In the simple binary batch distillation system shown in Figure 9-1 the vapor product is in equilibrium with liquid in the still pot at any given time. Since we use a total condenser, y = xD. Substituting this into Eq. (9-7), we have
where y and x are now in equilibrium and the equilibrium expression is y = f(x,p). For any given equilibrium expression, Eq. (9-8) can be integrated analytically, graphically, or numerically.
The general graphical or numerical integration procedure for Eq. (9-8) is:
1. Plot or fit y-x equilibrium curve.
2. At a series of x values, find y − x.
3. Plot 1/(y − x) vs. x or fit ...