Development of a database system for searching and estimating properties of gases and liquids

Abstract

The objective of this research is to develop a database system for searching and estimating properties of gases and liquids. A program can be run on Windows plateform used with a personal computer. The program contains 150 compounds in its database. Relational database model is used to store data because the structure of this model is not complicated but easy to access. The program is designed for linking to other programs which are developed in the C++ language. The concept of object-oriented programming is used in the program; therefore it can be linked with other programs easily. Soave-Redlich-Kwong and Peng-Robinson equations are used to predict the properties of gases and liquids because these equations can be used within a wide range of condition. The results of prediction compared with those from HYSIM and reference data show that the program is able to predict the properties of gases and liquids accurately. Percent deviation is as follows: the deviation of vapor pressure is less than ±2%, the deviation of heat of vaporization less than ±7%, the deviation of compressibility factor less than ±10%, the deviation of molar volume less than ±10%, the deviation of enthalpy changes and entropy changes less than ±5%, the deviation of fugacity coefficient less than ±4.5%. the deviation of vapor-liquid equilibria less than ±5 %, the deviation of liquid viscosity less than ±8%.