separation of carbon dioxide from natural gas by matrimid-based mixed matrix membranes

Spherical mgo nanoparticles and flake-like clay minerals modified with polyaniline (pani) are applied in matrimid in order to fabricate mixed matrix membranes (mmms) having improved gas separation performance. the co2 permeability, co2/ch4 selectivity and co2-induced plasticization pressure of mmms are assessed at 4-30 bar feed pressure. the chemical structure, morphology and thermal properties of mmms are analyzed by fourier transform infrared equipped with attenuated total reflection (ftir-atr), x-ray diffraction, field emission scanning electron microscopy (fesem) and differential scanning calorimetry/thermogravimetric analyses. crater-like morphology is seen for mmms by fesem tests physical interaction of matrimid with mgo and pani, confirmed by ftir-atr, helps better distribution of both the fillers in the polymer matrix. mechanistical analysis of gas sorption and diffusion terms reveals that pani/clay (pc) enhances gas permeability by controlling diffusivity paths, while mgo nanoparticles improves both gas solubility and diffusivity. the permeability tests reveal that the sample pc5m5 with 5 wt% pc and 5 wt% mgo, has the best gas separation properties. high pressure tests reveal that this sample can enhance plasticization pressure and co2 permeability as well by 76% and 200%, respectively; resulting in 425% enhancement in mmms capacity in natural gas sweetening.