Effect of polyethyleneglycol (PEG) on gas permeabilities and permselectivities in its cellulose acetate (CA) blend membranes

The effect of polyethyleneglycol (PEG) on gas permeabilities and selectivities was investigated in a series of miscible cellulose acetate (CA) blend membranes. The permeabilities of CO₂, H₂, O₂, CH₄, N₂ were measured at temperatures from 30 to 80°C and pressures from 20 to 76 cmHg using a manometric permeation apparatus. It was determined that the blend membrane having 10 wt% PEG20000 exhibited higher permeability for CO₂ and higher permselectivity for CO₂ over N₂ and CH₄ than those of the membranes which contained 10% PEG of the molecular weight in the range 200–6000. The CA blend containing 60 wt% PEG20000 showed that its permeability coefficients of CO₂ and ideal separation factors for CO₂ over N₂ reached above 2 × 10⁻⁸ [cm³ (STP) cm/cm² s cmHg] and 22, respectively, at 70°C and 20 cmHg. Based on the data of gas permeability coefficients, time lags and characterization of the membranes, it is proposed that the apparent solubility coefficients of all CA and PEG blend membranes for CO₂ were lower than those of the CA membrane. However, almost all the blend membranes containing PEG20000 showed higher apparent diffusivity coefficients for CO₂, resulting in higher permeability coefficients of CO₂ with relation to those of the CA membrane. It is attributed to the high diffusivity selectivities of CA and PEG20000 blend membranes that their ideal separation factors for CO₂ over N₂ were higher than those of the CA membrane in the range 50–80°C, even though the ideal separation factors of almost all PEG blend membranes for CO₂ over CH₄ became lower than those of the CA membrane over nearly the full range from 30° to 80°C.     

Pebax/poly(vinyl alcohol) mixed matrix membrane incorporated by amine-functionalized graphene oxide for CO2 separation

Graphene oxide nanoparticles (GO) were firstly functionalized using p-phenylenediamine and then utilized as nanofillers to prepare poly(ether-block-amide) (Pebax®-1657)/poly(vinyl alcohol) (PVA-60000)-based mixed-matrix membranes. The modified GO as well as the fabricated mixed matrix membranes underwent some characterization analyses, including FTIR, TGA, XRD, FESEM, and EDX. The influence of amine-modified nanoparticles content (2, 4, and 6 wt%), and feed pressure on CO₂, CH₄, and N₂ permeabilitis and ideal CO₂/CH₄ and CO₂/N₂ selectivities values of the MMMs were investigated. The permeation experiments demonstrated that Pebax/PVA (10 and 15 wt%) blend membranes caused an increase in CO₂ permeability owing to the high affinity of polar CO₂ molecules to polar PVA segments. Moreover, the incorporation of 6 wt% amine-functionalized GO into the Pebax/PVA (10 wt%) and Pebax/PVA (15 wt%) blend polymer raised the CO₂ permeability and CO₂/CH₄ and CO₂/N₂ selectivity by nearly 43%, 28%, and 37%, respectively, due to the higher CO₂ adsorption capacity of the amine-functionalized GO.     

Effective enhancement of selectivities and capacities for CO2 over CH4 and N2 of polymers of intrinsic microporosity via postsynthesis metalation

A series of metalized C-PIM-M (M = Na⁺, Mg²⁺, Al³⁺, PIMs = polymers of intrinsic microporosity) materials were prepared from a carboxyl-functionalized PIM (C-PIMs). The C-PIM-Na exhibited a high CO₂ adsorption capacity of 2.44 mmol/g and extreme low CH₄ uptake of 0.28 mmol/g at 273 K and 101 kPa among three metallated PIMs. It showed remarkably high CO₂/CH₄ and CO₂/N₂ selectivities at both 273 and 293 K due to an advantageous pore-blocking effect of Na⁺ cation.     

