阅读说明：本技术 一种降低润滑油基础油浊点的方法 (Method for reducing cloud point of lubricating oil base oil ) 是由 全辉 张志银 赵威 孙国权 刘林东 于 2019-10-30 设计创作，主要内容包括：本发明公开了一种降低润滑油基础油浊点的方法,所述方法为润滑油基础油原料进入吸附降浊区,在吸附剂存在下进行处理,然后得到浊点合格的润滑油基础油。本发明方法通过采用吸附降浊工艺可以大幅降低润滑油基础油的浊点,且同时产品收率较高。(The invention discloses a method for reducing the cloud point of lubricating base oil, which comprises the steps of enabling a lubricating base oil raw material to enter an adsorption and turbidity reduction area, carrying out treatment in the presence of an adsorbent, and then obtaining the lubricating base oil with qualified cloud point. The method can greatly reduce the cloud point of the lubricating oil base oil by adopting an adsorption turbidity reduction process, and has higher product yield.)

1. A method for reducing the cloud point of lubricating base oil comprises the steps of enabling a lubricating base oil raw material to enter an adsorption turbidity reduction zone, carrying out treatment in the presence of an adsorbent, and obtaining the lubricating base oil with qualified cloud point.

2. A method of reducing the cloud point of a lubricant base oil according to claim 1, wherein: the cloud point of the lubricating oil base oil raw material is-20 ℃ to +50 ℃, and preferably-10 ℃ to +40 ℃.

3. A method of reducing the cloud point of a lubricant base oil according to claim 2, wherein: the pour point of the lubricant base oil feedstock is less than 0 deg.C, preferably less than-6 deg.C.

4. A method of reducing the cloud point of a lubricant base oil according to claim 2 or 3, wherein: the kinematic viscosity at 100 ℃ of the lubricating oil base oil raw material is 2.0mm²/s～200mm²S, preferably 3.5mm²/s～100mm²S; the viscosity index is greater than 10, preferably greater than 40.

5. A method of reducing the cloud point of a lubricant base oil according to claim 1, wherein: and further distilling and separating the obtained lubricating oil base oil with qualified cloud point to obtain lubricating oil base oil products with different viscosity grades.

6. A method of reducing the cloud point of a lubricant base oil according to claim 1, wherein: the adsorbent adopted in the adsorption turbidity-reducing zone is carbamide.

7. A method of reducing the cloud point of a lubricant base oil according to claim 6, wherein: the particle size of the carbamide is 0.1-5 mm.

8. A method of reducing the cloud point of a lubricant base oil according to claim 6, wherein: the purity of the carbamide is not less than 90%, preferably not less than 95%; the nitrogen content of the carboxamide is not less than 46% by weight, preferably not less than 46.5% by weight.

9. A method for reducing the cloud point of a lubricant base oil according to any one of claims 1, 6, 7 or 8 wherein: the adsorbent carbamide is pretreated before use, wherein the pretreatment is to treat the carbamide for 2-6 hours under the conditions that the pressure is 1-200 mm Hg, preferably 10-40 mm Hg, the temperature is 80-130 ℃, and preferably 90-110 ℃.

10. A method for reducing the cloud point of a lubricant base oil according to claim 9, wherein: the water content in the carbamide after pretreatment is 0.10-0.50 wt%.

11. A method of reducing the cloud point of a lubricant base oil according to claim 1, wherein: the reaction conditions of the adsorption turbidity-reducing zone are as follows: the operation pressure is normal pressure to 1MPa, preferably normal pressure, the adsorption temperature is 0-120 ℃, and preferably 5-30 ℃; the volume airspeed is 0.1-10.0 h^-1Preferably 1.0 to 5.0 hours^-1。

12. A method of reducing the cloud point of a lubricant base oil according to claim 1, wherein: the adsorption turbidity reduction zone adopts a lower feeding mode.

13. A method of reducing the cloud point of a lubricant base oil according to claim 1, wherein: and a first adsorbent bed layer and a second adsorbent bed layer are sequentially arranged in the adsorption turbidity reduction zone according to the material flowing direction.

