CN111100680A

CN111100680A - Catalyst grading method and residual oil hydrotreating method

Info

Publication number: CN111100680A
Application number: CN201811257597.2A
Authority: CN
Inventors: 耿新国; 蒋立敬; 刘铁斌; 翁延博; 李洪广; 金建辉
Original assignee: China Petroleum and Chemical Corp; Sinopec Dalian Research Institute of Petroleum and Petrochemicals
Current assignee: China Petroleum and Chemical Corp; Sinopec Dalian Research Institute of Petroleum and Petrochemicals
Priority date: 2018-10-26
Filing date: 2018-10-26
Publication date: 2020-05-05

Abstract

The invention provides a catalyst grading method and a residual oil hydrotreating method. The method comprises the steps of sequentially filling a hydrogenation protective agent bed layer, a hydrogenation demetalization catalyst bed layer, a hydrogenation desulfurization catalyst bed layer and a hydrogenation denitrification and/or carbon residue removal catalyst bed layer in a plurality of hydrogenation reactors connected in series, wherein a catalyst bed layer L1 filled with at least one hydrogenation treatment catalyst M is arranged behind the hydrogenation denitrification and/or carbon residue removal catalyst bed layer, the diameter of a carrier of the hydrogenation treatment catalyst M is 2.5-8 mm, the outer surface of the carrier is provided with a plurality of large pore channels which are not communicated with each other, the sectional area of each large pore channel is gradually reduced from outside to inside along the radial direction, the area of the bottom surface of each large pore channel is 0.05-5% of the surface area of a sphere, and the longest depth of each large pore channel is 30-99% of the radius. The method of the invention is suitable for treating residual oil with high content of iron and calcium impurities, not only can effectively remove and attach the iron and/or calcium impurities, has high overall activity of the catalyst, but also can prolong the running period of the device.

Description

Catalyst grading method and residual oil hydrotreating method

Technical Field

The invention belongs to the technical field of residual oil hydrogenation, and particularly relates to a heavy inferior residual oil hydrotreating method with high iron and calcium impurity content.

Background

As crude oil gets heavier and worse, more and more heavy oil and residual oil need to be processed. The processing treatment of heavy oil and residual oil not only needs to crack the heavy oil and residual oil into low boiling point products, such as naphtha, middle distillate oil, vacuum gas oil and the like, but also needs to improve the hydrogen-carbon ratio of the heavy oil and residual oil, and the processing treatment needs to be realized by a decarburization or hydrogenation method. Wherein the decarbonization process comprises coking, solvent deasphalting, heavy oil catalytic cracking and the like; the hydrogenation process comprises hydrocracking, hydrofining, hydrotreating and the like. The hydrogenation process can not only hydrogenate and convert residual oil and improve the yield of liquid products, but also remove heteroatoms in the residual oil, has good product quality and has obvious advantages. Therefore, each oil refining enterprise creates a residual oil hydrotreater in succession to process heavier and inferior residual oil so as to obtain better benefit.

The raw material cracking rate of heavy oil and residual oil hydrotreating technology is low, and the main purpose is to provide raw materials for downstream raw material lightening devices such as catalytic cracking or coking devices. The impurity content of sulfur, nitrogen, metal and the like in the inferior residual oil and the carbon residue value are obviously reduced through hydrotreating, so that the feed which can be accepted by a downstream raw material lightening device is obtained.

For a catalytic cracker, if the iron and/or calcium content of the feed is too high, the accessibility of heavy oil molecules to the catalyst sites is reduced, resulting in a reduced conversion of heavy oil. Moreover, too high a content of iron and/or calcium in the feed also causes formation of nodules on the catalyst surface, resulting in a decrease in bulk density, which in turn affects the catalyst circulation between the reactor and the regenerator, and in severe cases, the plant processing load. In addition, iron has a dehydrogenation effect, resulting in a high hydrogen/methane ratio in the dry gas. In conclusion, too high iron and/or calcium content in the feed will result in reduced heavy oil conversion, poor product selectivity, impact on plant processing load and thus on plant-wide economic efficiency. Therefore, it is imperative to control the iron and/or calcium content of the catalytic cracking feed.

