Weathering effects on structure and reactivity of US coals. Second quarterly report

Technical Report · Tue Jan 01 04:00:00 EST 1985

OSTI ID:5758460

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

Conclusions/highlights of the second quarter are: (1) pyrolysis mass spectra, as well as classical coal characteristics, reflect rank related differences between the three Western coals studied. Differences between the Anderson lignite and the Adaville subbituminous coal are much smaller than between the latter and the high volatile A bituminous (hvAb) Hiawatha coal; (2) coal weathering is accompanied by complex weight changes. Using control runs under N/sub 2/ the effect of moisture loss can be distinguished from that of weight gain due to the oxidation. However, measuring weight gain alone is not satisfactory for monitoring the reactivity of coals towards oxygen because of the concurrent loss of compounds (e.g., CO, CO/sub 2/ and H/sub 2/O) during weathering; (3) the reactivity of coals under oxidative conditions is indicated by the pronounced loss of calorific value especially in the two lower rank coals (Anderson and Adaville No. 6). In contrast, the volatile matter/fixed carbon ratio is most strongly decreased in the weathered hvAb Hiawatha coal; (4) discriminant analysis of pyrolysis mass spectra reveals marked differences in peak series showing decreased intensities in the pyrolyzates of weathered coals of different rank. Lower rank Anderson lignite and Adaville subbituminous coal show strongly reduced dihydroxybenzene and phenol series whereas hvAb Hiawatha coal shows a pronounced loss of alkylnaphthalenes; (5) time resolved desorption/pyrolysis curves of CH/sub 3/OH/sup +/ . (m/z 32) indicate differences in polarity of the three fresh coals as well as increased polarity upon weathering in the originally less polar Hiawatha coal. The increased abundance of polar groups in the weatehred coals is also shown by the increased yield of polar compounds at lower temperatures. 9 refs., 7 figs., 5 tabs.

• Research Organization: Utah Univ., Salt Lake City (USA). Biomaterials Profiling Center
• DOE Contract Number: FG22-84PC70798
• OSTI ID: 5758460
• Report Number(s): DOE/PC/70798-T2; ON: DE85012828
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010600* -- Coal
Lignite
& Peat-- Properties & Composition
AIR
BITUMINOUS COAL
BLACK COAL
BROWN COAL
CALORIFIC VALUE
CARBONACEOUS MATERIALS
CHEMICAL COMPOSITION
CHEMICAL REACTIONS
COAL
COMBUSTION PROPERTIES
COMPARATIVE EVALUATIONS
DATA
DECOMPOSITION
ELEMENTS
ENERGY SOURCES
EXPERIMENTAL DATA
FLUIDS
FOSSIL FUELS
FUELS
GASES
INFORMATION
LIGNITE
MASS SPECTRA
MATERIALS
NITROGEN
NONMETALS
NUMERICAL DATA
PYROLYSIS
RESEARCH PROGRAMS
SPECTRA
STRUCTURAL CHEMICAL ANALYSIS
SUBBITUMINOUS COAL
THERMOCHEMICAL PROCESSES
WEATHERING
WEIGHT