Property of diethanolamine glycinate ionic liquid and its performance for CO2 capture

A protic ionic liquid (IL), diethanolamine glycinate ([DEA][GLY]), was synthesized and characterized. Its physical properties, including density, viscosity, surface tension, conductivity and refractive index, were determined. CO2 solubility in [DEA][GLY] IL was also measured. Performances of [DEA][GLY] IL in absorbing CO2 in a bubble column were evaluated. The synthesized [DEA][GLY] is an amino acid-functionalized IL with dual groups of ammonium and amino. There was a good CO2 solubility in the IL at room temperature and atmospheric pressure, much better than the traditional ILs. Pure and aqueous [DEA][GLY] ILs are good CO2 absorbents. CO2 partial pressure and IL concentration have a significant impact on their absorption performance. [DEA][GLY] had an obvious advantage over the conventional ILs for CO2 absorption.