CN109277108B

CN109277108B - Silicon-containing hydrodemetallization catalyst and preparation method and application thereof

Info

Publication number: CN109277108B
Application number: CN201710595286.6A
Authority: CN
Inventors: 任靖; 张勇; 李顺新; 宋春利; 姜艳
Original assignee: China Petroleum and Chemical Corp; Sinopec Catalyst Co
Current assignee: China Petroleum and Chemical Corp; Sinopec Catalyst Co
Priority date: 2017-07-20
Filing date: 2017-07-20
Publication date: 2021-07-27
Anticipated expiration: 2037-07-20
Also published as: CN109277108A

Abstract

The invention relates to the field of catalyst preparation, and discloses a preparation method of a silicon-containing hydrogenation demetallization catalyst, which comprises the following steps of (1) carrying out first contact on a first silicon-containing solution and a first physical pore-enlarging agent, and carrying out second contact on a second silicon-containing solution and a second physical pore-enlarging agent; (2) mixing the contacted first physical pore-enlarging agent and the contacted second physical pore-enlarging agent obtained in the step (1) with pseudo-boehmite, forming, first drying and first roasting to obtain a silicon-containing alumina carrier; (3) and (3) carrying out third contact on the hydrogenation active component impregnation liquid and the silicon-containing alumina carrier obtained in the step (2), and carrying out second drying and second roasting on the contacted silicon-containing alumina carrier to obtain the silicon-containing hydrogenation demetalization catalyst. The catalyst prepared by the method has higher mechanical strength, proper pore structure, moderate action of active components and a carrier, and higher hydrodemetallization activity and activity stability.

Description

Silicon-containing hydrodemetallization catalyst and preparation method and application thereof

Technical Field

The invention relates to the field of catalyst preparation, in particular to a preparation method of a silicon-containing hydrodemetallization catalyst.

Background

With the improvement of the deep processing requirement of raw materials in the world, the main energy structure gradually develops towards macromolecules and high carbon, especially for China with the general heavy crude oil. In order to effectively solve the problems of catalyst activity reduction or inactivation and the like caused by overlarge diffusion resistance of heavy oil components in catalyst pore channels, heavy metal impurity deposition and coking, the alumina carrier widely used in the industries of petrochemical industry and the like is urgently required to have the characteristics of large pore volume and large pore diameter. The large pore size is favorable for macromolecular compounds to diffuse into the catalyst particles, and the large pore volume is favorable for improving the metal or coke capacity.

US4448896 discloses a process for preparing a residual oil hydrodemetallization catalyst, which comprises at least one group viii and/or group vib metal element as an active component, supported on a large pore alumina carrier. The preparation method of the residual oil hydrodemetallization catalyst comprises the steps of uniformly mixing and kneading pseudo-boehmite and carbon black powder, forming, drying, roasting in an oxygen-containing atmosphere to prepare an alumina carrier, then impregnating VIII-family and VIB-family active metal components on the carrier, or uniformly mixing and kneading the pseudo-boehmite, the carbon black powder and a compound containing the VIII-family and VIB-family active metal components, forming, drying, and roasting in an oxygen-containing atmosphere to prepare the hydrodemetallization catalyst. The method takes carbon black powder as a physical pore-enlarging agent to improve the content of macropores of the catalyst, but the mechanical strength of the catalyst needs to be further improved.

CN1160602A discloses a large-aperture alumina carrier and a preparation method thereof. The preparation process includes mixing pseudoboehmite with physical pore-enlarging agent such as carbon black and chemical pore-enlarging agent such as phosphide, kneading, forming, drying and roasting to obtain alumina carrier. The method can overcome the defects of using a physical pore-expanding agent and a chemical pore-expanding agent separately, but the mechanical strength of the carrier needs to be further improved.

CN1206037A discloses a residual oil hydrodemetallization catalyst and a preparation method thereof, wherein the catalyst takes VIII group and/or VIB group metal elements as active components and is loaded on a large-aperture alumina carrier. The preparation method of the residual oil hydrodemetallization catalyst comprises the steps of adding carbon black powder with the particle size of 30 microns as a physical pore-expanding agent and a chemical pore-expanding agent containing a phosphorus, silicon or boron compound and capable of chemically reacting with pseudo-boehmite or alumina in the kneading process of the pseudo-boehmite, kneading the mixture into a plastic body, extruding the plastic body into strips, forming, drying and roasting to obtain a carrier, loading active components onto the carrier in a spray impregnation mode, and drying and roasting to obtain the catalyst.

In summary, in the prior art, a physical pore-enlarging agent is usually used to increase the pore diameter of the carrier in the process of preparing the macroporous alumina carrier and/or the hydrodemetallization catalyst, and the addition of the physical pore-enlarging agent can actually increase the content of macropores in the alumina carrier, but can adversely affect the mechanical strength of the carrier and the catalyst. In addition, the interaction between the active component and the carrier needs to be further improved in the current preparation process of the catalyst.