14. A method for reducing the cloud point of a lubricant base oil according to claim 13, wherein: the first adsorbent bed layer is filled with carbamide with the grain diameter of 3.0-5.0 mm, and the second adsorbent bed layer is filled with carbamide with the grain diameter of 0.2-1.0 mm.

15. A method of reducing the cloud point of a lubricant base oil according to claim 13 or 14, wherein: the volume ratio of the first adsorbent bed layer to the second adsorbent bed layer is 5.0: 1-0.2: 1, and preferably 2.0: 1-1.0: 1.

Technical Field

The invention belongs to the technical field of lubricating oil processing, and particularly relates to a method for reducing the cloud point of lubricating oil base oil.

Background

Various dewaxing and conversion high pour point hydrocarbon refinery techniques, such as solvent dewaxing, catalytic dewaxing, etc., have long been developed and used to improve the quality of lubricant base oil products. However, these conventional techniques have not only low yields of the desired products but also a serious influence on the viscosity index of the lubricating oil. Isodewaxing techniques developed in the nineties of the last century maintained higher lubricant base oil yields by isomerization of high molecular weight normal paraffins to lower the freezing point of the feedstock while retaining other well-behaved iso-hydrocarbons in the lubricant oil fraction. When the isomerization dewaxing process is adopted to process high-wax content or heavy wax content raw materials, macromolecular paraffin with lower isomerization degree is generated, the paraffin has high condensation point, exists in the base oil in the form of floccule at normal temperature, causes the appearance of the base oil to be turbid, greatly improves the cloud point of the base oil and influences the service performance of the base oil.

US6699385 discloses a process for producing a low cloud point base oil using F-T wax or bright stock, which comprises prefractionating the raw materials and then isodewaxing the resulting light distillate to produce a low cloud point base oil.

CN 1690191759 discloses a process for producing base oil with low cloud point by using an isomerization dewaxing-solvent dewaxing method. CN1524929 discloses a method for producing base oil with low cloud point by using solvent pre-dewaxing-hydrotreating-isodewaxing method. In both methods, the cloud point of the base oil is reduced by adopting a solvent dewaxing process, but the process is complex and the effect of reducing the cloud point is not good.

US 6051129 discloses a process for producing a low cloud point lubricant base oil by isodewaxing with a combined catalyst comprising EU-1, ZSM-48, SSZ-32 molecular sieves, respectively.

Some prior art techniques for reducing cloud point are disclosed above, but the cloud point reducing effect is not good or the yield of lubricant base oil products is low.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a method for reducing the cloud point of lubricating oil base oil. The method can greatly reduce the cloud point of the lubricating oil base oil by adopting an adsorption turbidity reduction process, and has higher product yield.

The invention provides a method for reducing the cloud point of lubricating base oil, which is characterized in that a lubricating base oil raw material enters an adsorption and turbidity reduction zone and is treated in the presence of an adsorbent, and then the lubricating base oil with qualified cloud point is obtained.

In the method for reducing the cloud point of the lubricating base oil, the properties of the lubricating base oil are as follows: the cloud point is-20 to +50 ℃, preferably-10 to +40 ℃; the pour point is less than 0 ℃; kinematic viscosity at 100 ℃ of 2.0mm²/s～200mm²S, preferably 3.5mm²/s～100mm²S; viscosity index greater than 10, preferablyGreater than 40; preferably less than-6 deg.c.

In the method for reducing the cloud point of the lubricating base oil, the obtained lubricating base oil with qualified cloud point is further distilled and separated to obtain lubricating base oil products with different viscosity grades, the distillation can adopt a reduced pressure distillation process, and the conditions of the reduced pressure distillation are as follows: the pressure at the top of the distillation tower is 5-40 mm Hg, preferably 5-15 mm Hg; the temperature of the bottom of the distillation tower is 250-360 ℃, and preferably 300-340 ℃.

In the method for reducing the cloud point of the lubricating oil base oil, the adsorbent adopted in the adsorption and turbidity reduction zone is carbamide which is white and semitransparent particles with the particle size of 0.1-5 mm; the purity of the carboxamide is not less than 90%, preferably not less than 95%; the nitrogen content of the carboxamide is not less than 46% by weight, preferably not less than 46.5% by weight. Commercially available products can be used.

