Method for preparing deasphalted oil through solvent deasphalting

Abstract

The invention discloses a method for preparing deasphalted oil through solvent deasphalting. The method comprises the following steps: extracting petroleum residual oil serving as raw material oil by using an alkane solvent added with a carrying agent as an extracting agent to obtain extract liquor, namely deasphalted oil; particularly, the petroleum residual oil contains a carrying agent; the carrying agent in the extraction agent and the carrying agent in the raw oil are respectively and independently selected from at least one of isooctyl phosphate, tri (4-nonylphenyl) phosphite, tri-p-tolyl phosphate, tri (2, 2, 3, 3-tetrafluoropropyl) phosphate, 2, 2, 2-trifluoroethanol and 2-propylaniline. When the method is used for producing the deasphalted oil, the product quality can be improved on the premise of ensuring the yield of the deasphalted oil.

Description

Technical Field

[0001] The present invention belongs to the field of solvent deasphalting, and particularly relates to a method for preparing deasphalted oil by solvent deasphalting. Background Art

[0002] The solvent deasphalting process is an important link in the production of catalytic cracking feedstock and the lubricating oil processing process, and is also an essential key process for the production of various high-quality petroleum wax products such as microcrystalline wax and vaseline. The by-product deoiled asphalt produced by solvent deasphalting is an important raw material for the production of road asphalt and building asphalt. Therefore, the solvent deasphalting unit plays an important role in the transformation of the refining structure and the process of "oil conversion and oil conversion to specialty products".

[0003] The solvent deasphalting technology is a petrochemical refining process that separates substances from vacuum residue by extraction. Generally, light hydrocarbons such as propane, butane, and pentane are used as solvents. At a certain temperature and pressure, due to the different solubility of the solvent in different components of the VR, deasphalted oil (DAO) rich in saturated hydrocarbons is separated from the VR, and at the same time, deoiled asphalt (DOA) rich in gum and asphaltene is obtained. Using this property, a solvent deasphalting oil DAO with a lower carbon residue value, heavy metal, sulfur, and nitrogen content 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 form a mixture. The solvent is typically an alkane such as propane to pentane.

[0004] However, due to the mutual restriction problem between the yield and quality of the extracted product deasphalted oil, it has always hindered the application and development of the solvent deasphalting technology. Therefore, how to solve the mutual restriction problem between the yield and quality of the extracted product deasphalted oil is an urgent problem to be solved. Summary of the Invention

[0005] In view of the problems existing in the prior art, the present invention provides a method for preparing deasphalted oil by solvent deasphalting. When used for producing deasphalted oil, this method can improve the product quality on the premise of ensuring the yield of the product deasphalted oil. Starting from supercritical solvent deasphalting, the present invention aims to improve the quality of solvent deasphalted DAO on the premise of ensuring the DAO yield, providing a new development direction for the development and application of the solvent deasphalting technology.

[0006] The present invention provides a method for preparing deasphalted oil by solvent deasphalting. The method includes: using petroleum residue as the raw material oil, and using an alkane solvent added with a carrier as the extractant to extract the petroleum residue, and the obtained extract is the deasphalted oil; preferably, the petroleum residue contains the carrier.

[0007] The carrier in the extractant and the carrier in the feedstock oil are each independently selected from at least one of isooctyl phosphate, tris(4-nonylphenyl) phosphite, triphenyl phosphate, tris(2,2,3,3-tetrafluoropropyl) phosphate, 2,2,2-trifluoroethanol, and 2-propylaniline, preferably at least one of isooctyl phosphate and 2,2,2-trifluoroethanol.

[0008] According to the present invention, the petroleum resid is the residue obtained by atmospheric or vacuum distillation of crude oil. The properties of the petroleum resid are as follows: the asphaltene content is 2 wt% to 10 wt%; the 10% distillation point ≥ 500 °C, preferably 500 to 520 °C; the softening point is 25 to 45 °C.

