Comparison of CO2 absorption kinetics using AMP-MPDL, 30% wt. TEA and 15% wt. AMP-15% wt. TEA

https://doi.org/10.1016/j.ijggc.2022.103771

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In order to compare the rate of CO₂ absorption of novel formulated AMP-MPDL solvent with the conventional solvents (i.e., 30% wt. TEA and 15% wt. AMP-15% wt. TEA), a drop of pressure plot was used. As presented in Fig. 3, the slopes of the plots of novel formulated AMP-MPDL (15% wt. AMP-15% wt. MPDL, 10% wt. AMP-20% wt. MPDL, and 5% wt. AMP-25% wt. MPDL) are larger than that of conventional 30% wt. TEA. Furthermore, by comparing the novel formulated 15% wt. AMP-15% wt. MPDL (which showed the best kinetics performance among the three concentrations) with the conventional 15% wt. AMP-15% wt. TEA, it was observed that the rate of CO₂ absorption of novel formulated AMP-MPDL was much faster than that of conventional AMP-TEA. Regarding the slope of the drop of pressure plot presented in Fig. 3, it can be preliminary estimated that CO₂ absorption rate of the novel formulated 15% wt. AMP-15% wt. MPDL is 95% and 350% faster than that of the conventional 15% wt. AMP-15% wt. TEA and 30% wt. TEA, respectively. Thus, it can be concluded that the novel formulated AMP-MPDL solvent has a great potential for capturing CO₂ in terms of the absorption rate. Especially, in substitution of conventional AMP-TEA and TEA solvents. Also, in the aspect of CO₂ absorption kinetics, 15% wt. AMP-15% wt. MPDL is the most attractive among the studied concentration ratios.

Based on the results observed in the present study, it can be implied that the absorption column with novel formulated AMP-MPDL solvent will be shorter than that with conventional AMP-TEA and TEA solvents within the same operational condition. In other words, it can be said that for the same height of the absorption column, the novel formulated AMP-MPDL requires lower solvent circulation rate than the conventional AMP-TEA and TEA solvents [11]. This is due to the fact that AMP-MPDL possesses much faster overall CO₂ absorption rate than AMP-TEA and TEA. As a result, the energy requirement for solvent circulation via pump can be largely reduced in the case of using novel formulated AMP-MPDL solvent in comparison with conventional AMP-TEA and TEA solvents. Thus, it is worthwhile to mention that the novel formulated AMP-MPDL solvent showed a promising performance in terms of CO₂ absorption kinetics than the conventional AMP-TEA and TEA solvents. However, further investigation of the AMP-MPDL solvent on its mass transfer performance in packed column, solvent regeneration ability, solvent corrosiveness, and solvent stability should be conducted before being used as an alternative solvent for capturing CO₂ [12].”

“Fig. 3. Drop of pressure of CO₂ absorption in novel 30% wt. AMP-MPDL and that of conventional 30% wt. TEA and 15% wt. AMP-15% wt. TEA at 313 K.”