CN114437814B

CN114437814B - Hydrogenation method and hydrogenation purification system for catalytic cracking tower bottom oil and method for producing low-sulfur marine fuel oil

Info

Publication number: CN114437814B
Application number: CN202011119267.4A
Authority: CN
Inventors: 邵志才; 邓中活; 戴立顺; 胡志海; 牛传峰; 刘涛; 施瑢; 聂鑫鹏; 任亮; 方强; 张奎; 胡大为; 韩伟
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: 2020-10-19
Filing date: 2020-10-19
Publication date: 2023-08-08
Anticipated expiration: 2040-10-19
Also published as: CN114437814A

Abstract

The invention relates to the field of hydrocarbon oil processing, and disclosesA hydrogenation method of catalytic cracking tower bottom oil, a hydrogenation purification system and a method for producing low-sulfur marine fuel oil are provided; the mixture contains the kinematic viscosity at 100 ℃ which is less than or equal to 32mm ² Introducing raw oil of catalytic cracking tower bottom oil and hydrogen-containing gas into a low-pressure hydrogenation reaction zone and a gas-liquid separation zone in sequence to obtain a gas-phase material flow and a liquid-phase material flow; mixing the liquid phase material flow with a blending component to obtain low-sulfur marine fuel oil; the hydrogenation purification system comprises a low-pressure hydrogenation reaction unit and a gas-liquid separation unit, wherein a raw material feed line of the hydrogenation purification system is communicated with an inlet of the low-pressure hydrogenation reaction unit, and an outlet of the hydrogenation purification system is communicated with an outlet of the gas-liquid separation unit. The invention can remove most of asphaltene and solid particles in the catalytic cracking tower bottom oil, can ensure long-period operation of subsequent devices, and has the characteristics of low cost, long operation period, good environmental protection, high value and the like.

Description

Hydrogenation method and hydrogenation purification system for catalytic cracking tower bottom oil and method for producing low-sulfur marine fuel oil

Technical Field

The invention relates to the field of hydrocarbon oil processing, in particular to a hydrogenation method and a hydrogenation purification system for catalytic cracking tower bottom oil and a method for producing low-sulfur marine fuel oil.

Background

Catalytic cracking is an important process technology for producing gasoline and diesel oil by lightening heavy oil, and is one of the most important and most widely applied technologies in the oil refining field at present. The slurry oil is a low added value product at the bottom of the catalytic cracking main fractionating tower, has high content of polycyclic aromatic hydrocarbon and colloid, and is difficult to crack in the recycling process of the catalytic cracking main fractionating tower, and Yi Shengjiao, so that a part of slurry oil is required to be thrown outside a catalytic cracking device, but the further utilization value of the slurry oil is influenced due to the high content of solid particles (more than 2 g/L).

With the continuous aggravation of global environmental problems, environmental regulations are continuously put out at home and abroad to limit the sulfur content of marine fuel oil (hereinafter referred to as ship combustion). The low-sulfur heavy ship fuel can be produced by utilizing low-sulfur residual oil or hydrogenated residual oil, but the production cost is higher, and the low-cost blending component needs to be searched, so that the production cost of the low-sulfur ship fuel oil is reduced.

The existing catalytic slurry purification technology mainly comprises the following steps:

1. natural sedimentation method. The advantages are that: the equipment is simple and easy to operate; disadvantages: long separation time, high investment cost, difficult removal of catalyst particles with the particle size smaller than 50um and poor purification effect.

2. And (5) filtering. The advantages are that: the operation is simple, and the short-term separation efficiency is high; disadvantages: the filter resistance is large, the flushing time is long, micron-sized particles are difficult to remove, and the filter element is easy to damage and difficult to regenerate.

3. Electrostatic separation. The advantages are that: the washing is easy, the finer the particles are, the easier the particles are to adsorb, and the resistance is small; disadvantages: the process is complex, the equipment investment is large, and the separation efficiency is low.

4. And (3) a centrifugal separation method. The advantages are that: the device has simple structure and small volume. Disadvantages: the separation efficiency is not high, the operation is inconvenient, and the maintenance is difficult.

