A method and system for hydrogenating residual oil

Abstract

The present invention relates to the field of residue oil hydrogenation and discloses a method and system for residue oil hydrogenation, comprising: (1) introducing a residue oil feedstock into a downflow reactor and an upflow reactor connected in parallel in a hydrogenation pretreatment reaction zone through a total feed three-way valve for a hydrogenation pretreatment reaction, introducing the effluent of the hydrogenation pretreatment reaction into a main hydrogenation reaction zone for a hydrogenation reaction, and controlling the pressure drop of the two reactors in the hydrogenation pretreatment reaction zone to be consistent by the opening of the three-way valve; and (2) when the pressure drop of any reactor in the hydrogenation pretreatment reaction zone reaches 60% to 100% of the reactor pressure drop limit value, fixing the opening of the total feed three-way valve to remain unchanged, and dynamically introducing part of the flow entering the reactor into the first reactor downstream of the reactor in the flow direction. The present invention also avoids various problems existing in existing protective reactor technologies and has the advantages of strong raw material adaptability, high reactor utilization, simple operation, and a long operating cycle.

Description

Technical Field

[0001] The present invention relates to the field of residual oil hydrogenation, and in particular to a method and system for residual oil hydrogenation. Background Art

[0002] The combination of fixed-bed residue hydrotreating and catalytic cracking technology is one of the most mature and effective process routes for heavy oil conversion.

[0003] However, the greatest challenges of fixed-bed residue hydrotreating technology lie in improving feedstock adaptability and achieving long-term operation cycles. Currently, fixed-bed residue hydrotreating units typically operate for one to two years, which cannot match the three to four-year operating cycle of catalytic cracking units. Frequent shutdowns for maintenance severely impact refinery profitability.

[0004] The main factors affecting the operating cycle of a fixed-bed residue oil hydrotreating unit include: (1) catalyst metal (Ni+V) deposition and deactivation; (2) catalyst carbon deposition and deactivation; (3) reactor pressure difference increases beyond the limit; (4) hot spots appear in the catalyst bed, and the local temperature exceeds the limit.

[0005] To address these problems, an effective technical means to extend the operating cycle of the residue hydrotreating unit is to adopt more advanced protection reactor technology.

[0006] CN1484684A discloses a method for hydrotreating heavy hydrocarbon fractions using replaceable and short-circuitable reactors. The method involves hydrotreating heavy hydrocarbon fractions in a first hydrodemetallization section and then in a second hydrodesulfurization section, wherein the effluent from the first section passes through the second hydrodesulfurization section. The hydrodemetallization section is preceded by at least one protected zone. The hydrotreating method comprises the following steps: a) a step in which a protected zone is used; b) a step during which the protected zone is short-circuited and the catalyst contained in the section is regenerated and / or replaced; c) a step during which the protected zone, which has been regenerated and / or replaced, is reconnected; and d) a step in which at least one reactor in the hydrodemetallization section and / or hydrodesulfurization section can be short-circuited and the catalyst contained in the section can be regenerated and / or replaced. This method involves a complex switching process and significantly increases investment.

[0007] CN104119952A discloses a method for hydrotreating hydrocarbon oil, comprising: contacting a hydrocarbon oil feedstock and hydrogen with multiple hydrogenation catalyst beds in a hydrotreating unit; alternating between a primary and a backup hydrotreating reactor, wherein the primary reactor's online time is greater than the backup reactor's. This method utilizes two guard reactors, one large and one small, which improves reactor utilization efficiency, but the reactors are still not always fully utilized.

[0008] CN103059927A discloses a method for hydrotreating heavy oil products. This method removes the first hydrogenation reactor. When the pressure drop in the first hydrogenation reactor reaches an upper limit or the hotspot temperature is too high, the feedstock and hydrogen enter the second hydrogenation reactor, extending the device's operating cycle. This method can cause the guard reactor to be unusable for a long time, and during the complete removal of the guard reactor, there is a risk of overheating.

[0009] CN108018084A discloses a heavy oil hydroprocessing method for improving catalyst utilization. The method employs two parallel reactors in the hydroprocessing pretreatment reaction zone and operates at high temperature, allowing the catalyst in the main reaction zone to be regenerated and reused after one cycle. However, this method does not reduce the number of shutdowns of the residual oil hydroprocessing unit and still seriously impacts the economic benefits of the refinery.

