A process for the production of deasphalted oil from solvent deasphalting

Abstract

The application discloses a method for producing deasphalted oil by solvent deasphalting. The method comprises the following steps: taking petroleum residual oil as raw material, and using an alkane solvent with a carrying agent added as an extractant to extract the petroleum residual oil, so that the obtained extract liquid is deasphalted oil. When the method is used for producing deasphalted oil, the product yield can be improved under the premise of ensuring the quality of the product deasphalted oil.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of solvent deasphalting, and particularly relates to a method for producing deasphalted oil by solvent deasphalting. BACKGROUND

[0002] The solvent deasphalting process is an important link in the production of catalytic cracking raw materials and lubricating oil processing, and is also an indispensable key process for producing various high-quality petroleum wax products such as microcrystalline wax and vaseline. The deoiled asphalt produced by solvent deasphalting is an important raw material for producing road asphalt and construction asphalt, so the solvent deasphalting device has always been one of the important processing units of various oil refining enterprises.

[0003] The solvent deasphalting technology is a pure physical extraction process without chemical change, and does not damage the molecular structure of the raw material. The solvent deasphalting is a process engineering that separates residual carbon, deasphalted oil with low contents of heavy metals, sulfur and nitrogen, and deoiled asphalt with less oil content from residual oil by using small molecular hydrocarbons such as propane and butane as extraction solvents. The solvent deasphalting device uses the solubility of small molecular hydrocarbons to residual oil as the theoretical basis. Within a certain range, these small molecular hydrocarbons have strong solubility to alkanes, naphthenes and single-ring aromatics, weak solubility to multi-ring aromatics and condensed ring aromatics, and almost no solubility to asphaltene, so that a solvent deasphalted oil (DAO) with low contents of residual carbon, heavy metals, sulfur and nitrogen can be obtained. CN1330697A discloses a material filtration method combining solvent deasphalting and gasification. The method includes contacting a hydrocarbon liquid containing asphaltene with a solvent to generate a mixture. The solvent is typically an alkane such as propane to pentane.

[0004] However, due to the high selectivity of the extraction solvent, the DAO yield is low under the premise of ensuring the quality of DAO. Under the premise of ensuring the quality of DAO, it is an urgent problem to be solved to improve the DAO yield of solvent deasphalting. SUMMARY

[0005] In view of the problems existing in the prior art, the application provides a method for producing deasphalted oil by solvent deasphalting. When the method is used to produce deasphalted oil, the product yield can be improved under the premise of ensuring the quality of the product deasphalted oil.

[0006] The application provides a method for producing deasphalted oil by solvent deasphalting. The method comprises: using petroleum residual oil as a raw material, using an alkane solvent with a carrying agent added as an extractant to extract the petroleum residual oil, and obtaining an extract liquid, which is deasphalted oil.

[0007] According to the present application, the petroleum residue is the residue obtained by atmospheric or vacuum distillation of crude oil. The petroleum residue has the following properties: asphaltene content of 2wt% to 8wt%; initial boiling point ≥ 530°C, preferably 530 to 560°C; softening point 45 to 85°C; penetration at 25°C of 200 to 300, 1 / 10 mm; elongation (10°C) ≥ 150 cm, preferably 150 to 180 cm; preferably, the petroleum residue is a vacuum residue, preferably selected from at least one of the group consisting of light Arabian vacuum residue, heavy Arabian vacuum residue, Oman vacuum residue, Lula vacuum residue, Chunfeng vacuum residue.

[0008] According to the present application, the alkane solvent is an alkane having 3 to 6 carbon atoms. Preferably, the alkane solvent comprises at least one of propane, butane, pentane, hexane, preferably propane.

[0009] According to the present application, the carrying agent comprises at least one of di(2-ethylhexyl)phosphate, tricresyl phosphate, tri-n-butyl phosphate, 2-ethylhexyl 2-ethylhexyl phosphate, triethylamine, tri-octylamine, preferably tri-octylamine.