Disclosure of Invention

The invention aims to overcome the problems in the prior art and provides a preparation method of a silicon-containing hydrodemetallization catalyst, the catalyst prepared by the method has higher mechanical strength and proper pore structure, the active component and the carrier have moderate action, and the catalyst has higher hydrodemetallization activity and activity stability.

In order to achieve the above objects, in one aspect, the present invention provides a method for preparing a silicon-containing hydrodemetallization catalyst, the method comprising the steps of,

(1) carrying out first contact on the first silicon-containing solution and a first physical pore-enlarging agent, and carrying out second contact on the second silicon-containing solution and a second physical pore-enlarging agent;

(2) mixing the contacted first physical pore-enlarging agent and the contacted second physical pore-enlarging agent obtained in the step (1) with pseudo-boehmite, forming, first drying and first roasting to obtain a silicon-containing alumina carrier;

(3) carrying out third contact on the hydrogenation active component impregnation liquid and the silicon-containing alumina carrier obtained in the step (2), and carrying out second drying and second roasting on the contacted silicon-containing alumina carrier to obtain a silicon-containing hydrogenation demetalization catalyst;

wherein, the first silicon-containing solution and the second silicon-containing solution both contain silicate ester, the particle size of the first physical pore-enlarging agent is 100-540 meshes, and the particle size of the second physical pore-enlarging agent is 900-2000 meshes.

Preferably, the method further comprises the steps of: (4) and (4) carrying out sealing heat treatment and third drying treatment on the silicon-containing hydrodemetallization catalyst obtained in the step (3).

More preferably, the sealing heat treatment is performed in a mixed atmosphere of ammonia gas and water vapor.

More preferably, the conditions of the sealing heat treatment include: the gas pressure is 3-5MPa, the partial pressure of ammonia gas is 30-50%, the rest is water vapor, the heat treatment temperature is 100-150 ℃, and the treatment time is 5-10 hours.

More preferably, said third drying conditions comprise: the temperature is 80-120 ℃ and the time is 6-10 hours.

Preferably, the first physical pore-expanding agent and the second physical pore-expanding agent are respectively selected from one or more of carbon black powder, charcoal or wood dust; more preferably, the first physical pore-expanding agent and the second physical pore-expanding agent are both carbon black powder; more preferably, the weight ratio of the first physical pore-enlarging agent to the second physical pore-enlarging agent is 2-3: 1, more preferably 2.5 to 3: 1. more preferably, the first physical pore-expanding agent is added in an amount of 10 to 15 wt% based on the dry weight of alumina; more preferably, the second physical pore-expanding agent is added in an amount of 5 to 10 wt% based on the dry basis of alumina.

More preferably, the solvents of the first and second silicon-containing solutions are respectively selected from one or more of ethanol, methanol and acetone;

more preferably, the silicate is a fatty alcohol orthosilicate and/or a fatty alcohol metasilicate;

more preferably, the silicate is one or more of methyl orthosilicate, ethyl orthosilicate, propyl orthosilicate, and butyl orthosilicate.

Preferably, the dosage ratio of the first silicon-containing solution to the second silicon-containing solution is 2-12: 1. more preferably, the combined amount of the first and second silicon containing solutions is from 2.5 to 7 wt.% on a dry basis of alumina, calculated as silica.

Preferably, the volume of the first silicon-containing solution is 30-50% of the saturated water absorption capacity of the first physical pore-enlarging agent. Preferably, the volume of the second silicon-containing solution is the saturated water absorption capacity of the second physical pore-enlarging agent.

Preferably, extrusion aids and/or peptizers are also added during mixing in step (2).

Preferably, the conditions of the first drying include: the temperature is 100 ℃ and 130 ℃, and the time is 1-10 hours; more preferably, the first firing comprises: firstly, roasting in a nitrogen atmosphere, and then roasting in an air atmosphere; more preferably, the roasting temperature under the nitrogen atmosphere is 400-600 ℃, the roasting time is 4-6 hours, the roasting temperature under the air atmosphere is 600-900 ℃, and the roasting time is 4-8 hours.

Preferably, the hydrogenation active component impregnation liquid contains metals of VIB group and VIII group. More preferably, the group VIB metal content, calculated as oxide, is from 7 to 15g/100mL and the group VIII metal content, calculated as oxide, is from 0.8 to 3g/100 mL.

In a second aspect, the present invention provides a silicon-containing hydrodemetallization catalyst prepared by the above method.

The second aspect of the present invention provides an application of the silicon-containing hydrodemetallization catalyst in a hydrodemetallization reaction.

