Q.1 (4.0 Points) When molasses is fermented to produce a liquor containing ethyl alcohol, a CO2-rich vapor containing a small amount of ethyl alcohol is evolved. The alcohol can be recovered by absorption with water in a sieve-tray tower. For the following conditions, determine the number of equilibrium stages required for countercurrent flow of liquid & gas, assuming isothermal, isobaric conditions in the tower and neglecting mass transfer of all components except ethyl alcohol. Entering gas: 180 kmol/h; 98% CO2; 30C, 110 kPa Entering Liquid absorbent: 100% water; 300C, 110 kPa Required recovery (absorption) of ethyl alcohol: 97%. Equilibrium relation is given by: y = 0.57 x (y & x are mole fractions of ethyl alcohol in vapor & liquid respectively). Use mole ratios (X,Y). Actual liquid flow rate = 1.5 times the minimum liquid flow rate