Engineering considerations for thermochemical hydrogen production. [Energy efficiency determinations]
Hydrogen production by thermochemical water-splitting has been proposed as an energy conversion process for using heat to produce a chemical fuel from an abundant material resource. The thermochemical hydrogen program at IGT, sponsored by the American Gas Association, is now in its fifth year. In this largely experimental program, we have made detailed energy efficiency determinations for about 95 theoretically possible cycles, and we have tested the reaction steps of about 65 cycles, including some proposed by other investigators. These theoretical and laboratory studies have shown that the important engineering parameters are energy efficiency, energy source, material corrosivity, hydrogen pressure capability, reaction rate, and materials availability and cost. These parameters are interrelated and contribute to the practicality of thermochemical hydrogen production. Our analytical assessments indicate that thermochemical cycles can be more efficient than advanced-technology electricity generation/electrolysis for converting heat energy into chemical energy, but only when the maximum process temperature exceeds about 700/sup 0/C. To be both efficient and operable, most thermochemical cycles will need some 800/sup 0/C heat; this implies nuclear-core exit temperatures of about 900/sup 0/C or higher.
- Research Organization:
- Institute of Gas Technology, Chicago, IL (USA)
- OSTI ID:
- 7233210
- Report Number(s):
- CONF-761044-2
- Country of Publication:
- United States
- Language:
- English
Similar Records
Reaction experiments for thermochemical water-splitting. [Classes of cycles: metal-metal oxide; metal oxide-metal hydroxide; metal oxide-metal sulfate; metal-metal halide; metal oxide-metal halide]
Advanced Electrochemical Technologies for Hydrogen Production by Alternative Thermochemical Cycles