OXIDATIONS OF COAL BY AQUEOUS SODIUM-HYPOCHLORITE

Oxidations of Illinois No. 6 coal, mostly as insoluble residues of pyridine extractions, by aqueous NaOCl at 30 °C have yielded several products. They range from black, bicarbonate-soluble acids of molecular weight as high as 1000 to nearly colourless, water-soluble acids with molecular weights near 300. Most of the products have a higher ratio of aliphatic/aromatic content than the original coal. The product mix depends mostly on the pH during oxidation and on the state of subdivision of the coal. At pH 13, 96% of the coal introduced is dissolved and 80% of the carbon dissolving is found as the high-molecular-weight acids, which present a promising soluble material for investigation of coal structure. At lower pH, more of the coal structure is destroyed; simple, oxidation-resistant benzene and aliphatic carboxylic acids then become the principal organic products. © 1979.