In the method for reducing the cloud point of the lubricating oil base oil, the adsorbent carbamide adopted in the adsorption turbidity reduction zone is preferably further pretreated before use, the pretreatment is to treat the carbamide for 2-6 hours under the conditions that the pressure is 1-200 mm Hg, preferably 10-40 mm Hg, the temperature is 80-130 ℃, preferably 90-110 ℃, and the water content in the pretreated carbamide is controlled to be 0.10-0.50 wt%.

In the method for reducing the cloud point of the lubricating oil base oil, the adsorption and turbidity reduction zone can be operated continuously or intermittently, preferably continuously.

In the method for reducing the cloud point of the lubricating oil base oil, the reaction conditions of the adsorption and turbidity reduction zone are as follows: the operation pressure is normal pressure to 1MPa, preferably normal pressure, the adsorption temperature is 0-120 ℃, and preferably 5-30 ℃; the volume airspeed is 0.1-10.0 h^-1Preferably 1.0 to 5.0 hours^-1。

In the method for reducing the cloud point of the lubricating oil base oil, the adsorption and turbidity reduction zone is provided with more than one reactor, the reactor can be one or more of a fixed bed reactor, a fluidized bed reactor and a moving bed reactor, and the fixed bed reactor is preferably adopted.

In the method for reducing the cloud point of the lubricating base oil, the adsorption and turbidity-reducing zone preferably adopts a lower feeding mode, and the lubricating base oil with the cloud point reduced is discharged from the upper part of the reactor.

In the method for reducing the cloud point of the lubricating oil base oil, a first adsorbent bed layer and a second adsorbent bed layer are sequentially arranged in an adsorption turbidity reduction zone according to the material flowing direction; the first adsorbent bed layer is filled with carbamide with the particle size of 3.0-5.0 mm, the second adsorbent bed layer is filled with carbamide with the particle size of 0.2-1.0 mm, and the volume ratio of the first adsorbent bed layer to the second adsorbent bed layer is 5.0: 1-0.2: 1, preferably 2.0: 1-1.0: 1. The first adsorbent bed layer and the second adsorbent bed layer can be arranged in one reactor, or more than one reactor can be respectively and independently arranged, the reactor can be one or more of a fixed bed reactor, a fluidized bed reactor and a moving bed reactor, and the fixed bed reactor is preferably adopted.

Compared with the prior art, the method for reducing the cloud point of the lubricating oil base oil has the following advantages:

1. in the method for reducing the cloud point of the lubricating oil base oil, the adsorption turbidity-reducing area is arranged, the solid carbamide adsorbent is used in the adsorption turbidity-reducing area, and the carbamide shows excellent shape-selective adsorption capacity on the normal paraffin to remove a very small amount of unreacted normal paraffin in the lubricating oil raw material. In the method of the invention, only a very small amount of unreacted n-alkane in the lubricating oil base oil raw material affects the cloud point of a base oil product, and the applicant finds that the carbamide still has certain shape selective adsorption capacity on the n-alkane under the normal temperature solid state, and the carbamide is pretreated, so that not only can moisture affecting the adsorption capacity of the carbamide be removed, but also the generation of biuret can be prevented. In particular, the pretreated carboxamides are effective for adsorbing very small amounts of n-alkanes.

2. In the method for reducing the cloud point of the lubricating oil base oil, the adsorption and turbidity reduction zone adopts a lower feeding and adsorbent grading filling mode, so that the influence of the sidewall effect on the adsorption effect can be avoided, the adsorption effect is further improved, the problem of high cloud point of the base oil is solved by utilizing a shape selective adsorption method under mild operation conditions, the process is simple, and the yield of the lubricating oil base oil product is high.

Detailed Description

The following examples are provided to illustrate the details and effects of the method of the present invention. The following examples further illustrate the process provided by the present invention, but do not limit the scope of the invention.

