Highly Selective CO<sub>2</sub>/CH<sub>4</sub>Membranes Based on Ethanolamine Ionic Liquids
Murilo L. Alcântara, Gerlon de Almeida Ribeiro Oliveira, Luciano M. Lião, Alfredo Ortiz, Silvana Mattedi
Abstract
High Resolution Image Download MS PowerPoint Slide In the pursuit of advanced carbon capture methods, ionic liquid (IL)-based membranes have emerged as promising materials for CO 2 separation due to their high permeation and selectivity. This research focuses on the development of composite membranes with highly CO 2 selective ethanolamine-based ionic liquids and poly(vinyl alcohol) (PVA). ILs and membranes were characterized by water content, FT-IR, 1 H, and 13 C NMR. The addition of ethanolamine-based ILs and stream humidification promoted an outstanding increase of PVA membranes’ CO 2 permeability and CO 2 /CH 4 selectivity of 53× and 36×, respectively. Effects of transmembrane pressure (1.0 to 3.0 barg), temperature (313.15 to 343.15 K), and CO 2:CH 4 ratio (10 to 40%) were studied. Effects of IL’s cations and alkyl chain length (anion) on CO 2 separation performance were studied via the production of PVA membranes with seven ethanolamine-based ILs. CO 2 permeabilities up to 209 barrer and selectivities up to 241 were obtained. The comparison of these membranes with some of the most promising materials in the literature indicates that the ethanolamine-based ILs + PVA membranes have moderate CO 2 permeabilities, associated with outstanding CO 2 /CH 4 selectivities.