[0010] Existing technologies have limited adaptability to raw materials. For example, when the raw material has high iron and calcium content, an upflow reactor is generally recommended as a guard reactor due to its greater capacity to accommodate these two elements. However, when the raw material has high nickel and vanadium content, a downflow reactor is generally recommended as a guard reactor due to its greater capacity to accommodate these two elements. However, existing technologies often cannot accommodate the fluctuating nature of the raw materials. For example, processing raw materials with high iron and calcium content for a period of time and high nickel and vanadium content for another period of time often results in rapid plant shutdown. Summary of the Invention

[0011] The purpose of the present invention is to overcome the shortcomings of poor raw material adaptability and short operating cycle when processing inferior residual oil raw materials in existing hydrogenation methods, and to provide a residual oil hydrogenation method and system.

[0012] In order to achieve the above object, the first aspect of the present invention provides a method for hydrogenating residual oil, which comprises:

[0013] (1) introducing a residual oil feedstock into a downflow reactor and an upflow reactor arranged in parallel in a hydrogenation pretreatment reaction zone through a total feed three-way valve to perform a hydrogenation pretreatment reaction to obtain a hydrogenation pretreatment reaction effluent; the downflow reactor and the upflow reactor are both filled with a hydrogenation pretreatment catalyst; and controlling the opening of the total feed three-way valve so that the pressure drops in the downflow reactor and the upflow reactor are the same;

[0014] (2) introducing the hydroprocessing pretreatment reaction effluent into a hydroprocessing main reaction zone to contact the hydroprocessing catalyst to perform a hydroprocessing reaction;

[0015] When the pressure drop of any reactor in the hydrogenation pretreatment reaction zone reaches 60% to 100% of the reactor pressure drop limit value, the opening of the total feed three-way valve is fixed unchanged and part of the logistics entering the reactor is dynamically introduced into the first reactor downstream of the reactor along the liquid phase logistics direction, so that the pressure drop of the reactor is controlled to be 0.1 MPa-Pmax MPa, where Pmax is the pressure drop limit value of the corresponding reactor.

[0016] A second aspect of the present invention provides a system for hydrogenating residual oil, the system comprising:

[0017] A hydropretreatment reaction zone is used to perform a hydropretreatment reaction on a residual oil feedstock. The reaction zone includes a feed main pipe, a total feed three-way valve, a downflow reactor and an upflow reactor connected in parallel, and each reactor is further equipped with a three-way valve. The first end of the total feed three-way valve is connected to the feed main pipe, and the second and third ends are connected to the feed pipelines of the downflow reactor and the upflow reactor, respectively. The first end of the three-way valve corresponding to the downflow reactor and the upflow reactor is connected to the feed pipeline of the upstream material, the second end is connected to the feed pipeline of the reactor, and the third end is connected to the feed pipeline of the first reactor downstream of the reactor in the logistics direction.

[0018] The reaction effluent from the hydropretreatment reaction zone is introduced into the hydroprocessing main reaction zone through the residue hydropretreatment product pipeline for hydroprocessing reaction. The hydroprocessing main reaction zone is provided with at least one reactor in series.

[0019] The present invention arranges a downflow reactor and an upflow reactor in parallel in a hydrogenation pretreatment reaction zone, and adjusts the ratio of the logistics entering the downflow reactor and the upflow reactor by adjusting the opening of a total feed three-way valve. This reduces the initial pressure drop of each reactor in the hydrogenation pretreatment reaction zone and improves the impurity accommodating capacity of the hydrogenation pretreatment reaction zone. At the same time, the advantages of the downflow reactor's strong capacity for accommodating metal nickel and vanadium and the upflow reactor's strong capacity for accommodating metal iron and calcium can be dynamically utilized according to the characteristics of the raw materials, thereby delaying the pressure drop increase rate of the hydrogenation pretreatment reaction zone.

[0020] Furthermore, in the middle and late stages of operation, the present invention dynamically adjusts the proportion of materials entering each reactor according to the pressure drop of each reactor in the hydrogenation pretreatment reaction zone, avoiding the risk of overheating during the complete removal of the protective reactor in the conventional removable process, while being able to fully utilize all reactors throughout the entire operation cycle.

[0021] Therefore, the present invention avoids various problems existing in the existing protection reactor technology and has the advantages of strong raw material adaptability, high reactor utilization rate, simple operation and long operation cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of a preferred embodiment of the residue oil hydrogenation method and system provided by the present invention.

