A method for preparing a bright stock

Abstract

The application discloses a preparation method of bright oil and belongs to the technical field of petroleum chemical industry. The method comprises the following steps: sending deasphalted oil after furfural extraction and ketone-benzene dewaxing into a heating furnace through a raw material buffer tank for temperature rising, then removing light components through an evaporation tower; then sending the deasphalted oil into an electric refining tank for denitrogenation reaction with a denitrogenation agent; after denitrogenation, the raw material oil enters an adsorbent tank for adsorption reaction with a low-temperature high-efficiency adsorbent; the raw material oil mixed with the adsorbent enters a degassing tank and a filter machine in sequence for vacuum degassing and plate-frame filtration, so that the adsorbent is removed, and the bright oil is obtained. The low-temperature denitrogenation adsorption process can further remove a small amount of residual gum, asphaltene, naphthenic acid, sulfonic acid, residual solvent, moisture and mechanical impurities and the like in the dewaxed oil, the dewaxed oil is deeply refined, high-quality bright oil is obtained, and the energy consumption of the device is further reduced.

Description

Technical Field

[0001] This invention relates to the field of petrochemical technology, specifically to a method for preparing bright oil. Background Technology

[0002] The most traditional method for producing lubricating oil base oils is to use vacuum-pressed wax oil as raw material and employ the "old three-step" process for solvent refining. This process includes three stages: furfural refining, ketone-benzene dewaxing, and clay refining. This process is characterized by low cost, high yield of high-viscosity base oils, and the simultaneous production of high-melting-point paraffin wax as a byproduct. Furthermore, compared to the currently widely used hydrotreating method, the base oil produced by solvent refining retains a small amount of aromatics, thus exhibiting strong solubility for oxidation products and additives. Therefore, the "old three-step" process still holds an irreplaceable position in the production of lubricating oil base oils.

[0003] Bright oil is a high-viscosity lubricating oil base oil, produced from deasphalted oil. Because deasphalted oil has a larger molecular weight than vacuum-pressed wax oil, it is more difficult for adsorbent molecules to form intermolecular interactions, making it challenging to achieve good adsorption results using traditional clay refining processes. Yao Qing et al., in their article "Energy-Saving Application of Low-Temperature Adsorption Technology in Lubricating Oil Refining Production," proposed using highly efficient low-temperature adsorbents. These adsorbents, with their high activity, can efficiently adsorb polar substances in the raw materials, not only improving the quality of lubricating oil products but also effectively reducing energy consumption and adsorbent consumption during production, thus minimizing environmental pollution. However, this technology has not yet been applied in the production of bright oil, representing a technological gap. Summary of the Invention

[0004] To address the above problems, this invention provides a method for preparing a gloss oil.

[0005] The technical solution adopted in this invention is: A method for preparing a gloss varnish includes the following steps: (1) The deasphalted oil after furfural extraction and ketone-benzene dewaxing enters the raw material buffer tank; (2) The raw oil in the raw material buffer tank is pumped into the heating furnace and then enters the evaporation tower to carry out the light component removal reaction to remove moisture and light components from the raw material; (3) The raw oil after light removal in the evaporation tower is pumped into the electrorefining tank and reacted with the denitrifying agent to remove the alkaline nitrogen from the raw material; (4) After denitrification, the raw oil enters the adsorbent tank and undergoes an adsorption reaction with a low-temperature high-efficiency adsorbent to remove residual naphthenic acid, solvent, water and mechanical impurities from the raw oil. (5) The raw oil mixed with adsorbent enters the degassing tank and filter in sequence for vacuum degassing and plate and frame filtration to remove the adsorbent and obtain bright oil.

[0006] Furthermore, in step (1), the raw oil in the raw material buffer tank has an alkaline nitrogen content of 100-150 ppm, a color of 4-5, and an acid value of 0.01-0.05 mg KOH / g. This can further improve product quality and reduce production energy consumption.

[0007] Furthermore, in step (2), the temperature of the evaporation tower is 135~145℃, the pressure at the top of the tower is -0.09~-0.05MPa, and the preferred evaporation time is 30~60 minutes. This can avoid the high-temperature oxidation and deterioration of the oil, while ensuring the stable operation of subsequent denitrification and adsorption processes.

[0008] Further, in step (3), the denitrifying agent is a WSQ series high-selectivity denitrifying agent, preferably WSQ-4 denitrifying agent; the mass ratio of the denitrifying agent to the raw oil is 0.6%~1.0%, and the denitrification reaction temperature is 85~110℃. The denitrification reaction time is preferably 30~50 minutes, which can selectively adsorb polar impurities such as complexes, is easy to desorb, and has good selectivity.

