Evaluating diethanolammonium chloride as liquid solvent for gas separation from experiments and theoretical calculations
Jiayin Zhang, Siqi Fang, Lu Zheng, Xiong Li, Yongde Ma, Hongwei Zhang, Zhenping Cai, Yanning Cao, Kuan Huang, Lilong Jiang
Abstract
Abstract This study explored diethanolammonium chloride ([DEA]Cl) as a potential ionic liquid from low‐cost and commercial ones for gas separation. There are three kinds of functional sites in [DEA]Cl: acidic NH 2 + , hydrogen‐bond OH, and nucleophilic Cl − . The separation of NH 3 /N 2 /H 2 , SO 2 /CO 2 /N 2 , and H 2 S/CO 2 /CH 4 was considered, because the three mixtures are extensively involved in many industrial processes. The experimental results demonstrated that [DEA]Cl exhibited excellent ability to separate the mixture of NH 3 /N 2 /H 2 . The [DEA]Cl also exhibited the proper capacity to separate SO 2 /CO 2 /N 2 , but the capacity of [DEA]Cl for the separation of H 2 S/CO 2 /CH 4 was inferior. The theoretical calculations revealed that NH 2 + and OH worked synergistically to contribute to the ability of [DEA]Cl for excellent separation of NH 3 from NH 3 /N 2 /H 2 , with Cl − contributing to the proper separation of SO 2 from SO 2 /CO 2 /N 2 . This study provides experimental and theoretical basis for the industrial application of [DEA]Cl in the area of gas separation.