Acid-base model for thermochemical water splitting: results of experimental tests on manganese-based thermochemical cycles

Conference · Tue Jan 01 00:00:00 EST 1980 · Proc. Annu. Meet. - Am. Sect. Int. Sol. Energy Soc.; (United States)

OSTI ID:6534141

Robinson, P R ^[1]; Kilyk, J Jr

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1. Oak Ridge National Lab., TN

A previously described acid-base model for thermochemical water splitting cycles is applied to cycles based upon reactions of manganese oxides. Experiments confirmed that at least 12 acids - HCl, H/sub 2/SO/sub 4/, H/sub 3/PO/sub 4/, MoO/sub 3/, NaPO/sub 3/, Na/sub 4/P/sub 2/O/sub 7/, SiO/sub 2/, Cr/sub 2/O/sub 3/, TiO/sub 2/, Al/sub 2/O/sub 3/, SnO/sub 2/, and Fe/sub 2/0/sub 3/ - drive the thermal decomposition of NaMnO/sub 2/ at temperatures below 1400 K. Only rather strong bases - NaOH, LiOH, BaO, Li/sub 2/CO/sub 3/, Na/sub 2/CO/sub 3/, NaCO/sub 3/ - can drive the steam oxidation of Mn(II) below 1300 K. In accord with the model, the acids HCl, H/sub 2/SO/sub 4/, H/sub 3/PO/sub 4/, and MoO/sub 3/ are too strong to be used in Mn(III)/(II) cycles, because their Na, Li, and Ba salts are too stable. Cycles were demonstrated with the other 8 acids and either NaOH or Na/sub 2/CO/sub 3/. Because such cycles evolve O/sub 2/(g) in the presence of air, solar furnaces are appropriate sources of thermal energy for them.

• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 6534141
• Report Number(s): CONF-800604-P2
• Journal Information: Proc. Annu. Meet. - Am. Sect. Int. Sol. Energy Soc.; (United States), Vol. 3.1; Conference: American section of the International Solar Energy Society conference, Phoenix, AZ, USA, 2 Jun 1980
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
08 HYDROGEN
HYDROGEN PRODUCTION
THERMOCHEMICAL PROCESSES
SOLAR ENERGY CONVERSION
BENCH-SCALE EXPERIMENTS
CHEMICAL REACTIONS
INORGANIC ACIDS
MANGANESE OXIDES
PERFORMANCE
SOLAR FURNACES
WATER
CHALCOGENIDES
CONVERSION
ENERGY CONVERSION
EQUIPMENT
FURNACES
HYDROGEN COMPOUNDS
MANGANESE COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
SOLAR EQUIPMENT
TRANSITION ELEMENT COMPOUNDS
140505* - Solar Energy Conversion- Photochemical
Photobiological
& Thermochemical Conversion- (1980-)
080102 - Hydrogen- Production- Thermochemical Processes