Molten carbonates: microwave studies of the vapor state. Final report

Technical Report · Thu Aug 01 04:00:00 EDT 1985

OSTI ID:6471462

Gillies, C W

A high temperature microwave spectrometer was developed for the analysis of the vapor above alkali carbonates in fuel cell environments. The absorption cell utilizes nickel foil and a novel support system for the Stark septum. Both Stark modulation and radiofrequency-microwave double resonance (RFMDR) were employed for the observation of the J = 1..-->..2 transitions of potassium hydroxide in several vibrational states. This is the first application of RFMDR techniques at high temperature. The analysis of the hyperfine structure due to nuclear quadrupole splitting of the J=1..-->..2 transitions yielded quadrupole data for the ground state and the first excitations of the K-0 stretch and the degenerate bonding modes. For the ground state the unsplit frequency ..nu../sub 0/=32,834.33(5)MHz and eQq = 7.19(8)MHz. The unsplit frequencies for all states observed are consistent with rotational and distortion constants obtained from higher J transitions. Experiments with the 62 to 38 mole percent lithium-potassium carbonate eutectic in gas atmospheres which maximize the potassium hydroxide vapor concentration have failed to identify the J = 1..-->..2 transition of monomeric potassium hydroxide. Sensitivity estimates of the high temperature microwave spectrometer indicate that the potassium hydroxide concentrations fall below the detection limit in typical fuel cell gas atmospheres. 46 refs., 19 figs., 17 tabs.

• Research Organization: Rensselaer Polytechnic Inst., Troy, NY (USA). Dept. of Chemistry
• DOE Contract Number: AC02-81ER10909
• OSTI ID: 6471462
• Report Number(s): DOE/ER/10909-1; ON: DE86004504
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
300505* -- Fuel Cells-- Electrochemistry
Mass Transfer & Thermodynamics
ALKALI METAL COMPOUNDS
CARBON COMPOUNDS
CARBONATES
DIRECT ENERGY CONVERTERS
ELECTROCHEMICAL CELLS
ELECTROLYTES
ELECTROMAGNETIC RADIATION
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EVAPORATION
EXCITED STATES
FLUIDS
FUEL CELLS
GASES
HIGH-TEMPERATURE FUEL CELLS
HYDROGEN COMPOUNDS
HYDROXIDES
HYPERFINE STRUCTURE
MICROWAVE RADIATION
MICROWAVE SPECTRA
MOLTEN CARBONATE FUEL CELLS
MOLTEN SALTS
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
POTASSIUM COMPOUNDS
POTASSIUM HYDROXIDES
RADIATIONS
ROTATIONAL STATES
SALTS
SPECTRA
THERMODYNAMIC PROPERTIES
VAPOR PRESSURE
VAPORS
VIBRATIONAL STATES