Carbon dioxide absorption into phase‐change solvent in a packed column: Experimental study and novel mass transfer model

Abstract Phase‐change absorbents have emerged as a promising approach for CO 2 capture due to their substantial energy‐saving potential. Compared to traditional absorbents, phase‐change absorbents undergo phase separation after CO 2 absorption, leading to changes in viscosity and mass transfer behavior. These alterations introduce significant inaccuracies in the predictions of existing mass transfer models when applied to phase‐change absorbents. This study proposes a novel model for predicting the CO 2 mass transfer performance in packed columns. The newly developed model was validated through experimental studies. Specifically, the mass transfer behavior and phase separation performance of phase‐change absorbents during CO 2 absorption were systematically examined under various operational parameters. The results indicated that the operational parameters have a significant impact on mass transfer and phase separation behavior. Based on the two‐film theory, a new overall mass‐transfer coefficient ( K G a v ) for phase‐change absorbents was proposed. Compared to existing mass transfer models, it achieves more accurate prediction results, reducing the average absolute deviation from 10.6% to 8.3%. This model can also be used to assist in determining the phase separation conditions of the phase change absorbent. This method would greatly facilitate the evaluation of amine absorbents in packed columns and promote the development of amine‐based processes.