In the fixed bed residual oil hydrogenation process, the feeding materials are heavy oil or residual oil raw materials containing metal impurities, the metal impurities can be deposited on the surface and in the pore channels of the catalyst in the process of removing the metal impurities, particularly iron and/or calcium are mainly deposited on the outer surface of the catalyst, so that the void ratio of a catalyst bed layer is rapidly reduced, the pressure drop of the bed layer is increased, and the operation period of the device is influenced.

CN1335368A discloses a residual oil treatment method. The method comprises the following steps: before hydrogenation reaction, heavy oil and residual oil are first treated through adsorption and filtering to eliminate suspended particles carried by the material and to eliminate ferrous sulfide and most coke-forming matter produced by iron naphthenate in the crude oil, so as to reduce scaling in residual oil hydrogenating reactor and prolong the running period of the apparatus. However, this method requires additional pretreatment equipment, and iron naphthenate is not reacted and still dissolved in the feedstock before the hydrotreating, and thus the iron removal effect is not good.

CN103289734A discloses a high-metal, high-sulfur and high-nitrogen inferior heavy oil hydrotreating process and catalyst grading combination, which comprises two series-connected upflow type de-ironing reactor, a fixed bed de-metallization reactor, a fixed bed desulfurization reactor and a fixed bed denitrification reactor, wherein the upflow type de-ironing reactor is filled with a hydrodeironing de-ironing de-metallization catalyst, and active metal components of the hydrodeironing de-metallization catalyst are distributed in a yolk shape from the center to the outer surface of catalyst particles, so as to prolong the operation period of the device. The method can adjust the distribution of the removed iron and calcium on the catalyst to a certain degree, but still cannot solve the problem that the iron and calcium impurities are easy to deposit on the outer surface of the catalyst, so that the pressure drop is increased too fast, and the running period of the device is influenced.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a catalyst grading method and application thereof in a residual oil hydrotreating method. The catalyst grading method is especially suitable for treating residual oil with high iron and calcium impurity content, and can eliminate and attach iron and/or calcium impurity effectively, raise the activity of the catalyst and prolong the operation period of the apparatus.

The inventor of the invention finds that iron and calcium in the residual oil can be divided into two major types, namely organic and inorganic types, wherein inorganic type iron and calcium is easy to remove, but organic type iron and calcium is not easy to remove, even ferrous sulfide and calcium sulfide are generated and are adhered to the surface of the catalyst, and the iron sulfide and calcium sulfide fragments and particles which fall off easily penetrate through the catalyst bed along with material flow, and the fallen ferrous sulfide and calcium sulfide fragments and particles can enter a downstream catalyst bed, particularly two catalyst interface positions with obvious particle size transition and catalyst pore size transition exist, so that the void ratio of the downstream catalyst bed is reduced, the bed pressure drop is increased, even the local material flow of the bed is uneven, the radial temperature difference is generated, and the operation of downstream devices (such as catalytic cracking devices) is influenced. To this end, the inventors have invented a catalyst M and carried out reasonable grading packing to solve this problem.

The first aspect of the invention provides a catalyst grading method, which is characterized in that a hydrogenation protective agent bed layer, a hydrogenation demetallization catalyst bed layer and a hydrogenation desulfurization catalyst bed layer are sequentially filled in a plurality of hydrogenation reactors connected in series according to the material flow direction, and the rear part of the hydrogenation denitrification and/or carbon residue removal catalyst bed layer is connected with a hydrogenation denitrification and/or carbon residue removal catalyst bed layer, wherein a catalyst bed layer L1 filled with at least one hydrogenation treatment catalyst M is arranged behind the hydrogenation denitrification and/or carbon residue removal catalyst bed layer, the hydrogenation treatment catalyst M comprises a carrier and hydrogenation active metal components, the carrier is a sphere, the diameter of the carrier is 2.5-8.0 mm, the outer surface of the carrier is provided with a plurality of large pores which are not communicated, the sectional area of the large pores is gradually reduced from outside to inside along the radial direction, the bottom surface area of each large pore is 0.05-5% of the sphere, the total bottom area of the large pores is 5, the longest depth of the large pore channel is 30-99% of the radius of the spherical carrier, and preferably 55-96% of the length of the pore channel along the radius direction of the sphere.

