Study On Colloid Stability Of Tahe Atmospheric Residue

Heavy oil, which includes heavy crude oil, atmospheric residue and vacuum residue, covers a large proportion of petroleum trade in our country. The yield of heavy crude oil with high content of resin and asphaltene is increasing. The further study of residue's colloidal property, is important to heavy crude preservation, transportation, and processing. The Mass Fraction Normalized Conductivity method was used to study the colloidal stability variation of Tahe residue samples during thermal reaction with or without additive in this thesis. The coke sizes of samples of different reacted times are measured by Zetasizer Nano ZS particle size analyzer. The result showed that the colloidal stability of residue samples decreased sharply during coke-induction period and had a slow alteration after that. During thermal reaction period, the colloidal stability of the residue plays a decisive role in its coking characteristics. The effect of additive on Tahe atmospheric residue's thermal reaction property was analyzed from the fraction's composition and characteristic's of them perspectives.The samples of thermal reaction with additive were fractioned into six components by liquid chromatogram and the samples'properties were measured. The mean dipole moment was computed from the data of molecular weight, dielectric constant and refractive index The result showed that the dipole moment values decreased one by one as the following order: saturates and light aromatics, heavy aromatics, light resin, middle resin, heavy resin, and n-pentane asphaltene. With adding the additive, the mean dipole moments of asphaltene declined and those of the other five components rised. All samples'viscosities were measured by NDJ-1 rotary viscometer and the viscosities were smaller than that of Tahe residue. Moreover, the visbreaking effect of thermal reaction with additive 30min sample was more obvious than that of thermal reaction 30min sample.