Study of serial reaction kinetics and changes of group compositions of petroleum asphalts in continuous heat and air aging

The serial reaction kinetics and the changes of group compositions of Sheng li petroleum asphalt(SPA) and Huansanlian petroleum asphalt(HPA) were studi ed during continuous heat and air aging(CHAA) at 120 similar to 180 degrees C. The test results show that at given temperature the contents of saturat e constituents of two asphalts change very little, aromatic constituents de crease clearly and asphaltenes increase gradually during CHAA. At lower tem peratures(120 similar to 140 degrees C) the contents of resins increase slo wly and no toluene insolubles form obviously, but at higher temperature(180 degrees C) the resins increase at first and then decrease and the toluene insolubles increase much quickly with the CHAA time. The higher the CHAA te mperature, the more evidently the change of asphalt group compositions woul d change. The apparent aging rate constants and the apparent aging activati on energies of various constituents of HPA are 0.004252 similar to 0.02359h (-1) and 29.96 similar to 36.34kJ/mol respectively and those of SPA 0.00608 3 similar to 0.02424h(-1) and 14.67 similar to 15.48kJ/mol respectively. Th e changes of group compositions of petroleum asphalts during CHAA could be well explained by the serial reaction kinetic model presented in this paper . The constituent contents predicted by the model conform reasonably well w ith the experimental ones and the differences between the calculated conten ts and the test ones are generally smaller than 3%.