In the catalyst grading method, the filling volume of the catalyst in the catalyst bed layer L1 accounts for 2-15%, preferably 5-10% of the total filling volume of the catalyst in all hydrogenation reactors.

In the hydrotreating catalyst M, the cross section of the macropore in the carrier is a spherical surface formed by taking the spherical center of the carrier as the spherical center and different radii, and the surface corresponding to the macropore on the spherical surface is the cross section.

Further, the macropores of the surface of the carrier extend from the outer surface to the direction of the center of the sphere.

Further, the bottom surface of the large pore channel in the carrier is at least one of round, oval, polygonal and irregular on the outer surface of the sphere.

Furthermore, the large pore channels of the carrier are conical pore channels or pyramid pore channels, and preferably, the angle of the vertex angle of the conical pore channels or the pyramid pore channels is 5-50 degrees.

Wherein the calculation formula of the sphere surface area is S = π D, D being the diameter of the sphere.

The sectional area of the large pore channels is gradually reduced from outside to inside along the radial direction, namely the sectional area of each large pore channel is gradually reduced along the whole interval range from outside to inside along the radial direction, but is allowed to be kept constant in one or more intervals. The interval refers to the distance between any two sections in the whole interval of the large pore passage, wherein the interval length of any interval does not exceed 1/4 of the longest depth of the large pore passage.

Further, the cross-sectional area of the large pore passage of the carrier is gradually reduced from the outside to the inside in the radial direction, and the minimum cross-sectional area accounts for 10% or less, preferably 5% or less, and more preferably 2% or less of the area of the bottom surface of the large pore passage.

Furthermore, the sectional area of the large pore channel of the carrier is gradually reduced from outside to inside along the radial direction, and the sectional area from the bottom to the position with the longest depth of 1/2 accounts for 20-70% of the area of the bottom of the large pore, preferably 25-65%.

Further, the sectional area of the large pore passage is gradually reduced from outside to inside along the radial direction, and the sectional area from the bottom surface to the position with the longest depth 1/2 accounts for 30% -80%, preferably 45% -75% of the sectional area from the bottom surface to the position with the longest depth 1/4.

Further, the sectional area of the large pore passage is gradually reduced from outside to inside along the radial direction, and the sectional area from the bottom surface to the position with the longest depth 3/4 accounts for 40% -80%, preferably 55% -75% of the sectional area from the bottom surface to the position with the longest depth 1/2.

Further, the width of the minimum cross section of the large pore channel is not more than 30 μm.

The macroporous channels are distributed on the surface of the carrier, wherein the minimum wall thickness between any two adjacent macroporous channels accounts for 1/8-1/5 of the diameter of the sphere. Wherein, the macropores on the surface of the carrier are preferably the same, i.e. the shape and size are substantially the same, and can be made into the same macropores by the same guide mold, and further preferably, the macropores of the carrier are uniformly distributed on the surface of the sphere.

In the hydrotreating catalyst M, the carrier is spherical, and is provided with conical large channels with vertexes pointing to a sphere center and bottoms on the surface of the sphere, the diameter of the spherical carrier is 2.5-8.0 mm, wherein the area of the bottom of each conical large channel is 0.05-4.5% of the surface area of the sphere, the area of the total bottom of the conical large channels is 5-50% of the surface area of the sphere, the height of each conical large channel is 50-99% of the radius of the spherical carrier, preferably 55-96%, the angle of the vertex angle of each conical large channel is 5-50 degrees, and the conical channels of the carrier are uniformly distributed on the surface of the sphere.

