Pointyng Correction in Phase Equilibrium Thermodynamics of Non Polar Gases and Brines: A Review

Abstract

The development of an equation for Poynting correction, is of paramount importance in the field of modeling and interpretation of phase equilibrium thermodynamics in a wide range of temperatures and pressures /densities for practical applications in chemistry, physical chemistry, geochemistry and industrial technology. The unique previous existing equation for Poynting correction is a simple expression, represented by a product of a constant volume by a pressure difference between wich the correction is applied. [1] proposed an equation based on a semitheoretical expression for the partial molar volume at infinite dilution of volatile aqueous non-electrolyte solute (V 2 0) that considers as variables the density and isothermal compressibility of the solvent, as well as the second cross solvent-solute virial coefficient (12) and the second virial coefficient of pure solvent (11). The mathematical equation is applicable to solutes whose 12 is known or can be estimated, in a temperature range of 273.16 K to 647 K, values of pressure up to 2 kbar and brines with ionic strength equal to 6 m NaCl. The expression provides excellent correlation with experimental data as shown for the H2S-H2O-NaCl system (with maximum deviation of 7%), through a thermodynamic model that uses this formula proposal coupled with the Law of Henry and the Soave-Redlich-Kwong equation of state for modeling the liquidvapor phase equilibria.

Modeling of Liquid–Vapor Phase Equilibria of Pyrolysis Bio-oils: A Review

“…Assuming equilibrium conditions, when the fugacity of the liquid equals its vapor pressure at saturation, the liquid–vapor equilibrium for a species i in solution (eq ) can be rewritten as the following (eq ), making use of the activity coefficient ( γ i ) to account for the deviations to ideal liquid-phase behavior. y i stands for the vapor fraction of i , φ i V for the vapor phase fugacity coefficient, which can be obtained using an equation of state, P for the operating pressure, x i for the liquid fraction of i , f i * , L for the liquid phase reference fugacity, and θ i *, L stands for the Poynting correction to the pressure, relevant when the operational pressure is much higher than the vapor pressure at saturation. y i ϕ i V P = x i γ i P i * θ i * , L …”