In the mixture with the countercurrent stage tower from the air-H2 mixture containing 2 mol% H2 at the beginning 80% of the H2 found in it is desired to be absorbed. There is 50 kg mol/h air inlet and 150 kgmol/h pure water inlet to the tower. The equation yA = 3*xA is given for H2 (A) at equilibrium. Calculate the number of steps required since the process takes place at 300 K and 101.3 KPa.