High-pressure vapor-liquid

Prausnitz, J. M. and P. L. Cheuh, Computer Calculations for High Pressure Vapor-Liquid Equilibrium, Prentice-Hall Inc. (1968). 

Griswold, J., D. Andres and V. A. Klein, Determination of High Pressure Vapor-Liquid Equilibria. The Vapor-Liquid Equilibrium of Benzene-Toluene," Trans. Amer. Inst. Chem. Engrs. 39, 223 (1943). 

VI. Concentrated Solutions High-Pressure Vapor-Liquid Equilibria. 170... 

The difficulties engendered by a hypothetical liquid standard state can be eliminated by the use of unsymmetrically normalized activity coefficients. These have been used for many years in other areas of solution thermodynamics (e.g., for solutions of electrolytes or polymers in liquid solvents) but they have only recently been employed in high-pressure vapor-liquid equilibria (P7). 

It is difficult to measure partial molar volumes, and, unfortunately, many experimental studies of high-pressure vapor-liquid equilibria report no volumetric data at all more often than not, experimental measurements are confined to total pressure, temperature, and phase compositions. Even in those cases where liquid densities are measured along the saturation curve, there is a fundamental difficulty in calculating partial molar volumes as indicated by... 

The correlation of Chao and Seader has been computerized and has been used extensively in the petroleum industry. It provides a useful method for estimating high-pressure vapor-liquid equilibria in hydrocarbon systems over a wide range of temperature, pressure, and composition, and presents a significant improvement over the previously used A -charts first introduced by W. K. Lewis, B. F. Dodge, G. G. Brown, M. Souders, and others (see D6) almost forty years ago. However, the Chao-Seader correlation is unreliable at conditions approaching the critical. Various extensions have been proposed (G2), especially for application at extreme temperatures. 

It is easily possible to introduce refinements into the dilated van Laar model which would further increase its accuracy for correlating activity coefficient data. However, such refinements unavoidably introduce additional adjustable parameters. Since typical experimental results of high-pressure vapor-liquid equilibria at any one temperature seldom justify more than two adjustable parameters (in addition to Henry s constant), it is probably not useful for engineering purposes to refine Chueh s model further, at least not for nonpolar or slightly polar systems. 

While the dilated van Laar model gives a reliable representation of constant-pressure activity coefficients for nonpolar systems, the good agreement between calculated and experimental high-pressure phase behavior shown in Fig. 14 is primarily a result of good representation of the partial molar volumes, as discussed in Section IV. The essential part of any thermodynamic description of high-pressure vapor-liquid equilibria must depend,... 

Shibata, S.K., and S.I. Sandler, "High-Pressure Vapor-Liquid Equilibria of Mixtures of Nitrogen, Carbon Dioxide, and Cyclohexane", J. Chem. Eng. Data, 34,419-424(1989). 

Lazzaroni, M.J., Bush, D., Brown, J.S. and Eckert, C.A. (2005) High-pressure vapor-liquid equilbria of some carbon dioxide plus organic binary systems. Journal of Chemical and Engineering Data, 50 (1), 60-65. 

Leu, A.-D., Robinson, D.B. (1992) High-pressure vapor-liquid equilibrium phase properties of the octafluoropropane (K-218)-chlorodifluoromethane (Freon-22) binary system. J. Chem. Eng. Data 37, 7-10. 

High-Pressure Vapor-Liquid Equilibria from a Corresponding States Correlation with Emphasis on Asymmetric Mixtures," I EC Process Design and Development, 1978, 17, 324. 

A New Mixing Rule for Accurate Prediction of High Pressure Vapor-Liquid Equilibria of Gas/Large n-Alkane Systems... 

In summary, based on a rigorous approximation to the quasichemical solution derived by the present authors, a generalized GC-EOS was proposed for the estimation and the prediction of properties of real pure fluids and mixtures. Its applicability was demonstrated for high pressure vapor-liquid equilibria of pure or mixed fluids. Although not shown here, we. have further results with other functional groups which indicate the extended applicability of the present method. 