[0009] According to the present invention, preferably, the petroleum resid is vacuum resid, preferably at least one of Shaqing vacuum resid, Shazhong vacuum resid, Oman vacuum resid, Urals vacuum resid, and Saturno vacuum resid.

[0010] According to the present invention, the petroleum resid containing a carrier is obtained by uniformly mixing the petroleum resid and the carrier. Further, the addition amount of the carrier in the feedstock oil accounts for 0.5 wt% to 5.0 wt% of the mass of the petroleum resid. As a non-limiting example, the proportion of the addition amount of the carrier to the mass of the petroleum resid can be 1 wt%, 2 wt%, 3 wt%, 4 wt%.

[0011] According to the present invention, the alkane solvent is an alkane having 3 to 6 carbon atoms. Preferably, the alkane solvent includes at least one of propane, butane, pentane, and hexane, preferably propane.

[0012] According to the present invention, the mass ratio of the addition amount of the carrier in the extractant to the mass of the petroleum resid is 0.5 wt% to 5.0 wt%. As a non-limiting example, the mass ratio of the addition amount of the carrier in the extractant to the mass of the petroleum resid is 1 wt%, 2 wt%, 3 wt%, 4 wt%.

[0013] According to the present invention, the method for preparing the extractant is to uniformly mix the alkane solvent and the carrier.

[0014] According to the present invention, the mass ratio of the alkane solvent to the petroleum resid (solvent-to-oil ratio) is 3:1 to 8:1.

[0015] According to the present invention, the extraction process is preferably carried out in an extraction column. The operating pressure of the extraction is 4.0 to 8.0 MPa. The extraction temperature is 50 to 190 °C. Preferably, a constant pressure and temperature reduction operation mode is adopted in the extraction column. The temperature ranges at different parts of the extraction column are as follows: 70 to 190 °C at the top of the column, 60 to 180 °C in the middle of the column, and 50 to 170 °C at the bottom of the column. Preferably, it is 100 to 140 °C at the top of the column, 90 to 130 °C in the middle of the column, and 80 to 120 °C at the bottom of the column. More preferably, the temperature at different parts of the extraction column: the temperature at the top of the column is at least 10 to 20 °C higher than that in the middle of the column; the temperature in the middle of the column is at least 10 to 20 °C higher than that at the bottom of the column.

[0016] According to the present invention, preferably, the feedstock oil can be preheated before entering the extraction column. The feedstock oil is preheated to 100 to 150 °C.

[0017] According to the present invention, the operating process of the extraction is as follows: the extractant enters the column from the bottom along with the solvent and flows upward, the petroleum residue enters the column from the middle of the column and flows downward, the petroleum residue and the extractant are in countercurrent contact in the column, the residue is discharged from the bottom of the column, and the extract is discharged from the upper part of the column; the extract is the target product deasphalted oil.

[0018] Compared with the prior art, the beneficial effects of the present invention mainly include:

[0019] In the method for producing deasphalted oil by solvent deasphalting according to the present invention, by adding a carrier with a specific content to the extractant, and utilizing the interaction force formed between the carrier molecules and the solute, the selectivity of the solvent and the solubility of the solute are increased, so as to improve the product quality on the premise of ensuring the yield of the deasphalted oil product.

[0020] Preferably, in the method of the present invention, a carrier with a specific content is added to the vacuum residue, and hydrogen bonds are formed between the carrier and the asphaltene molecules or aggregates in the vacuum residue, and acid-base, dipole-dipole and other interactions occur, thereby enhancing the aggregation of asphaltenes. By adding the carrier to both the solvent and the feedstock oil and the combined action of the two, the quality of the deasphalted oil is improved on the premise that the yield of the deasphalted oil product remains unchanged, and remarkable technical effects are achieved. Detailed implementation mode

[0021] The present invention will be further described in detail below in conjunction with embodiments, but the present invention is not limited to these embodiments.

[0022] In the present invention, the petroleum residue used in each example is vacuum residue, and its properties are as follows: the 10% distillation point temperature is 520 °C, the softening point is 38 °C, and the asphaltene content is 7.21 wt%.

