Investigation of dimethyl sulfoxide as a solvent in structural studies of coal and coal liquids.
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1984.
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| Subjects: | |
| Online Access: | Link to OAKTrust Copy Link to ProQuest Copy |
| Abstract: | A series of coals of increasing rank were extracted with dimethyl sulfoxide (DMSO) at room temperature. DMSO was found to yield high solubility for low rank coals. A detailed investigation of a Texas lignite, its DMSO soluble and insoluble fraction was carried out using various physico-chemical techniques such as Fourier transform infrared (FTIR) spectrometry, ('1)H nuclear magnetic resonance spectrometry (('1)HNMR) and ('13)C cross polarization/magic angle spin NMR spectrometry (('13)C CP/MAS NMR). The lignite and its DMSO soluble and insoluble fractions were further characterized by acidic functional group determination, elemental analysis and pertrifluoroacetic acid oxidation for the determination of aliphatic chain length. Concurrent studies of humic acids extracted from the same lignite were carried out for comparative purposes. The same physico-chemical and chemical techniques were used. DMSO extract of the lignite was found to be representative of the bulk lignite as well as the insoluble residue. The humic acids fraction was found to be rich in acidic functional groups and aromaticity as expected, but the sulfur content was also unusually high. This study shows that DMSO does not extract only humic acids, but, as shown by the studies undertaken, a solute which is very similar to that of the integral lignite. Ruthenium tetroxide oxidation of coals was initiated. The reagent was found to have great potential in the study of oxygen functionalities in coals. ('252)Cf plasma desorption mass spectrometry (PDMS) was used for the study of DMO extracts of coals and coal liquids and asphaltenes. The technique may find used in the study of the heavier components in well-defined and well separated extracts. DMSO was also investigated as a solvent for the study of coal liquids derived from lignites and sub-bituminous coals. Techniques such as gel permeation chromatography (GPC), gas chromatography, mass spectrometry (GC-MS) and FTIR were used to characterize the DMSO soluble and insoluble portions. DMSO has been found to be a good solvent for the separation of phenols and aromatics from coal liquids. This solvent has been found to extract a large number of polynuclear aromatic hydrocarbons which are known to be health hazards. The DMSO insolubles have been found to be rich in alkanes. This fraction has also been found to be enriched in biomarkers. A hypothetical structure has been proposed for the Texas lignite which was the subject of this study. |
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| Item Description: | Typescript (photocopy). Vita. "Major subject: Chemistry." |
| Physical Description: | xviii, 193 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references (leaves 183-192). |