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U.S. Department of Energy
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Chemistry of lignite liquefaction. Quarterly report, April--June 1978

Technical Report ·
DOI:https://doi.org/10.2172/6460179· OSTI ID:6460179

Solvent refined lignite (SRL), obtained by treating lignite with carbon monoxide-hydrogen-water at 1,500 to 2,500 psi at ca. 400/sup 0/C, has an average molecular weight of ca. 460 with about 89% carbon, 6% hydrogen, 3% oxygen, 1% nitrogen and 1% sulfur with no inorganic material. SRL is highly aromatic with one acid group and 0.1 base groups per average molecule. SRL is similar to solvent refined coal in C, H and S elemental analysis, acid content, nmr and uv spectra, but lower in nitrogen and base content. The average molecular weights of SRC's and SRL's are dependent upon the conversion conditions. The average molecule of SRL has 0.86 atoms of oxygen, 0.33 atoms of nitrogen and 0.14 atoms of sulfur. Half of the oxygens are ethers and the other half are phenolic. Hydrogen bonding has now been documented as one of the major forces determining benzene solubility of SRL. The solubility of an SRL sample in benzene was increased from ca. 50% to ca. 90% by either silylation or acetylation of the sample. Since silylation destroys the hydrogen bonding capability of phenols and acetylation for both phenols and carbazoles, the conclusion was reached that hydrogen bonding causes intermolecular association among the SRL molecules. The kinds of hydrogens present in the soluble portions of SRL samples in various solvents differ from the insoluble portion. However, the aromaticity does not vary much between the soluble and insoluble portions. Solvent refined lignite can be 90% converted by catalytic hydrogenation into ca. 20% light liquids, 15% light oil, 20% heavy oil and gases. The behavior of several model compounds under carbon monoxide-water conditions at 425/sup 0/C in batch autoclaves is discussed. A possible new mechanism for the reduction of organic molecules by CO, in which there is a transfer of electrons from the catalyst surface to carbon monoxide prior to reaction with the organic molecules, is also described.

Research Organization:
North Dakota Univ., Grand Forks (USA)
OSTI ID:
6460179
Report Number(s):
FE-2211-10
Country of Publication:
United States
Language:
English