Pure Gas Tests Research Articles

Development of high performance carbon molecular sieve membranes via tuning the side groups on PI precursors

In the current study, three 6FDA1/BPDA1-based polyimides (PIs) containing different diamine moieties (DMB, TCDB, TFDB) were selected to prepare CMS membranes (CMSMs), providing a systematic study of PIs with different side group functionalization. The resultant CMSMs were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectra, and CO2 absorption measurements. Pure gas (N2, O2, CH4, CO2) and mixed gas (CO2/CH4) permeability tests were also conducted. The resultant CMSMs exhibited attractive gas separation performance. Compared to DMB-based PI, TFDB-based with trifluoromethyl (-CF3) side groups exhibited ultra-high permeability (PCO2 = 14938 Barrer, PO2 = 3146 Barrer) and moderate selectivity (αCO2/CH4 = 20.3, αO2/N2 = 4.5), while CMSMs prepared from PI with chlorine functionalization showed higher gas permeability (PCO2 = 6031 Barrer, PO2 = 1311 Barrer) and selectivity (αCO2/CH4 = 46.2, αO2/N2 = 6.5). The results indicated that side group functionalization on PIs exerts a considerable influence on the gas permeation properties of CMSMs.

Understanding hydrogen solubility and free volume characteristics in charge-transfer phthalonitrile prepolymer and polyimide blend membranes

The increasing demand for hydrogen production has necessitated the development of H2-selective membranes. Polyimides are excellent membrane materials for gas separation; however, commercial polyimides generally lack sufficient H2 selectivity due to their low H2 affinity. Understanding the relationship between gas transport properties and free volume microstructure is critical to advancing H2-selective membrane design. Herein, we report a facile material strategy to adjust the free volume characteristics and H2 separation performance via blending Matrimid (PI) and crosslinkable resorcinol-based phthalonitrile prepolymer (RPN) with electron donor/acceptor properties. The novel RPN30/PI70 membrane exhibits H2/N2 and H2/CO2 permselectivity of 1637 and 66.4, respectively, with H2 permeability of 2.7 Barrer in pure gas test, surpassing Robeson upper bounds (2008). The increased H2 permselectivity of RPN/PI membranes was attributed to the narrowed free volume size and distribution, giving rise to the considerably improved H2 solubility and selectivity of the blends. Moreover, the H2 permeability of crosslinked RPN30/PI70 membranes can be further improved via thermal treatment. The H2/CO2 mixed-gas test reveals that the H2 gas separation performance of the RPN30/PI70 membrane is influenced by plasticization effect and competitive sorption. This study demonstrates a new versatile strategy for designing high-performance hydrogen-selective polymeric membranes.

Relationship between wet coating thickness and nanoparticle loadings based on the performance of mixed matrix composite membranes

Wet coating thickness and nanoparticle loadings are two important parameters that greatly impact the performance of mixed matrix composite membranes (MMCMs). In this work, two kinds of MMCMs, with Pebax as the continuous phase polymer and MIL-101(Cr) and UiO-66(Zr) as the dispersed phase porous materials respectively, were fabricated to explore the internal relationship between the two parameters. The change of membrane performance via adjusting wet coating thickness and nanoparticle loadings is discussed through pure gas and mixed gas tests and shown by contour data analysis. Generally, the wet coating thickness is significant to keep the membrane densification and nanoparticle loadings to increase the permselectivity to some degree. In addition, the nanoparticle size shows great impact on membrane performance due to the small-size nanoparticles with huge surface energy. At last, this work verifies that reinforcing the interaction between nanoparticles and polymer matrix is beneficial to improve the membrane performance.

Fabricating Leaf-like hierarchical ZIF-67 as Intra-Mixed matrix membrane microarchitecture for efficient intensification of CO2 separation

Mixed matrix membranes (MMMs) consisting of poly(ether-block-amide) (Pebax 1657) as the continuous phase and hierarchical leaf-like ZIF-67-L as dispersed microarchitectures for CO2/N2 separation were fabricated. The multidimensional channels and open interaction sites provided stable and rapid CO2 transmission, the intrinsic ZIF-67 crystal characteristics and unique leaf-like morphology-oriented crystalline arrangements provided extra CO2/N2 selectivity contribution, and the “trade-off” effect was successfully overcome. The intramembrane microarchitectures and CO2/N2 separation performance were evaluated by SEM, EDS, XRD, N2 sorption/desorption, FTIR, TGA, DSC and home-made gas permeability measurements. The optimal performance could be observed in ZIF-67-L/Pebax MMMs with 10 wt% loading under pure gas test conditions, compared with the neat Pebax membrane, the CO2 permeability and ideal CO2/N2 selectivity were improved by 74.1% and 23.6%, respectively. As a consequence, the present work provides rational suggestions for constructing selective microarchitecture in MMMs under CO2 capture scenarios and other membrane separation scenarios.

