Degree Name

Master of Science (MS)

Semester of Degree Completion

1989

Thesis Director

David H. Buchanan

Abstract

The hypothesis that hydrogen-bonded ethers in coal could be cleaved by reaction with lithium iodide in pyridine to form new phenol groups was investigated for coals #2, 3, and 5 plus their alkylated derivatives from the Argonne Premium Coal Sample Program. Changes caused by alkylation and reaction with LiI were monitored by solvent extraction yeilds, solvent swelling, FT-IR and Size Exclusion Chromatography (SEC).

Solubilities of alkylated coals are rank and oxygen functionality dependent. Evidence supports the hypothesis that the solubilization mechanism is dependent on the extent of hydrogen-bonding in the coal. Elimination of hydrogen-bonds through alkylation increases toluene solubility and decreases pyridine solubility. The theory that carboxylic groups in the subbituminous coal are coordinated to divalent metal ions is supported by the observed increase in pyridine solubility upon alkylation of the subbituminous coal.

The reaction of LiI with both raw and alkylated coal caused slight increases in the -OH absorption in the FT-IR spectra. Treatment with LiI decreases toluene solubility for alkylated medium and lower rank coals. In most cases pyridine solubility decreased after LiI treatment. SEC profiles showed no change upon reaction with LiI. Data suggests that the final product does not have the proposed additional -OH .groups for each cleaved ether. It is suggested that further reaction of the cleavage products with other groups in the coal occurs.

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