Furthermore, 4-40 conical large channels, preferably 8-40 conical large channels are arranged in the carrier of the hydrotreating catalyst M.

The hydrotreating catalyst M of the invention is composed of Al₂O₃-SiO₂Is a carrier, wherein SiO is based on the weight of the carrier₂Weight (D)The content is 20-50%, preferably 30-40%.

The support of the hydrotreating catalyst M of the present invention preferably further contains a first metal component oxide, and the first metal component oxide is NiO. The first metal component oxide NiO and Al₂O₃Is 0.03: 1-0.13: 1, preferably 0.05: 1-0.11: 1.

the properties of the support of the hydrotreating catalyst M of the invention are as follows: the specific surface area is 100-200 m²The pore volume is more than 0.70mL/g, preferably 0.75-1.15 mL/g, the pore volume occupied by the pore diameter of 20-100 nm is 35-60% of the total pore volume, and the average pore diameter is more than 15nm, preferably 17-30 nm.

In the hydrotreating catalyst M of the present invention, the active metal component includes a second metal component, i.e., a group vib metal, and a third metal element, i.e., a group viii metal element, where the group vib metal is preferably Mo, and the group viii metal is preferably Ni and/or Co.

In the hydrotreating catalyst M, the content of the second metal component in terms of oxide is 1.0-30.0%, preferably 1.5-20%, the total content of the first metal component and the third metal component in terms of oxide is 1.0-35.0%, preferably 2.0-25.0%, the content of silicon oxide is 25.0-35.0%, and the content of aluminum oxide is 55.0-65.0%, based on the weight of the catalyst.

The second aspect of the invention provides an application of the catalyst grading method in a residual oil hydrotreating method, wherein under the hydrotreating reaction condition, a residual oil raw material and hydrogen sequentially pass through a plurality of serially connected hydrogenation reactors, and contact with a catalyst filled in the hydrogenation reactor according to the grading method to carry out a hydrogenation reaction, so that a hydrotreated product is obtained.

In the residue oil hydrotreating method of the present invention, the operating conditions of each reactor are, independently: the reaction pressure is 5-25 MPa, the reaction temperature is 300-430 ℃, and the liquid hourly space velocity is 0.05-5.0 h^-1The volume ratio of hydrogen to oil is 150: 1-1000: 1.

Compared with the prior art, the invention has the advantages that:

1. the method is based on the conventional residual oil hydrogenation catalyst gradation, a catalyst bed layer L1 filled with a hydrogenation catalyst M is arranged behind a hydrogenation denitrification and/or residual carbon removal catalyst bed layer, because the hydrogenation catalyst M has proper granularity, pore channel structure and unique channel structure, iron and calcium impurities in residual oil can be removed, and the iron and calcium impurities are effectively deposited and attached in a large pore channel on the outer surface of the catalyst, thereby reducing the influence of the iron and calcium impurities on downstream devices, simultaneously having higher demetalization activity, further deeply removing metal impurities Ni and V, further having certain desulfurization and residual carbon removal activities, more importantly, the conventional residual oil hydrogenation process is a heat release process, the tail end of the hydrogenation denitrification and/or residual carbon removal catalyst bed layer is a position with the highest reaction temperature, after the mixed residual oil is subjected to hydrogenation treatment of a series of catalyst bed layers in the front part, the light aromatic hydrocarbon, the middle aromatic hydrocarbon and part of colloid are saturated and converted in a large amount, the aromaticity of the asphaltene is higher after the hydrogenation treatment of the high-activity catalyst bed layer, the asphaltene with high aromaticity becomes more unstable in the colloid environment with greatly reduced aromatic hydrocarbon and colloid, the catalyst is easier to be condensed and condensed to form carbon deposition in a high-temperature area, the asphaltene which is easy to deposit is deposited in a conical large pore channel of the catalyst M to form the carbon deposition by arranging the hydrotreating catalyst bed layer L1 at the position, the part of the carbon deposition is prevented from being deposited in a heat exchanger, a separator and a fractionating system at the lower part and the downstream of the denitrification/carbon residue removal catalyst bed layer, the shutdown maintenance caused by the blockage of subsequent equipment and pipelines is avoided, the operation period of the device is shortened, therefore, through the arrangement of the catalyst bed layer L1, the good overall activity and stability can be achieved without increasing the total filling volume of the catalyst, which is beneficial to prolonging the running period of the hydrogenation device.