[0023] In the present invention, the carbon residue value is tested by the test method of GB / T17144-1997 Determination of carbon residue of petroleum products.

[0024] In the present invention, the deasphalted oil yield is measured by the gravimetric method.

[0025] In the present invention, % is the mass percentage unless otherwise specified.

[0026] Example 1

[0027] An intermittent supercritical solvent deasphalting extraction device was used. Petroleum residue was taken, and then the entrainer triphenyl phosphate was slowly and evenly added. The addition amount of the entrainer in the feed oil accounted for 0.5 wt% of the petroleum residue. The feed oil containing the entrainer was preheated to 105 °C and then introduced into the solvent deasphalting device (extraction tower). Propane was used as the solvent, and the solvent / oil ratio was 5:1. 2,2,2-Trifluoroethanol was used as the solvent entrainer, and the addition amount of the entrainer in the solvent was 0.5 wt% based on the mass of the petroleum residue. The extraction conditions were: the operating pressure was 4.2 MPa, the top of the tower was 115 °C, the middle of the tower was 105 °C, and the bottom of the tower was 95 °C. Fractionation was carried out under the condition of constant pressure and temperature reduction. 5% distillate was taken as a fractionation point, and a total of 6 fractionation points were withdrawn. The carbon residue values of each narrow fraction and cumulative fraction were measured. At a deasphalted oil yield of 21 wt%, the carbon residue value of the fraction was 1.44 wt%.

[0028] Example 2

[0029] An intermittent supercritical solvent deasphalting extraction device was used. Petroleum residue was taken, and then the entrainer triphenyl phosphate was slowly and evenly added. The addition amount of the entrainer in the feed oil accounted for 5 wt% of the petroleum residue. The feed oil containing the entrainer was preheated to 105 °C and then introduced into the solvent deasphalting device (extraction tower). Propane was used as the solvent, and the solvent / oil ratio was 5:1. 2,2,2-Trifluoroethanol was used as the solvent entrainer, and the addition amount of the entrainer in the solvent was 3 wt% based on the mass of the petroleum residue. The extraction conditions were: the operating pressure was 4.2 MPa, the top of the tower was 115 °C, the middle of the tower was 105 °C, and the bottom of the tower was 95 °C. Fractionation was carried out under the condition of constant pressure and temperature reduction. 5% distillate was taken as a fractionation point, and a total of 6 fractionation points were withdrawn. The carbon residue values of each narrow fraction and cumulative fraction were measured. At a deasphalted oil yield of 21 wt%, the carbon residue value of the fraction was 1.08 wt%.

[0030] Example 3

[0031] An intermittent supercritical solvent deasphalting extraction unit was used. Petroleum resid was taken, and then the entrainer triphenyl phosphate was slowly and evenly added. The addition amount of the entrainer in the feedstock oil accounted for 0.5 wt% of the petroleum resid. The feedstock oil containing the entrainer was preheated to 105 °C and then introduced into the solvent deasphalting unit (extraction column). Propane was used as the solvent, and the solvent / oil ratio was 5:1. 2,2,2-trifluoroethanol was used as the solvent entrainer, and the addition amount of the entrainer in the solvent was 5 wt% based on the mass of the petroleum resid. The extraction conditions were as follows: the operating pressure was 4.2 MPa, the top of the column was 115 °C, the middle of the column was 105 °C, and the bottom of the column was 95 °C. Fractionation was carried out under the condition of constant pressure and temperature reduction. 5% distillate was taken as one fractionation point, and a total of 6 fractionation points were withdrawn. The carbon residue values of each narrow fraction and cumulative fraction were measured. At a yield of 21 wt% of the deasphalted oil product, the carbon residue value of the fraction was 1.17 wt%.

