A novel three pseudo-component approach (ThPCA) for thermodynamic description of hydrocarbon-water systems

Abstract

Thermodynamic description of the hydrocarbon processes facing considerable variation in composition such as gas-lift process require an accurate and speedy algorithm to perform the three-phase multi-component flash calculation based on an equation of state. A novel approach for thermodynamic description of the three-phase fluid is introduced in this study to overcome the complex and time-consuming multi-component flash calculation procedure. The constituents of each pseudo-component and their properties were determined employing an optimization method minimizing the difference between the results of the three pseudo-component approach (ThPCA) with those from the compositional approach. Performance results both in accuracy and computing speed for the ThPCA method showed that using the three optimum pseudo-components with flash calculations based on an equation of state, reduce the computational time by half compared to the compositional model while it only decreases the accuracy by 5 %.