Thermochemical cycles for energy storage: Thermal decomposition of ZnCO sub 4 systems
- Houston Univ., TX (United States)
The overall objective of our research has been to develop thermochemical cycles that can be used for energy storage. A specific cycle involving ammonium hydrogen sulfate (NH{sub 4}HSO{sub 4}) has been proposed. Each reaction in the proposed cycle has been examined experimentally. Emphasis has been placed on the basic chemistry of these reactions. In the concluding phase of this research, reported herein, we have shown that when NH{sub 4}HSO{sub 4} is mixed with ZnO and decomposed, the resulting products can be released stepwise (H{sub 2}A{sub (g)} at {approximately}163{degrees}C, NH{sub 3(g)} at 365--418{degrees}C, and a mixture of SO{sub 2(g)} and SO{sub 3(g)} at {approximately}900{degrees}C) and separated by controlling the reaction temperature. Side reactions do not appear to be significant and the respective yields are high as would be required for the successful use of this energy storage reaction in the proposed cycle. Thermodynamic, kinetic, and other reaction parameters have been measured for the various steps of the reaction. Finally we have completed a detailed investigation of one particular reaction: the thermal decomposition of zinc sulfate (ZnSO{sub 4}). We have demonstrated that this reaction can be accelerated and the temperature required reduced by the addition of excess ZnO, V{sub 2}A{sub 5} and possibly other metal oxides.
- Research Organization:
- National Renewable Energy Lab. (NREL), Golden, CO (United States); Houston Univ., TX (United States)
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC02-83CH10093
- OSTI ID:
- 5346223
- Report Number(s):
- NREL/TP-253-4279; ON: DE91002144
- Country of Publication:
- United States
- Language:
- English
Similar Records
Chemical and process design studies of thermochemical cycles for hydrogen production. [42% efficiency; cost $13/10/sup 6/ kj]
Alternate sulfate thermochemical hydrogen cycles for use with nuclear process heat
Related Subjects
14 SOLAR ENERGY
AMMONIUM COMPOUNDS
CHEMICAL REACTION KINETICS
THERMOCHEMICAL HEAT STORAGE
ZINC SULFATES
DECOMPOSITION
ENERGY STORAGE
LITHIUM SULFATES
MIXTURES
PROGRESS REPORT
SOLUBILITY
VANADIUM OXIDES
ZINC OXIDES
ALKALI METAL COMPOUNDS
CHALCOGENIDES
CHEMICAL REACTIONS
DISPERSIONS
DOCUMENT TYPES
HEAT STORAGE
KINETICS
LITHIUM COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
REACTION KINETICS
STORAGE
SULFATES
SULFUR COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
VANADIUM COMPOUNDS
ZINC COMPOUNDS
250800* - Energy Storage- Chemical
142000 - Solar Energy- Heat Storage- (1980-)