Solvent-mediated hydrogenolysis in coal liquefaction: Quarterly report No. 4 for the period September 16, 1985 to July 15, 1986. [Modeling of bond cleavage of dinaphthylmethane in anthracene/dihydroanthracene and phenanthrene/dihydrophenanthrene]
The objective of the present study is to explore the relevance of solvent-mediated hydrogenolysis to coal liquefaction. To this end we have investigated the cleavage rates of suitable model compounds in a variety of solvent systems with and without added coals, and assessed the relative importance of hydrogenolysis via free H-atoms and via radical hydrogen-transfer (RHT). We have been able to differentiate between hydrogenolysis via free H-atoms from that via RHT by examining the selectivity of cleavage of 1,2'-dinaphthylmethane. To further aid our understanding of the competition in cleavage of strong bonds by various modes of H-transfer, we have also conducted some mechanistic modeling studies. Finally, we are also trying to understand the impact of mass transport limitations that are likely to be important in actual coal liquefactions because of the heterogeneous nature of coal. Our approach is to bond model structures onto silica gel and study their cleavage in aromatic solvents in the presence of coal. In these experiments, the model structures, whose cleavage can be precisely monitored, cannot directly migrate to sites in coal where hydrogen becomes available, but must rely on the shuttling ability of the aromatic solvent. In this report we discuss our results of modeling cleavage of strong bonds in aromatic/hydroaromatic mixtures. During this reporting period we have optimized parameters for the RHT reactions, extended the model to the phenanthrene system, and rationalized some of the observed trends. The report also includes a brief description of our attempts to bond organic structures to silica. These materials will be used in liquefaction experiments to test the shuttling ability of different solvents. 12 refs., 3 figs., 1 tab.
- Research Organization:
- SRI International, Menlo Park, CA (USA)
- DOE Contract Number:
- FG22-84PC70810
- OSTI ID:
- 6761274
- Report Number(s):
- DOE/PC/70810-4; ON: DE87007116
- Resource Relation:
- Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
Similar Records
Factors controlling hydrogenolysis in coal liquefaction: Quarterly report No. 1 for the period July 16, 1986 to September 30, 1986
Factors controlling hydrogenolysis in coal liquefaction: Quarterly report No. 4 for the period April 1, 1987 to June 30, 1987. [1,2'-dinaphthylmethane]
Related Subjects
COAL LIQUEFACTION
ORGANIC SOLVENTS
MATHEMATICAL MODELS
HYDROGEN TRANSFER
RADICALS
ANTHRACENE
CHEMICAL BONDS
PHENANTHRENE
RESEARCH PROGRAMS
SILICA
SILICA GEL
STRUCTURAL MODELS
ADSORBENTS
AROMATICS
CHALCOGENIDES
CONDENSED AROMATICS
HYDROCARBONS
LIQUEFACTION
MINERALS
ORGANIC COMPOUNDS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
SILICON COMPOUNDS
SILICON OXIDES
SOLVENTS
THERMOCHEMICAL PROCESSES
010405* - Coal
Lignite
& Peat- Hydrogenation & Liquefaction