Once an equation form of the equilibrium data is available, it is relatively easy to develop a spreadsheet to solve binary flash problems. We need to input the known values, which we will assume are the mole fraction of the more volatile component in the feed, z, and the fraction vaporized, V/F. Then input the constants for the VLE data in the form y_{MVC} = f(x_{MVC}). For this example we will separate ethanol and water at 1.0 atm with an ethanol feed that is 30 mol% ethanol and V/F = 0.4. The VLE equation for ethanol-water at 1.0 atm is given by Eq. (2.B-1). Next, input a guessed value for x_{ethanol}. Now calculate yeq using this value of xguess from Eq. (2.B-1) and calculate yop from Eq. (2-13). Since yop ...

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