CN112745956A

CN112745956A - Method for processing inferior residual oil

Info

Publication number: CN112745956A
Application number: CN201911047030.7A
Authority: CN
Inventors: 王翠红; 申海平; 王红; 刘自宾; 廖志新; 范启明; 佘玉成
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2019-10-30
Filing date: 2019-10-30
Publication date: 2021-05-04
Anticipated expiration: 2039-10-30
Also published as: CN112745956B

Abstract

The invention relates to the field of residual oil processing, and discloses a method for processing inferior residual oil, which comprises the following steps: introducing vacuum residue into a first separator to perform countercurrent contact with a solvent contained in the first separator to respectively obtain a first overhead material flow and a first kettle material flow; introducing the first overhead stream into a second separator for countercurrent contact with a solvent contained therein to obtain a second overhead stream and a second bottoms stream, respectively; carrying out hydrotreating on the second tower bottom material flow to obtain a hydrogenated material flow; and carrying out delayed coking treatment on the hydrogenated material flow to obtain an anode coke product. The method realizes the high-efficiency utilization of the inferior residual oil, improves the utilization rate and the utilization value of the inferior residual oil to the maximum extent, and the produced anode coke has higher quality.

Description

Method for processing inferior residual oil

Technical Field

The invention relates to the field of hydrocarbon oil processing, in particular to a method for processing inferior residual oil.

Background

With the rapid development of the electrolytic aluminum industry, the demand for prebaked anode coke for aluminum has increased greatly, and the prebaked anode coke for aluminum industry has gradually become a new investment growth point.

Generally, when the sulfur content of petroleum coke is lower, the consumption of the anode is reduced along with the increase of the sulfur content, because the sulfur increases the coking rate of asphalt and reduces the void ratio of asphalt coking; meanwhile, sulfur is combined with metal impurities, so that the catalytic action of the metal impurities is reduced, but if the sulfur content is too high, the thermal brittleness of the carbon anode is increased, the sulfur is mainly converted into a gas phase in the form of oxides in the electrolytic process, the electrolytic environment is seriously affected, the environmental protection pressure is high, and in addition, an iron sulfide film can be generated on an anode rod to increase the voltage drop.

Thus, in producing anode coke feedstocks, feedstocks with low asphaltenes, low sulfur, low metals content, and lower saturates content should be selected.

With the continuous development of the oil refining industry, the processing capacity of crude oil is improved year by year, and the heavy and inferior degrees of the crude oil are gradually increased, so that the properties of residual oil are increasingly poor, which is shown in that the contents of metal, carbon residue, asphaltene, sulfur and nitrogen are increasingly high, the properties of raw materials for producing anode coke are increasingly poor, and the difficulty in producing qualified anode coke products is increasingly high.

The existing anode coke (paste) production process usually adopts medium-temperature asphalt or/and high-temperature asphalt as raw materials.

However, it is possible to use a single-layer,when the anode paste produced by adopting the medium-temperature asphalt as the raw material is used, the smoke generated due to high volatile content is large, and the environment is polluted; when high-temperature asphalt is adopted as a raw material, because the high-temperature asphalt has high sulfur content, high metal content and high carbon residue value, shot coke is easily generated during coke formation, and SO is discharged during use of the generated coke_xAffecting the environment.

CN1349955A discloses a method for producing clean anode coke, which comprises the steps of uniformly mixing raw material petroleum coke and medium temperature asphalt, removing impurities by using an electromagnetic separator, crushing, forming, roasting at 1000-1300 ℃ for 12-24 h, and cooling the mature anode coke by a cooling tower to obtain a clean anode coke product; the electromagnetic separator has a separating effect only on free metal impurities and has no separating effect on metal compounds, sulfur and the like.

At present, no suitable process is available for treating vacuum residue with poor properties, so that the vacuum residue can be used as a raw material for producing high-quality anode coke: the fixed bed residue hydrogenation can remove sulfur and metals in the vacuum residue, but the fixed bed residue hydrogenation has poor economical efficiency in consideration of the construction cost of a hydrogenation device, hydrogen consumption and the service cycle of a catalyst. In addition, the vacuum residue is hydrogenated and then used as coking feed, the saturation degree of the feeding of a coking device is greatly increased, and the properties of volatile carbon-containing substances, the pile ratio, the moldability and the like of the produced anode coke are difficult to meet the quality requirement of the anode coke.

