Carbon–Al2O3–Ag composite molecular sieve membranes for gas separation

Teixeira, Madalena; Campo, M.C.; Tanaka, D.A. Pacheco; Tanco, Margot A. Llosa; Magén, Cesar; Mendes, Adélio

doi:10.1016/j.cherd.2012.05.016

Cited by 42 publications

(50 citation statements)

References 38 publications

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“…Ceramic substrates have been reported to provide ideal surfaces for the coating of phenolic resins, particularly porous alumina tubes which allow this technology to be scaled up. This has been shown by Pacheco Tanaka and co-workers [30][31][32][33] by coating novolac and resol phenolic resins, or by mixing alpha-alumina with novolac. A very recent development involves the preparation of carbon-alumina mixed matrix membranes, where the phenolic resin was incorporated into the porous structure of an alumina substrate by a vacuum impregnation, showing that the vacuum time played an important role in the structural formation of the mixed matrix membranes [22].…”

Section: Introductionmentioning

confidence: 81%

Vacuum-assisted tailoring of pore structures of phenolic resin derived carbon membranes

Jalil

Wang²,

Yacou

et al. 2017

Journal of Membrane Science

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This work shows the preparation and separation performance assessment of carbon membranes derived from phenolic resin by a vacuum-assisted method and carbonisation in an inert atmosphere.The vacuum time played an important role in tailoring the structure of the membranes. For instance, pore volumes and surface areas increased from 0.81 and 834 to 2.2 cm 3 g -1 and 1910 m 2 g -1 , respectively, as the vacuum time exposure increased from 0 to 1200 s. The significant structural changes correlated very well with water permeation, as fluxes increased by 91% as the vacuum time increased from 0 to 1200s, reaching up to 169 kg m -2 h -1 at 5 bar. Molecular weight cut-off tests showed no rejection for the smaller glucose and sucrose molecules, though this increased to ~ 80% and full rejection for 36kD and 400kD polyvinyl pyrrolidine. Interestingly, FTIR spectra showed that the peaks of C-H stretching vibration (2800-3200 cm -1 ) and C-O stretching (1030 cm -1 ) became more pronounced as a function of increasing vacuum time, strongly suggesting that the use of vacuum further assisted in the polycondensation of phenolic oligomers. Based on these outcomes, a cluster to cluster model is proposed, whereby vacuum application promoted crosslinking reactions of the phenolic resin, creating microporous regions within the clusters, and mesoporous regions between the clusters. 2 Graphical AbstractKeywords: carbon membranes; vacuum-assisted method; water; molecular weight cut-off.

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Section: Introductionmentioning

confidence: 81%

Vacuum-assisted tailoring of pore structures of phenolic resin derived carbon membranes

Jalil

Wang²,

Yacou

et al. 2017

Journal of Membrane Science

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“…Our group [53] had prepared supported composite-CMSMs (c-CMSMs) derived from resolphenolic resin loaded with boehmite nanoparticles in a single dippingdrying-carbonization step of a tubular a-alumina membrane sup-port. After carbonization at 550 o C a selectivity of 14 for the separation of C3H6/C3H8 was reported; the addition of silver enhanced the selectivity to 38 [54]. CMSM were also prepared varying the composition of resol and boehmite leading to the formation of c-CMSM with different carbon/Al2O3; it was found that membranes with higher carbon/Al2O3 ratio showed higher permeabilities and lower selectivities; for H2 a permeability of 2047 barrer and a selectivity for H2/N2 of 65.6 was reported [55].…”

Section: Introductionmentioning

confidence: 99%

Composite-alumina-carbon molecular sieve membranes prepared from novolac resin and boehmite. Part II: Effect of the carbonization temperature on the gas permeation properties

Tanco

Tanaka

Mendes

2015

International Journal of Hydrogen Energy

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The influence of carbonization temperature on the permeation properties and aging of thin (4 m) supported carbon molecular sieve membranes (c-CMSM), prepared from in house synthesized novolac phenolic resin loaded with boehmite nanoparticles, were studied. Just after membrane carbonization (fresh membrane), high permeance to N2 and O2 and low O2/ N2 permselectivities were observed; the highest permeations were observed for carbonization end temperatures between 500 o C and 700 o C. After leaving the c-CMSM 1 day in the air, a large decrease in the permeation and considerable increase in the permselectivity were observed due to the reduction of the pore size by oxygen chemisorption and water physical adsorption; the permeability to H2 and H2/N2 ideal permselectivity for a mem-brane carbonized at 550 o C are close to palladium membranes for low temperature (<100 o C). The effect of the permeation characteristics of the membranes carbonized at various temperatures and the removal of water adsorbed in the pores by heat treatment were studied.

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“…The c-CMSM exhibited ideal O2/N2 and C3H6/C3H8 permselectivities of 5 and 15, respectively. The effect of Ag was also evaluated and it was observed that the load of Ag enhanced the carbon membrane performance especially for C3H6/C3H8 separation, where the C3H6/C3H8 permselectivity increased from a maximum of 15 to 38 [17,18]; however, since resol resins contain reactive methylol groups it has been realized that the permeation characteristics depends on the batch of the resin used and in the time elapsed since the resin was fabricated. The preparation of CMSM on a-alumina supports by carbonization at 500 o C and 550 o C of a resorcinolformaldehyde resin loaded with boehmite has been studied [30], the authors conclude that the membrane carbonized at 550 o C has more ultramicropores and a narrower pore size distribution and that the permselectivity after activation surpasses the Robeson upper bound for O2/N2 > 11.5.…”

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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Carbon–Al2O3–Ag composite molecular sieve membranes for gas separation

Cited by 42 publications

References 38 publications

Vacuum-assisted tailoring of pore structures of phenolic resin derived carbon membranes

Vacuum-assisted tailoring of pore structures of phenolic resin derived carbon membranes

Composite-alumina-carbon molecular sieve membranes prepared from novolac resin and boehmite. Part II: Effect of the carbonization temperature on the gas permeation properties

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

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