Free radicals in coal and coal conversions. 5. Methodology for the in-situ investigation of free radicals in coal depolymerization under SRC-II preheater/reactor conditions

✍ Scribed by Leon Petrakis; D.W. Grandy; R.G. Ruberto

• Publisher: Elsevier Science
• Year: 1981
• Tongue: English
• Weight: 477 KB
• Volume: 60
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/0016-2361(81)90041-7

✦ Synopsis

In a continuing series of publications, a systematic investigation of the free radicals during coal depolymerization under SRC-II preheater/reactor conditions has been made. A uniquely designed electron spin resonance (e.s.r.) cavity allows the monitoring of free radicals and how they are affected by residence time, temperature and pressure changes. This paper summarizes the methodology that has been developed to study systematically free radical formation and behaviour in-situ during coal liquefaction. The methodology involved is to be used extensively in subsequent papers that examine in detail the manifold parameters that affect coal depolymerization. Also, results are given on the dependence of free radicals on temperature, pressure and gases in the presence of tetralin. The free radical concentration can be measured 3-4 min after the initiation of the heating process to an accuracy of * 20%, while the process variables may cause several-fold changes in the free radical concentration. ~~~~~. ~~~ ~~~ -* From Pt. Powhatan in southeastern Ohio