A method and system for residue oil hydrogenation

Abstract

The present invention relates to the field of residue oil processing, and particularly relates to a method and a system for residue oil hydrogenation. The method includes: (1) introducing inferior residue oil into a fixed-bed hydrovisbreaking reaction zone in the presence of hydrogen for hydrovisbreaking reaction to obtain a first stream; (2) introducing the first stream into a separation unit for gas-liquid separation to obtain a gas-phase stream and a liquid-phase stream; (3) introducing the liquid-phase stream into a fixed-bed hydrotreating reaction zone in the presence of hydrogen for hydrogenation reaction; controlling the operating conditions in the fixed-bed hydrovisbreaking reaction zone such that the viscosity of the liquid-phase stream at 100 °C is not more than 400 mm<supgt;2< / supgt> / s. The method provided by the present invention can enable the fixed-bed hydrotreating reaction zone to have higher reaction performance and a longer operation cycle when processing residue oil raw materials with a higher viscosity.

Description

Technical Field

[0001] The present invention relates to the field of residue oil processing, and particularly to a method and a system for residue oil hydrogenation. Background Art

[0002] The viscosity of the feedstock is one of the important factors affecting the reaction performance of the fixed-bed residue oil hydrogenation technology. This is because residue oil hydrogenation is a process controlled by internal diffusion. The higher the viscosity of the feedstock, the worse the diffusion performance of residue oil molecules. Under the same process conditions, the impurity removal rate of residue oil hydrogenation is lower.

[0003] In addition, the viscosity of the feedstock is also one of the important factors affecting the system pressure drop of the residue oil hydrogenation unit. Generally, the higher the viscosity of the feedstock, the higher the initial pressure drop of the system. High-viscosity residue oil will also cause the catalyst to coke more easily, resulting in a relatively rapid increase in the reactor pressure drop, and thus affecting the long-term operation of the unit.

[0004] Limited by the viscosity of the feedstock, conventional fixed-bed residue oil hydrogenation units usually do not only process high-viscosity vacuum residue, but introduce low-viscosity oils such as straight-run wax oil, catalytic heavy recycle oil, coker wax oil, and catalytic diesel oil into the feedstock as diluents to reduce the viscosity of the feedstock, thereby reducing the influence of the feedstock viscosity on the reaction performance and operation cycle of the fixed-bed residue oil hydrogenation unit.

[0005] According to the different feedstock properties, process conditions, and product requirements, the operation cycle of the current conventional fixed-bed residue oil hydrogenation unit can reach 1 - 2 years. At present, there are also very few fixed-bed residue units in the world that process pure vacuum residue, but their operation cycles are very short, only 3 - 6 months.

[0006] In order to solve the problem of the difficulty in processing pure vacuum residue in the existing fixed-bed residue oil hydrogenation technology, technical personnel have also proposed some new technical routes, such as residue oil visbreaking by different methods and combined processes using different reactor types, etc.

[0007] For example, CN101240187A discloses a method for visbreaking and lightening vacuum residue by ultrasonic treatment. In this method, the heavy oil is preheated and then subjected to ultrasonic radiation treatment, which can significantly reduce the viscosity of the vacuum residue, but this method faces the problems of high energy consumption and difficulty in scale-up.

[0008] CN1335371A discloses a catalytic hydroprocessing method for heavy feedstocks. In this method, the heavy hydrocarbon feedstock is first subjected to mild hydrothermal cracking in a suspension bed reactor and then fed into a fixed bed residue hydrotreating unit for hydroprocessing, so as to adapt to the heavy and inferior characteristics of the residue feedstock and extend the operating life of the fixed bed residue hydrotreating unit. However, this method faces a problem that the catalyst concentration in the suspension bed reactor is relatively low, and the reactions occurring therein are mainly thermal cracking reactions, which will to a certain extent reduce the stability of the residue colloid. In severe cases, it will lead to an increase in coke deposition on the fixed bed residue hydrotreating catalyst, thereby affecting the operating cycle of the fixed bed residue hydrotreating unit.

[0009] CN103102934A discloses a method for pretreating inferior heavy oil. In this method, the product oil from visbreaking is subjected to multi-stage centrifugal separation. Among them, each overflow component (light component) serves as the feed for the fixed bed residue hydrotreating unit, and the final underflow component (heavy component) serves as the feed for the delayed coking, solvent deasphalting or gasification unit. However, the reactions occurring during the visbreaking process are thermal cracking reactions, and the stability of the residue colloid is even worse, making it easier to cause an increase in coke deposition on the fixed bed residue hydrotreating catalyst, thereby affecting the operating cycle of the fixed bed residue hydrotreating unit. At the same time, this method also has the problem of relatively low liquid yield of high-value components. Summary of the Invention

[0010] The object of the present invention is to overcome the defects of poor reaction performance and short operating cycle when processing residue feedstocks with relatively high viscosity in existing residue hydrotreating technologies.