5. And (5) an auxiliary agent sedimentation method. The advantages are that: the equipment is simple and the operation is convenient. Disadvantages: the separation effect is unstable.

At present, no method for efficiently purifying the oil slurry exists, the content of solid particles in the purified oil slurry is still higher (higher than 300 ppm), and the operation of the existing built purifying device is unstable and idle.

CN104119952a provides a method for hydrotreating hydrocarbon oil, in which hydrocarbon oil and hydrogen are contacted with a plurality of hydrogenation catalyst beds in a hydrotreating apparatus; the main and standby hydrotreating reactors may be used alternately. The method has the advantages that the effect is not obvious when the catalytic slurry oil with larger viscosity is treated, the content of solid particles cannot be effectively removed, and meanwhile, the purification of the slurry oil can be influenced by the height-diameter ratio of the reactor.

CN103013567a is a process for producing needle coke from catalytic slurry oil, which is provided with a protection zone and a hydrogenation reaction zone, wherein the catalytic slurry oil firstly enters the protection zone to adsorb most of catalytic cracking catalyst powder, then is mixed with hydrogen into a heating furnace, and enters the hydrogenation reaction zone for hydrogenation treatment reaction after heating. The protection reactor is filled with large-particle honeycomb adsorbent, so that the removal effect of solid particles in the slurry oil is poor, and the solid particles deposited on the surface of the adsorbent cannot be effectively intercepted.

Disclosure of Invention

The invention aims to solve the problems that the existing oil slurry is large in solid particle quantity after purification, and the operation of a purification device is unstable.

The inventor of the invention researches and discovers that the content of asphaltene and colloid in the catalytic cracking tower bottom oil is higher, solid particles in the catalytic cracking tower bottom oil are "wrapped" in the colloid structure of asphaltene and colloid, and after the colloid structure is destroyed under the hydrogenation reaction condition, the solid particles in the catalytic cracking tower bottom oil are adsorbed on the surface of an adsorbent and in a pore canal, so that the solid particles in the catalytic cracking tower bottom oil can be removed.

The inventor of the present invention also found that the viscosity of the catalytic cracking bottom oil produced by different catalytic cracking units is different; the stability of the colloid structures of asphaltene and colloid in different catalytic cracking tower bottoms is different, the more stable the structure is, the more difficult solid particles in the catalytic cracking tower bottoms are adsorbed on a hydrogenation adsorbent, and further research shows that the viscosity of the catalytic cracking tower bottoms is relatively higher than the colloid stability of the structure, and the kinematic viscosity (100 ℃) of the catalytic cracking tower bottoms is 32mm ² And below/s, wherein the solid particles can be effectively adsorbed on the hydrogenation adsorbent.

Based on the above findings, the present invention has been completed.

In order to achieve the above object, a first aspect of the present invention provides a hydrogenation method of a catalytic cracking bottom oil, the method comprising:

(1) Introducing raw oil containing catalytic cracking tower bottom oil and hydrogen-containing gas into a low-pressure hydrogenation reaction zone with the operating pressure not higher than 10.0MPa for contact reaction to obtain a reaction product I, wherein the kinematic viscosity of the catalytic cracking tower bottom oil at 100 ℃ is less than or equal to 32mm ² At least one fixed bed reactor filled with adsorbent is arranged in the low-pressure hydrogenation reaction zone, at least one hydrogenation protecting adsorbent and at least one hydrogenation function adsorbent are graded in the fixed bed reactor in sequence according to the flow direction of materials in the fixed bed reactor, and the hydrogenation function adsorbent is hydrodemetallization adsorbent and/or hydrodesulphurization adsorbent;

(2) And introducing the reaction product I into a gas-liquid separation zone for separation to obtain a gas-phase material flow and a liquid-phase material flow.

In a second aspect, the present invention provides a method of producing low sulfur marine fuel oil, the method comprising:

(i) Hydrotreating the catalytic cracking bottoms by the method of the first aspect to obtain a liquid stream as described in step (2);

(ii) And mixing the liquid phase material flow with a blending component to obtain the low-sulfur marine fuel oil.