[0023] Description of Reference Numerals

[0024] 1. Residue oil raw materials

[0025] 2-0, total feed three-way valve

[0026] 2-1 and 2-2 are both three-way valves

[0027] 3-1. Downflow reactor

[0028] 3-2. Upflow reactor

[0029] 4. Hydrogenation pretreatment reaction effluent mixture

[0030] 5-1, 5-2, 5-3 and 5-4 are all fixed bed reactors

[0031] 6. Hydrotreating the effluent from the main reaction zone DETAILED DESCRIPTION

[0032] The endpoints of the ranges and any values disclosed herein are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0033] As mentioned above, the first aspect of the present invention provides a method for hydrogenating residual oil, the method comprising:

[0034] (1) introducing a residual oil feedstock into a downflow reactor and an upflow reactor arranged in parallel in a hydrogenation pretreatment reaction zone through a total feed three-way valve to perform a hydrogenation pretreatment reaction to obtain a hydrogenation pretreatment reaction effluent; the downflow reactor and the upflow reactor are both filled with a hydrogenation pretreatment catalyst; and controlling the opening of the total feed three-way valve so that the pressure drops in the downflow reactor and the upflow reactor are the same;

[0035] (2) introducing the hydroprocessing pretreatment reaction effluent into a hydroprocessing main reaction zone to contact the hydroprocessing catalyst to perform a hydroprocessing reaction;

[0036] When the pressure drop of any reactor in the hydrogenation pretreatment reaction zone reaches 60% to 100% of the reactor pressure drop limit value, the opening of the total feed three-way valve is fixed unchanged and part of the logistics entering the reactor is dynamically introduced into the first reactor downstream of the reactor along the liquid phase logistics direction, so that the pressure drop of the reactor is controlled to be 0.1 MPa-Pmax MPa, where Pmax is the pressure drop limit value of the corresponding reactor.

[0037] It is well known to those skilled in the art that in both the hydropretreatment reaction step and the hydrotreatment reaction step, the reactants should include hydrogen; before the raw materials are introduced into the hydropretreatment reaction zone, they should also include steps such as heat exchange and preheating, and the hydrotreatment reaction effluent should be separated after a separation step, etc., which will not be elaborated in the present invention.

[0038] As is well known to those skilled in the art, the pressure drop limit of a fixed-bed reactor is affected by factors such as the reactor material, manufacturing process, and configuration of reactor internals. This data is typically provided by the reactor manufacturer. Currently, the pressure drop limit for most fixed-bed residue oil hydrotreating plants in my country is 0.7 MPa. However, the method of the present invention is not limited thereto.

[0039] Preferably, the pressure drop of each reactor in the hydrogenation pretreatment reaction zone is controlled to be 0.3 MPa-Pmax MPa.

[0040] According to a preferred specific embodiment, the method of the present invention further includes: when the pressure drop of the first reactor in the main hydroprocessing reaction zone reaches 60% to 100% of the reactor pressure drop limit value, dynamically introducing part of the logistics entering the reactor into the first reactor downstream of the reactor along the liquid phase logistics direction, so that the pressure drop of the reactor is controlled to 0.1 MPa-Pmax MPa, where Pmax is the corresponding reactor pressure drop limit value.

[0041] Preferably, the pressure drop of the first reactor in the main hydroprocessing reaction zone is controlled to be 0.3 MPa-Pmax MPa.

[0042] Preferably, the hydroprocessing main reaction zone contains a fixed bed reactor.

[0043] Preferably, the hydroprocessing main reaction zone contains at least one, more preferably two or more fixed bed reactors arranged in series.

[0044] Preferably, the fixed bed reactor contained in the main hydroprocessing reaction zone is at least one of a downflow reactor, an upflow reactor and a counterflow reactor.

[0045] According to a particularly preferred embodiment, the process flow of the fixed-bed residue oil hydroprocessing pretreatment reaction zone and the fixed-bed residue oil hydroprocessing main reaction zone of the present invention includes: the residue oil feedstock is introduced into the system from a feed main pipe through a total feed three-way valve, is divided into two streams, and then respectively enters a downflow reactor and an upflow reactor connected in parallel in the hydroprocessing pretreatment reaction zone; all or part of the two streams enter the reactor through the second end of the three-way valve in front of the reactor for a hydroprocessing pretreatment reaction; the reaction effluent from the hydroprocessing pretreatment reaction zone is mixed with the stream flowing through the third end of the three-way valve and then enters the hydroprocessing main reaction zone for a hydroprocessing reaction.

