Method and system for anaerobic filling of catalyst in fixed bed reactor

Abstract

The invention relates to a method and a system for anaerobic filling of a fixed bed reactor with a catalyst. The method comprises the following steps: S1, enabling a catalyst to be in contact with wax in an ex-device filling container, and carrying out wax coating treatment to obtain a wax-coated catalyst; s2, enabling the wax-coated catalyst and solid carbon dioxide to enter a fixed bed reactor for anaerobic filling of the catalyst. According to the invention, the condition that the performance of the catalyst is damaged due to contact with oxygen in the filling process can be avoided, and the problem that the active metal-containing catalyst is difficult to fill in the industry at present is solved.

Description

Technical Field

[0001] The present application relates to the field of catalyst loading, and in particular, to a method and system for anaerobic loading of catalysts in a fixed bed reactor. Background Art

[0002] Reactors in the petrochemical industry are usually fixed bed reactors, and the catalyst is loaded into the reactor in a certain order through a certain loading method. At present, the industrial catalyst loading methods are usually ordinary loading (bag loading, sparse phase loading) and dense phase loading. Ordinary loading is a loading method in which the catalyst flows from the hopper located at the top of the reactor through a canvas bag connected to the discharge port at the bottom of the hopper into the catalyst material layer inside the reactor, and is manually sprinkled on the material surface by personnel standing on the material layer. Dense phase loading is a loading method in which a dense phase loader is used to sprinkle the catalyst so that it is relatively uniformly distributed in the radial and longitudinal directions. However, in both ordinary loading and dense phase loading methods, the catalyst is in an air atmosphere during the loading process, and is not suitable for loading active metals, catalysts that will burn or explode when in contact with air, and catalysts that must avoid contact with air during the loading process. In the face of loading catalysts that cannot contact air, the existing loading methods cannot meet the requirements.

[0003] The catalyst loading technology directly affects the catalyst loading quality, and the catalyst loading quality directly affects the progress of the chemical reaction, thereby affecting the technical and economic indicators of the device and even safe production.

[0004] CN207478537U discloses a catalyst loading device and a fixed bed reactor containing the catalyst loading device, the device comprising a barrel support, an outer surface and a connecting member. Although the device of this scheme can effectively improve the flatness during the catalyst loading process and improve the loading efficiency, it cannot achieve air-isolated loading. CN102862833A is a dense phase loading device, with a conical distributor at the bottom, and strip holes are opened on the conical surface of the distributor. The catalyst directly enters the rotating distributor from the barrel and is evenly thrown out from the strip holes, thereby achieving dense phase loading.

[0005] Although the above disclosed loading methods can complete the catalyst loading of the fixed bed reactor, they cannot solve the problem of anaerobic loading in which the catalyst does not come into contact with oxygen. When the catalyst required for the reaction contains active metals that cannot come into contact with oxygen, the existing disclosed loading methods cannot meet the requirements. Summary of the invention

[0006] The purpose of the present disclosure is to provide a method and system for oxygen-free loading of catalysts in a fixed bed reactor, which can avoid the performance of the catalyst being destroyed due to contact with oxygen during the loading process, and solve the current problem of difficulty in loading catalysts containing active metals in the industry.

[0007] In order to achieve the above object, the present disclosure provides, in a first aspect, a method for loading a catalyst in a fixed bed reactor without oxygen, comprising the following steps:

[0008] S1, contacting the catalyst with wax in an external filling container to perform wax coating treatment to obtain a wax-coated catalyst;

[0009] S2, allowing the wax-coated catalyst and solid carbon dioxide to enter a fixed bed reactor for oxygen-free loading of the catalyst.

[0010] Optionally, the weight ratio of the catalyst to the wax added to the external filling container is 1:(0.001-10), preferably 1:(0.01-1);

[0011] Preferably, the wax is selected from paraffin wax and / or microcrystalline wax, the bromine index of the wax is less than 100 mgBr / 100 g, and the melting point of the wax is greater than 45°C.

[0012] Optionally, in step S1, the external filling container is a container with a stirring function; the conditions for the wax coating treatment include: a temperature of 60 to 350°C, preferably 80 to 150°C; a stirring speed of 10 to 200 rpm, preferably 30 to 100 rpm; a mixing time of 1 to 200 minutes, preferably 5 to 60 minutes; an operating pressure of 0.1 to 5 MPa, preferably 0.1 to 0.5 MPa; and an inert atmosphere in the external filling container.

