Solvent refining method for producing aryl rubber plasticizer or lubricant base oil

Abstract

The invention belongs to the technical field of petroleum refining, and particularly relates to a solvent refining method for producing an aryl rubber plasticizer or lubricating oil base oil, which is characterized in that two pipelines are additionally arranged on an industrial lubricating oil solvent refining device, one pipeline is a pipeline from the bottom of a solvent drying tower to extract liquid, and part of the solvent is returned to an extract liquid system; and the second pipeline is a pipeline from the bottom of the extract oil stripping tower to the extract liquid inlet heating furnace, returning part of the extract oil to the extract liquid system, or from the extract liquid inlet heating furnace to the extract liquid system. The method simultaneously meets the production requirements of environment-friendly rubber plasticizers and common lubricant base oil, the operation of an extract solvent recovery system is not greatly adjusted when the environment-friendly rubber plasticizers are produced, the solvent content in the extract oil is qualified, and the problems that the solvent content in the extract oil exceeds the standard and the cost is low are solved. Or the solvent in the extracted oil does not exceed the standard only by carrying out large process parameter adjustment.

Description

Technical Field

[0001] The present invention belongs to the technical field of petroleum refining, and in particular relates to a solvent refining method for producing aromatic rubber plasticizers or lubricating base oils. Background Art

[0002] Oils used in the process of rubber synthesis or rubber processing are collectively referred to as rubber oils, also known as rubber plasticizers. Rubber plasticizers are one of the important raw materials for rubber processing, and are divided into aromatic type, naphthenic type and paraffinic type. Among them, aromatic type oils have the characteristics of high density, high viscosity, good affinity and excellent processing performance. They have good compatibility with rubber and can endow tires with excellent properties such as good wet skid resistance. This type of oil is represented by lubricating oil solvent extraction oil (DAE), which contains a large amount of polycyclic aromatic hydrocarbon compounds. Polycyclic aromatic hydrocarbons are toxic, such as carcinogenic and damaging the reproductive system. Therefore, they are limited in use by some developed countries. The European Union issued Directive 2005 / 69 / EC on December 9, 2005, requiring that since January 1, 2010, in all tires and rubber products entering the EU market, the total amount of 8 harmful polycyclic aromatic hydrocarbons listed in the rubber oil used shall not exceed 10 milligrams per kilogram, and the content of benzo[a]pyrene (BaP) shall not exceed 1 milligram per kilogram.

[0003] At present, there are mainly two types of domestic environmentally friendly rubber plasticizers: aromatic mineral oil and naphthenic mineral oil. Among them, aromatic mineral oil is mainly applied to tires and related products and oil filling of rubber.

[0004] From the current production technologies of aromatic rubber plasticizers, most of them adopt the solvent refining process or the combined process of hydrotreating - solvent refining. Generally, the raw materials for environmentally friendly rubber plasticizers are the feedstock oil or its extract oil refined by ordinary lubricating oil solvent refining. Therefore, the manufacturers of environmentally friendly rubber plasticizers are also the manufacturers of lubricating oil base oil. Due to the significant differences in the production process conditions between environmentally friendly rubber plasticizers and ordinary lubricating oil, it is very difficult to simultaneously meet the production requirements of environmentally friendly rubber plasticizers and lubricating oil base oil. The main differences are the solvent ratio and the extraction temperature. In industry, the temperature can generally meet the requirements through heat exchange and other means. Generally, a smaller solvent ratio is required for the production of environmentally friendly rubber plasticizers, while a larger solvent ratio is required for the production of lubricating oil base oil. The solvent recovery system of the general lubricating oil solvent refining device is designed according to a larger solvent ratio. Therefore, it is difficult for the solvent recovery system to operate normally under the condition of a smaller solvent ratio. CN 104212479B invented a solvent refining method for producing rubber filling oil or lubricating oil: a solvent pipeline is added to the extract pipeline of the solvent extraction tower, which returns from the bottom of the solvent drying tower to the extract pipeline; when producing rubber plasticizer, the extract at the bottom of the solvent extraction tower is mixed with the solvent returning from the bottom of the solvent drying tower to the extract system to form an extract, and this mixed liquid enters the extract solvent recovery system to obtain the solvent for recycling; when producing lubricating oil base oil, the solvent pipeline of the return extract system is closed. However, it is found in the actual production of environmentally friendly rubber plasticizers that due to the addition of a large amount of solvent furfural in the extract, when recycling the solvent, if the production is carried out under normal operating conditions, it is found that the furfural content in the extract oil exceeds the standard, and process operation adjustment is required, resulting in operational difficulties. There is an urgent need for a method in which the operating conditions of the solvent recovery system are the same as those of ordinary solvent extraction, and the furfural content in the extract oil meets the requirements. Summary of the Invention

[0005] The object of the present invention is to provide a solvent refining method that can produce both environmentally friendly rubber plasticizers and lubricating oil base oil to meet the production needs.

