As shown 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 (duration/time) The proportionality factor k depends on the diffusivity of the gas in the liquid and the situation of absorption, that is to say the surface area available for absorption and the flow rates of the gas and the absorbent2. In this project, the surface area available for absorption, diffusivity and gas flow rate will remain constant, so k depends mainly on the flow rate of the absorber. Once equilibrium is reached between the gas and the absorbent, the driving force for absorption becomes zero since the concentration difference between the gas and the bulk liquid no longer exists. The concentration gradient decreases as the gas rises in the column, constantly decreasing the driving force. This being the case, equation (3) can be differentiated with respect to the height, z, 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