[0013] Optionally, step S2 includes:

[0014] introducing the wax-coated catalyst into a fixed bed reactor, and simultaneously introducing solid carbon dioxide into the fixed bed reactor, so that the wax-coated catalyst is in contact with the solid carbon dioxide;

[0015] Optionally, step S2 further comprises: during the anaerobic loading of the catalyst, introducing one or more of an inert gas or a carbon dioxide gas into the fixed bed reactor.

[0016] Optionally, the conditions for loading the catalyst in step S2 include: a weight ratio of solid carbon dioxide to catalyst of (0.01 to 100):1, preferably (0.05 to 1):1; an operating temperature of -30 to 100°C, preferably 0 to 40°C, a temperature rise in the fixed bed reactor during loading of less than 5°C, preferably less than 1°C; a pressure of 0.1 to 5MPa, preferably 0.1 to 0.5MPa; an introduction rate of the wax-coated catalyst of 1 to 1000Kg / min, preferably 5 to 200Kg / min; and an introduction rate of solid carbon dioxide of 0.01 to 10000Kg / min, preferably 2.5 to 500Kg / min.

[0017] Optionally, the amount of inert gas supplemented per hour is 0.1 to 10 times the total volume of the fixed bed reactor; preferably, the amount of inert gas supplemented per hour is 1 to 5 times the total volume of the fixed bed reactor;

[0018] Optionally, the inert gas is selected from one or more of nitrogen, argon and helium; the oxygen content of the inert gas is less than 10 ppm, preferably less than 3 ppm; the water content is less than 10 ppm, preferably less than 3 ppm.

[0019] Optionally, the method comprises:

[0020] Loading the catalyst layer by layer from bottom to top in the fixed bed reactor;

[0021] Preferably, the steps include:

[0022] During the loading process of each layer of catalyst, a grid support plate is first set in the fixed bed reactor and large and small ceramic balls are loaded; then the wax-coated catalyst is introduced into the fixed bed reactor through a loading tube, solid carbon dioxide is introduced through a solid carbon dioxide supplementary inlet at the top of the fixed bed reactor, and inert gas is introduced through an inert gas inlet at the bottom of the fixed bed reactor.

[0023] Optionally, the catalyst contains an active metal component; preferably, the active metal is selected from one or more of sodium, potassium, lithium, magnesium, aluminum and iron;

[0024] Optionally, the catalyst includes a catalyst for preparing 4-methyl-1-pentene by propylene dimerization.

[0025] A second aspect of the present disclosure provides a system for oxygen-free loading of catalyst in a fixed bed reactor, the system comprising an external loading container and a fixed bed reactor; the external loading container comprises a catalyst inlet, a wax inlet and a wax-coated catalyst outlet;

[0026] The fixed bed reactor comprises a wax-coated catalyst inlet and a solid carbon dioxide inlet; the wax-coated catalyst outlet of the external filling container is connected to the wax-coated catalyst inlet of the fixed bed reactor through a filling pipe;

[0027] The external filling container is configured such that the catalyst and the wax are contacted in the external filling container to be wax-coated to obtain a wax-coated catalyst;

[0028] The fixed bed reactor is configured to allow the wax-coated catalyst and solid carbon dioxide to enter the fixed bed reactor for oxygen-free loading of the catalyst.

[0029] Optionally, the external filling container includes one of a catalyst kettle, a circular hopper and a square hopper; preferably, the external filling container is a catalyst kettle with a stirrer installed therein; the wax-coated catalyst outlet is provided at the lower part of the external filling container;

[0030] Optionally, the diameter of the filling tube is 50 to 300 mm; Optionally, the filling tube is selected from a cloth bag or a metal hose;

[0031] Preferably, the fixed bed reactor further comprises an inert gas inlet for replenishing inert gas during the catalyst loading process.

[0032] Through the above technical scheme, the present disclosure provides a method and system for anaerobic loading of catalysts in a fixed bed reactor. With the help of an external loading container, the fixed bed reactor is loaded with catalysts in a wax-coated manner and in combination with solid carbon dioxide (dry ice). The present disclosure can achieve the completion of the catalyst loading work in the fixed bed reactor in an air-isolated state through a simple method, thereby ensuring that the catalyst does not contact oxygen and its performance is not damaged, ensuring the safety of the loading process and thus not affecting the normal progress of the reaction and the service life of the catalyst. The method is suitable for fixed bed reactors that require sealed loading of catalysts, and can solve the problem of difficulty in loading catalysts containing active metals.

[0033] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0035] Figure 1 This is a schematic structural diagram of a system for oxygen-free loading of catalyst in a fixed bed reactor provided by the present disclosure;

[0036] Figure 2 It is a structural schematic diagram of the filling system adopted in comparative example 4 of the present disclosure.