[0032] Example 4

[0033] An intermittent supercritical solvent deasphalting extraction unit was used. Petroleum resid was taken, and the entrainer isooctyl phosphate was slowly and evenly added. The addition amount of the entrainer in the feedstock oil accounted for 0.5 wt% of the petroleum resid. The feedstock oil containing the entrainer was preheated to 105 °C and then introduced into the solvent deasphalting unit (extraction column). Propane was used as the solvent, and the solvent / oil ratio was 5:1. 2-propylaniline was used as the entrainer, and the addition amount of the entrainer in the solvent was 0.5 wt% based on the mass of the petroleum resid. The extraction conditions were as follows: the operating pressure was 4.2 MPa, the top of the column was 115 °C, the middle of the column was 105 °C, and the bottom of the column was 95 °C. Fractionation was carried out under the condition of constant pressure and temperature reduction. 5% distillate was taken as one fractionation point, and a total of 6 fractionation points were withdrawn. The carbon residue values of each narrow fraction and cumulative fraction were measured. At a yield of 21 wt% of the deasphalted oil product, the carbon residue value of the fraction was 1.61 wt%.

[0034] Example 5

[0035] An intermittent supercritical solvent deasphalting extraction unit was used. Petroleum resid was taken, and the entrainer isooctyl phosphate was slowly and evenly added. The addition amount of the entrainer in the feedstock oil accounted for 0.5 wt% of the petroleum resid. The feedstock oil containing the entrainer was preheated to 105 °C and then introduced into the solvent deasphalting unit (extraction column). Propane was used as the solvent, and the solvent / oil ratio was 5:1. 2-propylaniline was used as the entrainer, and the addition amount of the entrainer in the solvent was 3 wt% based on the mass of the petroleum resid. The extraction conditions were as follows: the operating pressure was 4.2 MPa, the top of the column was 115 °C, the middle of the column was 105 °C, and the bottom of the column was 95 °C. Fractionation was carried out under the condition of constant pressure and temperature reduction. 5% distillate was taken as one fractionation point, and a total of 6 fractionation points were withdrawn. The carbon residue values of each narrow fraction and cumulative fraction were measured. At a yield of 21 wt% of the deasphalted oil product, the carbon residue value of the fraction was 1.34 wt%.

[0036] Example 6

[0037] Same as Example 1, except that no carrier is added to the feedstock oil.

[0038] An intermittent supercritical solvent deasphalting extraction unit is used. Take petroleum resid, preheat it to 105 °C, and then introduce it into the solvent deasphalting unit (extraction column). Propane is used as the solvent, and the solvent-to-oil ratio is 5:1. 2,2,2-Trifluoroethanol is used as the solvent carrier, and the addition amount of the carrier in the solvent is 0.5 wt% based on the mass of the petroleum resid. The extraction conditions are as follows: the operating pressure is 4.2 MPa, the top of the column is 115 °C, the middle of the column is 105 °C, and the bottom of the column is 95 °C. Fractionation is carried out under the condition of constant pressure and temperature reduction. 5% distillate is taken as one fractionation point, and a total of 6 fractionation points are withdrawn. The carbon residue values of each narrow fraction and cumulative fraction are measured. At a yield of 21 wt% of the deasphalted oil product, the carbon residue value of the fraction is 1.71%.

[0039] Comparative Example 1

[0040] Same as Example 1, except that no carrier is added to both the extractant and the feedstock oil.

[0041] An intermittent supercritical solvent deasphalting extraction unit is used. Take petroleum resid, preheat it to 105 °C and enter the solvent deasphalting unit (extraction column). Propane is used as the solvent, and the solvent-to-oil ratio is 5:1. The extraction conditions are as follows: the operating pressure is 4.2 MPa, the top of the column is 115 °C, the middle of the column is 105 °C, and the bottom of the column is 95 °C. Fractionation is carried out under the condition of constant pressure and temperature reduction. 5% distillate is taken as one fractionation point, and a total of 6 fractionation points are withdrawn. The carbon residue values of each narrow fraction and cumulative fraction are measured. At a yield of 21 wt% of the deasphalted oil product, the carbon residue value of the fraction is 1.8 wt%.

