A review of potential amine solvents for CO2 absorption process: Absorption capacity, cyclic capacity and pKa

Based on published data, no single amine showed superior performance in terms of absorption capacity and cyclic capacity. However, most of the studied amine solvents showed a better performance than MEA. In some cases, amines studied using the different screening techniques showed results which contradicted with the equilibrium value; the screening work seemed to lead to results where the equilibrium value was exceeded. Further, it was indicated that a solvent with promising cyclic capacity with desorption at 70 °C or 80 °C, not necessarily show the same potential with desorption at 120 °C. Thus, the value of the screening experiments can be questioned. At last, it was found a linear relationship between the pKa value of an amine solvent and its absorption capacity.