Abstract: This paper mainly studies the causes and the mechanisms of how ultrasonic waves affect and change the resin and the asphaltene in residue. The results show that initial temperature of ultrasoinc operation has the greatest effect on the distribution of the saturate, aromatic, resin, asphaltene, and the ultrasoinc power takes the second, while operation time has no distinct effect. According to the infrared spectroscopic analysis, the types of functional groups of asphaltene and resins do not change significantly, merely the contents change slightly. Proton nuclear magnetic resonance analysis show that free heteroatoms produced from resin cyclize with the side chains on asphaltene surface and heterocyclic unsaturated compounds are formed on asphaltene structure at low temperature and low power, thus these effects are conducive to asphaltene polymerization. High temperature and high power promote the aromatic structure of asphaltene to open the ring and form side chain, which is favorable for asphaltene cracking. The aromatic compounds of the resin pyrolysis is adsorbed on its surface, while there is a certain limit to this adsorption at high temperature and high power.

Key words: asphaltene, resin, residue, polymerization, pyrolysis