Improved coal conversion in CO/water systems. Quarterly report No. 6, December 4, 1985-March 3, 1986
This report describes the results of initial studies designed to test the suggestion that the effectiveness of CO/water/base systems in coal conversion can be attributed to the susceptibility of the keto-forms of phenolic coal structures to reaction with hydride- and electron-transfer reagents. The dealkylation, deoxygenation, and coupling or retrograde reactions of p-benzylphenol, 9-phenanthrol, o.o'-biphenol, 2-methyl-l-naphthol, and veratrole (1,2-dimethoxybenzene) have been studied as representative of classes important in coal conversion. Experiments were conducted in fused silica ampoules and stainless steel microautoclaves using at least two donor solvents (typically tetralin and tetralin/THQ) and in CO/H/sub 2/O/KOH systems. Comparison of the conversion rates in the organic and aqueous systems led to the conclusions summarized below: Both dealkylation and deoxygenations can be faster in CO/H/sub 2/O/KOH systems. Dealkylation rate appears to correlate with the amount of base, possibly due to nucleophilic displacement. Deoxygenation is not accelerated when dealkylation is a viable alternative. H/sub 2/O/Base can substantially accelerate coupling reactions. This tendency is moderated by CO. Alkylated polyoxygenated structures undergo rapid Ar-O cleavage. The results of our study suggest that the increased pyrolysis yields reported on methylation of low-rank coals are due not only to protection of hydroxyls from coupling reactions but are also due to enhanced cleavage of the strong Ar-O bonds. These results suggest that the facile dissolution of subbituminous coals in alcoholic KOH media could well be due to reactions of partially alkylated polyphenolic structures rather than to hydrolysis of esters, as has been previously asserted. 18 refs., 3 figs., 6 tabs.
- Research Organization:
- SRI International, Menlo Park, CA (USA)
- DOE Contract Number:
- FG22-84PC70811
- OSTI ID:
- 5406479
- Report Number(s):
- DOE/PC/70811-6; ON: DE86015548
- Resource Relation:
- Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
COAL LIQUEFACTION
CHEMICAL REACTION KINETICS
RESEARCH PROGRAMS
YIELDS
CARBON MONOXIDE
CONDENSED AROMATICS
DEALKYLATION
LIGNITE
ORGANIC SOLVENTS
POTASSIUM HYDROXIDES
PYROLYSIS
QUINOLINES
REDUCTION
STRUCTURAL MODELS
SUBBITUMINOUS COAL
TETRALIN
WATER
ALKALI METAL COMPOUNDS
AROMATICS
AZAARENES
AZINES
BROWN COAL
CARBON COMPOUNDS
CARBON OXIDES
CARBONACEOUS MATERIALS
CHALCOGENIDES
CHEMICAL REACTIONS
COAL
DECOMPOSITION
ENERGY SOURCES
FOSSIL FUELS
FUELS
HETEROCYCLIC COMPOUNDS
HYDROCARBONS
HYDROGEN COMPOUNDS
HYDROXIDES
KINETICS
LIQUEFACTION
MATERIALS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
POTASSIUM COMPOUNDS
PYRIDINES
REACTION KINETICS
SOLVENTS
THERMOCHEMICAL PROCESSES
010405* - Coal
Lignite
& Peat- Hydrogenation & Liquefaction