CN109486518B

CN109486518B - Method and system for modifying low-quality oil

Info

Publication number: CN109486518B
Application number: CN201710814175.XA
Authority: CN
Inventors: 侯焕娣; 董明; 申海平; 王子军; 龙军; 王玉章; 张书红; 王翠红; 李吉广; 陶梦莹; 许可; 赵飞
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: 2017-09-11
Filing date: 2017-09-11
Publication date: 2021-01-08
Anticipated expiration: 2037-09-11
Also published as: CN109486518A

Abstract

The invention relates to a method and a system for upgrading low-quality oil, wherein the method comprises the following steps: (1) carrying out conversion reaction on low-quality oil serving as a modified raw material in a conversion reactor under a hydrogen condition to obtain a conversion product; (2) separating the conversion product obtained in the step (1) to obtain at least a first separated product; (3) extracting and separating the first separation product obtained in the step (2) in an extraction and separation unit to obtain modified oil and residue; (4) returning the residue obtained in the step (3) to the step (1) for the conversion reaction; or, throwing the residue obtained in the step (3) outwards; or returning part of the residue obtained in the step (3) to the step (1) for the conversion reaction, and throwing the rest of the residue outwards. The invention provides a reforming method and a system, which can maintain the long-time operation of the system under the condition of reducing the external throwing residue as little as possible.

Description

Method and system for modifying low-quality oil

Technical Field

The invention relates to a method and a system for upgrading low-quality oil.

Background

In recent years, the trend toward lower quality fossil fuels has been increasing year by year. Moreover, the production of low-quality fuel oils such as residual oils, low-grade oils, shale oils, oil sand heavy oils, and coal derived oils has increased year by year. Such low quality oils are characterized by high density, high viscosity, high content of heteroatoms (sulfur, nitrogen, heavy metals) or high asphaltene content. In addition, the existing processing technology (such as delayed coking) developed aiming at the low-quality oil has the problems of high coke yield, low energy effective utilization rate, poor economic benefit, non-environmental-friendly production process and the like. Therefore, further development of efficient and green upgrading technology for such low-quality oil has become one of development direction and research focus of petrochemical industry.

Chinese patent CN200310104918.2 discloses a method for modifying inferior heavy and residual oil, which comprises subjecting heavy and residual oil to mild hydrocracking in a suspension bed to remove most or all metal impurities from colloid and asphaltene; the obtained hydrogenation product passes through a metal adsorption reactor which can be switched to operate or can replace the added materials on line, and free metal impurities in the suspension bed hydrocracking oil are adsorbed and removed; and (3) sending the demetallized product into a residual oil fixed bed hydrotreater for deep hydrogenation to remove other impurities, and producing high-quality heavy oil catalytic cracking raw materials.

US patent 20130112593a1 discloses a heavy crude oil, distillation residue conversion process that achieves upgrading of heavy oil by combining solvent deasphalting, hydrotreating, distillation, and gasification. But the yield of the modified oil of the heavy residual oil processed by the method is only 75-85%, and the content of metal (Ni + V) in the modified oil is more than 100 microgram/gram.

Disclosure of Invention

The invention aims to provide a method and a system for upgrading low-quality oil, which can maintain the operation of the system for a long time under the condition of reducing the outward throwing residue as little as possible.

In order to achieve the above object, the present invention provides a method for upgrading low quality oil, the method comprising:

(1) carrying out conversion reaction on low-quality oil serving as a modified raw material in a conversion reactor under a hydrogen condition to obtain a conversion product; wherein the upgraded feedstock comprises at least one bituminous component selected from the group consisting of asphaltenes, asphaltenes and preasphaltenes, the conversion of the conversion reaction is from 30 to 70 wt%, the conversion of the conversion reaction being (weight of components in the upgraded feedstock having a distillation range above 524 ℃ C. — weight of components in the converted product having a distillation range above 524 ℃ C.)/weight of components in the upgraded feedstock having a distillation range above 524 ℃ x 100 wt%;

(2) separating the conversion product obtained in the step (1) to obtain at least a first separated product; wherein, in the first separation product, the content of the components with the distillation range below 350 ℃ is not more than 5 weight percent, and the content of the components with the distillation range between 350 ℃ and 524 ℃ is 20-60 weight percent;

(3) extracting and separating the first separation product obtained in the step (2) in an extraction and separation unit to obtain modified oil and residue;

(4) returning the residue obtained in the step (3) to the step (1) for the conversion reaction; or, throwing the residue obtained in the step (3) outwards; or returning part of the residue obtained in the step (3) to the step (1) for the conversion reaction, and throwing the rest of the residue outwards.