Carbon dioxide sequestration and methane removal from exhaust gases using resorcinol–formaldehyde activated carbon xerogel

The world is faced with intrinsic environmental issues. Among these issues, the minimization of greenhouse gas emission to acceptable levels presents a high priority. This study seeks to help to reduce the greenhouse effect in sustainable manner. A resorcinol–formaldehyde xerogel was synthesized at specific conditions and used to prepare an activated carbon xerogel (RF-ACX). RF-ACX exhibited micropores in range of 1.2–1.4 nm, a surface area of 496 m²/g and a cumulative pore volume of 0.81 cm³/g. Scanning electron microscopy showed that it is made of microspherical particles with an almost uniform particle size of 1.3 ± 0.2 μm. Equilibrium and kinetic studies for the adsorption of CO₂, CH₄ and N₂ on RF-ACX were conducted at five temperatures (293, 303, 313, 323, and 333 K) and pressures of up to 1 MPa. The adsorption capacity on RF-ACX was highest for CO₂, followed by CH₄ and then N₂. Isosteric heats of adsorption and adsorption rates were investigated. The measured adsorption equilibria were fitted with the extended multisite Langmuir adsorption model and further used to predict adsorption equilibria of their corresponding binary systems.     

An Hetero‐Epitaxially Grown Zeolite Membrane

The secondary growth methodology to form zeolite membranes has stringent requirements for homogeneous epitaxial intergrowth of the seed layer and limits the number of accessible high‐quality zeolite membranes. Despite previous reports on hetero‐epitaxial growth, high‐performance zeolite membranes have yet to be reported using this approach. Here, the successful hetero‐epitaxial growth of highly siliceous ZSM‐58 (DDR‐type zeolite) films from a SSZ‐13 (CHA‐type zeolite) seed layer is reported. The resulting membranes show excellent CO₂ perm‐selectivities, having maximum CO₂ /N₂ and CO₂ /CH₄ separation factors (SFs) as high as about 17 and 279, respectively, at 30 °C. Furthermore, the hybrid membrane maintains the CO₂ perm‐selectivity in the presence of water vapor (the third main component in both cases), that is, CO₂ /N₂ SF of about 14 and CO₂ /CH₄ SF of about 78, respectively, at 50 °C (a representative temperature of both CO₂‐containing streams).     

A flexible metal-organic framework with double interpenetration for highly selective CO2 capture at room temperature

A flexible metal-organic framework of 1a Cu(FMA)(4,4'-Bpe)0.5(FMA=fumarate; 4,4'-Bpe=trans-bis-(4-pyridyl)ethylene) that exhibits guest molecule-controlled gate-opening adsorption has been reported, in which the flexible pores can be enlarged by CO_2 molecules rather than CH_4 and N_2 under a certain gate-opening pressure. The CO_2 uptake can be sharply improved from 6.85cm~3 g~(–1) at 0.60 atm to 33.7 cm~3 g~(–1) at 1 atm due to the gate-opening effect, thus resulting in the notably enhanced adsorption selectivities for CO_2/CH_4(32:1, v/v) and CO_2/N_2(48:1, v/v) separations at room temperature.     

源自密胺基多孔聚合物的富氮微孔炭及选择性吸附CO_2

以间苯二甲醛和三聚氰胺为原料,通过Schiff碱缩合反应合成了密胺基多孔聚合物(POP),经高温炭化后得到富氮微孔炭(NMC).利用N2吸脱附和傅里叶变换红外(FTIR)光谱表征了POP和炭化后产物NMC的结构和组成,与POP相比,NMC的官能团数量减少,比表面积和微孔孔容大幅增加.元素分析表明NMC含氮量高达12.5%(w).采用体积法测定了CO2、CH4和N2在NMC上的单组分吸附平衡等温线,NMC展示出良好的CO2吸附性能,298 K、100 kPa下CO2平衡吸附量可达2.34 mmol·g-1.双位Langmuir(DSL)模型和单位Langmuir(SSL)模型分别较好地描述了CO2、CH4和N2在NMC上的吸附平衡数据,在此基础上,应用理想吸附溶液理论(IAST)预测了双组分混合气在NMC上的吸附等温线,结果表明NMC对CO2-N2和CO2-CH4有非常高的CO2吸附选择性,分别为144.9和12.8.     

