METHOD AND DEVICE FOR PRODUCING NEEDLE COKE FROM MIXED OIL FEEDSTOCK

Claims

1. A method for producing needle coke, comprising the following stages: (1) hydrotreating a mixture of the first crude oil and the second crude oil to obtain a hydrogenated product; (2) cracking the hydrogenated product to produce a cracked product; (3) obtaining needle coke from cracked product as starting material, wherein the first feedstock oil has an aromatic carbon ratio of more than 65 mol.% (preferably 70-95 mol.%), the second feedstock oil has an aromatic carbon ratio of more than 60 mol.% (preferably 70-90 mol.%), the first feedstock oil has a coking onset temperature lower than the coking onset temperature of the second feedstock oil by 10-140°C, preferably by 35-105°C.

2. The method according to claim 1, wherein the weight ratio of said second feedstock oil to said first feedstock oil is 1:1-1:0.001, preferably 1:0.2-1:0.

01.

3. The method according to claim 1, wherein said first feedstock oil has a coking onset temperature of 350-420°C, preferably 380-415°C, and said second feedstock oil has a coking onset temperature of 430-490°C, preferably 450-485°C.

4. The method according to claim 1, wherein said second feedstock oil is a catalytic suspension in an oil product, and said first feedstock oil is an ethylene resin extract.

5. The method according to claim 1, wherein said second feedstock oil has an ash content of no more than 0.01 wt.%, preferably no more than 0.005 wt.% and a sulfur content of more than 0.5 wt.%, preferably 0.8-1.5 wt.%, and said first feedstock oil has an ash content of no more than 0.01 wt.%, preferably no more than 0.005 wt.% and a sulfur content of no more than 0.1 wt.%, preferably no more than 0.03 wt.%.

6. The method according to claim 1, wherein said first raw oil is obtained in accordance with the following stages: (i) extracting the ethylene resin with a solvent to produce an extraction phase and a raffinate phase; (ii) removing the solvent from the extraction phase to obtain an aromatic hydrocarbon-rich oil and subsequently separating said aromatic hydrocarbon-rich oil to obtain a first lighter oil and said first crude oil (i.e., a first heavier oil).

7. The method according to claim 6, wherein said solvent is selected from normal alkanes C3-C12 or cycloalkanes, preferably from normal alkanes C5-C12, and / or the weight ratio of said ethylene resin to said solvent is 1:0.5-1:5, preferably 1:1-1:

2.

8. The method according to claim 6, wherein said extraction is carried out at a temperature of 30-110°C, preferably 40-80°C.

9. The method according to claim 6, wherein said first heavier oil has a 5% distillation temperature of 300-400°C, preferably 340-380°C.

10. The method according to claim 6, wherein said first lighter oil has a 95% distillation temperature of 280-400°C, preferably 335-380°C, and / or said first lighter oil is subjected to a condensation reaction to obtain a condensation product, and then said condensation product is used to obtain petroleum coke.

11. The method according to claim 10, wherein the operating conditions of the condensation reaction include: a reaction temperature of 350-530°C, preferably 380-450°C, a reaction pressure of 0.01-5 MPa, preferably 1-3 MPa, a residual time of 0.1-15 h, preferably 0.5-6 h.

12. The method of claim 1, wherein prior to cracking the hydrogenated product is separated to obtain a lighter component such as gas, naphtha, and hydrogenated tail oil, and then the hydrogenated tail oil is cracked to obtain a cracked product.

13. The method according to claim 1, wherein the operating conditions for said hydrotreating include: a reaction temperature of 310-450°C, preferably 340-390°C, a reaction pressure of 2-20 MPa, preferably 4-8 MPa, a hydrogen / oil volume ratio of 100-2500, preferably 800-1800, a liquid hourly space velocity (LHSV) of 0.1-2.0 h -1 , preferably 0.6-1.2 h -1 .

14. The method according to claim 12, wherein said hydrogenated tail oil has a 5% distillation temperature of 160-250°C, preferably 180-210°C, and / or said hydrogenated tail oil has a sulfur content of no more than 0.4 wt.%, preferably no more than 0.35 wt.%.

15. The method of claim 1, wherein, prior to being used to produce needle coke, said cracked product is separated to produce a second lighter oil, an intermediate distillate oil, and a second heavier oil, and then said intermediate distillate oil is used as a feedstock for producing needle coke.

