Fugacity propane

Figure 5.17 illustrates the effect on hydrate formation when ethane and propane are combined at constant temperature. Ethane acts as an inhibitor to sll formation due to competition of ethane with propane to occupy the large cages of sll. Propane also acts as an inhibitor to si formation when added to ethane+water. In this case, however, since propane cannot enter the si cavities, the fugacity of ethane is lowered as propane is added, destabilizing the si hydrate. Holder (1976) refers to this inhibiting capacity as the antifreeze effect. 

The chemical potential difference of water molecule between empty and occupied hydrate, iy, — fi l, is calculated accoi ding to either equation (14) or (18) as a function of the pressure of propane. The second virial coefficient is taken into account in calculating both the density and fugacity (or chemical potential) of propane in the gas phase which is assumed to be in equilibrium with the hydrate. If ice Ic is in equilibrium with hydrate at the given temperature, then the chemical potential of ice, equals to fiy, and therefore H-wi assuming — //. is independent of the... 

Figure 3. Fugacity coefficients of pure liquid propane (to = 0.153) in the...

Figure 6. Fugacity coefficients of pure liquid methane, ethane, propane, n-butane, and n-pentane at Tr = 0.4 (----------------------), this work (A), Chao tabulation and ( J), Kobayashi tabulation.

Table V presents fugacity coefficients, f/P, at T = 260 K for gaseous and liquid propane up to P = 700 bar, computed via...

Figure 4.5 Typical composition dependence of fugacity coefficients in gas mixtures. Fugacity coefficients in carbon dioxide + propane mixtures at 100°F, 200 psia. These curves are corrected from results tabulated by Walas [9].

R. D. Goodwin and W. M. Haynes, Thermophysical Properties of Propane from 135 to 700 K at Pressures to 70 MPa, U.S. Dept, of Commerce, National Bureau of Standards Monograph 170, 1982, 244 pp. Tabulated data include densities, compressibility factors, internal energies, enthalpies, entropies, heat capacities, fugacities and more. Equations are given for calculating vapor pressures, liquid and vapor densities, ideal gas properties, second virial coefficients, heats of vaporization, liquid specific heats, enthalpies and entropies. 

Example Illustrating the Use of Fugacity Corrections. Scheeline (Ref. 23) has studied the vapor-liquid equilibrium of propane-isobutylene mixtures at high pressures. Using the data and notes given below, make a y x plot for a total pressure of 400 p.s.i.a. showing... 

In preparing this table, it was assumed that the concentrations of all components lighter than propane were negligible in the residue and that all components heavier than n-Ci were negligible in the distillate. The isobutane is intermediate to the propane and n-butane and therefore will appear in appreciable quantities in both the distillate and residue. Since the i-C4 is more volatile than n-C4, the following table was prepared on the assumption that 20 per cent of the i-C4 in the feed would appear in the overhead. The volatilities relative to n-C4 are given in Fig. 9-13. These relative volatilities are based on the fugacity data of Lewis and coworkers (Ref. 6). The equilibrium constant K... 

Example 7.1 Estimate the fugacity of propane gas at 220°F and 500 psia. We will proceed in several ways, showing several possibilities. 

Determine the fugacity and fugacity coefficient of propane using the following approximations ... 

Consider a vapor phase mixture of 2 moles propane (1) and 3 moles nitrogen (2) at 15°C and 12 bar. You wish to come up with the fugacity and fugacity coefficient for propane. Answer the following questions using the truncated virial equation of state, as follows ... 

Using the Peng-Robinson equation of state, calculate the saturation pressure of pure (i) propane, (ii) n-butane, and (ui) n-pentane at 300 K by using fugacity coefQcients to calculate the fugacity for both vapor and Hquid phases. Compare the results with the values of Pf obtained by the Antoine equation and report the percent error. 

To find the saturation pressure at a given temperature, we solve Equation (E8.14A) for liquid and vapor volumes and then use those values in Equation (E8.14C) for the fugadty coefficient. This process requires iterative solution, and the saturation pressure is found as the pressure where the fugacity of the vapor and liquid are equal. The values that satisfy this criteria for propane, n-butane, and n-pentane at 300 K are shown in Table E8.14B. 

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