Disclosure of Invention

The invention aims to overcome the problems in the prior art and provide a method for processing inferior residual oil so as to achieve the purpose of separating high-quality anode coke raw material from inferior residual oil to produce qualified anode coke.

In order to achieve the above objects, the present invention provides a method for processing inferior residual oil, comprising:

(1) introducing vacuum residue into a first separator to perform countercurrent contact with a solvent contained in the first separator to respectively obtain a first overhead material flow and a first kettle material flow;

(2) introducing the first overhead stream into a second separator for countercurrent contact with a solvent contained therein to obtain a second overhead stream and a second bottoms stream, respectively;

(3) carrying out hydrotreating on the second tower bottom material flow to obtain a hydrogenated material flow;

(4) and carrying out delayed coking treatment on the hydrogenated material flow to obtain an anode coke product.

The invention adopts the vacuum residue oil as the raw material for producing the anode coke, and can avoid the situation of competing with the production of the needle coke (the price of the needle coke is higher than that of the anode coke) for the raw material (the oil slurry is a high-quality raw material for producing the needle coke after pretreatment), thereby producing more products with high added values on the basis of ensuring the original high added value products of enterprises.

The method ensures that the anode coke generated by the obtained anode coke raw material through the delayed coking reaction has high volatilization temperature and low content of volatile components, and the anode coke can keep a good environment in the using process; in addition, the method of the invention separates and removes the components which are difficult to coke and the components which are easy to generate shot coke, so that the efficiency of generating the anode coke is high and the quality of the anode coke is good.

In addition, the rest components obtained by the method can be used as raw materials and/or blending components of catalytic cracking raw materials, building asphalt and hard road asphalt, so that the added value of the product is improved, and zero delivery of heavy oil is realized.

Drawings

FIG. 1 is a process flow diagram for processing low grade residue according to a preferred embodiment of the present invention.

Description of the reference numerals

1. Vacuum residue 2, first solvent 3 and first separator

4. Second separator 5, first overhead stream 6, second overhead stream

7. Catalytic cracking unit 8, first tower bottom material flow 9 and retreatment device

10. Second tower bottom material flow 11, hydrotreater 12 and gas-liquid separation device

13. Delayed coking unit 14, second solvent

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

As previously mentioned, the present invention provides a process for processing low grade residue oil, comprising:

Preferably, the method further comprises: subjecting the second overhead stream obtained in step (2) to a catalytic cracking treatment.

Preferably, the catalytic cracking treatment is carried out in the presence of a catalytic cracking catalyst, and the conditions of the catalytic cracking treatment comprise: the reaction temperature is 480-550 ℃, the oil gas retention time is 1-5s, the reaction pressure is 0.05-0.5MPa, and the mass ratio of the agent to the oil is 4-12.

The present invention does not particularly require the kind of the catalytic cracking catalyst, and various catalytic cracking catalysts conventionally used in the art may be used, and for example, the catalytic cracking catalyst contains 1 to 60 wt% of a zeolite mixture, 5 to 99 wt% of a refractory inorganic oxide, and 0 to 70 wt% of clay, based on the total weight of the catalytic cracking catalyst, wherein the zeolite mixture contains 1 to 75 wt% of Y zeolite and 1 to 75 wt% of zeolite having an MFI structure, based on the total weight of the zeolite mixture. Preferably, the catalytic cracking catalyst comprises 10-50 wt% of zeolite mixture, 10-70 wt% of refractory inorganic oxide and 0-60 wt% of clay based on the total weight of the catalytic cracking catalyst.

Because the content of saturated hydrocarbon in the second tower top material flow obtained in the step (2) is high, when the second tower top material flow is used as a catalytic cracking raw material, light oil products with high added values, such as low-carbon olefin, gasoline, diesel oil and the like, can be produced.