16. The method according to claim 15, wherein the operating conditions of said cracking include: a reaction temperature of 380-520°C, preferably 420-490°C, a reaction pressure of 0.1-5 MPa, preferably 0.2-1.0 MPa, a residual time of 0.01-30 h, preferably 0.1-3 h, an oil / steam weight ratio of 100:0.1-100:20, preferably 100:1-100:

8.

17. The method according to claim 15, wherein said intermediate distillate oil has a distillation range of 330-530°C, preferably 350-500°C.

18. The method according to claim 15, wherein said second lighter oil has a 95% distillation temperature of 300-400°C, preferably 320-380°C, and said second heavier oil has a 5% distillation temperature of 460-550°C, preferably 485-510°C.

19. The method according to claim 15, wherein at least a portion of said second lighter oil is recycled back to said hydrotreating step; or at least a portion of said second lighter oil is subjected to a condensation reaction to produce a condensation product, and then said condensation product is used to produce petroleum coke; or a portion of said second lighter oil is recycled back to said hydrotreating step and another portion is subjected to a condensation reaction.

20. The method according to claim 6, wherein said raffinate phase and said second heavier oil are mixed and then the resulting mixture is used to produce petroleum coke, and / or the weight ratio of said raffinate phase to said second heavier oil is 1:1-0.01:1, preferably 0.5:1-0.1:

1.

21. The method according to claim 10 or 20, wherein the operating conditions for obtaining petroleum coke include: a temperature at the outlet of the heating furnace of 440-550°C, preferably 490-510°C, a maximum pressure in the coke chamber of 0.01-2.5 MPa, preferably 0.1-0.5 MPa, and a reaction duration of 10-48 hours, preferably 18-30 hours.

22. The method according to claim 1, wherein the operating conditions for obtaining said needle coke are as follows: the temperature at the outlet of the heating furnace is 420-560°C, preferably 440-530°C, the maximum pressure in the coke chamber is 0.01-2.5 MPa, preferably 0.2-1.3 MPa, the reaction duration is 10-72 h, preferably 32-54 h.

23. A device for producing needle coke, which contains the following blocks: a feedstock oil supply unit which is configured to supply the first feedstock oil and the second feedstock oil; a hydrogenation unit which is configured to perform hydrotreating of a mixture of the first crude oil and the second crude oil to obtain a hydrogenated product; a cracking unit configured to crack the hydrogenated product to obtain a cracked product; a needle coke production unit which is configured to produce needle coke from a cracked product as a starting material, wherein the first feedstock oil has an aromatic carbon ratio of more than 65 mol.%, preferably 70-95 mol.%, the second feedstock oil has an aromatic carbon ratio of more than 60 mol.%, preferably 70-90 mol.%, and the first feedstock oil has a coking onset temperature lower than the coking onset temperature of the second feedstock oil by 10-140°C, preferably by 35-105°C.

24. The device according to item 23, which contains the following blocks: an extraction unit which is designed to obtain ethylene resin and solvent and then process them to obtain an extraction phase and a raffinate phase; a solvent extraction unit which is configured to receive the extraction phase from the extraction unit and then separate it to obtain regenerated solvent and aromatic hydrocarbon-enriched oil; a first separation unit which is configured to receive oil enriched with aromatic hydrocarbons from the solvent extraction unit and then process it to obtain a first lighter oil and a first heavier oil (corresponding to said first raw oil); a hydrogenation reaction unit which is configured to receive said first feedstock oil and a catalytic suspension in an oil product (corresponding to said second feedstock oil), which are then subjected to a hydrogenation reaction in the presence of hydrogen gas and a hydrogenation catalyst; a hydrogenation separation unit which is configured to receive the hydrogenated product from the hydrogenation reaction unit and then separate it to obtain gas, naphtha and hydrogenated tail oil; a cracking reaction unit which is configured to receive hydrogenated tail oil from a hydrogenation separation unit and then subject it to a cracking reaction in the presence of a carrier gas; a second separation unit which is configured to receive the cracked product from the cracking reaction unit and then separate it to obtain a second lighter oil, an intermediate distillate oil and a second heavier oil; and a needle coke production unit which is configured to receive said intermediate distillate oil and then subject it to a reaction to produce needle coke.