According to the technical scheme, the silicon dioxide precursor is soaked into two physical pore expanding agents with different particle sizes, the soaked physical pore expanding agents and the pseudo-boehmite are kneaded and molded, the molded object is firstly roasted in a nitrogen atmosphere, then the molded object is roasted in an air atmosphere to prepare the silicon-containing alumina carrier, and then the active component is soaked to prepare the silicon-containing hydrodemetallization catalyst. When the silicon dioxide is roasted in the nitrogen atmosphere, the silicon dioxide and the aluminum oxide on the surface act to combine to form the composite oxide. When the physical pore-expanding agent is baked in the air atmosphere, the physical pore-expanding agent is oxidized and removed. On one hand, the silicon dioxide plays a role in supporting a framework, and on the other hand, the carbon deposition resistance and sintering resistance of the catalyst are improved, so that the silicon-containing hydrodemetallization catalyst with good mechanical property, pore structure and catalytic effect is obtained. Meanwhile, the gas formed during oxidation of the physical pore-expanding agent can play a good role in pore expansion, and the physical pore-expanding agents with different particle sizes can be selected to effectively adjust the pore structure of the carrier.

Further, the present application makes the degree of impregnation of the silica precursor different in the two physical pore-enlarging agents of different particle sizes, ensuring that the first physical pore-enlarging agent of larger particle size is not completely impregnated, and the second physical pore-enlarging agent of smaller particle size is completely impregnated. Through the technical scheme, a silicon dioxide shell layer is formed in the first physical pore-expanding agent, so that a good framework supporting effect is achieved, collapse of macropores is prevented, and mass transfer and diffusion of reactants (such as residual oil molecules) are facilitated through corresponding pore channels; in the second physical pore-enlarging agent, the silicon dioxide is loaded on the contact surface of the second physical pore-enlarging agent and the alumina carrier and interacts with the alumina, and due to the existence of the silicon dioxide, the acidity of the obtained pore-site carrier is reduced, the carbon deposition resistance and sintering resistance of the corresponding catalyst are improved, and the service life of the catalyst is prolonged.

Further, the catalyst impregnated with the active component is subjected to heat treatment in the mixed atmosphere of ammonia gas and water vapor, and the active component on the surface of the carrier is dissolved and redispersed under the action of the mixed atmosphere, so that the action between the active component and the carrier is changed, and the dispersion degree of the active component is improved. In addition, under the condition of ammonia and water vapor sealing heat treatment, alumina crystal grains have hydration and regrowth effects, the aperture of the catalyst is improved, and the finally obtained catalyst has higher activity and activity stability.

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

The preparation method of the silicon-containing hydrodemetallization catalyst comprises the following steps,

(3) carrying out third contact on the hydrogenation active component impregnation liquid and the silicon-containing alumina carrier obtained in the step (2), and carrying out second drying and second roasting on the contacted silicon-containing alumina carrier to obtain a silicon-containing hydrogenation demetalization catalyst; wherein, the first silicon-containing solution and the second silicon-containing solution both contain silicate ester, the particle size of the first physical pore-enlarging agent is 100-540 meshes, and the particle size of the second physical pore-enlarging agent is 900-2000 meshes.

According to the invention, the first physical pore-expanding agent and the second physical pore-expanding agent are not particularly limited, and can play a pore-expanding effect in the preparation process of the silicon-containing alumina carrier. The first physical pore-expanding agent and the second physical pore-expanding agent are respectively selected from one or more of carbon black powder, charcoal or wood chips in view of improving the specific surface area and pore volume of the obtained siliceous alumina carrier. In view of fully absorbing the silicon-containing solution and facilitating control of the pore structure of the obtained silicon-containing alumina carrier, the first physical pore-enlarging agent and the second physical pore-enlarging agent are preferably both carbon black powder. From the viewpoint of obtaining pores with different sizes, it is preferable that the particle size of the first physical pore-enlarging agent is 200-.

According to the invention, the dosage of the first physical pore-expanding agent and the second physical pore-expanding agent is determined according to the property of the silicon-containing alumina carrier to be obtained. In order to improve the specific surface area, the pore volume and the like of the siliceous alumina carrier and obtain the siliceous alumina carrier with good performance, the weight ratio of the first physical pore-expanding agent to the second physical pore-expanding agent is preferably 2-3: 1, more preferably 2.5 to 3: 1.

in order to adjust the properties of the obtained siliceous alumina carrier according to the present invention, it is preferable that the first physical pore-expanding agent is added in an amount of 10 to 15 wt%, more preferably 12 to 14 wt%, based on the dry weight of alumina; more preferably, the second physical pore-expanding agent is added in an amount of 5 to 10 wt%, and still more preferably 6 to 9 wt% based on the dry weight of alumina.

In the present invention, the alumina dry basis refers to pseudo-boehmite calculated as alumina, which corresponds to alumina in the finally obtained silica-containing alumina carrier.

According to the present invention, the silicate is contacted with the physical pore-enlarging agent in the form of the first silicon-containing solution and the second silicon-containing solution, with the object of uniformly contacting the silicate with the physical pore-enlarging agent and sufficiently immersing the silicate into the interior of the physical pore-enlarging agent. From the aspect of facilitating the contact operation, it is preferable that the solvents of the first silicon-containing solution and the second silicon-containing solution are respectively selected from one or more of ethanol, methanol, and acetone, and ethanol is preferable.