[0046] Preferably, the hydrogenation pretreatment catalyst comprises a hydrogenation protection catalyst and a hydrodemetallization catalyst sequentially arranged along the liquid phase flow direction.

[0047] Preferably, the hydroprocessing pretreatment 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 is a Group VIB metal and / or a Group VIII metal, and the content of the active component is 0 to 20% by weight, calculated as oxide, based on the total weight of the hydroprocessing pretreatment catalyst, with the balance being the carrier.

[0048] Preferably, the average particle size of the hydrogenation pretreatment catalyst is 1.1 to 50.0 mm, and the average pore size is 10 to 400 nm.

[0049] Preferably, the hydrogenation pretreatment catalysts loaded are one or more than two.

[0050] The hydrogenation pretreatment catalyst of the present invention may further contain an auxiliary element. For example, it may contain P element as an auxiliary element. There is no special requirement for the specific content of P element.

[0051] Preferably, the loading volume fraction of the hydroprocessing catalyst is 10% to 50% based on the total catalysts in the hydroprocessing pretreatment reaction zone and the hydroprocessing main reaction zone.

[0052] Preferably, in the main hydroprocessing reaction zone, the hydroprocessing catalyst includes at least one of a hydroprotection catalyst, a hydrodemetallization catalyst, a hydrodesulfurization catalyst and a hydroremoval of carbon residue catalyst, and the grading ratio of each catalyst can be carried out according to conventional technology.

[0053] Preferably, the hydroprocessing 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 is a Group VIB metal and / or a Group VIII metal, and the content of the active component is 0 to 35% by weight, calculated as oxide, based on the total weight of the hydroprocessing catalyst, with the balance being the carrier.

[0054] In a particularly preferred embodiment, the active metal component in the hydroprocessing catalyst is a combination of nickel-tungsten, nickel-tungsten-cobalt, nickel-molybdenum or cobalt-molybdenum.

[0055] Preferably, the average particle size of the hydroprocessing catalyst is 0.8 to 50 mm, and the average pore size is 7 to 400 nm.

[0056] Preferably, the bulk density of the hydroprocessing catalyst is 0.3 to 1.2 g / cm 3 , with a specific surface area of 50 to 400 m 2 / g.

[0057] Particularly preferably, in the present invention, in the main hydroprocessing reaction zone, along the liquid phase flow direction, the average pore size of various hydroprocessing catalysts gradually decreases, the content of active metal components gradually increases, and the average particle size gradually decreases.

[0058] According to a preferred embodiment, the reaction conditions of the hydrotreating pretreatment reaction zone and the hydrotreating main reaction zone independently meet at least the following conditions: temperature of 300-460°C, reaction pressure of 6-25 MPa, hydrogen-to-oil volume ratio of 150-1500, total liquid hourly volume space velocity of 0.1-1 h -1 More preferably, the reaction conditions of the hydrotreating pretreatment reaction zone and the hydrotreating main reaction zone independently meet at least the following requirements: temperature of 350-420°C, reaction pressure of 12-20 MPa, hydrogen-to-oil volume ratio of 200-1000, total liquid hourly volume space velocity of 0.15-0.4 h -1 .

[0059] Preferably, the residual oil feedstock is selected from at least one of deasphalted oil, coker gas oil, catalytic light cycle oil, catalytic heavy cycle oil, coker gas oil, coal liquefaction heavy oil, coal tar, atmospheric residue oil and vacuum residue oil.

[0060] As mentioned above, the second aspect of the present invention provides a system for hydrogenating residual oil, the system comprising:

[0061] A hydropretreatment reaction zone is used to perform a hydropretreatment reaction on a residual oil feedstock. The reaction zone includes a feed main pipe, a total feed three-way valve, a downflow reactor and an upflow reactor connected in parallel, and each reactor is further equipped with a three-way valve. The first end of the total feed three-way valve is connected to the feed main pipe, and the second and third ends are connected to the feed pipelines of the downflow reactor and the upflow reactor, respectively. The first end of the three-way valve corresponding to the downflow reactor and the upflow reactor is connected to the feed pipeline of the upstream material, the second end is connected to the feed pipeline of the reactor, and the third end is connected to the feed pipeline of the first reactor downstream of the reactor in the logistics direction.

