Feasibility study of CO₂/N₂ separation intensification on supported ionic liquid membranes by commonly used impregnation methods

Abstract

This work presents the experimental research on feasible intensification of CO 2 /N 2 separation by utilization of the developed supported ionic liquid membranes (SILMs). SILMs were developed through specific impregnation of commercially available ceramic microfiltration/ultrafiltration membranes made by INOPOR and polydimethylsiloxane (PDMS) membranes made by Pervatech BV with chosen imidazolium based ionic liquids (ILs). The effects of operating parameters, impregnation method, and SILM thickness were analyzed. The impregnation was performed by coating and soaking methods at normal pressure and under vacuum. The proper impregnation of the ceramic support, especially in case of commercial PDMS membranes, allows to achieve two distinct, stable, highly selective separation layers. The comparison of separation efficiency of the investigated SILMs shows that SILM based on PDMS membrane prepared by coating with 1-ethyl-3-methylimidazolium acetate ([Emim][Ac]) has very good stability, high CO 2 /N 2 ideal separation factor of 152 and permeability of 2400 barrer. It was found that optimum operating conditions were feed temperature of 20°C and pressure below 200 kPa. The obtained results represent an interesting low cost alternative in the gas separation, especially when the choice of selectivity is the first priority. The comparison with literature data and upper bond Robeson correlation (2008) suggests, that applying an additional active separating IL layer and an appropriate impregnating method to the commercial ceramic membranes may result in significant improvement of separation efficiency.

Comparison of CO2 Separation Efficiency from Flue Gases Based on Commonly Used Methods and Materials

“…Experimental research is presented for the following CO 2 capture methods: absorption, adsorption and membrane separation. The experiments were carried out on experimental setups described in detail in previous works [99][100][101]. The main parts of the experimental setups were packed columns with CO 2 liquid solvents or solid adsorbents and a membrane separation module with ceramic and polymeric membranes, as well as the developed SILMs.…”

“…The membrane separation research was carried out on the experimental setup, described in detail in our previous work [101]. The main part of the setup is a stainless steel module with a tubular ceramic membrane.…”

“…] by coating and soaking methods. The effects of pressure, temperature, pore diameter and impregnation method on CO 2 /N 2 separation were investigated [101]. Some experimental separation results are presented in Figures 6-9.…”

“…on CO2/N2 separation were investigated [101]. Some experimental separation results are presented in Figures 6-9.…”