Constructing low-resistance and high-selectivity transport multi-channels in mixed matrix membranes for efficient CO2 separation

Conventional two-dimensional (2D) fillers in membranes have undesirable gas transport resistance owing to their interfacial barriers. In this work, 2D microporous carbon nanoplates (MCNs) were proposed to construct low-resistance and high-selectivity gas transport channels in mixed-matrix membranes (MMMs) to enhance the CO2 separation performance. MCNs were synthesized using a phase-transition material as a removable template and incorporated with Pebax-1657 to prepare MMMs. Micropores measuring 0.58 nm in the MCNs provided low-resistance CO2 diffusion channels that significantly improved CO2 permeability, as confirmed by the diffusion coefficient calculated through molecular simulation. Meanwhile, the random and effective stacking of the MCNs in the MMMs created highly selective gas transport channels that dramatically enhanced CO2/N2 selectivity. The MMMs with 0.5 wt% MCNs showed the best separation performance. In the mixed-gas test, the CO2 permeability reached 160.69 Barrer, and the CO2/N2 selectivity reached 61.2. In the pure-gas test, the CO2 permeability and CO2/N2 selectivity were 123 Barrer and 76, exhibiting distinct increases of 53.0% and 28.8% compared to those of the pristine Pebax membrane. Notably, the best CO2 separation performance of the prepared MMMs exceeded Robeson's upper bound. The proposed template-removal 2D MCNs with low-resistance and high-selectivity transport multi-channels facilitate a new process for molecularly selective and energy-efficient CO2 separation.

Water Adsorption Effect on Carbon Molecular Sieve Membranes in H2-CH4 Mixture at High Pressure

Carbon molecular sieve membranes (CMSMs) are emerging as promising solution to overcome the drawbacks of Pd-based membranes for H2 separation since (i) they are relatively easy to manufacture; (ii) they have low production and raw material costs; (iii) and they can work at conditions where polymeric and palladium membranes are not stable. In this work CMSMs have been investigated in pure gas and gas mixture tests for a proper understanding of the permeation mechanism, selectivity and purity towards hydrogen. No mass transfer limitations have been observed with these membranes, which represents an important advantage compared to Pd-Ag membranes, which suffer from concentration polarization especially at high pressure and low hydrogen concentrations. H2, CH4, CO2 and N2 permeation at high pressures and different temperatures in presence of dry and humidified stream (from ambient and water vapour) have been carried out to investigate the effect of the presence of water in the feed stream. Diffusion is the main mechanism observed for hydrogen, while methane, nitrogen and especially carbon dioxide permeate through adsorption-diffusion at low temperatures and high pressures. Finally, H2 permeation from H2-CH4 mixtures in presence of water has been compared at different temperatures and pressure, which demonstrates that water adsorption is an essential parameter to improve the performance of carbon molecular sieve membranes, especially when working at high temperature. Indeed, a hydrogen purity of 98.95% from 10% H2—90% CH4 was achieved. The main aim of this work is to understand the permeation mechanisms of CMSMs in different operating conditions and find the best conditions to optimize the separation of hydrogen.

New high permeable polysulfone/ionic liquid membrane for gas separation

In this study, the effects of 1-Ethyl-3-methylimidazolium tetrafluoroborate ionic liquid on CO2/CH4 separation performance of symmetric polysulfone membranes are investigated. Pure polysulfone membrane and ionic liquid-containing membranes are characterized. Field emission scanning electron microscopy (FE-SEM) is used to analyze surface morphology and thickness of the fabricated membranes. Energy dispersive spectroscopy (EDS) and elemental mapping, Fourier transform infrared (FTIR), thermal gravimetric (TGA), X-ray diffraction (XRD) and Tensile strength analyses are also conducted to characterize the prepared membranes. CO2/CH4 separation performance of the membranes are measured twice at 0.3 MPa and room temperature (25 °C). Permeability measurements confirm that increasing ionic liquid content in polymer-ionic liquid membranes leads to a growth in CO2 permeation and CO2/CH4 selectivity due to high affinity of the ionic liquid to carbon dioxide. CO2 permeation significantly increases from 4.3 Barrer (1 Barrer=10-10 cm3(STP)·cm·cm-2·s-1·cmHg-1, 1cmHg=1.333kPa) for the pure polymer membrane to 601.9 Barrer for the 30 wt% ionic liquid membrane. Also, selectivity of this membrane is improved from 8.2 to 25.8. mixed gas tests are implemented to investigate gases interaction. The results showed, the disruptive effect of CH4 molecules for CO2 permeation lead to selectivity decrement compare to pure gas test. The fabricated membranes with high ionic liquid content in this study are promising materials for industrial CO2/CH4 separation membranes.

