The Carbon Molecular Sieve Membranes. General Properties and the Permeability of CH<sub>4</sub>/H<sub>2</sub>Mixture

Koresh, Jacob E.; Soffer, Abrah

doi:10.1080/01496398708068993

Cited by 182 publications

(70 citation statements)

References 14 publications

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“…The gas separation performance of carbon membranes depends on the critical pore size and pore size distribution. The openings contribute to the major part of the pore volume and are thus responsible for the adsorption capacity, while the constrictions are responsible for the selectivity [10]. The pores in carbon membranes are formed by packing imperfections be-tween ordered regions in the material and are described as slit-like with an idealized bimodal pore size distribution.…”

Section: Introductionmentioning

confidence: 99%

Composite-alumina-carbon molecular sieve membranes prepared from novolac resin and boehmite. Part I: Preparation, characterization and gas permeation studies

Tanco

Tanaka

Rodrigues

et al. 2015

International Journal of Hydrogen Energy

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Supported composite alumina-carbon molecular sieve membranes (c-CMSM) were prepared from in house prepared novolac phenolic resin loaded with boehmite nanoparticles in a single dipping-drying-carbonization step. A porous a-alumina tube support was dipped into a N-methyl-2-pyrrolidone solution containing polymerized novolac resin loaded with boehmite, subsequently dried at 100 o C and carbonized at 500 o C under nitrogen environment. The structure, morphology and performance of the membranes were examined by scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), carbon dioxide adsorption and permeation of N2, O2, He, H2 and CO2. SEM showed carbon membranes with a thin and very uniform layer with a thickness of ca. 3 m CO2 adsorption isotherms indicated that the produced carbon membranes presented a micro-porous structure. The c-CMSM exhibited good gas separation properties. The permselectivity surpass the Robeson upper bound for polymeric membranes, especially regarding ideal permselectivities of pairs H2/N2 = 117, and He/O2 = 49. Aging effects were observed after membrane exposure to ambient air.However with a thermal treatment under nitrogen atmosphere the permeance of nitrogen increases.

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Section: Introductionmentioning

confidence: 99%

Composite-alumina-carbon molecular sieve membranes prepared from novolac resin and boehmite. Part I: Preparation, characterization and gas permeation studies

Tanco

Tanaka

Rodrigues

et al. 2015

International Journal of Hydrogen Energy

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“…CMSMs are highly porous materials and possess the distribution of small selective pores which similar to the dimension of diffusing gas molecules in the order of 3-6 A [2,14,15]. Selective adsorption and molecular sieving are the main mechanisms involved in the carbon membrane separation.…”

Section: Introductionmentioning

confidence: 99%

Novel approaches to fabricate carbon molecular sieve membranes based on chemical modified and solvent treated polyimides

Tin

Chung

Kawi

et al. 2004

Microporous and Mesoporous Materials

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Novel approaches to fabricate carbon molecular sieve membranes based on chemical modified and solvent treated polyimides Tin, P.; Chung, T-S.; Kawi, S.; Guiver, Michael AbstractTwo brand-new modification technologies were developed for pyrolyzing the carbon molecular sieve membranes (CMSMs) with excellent separation efficiency. The modifications were performed on polymeric precursors. It is believed that the space filling effect by these modifications could considerably alter the separation performance of resultant carbon membranes. Firstly, a cross-linking modification was performed on polymeric precursors at room temperature before pyrolysis. The effectiveness of chemical crosslinking technology in improving gas separation capability of CMSMs was investigated. In this study, the permeation properties of carbon membranes derived from cross-linked Matrimid were characterized as a function of cross-linking density. Results demonstrated that the permeability of modified CMSMs decreased with increasing in cross-linking density. Detailed examination reveals that cross-linking modification increased the selectivity at a low degree of cross-linking but reduced the selectivity at a higher degree of cross-linking. The improvement of separation efficiency at low degree of cross-linking is presumably related to the swelling of polymer chains by methanol during cross-linking modification. Consequently, the second extremely simple modification method by using pure methanol immersion was developed. It was found that the CMSMs derived from methanol-treated precursors exhibited superior transport properties. Methanol treatment yielded CMSMs with higher selectivities if compared to CMSMs based on untreated and cross-linked Matrimid. Therefore, it can be concluded that the swelling of polymer chains by methanol appears to be an effectual modification method to produce the CMSMs with excellent separation properties.

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“…Hollow-fiber carbon membranes were first reported by Koresh and Soffer,10 who articulated the main advantages of carbon membranes relative to polymeric membranes. These first membranes were made from cellulosic-fiber precursors.…”

Section: Hollow-fiber (Unsupported) Membranesmentioning

confidence: 99%

Synthesis of Porous Inorganic Membranes

Tsapatsis¹,

Gavalas²

1999

MRS Bull.

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Here we will attempt a brief overview of recent synthetic efforts for micropore and lower-end mesopore membranes. We will not address the very important classes of nonporous membranes, such as dense metals and solid electrolytes with applications in H2 and O2 separations, or meso- and macroporous membranes, which find applications in food processing and water treatment. Microporous materials provide high permselectivities for molecules encountered in the chemical-processing industry but suffer from low intrinsic permeabilities. Therefore, in order to bring microporous membrane materials to commercial applications, functional composites with small effective thicknesses (in the micron or submicron range) must be developed. For example, to achieve economical membrane-reactor sizes, fluxes as high as 0.1 mol/(m2 s) are desirable. Approaches to microporous membranes include modification of mesoporous membranes by sol-gel and chemical-vapor-deposition (CVD) techniques, carbonization of polymers to form molecular-sieve carbon, and polycrystalline-film growth of zeolites and other molecular sieves.Microporous carbon is widely used for liquid or gas purification because of its strong adsorptive properties and high surface area. It is also used for air separation by pressure swing adsorption (PSA), relying on its adsorptive and molecular-sieving properties. From the standpoint of applications, microporous carbons are classified into activated carbons with pore size 0.8–2 nm, and ultramicroporous carbons or carbon molecular sieves with pores 0.3–0.6 nm. Activated carbons are used because of their strong adsorption properties, while carbon molecular sieves are useful on account of their molecular-sieving as well as adsorption properties.

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The Carbon Molecular Sieve Membranes. General Properties and the Permeability of CH₄/H₂Mixture

Cited by 182 publications

References 14 publications

Composite-alumina-carbon molecular sieve membranes prepared from novolac resin and boehmite. Part I: Preparation, characterization and gas permeation studies

Composite-alumina-carbon molecular sieve membranes prepared from novolac resin and boehmite. Part I: Preparation, characterization and gas permeation studies

Novel approaches to fabricate carbon molecular sieve membranes based on chemical modified and solvent treated polyimides

Synthesis of Porous Inorganic Membranes

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The Carbon Molecular Sieve Membranes. General Properties and the Permeability of CH4/H2Mixture

Cited by 182 publications

References 14 publications

Composite-alumina-carbon molecular sieve membranes prepared from novolac resin and boehmite. Part I: Preparation, characterization and gas permeation studies

Composite-alumina-carbon molecular sieve membranes prepared from novolac resin and boehmite. Part I: Preparation, characterization and gas permeation studies

Novel approaches to fabricate carbon molecular sieve membranes based on chemical modified and solvent treated polyimides

Synthesis of Porous Inorganic Membranes

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The Carbon Molecular Sieve Membranes. General Properties and the Permeability of CH₄/H₂Mixture