Chemical Engineering Journal ( IF 13.3 ) Pub Date : 2020-11-30 , DOI: 10.1016/j.cej.2020.127875 C.F. Martins , L.A. Neves , R. Chagas , L.M. Ferreira , C.A.M. Afonso , I.M. Coelhoso , J.G. Crespo , J.PB. Mota
Ionic liquids (ILs) with quaternary ammonium cations combined with biocompatible anions from renewable sources result in low-toxic, biocompatible, cost-efficient sorbent media that can efficiently capture carbon dioxide (). The understanding of the equilibrium and kinetics of absorption in these media is relevant for the design of new absorption processes in many application areas, such as removal from post-combustion streams, biogas refinery waste gases, or confined spaces. Here absorption in an aqueous solution of cholinium lysinate IL is studied both theoretically, via mechanistic modelling, and experimentally in a membrane contactor operated in closed loop with online measurement and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) analysis of discrete sampling of the circulating aqueous IL solution. It is shown that both techniques are effective tools for quantification in the liquid phase. The IL yields an absorption capacity of 2.20 moles of per mole of IL for an IL concentration of 2.13 M (or 50 wt% solution). A comprehensive model of chemisorption thermodynamics and absorption dynamics is proposed and validated experimentally. It provides not only the equilibrium constants of the reversible reactions of protonation of the amine groups and bicarbonate binding and overall mass-transfer coefficient based on liquid-phase concentrations, but is also the basis for a chemometric analysis of the experimental ATR-FTIR data. The potential use of ATR-FTIR as a monitoring tool of in aqueous solutions of cholinium lysinate IL is also demonstrated.
中文翻译:
造型 赖氨酸胆碱离子液体在水溶液中的吸收
带有季铵阳离子的离子液体(ILs)与可再生来源的生物相容性阴离子相结合,可产生低毒,生物相容性,成本效益高的吸附剂介质,可有效捕获二氧化碳()。对平衡和动力学的理解这些介质中的吸收与许多应用领域中新吸收工艺的设计有关,例如 从燃烧后气流,沼气精炼厂废气或密闭空间中清除。这里从理论上通过机理模型研究了赖氨酸胆碱IL水溶液中的吸收,并在闭环在线操作的膜接触器中进行了实验研究。 测量和衰减全反射傅里叶变换红外光谱(ATR-FTIR)分析循环IL水溶液的离散采样。结果表明,两种技术都是有效的工具液相定量。IL的吸收能力为2.20摩尔IL浓度为2.13 M(或50 wt%溶液)时,每摩尔IL的浓度为50%。提出了化学吸附热力学和吸收动力学的综合模型,并进行了实验验证。它不仅提供了基于液相浓度的胺基质子化和碳酸氢根结合的可逆反应的平衡常数和总传质系数,而且还提供了化学计量分析ATR-FTIR数据的基础。ATR-FTIR可能用作监测工具 还证明了在赖氨酸胆碱IL的水溶液中存在于乙醇中。