A third aspect of the present invention provides a hydrogenation purification system for a catalytic cracking bottoms oil, the hydrogenation purification system comprising a low pressure hydrogenation reaction unit and a gas-liquid separation unit, the operating pressure in the low pressure hydrogenation reaction unit being no higher than 10.0MPa, the gas-liquid separation unit having a gas phase stream outlet and a liquid phase stream outlet, a feedstock feed line of the hydrogenation purification system being in communication with an inlet of the low pressure hydrogenation reaction unit, an outlet of the hydrogenation purification system being in communication with an outlet of the gas-liquid separation unit;

optionally, a main fractionating tower capable of fractionating the raw oil entering the hydrogenation purification system is further arranged upstream of the low-pressure hydrogenation reaction unit of the hydrogenation purification system.

The catalytic cracking tower bottom oil hydrogenation purification system provided by the invention can remove most of solid particles in the catalytic cracking tower bottom oil raw material, provides relatively good raw materials for the treatment of a subsequent device, and can ensure the long-period operation of the subsequent device, thereby increasing the operation efficiency of the subsequent device and improving the economical efficiency.

Compared with the prior art, the method provided by the invention has the main advantages that:

(1) The invention breaks colloid and asphaltene colloid groups under lower pressure, lower hydrogen-oil ratio and lower temperature by controlling the viscosity of the bottom oil of the catalytic cracking main fractionation tower, and utilizes a hydrogenation adsorbent to adsorb solid particles in the bottom oil of the main fractionation tower, and preferably, the invention adopts a low-quality hydrogen source with lower hydrogen volume fraction;

(2) The hydrogenation reaction zone in the invention can not only remove solid particles in the bottom oil of the main fractionating tower, but also remove asphaltene, increase the hydrogen content of the bottom oil of the main fractionating tower and reduce the sulfur content of the bottom oil of the main fractionating tower;

(3) The method of the invention utilizes the whole fraction of the catalytic cracking tower bottom oil, and reduces the production cost of the low-sulfur marine fuel oil.

Drawings

FIG. 1 is a schematic illustration of the hydrogenation process flow of a catalytic cracking bottoms oil in accordance with a preferred embodiment of the present invention.

Description of the reference numerals

1. A catalytic cracking reaction product line;

2. a main fractionating tower;

3. an overhead gas stream outlet;

4. a naphtha stream outlet;

5. a diesel stream outlet;

6. a raw material feed line;

7. a low pressure hydrogenation reaction unit;

8. an outlet line of the low pressure hydrogenation reaction unit;

9. a gas-liquid separation unit;

10. a vapor stream outlet line;

11. a liquid phase stream outlet line;

12. a hydrogen-containing gas feed line;

13. a blending unit;

14. a blending component feed line;

15. low sulfur marine fuel oil outlet line.

Detailed Description

The endpoints and any values of the ranges disclosed herein are not limited to the precise range or value, and are understood to encompass values approaching those ranges or values. For numerical ranges, one or more new numerical ranges may be found between the endpoints of each range, between the endpoint of each range and the individual point value, and between the individual point value, in combination with each other, and are to be considered as specifically disclosed herein.

As previously described, a first aspect of the present invention provides a process for the hydrogenation of a catalytic cracking bottoms, the process comprising:

(1) Will contain the bottom of the catalytic cracking towerIntroducing the raw oil of the oil and hydrogen-containing gas into a low-pressure hydrogenation reaction zone with the operating pressure not higher than 10.0MPa for contact reaction to obtain a reaction product I, wherein the kinematic viscosity of the catalytic cracking tower bottom oil at 100 ℃ is less than or equal to 32mm ² At least one fixed bed reactor filled with adsorbent is arranged in the low-pressure hydrogenation reaction zone, at least one hydrogenation protecting adsorbent and at least one hydrogenation function adsorbent are graded in the fixed bed reactor in sequence according to the flow direction of materials in the fixed bed reactor, and the hydrogenation function adsorbent is hydrodemetallization adsorbent and/or hydrodesulphurization adsorbent;

Preferably, the raw oil containing the catalytic cracking tower bottom oil and hydrogen-containing gas are introduced into a low-pressure hydrogenation reaction zone with the operating pressure not higher than 8.0MPa for contact reaction, so as to obtain a reaction product I.

