Simple and efficient waste lubricating oil regeneration method

Abstract

A simple and efficient waste lubricating oil regeneration method specifically adopts the following main specific production procedures: demetallization, dehydration, light hydrocarbon removal, heavy oil removal, dechlorination and hydrofining, and in the regeneration method, an extraction unit is canceled; due to the fact that the extraction unit is mainly used for removing heavy aromatic hydrocarbon components in raw materials, tests find that heavy aromatic hydrocarbon in the raw materials can be removed through hydrogenation dearomatization reaction by selecting a proper hydrogenation catalyst, part of the raw materials can be lost in the extraction process of the extraction unit, and therefore the recovery rate is affected. After the extraction step is omitted, the same dearomatization effect can be achieved through direct hydrofining, and the recovery rate of the base oil is higher; and an extraction unit is omitted, so that the processing cost is greatly reduced.

Description

Technical Field

[0001] The present application belongs to the field of petrochemical technology, and in particular relates to a simple (simple process flow) and efficient (high recovery rate can reach base oil yield ≥ 77%) waste lubricating oil regeneration method. Background Art

[0002] Lubricating oil is widely used in the automotive, machinery, chemical, textile and other industries. Lubricating oil is mainly composed of 80% to 90% base oil and various additives. It has the functions of reducing friction, cooling machinery, sealing machinery, protecting machinery, lubricating, cleaning and rust prevention. The deterioration of lubricating oil is a very complicated process. First, impurities mixed from the outside pollute the lubricating oil, and second, chemical impurities are generated by oxidation and deterioration during the use of lubricating oil. After long-term use, part of the base oil in the lubricating oil is oxidized, degraded and deteriorated, and part of the additives are consumed and deteriorated, gradually forming acidic oxides, colloidal asphalt, etc.

[0003] Under the new environmental protection situation, the development direction of lubricating oil must adapt to the new environmental protection requirements. Waste lubricating oil discharged without treatment will pollute the environment, while most of the components in lubricating oil have not deteriorated and can be recycled. With the increase in the use of lubricating oil, a large amount of waste lubricating oil is produced in my country every year. Waste lubricating oil is a very potential recycling resource. Waste lubricating oil regeneration is not only of great significance to environmental protection, but also can bring rich economic benefits.

[0004] The traditional waste oil regeneration process has its own technical defects, low base oil recovery rate and secondary pollution to the environment during the regeneration process. In recent years, new pollution-free and environmentally friendly waste oil regeneration processes with high lubricant base oil recovery have become the main development direction. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present application provides a simple and efficient waste lubricating oil regeneration method with a simple production process, low production cost and high recovery rate.

[0006] In order to solve the above technical problems, the technical solution adopted in this application is as follows: a simple and efficient waste lubricating oil regeneration method, comprising the following steps:

[0007] (1) Waste lubricating oil is heated and settled in the raw material tank to remove metal impurities;

[0008] (2) After the raw materials are heated and settled, they enter a flash tower where free water is removed;

[0009] (3) After flash evaporation, the material enters a light oil removal tower to remove light oil components;

[0010] (4) The material after the light oil removal tower is heated and then enters the vacuum tower to remove the heavy oil component to obtain distillate oil;

[0011] (5) The distillate oil is heated and then enters a dechlorination reactor for dechlorination, and then is washed with water and flashed to obtain a hydrogenation feedstock;

[0012] (6) The hydrogenation raw material is desiliconized by a silicon trapping agent and then subjected to a hydrogenation refining reaction to remove impurities such as sulfur, nitrogen and aromatic hydrocarbons in the hydrogenation raw material obtained by pretreatment;

[0013] (7) The hydrogenation reaction product can be cut into high-quality base oil products through a distillation system.

[0014] Preferably, the distillate oil content in the raw waste lubricating oil in step (1) is ≥80%, the distillation tail oil content is ≤8%, and the open flash point is ≥170°C.

[0015] Preferably, the temperature of the raw material tank for heating and settling in step (1) is 40-60°C.

