A Continuous Model for C7+ Fraction Characterization of Petroleum Fluids

In this paper, based on a two-parameter distribution model, a method is presented to predict complete property distributions for molecular weight, boiling point, specific gravity, and refractive index of a C7+ fraction. Only three mixture bulk properties such as molecular weight, specific gravity, and refractive index are needed for this technique. If a distillation (TBP) analysis for the fraction is available, then only two bulk properties such as molecular weight and specific gravity (or refractive index) are sufficient. Predicted distributions for various properties are compared with experimental data of some 48 crude samples. The method is also applied for flash vaporization of a Russian crude oil, and predicted distributions for feed, vapor, and liquid streams are compared with actual data. Splitting and lumping schemes of petroleum fractions using the proposed distribution model are also presented by two different aproaches with detailed computational procedures.