Microporous Poly(Schiff Base) Constructed from Tetraphenyladamantane Units for Adsorption of Gases and Organic Vapors

A new microporous poly(Schiff base) ( PSN‐3 ) is constructed from 1,3,5,7‐tetrakis(4‐formylphenyl)adamantane and 1,3,5,7‐tetrakis(4‐aminophenyl)adamantane through an A₄‐A₄′ reaction. The surface and internal morphologies of porous PSN‐3 are examined by FE‐SEM and HR‐TEM. PSN‐3 exhibits a BET surface area of 865 m² g⁻¹ with a major pore size around 0.6 nm. Moreover, PSN‐3 can uptake 1.32 wt% H₂ (77 K/1 bar), 13.6 wt% CO₂ (273 K/1 bar), 80.5 wt% benzene, and 63.7 wt% cyclohexane (298 K/0.9 bar). The adsorption selectivities for CO₂/N₂, CO₂/CH₄, benzene/N₂, and benzene/H₂O are 88, 16, 267, and 19, respectively. The high adsorption capacities and selectivities for gases and vapors make PSN‐3 a promising candidate for H₂ storage, CO₂ capture, and recovery of organic pollutants.

     

Gas transport properties of poly(ether‐b‐amide) segmented block copolymers

The permeation properties of H₂, N₂, and CO₂ were determined at 35 °C and pressures up to 15 atm in phase‐separated polyether‐b‐polyamide segmented block copolymers. These polymers contain poly(ethylene oxide) [PEO] or poly(tetramethylene oxide) [PTMEO] as the rubbery polyether phase and nylon‐6 [PA6] or nylon‐12 [PA12] as the hard polyamide phase. Extremely high values of polar (or quadrupolar)/nonpolar gas selectivities, coupled with high CO₂ permeability coefficients, were observed. CO₂/H₂ selectivities as high as 9.8 and CO₂/N₂ selectivities as high as 56 were obtained in polymers with CO₂ permeability coefficients of approximately 220 × 10⁻¹⁰ cm³(STP) cm/(cm² s cmHg). As the amount of polyether increases, permeability increases. Gas permeability is higher in polymers with less polar constituents, PTMEO and PA12, than in those containing the more polar PEO and PA6 units. CO₂/N₂ and CO₂/H₂ selectivities are higher in polymers with higher concentrations of polar groups. These high selectivity values derive from large solubility selectivities in favor of CO₂. Because CO₂ is larger than H₂ and has, therefore, a lower diffusion coefficient than H₂, the weak size‐sieving ability of the rubbery polyether phase, which is the locus of most of the gas permeation, also contributes to high CO₂/H₂ selectivity. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 2051–2062, 2000     

Tailoring microporosity and nitrogen content in carbons for achieving high uptake of CO2 at ambient conditions

A series of nitrogen-containing carbon spheres (CS) was prepared using the modified Stöber method. These CS were synthesized by using resorcinol and formaldehyde as carbon precursors, melamine as nitrogen precursor and ammonia as a polymerization reaction catalyst. Hydrothermal treatment followed by activation of these polymer spheres resulted in highly porous nitrogen-containing CS. Elemental analysis and N₂ adsorption showed that the aforementioned CS exhibited high surface area (reaching 1,610 m²/g) with large fraction of fine micropores (volume of micropores smaller than 1 nm was estimated to be 0.40 cm³/g) and comparatively high nitrogen content (about 4.0 at.%). Interestingly, high CO₂ adsorption capacities, 4.4 and 6.9 mmol/g, were obtained for these CS at 1 bar and two temperatures, 25 and 0 °C, respectively.     

Synthesis, characterization, and gas permeation properties of 6FDA-2,6-DAT/mPDA copolyimides

The goal of this work is to explore new polyimide materials that exhibit both high permeability and high selectivity for specific gases. Copolyimides offer the possibility of preparing membranes with gas permeabilities and selectivities not obtainable with homopolyimides. A series of novel fluorinated copolyimides were synthesized with various diamine compositions by chemical imidization in a two-pot procedure. Polyamic acids were prepared by stoichiometric addition of solid dianhydride in portions to the diamine(s). The gas permeation behavior of 2,2′-bis(3,4′-dicarboxyphenyl) hexafluoropropane dianhydride(6FDA)-2,6-diamine toluene (2,6-DAT)/1,3-phenylenediamine (mPDA) polyimides was investigated. The physical properties of the copolyimides were characterized by IR, DSC and TGA. The glass transition temperature increased with increase in 2,6-DAT content. All the copolyimides were soluble in most of the common solvents. The gas permeability coefficients decreased with increasing mPDA content. However, the permselectivity of gas pairs such as H₂/N₂, O₂/N₂, and CO₂/CH₄ was enhanced with the incorporation of mPDA moiety. The permeability coefficients of H₂, O₂, N₂, CO₂ and CH₄ were found to decrease with the increasing order of kinetic diameters of the penetrant gases. 6FDA-2,6-DAT/mPDA (3:1) copolyimide and 6FDA-2,6-DAT polyimide had high separation properties for H₂/N₂, O₂/N₂, CO₂/CH₄. Their H₂, O₂ and CO₂ permeability coefficients were 64.99 Barrer, 5.22 Barrer, 23.87 Barrer and 81.96 Barrer, 8.83 Barrer, 39.59 Barrer, respectively, at 35°C and 0.2 MPa (1 Barrer = 10⁻¹⁰ cm³ (STP)·cm·cm⁻²·s⁻¹·cmHg⁻¹) and their ideal permselectivities of H₂/N₂, O₂/N₂ and CO₂/CH₄ were 69.61, 6.09, 63.92 and 53.45, 5.76, 57.41, respectively. Moreover, all of the copolyimides studied in this work exhibited similar performance, lying on or above the existing upper bound trade-off lines between permselectivity and permeability. They may be utilized for commercial gas separation membrane materials. __________ Translated from Acta Polymerica Sinica, 2008, 8 (in Chinese)     