According to the present invention, the silicate is not particularly limited, and preferably, the silicate is a fatty alcohol orthosilicate and/or a fatty alcohol metasilicate. The aliphatic group in the aliphatic orthosilicic acid ester and the aliphatic metasilicate ester may be an aliphatic group having from about C1 to about C6, such as methyl, ethyl, propyl (e.g., n-propyl, isopropyl), butyl (e.g., n-butyl, t-butyl, sec-butyl), pentyl (e.g., n-pentyl, isopentyl, neopentyl), hexyl (e.g., n-hexyl, 2-methylpentyl, 3-methylpentyl, 2-dimethylbutyl, 2, 3-dimethylbutyl, etc.). Preferably, the silicate is one or more of methyl orthosilicate, ethyl orthosilicate, propyl orthosilicate and butyl orthosilicate.

In the present invention, the form of the first contact and the second contact is not particularly limited, and may be selected as needed, and may be, for example, immersion, spraying, misting, or the like, as long as the physical pore-expanding agent absorbs the silicon-containing solution. In order to ensure that the surface of the physical pore-expanding agent is uniformly impregnated with the silicon-containing solution, the silicon-containing solution can be uniformly contacted in the impregnation process in a manner of auxiliary stirring, rotation and the like. Specifically, the solution may be atomized and then sprayed into a physical pore-enlarging agent that continuously rotates, and the atomization may be performed by means of a nozzle, ultrasonic waves, high-speed air flow, and the like, for example, a rotating pan, a sugar-coating machine, and the like.

According to the invention, in the contact process of the silicon-containing solution and the physical pore-enlarging agent, the dosage of the silicon-containing solution can be determined according to the requirement and can be above the saturated water absorption capacity of the physical pore-enlarging agent, namely, the physical pore-enlarging agent fully absorbs the silicon-containing solution to reach saturation (hereinafter also referred to as saturated impregnation); or less than the saturated water absorption of the physical pore-expanding agent, i.e., the silicon-containing solution is impregnated into only a portion of the internal pores of the physical pore-expanding agent (hereinafter also referred to as unsaturated impregnation). In the latter case, in order to uniformly contact the silicon-containing solution with all the physical pore-expanding agent particles, the silicon-containing solution is preferably added to the physical pore-expanding agent under stirring, rotation, or the like, and more preferably, the above contact is performed by spraying, atomizing, or the like, for example. By the contact mode, the silicon-containing solution fully enters the pores of the physical pore-expanding agent; when the usage amount of the silicon-containing solution is less than the saturated water absorption amount of the physical pore-enlarging agent, the silicon-containing solution can only enter the outer layer of the physical pore-enlarging agent and does not enter the inner core part of the physical pore-enlarging agent, so that the silicon dioxide shell is obtained by roasting.

According to a preferred embodiment of the present invention, in order to obtain a silica-containing alumina catalyst having a good pore distribution, the first and second silicon-containing solutions are used in a ratio of 2 to 12: 1, preferably 4 to 10: 1.

according to a preferred embodiment of the present invention, in order to obtain a siliceous alumina catalyst having good mechanical strength, the first siliceous solution and the second siliceous solution are used in a total amount of 2.5 to 7% by weight, preferably 3 to 6% by weight, based on the silica, of alumina on a dry basis.

According to a preferred embodiment of the present invention, in order to form the silica shell layer by the first physical pore-expanding agent, the first physical pore-expanding agent is subjected to unsaturated impregnation. More preferably, the volume of the first silicon-containing solution is 30-50%, more preferably 30-40% of the saturated water absorption capacity of the first physical pore-enlarging agent.

According to the present invention, the second physical pore-expanding agent may be subjected to unsaturated impregnation or saturated impregnation. In order to sufficiently form pores by the second physical pore-enlarging agent, the volume of the second silicon-containing solution is 80% or more, more preferably 90% or more, and still more preferably 100% of the saturated water absorption capacity of the second physical pore-enlarging agent.

According to the present invention, the pseudoboehmite added in the preparation of the silicon-containing alumina carrier is not particularly limited, and may be a pseudoboehmite conventionally used in the preparation of an alumina carrier in the art, a commercially available product, or may be prepared by a conventional method.

According to the invention, extrusion aids can also be added during mixing in step (2). As the extrusion aid, an extrusion aid used in the preparation of an alumina carrier conventionally used in the art can be used, and can be one or more selected from sesbania powder, starch and methylcellulose, and sesbania powder is preferred. Preferably, the extrusion aid is added in an amount of 3 to 5 wt%, preferably 4 to 5 wt%, of the alumina dry basis.

According to the present invention, a peptizing agent may also be added during the mixing in step (2). As the peptizing agent, there may be used a peptizing agent conventionally used in the art for preparing an alumina support, and there may be one or more selected from formic acid, acetic acid, citric acid, and nitric acid. The amount of the peptizing agent added can be determined according to the desired molding effect. Preferably, the peptizing agent is added in an amount of 3 to 10 wt.%, preferably 5 to 7 wt.%, of the alumina dry basis. In order to facilitate the mixing of the peptizing agent, the peptizing agent may be diluted with an appropriate solvent and then mixed with other materials, for example, water may be used for dilution.