[0062] The reaction effluent from the hydropretreatment reaction zone is introduced into the hydroprocessing main reaction zone through the residue hydropretreatment product pipeline for hydroprocessing reaction. The hydroprocessing main reaction zone is provided with at least one reactor in series.

[0063] Preferably, the feed pipeline of the first reactor in the main reaction zone of the hydroprocessing includes a three-way valve with adjustable opening, the first end of the three-way valve is connected to the feed pipeline of the upstream material, the second end is connected to the feed pipeline of the reactor, and the third end is connected to the feed pipeline of the first reactor downstream in the logistics direction of the reactor.

[0064] The following combination Figure 1 A preferred embodiment of the method and system of the present invention is provided.

[0065] exist Figure 1 During the operation, in the presence of hydrogen, the residual oil feedstock 1 is divided into two streams by the total feed three-way valve 2-0 and then enters the downflow reactor 3-1 and the upflow reactor 3-2 connected in parallel in the hydropretreatment reaction zone respectively through the three-way valve 2-1 and the three-way valve 2-2, and respectively contacts and reacts with the hydropretreatment catalyst in each reactor. The hydropretreatment reaction effluent mixture 4 sequentially enters the four reactors connected in series in the hydrotreatment main reaction zone, namely the fixed bed reactor 5-1, the fixed bed reactor 5-2, the fixed bed reactor 5-3 and the fixed bed reactor 5-4, and contacts and reacts with the hydrotreatment catalyst in each reactor to obtain the hydrotreatment main reaction zone effluent 6. During the operation, the residual oil feedstock 1 is divided into two streams by the total feed three-way valve 2-0 and then enters the downflow reactor 3-1 and the upflow reactor 3-2 connected in parallel in the hydropretreatment reaction zone respectively through the three-way valve 2-1 and the three-way valve 2-2, and respectively contacts and reacts with the hydropretreatment catalyst in each reactor. The hydropretreatment reaction effluent mixture 4 sequentially enters the four reactors connected in series in the hydrotreatment main reaction zone, namely the fixed bed reactor 5-1, the fixed bed reactor 5-2, the fixed bed reactor 5-3 and the fixed bed reactor 5-4, and contacts and reacts with the hydrotreatment catalyst in each reactor to obtain the hydrotreatment main reaction zone effluent 6. The opening of the total feed three-way valve 2-0 is adjusted to make the pressure drops of the downflow reactor 3-1 and the upflow reactor 3-2 consistent; after a period of operation, when the pressure drop of the downflow reactor 3-1 or the upflow reactor 3-2 of the fixed-bed hydrogenation pretreatment rises to 60% to 100% of the reactor pressure drop limit value, the opening of the fixed total feed three-way valve 2-0 is kept unchanged, and the openings of the three-way valve 2-1 and the three-way valve 2-2 are dynamically adjusted to allow part of the residual oil feedstock to enter the downflow reactor 3-1 and the upflow reactor 3-2, and part to directly enter the main reaction zone of the hydrotreatment, and the pressure drop of the downflow reactor 3-1 and the upflow reactor 3-2 is controlled between 0.1 MPa and the reactor pressure drop limit value.

[0066] Compared with the prior art, the method provided by the present invention has at least the following advantages:

[0067] (1) The present invention sets a downflow reactor and an upflow reactor in parallel in the hydrogenation pretreatment reaction zone, and adjusts the ratio of the logistics entering the downflow reactor and the upflow reactor by adjusting the opening of the total feed three-way valve. This reduces the initial pressure drop of each reactor in the hydrogenation pretreatment reaction zone and improves the capacity of the hydrogenation pretreatment reaction zone to accommodate impurities. At the same time, it can also dynamically utilize the advantages of the downflow reactor's strong capacity to accommodate metal nickel and vanadium and the upflow reactor's strong capacity to accommodate metal iron and calcium according to the characteristics of the raw materials, thereby delaying the pressure drop increase rate of the hydrogenation pretreatment reaction zone.

[0068] (2) In the middle and late stages of operation, the present invention dynamically adjusts the proportion of materials entering each reactor according to the pressure drop of each reactor in the hydrogenation pretreatment reaction zone, thereby avoiding the risk of overheating during the complete removal of the protective reactor in the conventional removable process. At the same time, all reactors have logistics passing through them during the entire operation cycle, maximizing the role of each reactor.

[0069] (3) The present invention also avoids various problems existing in the existing protection reactor technology, and has the advantages of good raw material adaptability, high reactor utilization rate, simple operation and long operation cycle.

