MSc Assignment: Fabrication of defect-free high-silica CHA zeolite membranes for gas separation applications

Zeolite membranes are one of the pioneering membrane materials for the separation of gases as they are mechanically, chemically and thermally stable at extreme process conditions and have uniform and molecular-sized pore structures. Chabazite (CHA) type zeolite framework is one of the smallest pore size (0.38 nm) zeolite structures that could be used as membrane material for the separation of gases [1–3] such as N2/CH4 and CO2/CH4 in natural gas purification.

The main challenge in zeolite membranes to be implemented in large scale chemical industries is the formation of defects during the crystal growth and template removal steps. There are various methods developed such as rapid thermal processing [4], ozonication [5] and ultraviolet irradiation [6] to overcome the defect formation during template removal steps which would also be used as alternative approaches to the conventional calcination treatment.

In this project, the CHA seed crystals will be produced, attached on porous supports and growth into a continuous zeolite layer as shown in Figure 1. By the control of the synthesis parameters and optimization of the fabrication technique, the defect formation will be eliminated which eventually bring us high gas separation performances.


Figure 1: The SEM images of the CHA seed crystals (on the left) which are further deposited on a porous support and grown into a continuous zeolite membrane layer

The master student will benefit from the knowledge and expertise of the Inorganic membranes group for:

1.       Synthesis of high-silica CHA seed crystals and their growth into zeolite membranes

2.       Characterization of the synthesized materials by various techniques such as X-Ray Diffraction (XRD), X-Ray Fluorescence(XRF), thermogravimetric analysis (TGA), confocal microscopy, scanning electron microscopy (SEM), N2 adsorption/desorption

3.       Evaluation of the performance of the membranes in single gas permeation and mixed gas separation.

For more information, please contact:

Pelin Karakiliç (p.karakilic@utwente.nl), Inorganic Membranes group, Meander 236B

Louis Winnubst (a.j.a.winnubst@utwente.nl), Inorganic Membranes, Meander 348

 

[1] K. Kida, Y. Maeta, K. Yogo, Pure silica CHA-type zeolite membranes for dry and humidified CO2/CH4 mixtures separation, Sep. Purif. Technol. 197 (2018) 116–121. [2] H. Kalipcilar, T.C. Bowen, R.D. Noble, J.L. Falconer, Synthesis and Separation Performance of SSZ-13 Zeolite Membranes on Tubular Supports, Chem. Mater. 14 (2002) 3458–3464. [3] Y. Zheng, N. Hu, H. Wang, N. Bu, F. Zhang, R. Zhou, Preparation of steam-stable high-silica CHA (SSZ-13) membranes for CO2/CH4 and C2H4/C2H6 separation, J. Memb. Sci. 475 (2015) 303–310. [4] J. Choi, H.-K. Jeong, M.A. Snyder, J.A. Stoeger, R.I. Masel, M. Tsapatsis, Grain Boundary Defect Elimination in a Zeolite Membrane by Rapid Thermal Processing, Science. 325 (2009) 590–593. [5] N. Kosinov, C. Auffret, V.G.P. Sripathi, C. Gücüyener, J. Gascon, F. Kapteijn, et al., Influence of support morphology on the detemplation and permeation of ZSM-5 and SSZ-13 zeolite membranes, Microporous Mesoporous Mater. 197 (2014) 268–277. [6] S. Yang, Y.H. Kwon, D.-Y. Koh, B. Min, Y. Liu, S. Nair, Highly Selective SSZ-13 Zeolite Hollow Fiber Membranes by Ultraviolet Activation at Near-Ambient Temperature, ChemNanoMat. (2018) 2–9.