[0010] According to the present application, the preparation method of the extractant is to mix the alkane solvent and the carrying agent uniformly.

[0011] According to the present application, the amount of the carrying agent added is 0.5wt% to 5.0wt% of the mass of the petroleum residue. As a non-limiting example, the amount of the carrying agent added can be 1wt%, 2wt%, 3wt%, 4wt% of the mass of the petroleum residue.

[0012] According to the present application, the mass ratio of the alkane solvent to the petroleum residue (solvent to oil ratio) is 3:1 to 5:1.

[0013] According to the present application, the extraction process is preferably carried out in an extraction column. The operating pressure of the extraction is 4.2 to 8.0 MPa. The extraction temperature is 50 to 100°C. Preferably, the extraction column is operated in a constant pressure and decreasing temperature mode. The temperature ranges in the extraction column are: 70 to 100°C at the top, 60 to 90°C in the middle, and 50 to 75°C at the bottom. Preferably, the temperature in the extraction column is: at least 8 to 20°C higher at the top than in the middle; at least 10 to 20°C higher in the middle than at the bottom.

[0014] According to the present application, preferably, the raw oil can be preheated before entering the extraction column. The raw oil is preheated to 100 to 130°C.

[0015] According to the present application, the operation process of the extraction is as follows: the extractant flows upward from the bottom of the tower along with the solvent, the petroleum residue flows downward from the middle of the tower, the petroleum residue and the extractant are countercurrently contacted in the tower, the residue is discharged from the bottom of the tower, and the extraction liquid is discharged from the upper part of the tower; the extraction liquid is the target product deasphalted oil.

[0016] Compared with the prior art, the present application has the following beneficial effects:

[0017] In the method for producing deasphalted oil by solvent deasphalting according to the present application, the selectivity of the solvent and the solubility of the solute are increased by adding a specific content of a carrying agent into the extractant and using the interaction force between the molecules of the carrying agent and the solute, so that the yield of the deasphalted oil is increased under the premise that the quality of the deasphalted oil product is unchanged. The extraction process of the deasphalted oil is changed by adding the carrying agent under the premise that the inner members of the extraction tower are not modified. The yield of the deasphalted oil obtained by the above method is increased by 7-22 percentage points compared with the method for producing deasphalted oil without adding the carrying agent under the premise that the quality of the deasphalted oil product is unchanged (residual carbon <1.8%). The method according to the present application increases the yield of the product under the premise that the quality of the deasphalted oil product is unchanged, increases the benefits of the enterprise, and achieves remarkable technical effects. DETAILED DESCRIPTION

[0018] The present application will be further described in detail below in combination with examples, but the present application is not limited to these examples.

[0019] In the present application, the petroleum residue is used as the raw oil, and the raw oil is Oman vacuum residue. The initial boiling point of the raw oil is 530℃, the softening point is 48.1℃, the penetration (25℃) is 280, the ductility (10℃) is 152 cm, and the asphaltene content is 3.6wt%.

[0020] In the present application, the carbon residue value is tested by the method for testing carbon residue of petroleum products in GB / T17144-1997.

[0021] In the present application, the yield of the deasphalted oil is tested by the weight method.

[0022] In the present application, % is mass percentage unless otherwise specified.

[0023] Example 1

[0024] Take 1000g of Oman vacuum residue, preheated to 130℃ into the solvent deasphalting device (extraction column). Propane as solvent, solvent to oil ratio of 3:1. Bis (2-ethylhexyl) phosphate as carrying agent, the amount of 0.5% of the mass of the raw material oil. Extraction conditions: operating pressure of 4.5 MPa, 100℃ at the top of the column, 90℃ in the middle of the column, 75℃ at the bottom of the column. Under the condition of constant pressure cooling operation, fractionation, 5% of the distillate as a fractionation point, a total of 12 fractionation points. The measurement of the fraction residual carbon value, product deasphalted oil 30wt% yield, the fraction residual carbon value is 1.73wt%, meet the deasphalted oil residual carbon <1.8wt% index.

