| 1. |
- Korelskiy, Danil, et al.
(författare)
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Efficient ceramic zeolite membranes for CO2/H2 separation
- 2015
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Ingår i: Journal of Materials Chemistry A. - 2050-7488. ; 2015:3, s. 12500-12506
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Tidskriftsartikel (refereegranskat)abstract
- Membranes are considered one of the most promising technologies for CO2 separation from industrially important gas mixtures like synthesis gas or natural gas. In order for the membrane separation process to be efficient, membranes, in addition to being cost-effective, should be durable and possess high flux and sufficient selectivity. Current CO2-selective membranes are low flux polymeric membranes with limited chemical and thermal stability. In the present work, robust and high flux ceramic MFI zeolite membranes were prepared and evaluated for separation of CO2 from H2, a process of great importance to synthesis gas processing, in a broad temperature range of 235–310 K and at an industrially relevant feed pressure of 9 bar. The observed membrane separation performance in terms both selectivity and flux was superior to that previously reported for the state-of-the-art CO2-selective zeolite and polymeric membranes. Our initial cost estimate of the membrane modules showed that the present membranes were economically viable. We also showed that the ceramic zeolite membrane separation system would be much more compact than a system relying on polymeric membranes. Our findings therefore suggest that the developed high flux ceramic zeolite membranes have great potential for selective, cost-effective and sustainable removal of CO2 from synthesis gas.
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| 2. |
- Korelskiy, Danil, et al.
(författare)
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Selective blocking of grain boundary defects in high-flux zeolite membranes by cokin
- 2017
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry. - 2050-7488. ; 5:16, s. 7295-7299
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Tidskriftsartikel (refereegranskat)abstract
- Commercial application of zeolite membranes has been hindered by the challenge of preparing defect-free membranes. Herein, we report a facile method able to selectively plug grain boundary defects in high-flux MFI zeolite membranes by coking of iso-propanol at 350 °C. After modification, the permeance via defects was reduced by 70%, whereas that via zeolite pores was reduced by only 10%.
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| 3. |
- Yu, Liang, 1986-, et al.
(författare)
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A novel method for fabrication of high-flux zeolite membranes on supports with arbitrary geometry
- 2019
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry. - 2050-7488. ; 7:17, s. 10325-10330
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Tidskriftsartikel (refereegranskat)abstract
- A novel procedure for the preparation of high-flux zeolite membranes was developed. This method relies on rendering the support hydrophobic, and thereby protected from the synthesis mixture and invasion of the support pores, while the cationic polymer on the surface still allowed deposition of zeolite seeds. Both high-flux MFI and CHA zeolite films were grown on both discs and tubular supports, which illustrates the applicability of the method to arbitrary membrane geometries. Typically, MFI disc membranes showed a very high CO2permeance of 85 × 10−7 mol m−2 s−1 Pa−1 and a CO2/H2 separation selectivity of 56 at 278 K and CHA disc membranes showed a very high CO2 permeance of 79 × 10−7 mol m−2 s−1 Pa−1 and a CO2/CH4 separation selectivity of 76 at 249 K. As the method is applicable to supports with complex geometries, it is suitable for preparation of membranes for industrial applications.
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| 4. |
- Yu, Liang, et al.
(författare)
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Highly permeable CHA membranes prepared by fluoride synthesisfor efficient CO2/CH4 separation
- 2018
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry. - 2050-7488. ; 6:16, s. 6847-6853
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Tidskriftsartikel (refereegranskat)abstract
- All-silica CHA nanocrystals, much smaller (20–200 nm) than previously reported, were prepared by an improved method developed in the present work. The nanocrystals are prepared by adding milled crystals to a fluoride synthesis mixture and we observed that much smaller crystals are obtained by adding a much higher fraction of milled crystals. In the next step, CHA membranes with a thickness of ca. 1.3 μm were prepared by hydrothermal treatment of a monolayer of nanocrystals supported on porous graded alumina discs in a fluoride synthesis gel. Finally, the membranes were calcined at 480 °C. The highest measured single gas CO2 permeance was 172 × 10−7 mol m−2 s−1 Pa−1 at room temperature. The highly permeable membranes were evaluated for separation of CO2 from an equimolar mixture with CH4 at varying temperatures. The highest observed CO2 mixture permeance was 84 × 10−7 mol m−2 s−1 Pa−1 at 276 K with a separation selectivity of 47 at 9 bar feed pressure and atmospheric permeate pressure. At room temperature, the CO2 mixture permeance was also as high as 78 × 10−7 mol m−2 s−1 Pa−1 with a separation selectivity of 32. To the best of our knowledge, these CO2 permeances are by far the highest reported for CHA membranes, while the selectivity is similar to that reported previously at comparable test conditions.
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