According to a preferred embodiment, in the step (1), the raw oil does not contain diluent oil.

According to another particularly preferred embodiment, in the step (1), the raw oil further contains a diluent oil, and the mass ratio of the diluent oil to the catalytic cracking bottom oil is 0.05-4:1.

preferably, the diluent oil is at least one selected from catalytic diesel oil, catalytic cracking cycle oil, coal tar and ethylene tar.

Preferably, the diluent oil has a density (20 ℃) of 0.5 to 2.0g/cm ³ Viscosity (100deg.C) of 2-10mm ² Sulfur content is 0.2-1.8 wt%, and solid particle content is 50-300 mug/g.

Preferably, the density (20 ℃) of the catalytic cracking bottom oil is 0.6-3.0g/cm ³ Viscosity (100deg.C) of 10-80mm ² And/s, sulfur content is 0.2-3 wt%, asphaltene content is 1-20 wt% and solid particle content is 1000-5000 mug/g.

Preferably, the overall height-to-diameter ratio of each of the fixed bed reactors provided in the low pressure hydrogenation reaction zone is 5 to 10 independently, the overall height-to-diameter ratio being a ratio of a tangential height of the fixed bed reactor to an inner diameter of the fixed bed reactor, the tangential height and the inner diameter being the same in units.

Preferably, the conditions of the low pressure hydrogenation reaction zone are at least: the hydrogen partial pressure is 0.1 MPa-5.0 MPa, the reaction temperature is 100-400 ℃, and the liquid hourly space velocity is 0.10-1.0 h ^-1 The volume ratio of the hydrogen oil is 10 to 500.

More preferably, the conditions of the low pressure hydrogenation reaction zone at least satisfy: the reaction temperature is 280-380 ℃, and the liquid hourly space velocity is 0.2-0.5 h ^-1 The volume ratio of the hydrogen oil is 50-300.

Preferably, the pressure of the gas-liquid separation zone in step (2) is the same as the pressure of the low pressure hydrogenation reaction zone in step (1).

Preferably, in each fixed bed reactor of the low pressure hydrogenation reaction zone, the loading of the hydrogenation protecting adsorbent is 1 to 95% by volume and the loading of the hydrogenation functional adsorbent is 5 to 99% by volume based on the total volume of the loaded adsorbent.

Preferably, in each of the fixed bed reactors of the low pressure hydrogenation reaction zone, each of the adsorbents independently contains a carrier and an active ingredient supported on the carrier, the carriers are each independently selected from at least one of alumina, silica and titania, and the active ingredients are each independently selected from at least one of a group VIB metal element and/or a group VIII metal element.

Preferably, in the hydrogenation protecting adsorbent, the content of the active component in terms of oxide in the hydrogenation protecting adsorbent is 0-15 wt% and the content of the carrier is 85-100 wt% based on the mass of the hydrogenation protecting adsorbent.

Preferably, in the hydrodemetallization adsorbent, the content of the active component in terms of oxide in the hydrodemetallization adsorbent is 1-25 wt% and the content of the carrier is 75-99 wt%, based on the mass of the hydrodemetallization adsorbent.

Preferably, in the hydrodesulfurization adsorbent, the content of the active component in terms of oxide in the hydrodesulfurization adsorbent is 1 to 25 wt% and the content of the carrier is 75 to 99 wt% based on the mass of the hydrodesulfurization adsorbent.

Preferably, the average particle diameter of the hydrogenation protecting adsorbent is 0.5-50.0 mm, and the bulk density is 0.3-1.2 g/cm ³ A specific surface area of 50 to 300m ² /g。

More preferably, the average particle diameter of the hydrogenation protecting adsorbent is 0.5-5.0 mm

Preferably, the average grain diameter of the hydrogenation function adsorbent is 0.2-3.0 mm, and the bulk density is 0.3-0.8 g/cm ³ Specific surface area of 100-250 m ² /g。

Preferably, the initial boiling point of the catalytic cracking tower bottom oil is 180-530 ℃, preferably 280-430 ℃.