Preferably, the second overhead stream has a saturated hydrocarbon content of from 35 to 80 wt%.

Preferably, the solvent contained in the first separator and the second separator is the same or different, and each is independently selected from at least one of propane, butane, pentane.

Preferably, the operating conditions in the first separator comprise: the operation temperature (including the operation temperature at the top of the tower and the operation temperature at the bottom of the tower) is 30-240 ℃, the operation pressure is 2.0-10.0 MPa, and the weight ratio of the solvent to the oil is 1.0-5.0: 1. More preferably, the operating conditions in the first separator include: the operation temperature (including the operation temperature at the top of the tower and the operation temperature at the bottom of the tower) is 45-220 ℃, the operation pressure is 3.5-8.0 MPa, and the weight ratio of the solvent to the oil is 1.5-4.5: 1.

In the operating conditions of the first separator, the solvent-to-oil weight ratio refers to the weight ratio of solvent to vacuum residue.

Preferably, the operating conditions in the second separator comprise: the operation temperature (including the operation temperature at the top of the tower and the operation temperature at the bottom of the tower) is 45-260 ℃, the operation pressure is 2.0-10.0 MPa, and the weight ratio of the solvent to the oil is 0.1-4.0: 1. More preferably, the operating conditions in the second separator include: the operation temperature (including the operation temperature at the top of the tower and the operation temperature at the bottom of the tower) is 50-240 ℃, the operation pressure is 3.5-8.0 MPa, and the weight ratio of the solvent to the oil is 0.5-3.0: 1.

In the operating conditions of the second separator, the weight ratio in the solvent-oil refers to the weight ratio of solvent to first overhead stream.

Preferably, in step (3), the hydrotreating is carried out in the presence of a hydrogenation protection catalyst and a hydrofinishing catalystThe hydrotreating conditions include: the reaction temperature is 300-420 ℃, the hydrogen partial pressure is 2-12 Mpa, and the volume space velocity is 0.2h^-1-1.5^-1Hydrogen to oil volume ratio of 200Nm³/m³-900Nm³/m³。

Illustratively, the hydrogenation protection catalyst is Raschig ring-shaped and comprises an alumina carrier and molybdenum and/or tungsten and nickel and/or cobalt, wherein the molybdenum and/or tungsten is/are loaded on the alumina carrier, and the content of the molybdenum and/or tungsten is 1-10 wt% and the content of the nickel and/or cobalt is 0.5-3 wt% in terms of oxides based on the total weight of the hydrogenation protection agent; the alumina is preferably gamma-alumina, and the pore volume of the hydrogenation protection catalyst is not less than 0.5 ml/g.

Preferably, the hydrofining catalyst contains a carrier and an active metal element loaded on the carrier, wherein the active metal element is at least one of molybdenum, tungsten, nickel and cobalt, and the carrier is alumina or a combination of alumina and silica.

More preferably, in the hydrofinishing catalyst, the active metal element is a combination of molybdenum and/or tungsten as component a and nickel and/or cobalt as component B.

Particularly preferably, the content of the component A is 8 to 20% by weight and the content of the component B is 0.3 to 8% by weight, based on the total weight of the hydrofining catalyst and based on the oxide of the active metal element.

Particularly preferably, in the hydrofinishing catalyst, the pore volume of the carrier is distributed such that the pore volume of 60 to 100 angstroms in diameter accounts for 75 to 98% of the total pore volume, and more preferably the pore volume of the hydrofinishing catalyst is not less than 0.4 ml/g.

The loading volume ratio of the hydrogenation protection catalyst and the hydrofinishing catalyst is not particularly limited in the present invention, and those skilled in the art can load the hydrogenation protection catalyst and the hydrofinishing catalyst by using the loading ratio conventionally used in the art.

Preferably, in step (4), the delayed coking process is carried out in a delayed coking unit, the operating conditions in the delayed coking unit comprising: the outlet temperature of the heating furnace is controlled to be 480-520 ℃, the pressure of the coke tower is 0.1-0.5 Mpa, and the circulation ratio is 0.5-1.6.

