Amine‐impregnated natural zeolite as filler in mixed matrix membranes for CO₂/CH₄ separation

Abstract

Flat mixed matrix membranes (MMMs) comprising polysulfone and clinoptilolite-type natural zeolite were prepared by casting. Zeolite was modified with three alkylamines: ethanolamine (EA), bis(2-hydroxypropyl)amine (BHPA), and polyethylenimine (PEI) by the impregnation method. Impregnated zeolite samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and N 2 adsorption-desorption. The alkylamine loading extent determined by thermogravimetric analysis was 5.2, 4.8, and 8.5% for EA, BHPA, and PEI, respectively. Analyses of MMMs showed that the incorporation of impregnated zeolite affected the glasstransition temperature (T g ) and mixed-gas transport properties. In this regard, a decreasing trend of the T g values from 185.5 C for the polymeric membrane up to 176.6 C for Clino-EA-based MMM was recorded. In addition, the gas separation performance was evaluated at two different feed pressures. At 50 psi, MMMs showed an enhancement up to 30% on the CO 2 permeability (22.79 Barrer) and 55% on the CO 2 /CH 4 selectivity (45.78) in comparison with the polymeric membrane (CO 2 permeability 17.34 Barrer; CO 2 /CH 4 selectivity 29.38). These values varied depending on the alkylamine, BHPA being the most selective.

Preparation of polybenzimidazole‐based mixed matrix membranes containingmodified‐COK‐12 mesoporous silica and evaluation of the mixed‐gas separation performance

“…Mixed-gas permeability tests were performed with a customized permeation apparatus reported elsewhere, and following the same procedure. 32 Flat polymeric and MMMs (5 cm-diameter, 70-100 μmthickness, 5.06 cm 2 effective area tested) were placed onto a ceramic support (porosity: 3 μm, thickness 6 mm) between two-chamber cell. Helium (99.999%) was used for the baseline and as carrier gas.…”

“…For example, in a previous work of our research group, the incorporation of 10 wt% natural zeolite modified with different alkylamines had beneficial effects on the CO 2 /CH 4 mixed‐gas transport parameters of polysulfone‐based MMMs. Here, the enhancement up to 55% on selectivity and a little significant variation of CO 2 permeability could be accomplished by adding zeolite impregnated with a secondary hydroxyalkyl amine, in comparison with the pristine membrane 32 . In a similar context, Suhail et al 33 recently reported MMMs based on polysulfone and mesoporous SBA‐16 functionalized with pyrazole group.…”

“…Here, the enhancement up to 55% on selectivity and a little significant variation of CO 2 permeability could be accomplished by adding zeolite impregnated with a secondary hydroxyalkyl amine, in comparison with the pristine membrane. 32 In a similar context, Suhail et al 33 recently reported MMMs based on polysulfone and mesoporous SBA-16 functionalized with pyrazole group. A simultaneous increase in CO 2 permeability (up to 116%) and both CO 2 /CH 4 and CO 2 /N 2 selectivities (69% and 87%, respectively) were appreciated, whose behavior was induced by the nitrogen-containing organic functional group attached to silica structure.…”

PBI/Clinoptilolite mixed‐matrix membranes for binary (N2/CH4) and ternary (CO2/N2/CH4) mixed gas separation

“…Permeability system was previously described and reported. [28][29] The upstream side was pressurized to 50, 150, and 300 psi of feed gas mixture with a solenoid valve and determined with equipment pressure detector, additionally, has a downstream section with a pressure detector. This section was at atmospheric pressure (14.7 psi) using Helium as carrier gas.…”

Reducing the crystallinity of high molecular weight poly (ethylene oxide) using ultraviolet cross‐linking for preparation of gas separation membranes

“…[10][11][12][13] In recent years, polymeric membranes have received specific attention in the CO 2 separation applications, and in particular, rubbery polymers are more attractive due to their flexible chains allow the chain segments to rotate freely around the main chain bounds. [14][15][16] Low et al 17 indicated that rubbery polymers based on poly (ethylene oxide) (PEO) or poly (ethylene glycol) (PEG) emerge as promising candidates for the CO 2 separation membranes. The CO 2 selective PEO gas separation membranes have high CO 2 solubility by the ether oxygen group of the main chain based on Lewis acid-base interaction between ether oxygen (Lewis base) and CO 2 (Lewis acid).…”