[0009] Further, in step (4), the adsorbent is a porous inorganic mineral composite adsorbent, preferably BLS2000 type low temperature high efficiency adsorbent, the mass ratio of the adsorbent to the raw oil is 0.7%~1.2%, the adsorption reaction temperature is 100~140℃, and the adsorption reaction is preferably 30~50 minutes.

[0010] Porous inorganic mineral composite adsorbents have a large specific surface area and a reasonable pore structure. They can efficiently adsorb nitrogen complexes, colloids and colored impurities at low temperatures, with high adsorption capacity, low reagent dosage and low energy consumption.

[0011] Furthermore, in step (5), the temperature for vacuum degassing is 120~130℃, and the vacuum degree is 0.07~0.08MPa. Under these conditions, it is possible to ensure that the gas and trace amounts of water are fully removed, while avoiding high-temperature oxidation and coking of the oil.

[0012] Furthermore, the plate and frame filter includes primary and secondary filtration. The primary filtration has a filtration accuracy of 5μm, and the secondary filtration has a filtration accuracy of 2μm. The temperature for primary filtration is 120~130℃, and the pressure is 0.3~0.5Mpa; the temperature for secondary filtration is 120~130℃, and the pressure is 0.3~0.5Mpa. This two-stage filtration system intercepts large particulate impurities and a small amount of colloids through primary filtration, protecting the secondary fine filter media and preventing clogging. Secondary filtration deeply removes fine solid particles and trace amounts of adsorbent powder, ensuring the transparency and cleanliness of the oil and meeting the requirements for finished lubricating oil.

[0013] Furthermore, it also includes: the raw oil obtained in step (2) is cooled by heat exchange with the raw oil obtained in step (4) and then enters the electrorefining tank for denitrification reaction; the raw oil obtained in step (4) is heated by heat exchange with the raw oil obtained in step (2) and then enters the degassing tank for vacuum degassing. This further reduces energy consumption and improves the degassing effect.

[0014] Further, in step (1), the deasphalted oil has a viscosity of 22~24 mm2 / s at 100℃, a pour point of 45~50℃, an acid value of 0.01~0.05 mgKOH / g, an alkaline nitrogen content of 200~300 ppm, a carbon residue of 1.3%~1.5%, a color of 4.5~5.5, and a flash point of 260~290℃.

[0015] The physical properties of this deasphalted oil are compatible with this process, ensuring stable and smooth material transport, reaction, and filtration. It can fully utilize the purification effects of denitrifying agents and adsorbents, effectively improving the overall quality of the finished product and production safety while controlling reagent consumption and reducing oil loss.

[0016] Further, in step (5), the obtained bright oil has a viscosity of 23~25 mm2 / s at 100℃, a pour point of -9~-12℃, an acid value of 0.01~0.03 mgKOH / g, an alkaline nitrogen content of 45~75 ppm, a carbon residue of 0.45%~0.5%, a color of 3.0~3.5, and a flash point of 270~285℃.

[0017] The beneficial effects of this invention are: 1. The present invention adopts a process flow of drying in an evaporation tower before entering the denitrification and adsorption process, which can significantly reduce the water vapor and impurities brought into the denitrification and adsorption system, avoid water vapor and impurities interfering with the performance of the denitrifying agent and adsorbent, thereby effectively improving the efficiency of the denitrification and adsorption process, reducing the amount of denitrifying agent and adsorbent used, and improving product quality.

[0018] 2. This invention uses deasphalted oil obtained through furfural extraction and ketone-benzene dewaxing as raw material, and employs a low-temperature adsorption refining process to prepare bright oil. By utilizing the high selectivity of the adsorbent, small amounts of residual gums, asphaltenes, naphthenic acids, sulfonic acids, residual solvents, moisture, and mechanical impurities in the dewaxed oil are further removed, thereby refining the dewaxed oil to obtain high-quality bright oil. Attached Figure Description

[0019] Figure 1 This is a flow chart of the low-temperature adsorption process for bright oil according to the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and preferred embodiments.

[0021] Unless otherwise specified, all raw materials used in this invention are purchased from the market.