The invention also provides a low-quality oil upgrading system, which comprises a conversion reactor, a separation treatment unit and an extraction separation unit; the conversion reactor is provided with a reaction material inlet and a conversion product outlet, the separation processing unit is provided with a processing raw material inlet and a first separation product outlet, and the extraction separation unit is provided with an extraction solvent inlet, an extraction raw material inlet, a modified oil outlet and a residue outlet; and a conversion product outlet of the conversion reactor is communicated with a processing raw material inlet of the separation processing unit, a first separation product outlet of the separation processing unit is communicated with an extraction raw material inlet of the extraction separation unit, and a residue outlet of the extraction separation unit is connected with a reaction material inlet of the conversion reactor.

Compared with the prior art, the invention has the following advantages:

1. the upgrading raw material can be upgraded to the upgraded oil which is rich in saturated structure, basically free of heavy metal and basically free of asphaltene with high efficiency and maximum. In preferred aspects, the conversion of upgraded feedstock is generally greater than 90 wt%, preferably greater than 95 wt%, the resulting upgraded oil generally has a heavy metal content (based on the total weight of nickel and vanadium) of less than 10 micrograms/gram, preferably less than 1 microgram/gram, and the upgraded oil generally has an asphaltene content of less than 2.0 wt%, preferably less than 0.5 wt%.

2. The upgrading method and the upgrading system provided by the invention have the advantages of stable operation, high upgrading efficiency, less three-waste emission, environmental protection, low coke yield, high upgrading oil yield, low yield of toluene insoluble substances in upgrading oil and the like.

3. On the one hand, the invention can maintain the long-time operation of the conversion reactor on the premise of realizing high conversion rate of the modified raw material, reduce the external throwing residue and improve the effective utilization rate of resources, on the other hand, the invention can prevent the excessive light components less than 350 ℃ in the first separation product from polluting the solvent and further causing the generation of black oil in the extraction separation process by optimizing the composition of the first separation product, and can prevent the problems of poor fluidity and difficult dissolution when the residue returns to carry out the conversion reaction by maintaining the components in the distillation range of 350-524 ℃ in the first separation product within a reasonable range.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

FIG. 1 includes a schematic flow diagram of one embodiment of the method of the present invention and also includes a schematic structural diagram of one embodiment of the system of the present invention.

Description of the reference numerals

1 pipeline 2 pipeline 3 pipeline

4 line 5 line 6 line

7 conversion reactor 8 line 9 high pressure separation unit

10 line 11 line 12 line

13 low pressure separation unit 14 line 15 line

16 extractive separation unit 17 line 18 line

19 line 20 line

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

In the present invention, the boiling point range refers to the boiling point range obtained by distilling an oil product at normal pressure (101325 Pa).

In the present invention, unless otherwise specified, the pressure refers to gauge pressure.

The invention provides a method for modifying low-quality oil, which comprises the following steps: (1) carrying out conversion reaction on low-quality oil serving as a modified raw material in a conversion reactor under a hydrogen condition to obtain a conversion product; wherein the upgraded feedstock comprises at least one bituminous component selected from the group consisting of asphaltenes, asphaltenes and preasphaltenes, the conversion of the conversion reaction is from 30 to 70 wt%, the conversion of the conversion reaction being (weight of components in the upgraded feedstock having a distillation range above 524 ℃ C. — weight of components in the converted product having a distillation range above 524 ℃ C.)/weight of components in the upgraded feedstock having a distillation range above 524 ℃ x 100 wt%; (2) separating the conversion product obtained in the step (1) to obtain at least a first separated product; wherein, in the first separation product, the content of components with the distillation range below 350 ℃ is not more than 5 weight percent, preferably less than 3 weight percent, the content of components with the distillation range between 350 and 524 ℃ (preferably 355 and 500 ℃ or 380 and 524 ℃, and further preferably 400 and 500 ℃) is 20 to 60 weight percent, preferably 25 to 55 weight percent, the initial distillation point of the first separation product is generally not lower than 300 ℃, preferably not lower than 330 ℃, and more preferably not lower than 350 ℃; (3) extracting and separating the first separation product obtained in the step (2) in an extraction and separation unit to obtain modified oil and residue; (4) returning the residue obtained in the step (3) to the step (1) for the conversion reaction; or, throwing the residue obtained in the step (3) outwards; or returning part of the residue obtained in the step (3) to the step (1) for the conversion reaction, and throwing the rest of the residue outwards.