[0011] To achieve the above object, the first aspect of the present invention provides a method for residue hydrotreating, which includes:

[0012] (1) In the presence of hydrogen, introducing inferior residue into a fixed bed hydrovisbreaking reaction zone with a hydrogen partial pressure of 0.1 - 6.0 Mpa for hydrovisbreaking reaction to obtain a first stream;

[0013] (2) Introducing the first stream into a separation unit for gas-liquid separation to obtain a gas-phase stream and a liquid-phase stream;

[0014] (3) In the presence of hydrogen, introducing the liquid-phase stream into a fixed bed hydrotreating reaction zone for hydrotreating reaction;

[0015] The fixed bed hydrovisbreaking reaction zone contains a replaceable reactor. In the flow direction of the liquid-phase material, at least one hydrotreating protective agent and at least one hydrovisbreaking catalyst are sequentially loaded in the replaceable reactor;

[0016] Controlling the operating conditions in the fixed bed hydrovisbreaking reaction zone such that the viscosity of the liquid-phase stream obtained in step (2) at 100 °C is ≯400 mm 2 / s;

[0017] Moreover, the viscosity of the inferior residual oil at 100 °C > 500 mm 2 / s.

[0018] In a second aspect of the present invention, a residue hydrotreating system is provided, which system comprises:

[0019] A fixed-bed hydrovisbreaking reaction zone, which contains a replaceable reactor, and at least one hydrogenation protective agent and at least one hydrovisbreaking catalyst are loaded in the replaceable reactor; the fixed-bed hydrovisbreaking reaction zone is used for carrying out hydrovisbreaking reaction on inferior residual oil therein to obtain a first stream;

[0020] A separation unit, which is in fluid communication with the fixed-bed hydrovisbreaking reaction zone and is used for carrying out gas-liquid separation on the first stream therein to obtain a gas-phase stream and a liquid-phase stream;

[0021] A fixed-bed hydrotreating reaction zone, which is in fluid communication with the separation unit and is used for carrying out hydrogenation reaction on the liquid-phase stream therein. Description of the Drawings

[0022] Figure 1 It is a process flow diagram of a preferred specific embodiment of the method of the present invention.

[0023] Description of the Reference Numerals in the Drawings

[0024] 1 Inferior residual oil 2-1, 2-2 Hydrogen

[0025] 3-1, 3-2 Fixed-bed reactors 4 First stream

[0026] 5 Separation unit 6 Gas-phase stream

[0027] 7 Liquid-phase stream 8-1, 8-2 Fixed-bed reactors

[0028] 9 Reaction product Detailed Embodiments

[0029] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0030] In the present invention, unless otherwise specified, the pressures are all gauge pressures.

[0031] The inventors of the present invention have found through research that in order to enable a fixed bed to process high-viscosity inferior residue oil in a long cycle, it is necessary to adopt technical means to reduce the viscosity of the residue oil raw material. At the same time, when reducing the viscosity of the raw material, the colloidal stability of the residue oil raw material should not be significantly damaged, because the reduction of colloidal stability may lead to the precipitation of asphaltenes. In this way, even if the viscosity of the raw material is reduced, the fixed bed residue hydrotreating unit will cause catalyst coking due to the precipitation of asphaltenes, resulting in a shortened operation cycle. In order to avoid significantly damaging the colloidal stability of the residue oil raw material, a method of minimizing the proportion of thermal cracking reactions during the viscosity reduction process needs to be adopted. In view of this, the inventors have provided the solution of the present invention.

[0032] As described above, the first aspect of the present invention provides a method for residue hydrotreating, which includes:

[0033] (1) In the presence of hydrogen, introducing inferior residue oil into a fixed bed hydrovisbreaking reaction zone with a hydrogen partial pressure of 0.1 - 6.0 Mpa for hydrovisbreaking reaction to obtain a first stream;

[0034] (2) Introducing the first stream into a separation unit for gas-liquid separation to obtain a gas-phase stream and a liquid-phase stream;

[0035] (3) In the presence of hydrogen, introducing the liquid-phase stream into a fixed bed hydrotreating reaction zone for hydrogenation reaction;

[0036] The fixed bed hydrovisbreaking reaction zone contains a replaceable reactor. According to the flow direction of the liquid-phase material, at least one hydrogenation protective agent and at least one hydrovisbreaking catalyst are successively loaded in the replaceable reactor;

[0037] Controlling the operating conditions in the fixed bed hydrovisbreaking reaction zone such that the viscosity of the liquid-phase stream obtained in step (2) at 100 °C ≯ 400 mm 2 / s;

[0038] And, the viscosity of the inferior residue oil at 100 °C > 500 mm 2 / s.

