1.- A countercurrent absorption process is to be used to recover solute A from an inert gas. The concentration of A will be reduced from 28.5 mol% A to 5 mol% A on solute free basis by contact with a pure solvent.

a) Find the minimum liquid-to-vapor ratio on the free base of solute.

b) Determine the number of stages in equilibrium if the actual velocity of the liquid were 1.2 - times the minimum value.

c) The concentration of A in the solvent solution at the outlet.

The equilibrium relationship can be expressed by yA = 4.0 xA.

2.- The gaseous current described in the previous problem is fed to the column in parallel current together with a pure solvent. The concentration of A in the carrier gas,

As in the previous problem, it is reduced from 285 mol% A to 5 mol% A in free base. The actual velocity of the liquid is 1.2 times the minimum. Determine:

a) Ls/Gs minimum

b) Ls/Gs real

c) The concentration of A in the solvent solution at the outlet.