Development of a photochemical energy storage system. Final technical report, September 1, 1979-November 30, 1982
An attractive strategy for photochemical energy storage involves the use of endoergic photorearrangements of organic molecules. By far the most promising system of this type involves the inter-conversion of norbornadiene, NBD, and quadricyclene, Q. Although NBD is transparent in the spectral region of abundant solar radiation (> 300 nm), the photoreaction does occur at longer wavelengths in the presence of an appropriate spectral sensitizer with an overall quantum efficiency of Q production approaching 100% in optimal cases. The specific energy storage capacity, approx. 250 cal per gram (approx. 1 x 10/sup 6/ joule/kg) of Q produced, is larger than the common thermal storage materials. Long-term energy storage is realized, since Q is indefinitely stable toward reversion to NBD under ordinary conditions. Addition of an appropriate catalyst, however, causes rapid (within seconds) conversion of Q to NBD with the release of the stored energy as heat. Quantum efficient sensitizers are needed which absorb strongly in the visible wavelength region and are thermally and photochemically stable such as silica-functionalized organic photosensitizers. Furthermore, while several catalysts for the reverse reaction are known, it would be advantageous to have ones which are relatively inexpensive and ones which would offer a range of catalytic activity in order to select the optimal rate for the reconversion at ambient temperatures. Transition metal catalysts such as cobalt were tested. Finally, there are substantial benefits which arise from spatially confining the sensitizer and reversion catalyst to their appropriate sections in a functional energy storage system. Immobilization of each component onto separate heterogeneous supports offers an attractive method for accomplishing this. Our research group has been actively involved in each of these areas since 1975. Accomplishments during the three-year period covered by the present grant are reviewed in this report. (DMC)
- Research Organization:
- Georgia Univ., Athens (USA). Dept. of Chemistry
- DOE Contract Number:
- FG02-79ER10540
- OSTI ID:
- 5303985
- Report Number(s):
- DOE/ER/10540-T1; ON: DE84005242
- Resource Relation:
- Other Information: Portions are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
14 SOLAR ENERGY
COBALT
CATALYTIC EFFECTS
NORBORNADIENE
PHOTOCHEMICAL REACTIONS
PHOTOCHEMICAL ENERGY STORAGE
QUADRICYCLENE
RHODIUM
SILICA
PHOTOSENSITIVITY
CATALYSIS
PORPHYRINS
PYRIDINE
TRANSITION ELEMENTS
ALKENES
AZINES
CARBOXYLIC ACIDS
CHALCOGENIDES
CHEMICAL REACTIONS
CYCLOALKENES
ELEMENTS
ENERGY STORAGE
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYDROCARBONS
METALS
MINERALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PLATINUM METALS
PYRIDINES
SENSITIVITY
SILICON COMPOUNDS
SILICON OXIDES
STORAGE
400500* - Photochemistry
140505 - Solar Energy Conversion- Photochemical
Photobiological
& Thermochemical Conversion- (1980-)