,导致乙醇汽油调合过程产品质量控制困难的现状,对6种不同来源的汽油馏分进行组成分析,同时在各汽油馏分中添加体积分数为10%的乙醇制备6种汽油馏分的乙醇汽油(E10),测定汽油馏分及其E10的蒸气压和馏程,探讨乙醇的添加对汽油馏分蒸发性能的影响。结果表明:富含芳烃的重整汽油E10的蒸气压增幅最大,为17.5 kPa,富含饱和烃的加氢裂化重汽油E10、直馏汽油E10、烷基化汽油E10、异构化汽油E10的蒸气压增幅为1.5~10 kPa,富含烯烃的催化裂化汽油E10的蒸气压基本不变。6种汽油馏分E10的10%、50%馏出温度均有所降低,有利于汽油低温启动、加速性能的改善。优化乙醇汽油调合组分油的组成(尤其是控制芳烃含量)是控制乙醇汽油蒸气压不超上限的重要措施。

Because of the significant difference in the compositions of gasoline fractions from different production processes and the non-ideality of the hydrocarbon-ethanol solution,the quality control of ethanol-gasoline blending process is difficult.In this paper,the compositions of gasoline fractions from six different sources were analyzed.Six kinds of E10 gasoline with 10%ethanol were prepared.The effect of ethanol on the evaporative property of E10 gasoline was investigated based on their vapor pressure.The results showed that the E10 vapor pressure of reforming gasoline rich in aromatics increased by 17.5 kPa,the increase of vapor pressure of hydrocracking heavy gasoline E10,atmospheric gasoline E10,alkylated gasoline E10 and isomerized gasoline E10,which were rich in saturated hydrocarbons,was by 1.5—10 kPa.The change of vapor pressure of FCC gasoline E10 rich in olefins could be ignored.The distilling temperatures of 10%and 50%distillate volume of the 6 kinds of E10 were all decreased,which is beneficial to improve the low temperature starting and accelerating performance of engine.It concluded that optimizing the compositions of the ethanol gasoline(especially the content of aromatic hydrocarbons)is the key to control the vapor pressure without exceeding the upper limit.