[0006] The object of the present invention is achieved by the following technical solutions:

[0007] The solvent refining method for producing aromatic rubber plasticizer or lubricating oil base oil of the present invention includes a solvent extraction tower, a solvent triple-effect evaporation tower, an extract heating furnace, an extract stripping tower, and a solvent drying tower connected by pipelines, an extraction tower solvent inlet and a feedstock oil inlet connected to the solvent extraction tower, and an extract outlet pipeline connected to the bottom of the extract stripping tower. It is characterized in that, on an industrial lubricating oil solvent refining device, two pipelines are added. One is a pipeline from the bottom of the solvent drying tower to the extract, that is, a pipeline for replenishing furfural from the solvent furfural to the extract, which returns part of the solvent to the extract system; the second pipeline is a pipeline from the bottom of the extract stripping tower to the bottom of the second-effect evaporation tower for the extract containing solvent to enter the extract heating furnace, that is, a pipeline for replenishing extract oil from the extract oil to the bottom of the second-effect evaporation tower, which returns part of the extract oil to the extract system, or a pipeline from the extract containing solvent at the bottom of the second-effect evaporation tower entering the extract heating furnace to the extract system, that is, a pipeline for replenishing extract oil from the extract containing solvent at the bottom of the second-effect evaporation tower to the extract system, which returns part of the extract containing solvent to the extract system.

[0008] When producing an environmentally friendly rubber plasticizer, the mass ratio of the amount of solvent from the bottom of the solvent drying tower to the extract system to the feedstock oil is 0.1:1 to 3.0:1; when producing a common lubricating oil base oil, the pipeline for replenishing furfural from the solvent furfural to the extract is closed, and the amount of its solvent is zero.

[0009] When producing an environmentally friendly rubber plasticizer, the mass ratio of the amount of extract oil returned to the extract entering the extract heating furnace to the feedstock oil is 0.1:1 to 0.5:1; when producing a common lubricating oil base oil, the pipeline for replenishing extract oil from the extract oil to the bottom of the second-effect evaporation tower is closed, and the amount of extract oil returned to the extract entering the extract heating furnace is zero.

[0010] When producing an environmentally friendly rubber plasticizer, the mass ratio of the amount of the extract containing solvent returned from the extract entering the extract heating furnace to the extract system to the feedstock oil is 0.2:1 to 1.0:1; when producing a common lubricating oil base oil, the pipeline for replenishing extract oil from the extract containing solvent at the bottom of the second-effect evaporation tower to the extract system is closed, and the amount returned to the extract system is zero.

[0011] Advantages of the present invention:

[0012] The solvent refining method for producing aromatic rubber plasticizer or lubricating oil base oil of the present invention simultaneously meets the production requirements of environmentally friendly rubber plasticizer and common lubricating oil base oil. When producing an environmentally friendly rubber plasticizer, the operation of the extract solvent recovery system does not require major adjustments, and the solvent content in the extract oil is qualified, solving the technical problem that the solvent content in the extract oil exceeds the standard, or major process parameter adjustments must be made to make the solvent in the extract oil not exceed the standard. Description of the drawings

[0013] Figure 1 This is the process flow chart of the present invention.

