Influence of amine concentration on mass transfer

https://doi.org/10.1039/C7RA01352C

“In general, increasing the amine concentration causes an increase of the K_GCO2a_V values. This is because of the availability of an extra amount of amine molecules for CO₂ absorption at the interface of the gas and liquid, and this increases the possibility for CO₂ to react with amines over a larger active surface area.^33,60,76 As mentioned before, the absorption of CO₂ in amine solutions is a process, which is controlled by the liquid phase. As a result, this phenomenon decreases the resistance in the liquid phase and increases the mass transfer coefficient in the gas phase. However, increasing the concentration leads to an increase of the viscosity, which can hinder the diffusion of CO₂ into amines. Under these conditions, the balance between increasing K_GCO2a_V and the cost involved should be considered by increasing the amine concentration.”