Details
| Original language | English |
|---|---|
| Pages (from-to) | 25-37 |
| Number of pages | 13 |
| Journal | Microporous and Mesoporous Materials |
| Volume | 49 |
| Issue number | 1-3 |
| Early online date | 30 Oct 2001 |
| Publication status | E-pub ahead of print - 30 Oct 2001 |
| Externally published | Yes |
Abstract
In the last 10 years extensive work was done in the preparation and characterization of molecular sieve membranes, especially of the types MFI, LTA and FAU. There is a remarkable progress in the synthesis of MFI membranes from the pure silica crystallization system. These silicalite-1 membranes show both separation properties by molecular size exclusion and by molecular interaction because of the hydrophobic interaction of the silica surface with permeating molecules. Silicalite-1 membranes exhibit promising permeation properties for industrially interesting mixtures as n-/ iso-alkanes or the xylene isomers. However, so far these membranes are available only with areas of 1-10 cm2, and the reproducibility of the membrane preparation is unsatisfactory. The yield of high-quality membranes is in the range of 10-30% of the preparations. In this work the membrane area was enlarged by the factor of 30, and the support shape was changed from a flat disc to a tube geometry. This was achieved by the optimization of the synthesis gel composition and the synthesis conditions. Furthermore, by changing the prepared membrane type from a mono- to a polylayer and by varying the calcination conditions, the density and size of leaks could be reduced. As a result of all these measures the yield of high-quality membranes with a minimum permselectivity of H2 to SF6 of 43 (which is five times the Knudsen factor) as a quality criterium was increased to 70% of all preparations. Special attention was given to the economy of the synthesis of MFI membranes which implies to save material, energy and time.
Keywords
- Economical formation, Large area membranes, MFI membranes, Optimization of synthesis, Reproducibility
ASJC Scopus subject areas
- Chemistry(all)
- Materials Science(all)
- Physics and Astronomy(all)
- Condensed Matter Physics
- Engineering(all)
- Mechanics of Materials
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In: Microporous and Mesoporous Materials, Vol. 49, No. 1-3, 30.10.2001, p. 25-37.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Preparation of MFI membranes of enlarged area with high reproducibility
AU - Noack, M.
AU - Kölsch, P.
AU - Schäfer, R.
AU - Toussaint, P.
AU - Sieber, I.
AU - Caro, J.
PY - 2001/10/30
Y1 - 2001/10/30
N2 - In the last 10 years extensive work was done in the preparation and characterization of molecular sieve membranes, especially of the types MFI, LTA and FAU. There is a remarkable progress in the synthesis of MFI membranes from the pure silica crystallization system. These silicalite-1 membranes show both separation properties by molecular size exclusion and by molecular interaction because of the hydrophobic interaction of the silica surface with permeating molecules. Silicalite-1 membranes exhibit promising permeation properties for industrially interesting mixtures as n-/ iso-alkanes or the xylene isomers. However, so far these membranes are available only with areas of 1-10 cm2, and the reproducibility of the membrane preparation is unsatisfactory. The yield of high-quality membranes is in the range of 10-30% of the preparations. In this work the membrane area was enlarged by the factor of 30, and the support shape was changed from a flat disc to a tube geometry. This was achieved by the optimization of the synthesis gel composition and the synthesis conditions. Furthermore, by changing the prepared membrane type from a mono- to a polylayer and by varying the calcination conditions, the density and size of leaks could be reduced. As a result of all these measures the yield of high-quality membranes with a minimum permselectivity of H2 to SF6 of 43 (which is five times the Knudsen factor) as a quality criterium was increased to 70% of all preparations. Special attention was given to the economy of the synthesis of MFI membranes which implies to save material, energy and time.
AB - In the last 10 years extensive work was done in the preparation and characterization of molecular sieve membranes, especially of the types MFI, LTA and FAU. There is a remarkable progress in the synthesis of MFI membranes from the pure silica crystallization system. These silicalite-1 membranes show both separation properties by molecular size exclusion and by molecular interaction because of the hydrophobic interaction of the silica surface with permeating molecules. Silicalite-1 membranes exhibit promising permeation properties for industrially interesting mixtures as n-/ iso-alkanes or the xylene isomers. However, so far these membranes are available only with areas of 1-10 cm2, and the reproducibility of the membrane preparation is unsatisfactory. The yield of high-quality membranes is in the range of 10-30% of the preparations. In this work the membrane area was enlarged by the factor of 30, and the support shape was changed from a flat disc to a tube geometry. This was achieved by the optimization of the synthesis gel composition and the synthesis conditions. Furthermore, by changing the prepared membrane type from a mono- to a polylayer and by varying the calcination conditions, the density and size of leaks could be reduced. As a result of all these measures the yield of high-quality membranes with a minimum permselectivity of H2 to SF6 of 43 (which is five times the Knudsen factor) as a quality criterium was increased to 70% of all preparations. Special attention was given to the economy of the synthesis of MFI membranes which implies to save material, energy and time.
KW - Economical formation
KW - Large area membranes
KW - MFI membranes
KW - Optimization of synthesis
KW - Reproducibility
UR - http://www.scopus.com/inward/record.url?scp=0035498022&partnerID=8YFLogxK
U2 - 10.1016/S1387-1811(01)00396-1
DO - 10.1016/S1387-1811(01)00396-1
M3 - Article
AN - SCOPUS:0035498022
VL - 49
SP - 25
EP - 37
JO - Microporous and Mesoporous Materials
JF - Microporous and Mesoporous Materials
SN - 1387-1811
IS - 1-3
ER -