异构烷烃的有效碳数与物性关联研究

Study on the correlation of effective carbon number and physical properties for isoparaffins

多数异构烷烃的物性数据难以获取,且烷烃的物性与其分子结构密切相关。本文分析了异构烷烃与正构烷烃在结构上的差异,提出了用有效碳数描述异构烷烃的分子结构,体现了异构烷烃侧链对其物性的影响。并且根据有效碳数的定义,建立了油品中常见异构烷烃的结构-物性关联方法。对6类异构烷烃的物性计算结果表明,沸点、密度、折光指数的计算值与实测数据的一致性令人满意,沸点的最大绝对误差3.36K,密度的最大绝对误差0.0056g/cm3,折光指数的最大绝对误差为0.0028,计算精度优于文献方法,显示了关联方法的有效性。利用该方法,可预测异构烷烃的物性。

It is difficult to acquire the physical properties of most isoparaffins.A novel approach of property estimation for isoparaffins is introduced in this paper.Based on the the structural differences between isoparaffins and normal paraffins,the definition of effective carbon number is made.According to the effective carbon number of isoparaffins,quantitative study has been carried out on the influence of side chains to basic properties such as boiling point,density and refractive index.The structure-property correlations are constructed for several sorts of isoparaffins which are frequently detected from crude oils.The validities of the correlations are verified as the calculated properties are in good accordance with the authoritative data.The maximum absolute deviation of boiling point is 3.36 K,density is 0.0056 g/cm3,refractive index is 0.0028.The method of this paper has an advantage over the literature method.