Hexane Antoine vapor pressure

Table 13-1, based on the binary-system activity-coefficient-eqnation forms given in Table 13-3. Consistent Antoine vapor-pressure constants and liquid molar volumes are listed in Table 13-4. The Wilson equation is particularly useful for systems that are highly nonideal but do not undergo phase splitting, as exemplified by the ethanol-hexane system, whose activity coefficients are snown in Fig. 13-20. For systems such as this, in which activity coefficients in dilute regions may...

The necessary vapor pressures and activity coefficients are supplied by data correlations. For the system acetone(l)/n-hexane(2), vapor pressures are given by Eq. (4-142), the Antoine equation ... 

The system n-pentane(l)/n-hexane(2)/n-heptane(3) conforms closely to Raoult s law. The vapor pressures of the pure species are given by the following Antoine equations ... 

In this table, A, B, and C are Antoine equation constants, al, av, and bv are the coefficients of the given heat capacity formulas Tbp(°C) and DHv(kJ/mol) (A v) are the normal boiling point and heat of vaporization, xF(mol pentane/mol) is the mole fraction of pentane in the feed. TfCC) is the feed temperature, P(mm Hg) is the system pressure. HAF (Haf) and HBF (Hbf) are the specific enthalpies of pentane and hexane in the feed stream, pA is the vapor pressure of n-pentane (to be determined using the Antoine equation), x and nL x and l) are the mole fraction of pentane in the liquid product stream and the molar flow rate of that stream, respectively, y and nV are the corresponding properties of the vapor product stream. HAL is the specific enthalpy of pentane in the liquid product stream, and DH (A//) is the expression given in Equation 5 for the change in total enthalpy from inlet to outlet. 

Since the composition of the vapor and the pressure are given, the information is enough. Equations needed Mole balances on butane and hexane, Antoine equation and Raoult s law for butane and hexane... 

D14. We are feeding 100 kmol/h of a mixture that is 30 mol% n-butane and 70 mol% n-hexane to a flash drum We operate with V/F = 0.4 and = 100°C. Use Raoult s law to estimate K values from vapor pressures. Use Antoine s equation to calculate vapor pressure,... 

D2. What is the dew point of a vapor that is 30 mol% n-butane, 50 mol% n-pentane, and 20 mol% n-hexane at p = 760 mm Hg Use Raoult s law to predict K values. Find vapor pressures from Antoine s equation. 

Set the vapor fraction to 0 and the temperature to the desired temperature where you want to find out the vapor pressure. Then HYSYS will calculate the pressure the calculated pressure is the vapor pressure (or more precisely the bubble-point pressure = the vapor pressure) at the specified temperature—similarly, if you want to calculate the dew point, set the vapor fraction to 1. The result depends on many parameters, for example, selection of EOS, components in a mixture. Using Antoine equation, the vapor pressure of pure n-hexane at 130°C is 500.2 kPa (Figure 1.9), and the vapor pressure of pure n-heptane, n-octane, and n-nonane is 236 kPa, 113.4 kPa, and 56.33 kPa, respectively. The vapor pressure using Peng-Robinson EOS at 130 is 496 kPa, the same as that obtained by Antoine equation (Figure 1.10). For the gas mixture at 130°C, the vapor pressure is 280 kPa (Figure 1.11). 

Vapor pressure of pure n-hexane using Antoine equation. 

Estimate the vapor pressure of n-hexane and acetone using the corresponding states principle and compare the results with those obtained with the Antoine equation. 

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