De Priester charts

A useful source of if-values for light hydrocarbons is the well-known De Priester charts , Dabyburjor (1978), which are reproduced as Figure 8.3a and b. These charts give the K-values over a wide range of temperature and pressure. 

Figure 8.3. (b) De Priester chart—. -values for hydrocarbons, high temperature... 

The K values, taken from the De Priester charts (Chapter 8), are plotted in Figure (a) for easy interpolation. 

At a pressure of 10 bar, determine the bubble and dew point of a mixture of hydrocarbons, composition, mol per cent n-butane 21, n-pentane 48, n-hexane 31. The equilibrium K factors can be estimated using the De Priester charts in Chapter 8. 

The composition of the feed to a debutaniser is given below. Make a preliminary design for a column to recover 98 per cent of the n-butane overhead and 95 per cent of the isopentane from the column base. The column will operate at 14 bar and the feed will be at its boiling point. Use the short-cut methods and follow the procedure set out below. Use the De Priester charts to determine the relative volatility. The liquid viscosity can be estimated using the data given in Appendix D. 

Assuming the validity of the De Priester charts, make the following VLE calculations for methane(l)/ethylene(2)/ethane(3) system ... 

The Peng-Robinson equation of state was used to estimate K values and enthalpy departures [as opposed to the De Priester charts used in Example 1 and by Seader (ibid.) who solved this problem by using the Thiele-Geddes (op. 

The equilibrium K factors can be estimated using the De Priester charts in Chapter 8. 

---