As seen in both equations (1) and (2) the absorption rate is proportional to the concentration gradient and both equations can be simplified to equation (3 ): Ro = D / δ * (C- Co) (2.3) Where: k = proportionality factor (length/time) The proportionality factor k depends on the diffusivity of the gas in the liquid and on the absorption situation, i.e. on the surface Available for absorbent and gas absorption and flow rates2. In this design, the surface area available for adsorption, diffusivity and gas flow rate will remain constant, so k depends mainly on the adsorbent flow rate. Once equilibrium is reached between the gas and the absorbent, the driving force for absorption becomes zero since the concentration difference between the mass of gas and the liquid no longer exists. The concentration gradient decreases as the gas rises up the column, steadily decreasing the driving force. This being the case, equation (3) can be differentiated with respect to the z-height, and then integrated to determine the overall absorption within the column. Equations (4) and (5) represent differentiation and integration, respectively. Ro dz = K *( C-Co) dz