In the method of the present invention, the anode coke product obtained in the step (4) can be obtained as well as, for example, coker dry gas, coker gasoline, coker diesel oil, coker gas oil, and the like.

According to a preferred embodiment, in step (1), the first bottom stream obtained can be used directly as a feedstock for delayed coking to produce petroleum coke, or can be blended with slurry oil or soft residue to produce petroleum coke as a feedstock for delayed coking.

According to another preferred embodiment, the first column bottoms stream can also be used directly as construction and hard road asphalt, and/or as a blending component for the production of construction and hard road asphalt.

Preferably, the method further comprises: introducing the first column bottoms stream obtained in step (1) into a reprocessing apparatus for processing. It is particularly preferred that the reprocessing unit is a coker and/or an asphalt compounder.

The present invention has no particular limitation on the specific operation conditions of the reprocessing device, for example, the blending temperature is 150 ℃ and 200 ℃, and the blending time is 10-60 min.

Preferably, the vacuum resid has at least one of the following characteristics:

(a) viscosity of not less than 5000mm at 100 deg.C²/s；

(b) A carbon residue value of not less than 20% by weight;

(c) the total content of Ni and V is not less than 150 ug/g.

Unless otherwise specified, all pressures described herein are expressed as gauge pressure.

A preferred embodiment of the method of processing low grade residue according to the present invention is provided below with reference to the accompanying drawings.

As shown in FIG. 1, a vacuum residue 1 and a first solvent 2 enter a first separator 3 from the upper part and the lower part of the first separator 3 respectively, the vacuum residue 1 and the first solvent 2 are in countercurrent contact in the first separator 3, a first bottom stream 8 extracted from the bottom of the first separator 3 enters a reprocessing device 9 (the reprocessing device 9 is a coking device and/or an asphalt blending device), a first overhead stream 5 extracted from the top of the first separator 3 enters from the middle upper part of a second separator 4, a second solvent 14 enters from the middle lower part of the second separator 4 and is in countercurrent contact in the second separator 4, a second overhead stream 6 extracted from the top of the second separator 4 enters a catalytic cracking device 7 for catalytic cracking, a second bottom stream 10 extracted from the bottom of the second separator 4 enters a hydrotreating device 11 for hydrotreating, obtaining a hydrogenation material flow, feeding the hydrogenation material flow extracted from the bottom of the hydrotreatment device 11 into a gas-liquid separation device 12 for gas-liquid separation to obtain an anode coke feed flow, and introducing the anode coke feed flow into a delayed coking device 13 to produce an anode coke product.

The present invention will be described in detail below by way of examples. In the following examples, various raw materials used below were all commercially available without specific description. The properties of the vacuum resid feed used below are shown in table 1.

The hydrofining catalyst RMS-30 and the hydrogenation protection catalyst RG-30B are commercial agents produced by ChangLing catalyst division of China petrochemical catalyst, Inc.

The catalyst CDOS-WH is a catalytic cracking catalyst available from the guru catalyst division, chinese petrochemical catalyst, inc.

The following viscosity data: the dynamic viscosity is measured according to NB/SH/T0739-.

The following examples, without specific reference thereto, were carried out using the process flow shown in fig. 1, and the detailed flow of each example is not described in detail below, and those skilled in the art should not be construed as limiting the present invention.

Example 1

The first solvent and the second solvent used in this example are the same and are both n-butane, and the first solvent and the second solvent are from the same solvent storage unit and are controlled only by different pipelines with valves.

The hydrotreater of this example was a fixed bed hydrogenation reactor.

The catalytic cracking unit of this example was a riser reactor, wherein the catalytic cracking catalyst was catalyst CDOS-WH.

The first bottoms stream from the bottom of the first separator was blended with a base asphalt (properties listed in Table 8) in an asphalt blending unit to provide a hard asphalt having the properties listed in Table 9.

The specific reaction conditions referred to in the above examples are shown in table 2, the compositions and properties of the first bottoms stream, the second bottoms stream and the second overhead stream are shown in table 3, the composition of the resulting hydrogenated stream and the properties of the anode coke feed stream are shown in table 4, the composition of the resulting coked product and the properties of the anode coke are shown in table 5, the composition of the resulting catalytically cracked product is shown in table 6, and the composition of the first bottoms stream and the properties of the resulting hard pitch are shown in table 7.