Adsorption separation of carbon dioxide,methane, and nitrogen on Hβ and Na-exchanged β-zeolite

Adsorption isotherms of carbon dioxide （CO2）, methane （CH4）, and nitrogen （N2） on Hβand sodium exchanged β-zeolite （Naβ） were volumetrically measured at 273 and 303 K. The results show that all isotherms were of Brunauer type I and well correlated with Langmuir-Freundlich model. After sodium ions exchange, the adsorption amounts of three adsorbates increased, while the increase magnitude of CO2 adsorption capacity was much higher than that of CH4 and N2. The selectivities of CO2 over CH4 and CO2 over N2 enhanced after sodium exchange. Also, the initial heat of adsorption data implied a stronger interaction of CO2 molecules with Na＋ ions in Naβ . These results can be attributed to the larger electrostatic interaction of CO2 with extraframework cations in zeolites. However, Naβ showed a decrease in the selectivity of CH4 over N2, which can be ascribed to the moderate affinity of N2 with Naβ. The variation of isosteric heats of adsorption as a function of loading indicates that the adsorption of CO2 in Naβ presents an energetically heterogeneous profile. On the contrary, the adsorption of CH4 was found to be essentially homogeneous, which suggests the dispersion interaction between CH4 and lattice oxygen atoms, and such interaction does not depend on the exchangeable cations of zeolite.     

One‐stage Template‐free KOH Activation for Mesopore‐enriched Carbons and Their Application in CO2 Capture

Activated carbons with a high mesoporous structure were prepared by a one‐stage KOH activation process without the assistance of templates and further used as adsorbents for CO₂ capture. The physical and chemical properties as well as the pore structures of the resulting mesoporous carbons were characterized by N₂ adsorption isotherms, scanning electron microscopy (SEM ), X‐ray diffraction (XRD ), Raman spectroscopy, and Fourier transform infrared (FTIR ) spectroscopy. The activated carbon showed greater specific surface area and mesopore volume as the activation temperature was increased up to 600°C, showing a uniform pore structure, great surface area (up to ~815 m²/g), and high mesopore ratio (~55%). The activated sample exhibited competitive CO₂ adsorption capacities at 1 atm pressure, reaching 2.29 and 3.4 mmol/g at 25 and 0°C, respectively. This study highlights the potential of well‐designed mesoporous carbon as an adsorbent for CO₂ removal and widespread gas adsorption applications.     

Structure/permeability relationships of polyimide membranes. Applications to the separation of gas mixtures

The permeability of nine different polyimide membranes to H₂, N₂, O₂, CH₄, and CO₂ has been determined at 35°C and at applied pressures of up to 9 atm. The dianhydride monomers used for the synthesis of the polymides were PMDA and 6FDA, whereas the diamine monomers were ODA, BDAF, and p-PDA. The selectivities of the 6FDA polymides toward CO₂ relative to CH₄ are higher than those of the PMDA polyimides at comparable CO₂ permeabilities. Both types of polyimides exhibit significantly higher CO₂/CH₄ selectivities than more common glassy polymers, such as cellulose acetate, polysulfone, and polycarbonate. The selectivities of the PMDA and 6FDA polyimides to O₂ relative to N₂ are of the same magnitude and generally higher than those of common glassy polymers with similar O₂ permeabilities. The polymides are more permeable to N₂ than to CH₄, whereas the opposite is true for many other glassy polymers. Possible factors responsible for the above behavior, such as segmental mobility, mean interchain distance, and formation of charge transfer complexes, are examined. The relevance of the study to the development of more highly gas-selective and permeable membranes for the separation of gas mixtures is also discussed.     

