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Peng Robinson

Hydrocarbon mixtures are most often modeled by the equations of state of Soave, Peng Robinson, or Lee and Kesler. [Pg.138]

Penetrating stains Penetration resistance Penetration theory Penetrometers Peng-Robinson equation DL-Pemcillamine Penicillamine [52-67-5]... [Pg.729]

In each of these expressions, ie, the Soave-Redhch-Kwong, 9gj j (eq. 34), Peng-Robinson, 9pj (eq. 35), and Harmens, 9 (eq. 36), parameter 9, different for each equation, depends on temperature. Numerical values for b and 9(7) are deterrnined for a given substance by subjecting the equation of state to the critical derivative constraints of equation 20 and by requiring the equation to reproduce values of the vapor—Hquid saturation pressure,... [Pg.485]

Corresponding states have been used in other equations. For example, the Peng-Robinson equation is a modified RedHch-Kwong equation formulated to better correlate vapor—Hquid equiHbrium (VLE) vapor pressure data. This equation, however, is not useful in reduced form because it is specifically designed to calculate accurate pressure data. Reduced equations generally presuppose knowledge of the pressure. [Pg.240]

Vapor densities for pure compounds can also be predicted by cubic equations of state. For hydrocarbons, relatively accurate Redlich-Kwong-type equations such as the Soave and Peng-Robinson equations are often used. Both require only T, and (0 as inputs. For organic compounds, the Lee-Erbar-EdmisteF" equation (which requires the same input parameters) has been used with errors essentially equivalent to those determined for the Lydersen method. While analytical equations of state are not often used when only densities are required, values from equations of state are used as inputs to equation of state formulations for thermal and equilibrium properties. [Pg.402]

Outlined below are the steps required for of a X T.E calciilation of vapor-phase composition and pressure, given the liquid-phase composition and temperature. A choice must be made of an equation of state. Only the Soave/Redlich/Kwong and Peng/Robinson equations, as represented by Eqs. (4-230) and (4-231), are considered here. These two equations usually give comparable results. A choice must also be made of a two-parameter correlating expression to represent the liquid-phase composition dependence of for each pq binaiy. The Wilson, NRTL (with a fixed), and UNIQUAC equations are of general applicabihty for binary systems, the Margules and van Laar equations may also be used. The equation selected depends on evidence of its suitability to the particular system treated. Reasonable estimates of the parameters in the equation must also be known at the temperature of interest. These parameters are directly related to infinite-dilution values of the activity coefficients for each pq binaiy. [Pg.539]

The methanol(l)/acetone(2) system serves as a specific example in conjunction with the Peng/Robinson equation of state. At a base temperature To of 323.15 K (50°C), both XT E data (Van Ness and Abbott, Jnt. DATA Ser, Ser A, Sel. Data Mixtures, 1978, p. 67 [1978]) and excess enthalpy data (Morris, et al., J. Chem. Eng. Data, 20, pp. 403-405 [1975]) are available. From the former. [Pg.540]

A variety of equations-of-state have been applied to supercritical fluids, ranging from simple cubic equations like the Peng-Robinson equation-of-state to the Statistical Associating Fluid Theoiy. All are able to model nonpolar systems fairly successfully, but most are increasingly chaUenged as the polarity of the components increases. The key is to calculate the solute-fluid molecular interaction parameter from the pure-component properties. Often the standard approach (i.e. corresponding states based on critical properties) is of limited accuracy due to the vastly different critical temperatures of the solutes (if known) and the solvents other properties of the solute... [Pg.2002]

In some earlier work the shift reaction was assumed always at equilibrium. Fiigacities were calculated with the SRK and Peng-Robinson equations of state, and correlations were made of the equilibrium constants. [Pg.2079]

The existing equations of state (i.e., Benedict-Webb-Rubin (BWR), Soave-Redlich-Kwang, and Peng-Robinson) have some practical limitations. The equations of state developed by the University of Illinois... [Pg.73]

There are many other specific techniques applicable to particular situations, and these should often be investigated to select the method for developing the vapor-liquid relationships most reliable for the system. These are often expressed in calculation terms as the effective K for the components, i, of a system. Frequently used methods are Chao-Seader, Peng-Robinson, Renon, Redlich-Kwong, Soave Redlich-Kwong, Wilson. [Pg.12]

The fugacity coefficient can be calculated from other equations of state such as the van der Waals, Redlick-Kwong, Peng-Robinson, and Soave,d but the calculation is complicated, since these equations are cubic in volume, and therefore they cannot be solved explicitly for Vm, as is needed to apply equation (6.12). Klotz and Rosenburg4 have shown a way to get around this problem by eliminating p from equation (6.12) and integrating over volume, but the process is not easy. For the van der Waals equation, they end up with the relationship... [Pg.256]

