Chemical composition of acid-pond tar and asphalts obtained from it

Investigations of the group composition of ATA (acid-tar asphalts) and PRA (petroleum road asphalts) obtained from acid and straight-run tars, respectively, showed that structure formation of ATA asphalts are formed mainly from resins. Oils take virtually no part in formation of asphaltenes. Formation of PRA asphalts proceeds by the generally accepted scheme oils-resins-asphaltenes. Direct formation of asphaltenes from oils has not been eliminated. Paraffin and naphthene hydrocarbons are inert in oxidation both of ATA and of PRA asphalts. Various structural groups were determined quantitatively by IR spectroscopy. Structural formation in asphalts involves tertiary carbon atoms and is characterized by increase of the degree of aromatization. ATA asphalts have higher contents of paraffins and naphthenes than PRA asphalts, and their contents of naphthenes are higher by a factor of 2-3. The paraffins in PRA are less branched. The degree of aromatization of ATA is also lower. 8 references, 2 figures, 4 tables.