[0014] The labels therein are respectively represented as follows: 1. Solvent extraction tower; 2. Solvent triple-effect evaporation tower; 3. Extract heating furnace; 4. Extract stripping tower; 5. Solvent drying tower; 6. Feedstock oil inlet; 7. Solvent inlet of the extraction tower; 8. Raffinate; 9. Extract; 10. Pipeline for replenishing furfural from solvent furfural to the extract; 11. Pipeline for replenishing extract oil from the extract containing solvent at the bottom of the second-effect evaporation tower to the extract system; 12. Extract containing solvent at the bottom of the second-effect evaporation tower; 13. Pipeline for replenishing extract oil from the extract oil to the bottom of the second-effect evaporation tower; 14. Pipeline for the extract oil to leave the unit. Specific embodiments

[0015] The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

[0016] As Figure 1 shown, a solvent refining method for producing aromatic rubber plasticizer or lubricating oil base oil according to the present invention includes a solvent extraction tower 1, a solvent triple-effect evaporation tower 2, an extract heating furnace 3, an extract stripping tower 4, and a solvent drying tower 5 connected by pipelines, an extraction tower solvent inlet 7 and a feedstock oil inlet 6 connected to the solvent extraction tower 1, and an extract oil pipeline 14 leaving the unit connected to the bottom of the extract stripping tower 4. It is characterized in that, on an industrial lubricating oil solvent refining device, two pipelines are added. One is a pipeline from the bottom of the solvent drying tower 5 to the extract 9, that is, the pipeline 10 for replenishing furfural from solvent furfural to the extract, which returns part of the solvent to the extract system to meet the heat balance requirement of the solvent recovery system; the second pipeline is a pipeline from the bottom of the extract stripping tower 4 to the extract containing solvent at the bottom of the second-effect evaporation tower 12 entering the extract heating furnace 3, that is, the pipeline 13 for replenishing extract oil from the extract oil to the bottom of the second-effect evaporation tower, which returns part of the extract oil to the extract system, or a pipeline from the extract containing solvent at the bottom of the second-effect evaporation tower 12 entering the extract heating furnace 3 to the extract system, that is, the pipeline 11 for replenishing extract oil from the extract containing solvent at the bottom of the second-effect evaporation tower to the extract system, which returns part of the extract containing solvent to the extract system to meet the normal operation requirement of this system.

[0017] When producing an environmentally friendly rubber plasticizer, the mass ratio of the amount of solvent from the bottom of the solvent drying tower 5 to the extract system to the feedstock oil is 0.1:1 to 3.0:1; when producing a common lubricating oil base oil, the pipeline 10 for replenishing furfural from solvent furfural to the extract is closed, and the amount of its solvent is zero.

[0018] When producing an environment-friendly rubber plasticizer, the mass ratio of the amount of the extracted oil returned to the extracted oil entering the extracted oil heating furnace 3 to the raw material oil is 0.1:1 to 0.5:1; when producing a common lubricating oil base oil, the pipeline 13 for supplementing the extracted oil at the bottom of the second-effect evaporation tower is closed for the extracted oil, and the amount of the extracted oil returned to the extracted oil entering the extracted oil heating furnace 3 is zero.

[0019] When producing an environment-friendly rubber plasticizer, during the process of the extracted liquid entering the extracted oil heating furnace 3, the mass ratio of the amount of the extracted liquid 12 containing the solvent at the bottom of the second-effect evaporation tower returned to the extracted liquid system to the raw material oil is 0.2:1 to 1.0:1; when producing a common lubricating oil base oil, the pipeline 11 for supplementing the extracted oil at the bottom of the second-effect evaporation tower for the extracted liquid containing the solvent is closed, and the amount of the extracted liquid returned to the extracted liquid system is zero.

[0020] In the present invention, two pipelines are added to an industrial lubricating oil solvent refining device. One pipeline is from the bottom of the solvent drying tower 5 to the extracted liquid 9, that is, the pipeline 10 for supplementing furfural from the solvent furfural to the extracted liquid, which returns part of the solvent to the extracted liquid system to meet the heat balance requirement of the solvent recovery system; the second pipeline is from the bottom of the extracted liquid stripping tower 4 to the pipeline of the extracted liquid 12 containing the solvent at the bottom of the second-effect evaporation tower entering the extracted oil heating furnace 3, that is, the pipeline 13 for supplementing the extracted oil at the bottom of the second-effect evaporation tower from the extracted oil, which returns part of the extracted oil to the extracted liquid system, or from the pipeline of the extracted liquid 12 containing the solvent at the bottom of the second-effect evaporation tower entering the extracted oil heating furnace 3 to the extracted liquid system, that is, the pipeline 11 for supplementing the extracted oil at the bottom of the second-effect evaporation tower for the extracted liquid containing the solvent, which returns part of the extracted liquid containing the solvent to the extracted liquid system to meet the normal operation requirement of the system.