In the invention, the first physical pore-enlarging agent, the contacted second physical pore-enlarging agent and the pseudo-boehmite can be used for preparing the silicon-containing alumina carrier by the existing method for preparing the alumina carrier, and can be specifically obtained by mixing, molding, first drying and first roasting in sequence.

The mixing can be carried out by using the existing equipment which can be used for mixing materials, such as a mixer, a stirrer and the like, and the mixing conditions are not particularly limited, so that the aim of uniform mixing can be fulfilled.

The forming can be carried out by adopting the existing equipment which can be used for forming the carrier, such as a bar extruder, a tablet press and the like, and the shape of the carrier can be specifically selected according to the requirement.

The conditions for the first drying are not particularly limited, and the molded raw material may be dried. For example, the first drying conditions may include: the temperature is 100-130 ℃ and the time is 1-10 hours, preferably, the temperature is 110-120 ℃ and the time is 4-6 hours.

As the conditions of the first firing, there may be included: the firing is performed in a nitrogen atmosphere and then in an air atmosphere. Specifically, the roasting temperature under the nitrogen atmosphere is 400-600 ℃, and preferably 450-500 ℃; the time is 4 to 6 hours, preferably 5 to 6 hours. The roasting temperature under the air atmosphere is 600-900 ℃, and preferably 700-800 ℃; the time is 4 to 8 hours, preferably 5 to 7 hours.

The first firing may be performed in a tube furnace, and the entire tube furnace may be filled with a firing atmosphere before the first firing, but other suitable equipment capable of performing the firing operation may be selected.

According to the present invention, in the step (3), the hydrogenation active component impregnation solution is not particularly limited, and may be prepared according to a target catalyst composition. The hydrogenation active component in the hydrogenation active component impregnating solution can contain metals of VIB group and VIII group. As the group VIB metal, one or more selected from Cr, Mo and W; as the group VIII metal, one or more selected from Fe, Co, Ni, Ru, Rh, Pd, Os, Ir and Pt may be used. Among them, the group VIB metal is preferably Mo and/or W, and the group VIII metal is preferably Co and/or Ni.

In the hydrogenation active component impregnation liquid, the hydrogenation active component can be added in proper concentration, for example, the content of the VIB group metal calculated by oxide is 7-15g/100mL, the content of the VIII group metal calculated by oxide is 0.8-3g/100mL, preferably, the content of the VIB group metal calculated by oxide is 8-12g/100mL, and the content of the VIII group metal calculated by oxide is 1-2g/100 mL. As the oxide of the above-mentioned group VIB metal or group VIII metal, specifically, the oxide of Mo means MoO₃The oxide of Cr means CrO₃The oxide of W means WO₃The oxide of Ni means NiO, the oxide of Fe means FeO, the oxide of Co means CoO, the oxide of Ru means RuO₂The oxide of Rh means Rh₂O₃Oxidation of PdPdO as oxide of Os, Oso as oxide of Os₄The oxide of Ir means IrO₂Oxide of Pt means PtO₂。

In the present invention, the mode of the third contact is not particularly limited, and may be selected as needed, and for example, immersion, spraying, or the like may be used, and the immersion mode is preferably used.

As the conditions of the second drying, there may be included: the temperature is 80-120 ℃, and the time is 6-10 hours; preferably, the temperature is 90-110 ℃ and the time is 6-8 hours.

The temperature is 400-600 ℃ and the time is 3-6 hours as the conditions of the second roasting; preferably, the temperature is 450 ℃ and 550 ℃ and the time is 4-6 hours.

According to a more preferred embodiment of the present invention, in order to further improve the pore structure of the silica-containing alumina support, the method further comprises the steps of: (4) and (4) carrying out sealing heat treatment and third drying treatment on the silicon-containing hydrodemetallization catalyst obtained in the step (3). More preferably, the sealing heat treatment is performed in a mixed atmosphere of ammonia gas and water vapor. By carrying out closed heat treatment in the mixed atmosphere of ammonia and water vapor, the crystal grain of the silicon-containing alumina carrier can be further enlarged, the aperture of the carrier is enlarged, the interaction between the metal active component and the carrier can be improved, and the final catalyst has higher activity and activity stability.

Specifically, the conditions for the sealing heat treatment may include: the gas pressure is 3-5MPa, the partial pressure of ammonia gas is 30-50%, the rest is water vapor, the heat treatment temperature is 100-150 ℃, and the treatment time is 5-10 hours.

The conditions of the third drying are not particularly limited, and examples thereof include: the temperature is 80-120 deg.C and the time is 6-10 hr, preferably 90-110 deg.C and the time is 8-10 hr.

The invention also provides the silicon-containing hydrodemetallization catalyst prepared by the method.

The invention also provides the application of the silicon-containing hydrodemetallization catalyst in hydrodemetallization reaction, such as residual oil hydrodemetallization reaction.