[0039] Preferably, controlling the operating conditions in the fixed bed hydrovisbreaking reaction zone such that the viscosity of the liquid-phase stream obtained in step (2) at 100 °C ≯ 200 mm 2 / s. The inventors have found that by adopting the specific implementation of this preferred case, the reaction performance of the fixed bed hydrotreating reaction zone can be higher and the operation cycle can be longer.

[0040] Preferably, based on the total volume of the catalysts loaded in the fixed bed hydrovisbreaking reaction zone, the loading amount of the hydrogenation protective agent is 5 - 95% by volume, and the loading amount of the hydrovisbreaking catalyst is 5 - 95% by volume.

[0041] Preferably, the hydrogenation protecting agent contains a carrier and an active component supported on the carrier. The carrier is selected from at least one of alumina, silica, and titanium oxide. The active component contains at least one selected from Group VIB metal elements and Group VIII metal elements. Based on the total weight of the hydrogenation protecting agent, the content of the active component in terms of oxide is 0-12% by weight, and the balance is the carrier.

[0042] Preferably, the average particle size of the hydrogenation protecting agent is 3-50 mm, and the average pore diameter is 18-400 nm.

[0043] Preferably, the hydrovisbreaking catalyst contains a carrier and an active component supported on the carrier. The carrier is selected from at least one of alumina, silica, and titanium oxide. The active component contains at least one selected from Group VIB metal elements and Group VIII metal elements. Based on the total weight of the hydrovisbreaking catalyst, the content of the active component in terms of oxide is 3-30% by weight, and the balance is the carrier.

[0044] More preferably, in the hydrovisbreaking catalyst, based on the total weight of the hydrovisbreaking catalyst, the content of silica is 0.1-10% by weight. The inventors have found that by adopting the specific implementation of this preferred case, the reaction performance of the fixed-bed hydrotreating reaction zone can be higher and the operation cycle can be longer.

[0045] Preferably, the average particle size of the hydrovisbreaking catalyst is 0.8-3 mm, and the average pore diameter is 10-30 nm.

[0046] Preferably, in the fixed-bed hydrovisbreaking reaction zone, the replaceable reactor satisfies at least one of the conditions (I), (II), or (III):

[0047] (I) The hydrogenation protecting agent and the hydrovisbreaking catalyst loaded in the replaceable reactor are arranged in an online replaceable form;

[0048] (II) The replaceable reactor contains at least two fixed-bed reactors arranged in parallel, and at least one of the parallel fixed-bed reactors is online;

[0049] (III) The replaceable reactor is partially or completely cut off during operation.

[0050] In the present invention, various residue hydrotreating catalysts known in the art can be loaded in the fixed-bed hydrotreating reaction zone, including hydrotreating protective agents, hydrodemetallization agents, hydrodesulfurization agents, and hydrodearbonization catalysts. The grading ratio of various catalysts can also be carried out according to the conventional techniques in the art. The example part of the present invention exemplarily lists residue hydrotreating catalysts, and those skilled in the art should not be construed as a limitation to the present invention.

[0051] Preferably, at least one residue hydrotreating catalyst is loaded in the fixed-bed hydrotreating reaction zone. The residue hydrotreating catalyst contains a carrier and an active component supported on the carrier. The carrier is selected from at least one of alumina, silica, and titanium oxide. The active component contains at least one selected from Group VIB metal elements and Group VIII metal elements. Based on the total weight of the residue hydrotreating catalyst, the content of the active component in terms of oxide is 1-35% by weight, and the balance is the carrier.

[0052] Preferably, in the residue hydrotreating catalyst, the active component is selected from at least one of nickel element-tungsten element, nickel element-tungsten element-cobalt element, nickel element-molybdenum element, or cobalt element-molybdenum element.

[0053] Preferably, the average particle size of the residue hydrotreating catalyst is 0.8-50 mm, and the average pore diameter is 7-400 nm.

[0054] Preferably, the bulk density of the residue hydrotreating catalyst is 0.3-1.2 g / cm 3 and the specific surface area is 50-400 m 2 / g.

