Synergetic effect of phosphonium-based ionic liquid and amine-functionalized metal organic framework for separation of CO2 and CH4 using mixed matrix membranes

Fossil fuels have emerged as one of the main sources of energy for human civilization in recent times. Greenhouse gas emissions are the result of numerous industries’ excessive dependence on fossil fuels as a source of energy. According to several studies and statistics, the atmosphere’s CO2 concentration is close to 422.80 parts per million. Additionally, the World Meteorological Organization reports that the CO2 concentration is increasing by 2 ppm annually. This work explains integrated functionalized metal-organic frameworks and ionic liquids into polyether-block-amide (Pebax-1657) mixed matrix membranes to improve CO2 permeability and CO2/CH4 selectivity. Various filler loadings of 5%, 10%, and 15% (relative to the polymer) were produced. Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis, X-ray diffraction (XRD), and scanning electron microscopy (SEM) were employed to ascertain the surface and cross-sectional morphology, characteristics, and functional groups of the metal-organic framework and the fabricated membranes. Permeation investigations utilizing both single-gas and mixed-gas methods were conducted for each membrane. The engineered membranes demonstrated remarkable efficacy, attaining a CO2 permeability of 226.37 Barrer and a selectivity of 25.4 for the CO2/CH4 mixture, thereby presenting new opportunities for improved CO2 separation and effective carbon capture.