Liquefaction reaction of coal: 1. Depolymerization of coal by cleavages of ether and methylene bridges

✍ Scribed by Tadashi Yoshida; Kazuaki Tokuhashi; Yosuke Maekawa

• Publisher: Elsevier Science
• Year: 1985
• Tongue: English
• Weight: 684 KB
• Volume: 64
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/0016-2361(85)90138-3

✦ Synopsis

The roles of ether and methylene bridges in the depolymerization of coal have been reevaluated on the basis of the results of a mild liquefaction reaction (4OOC, 30 min) and the distributions of oxygen and carbon atoms obtained by cross-polarization, magic angle spinning (CP/MAS) ' %Z n.m.r. spectrometry. Coals ranging from 66.2 to 87.4 wt% C (dmmf) were used as sample coals. The content of etheric oxygen was < 3.7 per 100 carbon atoms and the cleavage of ether bridges contributed to the formation of preasphaltene. The conversion to hexane solubles in the mild liquefaction reaction correlated well with CH, carbon content of coal, though the conversion to pyridine solubles did not. These results suggest that the formation of oil from preasphaltene is caused by the scission of CH, bridges and some naphthenic CH, bonds. The phenolic OH oxygen-rich portions in coal tended to remain as a residue formed by the condensation reaction of phenolic OH groups.