[0055] The residue hydrotreating catalyst and the hydrovisbreaking catalyst of the present invention may also contain additives. Exemplarily, the additive may be an oxide of phosphorus element, etc.

[0056] In the present invention, in the fixed-bed hydrotreating reaction zone, exemplarily, the order of loading the catalysts is to load the hydrotreating protective agent, the hydrodemetallization agent, and the hydrodesulfurization agent in sequence.

[0057] According to a particularly preferred specific embodiment, in the present invention, in the fixed-bed hydrotreating reaction zone, along the flow direction of the liquid-phase material, the pore diameter and particle size of the residue hydrotreating catalyst gradually decrease, and the content of the active component gradually increases.

[0058] Preferably, the fixed-bed hydrotreating reaction zone contains at least two fixed-bed reactors arranged in series.

[0059] Preferably, the reaction temperature in the fixed-bed hydrovisbreaking reaction zone is 300 - 450 °C, the liquid hourly space velocity is 0.10 - 10.0 h -1 , and the hydrogen-to-oil volume ratio is 10 - 500.

[0060] More preferably, the reaction temperature in the fixed-bed hydrovisbreaking reaction zone is 350 - 420 °C, the liquid hourly space velocity is 0.5 - 5.0 h -1 , and the hydrogen-to-oil volume ratio is 20 - 200.

[0061] Preferably, the reaction temperature in the fixed-bed hydrotreating reaction zone is 300 - 460 °C, the reaction pressure is 6 - 25 MPa, the liquid hourly space velocity is 0.1 - 1 h -1 , and the hydrogen-to-oil volume ratio is 250 - 1500.

[0062] More preferably, the reaction temperature in the fixed-bed hydrotreating reaction zone is 350 - 420 °C, the reaction pressure is 12 - 20 MPa, the liquid hourly space velocity is 0.15 - 0.4 h -1 , and the hydrogen-to-oil volume ratio is 300 - 1000.

[0063] Preferably, the viscosity of the inferior residue oil at 100 °C > 800 mm 2 / s.

[0064] Preferably, the inferior residue oil is selected from at least one of atmospheric residue, vacuum residue, and heavy oil.

[0065] The following combines Figure 1 to provide a process flow of a preferred specific implementation manner of the method for residue oil hydrogenation according to the present invention:

[0066] Mix the inferior residue oil 1 and hydrogen 2-1 and introduce them into the fixed-bed hydrovisbreaking reaction zone for hydrovisbreaking reaction. The fixed-bed hydrovisbreaking reaction zone contains two fixed-bed reactors arranged in parallel, namely fixed-bed reactor 3-1 and fixed-bed reactor 3-2. The two reactors are alternately online, and the first stream 4 is obtained by reaction;

[0067] Introduce the first stream 4 into the separation unit 5 for gas-liquid separation to obtain a gas-phase stream 6 and a liquid-phase stream 7;

[0068] Mix the liquid-phase stream 7 and hydrogen 2-2 and introduce them into the fixed-bed hydrotreating reaction zone for hydrogenation reaction. The fixed-bed hydrotreating reaction zone contains two fixed-bed reactors arranged in series, namely fixed-bed reactor 8-1 and fixed-bed reactor 8-2, and the reaction product 9 is obtained by reaction.

[0069] Under the preferred specific embodiments of the present invention, compared with the prior art, the method provided by the present invention can effectively reduce the viscosity of the liquid-phase logistics entering the fixed-bed hydrotreating reaction zone without significantly damaging the colloidal stability of the residue feedstock, thereby effectively improving the reaction performance of the fixed-bed hydrotreating reaction zone and prolonging its operation cycle.

[0070] As described above, the second aspect of the present invention provides a residue hydrotreating system, which includes:

[0071] A fixed-bed hydrovisbreaking reaction zone, which contains a replaceable reactor, and at least one hydrotreating protective agent and at least one hydrovisbreaking catalyst are loaded in the replaceable reactor; the fixed-bed hydrovisbreaking reaction zone is used for carrying out hydrovisbreaking reaction on inferior residue in it to obtain a first logistics;

[0072] A separation unit, which is in fluid communication with the fixed-bed hydrovisbreaking reaction zone and is used for carrying out gas-liquid separation on the first logistics in it to obtain a gas-phase logistics and a liquid-phase logistics;

[0073] A fixed-bed hydrotreating reaction zone, which is in fluid communication with the separation unit and is used for carrying out hydrotreating reaction on the liquid-phase logistics in it.