2. The surface of the hydrotreating catalyst M adopted by the invention is provided with a certain number of large channels with certain sizes, the large channels are not communicated and do not penetrate, the sectional area of the large channels is gradually reduced from outside to inside along the radial direction, and the shape of the large channels is preferably conical (conical or pyramidal). The large pore channels on the catalyst particles can greatly reduce the diffusion distance and resistance of residual oil molecules to the interior of the catalyst particles. The non-communicated and non-penetrated pore canal prevents the residual oil material flow from directly flowing out of the pore canal, thereby improving the retention time of the residual oil material flow in the pore canal and increasing the deposition probability of particulate matters and dirt. The inventor creatively discovers through a large number of experiments that the pore channel of the catalyst carrier has a conical structure, the front end of the conical pore channel is an acute angle, and the reacted particles and scales are easy to bridge within a distance of 20-30 mu m of the pore channel to form a micron-sized grid and gradually expand from inside to outside in the large pore channel, so that the deposition and adhesion efficiency of the scales such as iron is greatly improved. The general prepared through-channels are more than 0.1mm, bridging space with the distance of 20-30 mu m is not easy to provide, and simultaneously, due to the through-channels, material flow scouring exists, the difficulty of deposit of the dirt is increased, and the deposit and adhesion efficiency of the dirt is reduced.

3. In the method, a small amount of nickel salt is preferably added into the catalyst carrier, so that a proper amount of nickel-aluminum spinel structure is generated in the roasting process, the strength and the water resistance of the catalyst are further improved, and the catalytic performance is not influenced.

4. The catalyst grading filling method can be used for the hydrotreatment of the residual oil, and is particularly suitable for the hydrotreatment of the iron-containing residual oil, the content of organic iron and inorganic iron in the residual oil can be more than 10 mu g/g or more than 20 mu g/g in terms of iron, and the content of calcium can be more than 10 mu g/g or more than 20 mu g/g. The catalyst grading filling method of the invention not only can effectively remove and attach iron and/or calcium impurities, has high overall activity of the catalyst, but also can prolong the running period of the device.

Drawings

FIG. 1 is a schematic sectional view of a process for preparing a support of a residual oil hydrotreating catalyst M of the present invention;

FIG. 2 is a schematic view of a hemispherical cavity mold for forming a mold shell;

FIG. 3 is a schematic sectional view of a support of the catalyst M prepared;

FIG. 4 is a schematic perspective view of a support for the catalyst M prepared;

the reference numerals are explained below:

1. a mold housing; 2. a pasty material; 3. a guide die capable of forming a conical large pore channel; 4. a cavity; 5. conical shaped prickles; 6. a conical bore.

Detailed Description

The technical solution of the present invention is further described in detail with reference to the following examples, which are not intended to limit the scope of the present invention. In the present invention, wt% is a mass fraction.

In the invention, the specific surface area, the pore volume, the pore diameter and the pore distribution are measured by adopting a low-temperature liquid nitrogen adsorption method.