The invention can maintain the long-time operation of the system under the condition of reducing the outward throwing of the residue as much as possible and improving the resource utilization rate, the conversion reactor and the extraction separation unit are the key for determining whether the system can operate for a long time, the conversion rate of the conversion reactor is as high as possible under the condition of system stability, light components less than 350 ℃ in the first separation product entering the extraction separation unit are not too much, otherwise, the solvent is polluted, black oil is generated in the extraction separation process, more components with the distillation range of 350 ℃ and 524 ℃ are needed, otherwise, the residue is not easy to flow and the conversion reaction is not easy to be carried out in the conversion reactor.

According to the present invention, the conversion rate of the conversion reaction is too high, which tends to cause coking and decrease the system operation time, while too low, which tends to cause excessive throwing residue and decrease the upgrading efficiency per unit time, and the inventors have found through a large number of experiments that the conversion rate of the conversion reaction of the present invention may be 30 to 70% by weight, preferably 30 to 60% by weight.

According to the invention, the conversion reaction is essentially a thermal conversion reaction, which means that the upgraded feedstock is thermally converted in the presence of hydrogen and a conversion product is obtained which comprises at least a first separation product, which may also comprise gaseous components and liquid products having a distillation range below the initial boiling point of the first separation product. The present invention is not particularly limited in terms of the conditions, catalyst and reactor for the conversion reaction, as long as the above-mentioned conversion rate can be achieved.

In one embodiment, the conversion reaction is carried out in a fluidized bed reactor using a solid-liquid suspension as a catalyst, so the conversion reactor can be a fluidized bed reactor, and the fluidized bed reactor is a reactor in which the reaction raw material and the catalyst are reacted in a flowing state, and generally comprises a slurry bed reactor and a fluidized bed reactor, and the slurry bed reactor is preferred in the invention.

In one embodiment, the conversion reaction is carried out in the presence or absence of a conversion catalyst, which may contain at least one selected from the group consisting of a group VB metal compound, a group VIB metal compound, and a group VIII metal compound, preferably at least one of a Mo compound, a W compound, a Ni compound, a Co compound, a Fe compound, a V compound, and a Cr compound; the conditions of the conversion reaction may include: the temperature is 380-470 ℃, preferably 400-440 ℃, the hydrogen partial pressure is 10-25 MPa, preferably 13-20 MPa, and the volume space velocity of the modified raw material is 0.01-2 hours^-1Preferably 0.1 to 1.0 hour^-1The volume ratio of the hydrogen to the modifying raw material is 500-5000, preferably 800-2000, and the amount of the converting catalyst is 10-50000 micrograms/g, preferably 30-25000 micrograms/g based on the weight of the modifying raw material and calculated by the metal in the converting catalyst.