1,3‐Propane Diamine/1,4‐Butane Diamine Cross‐linking Modification of Polyimide Membrane for Hydrogen Selective Separation: Effect of Diamine Mixture Ratio

AbstractHydrogen (H2) can be produced through biomass processing which involved lower energy requirement and production cost. It is produced as biohydrogen (bio‐H2) together with carbon dioxide in biogas so it is essential to purify H2 for utilization. Membrane gas separation is a promising technology for H2 purification. However, current separation efficiency of commercial polymeric membrane is insufficient to achieve industrial demand. Crosslinking diamine modification has been discovered to enhance separation performance of membrane in terms of permeability and selectivity. Gas separation effectiveness of mixed crosslinking agent on polyimide (PI) membrane is studied in this research by blending PDA and BuDA with different concentration. PI membrane is fabricated with phase inversion method with different weight percentage of PI in polymer solution. The chemical modification by immersing in mixed PDA‐BuDA crosslinking solution for 5 minutes reaction times. Pure gas test has been conducted for separation performance andchemical structure changes were monitored by FTIR. It is found that H2/CO2 selectivity increased significantly and H2 permeability decreased dramatically with higher concentration of PDA in crosslinking solution. Membrane with 8:2 ratio of PDA‐BuDA solution achieved highest H2/CO2 selectivity from 3.7 to 7.8 compared to other ratio of PDA‐BuDA solution.

Highly CO2 selective chitosan/g-C3N4/ZIF-8 membrane on polyethersulfone microporous substrate

Chitosan (CS) modified graphitic carbon nitride (g-C3N4)/ZIF-8/PES membrane was synthesized for enhancement in CO2/CH4 separation. The layer by layer growth method of membrane fabrication was applied for the synthesis of ZIF-8 on polyethersulfone (PES) support. The samples were characterized by XRD, gravimetric analysis of crystallinity degree, laser particle size distribution analysis (PSD) and SEM to investigate the crystal structure and morphology of ZIF-8. The FTIR and 13C NMR spectroscopies were applied to investigate the formation of possible bonds between g-C3N4 and ZIF-8 respectively. Pure gas permeation tests showed that the chitosan modified g-C3N4 incorporated ZIF-8 membranes have superior CO2/CH4 ideal selectivity (24.2) compared with pristine ZIF-8 membrane. Due to the approved formation of CN bond between g-C3N4 and imidazole group of ZIF-8, the flexibility of the modified ZIF-8 membrane increased remarkably. The mixed gas permeation test results showed the same trend of change of pure gas tests but with reduced values of CO2 and CH4 permeances and CO2/CH4 selectivities especially for CS/g-C3N4/ZIF-8 membrane due to the significant competing effect in penetration of gases in this membrane sample.

Fabrication of defect-free Matrimid® asymmetric membranes and the elevated temperature application for N2/SF6 separation

N2/SF6 mixtures have been widely used in gas-insulated equipment. Highly efficient separation approaches are urgently required to recycle SF6 from the mixtures during equipment maintenance. Gas separation with glassy polymeric membranes is regarded as a promising approach due to the great size difference between SF6 and N2 molecules. However, the common membranes are quite low permeable for N2/SF6 mixtures. In this research, the dry-wet phase inversion was customized with sectionalized air gap, i.e., dried air at upper section and humidified air at lower section, to manufacture Matrimid® asymmetric membranes in bulk with an ultrathin and defect-free selective layer. After optimization, the defect-free selective layer could be thinned to 80 nm. The pure gas test at 25 °C revealed that JN2 was increased to 2.58 GPU, and αN2/SF6 was approximately 41, very close to the value in the literature [J. Membr. Sci., 2014, 452, 311]. Without the restriction from the usual PDMS coating layer for defect-blocking, the elevated temperature operation was able to be employed to further enhance gas permeation. At 128 °C, the selectivity αN2/SF6 was maximized to 115, and the relevant JN2 is 9.0 GPU. At 200 °C, the temperature close to the allowable upper limit, JN2 was increased to 15.9 GPU, and the relevant αN2/SF6 was 97. Furthermore, the mixed-gas test demonstrated the favorable long-term stability of the customized membranes, even under the extreme running condition with pressure up to 2.0 MPaG and temperature up to 200 °C. With high efficiency and throughput under elevated temperature operation mode, the Matrimid® asymmetric membrane with ultrathin and defect-free selective layer is a promising approach for the separation and recycle of SF6 from the N2/SF6 mixtures.