The hydrotreating catalyst M of the present invention can be prepared by a process comprising:

(1) adding an acidic peptizing agent into a silicon source for acidification treatment;

(2) adding pseudo-boehmite and a curing agent into the step (1) to prepare a paste material;

(3) adding the paste material obtained in the step (2) into a mould, and heating the mould containing the paste material for a certain time to solidify and form the paste material;

(4) removing the material in the step (3) from the mold, washing, drying and roasting to obtain a catalyst carrier;

(5) and (4) impregnating the carrier obtained in the step (4) with active metal components of the supported catalyst, and drying and roasting to obtain the hydrotreating catalyst M.

In the preparation method of the hydrotreating catalyst M of the present invention, the first metal oxide is preferably introduced into the support, and the first metal source (nickel source) may be introduced in step (1) and/or step (2), and the preferred introduction method is as follows: adding a nickel source into the material obtained in the step (1), and dissolving the nickel source into the material. The nickel source can adopt soluble nickel salt, wherein the soluble nickel salt can be one or more of nickel nitrate, nickel sulfate and nickel chloride, and nickel nitrate is preferred.

In the preparation method of the hydrotreating catalyst M, the silicon source in the step (1) is one or more of water glass and silica sol, wherein the mass content of silicon in terms of silicon oxide is 20-40%, preferably 25-35%; the acid peptizing agent is one or more of nitric acid, formic acid, acetic acid and citric acid, preferably nitric acid, and the mass concentration of the acid peptizing agent is 55-75%, preferably 60-65%; the adding amount of the acidic peptizing agent is that the molar ratio of hydrogen ions to silicon dioxide is 1: 1.0-1: 1.5; the pH value of the silicon source after acidification treatment is 1.0-4.0, preferably 1.5-2.5.

In the preparation method of the hydrotreating catalyst M, the dry weight of the pseudo-boehmite in the step (2) is more than 70 percent, and the pseudo-boehmite is converted into gamma-Al by high-temperature roasting₂O₃The latter properties are as follows: the pore volume is more than 0.95mL/g, the preferable pore volume is 0.95-1.2 mL/g, and the specific surface area is 270m²More than g, preferably the specific surface area is 270-330 m²(ii) in terms of/g. The curing agent is one or more of urea and organic ammonium salt. The organic ammonium salt is hexamethinetetrammonium. The addition amount of the curing agent is 1: 1.5-1: 2.0 in terms of the molar ratio of nitrogen atoms to silicon dioxide; the solid content of the prepared paste material is 25-45% by weight of silicon dioxide and aluminum oxide, preferably 28-40%, and the paste material is a plastic body with certain fluidity.

In the preparation method of the hydrotreating catalyst M of the present invention, the mold in the step (3) includes a shell with a spherical cavity and a guide mold capable of matching with the shape of the pore passage required by the present invention, the shell is made of a rigid material, and the external shape may be any shape, preferably a symmetrical geometric shape such as a sphere. The invention takes the mould with the spherical external shape and the membrane guiding structure capable of forming the conical pore as an example for explanation, and the spherical shell can be composed of two identical hemispheroids or four quarter spheres. The diameter of the spherical cavity can be adjusted according to the size of catalyst particles, so that the diameter of the final spherical carrier is 2.5-10.0 mm. The material of the guide mould is selected from substances which can be removed by heating or burning, such as graphite, wood, paper, paraffin or petroleum resin. The structure of the guide film is matched with a three-dimensional conical pore channel in the carrier, conical barbs are arranged towards the center of the sphere, the bottom surface of the guide film is connected with the surface of a quarter sphere, the thickness d of the guide film except the conical barbs is 0-2 mm, and the conical barbs in the guide film are centrosymmetric. Thereby forming a guided mode capable of producing a conical bore.

The structure of the guide die is matched with the pore channel in the carrier, and the conical pore channel is generated after the guide die is removed.

In the preparation method of the hydrotreating catalyst M, in the step (3), spherical shells of all parts are fixed with each other to form two complete hemispheroid cavities, four guide molds are spliced into two hemispheroids and are respectively placed in the two complete hemispheroid cavities, at the moment, a paste material is injected or pressed into the two hemispheroid cavities, and the two hemispheroids are combined together to form a complete sphere and are fixed after the whole cavities are filled.