According to the present invention, the upgraded feedstock may comprise at least one bituminous component selected from the group consisting of asphaltenes, asphaltenes and preasphatenes, preferably comprising asphaltenes and/or preasphatenes, more preferably comprising asphaltenes. Asphaltene is a substance that is insoluble in nonpolar small-molecule n-alkanes (such as n-pentane or n-heptane) and soluble in benzene or toluene in the upgraded material, asphaltene is a substance that is soluble in toluene and insoluble in n-hexane in the upgraded material, and preasphaltene is a substance that is soluble in tetrahydrofuran and insoluble in toluene in the upgraded material. The upgrading raw material preferably satisfies the conditions selected from the group consisting of API degree less than 27 and large distillation rangeAt 350 c (preferably greater than 500 c, more preferably greater than 524 c), an asphaltene content greater than 2 wt% (preferably greater than 5 wt%, more preferably greater than 10 wt%, even more preferably greater than 15 wt%), and a heavy metal content greater than 100 micrograms/gram based on the total weight of nickel and vanadium. Specifically, the upgraded feedstock may include at least one selected from the group consisting of low grade crude oil, heavy oil, deoiled bitumen, coal derived oil, shale oil, and petrochemical waste oil; the heavy oil refers to distillate oil or residual oil with a boiling point above 350 ℃, and the distillate oil generally refers to fraction products obtained by atmospheric distillation and vacuum distillation of crude oil or secondary processing oil, such as heavy diesel oil, heavy gas oil, lubricating oil fraction or cracking raw materials and the like; the residue refers to a bottom distillate obtained by atmospheric and vacuum distillation of crude oil, the atmospheric distillation bottom distillate is generally called atmospheric residue (generally a fraction with a boiling point of more than 350 ℃), the vacuum distillation bottom distillate is generally called vacuum residue (generally a fraction with a boiling point of more than 500 ℃ or 524 ℃), the residue can be at least one selected from topped crude oil, heavy oil obtained from oil sand bitumen and heavy oil with a primary boiling point of more than 350 ℃, and the topped crude oil refers to oil discharged from the bottom of a primary distillation tower or the bottom of a flash tower when the crude oil is fractionated in an atmospheric and vacuum distillation process; the inferior crude oil is thick oil, which refers to crude oil with high content of asphaltene and colloid and high viscosity, and the density of the ground is generally more than 0.943 g/cm at 20 DEG C³The crude oil with the viscosity of the underground crude oil being more than 50 centipoises is called thick oil; the deasphalted oil is rich in asphaltene and rich in aromatic components, which are obtained by contacting, dissolving and separating raw oil with a solvent and at the bottom of an extraction tower in a solvent deasphalting device, and can be divided into propane deasphalted asphalt, butane deoiled asphalt, pentane deoiled asphalt and the like according to the difference of the types of the solvents; the coal derived oil is a liquid fuel obtained by taking coal as a raw material and performing chemical processing, and can be at least one selected from coal liquefied oil generated by coal liquefaction and coal tar generated by coal pyrolysis; shale oil is brown sticky paste obtained by low-temperature dry distillation of oil shale, and has pungent odor and high nitrogen content; the petrochemical waste oil may be selected from the group consisting of petrochemical waste oil sludge, petrochemical oil residue, and refined products thereofAt least one of (1). Other low quality oils known to those skilled in the art may also be used alone or in combination as upgrading materials for the conversion reaction, and the present invention is not further described.

According to the invention, the first separated product generally consists of the product with the highest distillation range in the converted product, which comprises the residue in the step (3), wherein the main component of the residue is asphaltene and also comprises some colloid and aromatic components necessary for maintaining fluidity, the first separated product also comprises the upgraded oil besides the residue, the first separated product can be used as a high-quality raw material for subsequent treatment to obtain other oil products after being separated by extraction, and the rest components with the lower distillation range in the converted product can be separated from the first separated product, such as gas products (such as dry gas, liquefied gas and the like) in a standard state and other components with the distillation range below 350 ℃.

According to the present invention, the separation treatment in step (2) is used to obtain the first separated product having the above-mentioned distillation range composition, and the present invention is not particularly limited to the specific embodiment thereof, and specifically, the separation treatment in step (2) is generally referred to as physical separation, such as extraction, liquid separation, distillation, evaporation, flash evaporation, condensation, and the like.

In one embodiment, in step (2), the separation process includes step (2-1) and step (2-2):

(2-1) separating the conversion product obtained in the step (1) at a first pressure and a first temperature to obtain a gas component and a liquid component; in the step (2-1), gas products such as hydrogen and the like are preferably separated, and the gas components are rich in hydrogen, preferably the hydrogen content is more than 85 weight percent; for example, the first pressure may be in the range of from 10 to 25 MPa, preferably in the range of from 13 to 20 MPa, for convenience of measurement, the first pressure generally referring to the outlet pressure of the gaseous component as it leaves the separation device, the first temperature may be in the range of from 380 ℃ to 470 ℃, preferably in the range of from 400 ℃ to 440 ℃, for convenience of measurement, the first temperature generally referring to the outlet temperature of the liquid component as it leaves the separation device; the way of separation in this step may be distillation, fractionation, flash distillation, etc., preferably distillation, which may be performed in a distillation column, the gas component may be obtained from the top of the distillation column, and the liquid component may be obtained from the bottom of the distillation column;

(2-2) separating the liquid component at a second pressure and a second temperature to obtain the first separated product and a second separated product; in the step (2-2), the components with the distillation range below 350 ℃ are preferably separated, and the components with the distillation range of 350-524 ℃ are kept as much as possible; said first pressure is preferably greater than said second pressure, said first pressure further preferably being 4 to 24 MPa greater than the second pressure, more preferably 7 to 19 MPa greater; in particular, the second pressure may be in the range of from 0.1 to 5 MPa, preferably in the range of from 0.1 to 4 MPa, for convenience of measurement, the second pressure generally referring to the outlet pressure of the second separated product as it leaves the separation device, the second temperature may be in the range of from 150 ℃ to 390 ℃, preferably 200 ℃ to 370 ℃, for convenience of measurement, the second temperature generally referring to the outlet temperature of the first separated product as it leaves the separation device; the separation in this step may be a distillation and/or a fractional distillation, preferably an atmospheric or pressurized fractional distillation, which may be carried out in an atmospheric distillation tank or a pressurized distillation column.

