A new determination of exchangeable oxygen in coals
- Univ. of North Dakota Energy and Mineral Research Center, Grand Forks (USA)
Finseth has recently reported a new method for the determination of water in coals which utilizes isotope dilution. In this technique, a known amount of water which was enriched in {sup 18}O was added to the weighed coal sample in a tube. Carbon dioxide was also added and the tube sealed and then heated to equilibrate the added labeled water with the natural abundance water present in the sample. The tube was then opened and the carbon dioxide analyzed by mass spectrometry to determine the isotopic ratio, from which the coal moisture could be calculated. The carbon dioxide acted as a probe molecule to facilitate the mass spectrometric analysis, since its oxygens exchange completely with those of the water. The results of Finseth's moisture determinations were compared with ASTM values for a number of Argonne premium coal samples and were in all cases somewhat larger than the ASTM values. The mass spectrometers available in their laboratories are not adaptable to analysis of the CO{sub 2}, hence the authors sought an alternative for the analysis of the isotope ratio in the isotopically equilibrated water samples. The reaction of the water with several orthoesters to give the ester containing the water-derived oxygen (labeled oxygen) in the carbonyl group was investigated. The orthoester selected for the analysis was trimethyl orthobenzoate, since it gave methyl benzoate which could be conveniently analyzed in our GC/FTIR/MS system. Results are discussed.
- OSTI ID:
- 5432479
- Report Number(s):
- CONF-8806136-; CODEN: ACFPA
- Journal Information:
- Preprints of Papers, American Chemical Society, Division of Fuel Chemistry; (USA), Vol. 33:2; Conference: American Chemical Society Division of Fuel Chemistry meeting, Toronto (Canada), 5-10 Jun 1988; ISSN 0569-3772
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
COAL
CHEMICAL ANALYSIS
OXYGEN
BITUMINOUS COAL
CARBON DIOXIDE
CHEMICAL REACTIONS
ESTERS
FOURIER TRANSFORMATION
GAS CHROMATOGRAPHY
INFRARED SPECTRA
ISOTOPE RATIO
ISOTOPIC EXCHANGE
LIGNITE
MASS SPECTROSCOPY
MOISTURE
OXYGEN 18
BLACK COAL
BROWN COAL
CARBON COMPOUNDS
CARBON OXIDES
CARBONACEOUS MATERIALS
CHALCOGENIDES
CHROMATOGRAPHY
ELEMENTS
ENERGY SOURCES
EVEN-EVEN NUCLEI
FOSSIL FUELS
FUELS
INTEGRAL TRANSFORMATIONS
ISOTOPES
LIGHT NUCLEI
MATERIALS
NONMETALS
NUCLEI
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
OXYGEN ISOTOPES
SEPARATION PROCESSES
SPECTRA
SPECTROSCOPY
STABLE ISOTOPES
TRANSFORMATIONS
010600* - Coal
Lignite
& Peat- Properties & Composition