[0037] Description of Reference Numerals

[0038] 1-cylinder; 2-upper head; 3-lower head; 4-catalyst kettle; 5-catalyst kettle catalyst interface; 6-catalyst filling tube; 7-reactor solid carbon dioxide interface; 8-inert gas interface; 9-catalyst bed; 10-small ceramic ball; 11-large ceramic ball; 12-grid support plate; 13-catalyst kettle wax interface. DETAILED DESCRIPTION

[0039] The specific embodiments of the present disclosure are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure, and are not used to limit the present disclosure.

[0040] A first aspect of the present disclosure provides a method for anaerobic loading of a catalyst in a fixed bed reactor, comprising the following steps:

[0041] S1, contacting the catalyst with wax in an external filling container to perform wax coating treatment to obtain a wax-coated catalyst;

[0042] S2, allowing the wax-coated catalyst and solid carbon dioxide to enter a fixed bed reactor for oxygen-free loading of the catalyst.

[0043] The present disclosure provides a method and system for anaerobic loading of catalysts in a fixed bed reactor. The fixed bed reactor is loaded with catalysts by using an external loading container, wax coating and solid carbon dioxide (dry ice). The present disclosure can complete the catalyst loading work in the fixed bed reactor in an air-tight state by a simple method, thereby ensuring that the catalyst does not contact oxygen and its performance is not damaged, ensuring the safety of the loading process and thus not affecting the normal progress of the reaction and the service life of the catalyst. The present disclosure is suitable for fixed bed reactors that require sealed loading of catalysts, and can solve the problem of difficulty in loading catalysts containing active metals.

[0044] In the present disclosure, the catalyst is first mixed with wax in an external filling container to achieve wax coating on the catalyst surface to form a wax protective layer; then the wax-coated catalyst is introduced into the reactor, and solid carbon dioxide (i.e., dry ice) is introduced to contact and mix with the wax-coated catalyst in the reactor, the solid carbon dioxide is distributed around the wax-coated catalyst, and after the solid carbon dioxide is converted into gaseous CO2, carbon dioxide protection is further formed around the wax-coated catalyst to achieve the effect of blocking air; and the gaseous CO2 can further push the air in the reactor to rise during the rising process until it is discharged from the reactor.

[0045] In one embodiment, the catalyst contains an active metal component; preferably, the active metal is selected from one or more of sodium, potassium, lithium, magnesium, aluminum and iron.

[0046] In a specific embodiment, the catalyst includes a catalyst for preparing 4-methyl-1-pentene by propylene dimerization reaction, and the catalyst may include one or both of sodium and potassium.

[0047] In a specific embodiment, the wax is selected from paraffin wax and / or microcrystalline wax, the bromine index of the wax is less than 100 mgBr / 100 g, and the melting point of the wax is greater than 45°C.

[0048] The catalyst and wax in the present disclosure can be purchased from commercial channels or prepared by known methods.

[0049] In one embodiment, the weight ratio of the catalyst to the wax added to the external loading container is 1:(0.001-10), preferably 1:(0.01-1). Mixing the catalyst and the wax according to the weight ratio in this embodiment can achieve an excellent catalyst wax coating effect, which is conducive to the realization of anaerobic loading of the catalyst.

[0050] In one embodiment, in step S1, the external filling container is a container with a stirring function; the conditions for the wax coating treatment include: a temperature of 60 to 350°C; a stirring speed of 10 to 200 rpm; a mixing time of 1 to 200 minutes; an operating pressure of 0.1 to 5 MPa; and an inert atmosphere in the external filling container.

[0051] In a preferred embodiment, in step S1, the wax coating treatment conditions include: temperature of 80-150°C; stirring speed of 30-100 rpm; mixing time of 5-60 minutes; operating pressure of 0.1-0.5 MPa; inert atmosphere in the external filling container. The preferred mixing conditions in this embodiment can achieve a more uniform mixing effect of the catalyst and the wax in the external filling container, so that the wax coating on the catalyst surface is more uniform.

[0052] In a specific implementation, step S2 includes:

[0053] The wax-coated catalyst is introduced into a fixed bed reactor, and solid carbon dioxide is simultaneously introduced into the fixed bed reactor, so that the wax-coated catalyst is in contact with the solid carbon dioxide.

[0054] In a specific embodiment, the conditions for loading the catalyst in step S2 include: a weight ratio of solid carbon dioxide to catalyst of (0.01 to 100): 1; an operating temperature of -30 to 100°C, a temperature rise in the fixed bed reactor of less than 5°C during loading; a pressure of 0.1 to 5MPa; an introduction rate of the wax-coated catalyst of 1 to 1000Kg / min; and an introduction rate of solid carbon dioxide of 0.01 to 10000Kg / min.

