CO₂-Philic [EMIM][Tf₂N] Modified Silica in Mixed Matrix Membrane for High Performance CO₂/CH₄ Separation

Abstract

Separation of carbon dioxide (CO2) from methane (CH4) using polymeric membranes is limited by trade-off between permeability and selectivity as depicted in Robeson curve. To overcome this challenge, this study develops membranes by incorporating silica particles (Si) modified with [EMIM][Tf2N] ionic liquid (IL) at different IL:Si ratio to achieve desirable membrane properties and gas separation performance. Results show that the IL:Si particle has been successfully prepared, indicated by the presence of fluorine and nitrogen elements, as observed via Fourier-Transform Infrared Spectroscopy (FTIR) and X-ray Photoelectron Spectrometer (XPS). Incorporation of the modified particles into membrane has given prominent effects on morphology and polymer chain flexibility. The mixed matrix membrane (MMM) cross-section morphology turns rougher in the presence of IL:Si during fracture due to higher loadings of silica particles and IL. Furthermore, the MMM becomes more flexible with IL presence due to IL-induced plasticization, independent of IL:Si ratio. The MMM with low IL content possesses CO2 permeance of 34.60 ± 0.26 GPU with CO2/CH4 selectivity of 85.10, which is far superior to a pure polycarbonate (PC) and PC-Sil membranes at 2 bar, which surpasses the Robeson Upper Bound. This higher CO2 selectivity is due to the presences of CO2-philic IL within the MMM system.

Analysis on the Performance of Designed Fluidized Bed Dryer for Drying Coffee Beans

“…The evaporated moisture from the surface would be carried out of the drier by suitable air speed. Furthermore, heated air conveyed the energy utilised to evaporate moisture at the coffee beans surface [13][14][15].…”

Recent progress in the development of ionic liquid‐based mixed matrix membrane for CO 2 separation: A review

“…The results showed that the CO 2 solubility property of anion had influenced the CO 2 permeability of the IL‐MMM. A similar impregnation method was also applied by other researchers in the modification of the inorganic fillers with IL before MMM fabrication 206,207 . Besides the simple impregnation method, Ilyas et al 208 used another modification approach to introduce the IL on the zeolite surface.…”

“…It has been identified that before reaching the plasticization pressure, the gas sorption mechanism follows the dual sorption model, which is typical for the glassy polymer. The Langmuir sites become saturated in the low‐pressure region, leading to permeability reduction 207 . Meanwhile, beyond the plasticization pressure, the gas transport mechanism is dominated by plasticization behavior 41 …”

Polymeric Membrane for CO2/CH4 Separation

“…Inorganic particles that are non-porous, for instance, silica, are used in membranes of nanocomposite structures [53,86]. Previous works stated that the additional void located at the interface between silica agglomerates and the polymers has the probability to induce permeability enhancement [114,125,126]. Sadeghi et al [127] studied CH4 and CO2 properties of transport through composite membrane made of silica and polybenzimidazole (PBI).…”