Viscosity is one of the important i

Viscosity is one of the important indicators for evaluating crude oil, and is a factor that cannot be ignored in chemical design, production, and process optimization. As we all know, the residual oil is classified according to the four-component method including: saturation, aroma, gum and asphaltene. Among them, asphaltenes are complex condensed ring aromatic hydrocarbon compounds with no fixed melting point, which have the characteristics of strong polarity, large molecular weight, good temperature sensitivity, etc., so that the residual oil has a high viscosity at normal temperature; Affects residue viscosity; aromatic components are composed of a series of mixed alkanes, naphthenes and condensed aromatic rings, including polar aromatic components and non-polar aromatic components. Polar aromatic components can affect residual oil viscosity and aroma The component can affect the peptizing ability of asphaltenes; the saturated component is composed of aliphatic hydrocarbons and cycloalkyl aromatic hydrocarbons, etc., exists in the residue oil system with low strength and non-polar oils, and large crystals are precipitated at low temperature to make the residue The oil becomes harder and the viscosity becomes larger.