[0021] As shown in the attached drawings, when producing environmentally friendly rubber filling oil: The raw material oil is pumped from the raw material oil inlet 6 to the lower part of the solvent extraction tower 1 through a pipeline by a pump; The solvent is pumped from the bottom of the solvent drying tower 5 to the upper part of the solvent extraction tower 1 through a pipeline from the extraction tower solvent inlet 7 by a pump; The extract 9 at the bottom of the solvent extraction tower 1 is mixed with the solvent furfural from the bottom of the solvent drying tower 5 and enters the first-effect evaporation tower of the solvent triple-effect evaporation tower 2. After evaporating part of the solvent and passing through heat exchange, it enters the second-effect evaporation tower. The extract 12 containing the solvent at the bottom of the second-effect evaporation tower is mixed with part of the extracted oil and then enters the extract heating furnace 3 for heating. Part of the extracted oil is provided by the extracted oil to the pipeline 13 for supplementing the extracted oil at the bottom of the second-effect evaporation tower; The heated extract enters the extract stripping tower 4 after triple-effect evaporation. The extracted oil is obtained at the bottom of the extract stripping tower 4 and is output through the pipeline 14 for the extracted oil to leave the device; Or the extract 12 containing the solvent at the bottom of the second-effect evaporation tower is mixed with the extract 9 at the bottom of the solvent extraction tower 1 and then enters the first-effect evaporation tower of the solvent triple-effect evaporation tower 2. After evaporating part of the solvent and passing through heat exchange, it enters the second-effect evaporation tower. The extract 12 containing the solvent at the bottom of the second-effect evaporation tower enters the extract heating furnace 3 for heating; The heated extract enters the extract stripping tower 4 after triple-effect evaporation. The extracted oil is obtained at the bottom of the extract stripping tower 4. The raffinate 8 at the top of the solvent extraction tower 1 enters the stripping tower after being heated and flash-evaporated in the heating furnace to remove the solvent and obtain the environmentally friendly rubber plasticizer; When producing ordinary lubricating oil, the pipeline 10 for the solvent furfural to supplement the furfural to the extract, the pipeline 11 for the extract containing the solvent at the bottom of the second-effect evaporation tower to supplement the extracted oil to the extract system, and the pipeline 13 for the extracted oil to supplement the extracted oil at the bottom of the second-effect evaporation tower are closed, and the rest is the same as above.

[0022] Example

[0023] Only the examples of aromatic-based rubber plasticizers are given in the examples. When producing ordinary lubricating oil base oil, the pipeline 10 for the solvent furfural to supplement the furfural to the extract, the pipeline 11 for the extract containing the solvent at the bottom of the second-effect evaporation tower to supplement the extracted oil to the extract system, and the pipeline 13 for the extracted oil to supplement the extracted oil at the bottom of the second-effect evaporation tower are closed, and the production operation is the same as that of the original ordinary lubricating oil base oil.

[0024] Example 1

[0025] Using the hydrodesulfurized oil of the naphthenic-based third-stage reduced lubricating oil fraction as the raw material oil, the solvent refining conditions are: the top temperature of the tower is 90 °C, the bottom temperature of the tower is 50 °C, the mass ratio of the solvent furfural to the raw material oil is 0.8:1, and the mass ratio of the solvent amount from the bottom of the solvent drying tower 5 to the extract system to the raw material oil is 2:1; The mass ratio of the amount of the extracted oil returned to the inlet of the extract heating furnace 3 at the extract inlet to the raw material oil is 0.5:1; The operation of the extract solvent recovery system is stable and the process is not adjusted, and the furfural content of the obtained extracted oil is qualified.

[0026] Comparative Example 1

[0027] Using the hydrodesulfurized oil of naphthenic-based vacuum gas oil fraction as the feedstock, the solvent refining conditions are as follows: the top temperature of the tower is 90 °C, the bottom temperature of the tower is 50 °C, the mass ratio of the solvent furfural to the feedstock is 0.8:1, and the mass ratio of the solvent amount from the bottom of the solvent drying tower 5 to the extract system to the feedstock is 2:1; the solvent recovery system of the extract operates normally, but the furfural content in the solvent extract oil exceeds the standard, and the solvent extract oil has a strong furfural smell. Increasing the stripping amount of the extract stripper, the furfural content in the extract often still exceeds the standard.

