The Research Of The Theoretical Model Of The Relationship Between The Composition And The Freezing Point Of The Naphthenic Vacuum Distillation

The naphthenic lubricating base oil's low temperature performance is pretty good, because it contains few wax. However, the few wax is one of the most important factors which effecting on freezing point. It is extremely important to dewax and establish a theory model of the naphthenic vacuum distillation between the composition and the freezing point. However, the composition and the structure of the lubricant are so complex that there are almost no qualitative studies on it.The oils structural group composition and hydrocarbon group types were analyzed separately at first. SPSS and the BP methods were used separately as models. According to the results, the BP is good at regarding the non-linear mapping questions. And it can forecast the freezing point accurately.After ketone benzol dewaxing, the low temperature performances of the CFD and the LD vacuum distillation oil improved drastically. The freezing point was reduced almost 50 centigrade. The wax mainly contained n-paraffin. Compared with other hydrocarbon compounds, the density of n-paraffin was smaller, the viscosity was lower, but the freezing point was higher. After removing wax, the freezing point of the dewaxed oil dropped, the density elevated, and the viscosity index rose. It is accurate using the model to forecast the low temperature performances of the dewaxed oil of CFD and LD's distillation vacuum oil. So a model was established in this paper, which can forecast naphthenic base lubricating oil's freezing point accurately.