Abiotic Degradation of Petroleum Asphaltenes

The literature data on the abiotic degradation of asphaltenes are the subject of a systematic review. Such degradation may proceed under natural conditions. In particular, the action of sunlight, especially, ultraviolet radiation, initiates photolysis and photooxidation in asphaltenes leading to an increase in their oxygen content, thereby shifting the hydrophilic-lipophilic balance toward hydrophilicity and increased access of the reaction products for subsequent biotic degradation by microorganisms. The action of ionizing radiation does not lead to a significant change in the molecular composition of asphaltenes since they are highly inert to radiation. An exception is found for the irradiation of asphaltenes by intense electron beams, leading to their considerable degradation.