[0022] The following examples were carried out on the production line of this application. The reaction process is a continuous reaction, and each reaction time is the total time from when the material enters the reaction equipment to when it flows out of the reaction equipment. Example 1

[0023] A method for preparing a gloss varnish, comprising the following steps: (1) 15t / h of dewaxed oil at a temperature of about 90℃ is used as raw material to enter the raw material buffer tank, and is pumped into the heating furnace F-101 to be heated to 135℃ before entering the evaporation tower. The temperature of the evaporation tower is controlled at 135℃ and the pressure at the top of the tower is -0.09MPa. After evaporation for 30 minutes, the raw material oil after light removal is obtained. (2) The raw oil after light removal is mixed with WSQ-4 denitrifying agent through a pipeline mixer and then pumped into an electric refining tank. The mass ratio of denitrifying agent to raw oil is controlled at 0.6%, the reaction temperature is 85℃, and the denitrification reaction is carried out for 40 minutes to obtain denitrified raw oil. (3) After denitrification, the raw oil enters the settling tank D-202 for settling and separation to remove the remaining denitrification tailings; after separation, the oil phase and BLS2000 type low temperature high efficiency adsorbent enter the adsorption tank together, and the mass ratio of adsorbent to raw oil is controlled at 0.7, the reaction temperature is 100℃, and the adsorption reaction is carried out for 40 minutes. (4) After the adsorption reaction is completed, the raw oil is pumped into a degassing tank and degassed under vacuum for 45 minutes at 120°C and 0.07 MPa. Then, it is pumped into heat exchanger E-101 for heating and then into a primary plate and frame filter (filtration accuracy of 5 μm). After filtration for 2 minutes at 120°C and 0.3 MPa, it enters buffer tank D-105. Then, it is pumped into a secondary plate and frame filter (filtration accuracy of 2 μm) and filtered for 3 minutes at 120°C and 0.3 MPa. Finally, it enters buffer tank D106 to obtain bright oil. The yield of bright oil is 99.5%. The properties of the raw oil and the obtained bright oil are shown in Table 1. Example 2

[0024] A method for preparing a gloss varnish, comprising the following steps: (1) 15t / h of dewaxed oil at a temperature of about 90℃ is used as raw material to enter the raw material buffer tank, and is pumped into the heating furnace F-101 to be heated to 145℃ before entering the evaporation tower. The temperature of the evaporation tower is controlled at 145℃ and the pressure at the top of the tower is -0.05MPa. The oil is continuously evaporated for 50 minutes to obtain the raw material oil after light removal. (2) The raw oil after light removal is mixed with WSQ-4 denitrifying agent through a pipeline mixer and then pumped into an electric refining tank. The mass ratio of denitrifying agent to raw oil is controlled at 1.0%, the reaction temperature is 110℃, and the denitrification reaction is carried out for 40 minutes to obtain denitrified raw oil. (3) After denitrification, the raw oil enters the settling tank D-202 for settling and separation to remove the remaining denitrification tailings; after separation, the oil phase and BLS2000 type low temperature high efficiency adsorbent enter the adsorption tank together, and the mass ratio of adsorbent to raw oil is controlled at 1.2%, the reaction temperature is 140℃, and the adsorption reaction is carried out for 40 minutes. (4) After the adsorption reaction is completed, the raw oil is pumped into the degassing tank and vacuum degassed for 35 minutes at a temperature of 130℃ and a vacuum degree of 0.08MPa. Then it is pumped into the heat exchanger E-101 for heating and then into the first-stage plate and frame filter (filtration accuracy of 6μm). After filtration for 3 minutes at a temperature of 130℃ and a pressure of 0.5MPa, it enters the buffer tank D-105. Then it is pumped into the second-stage plate and frame filter (filtration accuracy of 3μm). After filtration for 3 minutes at a temperature of 120℃ and a pressure of 0.3MPa, it enters the buffer tank D106 to obtain bright oil. The yield of bright oil is 99.6%.

[0025] The properties of the raw oil and the resulting bright oil are shown in Table 1. Example 3

[0026] A method for preparing a gloss varnish, comprising the following steps: (1) 15t / h of dewaxed oil at a temperature of about 90℃ is used as raw material to enter the raw material buffer tank, and is pumped into the heating furnace F-101 to be heated to 140℃ before entering the evaporation tower. The temperature of the evaporation tower is controlled at 140℃ and the pressure at the top of the tower is -0.07MPa. The oil is continuously evaporated for 40 minutes to obtain the raw material oil after light removal. (2) The raw oil after light removal is mixed with WSQ-4 denitrifying agent through a pipeline mixer and then pumped into an electric refining tank. The mass ratio of denitrifying agent to raw oil is controlled at 0.8%, the reaction temperature is 100℃, and the denitrification reaction is carried out for 40 minutes to obtain denitrified raw oil. (3) After denitrification, the raw oil enters the settling tank D-202 for settling and separation to remove the remaining denitrification tailings; after separation, the oil phase and BLS2000 type low temperature high efficiency adsorbent enter the adsorption tank together, and the mass ratio of adsorbent to raw oil is controlled at 1.0%, the reaction temperature is 120℃, and the adsorption reaction is carried out for 40 minutes. (4) After the adsorption reaction is completed, the raw oil is pumped into the degassing tank and degassed under vacuum for 40 minutes at a temperature of 125℃ and a vacuum degree of 0.08MPa. Then it is pumped into the heat exchanger E-101 for heating and then into the first-stage plate and frame filter (filtration accuracy of 10μm). After filtration for 3 minutes at a temperature of 128℃ and a pressure of 0.4MPa, it enters the buffer tank D-105. Then it is pumped into the second-stage plate and frame filter (filtration accuracy of 4μm). After filtration for 3 minutes at a temperature of 128℃ and a pressure of 0.4MPa, it enters the buffer tank D106 to obtain bright oil. The yield of bright oil is 99.6%.