In an alternative embodiment, the separation process further comprises step (2-3) and/or step (2-4):

(2-3) subjecting the second separated product obtained in the step (2-2) to a cleavage to obtain naphtha and atmospheric gas oil, the cleavage being carried out by fractionation or distillation, preferably fractionation, for example, in a fractionating column, which may be operated at a pressure of 0.05 to 2.0 MPa, preferably 0.1 to 1.0 MPa, and at a temperature of 50 to 350 ℃, preferably 150 to 330 ℃; and/or

(2-4) returning the gas component obtained in the step (2-1) to the step (1) for conversion reaction, wherein the gas component can be directly used or separated to be used as recycle hydrogen.

According to the present invention, the extraction separation is used for separating the easily processable modified oil in the first separation product, and the residue is thrown outwards or returned to the conversion reaction, specifically, in the step (3), the extraction separation can be performed in the extraction solvent at the third temperature and the third pressure, preferably, the extraction solvent is extracted by countercurrent contact with the first separation product, and can be performed in any extraction device, such as an extraction tower; wherein the third pressure may be 3 to 12 MPa, preferably 3.5 to 10 MPa, the third pressure beingThe temperature can be 55-300 deg.C, preferably 70-220 deg.C, and the extraction solvent can be C₃-C₇A hydrocarbon, preferably C₃-C₅Alkane and C₃-C₅At least one of olefins, more preferably C₃-C₄Alkane and C₃-C₄At least one olefin, the weight ratio of the extraction solvent to the first separation product being (1-7): 1, preferably (1.5-5): 1. other conventional extraction methods can be adopted by the person skilled in the art for extraction, and the description of the invention is omitted.

According to the invention, the residue is the highest boiling component of the conversion product, the more completely the easily processable component of the conversion product is separated the higher its softening point, but in order to maintain the fluidity of the residue on line transport and solubility on return to the conversion reactor, the softening point of said residue is preferably less than 150 ℃, more preferably less than 120 ℃ in step (3).

According to the present invention, if the conversion reaction of the present invention is carried out in a fluidized bed reactor, the conversion catalyst therein is subsequently separated along with the conversion product and remains in the residue, and the metal in the entire upgrading system is increased as the amount of the catalyst added increases and as the metal component in the upgrading raw material accumulates. In order to maintain the balance of metals in the upgrading system, the residue needs to be discharged intermittently or continuously, and in order to fully use the upgrading raw material, part of the residue is thrown outwards in the step (4), and the thrown-out residue accounts for less than 10 wt% of the upgrading raw material; the proportion of residue returned to step (1) is preferably greater than 80% by weight, preferably greater than 90% by weight, more preferably greater than 95% by weight. The proportion of the slag thrown out can be adjusted by those skilled in the art according to the modified raw materials with different metal contents, and the invention is not described in detail.

As shown in fig. 1, the present invention also provides a low quality oil upgrading system, which comprises a conversion reactor 7, a separation treatment unit and an extraction separation unit 16; the conversion reactor 7 is provided with a reaction material inlet (the reaction material comprises a modified raw material, hydrogen and residue, and may or may not comprise a modified catalyst) and a converted product outlet, the separation processing unit is provided with a processed raw material inlet and a first separated product outlet, and the extraction separation unit 16 is provided with an extraction solvent inlet, an extraction raw material inlet, a modified oil outlet and a residue outlet; the conversion product outlet of the conversion reactor 7 is communicated with the treated raw material inlet of the separation treatment unit, the first separation product outlet of the separation treatment unit is communicated with the extracted raw material inlet of the extraction separation unit 16, and the residue outlet of the extraction separation unit 16 is optionally connected with the reaction material inlet of the conversion reactor 7.

The system provided by the invention is used for carrying out the upgrading reaction provided by the invention, for example, as shown in fig. 1, the separation processing unit comprises a high-pressure separation unit 9 and a low-pressure separation unit 13, the high-pressure separation unit 9 is provided with a gas component outlet, a liquid component outlet and the processing raw material inlet, the low-pressure separation unit 13 is provided with a low-pressure raw material inlet, a second separation product outlet and the first separation product outlet, and the liquid component outlet of the high-pressure separation unit 9 is communicated with the low-pressure raw material inlet of the low-pressure separation unit 13. The high pressure separation unit and the low pressure separation unit may both be distillation units or fractionation units, such as distillation columns and the like, which are distinguished by an operating pressure, the high pressure separation unit being operated at a higher pressure than the low pressure separation unit.

