You have been asked to design a staged absorber for the removal of ammonia from air using water. The entering air stream has a flow rate of 500 moles/min and has an ammonia concentration of 8 mole%. We wish to remove 95 % of the ammonia and a senior engineer has suggested operation with a liquid flow rate that is 1.4 times the minimum value. Calculate the required water rate and the number of equilibrium stages required using the Kremser approach. Assume no air dissolves in the water and no water vaporizes. The phase equilibrium for the ammonia distributed between the air and water phases is well represented by y