[0025] Example 2

[0026] Take 1000g of Oman vacuum residue, preheated to 130℃ into the solvent deasphalting device (extraction column). Propane as solvent, solvent to oil ratio of 3:1. Bis (2-ethylhexyl) phosphate as carrying agent, the amount of 3% of the mass of the raw material oil. Extraction conditions: operating pressure of 4.5 MPa, 100℃ at the top of the column, 90℃ in the middle of the column, 75℃ at the bottom of the column. Under the condition of constant pressure cooling operation, fractionation, 5% of the distillate as a fractionation point, a total of 12 fractionation points. The measurement of the fraction residual carbon value, product deasphalted oil 35wt% yield, the fraction residual carbon value is 1.79wt%, meet the deasphalted oil residual carbon <1.8wt% index.

[0027] Example 3

[0028] Take 1000g of Oman vacuum residue, preheated to 130℃ into the solvent deasphalting device (extraction column). Propane as solvent, solvent to oil ratio of 3:1. Bis (2-ethylhexyl) phosphate as carrying agent, the amount of 5% of the mass of the raw material oil. Extraction conditions: operating pressure of 4.5 MPa, 100℃ at the top of the column, 90℃ in the middle of the column, 75℃ at the bottom of the column. Under the condition of constant pressure cooling operation, fractionation, 5% of the distillate as a fractionation point, a total of 12 fractionation points. The measurement of the fraction residual carbon value, product deasphalted oil 35wt% yield, the fraction residual carbon value is 1.76wt%, meet the deasphalted oil residual carbon <1.8wt% index.

[0029] Example 4

[0030] Take 1000g of Oman vacuum residue, preheated to 130°C into the solvent deasphalting device (extraction column). Propane as solvent, solvent oil ratio is 3:1. Tertiary trioctylamine as carrying agent, the amount of 0.5% of the mass of the raw material oil. Extraction conditions: operating pressure of 4.5 MPa, 100 ℃ at the top of the column, 90 ℃ in the middle of the column, 75 ℃ at the bottom of the column. Under the condition of constant pressure cooling operation, 5% of the distillate is a fractionation point, a total of 12 fractionation points are pulled out. The residual carbon value of the fraction is measured, and the product deasphalted oil has a yield of 38wt%, the residual carbon value of the fraction is 1.71wt%, which meets the index of deasphalted oil residual carbon <1.8wt%.

[0031] Example 5

[0032] Take 1000g of Oman vacuum residue, preheated to 130°C into the solvent deasphalting device (extraction column). Propane as solvent, solvent oil ratio is 3:1. Tertiary trioctylamine as carrying agent, the amount of 0.5% of the mass of the raw material oil. Extraction conditions: operating pressure of 4.5 MPa, 100 ℃ at the top of the column, 90 ℃ in the middle of the column, 75 ℃ at the bottom of the column. Under the condition of constant pressure cooling operation, 5% of the distillate is a fractionation point, a total of 12 fractionation points are pulled out. The residual carbon value of the fraction is measured, and the product deasphalted oil has a yield of 38wt%, the residual carbon value of the fraction is 1.71wt%, which meets the index of deasphalted oil residual carbon <1.8wt%.

[0033] Comparative Example 1

[0034] The same as Example 1, the difference is that no carrying agent is added.

[0035] Take 1000g of Oman vacuum residue, preheated to 130°C into the solvent deasphalting device (extraction column). Propane as solvent, solvent oil ratio is 3:1. Extraction conditions: operating pressure of 4.5 MPa, 100 ℃ at the top of the column, 90 ℃ in the middle of the column, 75 ℃ at the bottom of the column. Under the condition of constant pressure cooling operation, 5% of the distillate is a fractionation point, a total of 11 fractionation points are pulled out. The residual carbon value of the fraction is measured, and the product deasphalted oil has a yield of 23wt%, the residual carbon value of the fraction is 1.77wt%, which meets the index of deasphalted oil residual carbon <1.8wt%. Under the condition that the product quality meets the requirements, the product yield is low.