According to the invention, the gas component outlet of the high-pressure separation unit 9 is connected to the reaction mass inlet of the conversion reactor 7, as shown in fig. 1, in order to recycle the gas components.

The invention will be further illustrated by the following specific embodiments, but the invention is not limited thereto.

As shown in fig. 1, the reforming raw material is fed to a reforming reactor 7 through a line 1, a reforming catalyst through a line 2, a recycle hydrogen through a line 3, a fresh hydrogen through a line 4, and a residue through a line 5 to undergo reforming reaction. The converted product is conveyed to a high-pressure separation unit 9 through a pipeline 8 for pressure distillation, separated into a gas component and a liquid component, and then the gas component is taken as circulating hydrogen and conveyed to a conversion reactor 7 through a pipeline 10, a pipeline 3 and a pipeline 6 in sequence, or is led out of the upgrading system through a pipeline 10 and a pipeline 11 in sequence. The liquid component is conveyed via line 12 to a low pressure separation unit 13 for pressure letdown and separation into a second separated product and a first separated product. The second separated product is led out of the upgrading system through a pipeline 15, and the first separated product is conveyed to an extraction separation unit 16 through a pipeline 14 to be in countercurrent contact with an extraction solvent from a pipeline 17 for extraction separation, so that upgraded oil and residues are obtained. The modified oil is led out of the modifying system through a pipeline 18, one part of the residue is thrown out through a pipeline 19 and a pipeline 20, and the rest part of the residue is used as a modified raw material and is circulated to the conversion reactor 7 through the pipeline 19, the pipeline 5 and the pipeline 6 to be subjected to conversion reaction with the modified raw material continuously. Alternatively, all the residues may be thrown out through the line 19 and the line 20 one after another without being circulated.

The present invention will be described in further detail with reference to examples, but the present invention is not limited to these examples.

In the context of the present invention and included in the following examples and comparative examples:

the content of heavy metals (calculated by the total weight of nickel and vanadium) in the oil product is determined according to ASTM D5708;

the method for measuring the content of the asphaltene in the oil product is carried out according to SH/T0266-92 (1998);

the conversion of the modified raw material is (1-removal rate of the residue) x 100 wt%, and the removal rate of the residue is (weight of the removed residue/weight of the modified raw material x 100 wt%;

yield of upgraded oil is upgraded oil weight/upgraded raw material weight × 100%;

yield of toluene insoluble matter in the upgraded oil is toluene insoluble matter weight/upgraded oil weight × 100%;

the softening point of the residue is measured by a GB/T4507-84 method;

the special component refers to the component with the distillation range between 350 ℃ and 524 ℃ in the first separation product.

The operation stability of the reforming process was evaluated by the number of days of stable operation of the reforming system. Specifically, the upgrading system is determined to be unable to operate stably if any one of the following conditions occurs:

(1) the maximum temperature difference delta T (absolute value) of different temperature measuring points in the conversion reactor is more than 5 ℃; (2) the upgraded oil appears black, which normally appears yellow or yellowish green.

The following examples and comparative examples were modified according to the embodiment shown in FIG. 1.

In the following examples and comparative examples, as the upgraded raw materials, upgraded raw material a and upgraded raw material B were vacuum residuum, upgraded raw material C was venezuelan heavy oil reduced residuum, upgraded raw material D was high temperature coal tar, and upgraded raw material E was deoiled asphalt, and properties of these five upgraded raw materials are shown in table 1.

Examples 1 to 5

On a medium-sized apparatus, first, a reforming reaction is carried out on a reforming raw material, and then a separation treatment of the reformed product is carried out in two fractionation columns to obtain a first separated product and a second separated product, and specific conditions and results of the reforming reaction and the separation treatment are shown in table 2.

Examples 6 to 8

On a medium-sized apparatus, the reforming raw material was first subjected to a conversion reaction and then to a separation treatment carried out in two fractionation columns to obtain a first separated product and a second separated product, and specific conditions and results of the conversion reaction and the separation treatment are shown in Table 3.

Examples 9 to 11

The first separated products obtained in example 2, example 4 and example 7 were subjected to extractive separation on a medium-sized apparatus, and specific conditions and results of the extractive separation are shown in Table 4.