The present invention will be described in detail below by way of examples. In the following examples, the carbon black powder is activated carbon powder obtained by pulverizing and sieving coconut shell activated carbon produced by Tianjin red dragon water purification material science and technology limited.

Using N₂The physical adsorption-desorption method is used for representing the pore structures of the alumina carriers obtained in the following examples and comparative examples, and ASAP-2420 type N is adopted₂Physical adsorption-desorption instrument. The specific operation is as follows: a small amount of samples are taken to be treated for 3 to 4 hours in vacuum at the temperature of 300 ℃, and finally, the product is placed under the condition of liquid nitrogen low temperature (-200 ℃) to be subjected to nitrogen absorption-desorption test. Wherein the surface area is obtained according to the BET equation and the pore size distribution and pore volume are obtained according to the BJH model.

The alumina support components obtained in the examples and comparative examples were characterized by X-ray fluorescence spectroscopy (XRF) by the following procedure: the performance index of the ZSX-100e type X-ray fluorescence spectrometer manufactured by RIGAKU company of Japan is as follows: x-ray tube Be window thickness: 30 mu m; power: 4 kW; output voltage: 20-60 kV; output current: 2-150 mA; 2 θ angle reproducibility 0.0001 °; the 2 theta angle accuracy is 0.0002 deg..

Example 1

1) Weighing 15g of first carbon black powder with the particle size of 400 meshes, placing the first carbon black powder into a spraying rolling pot, and spraying 7.5mL (the using amount is 50 percent of the saturated water absorption amount of the first carbon black powder, wherein the using amount is equivalent to 4 g of silicon dioxide) of ethyl orthosilicate ethanol solution to the first carbon black powder in an unsaturated dipping mode by using a nozzle atomization mode under the rotation state of 90 r/min.

2) 5g of second carbon black powder with the particle size of 1300 meshes is weighed and placed in a spraying rolling pot, and 5mL of ethyl orthosilicate ethanol solution (the amount is the saturated water absorption amount of the second carbon black powder, which is equivalent to 0.5 g of silicon dioxide) is sprayed and soaked in the second carbon black powder in a saturated soaking mode in an atomizing mode under the rotation state of 90 r/min.

3) Fully mixing the first carbon black powder obtained in the step 1) and the second carbon black powder obtained in the step 2) with 150 g of pseudo-boehmite (produced by Wenzhou refined crystal alumina factories, the content of alumina dry basis is 65 wt%) and 2g of sesbania powder, adding 85mL of aqueous solution dissolved with 2g of acetic acid into the materials, uniformly kneading, extruding and forming. The shaped wet mass was dried at 110 ℃ for 8 hours. And (3) placing the dried material in a tubular furnace, introducing nitrogen into the tubular furnace to fill the whole hearth with the nitrogen, roasting for 6 hours at 400 ℃, then discharging the nitrogen, introducing air, and roasting for 6 hours at 600 ℃ to obtain the silicon-containing alumina carrier S1.

4) 100 g of the above silicon-containing alumina support S1 was weighed into a beaker and immersed in 100mL of a molybdenum-nickel-phosphorus active metal impregnation solution (equivalent to containing MoO)₃10 g, nio1.2 g) for 5 hours, filtering off the excess solution, drying the impregnated material at 120 ℃ for 6 hours, and then roasting at 500 ℃ for 5 hours.

5) Placing the calcined catalyst obtained in the step 4) in a sealed tubular furnace, introducing mixed gas of ammonia gas and water vapor, wherein the partial pressure of the ammonia gas is 30%, controlling the pressure of the mixed gas in the tubular furnace to be 4MPa, and carrying out sealing heat treatment for 8 hours at 125 ℃. The sealed heat treated catalyst was dried at 120 ℃ for 5 hours to obtain silicon-containing hydrodemetallization catalyst C1, the properties of which are shown in Table 1.

Example 2

A silicon-containing hydrodemetallization catalyst was prepared in the same manner as in example 1, except that:

in the step 1), the particle size of the first carbon black powder is 325 meshes, the adding amount is 12.5 g, and 3.8mL of methyl orthosilicate ethanol solution (the using amount is 30% of the saturated water absorption amount of the first carbon black powder, wherein the using amount is equivalent to 2g of silicon dioxide) is used for spray-soaking the first carbon black powder.

In the step 2), the particle size of the second carbon black powder is 1100 meshes, the addition amount is 7.5 g, and 7.5mL of an ethanol solution of methyl orthosilicate (the amount is the saturated water absorption amount of the second carbon black powder, which is equivalent to 1 g of silicon dioxide) is used for spray-soaking the second carbon black powder.

In the step 3), the roasting temperature is 500 ℃ in a nitrogen atmosphere and 750 ℃ in an air atmosphere.

In the step 5), the pressure of the mixed gas is 3MPa, wherein the partial pressure of ammonia gas is 50%, the heat treatment temperature is 150 ℃, and the treatment time is 5 hours.

Thus, a silicon-containing hydrodemetallization catalyst C2 was obtained, the properties of which are shown in Table 1.

