The method of solvent dewaxing for lubricating oil, especially the method of solvent dewaxing for lubricating oil with the mixed solvent of asymmetric ether containing tert butyl and C3 ~ C6 fatty ketone. The application of rotary vane vacuum pump in solvent dewaxing can play an important role. What’s the specific role? Let’s analyze together. Rotary vane vacuum pump is suitable for solvent dewaxing of vacuum distillate oil, especially for solvent dewaxing of vacuum heavy distillate oil.
Different solvents or mixed solvents have an important impact on solvent dewaxing process. One of the objectives of pronock’s technicians is to find the most suitable method of dewaxing solvent, so as to improve the operation performance of dewaxing process, improve the filtration speed and the yield of dewaxing oil. Choosing suitable dewaxing solvent or adding dewaxing assistant to make wax form crystal with uniform size and good dispersion are two important ways to improve filtration speed and yield of dewaxing oil.
rotary vane vacuum pump in solvent dewaxing application
What is the purpose of solvent dewaxing process?
Solvent dewaxing process mainly includes crystallization, filtration, solvent recovery and freezing. Its purpose is to remove paraffin from oil and reduce pour point of lubricating base oil. The process has technical advantages in processing light raw materials, high yield of dewaxed oil and high viscosity index. In order to reduce energy consumption, save operating costs and reduce investment, domestic and foreign lubricant base oil production enterprises all adopt the combined process of solvent dewaxing and wax deoiling. In recent years, they have made great improvements in energy saving, oil and wax yield.
The solvent dewaxing process includes cooling the wax oil and coagulating it into wax, then filtering and cleaning with solvent. Keeping vacuum in the vacuum drum filter makes it possible for the wax oil to pass through the filter screen at a large flow rate under the effect of external pressure. Nitrogen gas is usually used as protective gas to enter the filter and be extracted. The filter oil and nitrogen enter the receiver and the oil is separated; the nitrogen enters the rotary vane vacuum pump through the drum. Such a continuous dewaxing cycle operation.
A method for solvent dewaxing of lubricating oil by using dewaxing assistant is disclosed previously. In this method, the mixture of olefin polymer and alcohol polymer is used as dewaxing assistant, which can improve the filtering speed and the yield of dewaxing oil. However, the mixture of oxygen molecules and double bonds in the auxiliary will bring adverse effects on the stability of wax, which must be removed before it can be used in some strict wax application fields, and the separation of the auxiliary and wax will be a relatively difficult process.
Application of rotary vane vacuum pump in solvent dewaxing this solvent dewaxing method, the specific process is to mix the melted dewaxing raw material and solvent, cool the mixture to the dewaxing temperature, and adopt the multi-point dilution method to add the solvent, filter and separate under the dewaxing temperature to obtain the dewaxing oil and dewaxing wax paste; the solvent is the mixture of asymmetric ether containing tert butyl and C3-C6 fatty ketone Solvent. The filter speed of solvent dewaxing can be increased by 15% ~ 35%, and the yield of dewaxing oil can be increased by 1% ~ 5% when the wax content of dewaxing oil is equal or lower. In the process of solvent dewaxing for lubricating oil, especially for heavy distillate oil, the formation of good crystallization of lubricating oil in the solvent is an important factor to ensure the separation effect of oil and wax, which can improve the filtration speed, reduce the oil content of filter cake, reduce the frequency of warm washing, and improve the yield of dewaxing oil and the treatment capacity of production unit.