Preferably, the process further comprises obtaining said catalytic cracking bottoms by a process comprising the steps of:

introducing the catalytic cracking reaction product into a main fractionating tower for fractionating to obtain catalytic gasoline, catalytic diesel oil and the catalytic cracking tower bottom oil.

Preferably, the catalytic cracking reaction product is selected from products obtained from at least one of a conventional catalytic cracking process, DCC process, MIP process, HSCC process, MIP-CGP process.

The DCC process is a catalytic cracking process; the MIP process is a catalytic cracking process for producing isoparaffin in a more yield; the HSCC process is a selective catalytic cracking process; the MIP-CGP technology is the catalytic cracking technology of clean gasoline for increasing the yield of propylene and producing more isomerized alkane.

Preferably, the hydrogen content in the hydrogen-containing gas in the step (1) is 20 to 100% by volume.

Preferably, the hydrogen-containing gas is selected from at least one of hydrogen, catalytic cracking dry gas, coking dry gas, hydrogenation unit low-pressure gas or reformed hydrogen.

According to a preferred embodiment, the hydrogen-containing gas is formed by mixing hydrogen, methane, ethane and propane, and the hydrogen content in the hydrogen-containing gas is not less than 20% by volume.

Preferably, a fixed bed reactor is disposed in the low pressure hydrogenation reaction zone.

It should be noted that, in the present invention, the fixed bed reactor disposed in the low pressure hydrogenation reaction zone is optionally a downflow reactor or an upflow reactor, where the upflow reactor refers to a reactor in which a stream flows from bottom to top, and the downflow reactor refers to a reactor in which a stream flows from top to bottom.

As described above, the second invention of the present invention provides a method for producing low sulfur marine fuel oil, the method comprising:

(i) Hydrotreating the catalytic cracking bottoms by the method of the first aspect to obtain the liquid phase stream of step (2) of the first aspect;

Preferably, the blending component is at least one selected from the group consisting of atmospheric residuum, vacuum residuum, catalytic diesel, straight run wax oil, hydrogenated residuum, low sulfur diesel.

Preferably, the blend component has a density (20 ℃) of from 0.2 to 1.5g/cm ³ Viscosity (100deg.C) of 10-40mm ² Viscosity (50 ℃) of 0.5-1000mm ² And/s, sulfur content is 0.01-1.5 wt%.

Preferably, the weight ratio of the liquid phase stream to the total weight of each of the blending components is 5:95 to 40:60, more preferably 10:90 to 35:65.

as described above, the third aspect of the present invention provides a hydrogenation purification system for a catalytic cracking bottom oil, the hydrogenation purification system comprising a low pressure hydrogenation reaction unit and a gas-liquid separation unit, the operating pressure in the low pressure hydrogenation reaction unit being not higher than 10.0MPa, the gas-liquid separation unit having a gas phase stream outlet and a liquid phase stream outlet, a feedstock feed line of the hydrogenation purification system being in communication with an inlet of the low pressure hydrogenation reaction unit, an outlet of the hydrogenation purification system being in communication with an outlet of the gas-liquid separation unit;

Preferably, a blending unit for mixing the liquid-phase stream with blending components is further arranged downstream of the gas-liquid separation unit of the hydrogenation purification system.