[0055] In a preferred embodiment, the catalyst loading conditions in step S2 include: the weight ratio of solid carbon dioxide to catalyst is (0.05-1):1; the operating temperature is 0-40°C, and the temperature rise in the fixed bed reactor during the loading process is less than 1°C; the pressure is 0.1-0.5MPa; the introduction rate of the wax-coated catalyst is 5-200Kg / min; the introduction rate of solid carbon dioxide is 2.5-500Kg / min. According to the conditions of this embodiment, a better catalyst oxygen-free loading effect can be ensured.

[0056] In a preferred embodiment, step S2 further comprises: during the anaerobic loading of the catalyst, introducing one or more of an inert gas or carbon dioxide gas into the fixed bed reactor. The present disclosure further introduces an inert gas into the reactor during the catalyst loading process, which can better facilitate the anaerobic loading of the catalyst.

[0057] In the present disclosure, when the temperature rise during the filling process exceeds the above range, it can be controlled by adjusting (or increasing) the amount of solid carbon dioxide added (or the ratio to the amount of catalyst filled) and increasing the inert gas flow rate so that the temperature rise is within the above temperature rise range of the present disclosure.

[0058] In a specific embodiment, the amount of inert gas supplemented per hour is 0.1 to 10 times the total volume of the fixed bed reactor; preferably, the amount of inert gas supplemented per hour is 1 to 5 times the total volume of the fixed bed reactor.

[0059] In the present disclosure, the inert gas is selected from one or more of nitrogen, argon and helium; the oxygen content of the inert gas is less than 10 ppm, preferably less than 3 ppm; the water content is less than 10 ppm, preferably less than 3 ppm.

[0060] In the present disclosure, the bed layer in the fixed bed reactor may be one layer or multiple layers.

[0061] In a specific embodiment, when the reactor is provided with a multi-layer bed, the method comprises:

[0062] Loading the catalyst layer by layer from bottom to top in the fixed bed reactor;

[0063] Preferably, the steps include:

[0064] During the loading process of each layer of catalyst, a grid support plate is first set in the fixed bed reactor, and large and small ceramic balls are loaded; then the wax-coated catalyst is introduced into the fixed bed reactor through the loading tube, solid carbon dioxide is introduced through the solid carbon dioxide supplementary inlet at the top of the fixed bed reactor, and inert gas is introduced through the inert gas inlet at the bottom of the fixed bed reactor. After completing the loading of the catalyst in the current bed, the grid support plate, large and small ceramic balls are repeatedly installed, and the catalyst loading of the next bed is carried out until the closed reactor is completed. During the repeated installation process, inert gas is continuously introduced into the reactor to ensure that the loaded catalyst does not come into contact with air.

[0065] In the present disclosure, the grid support plate, the large ceramic balls and the small ceramic balls are all conventional choices in the art, and the arrangement method is also conventional operation in the art.

[0066] A second aspect of the present disclosure provides a system for oxygen-free loading of catalyst in a fixed bed reactor, the system comprising an external loading container and a fixed bed reactor; the external loading container comprises a catalyst inlet, a wax inlet and a wax-coated catalyst outlet;

[0067] The fixed bed reactor comprises a wax-coated catalyst inlet and a solid carbon dioxide inlet; the wax-coated catalyst outlet of the external filling container is connected to the wax-coated catalyst inlet of the fixed bed reactor through a filling pipe;

[0068] The external filling container is configured such that the catalyst and the wax are contacted in the external filling container to be wax-coated to obtain a wax-coated catalyst;

[0069] The fixed bed reactor is configured to allow the wax-coated catalyst and solid carbon dioxide to enter the fixed bed reactor for oxygen-free loading of the catalyst.

[0070] The fixed bed reactor disclosed in the present invention is a conventional device structure in the art.

[0071] In one embodiment, the external filling container includes one of a catalyst kettle, a circular hopper and a square hopper; preferably, the external filling container is a catalyst kettle with a built-in agitator; and the wax-coated catalyst outlet is provided at the lower part of the external filling container.

[0072] In a specific implementation manner, the diameter of the filling tube is 50 to 300 mm; the filling tube is selected from a cloth bag or a metal hose.

[0073] In a preferred embodiment, the fixed bed reactor further comprises an inert gas inlet for replenishing inert gas during the catalyst loading process.

