https://doi.org/10.1016/j.ijggc.2018.10.008
“First, the solutions were loaded with CO2 until a low absorption rate was achieved as it can be seen in Fig. 3. The obtained rich loadings (mol CO2/mol amine) and corresponding CO2 absorbed quantity (mol) were indicated directly on that figure for a quick comparison. As expected (Aronu et al., 2011), it can be seen that the loading values decreased with an increase of MEA concentration. This shows that even if there are more amine molecules in a given sample at higher concentrations, these amines are less effective individually to absorb CO2. Fig. 3 also revealed that a 10 wt% MEA concentration is clearly not enough to maintain a high absorption rate and that a concentration over 30 wt% is required. However, as MEA concentration increased over 50 wt%, the distance between the curves tend to reduce indicating, as in Section 3.1., that a high viscosity increase occurred and that absorption may be limited by mass transfer in the liquid phase.
Fig. 3. CO2 absorption curves for various MEA concentrations from a 20% CO2 flowrate at 100 ml/min. Achieved loading (mol CO2/mol amine) and quantity absorbed (mol) are indicated for comparison.”