Free radicals in coals and coal conversion. 3. Investigation of the free radicals of selected macerals upon pyrolysis

✍ Scribed by Leon Petrakis; David W. Grandy

• Publisher: Elsevier Science
• Year: 1981
• Tongue: English
• Weight: 546 KB
• Volume: 60
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/0016-2361(81)90004-1

✦ Synopsis

The nature and concentration of free radicals in natural and pyrolysed samples of several high-purity resinites, vitrinites and fusinites have been determined by electron spin resonance (e.s.r.) spectrometry. Careful measurements of theg-values, linewidths and integrated intensities have been made. The natural concentration of free radicals in the various macerals was measured and found to vary by approximately 5 orders of magnitude. Of the three macerals, the free radical concentration of vitrinites was found to have the greatest dependence upon pyrolysis temperature. The g-values measured offer insight into the chemical nature of the free radicals and how they are altered upon pyrolysis. Interpretation of the data is based upon earlier work on pure macerals and coal pyrolysis. The implications of the nature and behaviour of free radicals in macerals in coal-conversion processes are discussed.