High performance of PES-GNs MMMs for gas separation and selectivity

In this study, graphene nanosheets (GNs) were incorporated into polyethersulfone (PES) by phase inversion approach for preparing PES-GNs mixed matrix membranes (MMMs). To investigate the impact of filler content on membrane surface morphology, thermal stability, chemical composition, porosity and mechanical properties, MMMs were constructed with various GNs loadings (0.01, 0.02, 0.03, and 0.04 wt%). ?The performance of prepared MMMs was tested for separation and selectivity of CO₂, N₂, H₂ and CH₄ gases at various pressures from 1 to 6 bar and temperature varying from 20 to 60 °C. It was observed that, compared to the pristine PES membrane, the prepared MMMs significantly improved the gas separation and selectivity performance with adequate mechanical stability. The permeability of CO₂, N₂, H₂ and CH₄ for the PES + 0.04 wt% GNs increases from 9 to 2246, 11 to 2235, 9 to 7151, and 3 to 4176 Barrer respectively, as compared with pure PES membrane at 1 bar and 20 °C due to improving the membrane absorption and porosity. In addition, by increasing the pressure, the permeability and selectivity of CO₂, N₂, H₂ and CH₄ are increased due to the increased driving force for the transport of gas via membranes. Furthermore, the permeability of CO₂, N₂, H₂ and CH₄ increased by increasing the temperature from 20 to 60 °C due to the plasticization in the membranes and the improvement in polymer chain movement. This result proved that the prepared membranes can be used for gas separation applications.     

Hydrogen production from bio-oil by chemical looping reforming

Hydrogen is a green energy carrier. Chemical looping reforming of biomass and its derivatives is a promising way for hydrogen production. However, the removal of carbon dioxide is costly and inefficient with the traditional chemical absorption methods. The objective of this article is to find a new material with low energy consumption and high capacity for carbon dioxide storage. A metal organic framework (MOF) material (e.g., CuBTC) was prepared using the hydrothermal synthesis method. The synthesized material was characterized by X-ray diffraction, ?196 °C N₂ adsorption/desorption isotherms, and thermogravimetry analysis to obtain its physical properties. Then BET, t-plot, and density functional theory (DFT) methods were used to acquire its specific surface area and pore textural properties. Its carbon dioxide adsorption capacity was evaluated using a micromeritics ASAP 2000 instrument. The results show that the decomposition temperature of the synthesized CuBTC material is 300 °C. Besides, high CO₂ adsorption capacity (4 mmol g^?1) and low N₂ adsorption capacity were obtained at 0 °C and atmospheric pressure. These results indicate that the synthesized MOF material has a high efficiency for CO₂ separation. From this study, it is expected that this MOF material could be used in adsorption and separation of carbon dioxide in chemical looping reforming process for hydrogen production in the near future.     

Thermoregulated Phase‐Transition Synthesis of Two‐Dimensional Carbon Nanoplates Rich in sp2 Carbon and Unimodal Ultramicropores for Kinetic Gas Separation

The development of highly selective, chemically stable and moisture‐resistant adsorbents is a key milestone for gas separation. Porous carbons featured with random orientation and cross‐linking of turbostratic nanodomains usually have a wide distribution of micropores. Here we have developed a thermoregulated phase‐transition‐assisted synthesis of carbon nanoplates with more than 80 % sp² carbon, unimodal ultramicropore and a controllable thickness. The thin structure allows oriented growth of carbon crystallites, and stacking of crystallites in nearly parallel orientation are responsible for the single size of the micropores. When used for gas separation from CH₄, carbon nanoplates exhibit high uptakes (5.2, 5.3 and 5.1 mmol g^?1) and selectivities (7, 71 and 386) for CO₂, C₂H₆ and C₃H₈ under ambient conditions. The dynamic adsorption capacities are close to equilibrium uptakes of single components, further demonstrating superiority of carbon nanoplates in terms of selectivity and sorption kinetics.     