[0016] Preferably, the waste lubricating oil is pretreated in steps (1) to (5) to remove impurities such as metal impurities, moisture, light oil, heavy oil, and chlorine in the raw material.

[0017] Preferably, the operating conditions of the flash tower in step (2) are: temperature 100 to 250° C., pressure -0.1 to -0.02 KPa.

[0018] Preferably, the operating conditions of the lightness removal tower in step (3) are: temperature 200 to 300° C., pressure -0.2 to -0.05 MPa.

[0019] Preferably, the operating conditions of the vacuum distillation tower in step (4) are: temperature 300 to 400° C., pressure -0.2 to -0.05 MPa.

[0020] Preferably, the dechlorination temperature in step (5) is 250-350° C., and the dechlorinating agent is an alkaline mixture of potassium alkali (such as potassium hydroxide) and sodium alkali (such as sodium hydroxide) in a weight ratio of 3:7 to 5:5.

[0021] Preferably, the chlorine content in the hydrotreating reaction raw material obtained after raw material pretreatment is less than 2 mg / kg.

[0022] Preferably, the hydrofining part comprises three reactors, the first reactor is filled with a hydrodesulfurization catalyst A, and the second and third reactors are filled with a hydrodearomatization catalyst B.

[0023] Preferably, a silicon scavenger is loaded on the top of the catalyst in the first reactor, and the main components of the loaded silicon scavenger are MoO3 and NiO, in a bird's nest shape; the main function of the silicon scavenger is to remove silicon from the raw material, pre-hydrogenate the hydrogenation raw material, and protect the catalyst.

[0024] Preferably, the metal content in the hydrodesulfurization catalyst A is less than 15%, and the specific surface area is 150-250m 2 / g, pore volume is 0.5-0.8ml / g, bulk density is 0.4-0.8g / ml, infrared acid content is 0.5-0.8mmol / g; the deep hydrodesulfurization catalyst prepared in application number 201711400168.1 is used.

[0025] Preferably, the metal content of the hydrodearomatization catalyst B is less than 12% and the specific surface area is 130 to 280 m 2 / g, the pore volume is 0.4-0.9 ml / g, the water absorption rate is 110-150%, and the ratio of B acid / L acid is 1.6-2.2; the hydrodearomatization catalyst prepared in application No. 202010331191.5 is used.

[0026] Preferably, the hydrofining reaction conditions are: reaction pressure 10-20 MPa, reaction temperature 280-380°C / 260-380°C / 230-320°C, hydrogen-to-oil ratio 500-2000:1, reaction space velocity 0.3-1.2h -1 .

[0027] Preferably, the present application can obtain 150SN base oil, the obtained base oil has a chromaticity (Saybolt) of ≥+30 and a kinematic viscosity (40°C) of 25-35 mm 2 / s, open flash point>200℃, viscosity index≥115, aromatics≤1%, sulfur content≤1mg / kg.

[0028] Advantages and beneficial effects of this application:

[0029] 1. The distillate oil content in the waste lubricating oil selected in the present application is ≥80%, and after raw material pretreatment and hydrofining treatment, the base oil yield obtained is ≥77%; the yield of the base oil processed from the waste lubricating oil is high; this is because the technical solution of the present application eliminates the extraction unit in the specific regeneration method; since the function of the extraction unit is mainly to remove the heavy aromatic components in the raw material, but it has been found through experiments that the heavy aromatics in the raw material can be removed by selecting a suitable hydrogenation catalyst through hydrogenation dearomatization reaction, and part of the raw material will also be lost during the extraction process in the extraction unit, thereby affecting the recovery rate; after eliminating the extraction step, the same dearomatization effect can be achieved by direct hydrofining, and the recovery rate of the base oil is higher; and the extraction unit is omitted, and the processing cost is also greatly reduced.