According to a particularly preferred embodiment, the method according to the invention is carried out using the process flow shown in fig. 1, in particular:

(1) Sending the catalytic cracking reaction product into a main fractionating tower 2 through a catalytic cracking reaction product line 1 for fractionation to obtain catalytic gasoline, catalytic diesel oil, catalytic cracking tower bottom oil and tower top gas; the catalytic gasoline flows out through a crude gasoline stream outlet 4, the catalytic diesel flows out through a diesel stream outlet 5, and the overhead gas flows out through an overhead gas stream outlet 3; the bottom oil of the catalytic cracking tower is mixed with hydrogen-containing gas from a hydrogen-containing gas feeding line 12 through a raw material feeding line 6 and enters a low-pressure hydrogenation reaction unit 7 to obtain a reaction product I;

(2) Introducing the reaction product I into a gas-liquid separation unit 9 through a low-pressure hydrogenation reaction unit outlet pipeline 8 for separation to obtain a gas-phase material flow and a liquid-phase material flow, wherein the gas-phase material flow flows out through a gas-phase material flow outlet pipeline 10;

(3) The liquid phase stream enters blending unit 13 via liquid phase stream outlet line 11 and is blended with a blending combination from blending component feed line 14 to produce a low sulfur marine fuel oil which exits via low sulfur marine fuel oil outlet line 15.

In the invention, the hydrogenation protecting adsorbent and the hydrogenation function adsorbent have the functions of adsorbing solid particles and catalyzing hydrogenation.

It should be noted that the selection of the downstream device of the gas-liquid separation unit of the hydrogenation purification system is not particularly limited in the present invention, and the catalyst gradation and the process conditions of the downstream device may be set accordingly according to the nature of the raw material and the nature of the product, and one downstream device is provided in the present invention by way of example, and those skilled in the art should not understand the limitation of the present invention.

Unless otherwise indicated, the pressures described herein are gauge pressures.

The invention will be described in detail below by way of examples. In the examples below, various raw materials used were available from commercial sources without particular explanation.

The properties of the raw oils used in the examples below are shown in Table 1, and the properties of the blending combinations are shown in Table 2.

The hydrogenation adsorbents used in the examples below were developed by the institute of petrochemical and petrochemical industries and were produced by the catalyst longline division.

In the following examples RGX series are the hydroprotected adsorbents, RMX series are the hydrodemetallated adsorbents, and RSX series are the hydrodesulphurised adsorbents.

Hydrogenation protection adsorbent: the brand is RGX-30B, and the average grain diameter is 3mm;

hydrodemetallization adsorbent: the brand is RMX-35, and the average grain diameter is 1.3mm;

hydrodesulfurization adsorbent: the brand is RSX-3, and the average grain diameter is 1.3mm.

The hydrogen-containing gas used in the following examples was formed of a mixed gas of 50% by volume of hydrogen, 24% by volume of methane, 11% by volume of ethane, 4% by volume of propane, and 11% by volume of the remaining gas.

In the following examples, a single downflow bed type fixed bed reactor is arranged in the low pressure hydrogenation reaction zone, and the fixed bed reactor is sequentially filled with a hydrogenation protecting adsorbent and a hydrodemetallization adsorbent from top to bottom.

Table 1: properties of raw oil

Table 2: properties of the blending Components

Example 1

Mixing raw oil and hydrogen-containing gas, then entering a fixed bed reactor from the top of a low-pressure hydrogenation reaction zone, sequentially carrying out contact reaction with a hydrogenation protecting adsorbent and a hydrodemetallization adsorbent to obtain a reaction product I, extracting the reaction product I from the bottom of the fixed bed reactor, introducing the reaction product I into a gas-liquid separation zone for separation to obtain a gas-phase material flow and a liquid-phase material flow, and designating the liquid-phase material flow as S1;

wherein the raw oil composition, catalyst gradation, reaction conditions and product properties are shown in Table 3.

Blending the liquid phase material flow with low-sulfur residual oil 1 according to a mass ratio of 35:65 to obtain low-sulfur marine fuel oil which is named L1, wherein the specific parameters of the low-sulfur marine fuel oil are shown in Table 4.

Unless otherwise specified, the process flows of the remaining examples and comparative examples are the same as those of example 1, and the description thereof will not be repeated, except that the parameter information is shown in Table 3.

The procedure for producing low sulfur marine fuel oil in the remaining examples was the same as in example 1, except for the blending scheme and the major properties of the blended product, with specific parameters as shown in Table 4, unless otherwise specified.

