Equations of state Benedict-Webb-Rubin

Other pressure—volume—temperature (PVT) relationships may be found in the Hterature ie, Benedict, Webb, Rubin equations of state (4—7) the Benedict, Webb, Rubin, Starling equation of state (8) the Redlich equation of state (9) and the Redlich-Kwong equation of state (10). 

Benedict/Webb/Rubin Equation of State The BWR equation of state with Z as the dependent variable is written... 

As discussed in Sec. 4, the icomplex function of temperature, pressure, and equilibrium vapor- and hquid-phase compositions. However, for mixtures of compounds of similar molecular structure and size, the K value depends mainly on temperature and pressure. For example, several major graphical ilight-hydrocarbon systems. The easiest to use are the DePriester charts [Chem. Eng. Prog. Symp. Ser 7, 49, 1 (1953)], which cover 12 hydrocarbons (methane, ethylene, ethane, propylene, propane, isobutane, isobutylene, /i-butane, isopentane, /1-pentane, /i-hexane, and /i-heptane). These charts are a simplification of the Kellogg charts [Liquid-Vapor Equilibiia in Mixtures of Light Hydrocarbons, MWK Equilibnum Con.stants, Polyco Data, (1950)] and include additional experimental data. The Kellogg charts, and hence the DePriester charts, are based primarily on the Benedict-Webb-Rubin equation of state [Chem. Eng. Prog., 47,419 (1951) 47, 449 (1951)], which can represent both the liquid and the vapor phases and can predict K values quite accurately when the equation constants are available for the components in question. 

Benedict equation of etate phys chem An empirical equation relating pressures, temperatures, and volumes for gases and gas mixtures superseded by the Benedict-Webb-Rubin equation of state. ben-3,dikt i kwa-zhsn 3v stat ... 

The development of mixture rules will be discussed in detail in connection with the Benedict-Webb-Rubin equation of state. 

Benedict/Webb/Rubin equation of state, 84 Bernoulli equation, 217-218 Bubble point, 307, 309, 365, 454 Bubble-point calculations, 307-316, 381-393, 482-486, 490-493... 

Because the solubility of acrylamide (JEL), water ( ), and the surfactants in ethane or propane is low, the viscosity of the continuous phase was taken to be that of the pure fluid. The viscosity of the various ethane/propane mixtures was calculated using a reduced-density correlation developed by Dean and Stiel (IQ.), which is reported to be accurate to within 2 to 4% for light hydrocarbon mixtures. The density of the ethane/propane mixtures was either calculated via a modified Benedict-Webb-Rubin equation of state (11.) or, in some cases, measured using a Mettler-Paar DMA-512 vibrating tube densimeter. The densimeter was thermostated via a circulating water bath to within 0.01 C, and calibrated using water and propane at the ten ratures of interest. 

The values in these tables were generated from the NIST REFPROP software (Lemmon, E. W., McLinden, M. O., and Huber, M. L., NIST Standard Reference Database 23 Reference Fluid Thermodynamic and Transport Properties—REFPROP, National Institute of Standards and Technology, Standard Reference Data Program, Gaithersburg, Md., 2002, Version 7.1). The primary source for the thermodynamic properties is Outcalt, S. L., and McLinden, M. O., A Modified Benedict-Webb-Rubin Equation of State forthe Thermodynamic Properties of R152a (1,1-Difluoroethane), /. Phys. Chem. Ref. Data 25(2) 605-636,1996. Validated equations for the viscosity and thermal conductivity are not currently available for this fluid. 

More recently, Ustinov and coworkers [72, 73] developed a thermodynamic approach based on an equation of state to model the gas adsorption equilibrium over a wide range of pressure. Their model is based on the Bender equation of state, which is a virial-like equation with temperature dependent parameters based on the Benedict-Webb-Rubin equation of state [74]. They employed the model [75, 76] to describe supercritical gas adsorption on activated carbon (Norit Rl) at high temperature, and extended this treatment to subcritical fluid adsorption taking into account the phase transition in elements of the adsorption volume. They argued that parameters such as pore volume and skeleton density can be determined directly from adsorption measurements, while the conventional approach of He expansion at room temperature can lead to erroneous results due to the adsorption of He in narrow micropores of activated carbon. 

CONSTANTS AND MODIFICATIONS OF THE BENEDICT-WEBB-RUBIN EQUATION OF STATE... 

D. S. Viswanath and G.-J. Su Generalized Thermodynamic Properties of Real Gases, Part II. Generalized Benedict-Webb-Rubin Equation of State for Real Gases, AIChE J., 11(2) 205 (1965). 

A provisional thermodynamic network has been derived [ ] from spectroscopic and P-F-T data by use of an extension of the Benedict-Webb-Rubin equation of state developed by Strobridge [ ]. The range is 20 to 100°K on isobars from 1 to 340 atm. Older P-F-T data for normal hydrogen were used to extend the range to 300°K at pressures up tb 100 atm. The entire set of computations was repeated to obtain tables at uniform values of British engineering units as well. Users should obtain an errata sheet for all internal energies of... 

In addition to Eq. (7), a partition coefficient based on MMA mole fractions in the aqueous (Xmma) in the C02-rich phase (yMMA) can be calculated using a modified Benedict-Webb-Rubin equation of state [35] to estimate the molar densities of the phases assuming pure CO2 and water density, respectively. 

Values of Cp, Cy, internal energy E, enthalpy H, and entropy S of the real gas are also available from calculations using reference values for the ideal gas and a modified Benedict-Webb-Rubin equation of state, the melting curve, vapor and liquid density curves, and the vapor pressure curve mentioned above. They are parameterized in the same way (along coexistence lines and isochores) as the pgT data, see p. 202 [2]. In a similar manner, H and S were calculated earlier from a Martin-Hou equation of state, see p. 202 [3]. 

MBWR-EOS Modified Benedict-Webb—Rubin equation of state for Lennard-Jones system... 

During the mid-1970s, researchers at the National Institute of Standards and Technology (NIST) at Boulder, Colorado undertook a series of projects with the objectives of measuring and predicting the properties of liquefied natural gas and related mixtures. One result from this project was an extended corresponding-states model for liquefied natural gas densities developed by McCarty. That implementation used a 32-term, modified Benedict-Webb-Rubin equation of state for methane as the reference fluid and shape factors which had the same functional form as those proposed by Leach, but which had been re-fit to liquefied natural gas density data. The model reproduced the available liquefied natural gas density data to within 0.1 %. Eaton et alP used McCarty s methane equation to predict critical lines and VLB in (methane ethane). 

In 1973, Jacobsen and Stewart developed what is termed an advanced form of a modified Benedict-Webb-Rubin equation of state that has been given the acronym mBWR and is given by... 

McCarty, R. D. (1974). A Modified Benedict-Webb-Rubin Equation of State for Parahydrogen, NBSIR, 74-357. 

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