Abstract: The analysis results of the composition and molecular structure of several typical asphalt molecules show: Several types of asphalt are mainly composed of continental asphalt structure (generally>75%), most asphalt molecules have a high content of heteroatoms, especially sulfur(generally 3%-8%), and there may be multiple heteroatoms in one asphalt molecule. The sulfur in asphaltene is mainly thiophene sulfur(generally>80%), nitrogen is mainly in the form of pentacyclic pyrrole(generally>79%), and the form of oxygen is relatively complex.Experiments using asphaltene and inferior residue with high asphaltene content showed that most of the asphaltene molecules from different sources could be cracked(general cracking rate>77%). The experimental results of inferior residue catalytic hydrothermal conversion showed that asphaltene with five-membered heterocyclic rings was easier to convert, and asphaltene without heterocyclic rings was more difficult. The higher content of five-membered heterocyclic rings (especially five-membered thiophene rings) the asphaltene had, the higher the cracking rates was. Experiments on catalytic hydrothermal conversion of inferior residue with high asphaltene content showed that asphaltene could be cracked efficiently with appropriate reaction temperature(≯435℃), higher hydrogen partial pressure(≮12 MPa), longer reaction time(≮10 h) and higher catalyst concentration(≮1000 μg/g).

Key words: asphaltene, continental asphaltene, thermal conversion in the presence of hydrogen and catalyst, dispersed catalyst, five membered heterocyclic ring