The volumetric and thermodynamic functions correlated by Pitzer and co-workers analytically represented with improved accuracy by a modified BWR equation of state. The representation provides a smooth transition between the original tables of Pitzer et al. and more recent extensions to lower temperatures. It is in a form particularly convenient for computer use.

A generalized thermodynamic correlation based on three‐parameter corresponding states

Contact angle measurement and contact angle interpretation

A new equation of state for the thermodynamic properties of natural gases, similar gases, and other mixtures, the GERG-2008 equation of state, is presented in this work. This equation is an expanded version of the GERG-2004 equation. GERG-2008 is explicit in the Helmholtz free energy as a function of density, temperature, and composition. The equation is based on 21 natural gas components: methane, nitrogen, carbon dioxide, ethane, propane, n-butane, isobutane, n-pentane, isopentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, hydrogen, oxygen, carbon monoxide, water, hydrogen sulfide, helium, and argon. Over the entire composition range, GERG-2008 covers the gas phase, liquid phase, supercritical region, and vapor–liquid equilibrium states for mixtures of these components. The normal range of validity of GERG-2008 includes temperatures from (90 to 450) K and pressures up to 35 MPa where the most accurate experimental data of the thermal and caloric properties are represented to within their accura...

The GERG-2008 Wide-Range Equation of State for Natural Gases and Other Mixtures: An Expansion of GERG-2004

An equation of state (EoS) suitable for describing associating fluids is presented. The equation combines the simplicity of a cubic equation of state (the Soave−Redlich−Kwong), which is used for the physical part and the theoretical background of the perturbation theory employed for the chemical (or association) part. The resulting EoS (Cubic Plus Association) is not cubic with respect to volume and contains five pure compound parameters which are determined using vapor pressures and saturated liquid densities. Excellent correlations of both vapor pressures and saturated liquid volumes are obtained for primary-alcohols (from methanol up to 1-tridecanol), phenol, tert-butyl alcohol, triethylene glycol, and water. Moreover, excellent prediction of saturated liquid volumes may be obtained from parameters which have been estimated by regressing only vapor pressures. Finally, we suggest a method for reducing the number of adjustable parameters for alcohols to three while maintaining the good correlation of vap...

An Equation of State for Associating Fluids

This chapter is concerned with the properties of gases and liquids (primarily water) relevant to Environmental Physics. Physical properties of gases such as density, heat capacity, and molecular diffusivity influence many of the exchanges between organisms or land surfaces and their environment. Evaporation of water from soils, plants, and animals is also important for their heat balance. Basic equations are developed here to specify the Equation of State of gases and the principles by which the state of liquid water can be specified‘ in organisms and soil. These principles will be applied in later chapters.

Properties of Gases and Liquids

A new solution to the kinetics of a fixed-bed adsorber in response to a step change in feed concentration is obtained for a linear equilibrium system, considering the resistance to mass transfer in both the mobile and stationary phases. The differential equations of continuity and mass transfer are integrated by simulating the intraparticle concentration profile with a parabola. The results agree with Rosen's rigorous but complex solution.

Kinetics of fixed‐bed adsorption: A new solution

A group contribution molecular model is developed for the thermodynamic properties of polar and nonpolar liquids and their solutions, including energy of vaporization, ρVT relations, excess properties, and activity coefficients. The model is based on the cell theory in which the repulsive forces of molecules are expressed with a modified cell partition function derived from the Carnahan-Starling equation of state for hard spheres. The attractive forces are made up of group pair interaction contributions. Group and interaction properties have been determined for methyl, methylene, hydroxyl, and carbonyl. Extensive comparisons are made of predictions of the model with data for pure liquids and their solutions.

A group contribution molecular model of liquids and solutions

Vapor-liquid equilibrium in binary mixtures of carbon dioxide + n-decane and carbon dioxide + n-hexadecane

An equation of state is obtained to describe the fluid state from the supercritical gas to subcritical vapor and liquid for small and large molecules of organic and inorganic substances. The perturbation theory of the fluid state is extended to include rotational contribution of molecular motion in addition to translational and the attractive force contributions. Three equation constants describe a substance and values are presented for 22 substances. Application is made to mixtures with emphasis on their phase equilibria.

Chain‐of‐rotators equation of state

Compositions of saturated equilibrium liquid and vapor phases are determined in a flow apparatus for mixtures of methane and n-decane at 150, 240, 270, 290, and 310/sup 0/C, for methane and benzene at 150, 190, and 230/sup 0/C, and for methane and toluene at 150, 190, 230, and 270/sup 0/C. Pressures extend to near the criticals of the mixtures starting from 20 atm or from somewhat above the vapor pressure of the solvent whichever is higher. 6 figures, 4 tables.

Kwang-Chu Chao

Papers

Kinetics of fixed‐bed adsorption: A new solution

A group contribution molecular model of liquids and solutions

Vapor-liquid equilibrium in binary mixtures of carbon dioxide + n-decane and carbon dioxide + n-hexadecane

Chain‐of‐rotators equation of state

Gas-liquid equilibrium in binary mixtures of methane with N-decane, benzene, and toluene