Free radicals in coal and coal conversions. 8. Experimental determination of conversion in hydroliquefaction

✍ Scribed by Leon Petrakis; David W. Grandy; G.L. Jones

• Publisher: Elsevier Science
• Year: 1983
• Tongue: English
• Weight: 741 KB
• Volume: 62
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/0016-2361(83)90305-8

✦ Synopsis

The results of conversion determinations on the products from Powhatan No.5 coal liquefied in an autoclave and in a high-pressure, high-temperature e.s.r. cavity are reported. Oil, asphaltene and preasphaltene yields, and overall conversion have been determined for Powhatan No.5 coal samples liquefied in tetralin, SRC-II heavy distillate, and naphthalene at temperatures from 400 to480"C in both reactor systems. The concept of reaction severity is introduced and used to formalize the relation between the effect of temperature and reaction time on oil yield and conversion. Oil is the predominant product in liquefaction in tetralin or naphthalene, asphaltene is the major product of liquefaction in SRC-II heavy distillate. Retrogressive reaction (THF-insoluble product formation) becomes severe when SRC-II heavy distillate is the liquefaction solvent and residence time of ~10 min are used at temperatures >45O"C. Preasphaltenes appear to be the only intermediate species in Powhatan No.5 liquefaction.