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Title: Molecular accessibility in oxidized and dried coals. Quarterly report, [January--March 1994]

Abstract

The objective of this research project is to determine the molecular and structural changes that occur in swelled coal as a result of oxidation and moisture loss both in the presence and absence of light using our newly developed EPR spin probe method. Looking at the over-all picture of the because of the increased cross-linking and lack of decrease in retention would be observed because of the increased cross-linking and lack of structural accessibility of the spin probes. This decrease would be observed in coals swelled in both toluene and pyridine since neither solvent is known to disrupt covalent cross-linking in coal. As the concentration of free radicals in the coal is decreased, this process would become less significant, and the production of hydroperoxides would become more important. As the oxidation process continue, production of hydroxides would cause both polar spin probes to be more strongly retained. As the hydroxyls were oxidized further to ketones, the retention of spin probe VI would become stronger than spin probe VII. However, as the ketones and hydroxyls are further oxidized to carboxylic groups, this trend would be reversed and spin probe VII. would be retained more strongly than spin probe VI. Of course,more » since the reaction products can form cross-links with other sections of the coal, this process would much more convoluted. A more complete picture of this process and its application to each individual spin probe is currently being prepared. It is apparent that the EPR spin probe method is very sensitive to the oxidation process in coal.« less

Authors:
Publication Date:
Research Org.:
Alabama Univ., University, AL (United States). Dept. of Chemistry
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
10148765
Report Number(s):
DOE/PC/93202-2
ON: DE94011119; BR: AA1525050
DOE Contract Number:  
FG22-93PC93202
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: Mar 1994
Country of Publication:
United States
Language:
English
Subject:
01 COAL, LIGNITE, AND PEAT; 47 OTHER INSTRUMENTATION; COAL; OXIDATION; ELECTRON SPIN RESONANCE; SWELLING; WEATHERING; CROSS-LINKING; RADICALS; PROGRESS REPORT; 010600; 440800; PROPERTIES AND COMPOSITION; MISCELLANEOUS INSTRUMENTATION

Citation Formats

Kispert, L.D. Molecular accessibility in oxidized and dried coals. Quarterly report, [January--March 1994]. United States: N. p., 1994. Web. doi:10.2172/10148765.
Kispert, L.D. Molecular accessibility in oxidized and dried coals. Quarterly report, [January--March 1994]. United States. doi:10.2172/10148765.
Kispert, L.D. Tue . "Molecular accessibility in oxidized and dried coals. Quarterly report, [January--March 1994]". United States. doi:10.2172/10148765. https://www.osti.gov/servlets/purl/10148765.
@article{osti_10148765,
title = {Molecular accessibility in oxidized and dried coals. Quarterly report, [January--March 1994]},
author = {Kispert, L.D.},
abstractNote = {The objective of this research project is to determine the molecular and structural changes that occur in swelled coal as a result of oxidation and moisture loss both in the presence and absence of light using our newly developed EPR spin probe method. Looking at the over-all picture of the because of the increased cross-linking and lack of decrease in retention would be observed because of the increased cross-linking and lack of structural accessibility of the spin probes. This decrease would be observed in coals swelled in both toluene and pyridine since neither solvent is known to disrupt covalent cross-linking in coal. As the concentration of free radicals in the coal is decreased, this process would become less significant, and the production of hydroperoxides would become more important. As the oxidation process continue, production of hydroxides would cause both polar spin probes to be more strongly retained. As the hydroxyls were oxidized further to ketones, the retention of spin probe VI would become stronger than spin probe VII. However, as the ketones and hydroxyls are further oxidized to carboxylic groups, this trend would be reversed and spin probe VII. would be retained more strongly than spin probe VI. Of course, since the reaction products can form cross-links with other sections of the coal, this process would much more convoluted. A more complete picture of this process and its application to each individual spin probe is currently being prepared. It is apparent that the EPR spin probe method is very sensitive to the oxidation process in coal.},
doi = {10.2172/10148765},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1994},
month = {3}
}