NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Vaporization thermodynamics of K2S and K2SO3The vaporization reactions, vapor pressures, and thermodynamics of potassium sulfide and potassium sulfite were studied for purposes of providing fundamental data for the seed cycle in magnetohydrodynamic electric power generation. Rate of effusion studies, supported by tube furnace experiments, X-ray powder diffraction, mass spectrometry and appropriate chemical analyses and tests, revealed that potassium sulfite disproportionates at high temperatures to form potassium sulfide and potassium sulfate. Potassium sulfide was observed to vaporize incongruently, the initial vapors beng predominantly potassium atoms, with minor species being S2 and various K-S molecules. The ratio of K/S2 in the vapor is very large initially and decreases steadily with prolonged heating. Several materials were evaluated for purposes of containing K2S/K2SO3 at temperatures or = 800 C: Pt, Mo, W, quartz, machinable glass, BN, high density graphite, pyrolytic coated graphite, and alumina. Of these, only alumina was observed to be chemically inert to both K2S but reacted with K2SO3. The other materials were not suitable for either substance. Thermodynamic calculations based on measured vapor pressures and approximate free energy functions are described. Results from isothermal total mass loss experiments and from thermogravimetric experiments are also included.
Document ID
19830011541
Acquisition Source
Legacy CDMS
Document Type
Contractor Report (CR)
Authors
Bennet, J. E.
(Arkansas State Univ. State University, AR, United States)
Date Acquired
September 4, 2013
Publication Date
June 1, 1982
Subject Category
Chemistry And Materials (General)
Report/Patent Number
NAS 1.26:168080
NASA-CR-168080
DOE/NASA/3249-1
Accession Number
83N19812
Funding Number(s)
PROJECT: RTOP 778-11-05
CONTRACT_GRANT: NSG-3249
CONTRACT_GRANT: DE-AI01-77ET-10769
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
No Preview Available