Study On Properties And Structure Of Asphaltenes From Different Heavy Oil

The asphaltene aggregation brings a lot of trouble to heavy oil production and utilization.Since asphaltenes are the most aromatic, polar, large moleculars and complex component inheavy oil, and difficult to study. A variety of heavy oil samples are choosed for study,including Tahe AR, Du-84 heavy oil, BinHua AR, ZhongDong AR and ShengLi VR. Then-heptane asphaltenes are seperated from them and the relationship between the polarity,conglomerating characteristcs, or structure of them are studied. Molecules play an importantrole on the colloidal characteristics of residue. The dielectric constant of n-heptaneasphaltenes in different concentration of benzene solution is measured and the break point toconcentration is considered as the conglomerating concentration. The structure of asphalteneis studied through H-NMR data and the imagine is studied by high resolusion TransmissionElectron Microscope (HRTEM). The solubility of different asphaltenes in benzene-n-heptanemixed solvent is investigated by ultraviolet spectrophotometric method. It can be concludedthat asphaltenes with strong dipole moment is inclined to aggaregate, and had less solubility.The bigger the asphaltenes polarity, the worse the solubility of asphaltenes is. Solubilityparameter of asphaltenes is obtained through Scatchard-Hildebrand equation, and theheteroatoms of different asphaltenes are also researched by XPS and XANES.