[0070] The present invention will be described in detail below by way of examples. In the following examples, unless otherwise specified, all raw materials used can be obtained from commercial channels.

[0071] In the following examples, unless otherwise specified, the shutdown criteria for the residue oil hydrotreating system are when the pressure drop in any reactor in the reaction zone reaches 0.7 MPa or the reaction temperature reaches 410°C.

[0072] In the following examples, the reaction pressure in the reaction zone is expressed as hydrogen partial pressure.

[0073] The types and specific compositions of the catalysts used in the following examples are shown in Table 1, wherein G represents a hydrogenation protection catalyst, M1 represents a hydrodemetallization catalyst in an upflow reactor, M2 represents a hydrodemetallization catalyst in a downflow reactor, and S represents a hydrodesulfurization catalyst.

[0074] Table 1

[0075] project G M1 M2 S <![CDATA[MO3 / (wt%)]]> 5.6 8.4 8.4 15.2 NiO / (wt%) 1.1 1.5 1.5 3.5 <![CDATA[P2O5 / (wt%)]]> - 1.0 1.0 2.0 Pore volume / (mL / g) 0.85 0.68 0.68 0.60 <![CDATA[Specific surface area / (m 2 / g)]]> 110 165 165 180 Average particle size / mm 3.0 2.5 1.3 1.0 Average pore size / nm 25 14 14 11

[0076] Example 1

[0077] In this example, the hydroprocessing pretreatment reaction zone is equipped with two fixed-bed reactors R1 and R2 connected in parallel, with R1 being an upflow reactor and R2 being a downflow reactor. The main hydroprocessing reaction zone is equipped with two fixed-bed reactors R3 and R4 connected in series. The catalyst loading scheme for reactors R1-R4 is shown in Table 2, and the initial reaction conditions are shown in Table 3.

[0078] When the device starts running, the residue oil A (raw material properties are shown in Table 5) and hydrogen enter R1 and R2 through the total feed three-way valve for hydrogenation pretreatment reaction, and the pressure drop of R1 and R2 is controlled to be consistent by the opening of the total feed three-way valve. The reaction effluents of R1 and R2 are mixed and then enter R3 and R4 in turn for hydrogenation reaction. After 500 hours of operation, the properties of the effluent of the hydrotreatment main reaction zone are shown in Table 4. After that, the reaction temperature is controlled by synchronously increasing the reaction temperature of the hydrotreatment pretreatment reaction zone and the hydrotreatment main reaction zone. The sulfur content of the effluent does not exceed 0.45wt%. When the pressure drop of the reactor R1 or R2 reaches 80% of the reactor limit value (0.7MPa) for the first time, the opening of the total feed three-way valve is fixed unchanged, and the opening of the three-way valve in front of the reactor is adjusted to reduce the pressure drop of the reactor to 0.4MPa. Thereafter, whenever the pressure drop of the reactor R1 or R2 reaches 70% of the reactor limit value (0.7MPa) for the first time, the opening of the three-way valve in front of the reactor is adjusted to reduce the pressure drop of the reactor to 0.4MPa.

[0079] The shutdown criteria for the device are that the pressure drop in any reactor reaches 0.7 MPa or the reaction temperature reaches 410°C.

[0080] As a result, after running for 17,800 hours, the pressure drop of the R3 reactor in this embodiment reached 0.7 MPa, and the device was shut down.

[0081] Example 2

[0082] The reactor configuration, catalyst loading scheme, initial reaction conditions, initial operating mode, reactor temperature increase standard, and R1 and R2 feed adjustment standard of this embodiment are the same as those of Example 1. The only difference is that the raw material used in this embodiment is residual oil B (raw material properties are shown in Table 5), and the reaction temperature increase standard of the hydrotreating pretreatment reaction zone and the hydrotreating main reaction zone is to control the sulfur content of the reaction effluent to not exceed 0.20 wt%.

[0083] The shutdown criteria for the device are that the pressure drop in any reactor reaches 0.7 MPa or the reaction temperature reaches 410°C.

[0084] As a result, after running for 19600 hours, the pressure drop of the reactor of Example R3 reached 0.7 MPa, and the device was shut down.