Multilayer thin-film composite membranes for helium enrichment

This paper describes a novel approach to fabricate a multilayer composite membrane for recovering and enriching helium from natural gas processing using commercially available thin-film composite polyamide reverse osmosis (RO) membranes. The RO membranes, which are defective in a dry state, were caulked with different polymeric materials to seal the defects; then, the permeation and separation properties were characterized using pure and mixed gases. A benchmark (Nafion®−117) membrane was selected for its superior selectivity towards helium over carbon dioxide, and the performances of the caulked RO membranes were compared. The experimental results show that the ideal selectivity of He/CO2 in the pure gas tests is in the range 20–55, while the permeance of helium is in the range 8–40 GPU depending on the caulking material. A quaternary mixture of CH4, N2, CO2, and He was used to evaluate the separation performance of the novel membrane, which was compared with that of the benchmark membrane. This study confirms that the proposed novel approach for membrane fabrication is technically practical to recover and enrich helium from CO2-containing natural gas streams.

Thermal oxidative crosslinking of phenolphthalein-based cardo polyimides with enhanced gas permeability and selectivity

A proper increase of d-spacing after crosslinking is an effective strategy to enhance gas separation performance and anti-plasticization property of polymeric membranes. One way to achieve high chain distance is to design and prepare polymer precursors that have large side groups with crosslinkable functionality. Our previous research proved that the decarboxylation crosslinked polyimides connected by a biphenyl group showed enlarged d-spacing. However, the 100% crosslinking temperature is 425–450°C that is higher than the glass transition temperature (Tg) of most polymers and may cause problem for preparing asymmetric crosslink membranes. Here we proposed a thermal oxidative crosslinking method which had a lower crosslinking temperature than the decarboxylation crosslinking method. Specifically, we synthesized two phenolphthalein-based cardo diamines, MPP and PP, with or without CH3 substituted groups and prepared the 6FDA-MPP and 6FDA-PP polyimides. The lactone ring in the cardo moiety decomposed and the crosslinking reaction took place by heating the polymer in an air purge atmosphere. A 100% conversion of the crosslinking reaction was obtained at 400°C. In addition, the crosslinked polyimides showed increased d-spacing, high CO2 permeability and CO2/CH4 selectivity than before. The best result for pure gas test was achieved for 6FDA-MPP-400, which had a CO2 permeability of 193.8 Barrer with a CO2/CH4 ideal selectivity of 39.2. No plasticization was observed for the 6FDA-MPP-400 and 6FDA-PP-400 polyimides at a CO2 pressure up to 450psia. In addition, both 6FDA-MPP-400 and 6FDA-PP-400 showed excellent mixed gas selectivity of 35 at a partial CO2 pressure of 147psia.

Boron-embedded hydrolyzed PIM-1 carbon membranes for synergistic ethylene/ethane purification

For the first time, boron embedded carbon membranes have shown superior C2H4 permeability and C2H4/C2H6 selectivity to the upper bound line under both pure and mixed gas tests. The precursors of the carbon membranes were prepared by incorporating various boron compounds with different molecular sizes into a hydrolyzed polymer of intrinsic microporosity (PIM-1) and then carbonized at 700°C. The increments in C2H4 permeability and C2H4/C2H6 selectivity followed the order of molecular size of the boron compounds. Both PALS results and CO2 adsorption isotherms confirmed the enlarged pore size and increased pore amount. The enhancements in C2H4 permeability and C2H4/C2H6 selectivity were mainly due to the higher C2H4 diffusivity and greater diffusion selectivity resulting from proper choices of boron additives and carbonization conditions. When 9,9-dihexylfluorene-2,7-diboronic acid (DHFDA) was embedded into the hydrolyzed PIM-1 and then carbonized at 700°C, the C2H4 permeability and C2H4/C2H6 selectivity of the carbonized membrane under mixed gas tests increased from 7.5 to 13.7 Barrer and from 9.3 to 9.7, respectively.

