Xuerui Wang 


Van der Maasweg 9, 2629 HZ Delft 
Room E2.140

Tel: *31 (0) 15 27 84413

X.Wang-12@tudelft.nl 


Commercially attractive zeolite membranes for gas separation 

Membrane constructed from crystalline zeolite with well-defined microporous structure is promising to achieve a unique separation principally based on molecular size exclusion, adsorption, and diffusion. Polycrystalline zeolite membranes have been demonstrated to be fascinating for solvent dehydration by pervaporation, seawater desalination by pressure related osmosis, xylene isomers separation, and gas separations in the laboratory.[1] Notably, industrial implementation of hydrophilic LTA-, FAU-, and T-type zeolite membranes have been achieved for organic solvent dehydration and bio-ethanol production. However, the commercialization of zeolite membrane for gas separation requires further reduction of fabrication cost. Polycrystalline zeolite membranes are currently fabricated by hydrothermal synthesis, wherein large amount of the chemicals (>96 %) are wasted through the formation of unwanted zeolite powders.[2][3] In this regard, the gel-free growth induced by water steam appears to be the only way forward. Since the membrane costs are further dominated by the support costs (>70 %) and not by the zeolite layer, an interesting alternative is the replacement of the expensive ceramic substrates by cheap alternatives such as metal grids or simply perforated thin metal sheets.[1] Improving the packing density of module (ratio of membrane area to module volume) is critical as well to suppress the high capital investment of zeolite membrane plant. Meanwhile, both selectivity and reproducibility are extremely challenging for the scale-up preparation of zeolite membranes. It turned out to be rather challenging to achieve single-crystal-like zeolite membranes without non-zeolitic defects. These defects with larger pore size than the ideal aperture size (e.g., 1.4 nm vs 0.42nm for commercial LTA membrane) can be compensated by the preferential water adsorption for aqueous solvent pervaporation. However, the fraction of non-zeolitic pore area should constitute less than 10 ppm for a zeolite membrane to render it separating the less polar gases through molecular sieving.[4][5] Even though record selectivities could be achieved by controlling preferential orientation of zeolite crystals and healing defects or cracks, the reproducibility is believed to be the biggest obstacles for the commercialization and industrial application of zeolite membrane for gas separation.

The aim of this project is to develop novel, robust, highly reproducible and easy to sacle-up methods for the production of commercially attractive zeolite membranes. Challenging applications of the synthesized zeolite membranes will include CO2 separation for pre-combustion CO2 capture in power plants and natural gas upgrading, and anaesthetic gas recovery during surgery.

Acknowledgements 

This research is supported by STW - New avenues for the fabrication of zeolite membranes (Project Number 13941)  

References

[1] J. Gascon, F. Kapteijn, B. Zornoza, V. Sebastián, C. Casado, J. Coronas, Practical approach to zeolitic membranes and coatings: State of the art, opportunities, barriers, and future perspectives, Chem Mater, 24 (2012) 2829-2844.

[2] T.C.T. Pham, H.S. Kim, K.B. Yoon, Growth of uniformly oriented silica MFI and BEA zeolite films on substrates, Science, 334 (2011) 1533-1538.

[3] M.Y. Jeon, D. Kim, P. Kumar, P.S. Lee, N. Rangnekar, P. Bai, M. Shete, B. Elyassi, H.S. Lee, K. Narasimharao, S.N. Basahel, S. Al-Thabaiti, W. Xu, H.J. Cho, E.O. Fetisov, R. Thyagarajan, R.F. DeJaco, W. Fan, K.A. Mkhoyan, J.I. Siepmann, M. Tsapatsis, Ultra-selective high-flux membranes from directly synthesized zeolite nanosheets, Nature, 543 (2017) 690-694.

[4] N. Kosinov, J. Gascon, F. Kapteijn, E.J.M. Hensen, Recent developments in zeolite membranes for gas separation, J Membr Sci, 499 (2016) 65-79.

[5] M. Tsapatsis, Toward high-throughput zeolite membranes, Science, 334 (2011) 767-768.