[0085] Example 3

[0086] The residual oil feedstock, reactor settings, catalyst loading scheme, initial reaction conditions, initial operating mode, reactor temperature increase standards, and R1 and R2 feed adjustment standards of this embodiment are the same as those of Example 1, except that the following operating standard is added: whenever the R3 pressure drop reaches 60% of the reactor limit value (0.7 MPa), the opening of the three-way valve in front of the R3 reactor is adjusted to reduce the pressure drop of the R3 reactor to 0.3 MPa.

[0087] The shutdown criteria for the device are that the pressure drop of the R4 reactor reaches 0.7 MPa or the reaction temperature reaches 410°C.

[0088] As a result, after running for 20700 hours, the reaction temperature of this embodiment reached 410°C and the device was shut down.

[0089] Comparative Example 1

[0090] Comparative Example 1 adopts a conventional one-reverse removable process flow, that is, R1-R4 are set in series at the beginning, the catalyst loading scheme of R1-R4 is shown in Table 2, and the initial reaction conditions are shown in Table 3.

[0091] Residue A and hydrogen were sequentially introduced into R1-R4 for hydroprocessing. The properties of the effluent from the main hydroprocessing reaction zone after 500 hours of operation are shown in Table 4. The sulfur content of the reaction effluent was then controlled to no more than 0.45 wt% by simultaneously increasing the reaction temperatures in the pre-hydroprocessing and main hydroprocessing reaction zones. When the pressure drop in R1 reached 0.7 MPa, the three-way valve in front of R1 completely shut R1 out of the process, and the residue feedstock and hydrogen were directed entirely to R2.

[0092] The shutdown criteria for the device are that the pressure drop in any reactor among R2-R4 reaches 0.7MPa or the reaction temperature reaches 410℃.

[0093] When the operation reached 15700 hours, the reaction temperature of this comparative example reached 410°C and the device was shut down.

[0094] Comparative Example 2

[0095] Comparative Example 2 uses exactly the same process flow and operation method as Comparative Example 1, the only difference being that the raw material is residue oil B, and the reaction temperature increase standard of the hydrotreating pretreatment reaction zone and the hydrotreating main reaction zone is to control the sulfur content of the reaction effluent to not exceed 0.20wt%.

[0096] The shutdown criteria for the device are that the pressure drop in any of the reactors R2-R4 reaches 0.7 MPa or the reaction temperature reaches 410°C.

[0097] At 17,300 h of operation, the pressure drop of the R2 reactor of this comparative example reached 0.7 MPa, and the device was shut down.

[0098] Table 2

[0099] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 R1 G / ml 50 50 50 50 50 M1 / ml 50 50 50 50 50 R1 total / ml 100 100 100 100 100 R2 G / ml 50 50 50 50 50 M2 / ml 50 50 50 50 50 R2 total / ml 100 100 100 100 100 R3 G / ml 30 30 30 30 30 M2 / ml 70 70 70 70 70 R3 total / ml 100 100 100 100 100 R4 M2 / ml 100 100 100 100 100 S / ml 400 400 400 400 400 R4 total / ml 500 500 500 500 500 (R1+R2+R3+R4) total / ml 800 800 800 800 800

[0100] Table 3

[0101] Process conditions Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Reaction temperature, °C 370 370 370 370 370 Hydrogen partial pressure, MPa 15 15 15 15 15 Hydrogen to oil ratio (volume) 800 800 800 800 800 <![CDATA[Total liquid hourly space velocity, hr -1 > 0.17 0.17 0.17 0.17 0.17

[0102] Table 4

[0103] project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Hydrotreating main reaction zone effluent <![CDATA[Density (20 °C), g / cm 3 > 0.930 0.928 0.930 0.930 0.928 Carbon residue, mass% 5.1 5.9 5.1 5.1 5.9 Sulfur content, mass% 0.45 0.19 0.45 0.45 0.19 Metal (Ni+V) content, μg / g 13.5 8.1 13.5 13.5 8.1 Metal (Fe+Ca) content, μg / g 1.5 2.3 1.5 1.5 2.3

[0104] Table 5

[0105]

[0106]

[0107] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A method for hydrogenating residual oil, characterized in that: The method includes: (1) introducing a residual oil feedstock into a downflow reactor and an upflow reactor arranged in parallel in a hydrogenation pretreatment reaction zone through a total feed three-way valve to carry out a hydrogenation pretreatment reaction to obtain a hydrogenation pretreatment reaction effluent; the downflow reactor and the upflow reactor are both filled with a hydrogenation pretreatment catalyst; and controlling the opening of the total feed three-way valve so that the pressure drops in the downflow reactor and the upflow reactor are the same; (2) introducing the hydroprocessing pretreatment reaction effluent into the hydroprocessing main reaction zone to contact with the hydroprocessing catalyst to perform a hydroprocessing reaction; When the pressure drop of any reactor in the hydrogenation pretreatment reaction zone reaches 60% to 100% of the reactor pressure drop limit value, the opening of the total feed three-way valve is fixed unchanged and part of the logistics entering the reactor is dynamically introduced into the first reactor downstream of the reactor along the liquid phase logistics direction, so that the pressure drop of the reactor is controlled to be 0.1 MPa-Pmax MPa, where Pmax is the pressure drop limit value of the corresponding reactor.