[0074] Preferably, in the fixed-bed hydrovisbreaking reaction zone, the replaceable reactor satisfies at least one of the conditions (I), (II), or (III):

[0075] (I) The hydrotreating protective agent and the hydrovisbreaking catalyst loaded in the replaceable reactor are set in an online replaceable form;

[0076] (II) The replaceable reactor contains at least two fixed-bed reactors arranged in parallel, and at least one of the parallel fixed-bed reactors is online;

[0077] (III) The replaceable reactor is partially or completely cut out during operation.

[0078] Preferably, the fixed-bed hydrotreating reaction zone contains at least two fixed-bed reactors arranged in series.

[0079] In the method provided by the present invention, a low-pressure hydrovisbreaking reaction zone is provided before the fixed-bed hydrotreating reaction zone. The hydrovisbreaking reaction zone uses a fixed-bed reactor, which has a high catalyst concentration. By loading a hydrovisbreaking catalyst with a certain cracking function and controlling the process conditions of the hydrovisbreaking reaction zone, the proportion of thermal cracking reaction in the hydrovisbreaking reaction is minimized as much as possible. Without significantly damaging the colloidal stability of the residue oil feedstock, the viscosity of the liquid-phase material entering the fixed-bed hydrotreating reaction zone can be effectively reduced, thereby effectively improving the reaction performance of the fixed-bed hydrotreating reaction zone and extending its operation cycle.

[0080] In the method provided by the present invention, the fixed-bed hydrovisbreaking reaction zone uses a replaceable reactor, which can avoid affecting the long-term operation of the fixed-bed hydrotreating reaction zone due to the increase in the reactor pressure drop in the hydrovisbreaking reaction zone.

[0081] The present invention will be described in detail below through examples.

[0082] In the following examples, various raw materials used without special instructions are commercially available products.

[0083] In the following examples, the composition and properties of the catalysts used are shown in Table 1. Among them, G represents a hydrogenation protective agent, V represents a hydrovisbreaking catalyst, M represents a hydrodemetallization agent, S represents a hydrodesulfurization agent, and the content therein is calculated based on the total weight of the catalyst, and the balance is the carrier.

[0084] The properties of the inferior residue oil used as the raw material in the following examples are as follows:

[0085] The density at 20 °C is 1.024 g / cm 3 , the viscosity at 100 °C is 1278 mm 2 / s, the carbon residue content is 20.1% by mass, the sulfur content is 5.44% by mass, the metal (Ni + V) content is 201 μg / g, and the asphaltene content is 9.5% by mass.

[0086] Table 1

[0087]

[0088]

[0089] Example 1

[0090] In this example, a fixed-bed hydrovisbreaking reaction zone is provided. A fixed-bed reactor is provided in the fixed-bed hydrovisbreaking reaction zone. In the flow direction of the liquid-phase material, a hydrogenation protective agent G and a hydrovisbreaking catalyst V are sequentially loaded in the fixed-bed reactor;

[0091] Mix inferior residue oil and hydrogen and introduce them into the fixed-bed hydrovisbreaking reaction zone for hydrovisbreaking reaction to obtain a first stream; introduce the first stream into a separation unit for gas-liquid separation to obtain a gas-phase stream and a liquid-phase stream.

[0092] Among them, the loading amount of the catalyst is shown in Table 2, the reaction conditions are shown in Table 3, and the properties of the inferior residue oil and the liquid-phase stream are shown in Table 4.

[0093] Example 2

[0094] This example is carried out by a method similar to that of Example 1, except that: the reaction conditions are different.

[0095] Among them, the loading amount of the catalyst is shown in Table 2, the reaction conditions are shown in Table 3, and the properties of the inferior residue oil and the liquid-phase stream are shown in Table 4.

[0096] Example 3

[0097] This example is carried out by a method similar to that of Example 1, except that: in the flow direction of the liquid-phase material, a hydrogenation protection agent G and a hydrodemetallization agent M are successively loaded in the fixed-bed reactor; and the reaction conditions are different.

[0098] Among them, the loading amount of the catalyst is shown in Table 2, the reaction conditions are shown in Table 3, and the properties of the inferior residue oil and the liquid-phase stream are shown in Table 4.

[0099] Comparative Example 1

[0100] This comparative example is carried out by a method similar to that of Example 2, except that: only ceramic balls are loaded in the fixed-bed reactor to simulate hydrovisbreaking cracking.

[0101] Among them, the loading amount is shown in Table 2, the reaction conditions are shown in Table 3, and the properties of the inferior residue oil and the liquid-phase stream are shown in Table 4.