Example 1

In example 1, F-T4 cSt base oil was used as the feedstock, and the specific properties of the feedstock are shown in Table 1. The particle size of the adsorbent carbamide is 1.5 mm; the purity of the carbamide is 95 percent, the nitrogen content of the carbamide is 49 percent by weight, and the water content of the carbamide is 6.28 percent by weight. The adsorption turbidity reduction zone adopts a lower feeding mode. The reaction conditions in the adsorption and turbidity reduction zone and the properties of the lubricating base oil obtained after treatment are shown in Table 2.

Example 2

Compared with example 1, the difference is that the raw material is F-T6 cSt base oil listed in Table 1, and the specific properties are shown in Table 1. The adsorbent is pretreated carbamide, the pretreatment condition is that the pressure is 15 mm Hg, the temperature is 80 ℃, and the treatment is carried out for 3 hours, so that the grain size of the pretreated carbamide is 1.5 mm; the purity of the carbamide is 95 percent, the nitrogen content of the carbamide is 49.2 percent by weight, and the water content of the carbamide is 0.28 percent by weight. The adsorption turbidity reduction zone adopts a lower feeding mode. The reaction conditions in the adsorption and turbidity reduction zone and the properties of the lubricating base oil obtained after treatment are shown in Table 2.

Example 3

Compared with example 1, the difference is that the raw material is DAO-1 listed in Table 1, and the specific properties are shown in Table 1. A first adsorbent bed layer and a second adsorbent bed layer are sequentially arranged in the adsorption turbidity reduction zone according to the material flowing direction; the first adsorbent bed is filled with carbamide with the particle size of 5.0 mm, the second adsorbent bed is filled with carbamide with the particle size of 2.0mm, and the volume ratio of the first adsorbent bed to the second adsorbent bed is 2: 1. the adsorption turbidity reduction zone adopts a lower feeding mode. The adsorbents filled in the first adsorbent bed layer and the second adsorbent bed layer are all pretreated carbamide, the pretreatment conditions are all 160 mm Hg, the temperature is 125 ℃, and the treatment is carried out for 6 hours. The grain diameter of the carbamide filled in the first adsorbent bed layer obtained after pretreatment is 5.0 mm, the purity of the carbamide is 92 percent, the nitrogen content of the carbamide is 48.0 percent by weight, and the water content of the carbamide is 0.17 percent by weight; the second adsorbent bed obtained after pretreatment was loaded with carbamide having a particle size of 5.0 mm, a carbamide purity of 95%, a carbamide nitrogen content of 49.1wt%, and a carbamide water content of 0.13 wt%. The reaction conditions in the adsorption and turbidity reduction zone and the properties of the lubricating base oil obtained after treatment are shown in Table 2.

Example 4

Compared with example 1, the difference is that the raw material is DAO-2 listed in Table 1, and the specific properties are shown in Table 1. A first adsorbent bed layer and a second adsorbent bed layer are sequentially arranged in the adsorption turbidity reduction zone according to the material flowing direction; the first adsorbent bed is filled with carbamide with the grain diameter of 4.0 mm, the second adsorbent bed is filled with carbamide with the grain diameter of 1.0 mm, and the volume ratio of the first adsorbent bed to the second adsorbent bed is 1: 1. the adsorption turbidity reduction zone adopts a lower feeding mode. The adsorbents filled in the first adsorbent bed layer and the second adsorbent bed layer are all carbamide which is pretreated, wherein the pretreatment condition is that the pressure is 100 mmHg, the temperature is 100 ℃, and the treatment is carried out for 2 hours. The grain diameter of the carbamide filled in the first adsorbent bed layer obtained after pretreatment is 1.0 mm, the purity of the carbamide is 96 percent, the nitrogen content of the carbamide is 51.2 percent by weight, and the water content of the carbamide is 0.39 percent by weight; the second adsorbent bed obtained after pretreatment was loaded with carbamide of 4.0 mm particle size, 91% carbamide purity, 48.3% carbamide nitrogen content and 0.42% carbamide water content. The reaction conditions in the adsorption and turbidity reduction zone and the properties of the lubricating base oil obtained after treatment are shown in Table 2.

TABLE 1 Properties of the raw materials

TABLE 2 Process conditions and reaction results for the adsorption-turbidity-reducing zone