Teruo Kondo

Free radicals formed in hydrotreated coal liquid and influence of oxygen

The behavior of radicals formed in hydrotreated coal liquid with heat treatment and the influence of oxygen have been investigated by electron spin resonance (E.S.R.) spectroscopy. A set of E.S.R. spectral lines identified as phenalenyl radical appears from 50/sup 0/C as the oil is heated in argon atmosphere. The radical concentration is enhanced with temperature, reaches a maximum between 130 and 150/sup 0/C and then decreases at higher temperatures. The radical is very stable even at 200/sup 0/C for the sample hydrotreated under mild condition, whereas the radical in the sample treated under severe conditions disappears drastically from 150/sup 0/C. When oxygen is introduced in the oil, the radical is converted into semiquinone and/or aryloxy radicals and stable molecules. The treatment in the presence of oxygen at higher temperatures is considered to accompany the formation of other aryloxy radicals by the reaction of aromatic hydrocarbons and oxygen.

An attempt to separate nitrogen compounds

Abstract Coal liquids contain large amounts of nitrogen and oxygen compounds which make the processing of these into fuel uneconomical compared with petroleum. This paper investigates a method of separating the nitrogen compounds as sediments to provide valuable chemicals and clean fuel. Indole contained in coal liquids was photo-oxidized in carbon tetrachloride. The presence of galvinoxyl in the photo-oxidation process affected the formation of sediments in such a way as to suggest a radical reaction process. Whilst increased indole concentration led to increased sediment formation, the percentage yield was lower due to increased solubility of the sediment in highly polar solution. An optimum concentration is therefore indicated.