[0028] Example 2

[0029] Using the solvent extract oil of vacuum gas oil as the feedstock, the solvent refining conditions are as follows: the top temperature of the tower is 60 °C, the bottom temperature of the tower is 40 °C, the mass ratio of the solvent furfural to the feedstock is 1.2:1, and the mass ratio of the solvent amount from the bottom of the solvent drying tower 5 to the extract system to the feedstock is 3:1; the mass ratio of the solvent amount from the bottom of the solvent drying tower 5 to the extract system to the feedstock is 0.8:1; the mass ratio of the amount of the extract returned to the inlet of the extract heating furnace 3 from the extract to the feedstock is 0.1:1; the solvent recovery system of the extract operates normally, and the furfural content in the extract is qualified.

[0030] Comparative Example 2

[0031] Using the solvent extract oil of vacuum gas oil as the feedstock, the solvent refining conditions are as follows: the top temperature of the tower is 60 °C, the bottom temperature of the tower is 40 °C, the mass ratio of the solvent furfural to the feedstock is 1.2:1, and the mass ratio of the solvent amount from the bottom of the solvent drying tower 5 to the extract system to the feedstock is 3:1; the solvent recovery system of the extract operates normally, but the furfural content in the solvent extract oil exceeds the standard, and the solvent extract oil has a strong furfural smell. Increasing the stripping amount of the extract stripper, the furfural content in the extract often still exceeds the standard.

[0032] Example 3

[0033] Using the vacuum gas oil fraction of the second reduced line as the feedstock, the solvent refining conditions are as follows: the top temperature of the tower is 70 °C, the bottom temperature of the tower is 40 °C, the mass ratio of the solvent furfural to the feedstock is 1.0:1, and the mass ratio of the solvent amount from the bottom of the solvent drying tower 5 to the extract system to the feedstock is 1.0:1; the mass ratio of the amount of the extract containing solvent returned to the extract system from the extract entering the heating furnace to the feedstock is 0.5:1; the solvent recovery system of the extract operates normally, and the furfural content in the extract is qualified.

[0034] Comparative Example 3

[0035] Using the second-side reduced lubricating oil fraction as the raw material oil, the solvent refining conditions are as follows: the top tower temperature is 70 °C, the bottom tower temperature is 40 °C, the mass ratio of the solvent furfural to the raw material oil is 1.0:1, and the mass ratio of the solvent amount from the bottom of the solvent drying tower 5 to the extract system to the raw material oil is 1.0:1; the extract solvent recovery system operates normally, but the furfural content in the extract oil exceeds the standard, and the extract oil has a strong furfural smell. Increasing the stripping amount of the extract oil stripper, the furfural content in the extract oil often still exceeds the standard.

[0036] Example 4

[0037] Using the third-side reduced lubricating oil fraction as the raw material oil, the solvent refining conditions are as follows: the top tower temperature is 80 °C, the bottom tower temperature is 50 °C, the mass ratio of the solvent furfural to the raw material oil is 1.2:1, and the mass ratio of the solvent amount from the bottom of the solvent drying tower 5 to the extract system to the raw material oil is 0.8:1; the mass ratio of the solvent-containing extract returned to the extract system from the extract entering the heating furnace to the raw material oil is 0.8:1; the extract solvent recovery system operates normally, and the furfural content in the extract oil is qualified.

[0038] Example 5

[0039] Using the hydrodesulfurized oil of the third-side naphthenic base reduced lubricating oil fraction as the raw material oil, the solvent refining conditions are as follows: the top tower temperature is 70 °C, the bottom tower temperature is 45 °C, the mass ratio of the solvent furfural to the raw material oil is 1.1:1, and the mass ratio of the solvent amount from the bottom of the solvent drying tower 5 to the extract system to the raw material oil is 1.5:1; the mass ratio of the solvent-containing extract returned to the extract system from the extract entering the heating furnace to the raw material oil is 1.0:1; the extract solvent recovery system operates stably, without process adjustment, and the furfural content in the obtained extract oil is qualified.

