Zeolite membranes have great potential in gas separation applications because of
their unique selective properties. The main challenge is in synthesizing defect-free zeolite
membranes. In this study, we synthesized silicalite-1 zeolite membranes on ceramic
supports composed of Al2O3 and TiO2 using the pore-plugging method. We investigated
the effect of the fill-level in the autoclave during the synthesis on the membrane
performance. In particular, we were interested in determining the conditions at which the
defects' contribution to the total transport is minimized. We adopted and further developed
the approach proposed by Carter (2019) to quantify the permeance contribution through
defects. Comparing the membrane performance before and after calcination, we proposed
several modifications to the original analysis of Carter (2019). Knowing the defect
transport contribution, we determined the corrected diffusivity, an intrinsic property of
zeolite crystals at a given temperature, of several adsorbed gases on silicalite-1 crystals.
The defect's contribution decreased as the autoclave fill-level increased from 94 to
98%. A further increase in the autoclave fill-level introduced more defects and caused the
autoclave lid to rupture. Despite the differences in the membranes' performance arising
from the autoclave fill-level, the corrected diffusivities of CO2, CH4, and N2 in silicalite-1
showed minimal variation from membrane to membrane. This proves the validity of the
proposed characterization method. Moreover, the reported corrected diffusivities are
comparable to the literature's values, found using other characterization methods.
However, none of the previously used methods is as simple and straightforward as the one
we further developed in this study.
| Identifer | oai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/41577 |
| Date | 17 December 2020 |
| Creators | Al-Akwaa, Shaaima |
| Contributors | Kruczek, Boguslaw, Tezel, F. Handan |
| Publisher | Université d'Ottawa / University of Ottawa |
| Source Sets | Université d’Ottawa |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf |
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