High temperature reactions of bibenzyl with elemental sulfur and hydrogen sulfide in the presence and absence of hydrogen and carbon monoxide
High temperature reactions were done with bibenzyl and related compounds to study C-C bond cleavage under coal liquefaction conditions. Reactions were run in 12-ml stainless steel, 3.7-ml glass and 8.0-ml aluminum autoclaves. The range of temperatures studied was 250-515/sup 0/C and that of pressure was 0-1800 psi (initial). Mechanisms for the cleavage of the aromatic-aliphatic C-C bonds (..cap alpha..-cleavage) and the aliphatic-aliphatic C-C bond (..beta..-cleavage) have been postulated. The two sets of conditions studied were: (1) those which included some form of sulfur, and those which excluded sulfur. With H/sub 2/S present, the ..beta..-cleavage to toluene was extensively promoted. The rate of this reaction was dependent on the parameters of temperature, time, H/sub 2/D concentration, and reaction surface. This ..beta..-cleavage is postulated to occur by the decomposition of the ..cap alpha..-sulfenyl bibenzyl radical. Thermal decomposition of the ..cap alpha..-sulfenyl bibenzyl radical by a known ..beta..-scission reaction yields thiobenzaldehyde and a benzyl radical which are reduced to toluene or polymerized to high molecular weight products. With molecular hydrogen present, the ..cap alpha..-cleavage to benzene and ethylbenzene is promoted. The presence of H/sub 2/S in the bibenzyl-H/sub 2/ reaction was shown to decrease the yield of ..cap alpha..-products while enhancing the conversion to 1,1-diphenylethane. The rate of ..cap alpha..-cleavage was low under essentially non-reducing conditions in this study; i.e., argon, CO-H/sub 2/O, CO-H/sub 2/O-H/sub 2/S. In this study, the mixture of carbon monoxide and water with and without hydrogen sulfide was found to be essentially non-reducing.
- Research Organization:
- North Dakota Univ., Grand Forks (USA)
- OSTI ID:
- 7150328
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BIBENZYL
CHEMICAL REACTIONS
COAL LIQUEFACTION
CHEMICAL REACTION KINETICS
HYDROGEN SULFIDES
SULFUR
AROMATICS
BENZENE
CARBON MONOXIDE
CATALYTIC EFFECTS
CHEMICAL BONDS
CLEAVAGE
COAL
HYDROGEN
QUANTITY RATIO
STAINLESS STEELS
TEMPERATURE DEPENDENCE
TIME DEPENDENCE
TOLUENE
ALKYLATED AROMATICS
ALLOYS
CARBON COMPOUNDS
CARBON OXIDES
CARBONACEOUS MATERIALS
CHALCOGENIDES
CHROMIUM ALLOYS
CORROSION RESISTANT ALLOYS
CRYSTAL STRUCTURE
ELEMENTS
ENERGY SOURCES
FOSSIL FUELS
FUELS
HYDROCARBONS
HYDROGEN COMPOUNDS
IRON ALLOYS
IRON BASE ALLOYS
KINETICS
LIQUEFACTION
MATERIALS
MICROSTRUCTURE
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
REACTION KINETICS
STEELS
SULFIDES
SULFUR COMPOUNDS
THERMOCHEMICAL PROCESSES
010405* - Coal
Lignite
& Peat- Hydrogenation & Liquefaction