Equations of state that are cubic in volume are often employed, since they, at least qualitatively, reproduce the dependence of the compressibility factor on p and T. Four commonly used cubic equations of state are the van der Waals, Redlich-Kwong, Soave, and Peng-Robinson. All four can be expressed in a reduced form that eliminates the constants a and b. However, the reduced equations for the last two still include the acentric factor u> that is specific for the substance. In writing the reduced equations, coefficients can be combined to simplify the expression. For example, the reduced form of the Redlich-Kwong equation is... [Pg.631]

Figure A3.3 compares the experimental (corresponding states) results with the predictions from the van der Waals. modified Berthelot, Dieterici, and Redlich-Kwong equations of state.b The comparison is not so direct for the Soave and Peng-Robinson equations of state, since the reduced equation still includes to, the acentric factor. Figure A3.4 compares the corresponding states line, with the prediction from the Soave equation, using four different values of to. The acentric factors chosen are those for H (o> = —0.218), CH4 (to = 0.011),... Figure A3.3 compares the experimental (corresponding states) results with the predictions from the van der Waals. modified Berthelot, Dieterici, and Redlich-Kwong equations of state.b The comparison is not so direct for the Soave and Peng-Robinson equations of state, since the reduced equation still includes to, the acentric factor. Figure A3.4 compares the corresponding states line, with the prediction from the Soave equation, using four different values of to. The acentric factors chosen are those for H (o> = —0.218), CH4 (to = 0.011),...
Figure A3.5 Comparison of the experimental r (dashed lines) with the r values calculated from the Peng-Robinson equation of state (solid lines). Values for the acentric factor are (a) = —0.218 (the value for HU), (b) = 0.011 (the value for CH4),... Figure A3.5 Comparison of the experimental r (dashed lines) with the r values calculated from the Peng-Robinson equation of state (solid lines). Values for the acentric factor are (a) = —0.218 (the value for HU), (b) = 0.011 (the value for CH4),...
NH3 (a = 0.250), and H20 (u> = 0.344). Thus, results for a wide range of acentric factors are compared. In Figure A3.5, we make the same comparisons with the Peng-Robinson equation. [Pg.637]

For both the Soave and Peng-Robinson equations, the fit is best for uj — 0. The Soave equation, which essentially reduces to the Redlich-Kwong equation when ui — 0, does a better job of predicting than does the Peng-Robinson equation. The acentric factors become important when phase changes occur, and it is likely that the Soave and Peng-Robinson equations would prove to be more useful when 77 < 1. [Pg.637]

The value of v is important both in equation 7 and for accurate calculation of concentrations in other equations. For simplicity and accuracy, the Peng-Robinson equation of state has been used to calculate v for the model O). This equation expresses the P-V-T relationship as follows ... [Pg.203]

Volumetric equations of state (EoS) are employed for the calculation offluid phase equilibrium and thermo-physical properties required in the design of processes involving non-ideal fluid mixtures in the oil, gas and chemical industries. Mathematically, a volumetric EoS expresses the relationship among pressure, volume, temperature, and composition for a fluid mixture. The next equation gives the Peng-Robinson equation of state, which is perhaps the most widely used EoS in industrial practice (Peng and Robinson, 1976). [Pg.5]

Leu and Robinson (1992) reported data for this binary system. The data were obtained at temperatures of 0.0, 50.0, 100.0, 125.0, 133.0 and 150.0 °C. At each temperature the vapor and liquid phase mole fractions of isobutane were measured at different pressures. The data at 133.0 and 150.0 are given in Tables 14.9 and 14.10 respectively. The reader should test if the Peng-Robinson and the Trebble-Bishnoi equations of state are capable of describing the observed phase behaviour. First, each isothermal data set should be examined separately. [Pg.266]

The Peng-Robinson equation is related to the Redlich-Kwong-Soave equation of state and was developed to overcome the instability in the Redlich-Kwong-Soave equation near the critical point Peng and Robinson (1970). [Pg.342]

In process design calculations, cubic equations of state are most commonly used. The most popular of these cubic equations is the Peng-Robinson equation of state given by3 ... [Pg.57]

Example 4.1 Using the Peng-Robinson equation of state ... [Pg.58]


See other pages where Peng Robinson is mentioned: [Pg.75]    [Pg.389]    [Pg.531]    [Pg.531]    [Pg.1255]    [Pg.1505]    [Pg.415]    [Pg.632]    [Pg.660]    [Pg.16]    [Pg.230]    [Pg.230]    [Pg.230]    [Pg.261]    [Pg.264]    [Pg.265]    [Pg.265]    [Pg.434]    [Pg.342]    [Pg.58]    [Pg.59]   
See also in sourсe #XX -- [ Pg.34 , Pg.36 , Pg.37 , Pg.59 , Pg.64 , Pg.74 , Pg.82 , Pg.84 , Pg.90 , Pg.91 , Pg.96 , Pg.97 , Pg.221 ]

See also in sourсe #XX -- [ Pg.171 ]

See also in sourсe #XX -- [ Pg.1044 ]




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Equation of state Peng-Robinson

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Fugacity coefficients, Peng-Robinson

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PenG (

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Robinson

Volume-translated Peng-Robinson equation

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