Table 3: raw material composition, catalyst grading, reaction conditions and product properties

Table 4: blending scheme and main properties of blended product

Test case

Stability test: stability tests were performed for 6000 hours in examples 2 and 4, respectively. When the device starts to operate, the pressure drop of the reactor in the embodiment 2 is increased to 0.68MPa after the device with the pressure drop of 0.12MPa operates for 6000 hours; when the apparatus was started to operate, the reactor pressure drop of example 4 was 0.09MPa, and after 6000 hours of operation of the apparatus, the reactor pressure drop was increased to 0.65MPa. Intermittent sampling analysis was performed on the reactor outlet materials during the stability test, and the results are shown in table 5.

The solid particulates on the hydrogenation adsorbent were subjected to stability testing and the results are shown in table 6.

Table 5: product asphaltene and solid particulate content

Table 6: average content of deposited metallic element on hydrogenation adsorbent

As can be seen from the results in Table 3, the invention removes most of asphaltenes in the catalytic cracking tower bottom oil raw material, removes solid particles, can effectively protect subsequent processing devices, reduces sulfur content, and can be used as a blending component of low-sulfur marine fuel oil.

From the results of tables 5 and 6, it can be seen that the quality of the product obtained by the present invention is stable and continuous operation of the subsequent treatment apparatus can be ensured.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, a number of simple variants of the technical solution of the invention are possible, including combinations of the individual technical features in any other suitable way, which simple variants and combinations should likewise be regarded as being disclosed by the invention, all falling within the scope of protection of the invention.

Claims

1. A process for hydrogenating a catalytic cracking bottoms oil, the process comprising:

(1) Introducing raw oil containing catalytic cracking tower bottom oil and hydrogen-containing gas into a low-pressure hydrogenation reaction zone with the operating pressure not higher than 10MPa for contact reaction to obtain a reaction product I, wherein the kinematic viscosity of the catalytic cracking tower bottom oil at 100 ℃ is less than or equal to 32mm ² At least one fixed bed reactor filled with adsorbent is arranged in the low-pressure hydrogenation reaction zone, at least one hydrogenation protecting adsorbent and at least one hydrogenation function adsorbent are graded in the fixed bed reactor in sequence according to the flow direction of materials in the fixed bed reactor, and the hydrogenation function adsorbent is hydrodemetallization adsorbent and/or hydrodesulphurization adsorbent;

(2) Introducing the reaction product I into a gas-liquid separation zone for separation to obtain a gas-phase material flow and a liquid-phase material flow;

the total height-diameter ratio of each fixed bed reactor arranged in the low-pressure hydrogenation reaction zone is 5-10 independently, and is the ratio of the tangential height of the fixed bed reactor to the inner diameter of the fixed bed reactor, wherein the tangential height and the inner diameter are the same in unit;

the conditions of the low-pressure hydrogenation reaction zone at least meet the following conditions: the hydrogen partial pressure is 0.1-5.0 MPa, the reaction temperature is 100-400 ℃, and the liquid hourly space velocity is 0.10-1.0 h ^-1 The volume ratio of hydrogen to oil is 10-500;

in each of the fixed bed reactors of the low pressure hydrogenation reaction zone, each of the adsorbents independently contains a carrier and an active component supported on the carrier, the carriers are each independently selected from at least one of alumina, silica and titania, and the active components are each independently selected from at least one of a group VIB metal element and/or a group VIII metal element.

2. The hydrogenation method of a catalytic cracking bottom oil according to claim 1, wherein in the step (1), the raw oil further contains a diluent oil, and the mass ratio of the diluent oil to the catalytic cracking bottom oil is 0.05-4:1.

3. the method for hydrogenating the catalytic cracking bottom oil according to claim 2, wherein the diluent oil is at least one selected from the group consisting of catalytic diesel oil, catalytic cracking cycle oil, coal tar, and ethylene tar.

4. The hydrogenation method of a catalytic cracking bottom oil according to any one of claims 1 to 3, wherein the loading of the hydrogenation protecting adsorbent is 1 to 95% by volume and the loading of the hydrogenation functional adsorbent is 5 to 99% by volume based on the total volume of the loaded adsorbents in each of the fixed bed reactors of the low pressure hydrogenation reaction zone.