Example 3

in the step 1), the particle size of the first carbon black powder is 540 meshes, the adding amount is 10 g, and 4.5mL of methyl orthosilicate ethanol solution (the using amount is 45% of the saturated water absorption amount of the first carbon black powder, wherein the using amount is equivalent to 6 g of silicon dioxide) is used for spray-soaking the first carbon black powder.

In the step 2), the particle size of the second carbon black powder is 1800 meshes, the addition amount is 10 g, and 10mL of ethyl alcohol solution of methyl orthosilicate (the use amount is the saturated water absorption amount of the second carbon black powder, wherein the use amount is equivalent to 0.75 g of silicon dioxide) is used for spray-soaking the second carbon black powder.

In step 3), the calcination temperature in a nitrogen atmosphere was 600 ℃. The calcination temperature was 900 ℃ in an air atmosphere.

In the step 5), the pressure of the mixed gas is 5MPa, wherein the partial pressure of ammonia gas is 40%, the heat treatment temperature is 100 ℃, and the treatment time is 10 hours.

Thus, a silicon-containing hydrodemetallization catalyst C3 was obtained, the properties of which are shown in Table 1.

Example 4

A silicon-containing hydrodemetallization catalyst was prepared in the same manner as in example 1, except that: the dosage of the ethyl orthosilicate ethanol solution in the step 1) is the saturated water absorption capacity of the first carbon black powder (the contained ethyl orthosilicate amount is not changed). A silicon-containing hydrodemetallization catalyst C4 was obtained, the properties of which are shown in Table 1.

Example 5

A silicon-containing hydrodemetallization catalyst was prepared in the same manner as in example 1, except that: the dosage of the ethyl orthosilicate ethanol solution in the step 2) is 50 percent of the saturated water absorption capacity of the second carbon black powder (the contained amount of the ethyl orthosilicate is not changed). A silicon-containing hydrodemetallization catalyst C5 was obtained, the properties of which are shown in Table 1.

Example 6

A silicon-containing hydrodemetallization catalyst was prepared in the same manner as in example 1, except that: step 5) was not carried out, and a silicon-containing hydrodemetallization catalyst C6 was obtained, the properties of which are shown in Table 1.

Comparative example 1

A silicon-containing hydrodemetallization catalyst was prepared in the same manner as in example 1, except that: the first carbon black powder and the second carbon black powder are not dipped, namely the steps 1) and 2) are not carried out, and the same amount of the first carbon black powder, the second carbon black powder and the ethanol solution of the ethyl orthosilicate used in the steps 1) and 2) are directly carried out to the step 3). Finally, the silicon-containing hydrodemetallization catalyst DC1 is prepared, and the properties of the catalyst are shown in Table 1.

Comparative example 2

A silicon-containing hydrodemetallization catalyst was prepared in the same manner as in example 1, except that: the first carbon black powder is not impregnated, namely the step 1) is not carried out, and the same amount of the first carbon black powder and the ethanol solution of the ethyl orthosilicate in the step 1) and the impregnated second carbon black powder obtained in the step 2) are directly subjected to the step 3). Finally, the silicon-containing hydrodemetallization catalyst DC2 is prepared, and the properties of the catalyst are shown in Table 1.

Comparative example 3

A silicon-containing hydrodemetallization catalyst was prepared in the same manner as in example 1, except that: the second carbon black powder is not impregnated, namely the step 2) is not carried out, and the same amount of the second carbon black powder and the ethanol solution of the ethyl orthosilicate in the step 2) and the impregnated first carbon black powder obtained in the step 1) are directly subjected to the step 3). Finally, the silicon-containing hydrodemetallization catalyst DC3 is prepared, and the properties of the catalyst are shown in Table 1.

TABLE 1 Properties of the catalysts

*: pore distribution refers to the percentage of the total pore volume occupied by the pore volume of pores within the corresponding diameter range in the support.

Test example

The following examples illustrate the catalytic performance of the catalysts prepared by the process of the present invention versus the comparative catalysts.

The feedstock oils shown in Table 2 were used as raw materials and evaluated in a 200-ml hydrogenation reactorThe silicon-containing hydrodemetallization catalyst has the catalytic performance of C1-6 and DC1-3, the catalyst is in a strip shape with the length of 2-3 mm, the loading amount of the catalyst is 100ml, the reaction temperature is 375 ℃, the hydrogen partial pressure is 13MPa, and the liquid hourly space velocity is 1.0 hour^-1The volume ratio of hydrogen to oil was 1000, the content of each impurity in the produced oil was measured after 200 hours of reaction, the relative metal removal rate was calculated, and the evaluation results are shown in table 3.

TABLE 2 Properties of the feed oils

Item	Content (wt.)
		S，wt％	4.21
Ni，μg/g	21.5
		V，μg/g	83.2

TABLE 3 hydrogenation Properties of the catalysts

	C1	C2	C3	C4	C5	C6	DC1	DC2	DC3
										Metal removal rate,%	86.2	88.7	85.1	83.1	82.8	81.5	53.7	55.9	58.4

From the results of table 3, it can be seen that the hydrodemetallization catalyst prepared by the process of the present invention has higher hydrodemetallization activity than the comparative example.