[0102] Example 4

[0103] In this example, a fixed-bed hydrovisbreaking reaction zone and a fixed-bed hydrotreating reaction zone are provided. A fixed-bed reactor is respectively provided in the fixed-bed hydrovisbreaking reaction zone and the fixed-bed hydrotreating reaction zone. In the flow direction of the liquid-phase material, a hydrogenation protection agent G and a hydrovisbreaking catalyst V are successively loaded in the fixed-bed reactor in the fixed-bed hydrovisbreaking reaction zone, and a hydrogenation protection agent G, a hydrodemetallization agent M, and a hydrodesulfurization agent S are successively loaded in the fixed-bed reactor in the fixed-bed hydrotreating reaction zone;

[0104] Mix inferior residue oil and hydrogen and introduce them into the fixed-bed hydrovisbreaking reaction zone for hydrovisbreaking reaction to obtain a first stream; introduce the first stream into a separation unit for gas-liquid separation to obtain a gas-phase stream and a liquid-phase stream; mix the liquid-phase stream and hydrogen and introduce them into the fixed-bed hydrotreating reaction zone for hydrogenation reaction to obtain a reaction product.

[0105] In this example, a long-term stability test is carried out. Among them, the fixed-bed hydrovisbreaking reaction zone controls the viscosity of the liquid-phase stream at 100 °C ≯ 400 mm 2 / s by increasing the reaction temperature, and the fixed-bed hydrotreating reaction zone controls the sulfur content of the reaction product not to exceed 0.5 wt% by increasing the reaction temperature;

[0106] The standard for catalyst replacement in the fixed-bed hydrovisbreaking reaction zone is that the reactor pressure drop reaches 0.7 MPa or the reaction temperature reaches 410 °C, and the shutdown standard for the fixed-bed hydrotreating reaction zone is that the reactor pressure drop reaches 0.7 MPa or the reaction temperature reaches 410 °C.

[0107] Among them, the catalyst loading is shown in Table 2, the reaction conditions are shown in Table 3, and the properties of the inferior residue oil, liquid-phase stream and reaction product are shown in Table 4.

[0108] Test results: After running for 4200 h in this example, the pressure drop in the fixed-bed hydrovisbreaking reaction zone rises to 0.70 MPa. After replacing the catalyst therein and continuing to operate, after running for 8300 h, the reaction temperature in the fixed-bed hydrotreating reaction zone rises to 410 °C, and the system shuts down.

[0109] Example 5

[0110] This example is carried out by a method similar to that of Example 4. The difference is that: the fixed-bed hydrovisbreaking reaction zone controls the viscosity of the liquid-phase stream at 100 °C ≯ 200 mm 2 / s by increasing the reaction temperature.

[0111] Among them, the catalyst loading is shown in Table 2, the reaction conditions are shown in Table 3, and the properties of the inferior residue oil, liquid-phase stream and reaction product are shown in Table 4.

[0112] Test results: After running for 3500 h in this example, the pressure drop in the fixed-bed hydrovisbreaking reaction zone rises to 0.70 MPa. After replacing the catalyst therein and continuing to operate, after running for 7100 h, the pressure drop in the fixed-bed hydrovisbreaking reaction zone rises to 0.70 MPa. After replacing the catalyst therein again and continuing to operate, after running for 9800 h, the reaction temperature in the fixed-bed hydrotreating reaction zone rises to 410 °C, and the system shuts down.

[0113] Comparative Example 2

[0114] This comparative example sets up a fixed-bed hydrotreating reaction zone, in which there is a fixed-bed reactor. According to the flow direction of the liquid-phase material, a hydrogenation protective agent G, a hydrodemetallization agent M, and a hydrodesulfurization agent S are filled in the fixed-bed reactor in sequence;

[0115] The inferior residue oil and hydrogen are mixed and introduced into the fixed-bed hydrotreating reaction zone for a hydrogenation reaction to obtain a reaction product.

[0116] This comparative example conducts a long-term stability test. Among them, the sulfur content of the reaction product in the fixed-bed hydrotreating reaction zone is controlled not to exceed 0.5 wt% by increasing the reaction temperature;

[0117] The shutdown standard of the fixed-bed hydrotreating reaction zone is that the reactor pressure drop reaches 0.7 MPa or the reaction temperature reaches 410 °C.

[0118] Among them, the loading amount of the catalyst is shown in Table 2, the reaction conditions are shown in Table 3, and the properties of the inferior residue oil and the reaction product are shown in Table 4.

[0119] Test results: After this comparative example operates for 5100 h, the pressure drop in the fixed-bed hydrotreating reaction zone rises to 0.70 MPa, and the system shuts down.