[0030] 2. The raw material pretreatment part of the present application includes a dechlorination unit, which controls the chlorine content in the raw materials of the hydrofining part within 2 mg / kg, avoids corrosion of the equipment, reduces the impact of hydrofining by-products on the hydrogenation reaction, protects the catalyst, and ensures product quality.

[0031] 3. The present application adopts the following main specific production processes: demetallization - dehydration - removal of light hydrocarbons - removal of heavy oil - dechlorination - hydrorefining, and processes waste lubricating oil as raw material to produce high-quality base oil. The method is safe and environmentally friendly, with a simple process, mild operating conditions, low equipment requirements, low production and processing costs, high yield of target products, and significant economic benefits.

[0032] 4. The 150SN base oil produced in this application has a base oil color (Saybolt) ≥ +30 and a kinematic viscosity (40°C) of 25-35 mm 2 / s, open flash point>200℃, viscosity index≥115, aromatics≤1%, sulfur content≤1mg / kg.

[0033] 5. In the present application, a silicon scavenger is loaded on the upper part of the catalyst in the first reactor. The main components of the silicon scavenger are MoO3 and NiO, and the shape is a bird's nest. The main function of the silicon scavenger is to remove silicon from the raw material and pre-hydrogenate the raw material, which can effectively protect the catalyst, and the amount used is not limited. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The equipment process flow chart of the present application's simple and efficient waste lubricating oil regeneration method.

[0035] As attached Figure 1 Shown: 1. Raw material tank, 2. Intermediate tank, 3. Flash tower, 4. Dehydrogenation tower, 5. Vacuum tower, 6. Dechlorination reactor, 7. Water washing tower, 8. Flash tower, 9. First reactor, 10. Second reactor, 11. Third reactor, 12. Fractionation tower, 13. Fractionation tower. DETAILED DESCRIPTION

[0036] The present application can be further described in detail with reference to the following examples; however, the following examples are merely illustrative, and the present application is not limited to these examples.

[0037] The specific embodiment of the present application adopts the device flow chart of the regeneration method as shown in Figure 1, in which: first, the raw material is stored in the raw material tank 1, then enters the intermediate tank 2, and then enters the flash tower 3, and then enters the light oil removal tower 4 from the flash tower 3 to remove the light oil, and after the light oil removal is completed, it enters the vacuum tower 5, and then enters the dechlorination reactor 6, the water washing tower 7 and the flash tower 8. After the treatment is completed, it enters the first reactor 9, the second reactor 10 and the third reactor 11 for hydrogenation refining reaction, and the product is cut through the fractionation tower 12 and the fractionation tower 13 to finally obtain the hydrogenation refining reaction product; each device in the flow chart of the present application can adopt the conventional device structure in the industry, and the most important invention point of the present application lies in the design of the process of the present application, the setting of corresponding parameters and the use of various materials.

[0038] Example 1

[0039] A method for regenerating waste lubricating oil comprises the following steps:

[0040] 1. Waste lubricating oil (water content 2.8%, distillate oil content 89%, distillation tail oil content 1.6%, open flash point 182°C) is precipitated in raw material tank 1 to remove metal impurities, and then enters intermediate tank 2 after precipitation at 50°C. The raw materials in intermediate tank 2 are heated and enter flash tower 3 (temperature 125°C, pressure -0.02KPa), where water is removed. After flash evaporation, the material enters light removal tower 4 (temperature 260°C, pressure -0.15MPa) to remove light hydrocarbon components. The material after light removal tower 4 is After being heated, the material enters into a vacuum tower 5 (vacuum distillation tower, temperature 350°C, pressure -0.12MPa) to remove heavy oil components, and the obtained distillate oil enters into a dechlorination reactor 6 (320°C, the dechlorination agent is an alkaline mixture of potassium hydroxide and sodium hydroxide in a weight ratio of 3:7). After heat exchange, the material coming out of the dechlorination reactor 6 is washed with water in a water washing tower 7 (65°C), and then enters into a flash tower 8 (temperature 145°C, pressure -0.1KPa) to remove moisture, and the obtained dechlorinated distillate oil is used as a hydrogenation feedstock.

