Zinc chloride-catalyzed reactions of oxygen- and sulfur-containing compounds which model structures in coal
Ether structures are believed to play a key role in linking the macromolecular units present in coal. A number of compounds which model the ether and sulfur structures found in coal were subjected to reaction in the presence of zinc chloride. Reactions were carried out in a batch autoclave at temperatures between 136/sup 0/C and 327/sup 0/C and under hydrogen or nitrogen pressure up to 16.8 MPa. Both cyclic and non-cyclic ethers reacted, provided that at least one methylene group was adjacent to the ether oxygen atom. Complete elimination of oxygen to form water was achieved with dibenzyl and cycloaliphatic ethers, but oxygen bonded directly to a phenyl or naphthyl group was converted to an unreactive phenolic hydroxyl group. As for the sulfur compounds, zinc chloride was found to promote removal of sulfur from sulfides and disulfides in which sulfur is bonded to a methylene group, but had no effect on diaryl sulfides, diaryl disulfides, or thiophenic structures. In those cases where sulfur was removed, a significant portion was found to be retained in the ZnCl/sub 2/ phase. The reaction products observed in both cases can be explained in terms of carbonium ion mechanisms similar to those used to explain Friedel-Crafts chemistry. In these mechanisms, the ZnCl/sub 2/ may be active in either a Lewis acid or a Bronsted acid form. Catalytic effects of nickel, zinc and magnesium and also the sulfides of nickel, zinc, iron and molybdenum on the reactions of dibenzyl ether and zinc chloride were also investigated. The presence of the metallic component enhanced the hydrogenolysis of dibenzyl ether, whereas the presence of ZnCl/sub 2/ reduced the activity of the NiS.
- Research Organization:
- California Univ., Berkeley (USA). Lawrence Berkeley Lab.
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 6812194
- Report Number(s):
- LBL-11026
- Resource Relation:
- Other Information: Thesis
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
01 COAL, LIGNITE, AND PEAT
AROMATICS
CHEMICAL REACTIONS
CRESOLS
ETHERS
CATALYTIC EFFECTS
IRON
MAGNESIUM
MOLYBDENUM SULFIDES
NAPHTHOLS
NICKEL
NICKEL SULFIDES
PHENOLS
SULFIDES
ZINC
ZINC CHLORIDES
ZINC SULFIDES
CHEMICAL COMPOSITION
COAL
HIGH PRESSURE
HIGH TEMPERATURE
HYDROGEN
ALKALINE EARTH METALS
CARBONACEOUS MATERIALS
CHALCOGENIDES
CHLORIDES
CHLORINE COMPOUNDS
ELEMENTS
ENERGY SOURCES
FOSSIL FUELS
FUELS
HALIDES
HALOGEN COMPOUNDS
HYDROXY COMPOUNDS
INORGANIC PHOSPHORS
MATERIALS
METALS
MOLYBDENUM COMPOUNDS
NICKEL COMPOUNDS
NONMETALS
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PHOSPHORS
SULFUR COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
ZINC COMPOUNDS
ZINC HALIDES
400301* - Organic Chemistry- Chemical & Physicochemical Properties- (-1987)
010600 - Coal
Lignite
& Peat- Properties & Composition