[0074] In the present disclosure, the solid carbon dioxide inlet is arranged at the top of the fixed bed reactor (such as the upper end cap), and the inert gas supplementary inlet is arranged at the bottom of the fixed bed reactor (such as the lower end cap).

[0075] In a specific implementation manner, the present disclosure is used Figure 1 The specific process of the system shown for oxygen-free loading of catalyst in a fixed bed reactor includes:

[0076] The prepared catalyst is added to the catalyst kettle 4 through the catalyst kettle catalyst interface 5, and wax is added to the kettle through the catalyst kettle wax interface 13 at this time, the operating temperature and pressure in the kettle are adjusted to a suitable value, and the stirred kettle is started to stir and coat the wax so that the catalyst surface is evenly loaded with wax. The fixed bed reactor bed layer is first installed with a grid support plate 12, and then large porcelain balls 11 and small porcelain balls 10 are loaded, and then the catalyst loaded with wax is loaded into the fixed bed reactor through a catalyst loading tube 6. At the same time, the reactor is supplemented with dry ice and inert gas through a solid carbon dioxide (dry ice) interface 7 and an inert gas interface 8, and the inert gas is continuously introduced, and the loading of dry ice with the catalyst is continuously supplemented. After completing the catalyst loading of the current bed layer, the grid support plate 12, large porcelain balls 11 and small porcelain balls 10 are repeatedly installed, and the catalyst loading of the next bed layer is carried out until all the closed reactors are completed.

[0077] The present disclosure is further described in detail by way of examples. The raw materials used in the examples can all be obtained through commercial sources.

[0078] The catalyst is a propylene catalyst prepared by referring to the method disclosed in CN115193462A (specifically Example 4): comprising a carrier and Na and K loaded thereon, the carrier is mixed with a modifier solution through an alkali metal salt, the alkali metal salt is potassium carbonate and sodium carbonate, and the modifier solution is mainly crown ether.

[0079] Dry ice was purchased from commercial sources. Nitrogen was used as the inert gas. Wax was No. 56 fully refined paraffin wax, purchased from commercial sources; the bromine index of the wax was 50 mgBr / 100 g, and the melting point of the wax was 56°C.

[0080] Example 1

[0081] The specifications of the external filling container are catalyst kettle with an inner diameter of 2000mm and a height of 3000mm;

[0082] Specifications of the fixed bed reactor: The inner diameter of the reactor is 3000mm, the height is 6500mm, there are two catalyst beds, and the catalyst filling height of a single bed is 2000mm.

[0083] use Figure 1 The loading system shown in the figure performs oxygen-free loading of catalyst in a fixed bed reactor, specifically comprising the following steps:

[0084] (1) A catalyst and wax are brought into contact in an off-site filling container for wax coating treatment to obtain a wax-coated catalyst; wherein the weight ratio of the catalyst to the wax is 1:0.5; the off-site filling container is a container with a stirring function; the mixing conditions include: a temperature of 90° C., a stirring speed of 50 rpm, and a mixing time of 40 minutes; an operating pressure of 0.2 MPa; and an inert atmosphere in the off-site filling container.

[0085] (2) After the wax coating is completed, the wax-coated catalyst is loaded into the reactor through a metal hose. At the same time, the reactor is supplemented with 1 times the amount of catalyst in dry ice (the weight ratio of catalyst to dry ice is 1:1) and 3 times / hour of nitrogen in the total volume of the reactor through the dry ice interface. The filling temperature in the reactor is 30°C. During the filling process, the temperature rise in the fixed bed reactor is controlled to be below 1°C. The pressure in the reactor is 0.2MPa. The introduction rate of the wax-coated catalyst is 100Kg / min, and the introduction rate of solid carbon dioxide is 100Kg / min.

[0086] The above process is followed to complete the loading of one layer of catalyst; the reactor of this embodiment is loaded with 2 layers in total.

[0087] After the filling is completed, the reactor is closed until the reaction material is fed to conduct a reaction performance test, which specifically includes the following steps;

[0088] Propylene was used as raw material, and the propylene catalyst prepared above was used to carry out propylene dimerization reaction. The reaction conditions were temperature 155°C, pressure 7Mpa, space velocity 0.6h -1 After the propylene dimerization reaction was stable for 2 hours, the reactor outlet material 4-methyl-1-pentene entered the online chromatographic analyzer for composition analysis to obtain propylene conversion rate data. The propylene conversion rate calculation formula is shown in the following formula (1).

