Modeling the Effect of CO2 on Thermodynamic Behavior of CO2/Libyan Natural Gas Mixture

Abstract

A great challenge has been done for utilization of natural gas (NG) for potential applications at various operating conditions. Accurate thermo-physical properties of NG play an important role in design and processing of NG systems. Among of these properties, compressibility factor, density, and viscosity of gas mixtures provide the feasibility of a given process. Carbon dioxide (CO2) is present in large quantities that produced from NG reservoirs. Understanding the effect of CO2 on thermodynamic properties of Libyan NG is important for developing the next generation of modern applications. The major thermodynamic properties considered in the present study were compressibility factor, density, and viscosity. The objective of this work is to investigate the effect of CO2 content on properties of Libyan NG using theoretical calculations. MATLAB logarithms were developed to predict the thermo-physical properties of Libyan NG with different CO2 concentrations. The effect of CO2 on thermodynamic behavior of NG mixture under different conditions of pressure and temperature was studied using the Redlich Kwong equation of state (RK-EoS). CO2 concentration has a great impact on the CO2/NG mixture properties. The results revealed that the compressibility factor of CO2/NG mixture is inversely proportional with the CO2 concentration; however, as CO2 content increases the gas mixture density increases.