A counter-current gas-absorption column is to be designed to remove CO₂ from an inert gas stream by reaction with an amine solution at 20°C. At this temperature, CO₂ reacts with the amine according to the following irreversible reaction:

The reaction kinetics is the first order in CO₂ and the first order in the amine, and the second-order rate constant is 10,200 L/mol s. The gas entering the column contains 10 mol% CO₂ while the gas leaving the column contains 0.1 mol% CO₂. The concentration of RNH₂ in the absorbent liquid is 1.75 mol/L at the top of the column and 1.00 mol/L at the bottom. The absolute pressure in the column is 10.0 atm. The following data can be used for this problem:

Using these data and neglecting the gas-side mass transfer resistance, determine the rate of absorption of CO₂ per unit column volume at the top and the bottom of the column.

CO + 2RNH + RNHCOO-+ RNH3*