Interrelationship of chemical characterization and rheological behaviour of coal liquefaction bottoms

✍ Scribed by Frank F. Tao; Rustom Billimoria

• Publisher: Elsevier Science
• Year: 1984
• Tongue: English
• Weight: 678 KB
• Volume: 63
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/0016-2361(84)90029-2

✦ Synopsis

In the development of the Exxon Donor Solvent (EDS) process, bituminous and subbituminous coals have been processed in a one ton-per-day coal liquefaction pilot plant using the feed coal slurried with solvent and with or without bottoms recycle. The liquefaction bottoms from both once-through and bottoms recycle operation exhibit non-Newtonian viscometric behaviour. The recycled bottoms, however, are more viscosity/shear dependent, less viscosity/temperature dependent and more thermally stable than the once-through bottoms. Chemical characterization of these bottoms reveals that alkyl and phenoxy groups are important functional groups responsible for the viscometric behaviour of bottoms. The increase of bottoms viscosity is postulated to involve the elimination/condensation of methylene units are phenolic functional groups to form the crosslinkages of large aromatic clusters.