[0041] 2. The dechlorinated distillate oil obtained by the pretreatment in step 1 is used as a raw material, which is mixed with hydrogen after being pressurized by a raw material pump, and enters a first reactor 9 loaded with a silicon scavenger (the main components of the silicon scavenger are MoO3, NiO, and a bird's nest shape; such as the silicon scavenger prepared in Example 2 of Application No. 201911020775.4), a catalyst A (the hydrodearomatization catalyst prepared in Example 1 of Application No. 202010331191.5) and a second reactor 10 and a third reactor 11 loaded with a catalyst B (the hydrodearomatization catalyst prepared in Example 1 of Application No. 202010331191.5), at 15 MPa, 350 / 350 / 260°C (the corresponding temperatures in the first reactor, the second reactor and the third reactor, respectively), a hydrogen-to-oil ratio of 800:1, and a reaction space velocity of 0.8 h -1 . Hydrofining reaction is carried out, and then the product is cut through the fractionation tower 12 and the fractionation tower 13, and finally the Class II base oil is obtained. The properties of the obtained base oil are shown in Table 1. After the waste lubricating oil is subjected to raw material pretreatment and hydrofining treatment, the base oil yield is 85.4%.

[0042] Table 1 Base oil product analysis

[0043]

[0044]

[0045] Example 2

[0046] A method for regenerating waste lubricating oil comprises the following steps:

[0047] 1. Waste lubricating oil (water content 2.1%, distillate oil content 87%, distillation tail oil content 2.4%, open flash point 185°C) is precipitated in raw material tank 1 to remove metal impurities. After precipitation at 45°C, the raw material enters intermediate tank 2. The raw material in intermediate tank 2 is heated and enters flash tower 3 (temperature 120°C, pressure -0.08KPa). Water is removed in flash tower 3. After flash evaporation, the material enters light-removal tower 4 (temperature 255°C, pressure -0.15MPa) to remove light hydrocarbon components. The material after heating enters into a vacuum tower 5 (temperature 355°C, pressure -0.08MPa) to remove heavy oil components, and the obtained distillate oil enters into a dechlorination reactor 6 (300°C, the dechlorination agent is an alkaline mixture of potassium hydroxide and sodium hydroxide in a weight ratio of 5:5). The material coming out of the dechlorination reactor 6 is washed with water through a water washing tower 7 (70°C) after heat exchange, and then enters into a flash tower 8 (temperature 120°C, pressure -0.1MPa) to remove moisture, and the obtained dechlorinated distillate oil is used as a hydrogenation feedstock.

[0048] 2. The dechlorinated distillate oil obtained by pretreatment in step 1 is used as a raw material, pressurized by a raw material pump, mixed with hydrogen, and enters a first reactor 9 loaded with a silicon scavenger (such as the silicon scavenger prepared in Example 3 of Application No. 201911020775.4) and a catalyst A (using the hydrodearomatization catalyst prepared in Example 1 of Application No. 202010331191.5) and a second reactor 10 and a third reactor 11 loaded with a catalyst B (using the hydrodearomatization catalyst prepared in Example 1 of Application No. 202010331191.5), at 16 MPa, 330 / 330 / 260°C, a hydrogen-to-oil ratio of 1500:1, and a reaction space velocity of 1.0 h -1 The waste lubricating oil is subjected to a hydrofining reaction under the condition of 100 ℃ and 150 ℃, and then the product is cut through the fractionation tower 12 and the fractionation tower 13 to obtain the Class II base oil. The properties of the obtained base oil are shown in Table 2. After the waste lubricating oil is subjected to the raw material pretreatment and the hydrofining treatment, the base oil yield is 83.8%.

[0049] Table 2 Base oil product analysis

[0050]

[0051] Through the above examples, the 150SN base oil produced in this application has a chromaticity (Saybolt) ≥ +30, a kinematic viscosity (40°C) of 25-35 mm 2 / s, open flash point>200℃, viscosity index≥115, aromatics≤1%, sulfur content≤1mg / kg; distillate oil content in waste lubricating oil≥80%, and after raw material pretreatment and hydrofining treatment, the base oil yield obtained is ≥77%.

