Weathering effects of structure and reactivity of US coals. First quarterly report

Technical Report · Sun Jan 01 04:00:00 EST 1984

OSTI ID:5745583

Meuzelaar, H L.C.; Hill, G R

Fresh and weathered HVAB Hiawatha seam coal samples from the Wilberg Mine in Energy County (Utah) were analyzed by time-resolved pyrolysis mass spectrometry (Py-MS). Weathering was carried out at 100/sup 0/C for 212 hours in air. The following observations were made. (1) Time-resolved Py-MS is suitable for distinguishing the following stages of degradation during fast heating (100/sup 0/C/s): moisture and solvent loss; ''mobile phase'' evaporation and degradation as well as ''side group degradation''; and pyrolysis of the ''network'' phase (char formation). (2) Time profile curves reveal differences between fresh and weathered coals. The following structural effects of weathering are observed on HVAB Hiawatha seam coal: increased methanol retention and higher yield of small polar pyrolysis products indicate increased polarity in the weathered coal, e.g., due to aromatic and aliphatic carboxylic groups formed by oxidation; the contribution of ''mobile phase'' components (e.g., alkylnaphthalenes) is decreased in the weathered coal. (3) Time-resolved recording of the total ion current in the mass spectrometer show significant differences between fresh and weathered coals. By using different electron energies the response factors for different components and, thus, the shape of the time profiles can be changed. This is a relatively simple technique requiring only a pyrolysis inlet, a small vacuum system and an ionization gauge (or similar device) while providing a sensitive tool for monitoring weathering processes in coals. 7 refs., 9 figs.

• Research Organization: Utah Univ., Salt Lake City (USA). Biomaterials Profiling Center
• DOE Contract Number: FG22-84PC70798
• OSTI ID: 5745583
• Report Number(s): DOE/PC/70798-T1; ON: DE85009126
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010600* -- Coal
Lignite
& Peat-- Properties & Composition
AIR
CARBONACEOUS MATERIALS
CHEMICAL REACTIONS
COAL
COMPARATIVE EVALUATIONS
DATA
DECOMPOSITION
ENERGY SOURCES
EXPERIMENTAL DATA
FLUIDS
FOSSIL FUELS
FUELS
GASES
INFORMATION
MASS SPECTRA
MASS SPECTROSCOPY
MATERIALS
MEDIUM TEMPERATURE
NUMERICAL DATA
PYROLYSIS
SPECTRA
SPECTROSCOPY
STRUCTURAL CHEMICAL ANALYSIS
THERMOCHEMICAL PROCESSES
WEATHERING