[0089]

[0090] Example 2

[0091] use Figure 1 The loading system shown in the figure performs oxygen-free loading of catalyst in a fixed bed reactor, specifically comprising the following steps:

[0092] (1) A catalyst and wax are brought into contact in an off-site filling container for wax coating treatment to obtain a wax-coated catalyst; wherein the weight ratio of the catalyst to the wax is 1:0.3; the off-site filling container is a container with a stirring function; the mixing conditions include: a temperature of 80° C., a stirring speed of 80 rpm, and a mixing time of 50 minutes; an operating pressure of 0.4 MPa; and an inert atmosphere in the off-site filling container.

[0093] (2) After the wax coating is completed, the wax-coated catalyst is loaded into the reactor through a metal hose. At the same time, 0.5 times the amount of dry ice as the catalyst (the weight ratio of catalyst to dry ice is 1:0.5) and 2 times / hour of nitrogen gas as the total volume of the reactor are added to the reactor through a dry ice interface. The filling temperature in the reactor is 35°C. During the filling process, the temperature rise in the fixed bed reactor is controlled to be below 3°C. The pressure in the reactor is 0.4MPa. The introduction rate of the wax-coated catalyst is 200Kg / min, and the introduction rate of solid carbon dioxide is 200Kg / min.

[0094] The above process is followed to complete the loading of one layer of catalyst; the reactor of this embodiment is loaded with 2 layers in total.

[0095] After the filling is completed, the reactor is closed until the reaction material is fed to carry out the reaction performance test. The specific process is the same as that in Example 1.

[0096] Example 3

[0097] use Figure 1 The loading system shown in the figure performs oxygen-free loading of catalyst in a fixed bed reactor, specifically comprising the following steps:

[0098] (1) A catalyst and wax are brought into contact in an off-site filling container for wax coating treatment to obtain a wax-coated catalyst; wherein the weight ratio of the catalyst to the wax is 1:20; the off-site filling container is a container with a stirring function; the mixing conditions include: a temperature of 400° C., a stirring speed of 5 rpm, and a mixing time of 250 minutes; an operating pressure of 0.05 MPa; and an inert atmosphere in the off-site filling container.

[0099] (2) After the wax coating is completed, the wax-coated catalyst is loaded into the reactor through a metal hose. At the same time, 0.05 times the amount of dry ice as the catalyst (the weight ratio of the catalyst to the dry ice is 1:0.05) and 0.05 times / hour of the total volume of the reactor nitrogen are added to the reactor through the dry ice interface. The filling temperature in the reactor is -40°C. During the filling process, the temperature rise in the fixed bed reactor is controlled to be below 8°C. The pressure in the reactor is 0.05MPa. The introduction rate of the wax-coated catalyst is 1500Kg / min, and the introduction rate of solid carbon dioxide is 750Kg / min.

[0100] The above process is followed to complete the loading of one layer of catalyst; the reactor of this embodiment is loaded with 2 layers in total.

[0101] After the filling is completed, the reactor is closed until the reaction material is fed to carry out the reaction performance test. The specific process is the same as that in Example 1.

[0102] Example 4

[0103] This embodiment refers to the method of embodiment 1, and the difference from embodiment 1 is that:

[0104] During the catalyst loading process, no inert gas was introduced into the fixed bed reactor; the remaining processes and conditions were the same as those in Example 1. After the loading was completed, the reactor was closed until the reaction material was fed to perform the reaction performance test, and the specific process was the same as in Example 1.

[0105] Example 5

[0106] This example refers to the method of Example 1, and the difference from Example 1 is that: the catalyst and wax are contacted in an external filling container under the following conditions for wax coating treatment to obtain a wax-coated catalyst; wherein the weight ratio of the catalyst to the wax is 1:5; the external filling container is a container with a stirring function; the mixing conditions include: a temperature of 240°C, a stirring speed of 10 rpm, and a mixing time of 100 minutes; an operating pressure of 1.0 MPa; and an inert atmosphere in the external filling container. The remaining processes and conditions are the same as those in Example 1. After the filling is completed, the reactor is closed until the reaction material is fed for reaction performance testing, and the specific process is the same as in Example 1.

[0107] Example 6

[0108] This embodiment refers to the method of embodiment 1, and the difference from embodiment 1 is that: step (2) is carried out according to the following conditions. After the wax coating is completed, the wax-coated catalyst is loaded into the reactor through a metal hose. At the same time, the reactor is supplemented with 20 times the amount of catalyst dry ice (the weight ratio of catalyst to dry ice is 1:20) and 0.5 times / hour of the total volume of the reactor nitrogen through the dry ice interface. The filling temperature in the reactor is 60°C. During the filling process, the temperature rise in the fixed bed reactor is controlled to be below 5°C. The pressure in the reactor is 1.0MPa, the introduction rate of the wax-coated catalyst is 300Kg / min, and the introduction rate of solid carbon dioxide is 1.0Kg / min. After the filling is completed, the reactor is closed until the reaction is fed to carry out the reaction performance test. The specific process is the same as that in embodiment 1.