5. The hydrogenation method of a catalytic cracking bottom oil according to any one of claims 1 to 3, wherein the content of the active component in terms of oxide in the hydrogenation-protected adsorbent is 0 to 15% by weight and the content of the carrier is 85 to 100% by weight based on the mass of the hydrogenation-protected adsorbent.

6. The hydrogenation method of a catalytic cracking bottom oil according to any one of claims 1 to 3, wherein the content of the active component in terms of oxide in the hydrodemetallization adsorbent is 1 to 25% by weight and the content of the carrier is 75 to 99% by weight based on the mass of the hydrodemetallization adsorbent.

7. The hydrogenation method of a catalytic cracking bottom oil according to any one of claims 1 to 3, wherein the content of the active component in terms of oxide in the hydrodesulfurization adsorbent is 1 to 25% by weight and the content of the carrier is 75 to 99% by weight based on the mass of the hydrodesulfurization adsorbent.

8. The hydrogenation method of a catalytic cracking bottom oil according to any one of claims 1 to 3, wherein the average particle diameter of the hydrogenation-protecting adsorbent is 0.5 to 50.0mm and the bulk density is 0.3 to 1.2g/cm ³ Specific surface area of 50-300 m ² /g。

9. The hydrogenation method of a catalytic cracking bottom oil according to claim 8, wherein the average particle diameter of the hydrogenation function adsorbent is 0.2-3.0 mm and the bulk density is 0.3-0.8 g/cm ³ Specific surface area of 100-250 m ² /g。

10. The hydrogenation method of a catalytic cracking bottom oil according to any one of claims 1 to 3, wherein the initial boiling point of the catalytic cracking bottom oil is 180 ℃ to 530 ℃.

11. The hydrogenation method of a catalytic cracking bottom oil according to any one of claims 1 to 3, wherein the initial boiling point of the catalytic cracking bottom oil is 280 ℃ to 430 ℃.

12. A process for the hydrogenation of a catalytic cracking bottoms oil according to any one of claims 1-3, wherein the process further comprises obtaining said catalytic cracking bottoms oil by a process comprising the steps of:

13. The method for hydrogenating the catalytic cracking bottoms of claim 12, wherein the catalytic cracking reaction product is selected from the group consisting of products obtained from at least one of a conventional catalytic cracking process, DCC process, MIP process, HSCC process, MIP-CGP process.

14. The method for hydrogenating a catalytic cracking bottom oil according to any one of claims 1 to 3, wherein the hydrogen content in the hydrogen-containing gas in the step (1) is 20 to 100% by volume.

15. A method of producing a low sulfur marine fuel oil, the method comprising:

(i) Hydrotreating of a catalytic cracking bottoms oil by the process of any one of claims 1-14 to obtain a liquid stream as described in step (2) therein;

16. The method for producing a low sulfur marine fuel oil of claim 15 wherein the blending component is selected from at least one of atmospheric residuum, vacuum residuum, catalytic diesel, straight run wax oil, hydrogenated residuum, low sulfur diesel.

17. The method for producing a low sulfur marine fuel oil of claim 15 or 16 wherein the weight ratio of the liquid phase stream to the total weight of each of the blending components is 5:95 to 40:60.

18. the method for producing a low sulfur marine fuel oil of claim 17 wherein the weight ratio of the liquid phase stream to the total weight of each of the blending components is 10:90 to 35:65.

19. a catalytic cracking bottoms hydrogenation purification system for carrying out the hydrogenation process of any one of claims 1-14, comprising a low pressure hydrogenation reaction unit having an operating pressure of no more than 10.0MPa and a gas-liquid separation unit having a gas phase stream outlet and a liquid phase stream outlet, a feedstock feed line of the hydrogenation purification system being in communication with an inlet of the low pressure hydrogenation reaction unit, an outlet of the hydrogenation purification system being in communication with an outlet of the gas-liquid separation unit;