[0027]

[0028] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications are also within the protection scope of the present invention.

Claims

1. A method for preparing a gloss varnish, characterized in that, Includes the following steps: (1) The deasphalted oil after furfural extraction and ketone-benzene dewaxing enters the raw material buffer tank; (2) The raw oil in the raw material buffer tank is pumped into the heating furnace and then enters the evaporation tower to carry out the light component removal reaction to remove moisture and light components from the raw material; (3) The raw oil after light removal in the evaporation tower is pumped into the electrorefining tank and reacted with the denitrifying agent to remove the alkaline nitrogen from the raw material; (4) After denitrification, the raw oil enters the adsorbent tank and undergoes an adsorption reaction with a low-temperature high-efficiency adsorbent to remove residual naphthenic acid, solvent, water and mechanical impurities from the raw oil. (5) The raw oil mixed with adsorbent enters the degassing tank and filter in sequence for vacuum degassing and plate and frame filtration to remove the adsorbent and obtain bright oil.

2. The method for preparing a gloss varnish according to claim 1, characterized in that, In step (1), the basic nitrogen content of the raw oil in the raw material buffer tank is 100~150ppm, the color is 4~5, and the acid value is 0.01~0.05mgKOH / g.

3. The method for preparing a gloss varnish according to claim 1, characterized in that, In step (2), the temperature of the evaporator is 135~145℃ and the pressure at the top of the tower is -0.09~-0.05MPa.

4. The method for preparing a gloss varnish according to claim 1, characterized in that, In step (3), the denitrifying agent is a WSQ series high-selectivity denitrifying agent, the mass ratio of the denitrifying agent to the raw oil is 0.6%~1.0%, and the denitrification reaction temperature is 85~110℃.

5. The method for preparing a gloss varnish according to claim 1, characterized in that, In step (4), the adsorbent is a porous inorganic mineral composite adsorbent, the mass ratio of the adsorbent to the raw oil is 0.7%~1.2%, and the adsorption reaction temperature is 100~140℃.

6. The method for preparing a gloss varnish according to claim 1, characterized in that, In step (5), the temperature of vacuum degassing is 120~130℃ and the vacuum degree is 0.07~0.08MPa.

7. The low-temperature adsorption process for bright oil according to claim 1, characterized in that, Plate and frame filters include primary filtration and secondary filtration. The filtration accuracy of primary filtration is 5~10μm, and the filtration accuracy of secondary filtration is 2~5 (excluding 5)μm. The temperature of primary filtration is 120~130℃ and the pressure is 0.3~0.5Mpa; the temperature of secondary filtration is 120~130℃ and the pressure is 0.3~0.5Mpa.

8. The method for preparing a gloss varnish according to claim 1, characterized in that, It also includes: the raw oil obtained in step (2) and the raw oil obtained in step (4) exchange heat and cool down before entering the electro-refining tank for denitrification reaction; the raw oil obtained in step (4) and the raw oil obtained in step (2) exchange heat and heat up before entering the degassing tank for vacuum degassing.

9. The method for preparing a gloss varnish according to claim 1, characterized in that, In step (1), the viscosity of the deasphalted oil at 100℃ is 22~24 mm. 2 / s, freezing point 45~50℃, acid value 0.01~0.05mgKOH / g, basic nitrogen content 200~300ppm, residual carbon 1.3%~1.5%, color 4.5~5.5, flash point 260~290℃.

10. A method for preparing a gloss varnish according to claim 1, characterized in that, In step (5), the viscosity of the obtained bright oil at 100℃ is 23~25 mm. 2 / s, freezing point -9~-12℃, acid value 0.01~0.03mgKOH / g, basic nitrogen content 45~75ppm, residual carbon 0.45%~0.5%, color 3.0~3.5, flash point 270~285℃.

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