In the process of obtaining H2 from the water gas, the following gaseous mixture is available: 62.8% H2; 33.4% CO2; 3.2% N2; 0.6% CH4, and the CO2 content must be reduced to 1% by volume by washing the mixture with water. Calculate the necessary quantity of water and the concentration of the liquid solution leaving the tower (expressed in Kg C02/Kg H2O) if 125% of the minimum quantity is used and the operation is verified isothermally at 12.4 C and

a) at 20 atm.

b) at 50 atm.

It can be assumed that under operating conditions the solubilities of H2, CH4 and N2 in water are negligible. Equilibrium data for this system (CO2 in water) at 12.4C expressed as p* (partial pressure of CO2 in the gas phase, atm) versus C (concentration of CO2 in water in cm3 of C02, at 12 .4C and 1 atm, per cm3 of water) are: