Actions for The dual role of oxygen functions in coal pretreatment and liquefaction [electronic resource] : Crosslinking and cleavage reactions. Fifth quarterly report, April 1, 1992--June 30, 1992

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The dual role of oxygen functions in coal pretreatment and liquefaction [electronic resource] : Crosslinking and cleavage reactions. Fifth quarterly report, April 1, 1992--June 30, 1992

Published
Washington, D.C. : United States. Dept. of Energy, 1992.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
Physical Description
28 pages : digital, PDF file
Additional Creators
United States. Department of Energy and United States. Department of Energy. Office of Scientific and Technical Information
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Summary
Preparation of ion-exchanged (including barium, calcium and potassium) demineralized Zap and Wyodak has been completed. Both vacuum dried and moist samples were prepared, using procedures described previously. The modified samples were subjected to functional group analysis as KBr pellets with FT-IR, and programmed pyrolysis analysis with TG-FTIR. Liquefaction experiments of these samples were also performed and products were analyzed. The data show that both the pyrolytic tar and liquefaction yields decrease with the extent of ion-exchange, i.e., in the order of (demineralized) > (ion-exchanged at pH 8) > (ion-exchanged at pH 12.5). For the pyrolysis of vacuum dried samples, the tar yield was higher for the potassium-exchanged coals than the calcium and barium-exchanged samples, suggesting that bivalent cations tighten the coal structure by cross-linking coal fragments and make it more difficult for tar molecules to escape. The liquefaction results show that the potassium-exchanged samples have higher liquefaction yields (especially asphaltenes) than for the barium- and calcium-exchanged samples. This can probably be attributed to the same reason for the high pyrolytic tar yield, i.e., that bivalent cations can serve as a cross-linking agents to tighten the coal structure. Remoisturization of vacuum dried Zap and Wyodak was done in the attempt to understand if moisture uptake for low rank coals is a reversible process and to see if moisture influences the role of the cations. Preliminary results show that the moisture content can reach that of the raw samples by remoisturization for Zap, but not for Wyodak. Furthermore, the chemical structure of the coal samples seems to have been changed by remoisturization, since different CO₂ evolution behaviors were observed.
Report Numbers
E 1.99:doe/pc/91026--t5
doe/pc/91026--t5
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Other Subject(s)
Note
Published through SciTech Connect.
12/01/1992.
"doe/pc/91026--t5"
"DE93004931"
Solomon, P.R.; Teng, H.; Serio, M.A.; Kroo, E.; Charpenay, S.
Advanced Fuel Research, Inc., East Hartford, CT (United States)
Type of Report and Period Covered Note
Quarterly; 04/01/1992 - 06/30/1992
Funding Information
AC22-91PC91026
View MARC record | catkey: 13839382