Claims

1. A simple and efficient waste lubricating oil regeneration method, characterized in that: The following steps are involved: (1) Waste lubricating oil is heated and settled in the raw material tank to remove metal impurities; (2) After the raw materials are heated and settled, they enter a flash tower where free water is removed; (3) After flash evaporation, the material enters a light oil removal tower to remove light oil components; (4) The material after the light oil removal tower is heated and then enters the vacuum tower to remove the heavy oil component to obtain distillate oil; (5) The distillate oil is heated and then enters a dechlorination reactor for dechlorination, and then is washed with water and flashed to obtain a hydrogenation feedstock; (6) The hydrogenation raw material is desiliconized by a silicon trapping agent and then subjected to a hydrogenation refining reaction to remove impurities such as sulfur, nitrogen and aromatic hydrocarbons in the hydrogenation raw material obtained by pretreatment; (7) The hydrogenation reaction product can be cut into high-quality base oil products through a distillation system.

2. The simple and efficient waste lubricating oil regeneration method according to claim 1 is characterized in that: The distillate oil content in the raw waste lubricating oil in step (1) is ≥80%, the distillation tail oil content is ≤8%, and the open flash point is ≥170°C; the heating and settling temperature of the raw material tank in step (1) is 40-60°C.

3. The waste lubricating oil regeneration method according to claim 1, characterized in that: The operating conditions of the flash tower in step (2) are: temperature 100-250° C., pressure -0.1-0.02 KPa.

4. The waste lubricating oil regeneration method according to claim 1, characterized in that: The operating conditions of the lightness removal tower in step (3) are: temperature 200-300° C., pressure -0.2-0.05 MPa.

5. The waste lubricating oil regeneration method according to claim 1, characterized in that: The operating conditions of the vacuum distillation tower in step (4) are: temperature 300-400° C., pressure -0.2-0.05 MPa.

6. The waste lubricating oil regeneration method according to claim 1, characterized in that: In step (5), the dechlorination temperature is 250-350° C., and the dechlorinating agent is an alkaline mixture of potassium alkali and sodium alkali in a weight ratio of 3:7-5:

5.

7. The waste lubricating oil regeneration method according to claim 1, characterized in that: The chlorine content in the raw material for hydrogenation refining reaction obtained after raw material pretreatment is less than 2 mg / kg.

8. The waste lubricating oil regeneration method according to claim 1, characterized in that: The hydrorefining part includes three reactors. The first reactor is filled with hydrodesulfurization catalyst A, and the second and third reactors are filled with hydrodearomatization catalyst B. The upper part of the catalyst in the first reactor is filled with silicon scavenger, and the main components of the silicon scavenger are MoO3 and NiO, and the shape of a bird's nest.

9. The waste lubricating oil regeneration method according to claim 1, characterized in that: The metal content of hydrodesulfurization catalyst A is less than 15%, and the specific surface area is 150-250m 2 / g, pore volume is 0.5-0.8ml / g, bulk density is 0.4-0.8g / ml, infrared acid content is 0.5-0.8mmol / g; the metal content in the hydrodearomatization catalyst B is less than 12%, and the specific surface area is 130-280m 2 / g, pore volume is 0.4~0.9ml / g, water absorption is 110~150%, and the ratio of B acid / L acid is 1.6~2.

2.

10. The waste lubricating oil regeneration method according to claim 1, characterized in that: Hydrogenation refining reaction conditions: reaction pressure 10-20MPa, reaction temperature 280-380℃ / 260-380℃ / 230-320℃, hydrogen-oil ratio 500-2000:1, reaction space velocity 0.3-1.2h -1 The distillate oil content in the selected waste lubricating oil is ≥80%, and after raw material pretreatment and hydrofining treatment, the base oil yield obtained is ≥77%.

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