[0120] Table 2

[0121]

[0122] Table 3

[0123]

[0124] Table 4

[0125]

[0126]

[0127] It can be seen from the results in Table 4 that in Examples 1-3, the fixed-bed hydrovisbreaking reaction zone effectively reduces the viscosity of the inferior residue oil. In addition, the viscosity of the liquid-phase material can be adjusted according to needs by controlling the graded catalyst and reaction conditions in the fixed-bed hydrovisbreaking zone.

[0128] Compared with Example 2, on the one hand, the visbreaking effect of hydrovisbreaking cracking is worse than that of the fixed-bed hydrovisbreaking reaction zone set in the present invention. On the other hand, hydrovisbreaking cracking will also lead to an increase in the asphaltene content of the liquid-phase material, that is, its colloidal stability becomes worse.

[0129] Example 4-5 stopped after running for 8300h and 9800h respectively, while Comparative Example 2 without a fixed-bed hydrovisbreaking reaction zone stopped after running for only 5100h, indicating that setting up a fixed-bed hydrovisbreaking reaction zone can significantly extend the operation cycle of the fixed-bed hydrotreating reaction zone.

[0130] From the above results, it can be seen that the method provided by the present invention can effectively reduce the viscosity of the liquid-phase material flow entering the fixed-bed hydrotreating reaction zone without significantly damaging the colloidal stability of the residue raw material, thereby effectively improving the reaction performance of the fixed-bed hydrotreating reaction zone when processing residue raw materials with higher viscosities and extending its operation cycle; at the same time, the fixed-bed hydrovisbreaking reaction zone adopts a replaceable reactor, which can avoid affecting the long-term operation of the fixed-bed hydrotreating reaction zone due to the increase in the reactor pressure drop in the hydrovisbreaking reaction zone.

[0131] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A method for residue hydrotreating, characterized in that, The method comprises the following steps: (1) introducing inferior residue oil into a fixed-bed hydrovisbreaking reaction zone with a hydrogen partial pressure of 0.1 - 6.0 Mpa in the presence of hydrogen to carry out hydrovisbreaking reaction, thereby obtaining a first stream; (2) introducing the first stream into a separation unit for gas-liquid separation to obtain a gas-phase stream and a liquid-phase stream; (3) introducing the liquid-phase stream into a fixed-bed hydrotreating reaction zone in the presence of hydrogen to carry out a hydrogenation reaction; The fixed-bed hydrovisbreaking reaction zone contains a replaceable reactor. Along the flow direction of the liquid-phase material, at least one hydrogenation protective agent and at least one hydrovisbreaking catalyst are successively loaded in the replaceable reactor; Control the conditions for operating in the fixed-bed hydrovisbreaking reaction zone such that the viscosity of the liquid-phase stream obtained in step (2) at 100 °C is ≯ 400 mm 2 / s; and, the viscosity of the inferior residue oil at 100 °C > 500 mm 2 / s; The hydrovisbreaking catalyst contains a carrier and an active component supported on the carrier. The carrier is a combination of silica and at least one selected from alumina and titanium oxide; the active component contains at least one selected from Group VIB metal elements and Group VIII metal elements. Based on the total weight of the hydrovisbreaking catalyst, the content of the active component in terms of oxide is 3 - 30 wt%, and based on the total weight of the hydrovisbreaking catalyst, the content of silica is 0.1 - 10 wt%; The average particle size of the hydrovisbreaking catalyst is 1.8 - 3 mm.

2. The method according to claim 1, wherein, Control the conditions for operating in the fixed-bed hydrovisbreaking reaction zone such that the viscosity of the liquid-phase stream obtained in step (2) at 100 °C is ≯ 200 mm 2 / s.

3. The method according to claim 1 or 2, wherein Based on the total volume of the catalysts loaded in the fixed-bed hydrovisbreaking reaction zone, the loading amount of the hydrogenation protective agent is 5 - 95 vol%, and the loading amount of the hydrovisbreaking catalyst is 5 - 95 vol%.

4. The method according to claim 1 or 2, wherein The hydrogenation protective agent contains a carrier and an active component supported on the carrier. The carrier is selected from at least one of alumina, silica, and titanium oxide. The active component contains at least one selected from Group VIB metal elements and Group VIII metal elements. Based on the total weight of the hydrogenation protective agent, the content of the active component in terms of oxide is 0 - 12 wt%.

5. The method according to claim 1 or 2, wherein The average particle size of the hydrogenation protective agent is 3 - 50 mm, and the average pore diameter is 18 - 400 nm.

6. The method according to claim 1 or 2, wherein The average pore diameter of the hydrovisbreaking catalyst is 10 - 30 nm.

