Physiochemical, Pseudocritical and Thermodynamic Characterizations of Natural Gases

Abstract

Physiochemical, pseudocritical, pseudoreduced and thermodynamic properties play an important role for determination natural gas quality and specifications. Nowadays natural gas regard as one of the importance natural source of energy supply due to its high heating value, clean source, no emissions and environmental friendly. In addition, it began to replace the oil as a fuel in various purposes and as essential feed for petrochemical industries. Consequently, the different properties of natural gas mixtures must be investigated to determine their specifications. This study was aiming to distinguish these properties using correlations and mathematical models for assessment. These properties include the physical such as molecular weight (M_w), density(ρ), specific gravity(γ), compressibility factor (z), gas viscosity (μ_g), gas formation volume factor (B_g), gas thermal compressibility (C_g) and water content as well as pseudocritical pressure (p_pc), pseudocritical temperature (T_pc), pseudoreduced pressure (p_pr), pseudoreduced temperature (T_pr). Also, the thermodynamic properties e. g. Gross heating value, thermal conductivity, and specific heat of natural gas mixtures were determined. The study has been conducted on the natural gases of Zelten, Al Ragoba, Al Hotaiba gasfields and Al Braiga terminal to predict and estimate the physical, pseudocritical and thermodynamic properties by using correlation and mathematical models methods. The obtained results revealed that there is a variance between these properties of the natural gas mixtures, which may be attributed to the chemical compositions of components and their behaviors. On the other hand, these characterizations can be used as guide to understand the gases behavior during the different operations and natural gases treatment processes. Keywords: Natural gas, physiochemical, pseudocritical, pseudoreduced thermodynamic properties, and correlations