[0040] In Examples 1 - 5, on the industrial lube oil solvent refining unit, two additional pipelines were installed. One pipeline runs from the bottom of the solvent drying tower 5 to the extract 9, returning part of the solvent to the extract system to meet the heat balance requirements of the solvent recovery system. The second pipeline runs from the bottom of the extract stripping tower 4 to the extract inlet of the extract heating furnace 3, returning part of the extracted oil to the extract system, or from the extract inlet of the extract heating furnace 3 to the extract system, returning part of the extract containing solvent to the extract system to meet the normal operation requirements of the system, without the need for process condition adjustment, and the furfural content in the extracted oil meets the requirements. It can be seen from Comparative Examples 1 - 3 that only the pipeline from the bottom of the solvent drying tower 5 to the extract 9 was installed, returning part of the solvent to the extract system to meet the heat balance requirements of the solvent recovery system. The pipeline from the bottom of the extract stripping tower 4 to the extract inlet of the extract heating furnace 3 was not installed, part of the extracted oil was not returned to the extract system, the pipeline from the extract inlet of the extract heating furnace 3 to the extract system was not installed, and part of the extract containing solvent was not returned to the extract system. In this way, when the solvent recovery system of the extracted oil operates normally, the furfural content in the solvent-extracted oil exceeds the standard, the furfural smell of the extracted oil is strong, and even when the stripping amount of the extracted oil stripping tower is increased, the furfural content of the extracted oil often exceeds the standard.

[0041] The solvent refining method for producing aromatic rubber plasticizer or lube oil base oil of the present invention simultaneously meets the production requirements of environmentally friendly rubber plasticizer and ordinary lube oil base oil. When producing the environmentally friendly rubber plasticizer, the operation of the solvent recovery system of the extract does not require major adjustment, and the solvent content in the extracted oil is qualified, solving the technical problem that the solvent content in the extracted oil exceeds the standard or major process parameter adjustments must be made to make the solvent in the extracted oil not exceed the standard.

Claims

1. A solvent refining method for producing aromatic rubber plasticizer or lubricating oil base oil, comprising a solvent extraction tower, a solvent triple-effect evaporation tower, an extract heating furnace, an extract stripping tower and a solvent drying tower connected by pipelines, an extraction tower solvent inlet and a feedstock oil inlet connected to the solvent extraction tower, and an extracted oil outlet device pipeline connected to the bottom of the extract stripping tower, characterized in that, On the solvent refining unit of industrial lubricating oil, two pipelines are added. One is the pipeline from the bottom of the solvent drying tower to the extract, that is, the pipeline for the solvent furfural to supplement furfural to the extract, which returns part of the solvent to the extract system; the second pipeline is the pipeline from the bottom of the extract stripping tower to the bottom of the second-effect evaporation tower for the extract containing solvent to enter the extract heating furnace, that is, the pipeline for the extracted oil to supplement the extracted oil to the bottom of the second-effect evaporation tower, which returns part of the extracted oil to the extract system, or the pipeline from the bottom of the second-effect evaporation tower for the extract containing solvent to enter the extract heating furnace to the extract system, that is, the pipeline for the extract containing solvent at the bottom of the second-effect evaporation tower to supplement the extracted oil to the extract system, which returns part of the extract containing solvent to the extract system.

2. The solvent refining method for producing aromatic rubber plasticizer or lubricating oil base oil according to claim 1, characterized in that, When producing environmentally friendly rubber plasticizer, the mass ratio of the amount of solvent from the bottom of the solvent drying tower to the extract system to the raw material oil is 0.1:1 to 3.0:1; when producing ordinary lubricating oil base oil, the pipeline for the solvent furfural to supplement furfural to the extract is closed and the amount of the solvent is zero.

3. The solvent refining method for producing aromatic rubber plasticizer or lubricating oil base oil according to claim 1, characterized in that, When producing environmentally friendly rubber plasticizer, the mass ratio of the amount of the extracted oil returned to the extract to enter the extract heating furnace to the raw material oil is 0.1:1 to 0.5:1; When producing ordinary lubricating oil base oil, the pipeline for the extracted oil to supplement the extracted oil to the bottom of the second-effect evaporation tower is closed and the amount of the extracted oil returned to the extract to enter the extract heating furnace is zero.

4. The solvent refining method for producing an aromatic rubber plasticizer or a lubricating oil base oil according to claim 1, characterized in that, When producing environmentally friendly rubber plasticizer, the mass ratio of the amount of the extract containing solvent returned from the extract entering the extract heating furnace to the extract system to the raw material oil is 0.2:1 to 1.0:1; When producing ordinary lubricating oil base oil, the pipeline for the extract containing solvent at the bottom of the second-effect evaporation tower to supplement the extracted oil to the extract system is closed and the amount returned to the extract system is zero.

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