[0042] Comparative Example 2

[0043] Same as Example 1, except that no carrier is added to the feedstock oil. The carrier added to the extractant is nonylphenol polyoxyethylene ether NP-10.

[0044] An intermittent supercritical solvent deasphalting extraction unit is used. Take petroleum resid, preheat it to 105 °C and enter the solvent deasphalting unit (extraction column). Propane is used as the solvent, and the solvent-to-oil ratio is 5:1. Nonylphenol polyoxyethylene ether NP-10 is the carrier added to the extractant. The addition amount of the carrier added to the extractant is 0.5 wt% based on the mass of the petroleum resid. The extraction conditions are as follows: the operating pressure is 4.2 MPa, the top of the column is 115 °C, the middle of the column is 105 °C, and the bottom of the column is 95 °C. Fractionation is carried out under the condition of constant pressure and temperature reduction. 5% distillate is taken as one fractionation point, and a total of 6 fractionation points are withdrawn. The carbon residue values of each narrow fraction and cumulative fraction are measured. At a yield of 21 wt% of the deasphalted oil product, the carbon residue value of the fraction is 2.16 wt%.

[0045] The specific embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A method for preparing deasphalted oil by solvent deasphalting, comprising: Using petroleum residue as the feedstock oil, and using an alkane solvent with a carrier added as the extractant to extract the petroleum residue, the obtained extract is the deasphalted oil; preferably, the petroleum residue contains a carrier. The carrier in the extractant and the carrier in the feedstock oil are each independently selected from at least one of isooctyl phosphate, tris(4-nonylphenyl) phosphite, triphenyl phosphate, tris(2,2,3,3-tetrafluoropropyl) phosphate, 2,2,2-trifluoroethanol, and 2-propylaniline.

2. The method according to claim 1, wherein The addition amount of the carrier in the feedstock oil accounts for 0.5 wt% to 5.0 wt% of the mass of the petroleum residue.

3. The method according to claim 2, wherein The mass ratio of the addition amount of the carrier in the extractant to the mass of the petroleum residue is 0.5 wt% to 5.0 wt%.

4. The method according to claim 1, wherein The mass ratio of the alkane solvent to the petroleum residue is 3:1 to 8:

1.

5. The method according to claim 1, characterized in that, The alkane solvent is an alkane with 3 to 5 carbon atoms; preferably, the alkane solvent includes at least one of propane, butane, and pentane, and propane is preferred.

6. The method according to claim 1, characterized in that, The operating pressure of the extraction is 4.0 to 8.0 MPa; the extraction temperature is 50 to 190 °C.

7. The method according to claim 1 or 6, characterized in that, The extraction tower is operated in a constant-pressure and temperature-lowering mode; the temperature ranges at various parts of the extraction tower are: 70 to 190 °C at the top, 60 to 180 °C in the middle of the tower, and 50 to 170 °C at the bottom of the tower. Preferably, it is 100 to 140 °C at the top of the tower, 90 to 130 °C in the middle of the tower, and 80 to 120 °C at the bottom of the tower.

8. The method according to claim 7, wherein The temperature at various parts of the extraction tower: the temperature at the top of the tower is at least 10 to 20 °C higher than that in the middle of the tower; the temperature in the middle of the tower is at least 10 to 20 °C higher than that at the bottom of the tower.

9. The method according to claim 1, wherein The operating process of the extraction is as follows: The extractant enters the tower from the bottom along with the solvent and flows upward, and the petroleum residue enters the tower from the middle of the tower and flows downward. The petroleum residue and the extractant contact in a countercurrent convection in the tower. The residue is discharged from the bottom of the tower, and the extract is discharged from the upper part of the tower; the extract is the target product deasphalted oil.

10. The method according to claim 1, wherein The petroleum residue is the residue obtained by the atmospheric or vacuum distillation of crude oil; the properties of the petroleum residue are: the asphaltene content is 2 wt% to 10 wt%; the 10% distillation point ≥ 500 °C, preferably 500 to 520 °C; the softening point is 25 to 45 °C.