Synergistic SO 2 absorption in N ‐methyl ethanolamine/thiocyanate blends: Thermodynamic insights and energy optimization

作者：Bo Wang, Shuangjiang Li, Xiandong Hao, Wenbo Zhao, Zhiyong Xu, Yongming Luo · 发表于：AIChE Journal · 年份：2025 · DOI：10.1002/aic.70034 · 被引用次数：3 · 研究领域：Carbon Dioxide Capture Technologies、Ionic liquids properties and applications、Membrane Separation and Gas Transport

Abstract Traditional amine scrubbing for SO 2 capture typically dilutes alcohol amines with water to improve mass transfer, resulting in high volatility and desorption energy consumption. Inspired by the exceptional properties of ionic liquid (IL) 1‐ethyl‐3‐methylimidazolium thiocyanate ([EMIM][SCN]), we herein propose substituting water with [EMIM][SCN] in a novel SO 2 absorbent system based on N ‐methyl ethanolamine (MDEA). MDEA acts as the primary SO 2 absorbent, while [EMIM][SCN] serves as an auxiliary absorption component and physical properties regulator. Performance evaluations reveal that MDEA‐[EMIM][SCN] achieves high thermal stability (~483.15 K), low viscosity (~26 mPa s), excellent absorption capacity (~1.64 mol/kg at 298.15 K and 2000 ppm SO 2 ), high SO 2 /CO 2 selectivity (~101), and low desorption energy (approximately −95.6 kJ/mol). Thermodynamic modeling illustrates MDEA and [EMIM][SCN] contribute independently to absorption. Optimal energy consumption was determined by the proposed objective function. This work exemplifies the non‐aqueous alkanolamine/IL system for SO 2 capture, offering a promising approach for developing efficient, low‐energy SO 2 absorbents.