Ionic liquid-modified Pebax® 1657 membrane filled by ZIF-8 particles for separation of CO2 from CH4, N2 and H2

3-Di-n-butyl-2-mthylimidazolium chloride (DnBMCl) ionic liquid (IL) was synthesized and used for modification of Pebax 1657 surface. ZIF-8 particles synthesized by different molar ratios of precursors, were introduced into the matrix of IL-Pebax 1657 for fabrication of mixed matrix membranes (MMMs) by coating method. Synthesized ZIF-8 particles were characterized using laser particle size analyzer, SEM, XRD and N2 adsorption. SEM, DSC, FTIR, 13C NMR, TGA and gas permeation tests were applied for characterization and performance evaluation of MMMs. The modification of Pebax 1657 with DnBMCl lead to formation of possible Carbon-Carbon bonds between Pebax 1657 and DnBMCl and also between ZIF-8 and DnBMCl. Pure gas permeation tests showed that the higher ideal selectivities of CO2/CH4, CO2/N2 and CO2/H2 were observed for DnBMCl-modified MMMs compared to unmodified MMMs and neat Pebax 1657 membrane. Plasticization lead to inferior CO2 separation ability of MMMs in mixed gas condition compared to pure gas test. The DnBMCl-modified Pebax 1657/ZIF-8 MMMs showed superior CO2/CH4, CO2/N2 selectivities at feed pressures of 2 and 4bar.

Effects of Pyrolysis Temperature on the Properties of Phenol-Formaldehyde Resin Based Carbon Molecular Sieve Membrane

Carbon molecular sieve membranes were prepared by pyrolysis of novolac type phenol-formaldehyde resin. The influences of pyrolysis temperature on membrane properties were investigated. By raising the pyrolysis temperature from 600 oC to 700 oC, the number of pores and effective pore size increased, thereby making the carbon membrane more productive but less selective. When the pyrolysis temperature from 700 oC to 900 oC, the effective pore size was reduced by sinter effect, thereby the gas permeation rate decreased and selectivity increased. The carbon membranes were characterized by elemental analysis, X-ray diffraction (XRD), and CO2 adsorption. H2, N2, CH4, and O2 were used for pure gas tests to evaluate membrane performance.

Modifying the molecular structure and gas separation performance of thermally labile polyimide-based membranes for enhanced natural gas purification

Thermal annealing is one of the feasible approaches to alter the molecular structure and enhance the gas separation performance of polyimide membranes for natural gas purification. In this study, annealing in air and incorporating β-CD and β-CD–ferrocene are employed to change the molecular structure and improve the CO2/CH4 gas-pair separation and stability of polyimide membranes. A 55% increment in CO2/CH4 selectivity at the expense of permeability are observed for the PI membrane annealed under air at 400°C compared to the as-cast membrane. A further twofold improvement in the permeability of the β-CD containing membrane annealed under air at 400°C is achieved. The CO2/CH4 selectivity also increases by 20%. With the inclusion of ferrocene, the membrane exhibits a decline in permeability with an improvement of CO2/CH4 selectivity to 47.3 when annealed in air at 400°C. The structural changes are elucidated by characterization techniques (TGA, XPS and gel content). The annealed membranes in air have shown improved resistance to CO2 plasticization and exhibit good mechanical strength. When subjected to a binary CO2/CH4 gas mixture, the gas separation performance remains almost unchanged compared to the pure gas tests. Membranes with high stability under binary gas tests, resistance to CO2 plasticization and strong mechanical strength are developed.

Facilitated transport by amine-mediated poly(vinyl alcohol) membranes for CO2 removal from natural gas