Example 2

This example was carried out using the same process flow as example 1, except that some of the specific parameters involved in the flow were different from example 1, and the specific parameters and results are shown in the following table.

Comparative example 1

Vacuum residue is processed in the same manner as in example 1, except that the vacuum residue feedstock is not passed through the first separator, the second separator and the hydrotreatment of the present invention, but is directly fed as a feedstock for preparing anode coke to the same delayed coking unit as in example 1 for delayed coking treatment to obtain a coking product containing anode coke.

The specific reaction conditions involved in this comparative example are shown in Table 2, and the composition of the coking products and the properties of the anode coke are shown in Table 5.

Comparative example 2

Vacuum residue was processed according to the method of example 1, except that the vacuum residue feedstock was not subjected to the separation treatment of the first separator and the second separator of the present invention, but the vacuum residue feedstock was directly fed to the same hydrotreater as in example 1 to be subjected to hydrotreatment, and then the resulting hydrogenated stream was fed to the same gas-liquid separator as in example 1 to be subjected to gas-liquid separation, to obtain an anode coke feed stream, and the anode coke feed stream was fed to the same delayed coking unit as in example 1 to produce an anode coke product.

The specific reaction conditions involved in this comparative example are shown in table 2, the composition of the hydrogenation stream and the properties of the anode coke feed stream are shown in table 4, and the composition of the coking product and the properties of the anode coke are shown in table 5.

TABLE 1

TABLE 2

Item	Example 1	Example 2	Comparative example 1	Comparative example 2
					First separator			/	/
Solvent-oil weight ratio	2.5:1	3.0:1	/	/
					Operating pressure	4.5Mpa	7Mpa	/	/
Operating temperature at the top of the column	125℃	185℃	/	/
					Operating temperature at the bottom of the column	115℃	175℃	/	/
Second separator			/	/
					Solvent-oil weight ratio	0.8:1	1.5:1	/	/
Operating pressure	4Mpa	7Mpa	/	/
					Operating temperature at the top of the column	143℃	210℃	/	/
Operating temperature at the bottom of the column	130℃	200℃	/	/
					Hydrotreater			/
Hydrogenation protection catalyst: volume ratio of hydrorefining catalyst	17：83	25:75	/	17:83
					Partial pressure of hydrogen/Mpa	5.5Mpa	6.5Mpa	/	7.5Mpa
Reaction temperature/. degree.C	375℃	392℃	/	400℃
					Hydrogen to oil ratio/(Nm)³/m³)	500	700	/	900
Volume space velocity/h^-1	1.2	0.8	/	1.2
					Delayed coking device
Outlet temperature of heating furnace	495℃	500℃	495℃	495℃
					Coke drum pressure	0.3Mpa	0.4Mpa	0.3Mpa	0.3Mpa
Circulation ratio	0.8	0.9	0.8	0.8
					Catalytic cracking unit			/	/
Reaction temperature	520℃	530℃	/	/
					Reaction pressure	0.35Mpa	0.15Mpa	/	/
Weight ratio of solvent to oil	7.2	9.5
					Oil gas residence timeM/s	2	3
Asphalt blending device			/	/
					Blending temperature	180℃	175℃	/	/
Blending time	30min	30min	/	/
					Weight ratio of matrix asphalt to first tower bottom material flow	29：21	38:19	/	/

TABLE 3

TABLE 4

TABLE 5

TABLE 6

Table 7: first column bottom stream Properties

	Example 1	Example 2
			Penetration (25 ℃,100g,5s)/(1/10mm)	0	0
Softening point/. degree.C	137.5	148.3

Table 8: properties of the base asphalt

Table 9: properties of blended asphalt

	Example 1	Example 2
			Weight ratio of matrix asphalt to first tower bottom material flow	29:21	38:19
High modulus asphalt penetration (25 ℃,100g,5s)/(1/10mm)	37	45
			High modulus asphalt 60 ℃ dynamic shear modulus/kPa	23.7	21.5
High modulus asphalt PG classification	PG82-16	PG82-16

From the results, the qualified anode coke product can be obtained by processing the vacuum residue by adopting the method, the performance index of the anode coke product is superior to that of comparative example 1 which directly uses the vacuum residue as the raw material for preparing the anode coke, and the coke breeze amount, the sulfur content, the ash content, the volatile matter and the solid carbon index of the anode coke obtained in the comparative example 1 can not meet the requirements.