In this work, the basis for a proper answer to the selectivity problem between the two cited compounds is set. For this purpose, a high-pressure vapor-liquid equilibria circulation-type apparatus was designed and constructed. Some vapor-liquid equilibria (VLE) data of the binary systems C02-limonene and C02-linalool were determined and compared with data available in the literature. The results obtained were accurately correlated by a modified SRK equation of state that avoids the use of critical constants [16]. 

The schematic diagram of the high-pressure vapor-liquid equilibrium circulation-type apparatus is shown in Fig.l. The main piece of the equipment is a high-pressure phase equilibrium cell of approximately 100 cm3. The apparatus includes a compressed-air actuated piston-pump that allows to circulate one or both phases to bring the vapor and liquid in close contact with each other. This pump, the cell and all the related valves were placed in a constant-temperature water bath to have and to keep uniformely the desired temperature. 

Figure 1. High-pressure vapor-liquid equilibria circulation-type apparatus.

In order to correlate the results obtained, a modified SRK equation of state with Huron-Vidal mixing rules was used. Details about the model are reported in the paper by Soave et al. [16]. This approach is particularly adequated when experimental values of the critical temperature and pressure are not available as it was the case for limonene and linalool. Note that the flexibility of the thermodynamic model to reproduce high-pressure vapor-liquid equilibrium data is ensured by the use of the Huron-Vidal mixing rules and a NRTL activity coefficient model at infinite pressures. Calculation results are reported as continuous curves in figure 2 for the C02-linalool system and in figure 3 for C02-limonene. Note that the same parameters values were used to correlated the data of C02-limonene at 45, 50 e 60 °C. 

Gilliland, E.R. and Scheeline, H.W. 1940. "High-Pressure Vapor-Liquid Equilibrium for Systems Propylene-Isobutane and Propane-Hydrogen Sulfide", Ind. Eng. Chem., 32 48-54. 

Xu, N., J. Dong, Y. Wang, and J. Shi. 1992. "High Pressure Vapor Liquid Equilibria at 293 K for Systems Containing Nitrogen, Methane and Carbon Dioxide", Fluid Phase Equil., 81 175-186. 

Bamberger, A.G. Sieder, and G. Maurer. 2000. High-pressure (vapor + liquid) equilibrium in binary mixtures of (carbon dioxide + water or acetic acid) at temperatures from 313 to 353 K. /. Supercrit. Fluids 17 97-110. 

Plocker, U., Knapp, H., and Prausnitz, J. (1978) Ind Eng Chem Proc Des and Dev. 17, 243. Calculation of high-pressure vapor-liquid equilibria from a corresponding-states correlation with emphasis on asymmetric mixtures. 

Therefore, the scope of this chapter is to describe the results obtained using SAS with particular emphasis on the production of particles with controlled PS and PSD in the micrometric as well as in the nanometric range. We will try to understand the role of high pressure vapor-liquid equilibria (VLEs) in determining the morphology and particle size of precipitates. 

Figure 7 High-pressure vapor-liquid equilibrium diagram at 60 °C for the system DMSO-CO2 in the presence of Cefonicid...

Michelsen, M. Dahl, S. High-pressure vapor-liquid equilibrium with a UNIFAC-based equation of state. AIChE J. 1990, 36, 1829-1836. 

Be able to correlate high-pressure vapor-liquid equilibrium data using an equation of state (that is, to be able to compute the conditions of vapor-liquid equilibrium and develop x- T-x-y. and P-x-y diagrams using an equation of state (the method) (Sec. i 0.3)... 

Be able to predict high-pressure vapor-liquid equilibrium compositions using an equation of state when no experimental data are available (Sec. 10.3)... 

HIGH-PRESSURE VAPOR-LIQUID EQUILIBRIA USING EQUATIONS OF STATE METHOD)... 

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