Phase identification of natural gas system with high CO₂ content through simulation approach using Peng-Robinson model

The phase behavior for natural gas mixtures with high CO₂ content and heavier hydrocarbons up to pentane for cryogenic separation has been obtained through simulation using Peng-Robinson (PR) model. The bubble point and dew point curves which define the liquid-vapor and solid-vapor domains for separation are obtained by generating the pressure-temperature phase diagram. The simulations are performed using Aspen HYSYS. The validation for the use of PR model is done by comparing the results of CO₂ freeze-out temperature predictions for PR and Soave-Redlich-Kwong (SRK) model with the experimental data available in the literature. (paper)