混配柴油凝点及溶解度参数的分子模拟研究

石化柴油中添加少量生物柴油调配混配柴油是当前研究的一个热点.分别用单组分、3组分和5组分正构烷烃构建石化柴油模拟系统,以亚油酸甲酯（ML）构建单组份生物柴油模拟系统.按2％、4％、6％、8％和10％物质的量比添加ML于石化柴油模拟系统中构建不同比例的混配柴油系统.利用分子动力学方法对各种系统的凝点区间及溶解度参数进行了模拟计算.利用热容等4个性质联合判断出各系统的模拟凝点区间,发现,随着ML的添加,系统的凝点总体呈下降趋势,说明生物柴油确具有明显的降凝效果,添加生物柴油可以使柴油的低温流动性增加.相比较而言,采用3组分正构烷烃构建石化模拟系统更为合适.通过对293 K时3组分石化柴油系统添加不同比例的ML构成的混配柴油系统的溶解度参数进行分析,得出了当添加比例为4％时两种油品的相容性最佳的结论.

Research of Mixed Biological Diesel Oil Solidifying Point and Solubility Parameters by Molecular Dynamics Simulation

The core of current study is to add a small amount of biodiesel in petrochemical diesel to make mixed diesel. In this study, it is mainly to build a petrochemical diesel simulation system by using n-alkenes of mono component, three-component and five-component, and build a one-component biodiesel simulation system by using methyl linoleum （ML）. ML is added into petrochemical simulation system re- t spectively in the proportion of 2%, 4%, 6%, 8% and 10% mol to build a mixed diesel system of differ- ent ratios. The study adopts molecular dynamics method for simulation computation of the parameter of condensation point and solubility parameters in each. It uses four properties heat capacity included, to jointly determine the parameter of simulation condensation point of each system., It is found that with the increase of ML, the condensation point decreased, which suggests that the biodiesel has obvious effect of cooling matters, and adding biodiesel will improve low - temperature-fluidity of diesel. In comparison, three-component n-alkenes are more suitable for building petrochemical simulation system. It also comes to conclusion that when added 4% of ML, the compatibility of the two kinds of oil is reaching the best by analyzing the parameter of solubility of mixed diesel system, which is combined by three-component pet- rochemical diesel system based on 293K and different proportion of ML.