Stabilization of [BMIM][PF6] ionic liquid membrane in structurally optimized multilayer ceramic support through aqueous DEA solution for CO2/CH4 separation

• Published in: Journal of industrial and engineering chemistry (Seoul, Korea) Vol. 127; pp. 125 - 137
• Main Authors: Mahdavi, Hamid Reza, Arzani, Mehran, Faramarzi, Hamed, Bakhtiari, Omid, Mohammadi, Toraj
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 25.11.2023; 한국공업화학회
• Subjects: Ceramic Supports; CO2 Capture; Ionic Liquids; Stability; Supported Liquid Membranes; 화학공학; Ionic Liquids; Ceramic Supports; Stability; CO2 Capture; Supported Liquid Membranes
• ISSN: 1226-086X; 1876-794X
• DOI: 10.1016/j.jiec.2023.06.054

[Display omitted] •Stability of multilayer ceramic supported liquid membranes was experimentally studied.•Effect of substrate structure on multilayer ceramic support was investigated.•Effects of feed gas pressure and temperature on performance of supported ionic liquid membranes were investigated.•The support containing substrate made at higher pressing pressure showed longer stability.•Supported liquid membranes using the ionic liquid as solvent provided higher stability. The stability of the ceramic supported liquid membranes (SLMs) is one of the most interesting research subjects. In this work, the SLMs’ stability for CO2/CH4 separation was investigated. Following pressing α-Al2O3 substrates at 400, 600, and 800 bar, colloidal and polymeric TiO2 intermediate and top layers were coated. Aqueous diethanolamine (DEA) solution was used as solvent in the SLM to optimize support structure based on CO2/CH4 separation performance. The pressed support at 800 bar and coated with TiO2 demonstrated best performance and selected for further study. Subsequently, 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) ionic liquid (IL) was immobilized inside the selected support and used as the supported ionic liquid membrane (SILM) for CO2/CH4 separation. The SILM separation performance was evaluated under different pressures and temperatures. Temperature was found to has greater effect than pressure due to a decrease in IL's viscosity and an increase in penetrant diffusivity. At 25 °C and 1 bar, SILM exhibited consistent and reliable performance as CO2 and CH4 permeabilities of 244.0 and 7.4 Barrer, respectively, and CO2/CH4 selectivity of 33.0 over 6 h. The findings contribute to understanding the implementation of multilayer ceramic SILMs for CO2/CH4 separation and highlight its potential along with opening up new avenues.