Research On Characterizing Petroleum Fractions Based On Real Components Method And Its Application

The pseudo-components method is generally used to characterize petroleum fractions presently. Real components method is proposed recently, but most using normal paraffin. In order to characterize thermodynamic and reaction kinetic characteristics of petroleum fractions better, calculate the physical properties of petroleum fractions based on group contribution method as much as possibly, and obtain a high-precision of petrochemical process model, a characterization problem for petroleum fractions with real components which have structure information is studied in this dissertation.Firstly, based on the existing problems characterizing petroleum fractions with pseudo-components method and real components method, a new real components method is proposed in the dissertation, that is, according to the characteristic of petroleum fractions during different narrow distillation ranges, several real components containing structure information are used to characterize the narrow fractions. Secondly, physical properties and equilibrium flash vaporization of crude oil are calculated using the new method and other more than ten traditional correlation equations based on pseudo-components method and real components one. Compared with the experimental data, the result shows that the new method has higher precision about properties calculation, can eliminate the arbitrariness and complexity in choosing and matching the traditional correlation equations, and be able to make use of the advantage of group contribution method fully, so that it is an effective method to improve precision of process model. Finally, based on the new method, a non-equilibrium stage model of FCCU main fractional column is established. The steady model equations are turned into tridiagonal matrices by introducing separation efficiency function skillfully. A cutting iterative method is used to solve the model system of equations, which makes the model structure succinct and programming easy. Compared with the data of production process, the result indicates that the model of main fractional column based on the new method can represent steady and dynamic characteristic of the process. It's proved that the model and the new method are all reasonable and effective.