TY  - JOUR
AU  - Gao, Pengfei
AU  - Li, Guilin
AU  - Peng, Kuilin
AU  - Chu, Haozhan
AU  - Bai, Yinge
AU  - Wang, Min
AU  - Feng, Jiaqi
AU  - Zhang, Xiangping
AU  - Zeng, Shaojuan
PY  - 2026
TI  - Phase separation behaviors and mechanisms of triazole-functionalized ionic liquid absorbents for energy-efficient CO2 capture
JO  - Industrial Chemistry & Materials
SN  - 2755-2608
SP  - 621
EP  - 633
VL  - 4
IS  - 5
AB  - Excessive carbon dioxide (CO2) emissions have triggered global warming and frequent extreme weather, highlighting the urgency of advancing carbon capture technologies. Although phase change absorbents offer notable benefits for efficient CO2 capture owing to low-energy regeneration volume enabled by phase separation, rational screening of high-performance ones remains challenging. In this work, three triazole-functionalized ionic liquids (TFILs) were synthesized and blended with organic solvents (as physical solvents or phase-separation agents) to develop novel TFIL absorbents for CO2 capture. When the mass ratio of the TFIL [Emmim][Triz] to DMSO was 6 : 4, the absorbent showed a CO2 capacity of 0.121 g CO2 (g absorbent)−1 at 40 ℃ and 1 bar, with the CO2-rich phase accounting for 98.5% of the total CO2 capacity and 53.85% of the total volume, and its regeneration energy consumption was only 1.12 GJ (t CO2)−1—70% lower than that of the conventional 30 wt% MEA solution. Mechanistic studies revealed that [Emmim][Triz] reacts with CO2 to form highly polar carbamate, and strong intermolecular hydrogen bonding between carbamate molecules lowers their solubility in the solvent, causing self-aggregation into a rich phase, while the DMSO distributes to the upper lean phase. Based on the polarity-driven phase separation mechanism, a phase change criterion for CO2 absorption by IL absorbents was proposed: phase change occurs when the dipole moment difference between the product and the phase-separating agent exceeds 12.41 D, which provides a quantitative basis for predicting phase separation behaviors in IL systems. This study developed a TFIL absorbent with excellent comprehensive performance for CO2 capture and presented a strategy for regulating phase separation behaviors of the absorbents.
UR  - https://doi.org/10.1039/d6im00153j
DO  - 10.1039/d6im00153j