Inorganic compounds for passive solar energy storage. Solid-state dehydration materials and high specific heat materials. Progress report
Two classes of hydrated inorganic salts have been studied to assess their potential as materials for passive solar energy storage. The materials are part of the quaternary system CaO-Al/sub 2/O/sub 3/-SO/sub 3/-H/sub 2/O and related chemical systems, and the two classes are typified by ettringite, a trisubstituted salt, and Friedel's salt, a monosubstituted salt. The trisubstituted salts were studied for their possible application in latent heat storage, utilizing a low-temperature dehydration reaction, and both classes were studies for their application in sensible heat storage. In order to assess their potential for energy storage, the salts have been synthesized, characterized by several analytical techniques, and thermal properties measured. The dehydration data of that the trisubstituted salts vary somewhat with chemical composition, with the temperature of the onset of dehydration ranging from 6/sup 0/C to 33/sup 0/C, and enthalpy changes on dehydration ranging from 60 to 200 cal/g. Heat capacity is less variable with composition; values for the trisubstituted phases are 30 cal/g//sup 0/C and for the monosubstituted phases between 0.23 and 0.28 cal/g//sup 0/C. Preliminary experiments indicate that the dehydration is reversible, and suggest that the materials might have additional potential as solar desiccant materials. These thermal data demonstrate the trisubstituted salts have potential as latent heat storage materials, and that both classes of salts have potential as sensible heat storage materials.
- Research Organization:
- National Bureau of Standards, Washington, DC (USA)
- DOE Contract Number:
- AI01-76PR06010
- OSTI ID:
- 5836156
- Report Number(s):
- NBSIR-86-3325; ON: DE86010214
- Resource Relation:
- Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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