7. The method according to claim 1 or 2, wherein In the fixed-bed hydrovisbreaking reaction zone, the replaceable reactor meets one of the conditions (I), (II), or (III): (I) The hydrogenation protective agent and the hydrovisbreaking catalyst loaded in the replaceable reactor are set in an online replaceable form; (II) The replaceable reactor contains at least two fixed-bed reactors arranged in parallel, and at least one of the parallel fixed-bed reactors is online; (III) The replaceable reactor is partially or completely cut out during operation.

8. The method according to claim 1 or 2, wherein At least one residue hydrotreating catalyst is filled in the fixed-bed hydrotreating reaction zone. The residue hydrotreating catalyst contains a carrier and an active component supported on the carrier. The carrier is selected from at least one of alumina, silica, and titanium oxide. The active component contains at least one selected from Group VIB metal elements and Group VIII metal elements. Based on the total weight of the residue hydrotreating catalyst, the content of the active component in terms of oxide is 1-35% by weight.

9. The method according to claim 8, wherein, The active component in the residue hydrotreating catalyst is selected from one of nickel-tungsten, nickel-tungsten-cobalt, nickel-molybdenum, or cobalt-molybdenum.

10. The method according to claim 9, wherein, The average particle size of the residue hydrotreating catalyst is 0.8-50 mm, and the average pore size is 7-400 nm.

11. The method according to claim 10, wherein, The bulk density of the residue hydrotreating catalyst is 0.3 - 1.2 g / cm 3 , and the specific surface area is 50 - 400 m 2 / g.

12. The method according to claim 1 or 2, wherein, The fixed-bed hydrotreating reaction zone contains at least two fixed-bed reactors arranged in series.

13. The method according to claim 1 or 2, wherein The reaction temperature in the fixed-bed hydrovisbreaking reaction zone is 300 - 450 °C, the liquid hourly space velocity is 0.10 - 10.0 h -1 , and the hydrogen-to-oil volume ratio is 10 - 500.

14. The method according to claim 13, wherein The reaction temperature in the fixed-bed hydrovisbreaking reaction zone is 350 - 420 °C, and the liquid hourly space velocity is 0.5 - 5.0 h -1 , and the hydrogen-to-oil volume ratio is 20 - 200.

15. The method according to claim 1 or 2, wherein The reaction temperature in the fixed-bed hydrotreating reaction zone is 300 - 460 °C, the reaction pressure is 6 - 25 MPa, the liquid hourly space velocity is 0.1 - 1 h -1 , and the hydrogen-to-oil volume ratio is 250 - 1500.

16. The method according to claim 15, wherein, The reaction temperature in the fixed-bed hydrotreating reaction zone is 350 - 420 °C, the reaction pressure is 12 - 20 MPa, the liquid hourly space velocity is 0.15 - 0.4 h -1 , and the hydrogen-to-oil volume ratio is 300 - 1000.

17. The method according to claim 1 or 2, wherein, The viscosity of the inferior residual oil at 100 °C > 800 mm 2 / s.

18. The method according to claim 1 or 2, wherein The inferior residue is selected from at least one of atmospheric residue and vacuum residue.

19. A residue hydrotreating system, characterized in that, This residue hydrotreating system is used to implement the residue hydrotreating method described in any one of claims 1-18. This system includes: A fixed-bed hydrovisbreaking reaction zone, which contains a replaceable reactor. At least one of the hydrogenation protecting agent and at least one of the hydrovisbreaking catalysts are filled in the replaceable reactor. The fixed-bed hydrovisbreaking reaction zone is used to carry out hydrovisbreaking reaction on the inferior residue therein to obtain a first stream. A separation unit, which is in fluid communication with the fixed-bed hydrovisbreaking reaction zone and is used to carry out gas-liquid separation on the first stream therein to obtain a gas-phase stream and a liquid-phase stream. A fixed-bed hydrotreating reaction zone, which is in fluid communication with the separation unit and is used to carry out hydrogenation reaction on the liquid-phase stream therein. The fixed-bed hydrotreating reaction zone contains at least two fixed-bed reactors arranged in series.

20. The system according to claim 19, wherein, In the fixed-bed hydrovisbreaking reaction zone, the replaceable reactor satisfies one of the conditions (I), (II), or (III): (I) The hydrogenation protecting agent and the hydrovisbreaking catalyst filled in the replaceable reactor are set in an online replaceable form. (II) The replaceable reactor contains at least two fixed-bed reactors arranged in parallel, and at least one of the parallel fixed-bed reactors is online. (III) The replaceable reactor is partially or completely cut out during operation.

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