As can be seen by comparing example 1 with comparative example 2, the performance index of the anode coke obtained in example 1 under the preferable conditions of the hydrotreating conditions is better, while the coke breeze amount, the sulfur content, the ash content, the volatile matter and the solid carbon index of the anode coke obtained in comparative example 2 can not meet the requirements.

From the above results, it can be seen that the second overhead stream obtained by separating the vacuum residue by the method of the present invention can produce more light oil products through catalytic cracking reaction.

From the above results, it can be seen that the blending of the first bottoms stream obtained by separating the vacuum residue by the process of the present invention with the base asphalt results in a high modulus asphalt product.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims

1. A method of processing low grade residua, comprising:

2. The method of claim 1, wherein the method further comprises: subjecting the second overhead stream obtained in step (2) to a catalytic cracking treatment.

3. The process according to claim 1 or 2, wherein the solvent contained in the first separator and the second separator is the same or different and each is independently selected from at least one of propane, butane, pentane.

4. The method of any one of claims 1-3, wherein the operating conditions in the first separator comprise: the operation temperature is 30-240 ℃, the operation pressure is 2.0-10.0 MPa, and the weight ratio of the solvent to the oil is 1.0-5.0: 1;

preferably, the operating conditions in the first separator comprise: the operation temperature is 45-220 ℃, the operation pressure is 3.5-8.0 MPa, and the weight ratio of the solvent to the oil is 1.5-4.5: 1.

5. The method of any one of claims 1-3, wherein the operating conditions in the second separator comprise: the operation temperature is 45-260 ℃, the operation pressure is 2.0-10.0 MPa, and the weight ratio of the solvent to the oil is 0.1-4.0: 1;

preferably, the operating conditions in the second separator comprise: the operation temperature is 50-240 ℃, the operation pressure is 3.5-8.0 MPa, and the weight ratio of the solvent to the oil is 0.5-3.0: 1.

6. The process of any one of claims 1-5, wherein in step (3), the hydrotreating is carried out in the presence of a hydrogenation protection catalyst and a hydrofinishing catalyst, and the conditions of the hydrotreating comprise:the reaction temperature is 300-420 ℃, the hydrogen partial pressure is 2-12 MPa, and the volume space velocity is 0.2h^-1-1.5^-1Hydrogen to oil volume ratio of 200Nm³/m³-900 Nm³/m³。

7. The process according to claim 6, wherein the hydrorefining catalyst comprises a carrier and an active metal element supported on the carrier, the active metal element being at least one selected from molybdenum, tungsten, nickel and cobalt, and the carrier being alumina or a combination of alumina and silica;

preferably, the active metal element is a combination of molybdenum and/or tungsten as component a and nickel and/or cobalt as component B;

preferably, the content of the component A is 8-20 wt% and the content of the component B is 0.3-8 wt% based on the total weight of the hydrofining catalyst and the oxide of the active metal element.

8. The method of any one of claims 1-5, wherein in step (4), the delayed coking process is carried out in a delayed coking plant, the operating conditions in the delayed coking plant comprising: the outlet temperature of the heating furnace is controlled to be 480-520 ℃, the pressure of the coke tower is 0.1-0.5 MPa, and the circulation ratio is 0.5-1.6.

9. The method of any of claims 1-5, wherein the method further comprises: introducing the first bottoms stream obtained in step (1) into a coker and/or pitch conditioner for processing.

10. The process of any of claims 1-5, wherein the vacuum resid has at least one of the following characteristics:

(a) viscosity of not less than 5000mm at 100 deg.C²/s；

(b) A carbon residue value of not less than 20% by weight;

(c) the total content of Ni and V is not less than 150 ug/g.