Examples 12 to 13

On a medium-sized device, a conversion reaction is carried out by taking a modified raw material B and a modified raw material C as raw materials, and then separation treatment is carried out, wherein the separation treatment is carried out in two fractionating towers to obtain a first separation product and a second separation product. And extracting and separating the first separation product to obtain modified oil and residue. One part of the residue circulates, and the other part is thrown outwards. And respectively mixing the recycled residues with the modified raw material B and the modified raw material C, carrying out conversion reaction, and then sequentially carrying out separation treatment and extraction separation to obtain modified oil and residues. And separating the obtained second separation product to obtain naphtha fraction and normal pressure gas oil. The specific conditions and results of the respective steps are shown in tables 5-1 and 5-2.

Comparing the results in tables 4, 5-1 and 5-2, it is clear that recycling the residue is advantageous in improving the conversion of the upgraded raw material and the yield of the upgraded oil.

Example 14

On a medium-sized device, the modified raw material B is used as the modified raw material to carry out conversion reaction, and then separation treatment is carried out, wherein the separation treatment is carried out in two fractionating towers to obtain a first separation product and a second separation product. The first separated product was further subjected to extraction separation (extraction separation conditions were the same as in example 12) to obtain an upgraded oil and a residue. And taking part of the residues as circulating materials, mixing the circulating materials with the fresh modified raw material B, carrying out conversion reaction, and throwing the rest of the residues outwards. The conversion products of the mixed raw materials were separated in two fractionation columns in order, and subjected to extraction separation (the extraction separation conditions were the same as in example 12) to obtain an upgraded oil and a residue. And simultaneously separating the obtained second separation product to obtain naphtha fraction and normal-pressure gas oil. The specific conditions and results of the respective steps are shown in tables 6-1 and 6-2.

Comparative examples 1 to 4

The basic procedure was the same as in example 14 except that the conditions for the extraction and separation were changed as shown in Table 7-1, and the same conditions were used as in example 12.

The results in Table 7-2 show that when one of the conversion rate of the conversion reaction, the component content of the first separated product less than 350 ℃ and the specific component content does not meet the corresponding requirements of the invention, the conversion rate of the modified raw material is reduced by 6-12 percent, the yield of the modified oil is reduced by 5-16 percent, the yield of the toluene insoluble substance is improved by 1-4.5 percent, and the stable operation days of the modified system are greatly reduced because the delta T is more than 5 ℃ or the modified oil is black.

TABLE 1

TABLE 2

TABLE 3

TABLE 4

TABLE 5-1

TABLE 5-2

TABLE 6-1

Item	Example 14
		Modified raw material	Modified raw material B + residue
Source of residue	By itself (example 14)
		Conversion reaction
Reaction temperature/. degree.C	425
		Reaction pressure/MPa	18
Conversion catalyst	Ammonium molybdate
		Volumetric space velocity/hour^-1	0.15
Catalyst loading/(microgram/gram)	1000
		Partial pressure of hydrogen/MPa	17.4
Volume ratio of hydrogen to upgrading feedstock	1300
		Treatment of the conversion products
First pressure/MPa	18
		First temperature/. degree.C	410
Second pressure/MPa	1.5
		Second temperature/. degree.C	320

TABLE 6-2

Item	Example 14
		Conversion/% of the conversion reaction	55.3
Product distribution/weight%
		First separated product	67.7
Distillation range/. degree.C.of particular components in the first separation product	350-524
		Content/weight% of particular component in first separated product	34
The distillation range of the first separated product is less than 350 ℃ component content/weight%	3
		End point of the second separation product/. degree.C.	324
Modified result
		Conversion of modified feedstock/%	92.6
Yield of upgraded oil/%	86.4
		Heavy metal content/weight (microgram/gram) of modified oil	<1
Modified oil asphaltene content/weight%	<0.1
		Yield of toluene insolubles/weight%	0.9
Number of days of Stable operation	>30 days

TABLE 7-1

TABLE 7-2

Claims

1. A process for upgrading low quality oil, the process comprising:

(1) carrying out conversion reaction on low-quality oil serving as a modified raw material in a conversion reactor under a hydrogen condition to obtain a conversion product; wherein the upgraded feedstock comprises at least one bituminous component selected from the group consisting of asphaltenes, asphaltenes and preasphaltenes, the conversion of the conversion reaction is from 30 to 60 wt%, the conversion of the conversion reaction being (weight of components in the upgraded feedstock having a distillation range above 524 ℃ C. — weight of components in the converted product having a distillation range above 524 ℃ C.)/weight of components in the upgraded feedstock having a distillation range above 524 ℃ x 100 wt%;