The drive toward greater application of membrane has resulted in its rapid development in natural gas processing industry. In this work, amine-mediated membranes were tailored for CO2 removal from CO2/CH4 stream. The effects of various parameters such as amine concentration, microporous support, feed pressure and composition were examined to study the permeation behavior of pure and mixed gases. Generally, CO2 transport through the DEA-PVA membranes was higher than that of MEA-PVA membranes for approximately 70%. The membrane containing 15 wt% DEA and 35 wt% MEA revealed higher permselectivity. CO2 permeance enhancement of amine-PVA membranes in comparison with neat PVA membrane, confirmed that CO2-amine reaction was the dominant transport mechanism. Additionally, with increasing feed pressure, CO2/CH4 permselectivity decreased due to carrier saturation. However, lower partial pressure of CO2 was in favor of reaction mechanism in pure and mixed gas tests. On the other hand, CH4 is not significantly affected by feed pressure confirming that solutiondiffusion is the governing transport mechanism. Additionally, PTFE support with higher wettability showed better performance (18%) regardless of amine type, concentration and feed pressure. DEA-PVA membrane has exhibited good stability during 2 weeks, unlike MEA-impregnated membrane, which was probably due to carrier degradation over time. POLYM. ENG. SCI., 54:1268–1279, 2014. V C 2013 Society of Plastics Engineers

Physical aging, high temperature and water vapor permeation studies of UV-rearranged PIM-1 membranes for advanced hydrogen purification and production

Ultraviolet (UV)-rearranged PIM-1 membranes have been shown to exhibit superior gas separation performance for H2/CO2 separation. The long-term aging studies of up to 100 days were investigated and revealed that the UV-rearranged PIM-1 membranes are much more stable than the original PIM-1 membrane. By positron annihilation lifetime (PAL) analyses, a constant decrease of o-Ps lifetime during physical aging of all membranes was observed, while o-Ps intensity changed sparingly. Compared to pure gas tests, the UV-irradiated PIM-1 membrane shows considerably enhanced separation performance in mixed gas tests with and without CO under high temperatures. Although the UV-rearranged PIM-1 membranes reveal deteriorating gas separation performance under humid feed conditions due to the effect of water vapor induced plasticization, the overall gas separation performance still outperforms most literature data. The successful validation of the separation performance for the UV-rearranged PIM-1 membranes under similar industrial testing conditions may possibly suggest the great potential of this type of membrane for the purification and production of industrial hydrogen.

The property of hydrogen separation from CO2 mixture using Pd-based membranes for carbon capture and storage (CCS)

This study investigates the module configuration for upscaling CO2 capture capacity to a bench-scale in hydrogen selective Pd-based composite membranes. In order to confirm effective upscaling, four plate-type membranes of two inch diameter were stacked in a newly designed plate-and-frame type module, reaching a total membrane surface area of 6.64 × 10−3 m2 (66.4 cm2). A pure gas test carried out using H2 and He confirmed that there were no effects of module configuration in gas permeation behavior, indicating that the upscale of the separation capacity by numbering-up of membranes using our module design was successful. The CO2 enrichment test was conducted using a 40%CO2 + 60%H2 mixture (i.e. a similar composition for the coal gasifier after both the shift reaction and H2O removal), under high feed pressure and flow rate, i.e. 600–2100 kPa and 0.48–0.72 N m3 h−1. The mixture gas test confirmed that the bench-scale membrane module could enrich 40% of the CO2 at a feed flow rate of 0.48 N m3 h−1 up to 93% with a hydrogen recovery ratio of >90% at 673 K and a total feed pressure of 2100 kPa, i.e. ∼4 times CO2 enrichment capacity of one membrane.

CO2-selective membranes for hydrogen purification and the effect of carbon monoxide (CO) on its gas separation performance

Industrial hydrogen production may prefer CO2-selective membranes because high-pressure H2 can therefore be produced without additional recompression. In this study, high performance CO2-selective membranes are fabricated by modifying a polymer–silica hybrid matrix (PSHM) with a low molecular weight poly(ethylene glycol) dimethyl ether (PEGDME). The liquid state of PEGDME and its unique end groups eliminate the crystallization tendency of poly(ethylene glycol) (PEG). The methyl end groups in PEGDME hinder hydrogen bonding between the polymer chains and significantly enhance the gas diffusivity. In pure gas tests, the membrane containing 50 wt% additive shows CO2 gas permeability and CO2/H2 selectivity of 1637Barrers and 13 at 35°C, respectively. In order to explore the effect of real industrial conditions, the gas separation performance of the newly developed membranes has been studied extensively using binary (CO2/H2) and ternary gas mixtures (CO2/H2/carbon monoxide (CO)). Compared to pure gas performance, the second component (H2) in the binary mixed gas test reduces the CO2 permeability. The presence of CO in the feed gas stream decreases both CO2 and H2 permeability as well as CO2/H2 selectivity as it reduces the concentration of CO2 molecules in the polymer matrix. The mixed gas results affirm the promising applications of the newly developed membranes for H2 purification.