Vapor-liquid equilibrium diagram, acetone

Fig. 8. Vapor-liquid equilibrium diagram for acetone (1) + water (2). UNIQUAC and Wilson parameters from ab initio calculations. Experimental data from Gmehling et al. (1977 onward).

FIGURE 8.9 (a) Partial and total pressure of acetone-chloroform at 60°C. (b) Activity coefficients for acetone and chloroform at 1.00 atm. (c) Vapor-liquid equilibrium diagram for acetone-chloroform solutions at 1.00 atm. (d) Vapor-liquid equilibrium phase diagram for acetone-chloroform at 1.00 atm. 

Once the interaction energies were obtained, they were used to calculate the parameters in the UNIQUAC and Wilson models given by Eq. (24). To test the validity of the method, low-pressure vapor-liquid equilibrium (VLE) predictions were made for several binary aqueous systems. The calculations were done using the usual method assuming an ideal vapor phase (Sandler, 1999). Figures 7 and 8 show the low-pressure VLE diagrams for the binary aqueous mixtures of ethanol and acetone [see Sum and Sandler (1999a,b) for results for additional systems and values of the... 

We cannot construct a liquid-vapor equilibrium diagram for nonideal solutions in the simple manner illustrated in Figure 14-16. For example, vapor pressures in acetone-chloroform solutions are lower than we would predict for ideal solutions and boiling temperatures are correspondingly higher. In acetone-carbon disulfide solutions, conversely, vapor pressures are higher... 

It is required to design a fractionation tower to operate at 101.3 kPa to obtain a distillate consisting of 95 mole% acetone (A) and 5 mole% water, and a residue containing 1 mole% A. The feed liquid is at 125°C and 687 kPa and contains 57 mole% A. The feed is introduced to the column through an expansion valve so that it enters the column partially vaporized at 60°C. Construct an H-x-y diagram and determine the molar ratio of liquid to vapor in the partially vaporized feed. Enthalpy and equilibrium data are as follows. 

Figure 7.12 shows a liquid-vapor phase diagram for positive deviations from Raoult s law. Each component has a higher-than-expected vapor pressure, so the total pressure in equilibrium with the liquid solution is also higher than expected. Ethanol/benzene, ethanol/chloroform, and ethanol/water are systems that show a positive deviation from Raoult s law. Figure 7.13 shows a similar diagram, but for a solution that shows a negative deviation from Raoult s law. The acetone/chloroform system is one example that exhibits such nonideal behavior. 

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