[0109] Comparative Examples 1 to 3

[0110] This comparative example is used to illustrate the catalytic performance of the prepared propylene catalyst after contact with air in a small evaluation device.

[0111] The prepared propylene catalyst was loaded into a 10 ml evaluation device, and after being exposed to air for 0 min (Comparative Example 1), 60 min (Comparative Example 2), and 120 min (Comparative Example 3), nitrogen was purged, and the propylene raw material was preheated and sent to a fixed bed reactor for dimerization to generate 4-methyl-1-pentene. The reaction conditions were temperature 155°C, pressure 7 MPa, and space velocity 0.6 h -1 The materials at the reactor outlet enter the online chromatograph for composition analysis to obtain propylene conversion rate data.

[0112] Comparative Example 4

[0113] Use attached Figure 2 The fixed bed reactor shown has two beds arranged in the reactor, wherein the inner diameter of the reactor is 3000 mm, the height is 6500 mm, and the catalyst loading height of the single bed is 2000 mm.

[0114] The catalyst was exposed to air and loaded into a fixed bed reactor by a bag method. After nitrogen purging, propylene was introduced to start propylene dimerization reaction. After loading, the reactor was closed until the reaction was fed to perform a reaction performance test. The specific process was the same as that in Example 1. When the reaction was stable for 2 hours, the material at the reactor outlet was fed into an online chromatograph for composition analysis to obtain propylene conversion data of the loaded catalyst under an aerobic environment.

[0115] The propylene conversion data obtained in the above comparative examples 1 to 3 are listed in the following table 1. The propylene conversion data obtained in the examples and comparative example 4 are listed in the following table 2.

[0116] Table 1

[0117] Comparative Example 1 Comparative Example 2 Comparative Example 3 Catalyst in aerobic environment time / min 0 60 120 Propylene conversion rate / % 85 40 10

[0118] Table 2

[0119] Propylene conversion rate / % Example 1 86 Comparative Example 4 10 Example 2 84 Example 3 62 Example 4 71 Example 5 78 Example 6 76

[0120] According to the data in Table 1 above, it can be seen that when not in contact with air, the propylene catalyst can achieve a propylene conversion rate of 85%; as the contact time between the catalyst and air increases, the propylene conversion rate decreases accordingly.

[0121] According to the data in Table 2 above, the propylene conversion rate of the reactor loaded with catalyst under aerobic environment in Comparative Example 4 is only 10%, indicating that the catalyst has been seriously deactivated and its life span has been reduced, and it cannot meet the process requirements of long-term operation.

[0122] Example 1 adopts the anaerobic filling method and system provided in the present application, and the propylene conversion rate obtained is 86%, which is close to the propylene conversion rate obtained in the evaluation device of Comparative Example 1 (without contact with air), and slightly higher than the effect obtained in Comparative Example 1, indicating that the method provided in the present application achieves the effect of anaerobic filling, the catalyst life can meet the use requirements, and can meet the process requirements of long-term operation.

[0123] Comparing Example 1 with Example 3, it can be seen that Example 1 adopts the mixing conditions and catalyst loading conditions provided by the present disclosure, and the propylene conversion rate of the fixed bed reactor after loading in Example 1 is higher, achieving the effect of anaerobic loading.

[0124] Comparing Example 1 with Example 4, it can be seen that Example 1 supplements inert gas during the catalyst loading process. The propylene conversion rate of the fixed bed reactor after loading in Example 1 is higher, and the effect of anaerobic loading is achieved.

[0125] Comparing Example 1 with Example 5 and Example 6, it can be seen that the conditions for wax coating of the catalyst and wax in an external loading container and the conditions for catalyst loading in a fixed bed reactor in Example 1 are both within the optimized process conditions. Compared with Example 5 (the conditions for wax coating in an external loading container were not optimized) and Example 6 (the conditions for catalyst loading were not optimized), the propylene conversion rate in the loaded reactor in Example 1 is the best.

[0126] The preferred embodiments of the present disclosure are described in detail above; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0127] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0128] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A method for anaerobic loading of a catalyst in a fixed bed reactor, characterized in that: The following steps are involved: S1, contacting the catalyst with wax in an external filling container to perform wax coating treatment to obtain a wax-coated catalyst; S2, allowing the wax-coated catalyst and solid carbon dioxide to enter a fixed bed reactor for oxygen-free loading of the catalyst.

