Catalysis mechanism of coal liquefaction by H/sub 2/S. Final report, September 21, 1982-March 31, 1986
More detailed data has been generated during the course of this contract to substantiate the modes in which hydrogen sulfide promotes liquefaction: (1) by hydrocracking; (2) hydrogen atom donation; (3) form aromatic sulfur bonds by pi-orbital attack; (4) catalyze the shift reaction; and (5) interaction with coal via an elemental sulfur intermediate. H/sub 2/S is now demonstrated to be catalytic with its quantitative recovery at the end of each reaction provided the reactor surface is presulfided. Low concentrations of H/sub 2/S of about 100 psi are optimum for coal conversion in an organic media. The metal reactor wall has been demonstrated to participate when H/sub 2/S is present. Hydrogen sulfide promotes the liquefaction of three ranks of coals: lignites, subbituminous and bituminous coals both in the absence and presence of a good hydrogen donor solvent. Therefore, it does more than merely act as a good hydrogen donor. The iron of the metal reactors was continually interfering with the data. Consequently, it was necessary to develop this chemistry. The H/sub 2/S proved to be converting the surface iron into pyrrhotite. Through collaboration with Montano, it was next possible to postulate and obtain experimental evidence for the chemical mechanism of how H/sub 2/S and iron act synergistically to promote liquefaction. This detailed surface chemistry has now been published. Hydrogen sulfide promotes the hydrocracking of all model compounds. The principal mechanism given for this is via SH aromatic pi-orbital attack followed by decoupling of the substituent. Bibenzyl follows an unusual mechanism. 29 refs., 17 tabs.
- Research Organization:
- North Dakota Univ., Grand Forks (USA). Dept. of Chemistry
- DOE Contract Number:
- FG22-82PC50814
- OSTI ID:
- 5916624
- Report Number(s):
- DOE/PC/50814-T10; ON: DE86010667
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
010405* -- Coal
Lignite
& Peat-- Hydrogenation & Liquefaction
BITUMINOUS COAL
BLACK COAL
BROWN COAL
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CARBONACEOUS MATERIALS
CATALYSIS
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHEMICAL REACTORS
COAL
COAL LIQUEFACTION
CRACKING
DECOMPOSITION
ELEMENTS
ENERGY SOURCES
FOSSIL FUELS
FUELS
HYDROCRACKING
HYDROGEN COMPOUNDS
HYDROGEN SULFIDES
IRON
IRON COMPOUNDS
IRON SULFIDES
KINETICS
LIGNITE
LIQUEFACTION
MATERIALS
METALS
MINERALS
OXIDES
OXYGEN COMPOUNDS
PYROLYSIS
PYRRHOTITE
REACTION KINETICS
RESEARCH PROGRAMS
STRUCTURAL MODELS
SUBBITUMINOUS COAL
SULFIDE MINERALS
SULFIDES
SULFUR COMPOUNDS
SYNERGISM
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS