Details
| Original language | English |
|---|---|
| Pages (from-to) | 258-268 |
| Number of pages | 11 |
| Journal | Microporous and Mesoporous Materials |
| Volume | 262 |
| Early online date | 5 Dec 2017 |
| Publication status | Published - 15 May 2018 |
Abstract
Zeolite 13X, a hydrophilic adsorbent, can be used for storing thermal energy. However, its crystallinity can degrade under hydrothermal stress in the aqueous atmosphere of an adsorption storage device. This would result in a loss of energy storage capacity. There is still no known method for predicting the long-term hydrothermal stability of zeolites under relevant adsorption storage conditions. A solution for this could be a kinetic model designed with experimental data to predict hydrothermal degradation. The objective of the present study was to examine the hydrothermal stability of zeolite 13X under relevant adsorption storage conditions and to analyze its degradation in respect to the influencing factors of water vapor pressure, temperature and period of treatment. The investigated zeolite 13X powder and zeolite 13X beads have been treated at temperatures between 200 and 350 °C and water vapor pressures up to 31 kPa for treatment periods of up to 312 h. We have analyzed the changes in the zeolite structure, composition and adsorption properties by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, 27Al/29Si MAS NMR spectroscopy, molybdate method and water sorption. The results show a degradation of the crystalline zeolite 13X phase into an amorphous phase under all hydrothermal conditions, although to different degrees. Under specific hydrothermal conditions a portion of the primary crystalline phase withstands further treatment. Based on chemical decomposition mechanisms, we discuss this phenomenon. The complex stability behavior of the zeolite 13X demonstrates that a prediction beyond experimental data cannot be recommended.
Keywords
- Hydrothermal stability, Stabilization, Thermal energy storage, Water adsorbent, Zeolite 13X
ASJC Scopus subject areas
- Chemistry(all)
- General Chemistry
- Materials Science(all)
- General Materials Science
- Physics and Astronomy(all)
- Condensed Matter Physics
- Engineering(all)
- Mechanics of Materials
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In: Microporous and Mesoporous Materials, Vol. 262, 15.05.2018, p. 258-268.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Insights into the hydrothermal stability of zeolite 13X
AU - Fischer, Fabian
AU - Lutz, Wolfgang
AU - Buhl, Josef Christian
AU - Laevemann, Eberhard
N1 - Publisher Copyright: © 2017 Elsevier Inc. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2018/5/15
Y1 - 2018/5/15
N2 - Zeolite 13X, a hydrophilic adsorbent, can be used for storing thermal energy. However, its crystallinity can degrade under hydrothermal stress in the aqueous atmosphere of an adsorption storage device. This would result in a loss of energy storage capacity. There is still no known method for predicting the long-term hydrothermal stability of zeolites under relevant adsorption storage conditions. A solution for this could be a kinetic model designed with experimental data to predict hydrothermal degradation. The objective of the present study was to examine the hydrothermal stability of zeolite 13X under relevant adsorption storage conditions and to analyze its degradation in respect to the influencing factors of water vapor pressure, temperature and period of treatment. The investigated zeolite 13X powder and zeolite 13X beads have been treated at temperatures between 200 and 350 °C and water vapor pressures up to 31 kPa for treatment periods of up to 312 h. We have analyzed the changes in the zeolite structure, composition and adsorption properties by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, 27Al/29Si MAS NMR spectroscopy, molybdate method and water sorption. The results show a degradation of the crystalline zeolite 13X phase into an amorphous phase under all hydrothermal conditions, although to different degrees. Under specific hydrothermal conditions a portion of the primary crystalline phase withstands further treatment. Based on chemical decomposition mechanisms, we discuss this phenomenon. The complex stability behavior of the zeolite 13X demonstrates that a prediction beyond experimental data cannot be recommended.
AB - Zeolite 13X, a hydrophilic adsorbent, can be used for storing thermal energy. However, its crystallinity can degrade under hydrothermal stress in the aqueous atmosphere of an adsorption storage device. This would result in a loss of energy storage capacity. There is still no known method for predicting the long-term hydrothermal stability of zeolites under relevant adsorption storage conditions. A solution for this could be a kinetic model designed with experimental data to predict hydrothermal degradation. The objective of the present study was to examine the hydrothermal stability of zeolite 13X under relevant adsorption storage conditions and to analyze its degradation in respect to the influencing factors of water vapor pressure, temperature and period of treatment. The investigated zeolite 13X powder and zeolite 13X beads have been treated at temperatures between 200 and 350 °C and water vapor pressures up to 31 kPa for treatment periods of up to 312 h. We have analyzed the changes in the zeolite structure, composition and adsorption properties by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, 27Al/29Si MAS NMR spectroscopy, molybdate method and water sorption. The results show a degradation of the crystalline zeolite 13X phase into an amorphous phase under all hydrothermal conditions, although to different degrees. Under specific hydrothermal conditions a portion of the primary crystalline phase withstands further treatment. Based on chemical decomposition mechanisms, we discuss this phenomenon. The complex stability behavior of the zeolite 13X demonstrates that a prediction beyond experimental data cannot be recommended.
KW - Hydrothermal stability
KW - Stabilization
KW - Thermal energy storage
KW - Water adsorbent
KW - Zeolite 13X
UR - http://www.scopus.com/inward/record.url?scp=85037356887&partnerID=8YFLogxK
U2 - 10.1016/j.micromeso.2017.11.053
DO - 10.1016/j.micromeso.2017.11.053
M3 - Article
AN - SCOPUS:85037356887
VL - 262
SP - 258
EP - 268
JO - Microporous and Mesoporous Materials
JF - Microporous and Mesoporous Materials
SN - 1387-1811
ER -