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when the liquid leaving the absorber is in equilibrium with the entering gas. This
occurs when the operating line intersects the equilibrium curve, as shown by the
dashed line in Figure 6.16. The intersection is given by Equation 6.21.1 A, which
is derived by the simultaneous solution of a component balance and an equilib-
rium relation.

Table 6.21 SUMMARY OF EQUATIONS FOR SIZING ISOTHERMAL
ABSORBERS AND STRIPPERS - COLUMN HEIGHT

Subscripts: L = liquid — V = vapor
1 = top of column — 2 = bottom of column — see Figure 6.16
m = minimum — k = key component

Minimum Flow Rates

Absorbers

m Lm Y2k'-yik
(6.21.1 A)

(6.21.2A)

—— = ———————— (6.21.1S)
mi/ KkXi k '-y 2 k'

x 2k = (l-£')xik' (6.21.2S)

Optimum Flow Rates

Absorbers

(6.21.3 A)

m v =1.5m vm (6.21.3 S)
Number of Equilibrium Stages
(6.21.4)
A A = m L /K k m v

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