STUDY OF THE NITRIC ACID OXIDATION OF PETROLEUM ASPHALTENES.

Petroleum asphaltenes have been subjected to progressive oxidation using 70% nitric acid, and the reaction products monitored by elemental analysis. Gas chromatographic-mass spectroscopic (gc-ms) analysis of products from exhaustive oxidation has also been carried out. The oxidation of asphaltenes rapidly produces both water-soluble and water-insoluble oxygen rich species, some of which can be attributed to products of an aromatic nitration reaction. Massive degradation, in the course of which material is steadily converted to water soluble products, continues with prolonged reaction time. The widespread formation of carboxylic acids accounts only in part for the large oxygen uptake, and the gc-ms evidence suggests that a number of other oxygenated structures, in which carbonyl and hydroxyl groups are likely to be most important, are formed as stable intermediates.