Co3(HCOO)6 microporous metal-organic framework membrane for separation of CO2/CH4 mixtures

Continuous metal–organic framework‐type Co₃(HCOO)₆ intergrown films with a one‐dimensional zigzag channel system and pore aperture of 5.5 Å are prepared by secondary growth on preseeded macroporous glass‐frit disks and silicon wafers. The adsorption behavior of CO₂ or CH₄ single gases on the Co₃(HCOO)₆ membrane is investigated by in situ IR spectroscopy. It is shown that the isosteric heats of adsorption for CO₂ (17.7 kJ mol^?1) and CH₄ (14.4 kJ mol^?1) do not vary with increasing amount of adsorbed gases. The higher value of isosteric heat for CO₂ is an indication of the stronger interaction between the CO₂ and the Co₃(HCOO)₆ membrane. The Co₃(HCOO)₆ membrane is studied by binary gas permeation of CO₂ and CH₄ at different temperatures (0, 25, and 60 °C). The membrane has CO₂/CH₄ selectivity with a separation factor higher than 10, which is due to the unique structure and molecular sieving effect. Upon increasing the temperature from 0 to 60 °C, the preferred permeance of CO₂ over CH₄ is increased from 1.70×10^?6 to 2.09×10^?6 mol m^?2 s^?1 Pa^?1, while the separation factor for CO₂/CH₄ shows a corresponding decrease from 15.95 to 10.37. The effective pore size of the Co₃(HCOO)₆ material combined with the pore shape do not allow the two molecules to pass simultaneously, and once the CO₂ molecules are diffused in the micropores, the CH₄ is blocked. The supported Co₃(HCOO)₆ membrane retains high mechanical stability after a number of thermal cycles.     

Preparation of CO_2 selective composite membranes using Pebax/CuBTC/PEG-ran-PPG ternary system

Three phase Pebax~? MH 1657/PEG-ran-PPG/CuBTC(polymer/liquid/solid) was successfully deposited as a selective layer on a porous Polysulfone(PSF) support. In fact, the beneficial properties of PEG(high selectivity) with those of PPG(high permeability, amorphous) have been combined with superior properties of mixed matrix membrane(MMMs). The membranes were characterized by DSC, TGA and SEM, while CuBTC was characterized by CO_2 and CH_4adsorption test. Statistically based experimental design(central composite design, CCD) was applied to analyze and optimize the effect of PEG-ran-PPG(10–50 wt%) and CuBTC(0–20 wt%) mass contents on the CO_2 permeance and CO_2/CH_4 ideal selectivity. Based on the regression coefficients of the obtained models, the CO_2 permeance was notably influenced by PEG-ran-PPG,while CuBTC has the most significant effect on the CO_2/CH_4 ideal selectivity. Under the optimum conditions(PEG-ran-PPG: 32.76 wt% and CuBTC: 20 wt%), nearly 620% increase in the CO_2 permeance and43% enhancement in the CO_2/CH_4 ideal selectivity was observed compared to the neat Pebax. The effect of pressure(3, 9 and 15 bar) on the pure and mixed gas separation performance of the composite membranes was also investigated. The high solubility of CO_2 in the membranes resulted in the enhancement of CO_2 permeability with increase in gas pressure.     

Influence of synthesis and operating parameters on silicalite-1 membrane properties

The present study deals with the synthesis of nanostructured silicalite-1 membranes on porous α-Al₂O₃ supports by a hydrothermal method. Different parameters including the synthesis conditions (temperature and alkalinity) and operating conditions (temperature and pressure) were investigated. The membranes were characterized by X-ray diffraction and scanning electron microscopy techniques. The optimum synthesis temperature and alkalinity were determined to be 160 °C and pH = 11, respectively. The permeability of CO₂ and CH₄ through the optimized membrane was determined by the pressure drop method. The results revealed that the main effective separation mechanism was adsorption. The permeation of CO₂ and CH₄ declined with increasing temperature, whereas high feed pressures enhanced the single gas flux. The CO₂ and CH₄ permeability values at 30 °C and 2 bar were 1.62 × 10^?7 and 2.07 × 10^?7 mol m^?2 s^?1 Pa^?1, respectively. Furthermore, the response surface methodology analysis confirmed the significance of all the variables and the proposed model. Excellent correlation between the experimental and predicted data (R² = 0.99) was obtained, confirming that response surface methodology is a powerful tool for modeling nanostructured silicalite-1 membrane processes.