2. The method according to claim 1, wherein The pressure drop of each reactor in the hydrogenation pretreatment reaction zone is controlled to be 0.3 MPa-Pmax MPa.

3. The method according to claim 1 or 2, wherein: The method also includes: at least two reactors connected in series are provided in the main hydroprocessing reaction zone; when the pressure drop of the first reactor in the main hydroprocessing reaction zone reaches 60% to 100% of the reactor pressure drop limit value, part of the logistics entering the reactor is dynamically introduced into the first reactor downstream of the reactor along the liquid phase logistics direction, so that the pressure drop of the reactor is controlled to be 0.1 MPa-Pmax MPa, where Pmax is the corresponding reactor pressure drop limit value.

4. The method according to claim 3, wherein: The pressure drop of the first reactor in the main hydroprocessing reaction zone is controlled to be 0.3 MPa-Pmax MPa.

5. The method according to claim 1 or 2, wherein: The main hydroprocessing reaction zone contains a fixed bed reactor.

6. The method according to claim 1 or 2, wherein: The fixed bed reactor contained in the main hydroprocessing reaction zone is selected from at least one of a downflow reactor, an upflow reactor and a counterflow reactor.

7. The method according to claim 1 or 2, wherein: The hydrogenation pretreatment catalyst comprises a hydrogenation protection catalyst and a hydrogenation demetallization catalyst which are sequentially arranged along the liquid phase flow direction.

8. The method according to claim 1 or 2, wherein: The hydroprocessing pretreatment 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 is a Group VIB metal and / or a Group VIII metal, and the content of the active component is greater than 0 and less than or equal to 20% by weight, calculated as oxide, based on the total weight of the hydroprocessing pretreatment catalyst, with the balance being the carrier.

9. The method according to claim 8, wherein The average particle size of the hydrogenation pretreatment catalyst is 1.1-50.0 mm, and the average pore size is 10-400 nm.

10. The method according to claim 1 or 2, wherein: Based on the total catalysts in the hydroprocessing pretreatment reaction zone and the hydroprocessing main reaction zone, the loading volume fraction of the hydroprocessing pretreatment catalyst is 10% to 50%.

11. The method according to claim 1 or 2, wherein: The hydroprocessing catalyst contains a carrier and an active component supported on the carrier, the carrier is selected from at least one of alumina, silica and titania, the active component is a Group VIB metal and / or a Group VIII metal, and the content of the active component, calculated as oxide, is greater than 0 and less than or equal to 35% by weight, based on the total weight of the hydroprocessing catalyst, with the balance being the carrier.

12. The method according to claim 11, wherein The average particle size of the hydroprocessing catalyst is 0.8-50 mm, and the average pore size is 7-400 nm.

13. The method according to claim 12, wherein: The bulk density of the hydroprocessing catalyst is 0.3-1.2 g / cm 3 , with a specific surface area of 50~400m 2 / g.

14. The method according to claim 1 or 2, wherein: The reaction conditions of the hydrotreating pretreatment reaction zone and the hydrotreating main reaction zone independently meet at least the following requirements: temperature of 300-460°C, reaction pressure of 6-25 MPa, hydrogen-to-oil volume ratio of 150-1500, total liquid hourly volume space velocity of 0.1-1 h -1 .

15. The method according to claim 1 or 2, wherein: The reaction conditions of the hydrotreating pretreatment reaction zone and the hydrotreating main reaction zone independently meet at least the following requirements: temperature of 350-420°C, reaction pressure of 12-20 MPa, hydrogen-to-oil volume ratio of 200-1000, total liquid hourly volume space velocity of 0.15-0.4 h -1 .

16. The method according to claim 1 or 2, wherein: The residual oil raw material is selected from at least one of atmospheric residual oil and vacuum residual oil.

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