2. The method according to claim 1, characterized in that The weight ratio of the catalyst to the wax added to the external filling container is 1:(0.001-10), preferably 1:(0.01-1); Preferably, the wax is selected from paraffin wax and / or microcrystalline wax, the bromine index of the wax is less than 100 mgBr / 100 g, and the melting point of the wax is greater than 45°C.

3. The method according to claim 1, characterized in that In step S1, the external filling container is a container with a stirring function; the conditions for the wax coating treatment include: a temperature of 60 to 350°C, preferably 80 to 150°C; a stirring speed of 10 to 200 rpm, preferably 30 to 100 rpm; a mixing time of 1 to 200 minutes, preferably 5 to 60 minutes; an operating pressure of 0.1 to 5 MPa, preferably 0.1 to 0.5 MPa; and an inert atmosphere in the external filling container.

4. The method according to claim 1, characterized in that: Step S2 includes: introducing the wax-coated catalyst into a fixed bed reactor, and simultaneously introducing solid carbon dioxide into the fixed bed reactor, so that the wax-coated catalyst is in contact with the solid carbon dioxide; Optionally, step S2 further comprises: during the anaerobic loading of the catalyst, introducing one or more of an inert gas or a carbon dioxide gas into the fixed bed reactor.

5. The method according to claim 1, characterized in that The conditions for loading the catalyst in step S2 include: a weight ratio of solid carbon dioxide to catalyst of (0.01 to 100):1, preferably (0.05 to 1):1; an operating temperature of -30 to 100°C, preferably 0 to 40°C, a temperature rise of 5°C or less in the fixed bed reactor during loading, preferably a temperature rise of 1°C or less; a pressure of 0.1 to 5MPa, preferably 0.1 to 0.5MPa; an introduction rate of the wax-coated catalyst of 1 to 1000Kg / min, preferably 5 to 200Kg / min; and an introduction rate of solid carbon dioxide of 0.01 to 10000Kg / min, preferably 2.5 to 500Kg / min.

6. The method according to claim 4, characterized in that The amount of inert gas supplemented per hour is 0.1 to 10 times the total volume of the fixed bed reactor; preferably, the amount of inert gas supplemented per hour is 1 to 5 times the total volume of the fixed bed reactor; Optionally, the inert gas is selected from one or more of nitrogen, argon and helium; the oxygen content of the inert gas is less than 10 ppm, preferably less than 3 ppm; the water content is less than 10 ppm, preferably less than 3 ppm.

7. The method according to claim 4, characterized in that The method includes: Loading the catalyst layer by layer from bottom to top in the fixed bed reactor; Preferably, the steps include: During the loading process of each layer of catalyst, a grid support plate is first set in the fixed bed reactor and large and small ceramic balls are loaded; then the wax-coated catalyst is introduced into the fixed bed reactor through a loading tube, solid carbon dioxide is introduced through a solid carbon dioxide supplementary inlet at the top of the fixed bed reactor, and inert gas is introduced through an inert gas inlet at the bottom of the fixed bed reactor.

8. The method according to claim 1, characterized in that: The catalyst contains an active metal component; preferably, the active metal is selected from one or more of sodium, potassium, lithium, magnesium, aluminum and iron; Optionally, the catalyst includes a catalyst for preparing 4-methyl-1-pentene by propylene dimerization.

9. A system for loading catalyst in a fixed bed reactor without oxygen, characterized in that: The system comprises an external loading container and a fixed bed reactor; the external loading container comprises a catalyst inlet, a wax inlet and a wax-coated catalyst outlet; The fixed bed reactor comprises a wax-coated catalyst inlet and a solid carbon dioxide inlet; the wax-coated catalyst outlet of the external filling container is connected to the wax-coated catalyst inlet of the fixed bed reactor through a filling pipe; The external filling container is configured such that the catalyst and the wax are contacted in the external filling container to be wax-coated to obtain a wax-coated catalyst; The fixed bed reactor is configured to allow the wax-coated catalyst and solid carbon dioxide to enter the fixed bed reactor for oxygen-free loading of the catalyst.

10. The system according to claim 9, characterized in that The external filling container includes one of a catalyst kettle, a circular hopper and a square hopper; preferably, the external filling container is a catalyst kettle with a stirrer; the wax-coated catalyst outlet is provided at the lower part of the external filling container; Optionally, the diameter of the filling tube is 50 to 300 mm; Optionally, the filling tube is selected from a cloth bag or a metal hose; Preferably, the fixed bed reactor further comprises an inert gas inlet for replenishing inert gas during the catalyst loading process.

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