Petroleum Distillate Property Estimation System Development

Oil and its fraction have certain boiling range. Not like pure substances and the fixed composition mixture which are easy to characterize and describe, they are special objects of study. The property of oil fraction need a lot of experiment data to correlate with different substances. The property that is difficult to measure is calculated and predicted by that is easy to measure accurately. A efficient oil fraction estimation system software is a useful tool that can help people design and developing processes. It also help chemical production and management. The basic physical properties of the petroleum fraction can be calculated easily by the system.The petroleum distillate property estimation process is studied in detail in this paper. The distillation data conversion methods is summarized in this paper, including ASTM D86 data into the true boiling point data, ASTM D1160 data into the true boiling point data and ASTM D2887 data into the true boiling point data. The cubic spline interpolation method, quadratic equation method and probability density equation fitting method is summarized. The cubic spline interpolation method is used to fit equation in this paper. This article summarizes a large number of petroleum distillate properties correlations including calculate normal boiling point, API, specific gravity, molecular weight, critical temperature, critical pressure and critical volume. It laid a solid foundation for the petroleum fraction estimation system. By the visual C++ programming language in the Visual Studio environment developed an object-oriented petroleum distillate property estimation system.The system interface for users is implemented. The users can input data and the program can calculate, transform and fit the input data automatically. We can do mutual transformation and curve fitting of distillation data, curve cutting and property estimation. The calculation results of this system is compared with the calculation result of Aspen Plus. Using Twu method and LK method calculate the properties. The comparison results show that the true boiling point transformation, normal boiling point, API gravity, specific gravity, critical temperature, the average relative error is less than 2%, the molecular weight and the critical pressure the average relative error calculated by Twu is larger, more than 5%. The calculation shows that the system can be estimated for petroleum fractions, but the calculation accuracy needs to be improved.The work has good practical value and it deserves to be studied and developed deeply.