Using a McCabe-Thiele diagram for a binary system, show why the purity will be reduced compared to the base case if \(\mathrm{N}\) and L/D are constant and one of the diameter balancing methods in Figure 10-17 (base case is a saturated vapor feed) or Figure 10-18 (base case is a saturated liquid feed) is used to reduce the column volume. Although this demonstration is for a binary system, the logic is true for multicomponent systems also.

Figure 10-17

Figure 10-18

A B C F F, vapor Vapor Liq Vapor F, vapor Vapor