[0036] Comparative Example 2

[0037] The same as Example 1, the difference is that the carrying agent is nonylphenol polyoxyethylene ether NP-10.

[0038] Take 1000g Oman vacuum residue, preheated to 130℃ into the solvent deasphalting device (extraction column). Propane as solvent, solvent to oil ratio is 3:1. Nonyl phenol polyoxyethylene ether NP-10 as carrying agent, the amount of 0.5% of the mass of the raw oil. The extraction conditions are: operating pressure is 4.5MPa, 100℃ at the top of the tower, 90℃ in the tower, 75℃ at the bottom of the tower. Under the condition of constant pressure cooling operation, fractionation, distillate 5% as a fractionation point, a total of 11 fractionation points. The fraction residual carbon value is measured, the product deasphalted oil 25wt% yield, the fraction residual carbon value is 1.76wt%, meet the deasphalted oil residual carbon <1.8wt% index. Under the condition of product quality to meet the requirements, the product yield is low.

[0039] The above detailed the specific embodiments of the present application, however, the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including various technical features being combined in any other suitable manner, and these simple modifications and combinations should also be considered as disclosed by the present application, and all fall within the protection scope of the present application.

Claims

1. A method of solvent deasphalting to produce deasphalted oil, characterized by, The method comprises: using petroleum residual oil as raw oil, using an alkane solvent with a carrying agent added as an extractant to extract the petroleum residual oil, and obtaining an extract liquid, which is deasphalted oil; The carrying agent comprises at least one of di(2-ethylhexyl) phosphate, 2-ethylhexyl 2-ethylhexyl phosphate, and trioctylamine. The carrying agent is added in an amount of 0.5wt%-5.0wt% of the mass of the petroleum residual oil. The mass ratio of the alkane solvent to the petroleum residual oil is 3:1-5:

1.

2. The method of claim 1, wherein, The carrying agent is trioctylamine.

3. The method of claim 1, wherein, The alkane solvent is an alkane with 3-6 carbon atoms.

4. The method of claim 3, wherein, The alkane solvent comprises at least one of propane, butane, pentane, and hexane.

5. The method of claim 3, wherein, The alkane solvent is propane.

6. The method of claim 1, wherein, The extraction process is performed in an extraction tower.

7. The method of claim 6, wherein, The operation pressure of the extraction is 4.2-8.0MPa, and the extraction temperature is 50-100℃.

8. The method of claim 6, wherein, The extraction tower is operated in a constant-pressure and temperature-decreasing mode, and the temperature ranges of the extraction tower are 70-100℃ at the top, 60-90℃ in the middle, and 50-75℃ at the bottom.

9. The method of claim 1 or 6, wherein, The raw oil is preheated before entering the extraction tower, and the raw oil is preheated to 100-130℃.

10. The method of claim 1 or 6, wherein, The extractant flows upwards in the tower after entering the tower from the bottom, the petroleum residual oil flows downwards in the tower after entering the tower from the middle, the petroleum residual oil and the extractant are countercurrently contacted in the tower, residues are discharged from the bottom of the tower, and the extract liquid flows out from the upper part of the tower; the extract liquid is the target product, deasphalted oil.

11. The method of claim 1 wherein, The petroleum residual oil has the following properties: an asphaltene content of 2wt%-8wt%, an initial boiling point of ≥530℃, a softening point of 45-85℃, a penetration of 1 / 10mm of 200-300 at 25℃, and an elongation of ≥150cm at 10℃.

12. The method of claim 11, wherein, The petroleum residual oil has the following properties: an initial boiling point of 530-560℃, and an elongation of 150-180cm at 10℃.

13. The method of claim 1 wherein, The petroleum residual oil is vacuum residual oil.

14. The method of claim 13, wherein, The petroleum residual oil is at least one selected from the group consisting of vacuum residual oil of Shale Light, vacuum residual oil of Shale Heavy, vacuum residual oil of Oman, vacuum residual oil of Lula, and vacuum residual oil of Chunfeng.