2. The upgrading process of claim 1, in step (1), the conversion reactor is a fluidized bed reactor;

the conversion reaction is carried out in the presence or absence of a conversion catalyst containing at least one selected from the group consisting of group VB metal compounds, group VIB metal compounds and group VIII metal compounds;

the conversion reaction conditions include: the temperature is 380-470 ℃, the hydrogen partial pressure is 10-25 MPa, and the volume space velocity of the modified raw material is 0.01-2 hours^-1The volume ratio of the hydrogen to the modified raw material is 500-5000, and the amount of the conversion catalyst is 10-50000 micrograms/g based on the weight of the modified raw material and calculated by the metal in the conversion catalyst.

3. The upgrading method of claim 1, in step (1), the upgraded feedstock comprising at least one selected from the group consisting of poor crude oil, heavy oil, deoiled bitumen, coal derived oil, shale oil, and petrochemical waste oil.

4. The upgrading process of claim 1, the upgrading feedstock meeting one or more criteria selected from the group consisting of an API degree of less than 27, a distillation range of greater than 350 ℃, a bitumen component content of greater than 2 wt.%, and a heavy metal content of greater than 100 micrograms/gram, based on the total weight of nickel and vanadium.

5. The upgrading method as claimed in claim 1, wherein in step (2), the content of components with distillation range below 350 ℃ in the first separated product is less than 3 wt%, and the content of components with distillation range between 350 ℃ and 524 ℃ is 25-55 wt%.

6. The upgrading method according to claim 1, wherein in step (2), the separation process comprises:

(2-1) separating the conversion product obtained in the step (1) at a first pressure and a first temperature to obtain a gas component and a liquid component;

(2-2) separating the liquid component at a second pressure and a second temperature to obtain the first separated product and a second separated product; wherein the first pressure is greater than the second pressure.

7. The upgrading process of claim 6, wherein the first pressure is 4-24 megapascals greater than the second pressure.

8. The upgrading method of claim 6, wherein the first pressure is 10-25 MPa and the first temperature is 380-470 ℃; the second pressure is 0.1-5 MPa, and the second temperature is 150-390 ℃.

9. The upgrading method according to claim 6, wherein the separation process further comprises:

(2-3) cutting the second separation product obtained in the step (2-2) to obtain naphtha and atmospheric gas oil; and/or

(2-4) returning the gas component obtained in the step (2-1) to the step (1) for conversion reaction.

10. The upgrading process of claim 1, in step (3), the extractive separation is carried out in an extraction solvent at a third temperature and a third pressure; wherein the third pressure is 3-12 MPa, the third temperature is 55-300 deg.C, and the extraction solvent is C₃-C₇A hydrocarbon, the weight ratio of the extraction solvent to the first separation product being (1-7): 1.

11. the upgrading method of claim 1, in step (3), the softening point of the residue is less than 150 ℃.

12. The upgrading method according to claim 1, wherein in step (4), the proportion of the residue returned to step (1) is greater than 80% by weight.

13. The upgrading method of claim 1, wherein in step (4), a portion of the tailings is sluiced out, and the sluiced out tailings account for less than 10 wt.% of the upgrading feedstock.

14. A system for implementing the low quality oil upgrading process of claim 1, the system comprising a conversion reactor (7), a separation treatment unit and an extractive separation unit (16);

the conversion reactor (7) is provided with a reaction material inlet and a conversion product outlet, the separation processing unit is provided with a processing raw material inlet and a first separation product outlet, and the extraction separation unit (16) is provided with an extraction solvent inlet, an extraction raw material inlet, a modified oil outlet and a residue outlet;

the conversion product outlet of the conversion reactor (7) is communicated with the processing raw material inlet of the separation processing unit, the first separation product outlet of the separation processing unit is communicated with the extraction raw material inlet of the extraction separation unit (16), and the residue outlet of the extraction separation unit (16) is optionally connected with the reaction material inlet of the conversion reactor (7).

15. A system according to claim 14, wherein the separation process unit comprises a high pressure separation unit (9) and a low pressure separation unit (13), the high pressure separation unit (9) being provided with a gaseous component outlet, a liquid component outlet and the process feed inlet, the low pressure separation unit (13) being provided with a low pressure feed inlet, a second separation product outlet and the first separation product outlet, the liquid component outlet of the high pressure separation unit (9) being in communication with the feed inlet of the low pressure separation unit (13).