The catalysts prepared in the above examples and comparative examples were evaluated for activity and the temperature rise at 5000h of operation is shown in Table 4.

TABLE 4 reaction temperature increase values

Catalyst and process for preparing same	The reaction temperature after 5000 hours of reaction was raised to a high value of DEG C
		C1	18
C2	17
		C3	18
C4	19
		C5	20
C6	21
		DC1	27
DC2	26
		DC3	25

From the results in table 4, it is seen that after 5000 hours of reaction, the hydrodemetallization catalyst provided by the present invention is adopted, and in order to maintain high demetallization rate, the required reaction temperature is increased by a much smaller extent than that of the comparative catalyst, which indicates that the hydrodemetallization catalyst provided by the present invention has higher activity stability.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims

1. A preparation method of a silicon-containing hydrodemetallization catalyst is characterized by comprising the following steps,

(4) carrying out sealing heat treatment and third drying treatment on the silicon-containing hydrodemetallization catalyst obtained in the step (3);

wherein the first silicon-containing solution and the second silicon-containing solution both contain silicate esters,

the particle size of the first physical pore-expanding agent is 100-540 meshes, the particle size of the second physical pore-expanding agent is 900-2000 meshes, and the weight ratio of the first physical pore-expanding agent to the second physical pore-expanding agent is 2-3: 1;

the dosage ratio of the first silicon-containing solution to the second silicon-containing solution is 2-12: 1;

the sealing heat treatment is carried out in the mixed atmosphere of ammonia and water vapor.

2. The production method according to claim 1, wherein the conditions of the sealing heat treatment include: the gas pressure is 3-5MPa, the partial pressure of ammonia gas is 30-50%, the rest is water vapor, the heat treatment temperature is 100-150 ℃, and the treatment time is 5-10 hours.

3. The method according to claim 1, wherein the conditions of the third drying process include: the temperature is 80-120 ℃ and the time is 6-10 hours.

4. The production method according to claim 1, wherein the first physical pore-enlarging agent and the second physical pore-enlarging agent are each selected from one or more of carbon black powder, charcoal, or wood chips.

5. The production method according to claim 4, wherein both the first physical pore-expanding agent and the second physical pore-expanding agent are carbon black powder.

6. The preparation method according to claim 1, wherein a weight ratio of the first physical pore-enlarging agent to the second physical pore-enlarging agent is 2.5-3: 1.

7. the production method according to claim 6, wherein the first physical pore-expanding agent is added in an amount of 10 to 15 wt% based on the dry basis of alumina.

8. The production method according to claim 6, wherein the second physical pore-expanding agent is added in an amount of 5 to 10 wt% based on the dry basis of alumina.

9. The production method according to claim 1, wherein the solvents of the first silicon-containing solution and the second silicon-containing solution are respectively selected from one or more of ethanol, methanol, and acetone.

10. The production method according to claim 9, wherein the silicate is a fatty alcohol orthosilicate and/or a fatty alcohol metasilicate.

11. The method according to claim 10, wherein the silicate is one or more of methyl orthosilicate, ethyl orthosilicate, propyl orthosilicate, and butyl orthosilicate.

12. The production method according to any one of claims 1 to 11, wherein the first silicon-containing solution and the second silicon-containing solution are used in a total amount of 2.5 to 7 wt% on a dry basis of alumina, in terms of silica.

13. The production method according to any one of claims 1 to 11, wherein the volume of the first silicon-containing solution is 30 to 50% of the saturated water absorption capacity of the first physical pore-enlarging agent.

14. The method of claim 13, wherein the volume of the second silicon-containing solution is the saturated water absorption capacity of the second physical pore-enlarging agent.

15. The method according to claim 1, wherein an extrusion aid and/or a peptizing agent is further added during the mixing in the step (2).

16. The production method according to claim 1, wherein the conditions of the first drying include: the temperature is 100 ℃ and 130 ℃, and the time is 1-10 hours.

17. The production method according to claim 16, wherein the first firing includes: the firing is performed in a nitrogen atmosphere and then in an air atmosphere.

18. The preparation method as claimed in claim 17, wherein the calcination temperature under the nitrogen atmosphere is 400-600 ℃, the calcination time is 4-6 hours, the calcination temperature under the air atmosphere is 600-900 ℃, and the calcination time is 4-8 hours.

19. The preparation method according to any one of claims 1 to 11, wherein the hydrogenation active component impregnation liquid contains metals of groups VIB and VIII.

20. The method of claim 19, wherein the group VIB metal content, calculated as the oxide, is from 7 to 15g/100mL and the group VIII metal content, calculated as the oxide, is from 0.8 to 3g/100 mL.

21. A silicon-containing hydrodemetallization catalyst prepared by the process of any of claims 1-20.

22. Use of the silicon-containing hydrodemetallization catalyst of claim 21 in hydrodemetallization reactions.