In the preparation method of the hydrotreating catalyst M, in the step (3), the heating temperature of the die for containing the paste material is 70-200 ℃, preferably 100-150 ℃, and the constant temperature time is 30-240 minutes, preferably 50-120 minutes, so that the material is cured.

In the preparation method of the hydrotreating catalyst M, the mold is removed in the step (4), namely the lower shell is taken, and the pasty material in the mold releases alkaline gas after being heated, so that the pasty material is solidified and contracted to automatically remove the spherical shell. In the step (4), the spherical material after the spherical shell is removed is washed to be neutral by deionized water, and the quarter sphere is used as a guide die, so that the guide die and the sphere can be automatically separated due to the washing, disturbance and soaking of the deionized water in the washing process, and the sphere is provided with a needed large pore channel. The drying temperature is 100-150 ℃, and the drying time is 4-10 hours. The roasting temperature is 500-900 ℃, preferably 550-800 ℃, and the roasting time is 2-8 hours.

In the preparation method of the hydrotreating catalyst M of the present invention, the drying and calcining conditions after the carrier is impregnated with the catalyst active metal component in the step (5) are as follows: drying at 100-150 ℃ for 4-10 hours, and roasting at 400-600 ℃ for 2-6 hours.

In the invention, a hydrogenation protective agent bed layer is generally filled with a hydrogenation protective agent, a hydrogenation demetallization catalyst bed layer is generally filled with a hydrogenation demetallization catalyst, a hydrogenation desulfurization catalyst bed layer is generally filled with a hydrogenation desulfurization catalyst, and a hydrogenation denitrification and/or carbon residue removal catalyst bed layer is generally filled with a hydrogenation denitrification and/or carbon residue removal catalyst, namely a catalyst with hydrogenation denitrification and/or carbon residue removal functions. The catalyst can be catalyst used in routine field, and the loading can be loading routine in field. Based on the total filling volume of the catalysts in all reactors, the filling amount of the catalyst in the hydrogenation protection catalyst bed layer can be 5-30%, the filling amount of the catalyst in the hydrogenation demetallization catalyst bed layer can be 5-60%, the filling amount of the catalyst in the hydrogenation desulfurization catalyst bed layer can be 15-50%, and the filling amount of the catalyst in the hydrogenation denitrification and/or carbon residue removal catalyst bed layer can be 5-50%.

In the present invention, the hydrogenation protection catalyst, the hydrodemetallization catalyst, the hydrodesulfurization catalyst, and the hydrodenitrogenation and/or carbon residue removal catalyst may be a catalyst having such functions, which is conventional in the art. Generally, the catalyst is prepared by taking a heat-resistant porous inorganic oxide such as alumina as a carrier, taking a VIB group metal and/or a VIII group metal as an active metal component, taking the VIB group metal as at least one of W and Mo, taking the VIII group metal as at least one of Co and Ni, and further comprising an auxiliary agent component selected from at least one of P, Si, F and B. When in use, various catalysts can be purchased separately and then combined, or a full series of residual oil hydrotreating catalysts comprising the various catalysts can be purchased directly and commercially, such as FZC series residual oil hydrotreating catalysts developed by China petrochemical industry research institute, a hydrogenation protective agent FZC-100B, FZC-12B, FZC-13B, a hydrogenation demetallization catalyst FZC-28A, FZC-204A, a hydrogenation desulfurization catalyst FZC-33B, FZC-34A and a hydrogenation denitrification and carbon residue removal catalyst FZC-41B.

The catalyst grading filling method can be used for the hydrotreatment of residual oil, and is particularly suitable for the hydrotreatment of residual oil containing iron and/or calcium. Preferably, the content of organic iron and inorganic iron in the residual oil raw material is more than 10 mu g/g, more preferably more than 20 mu g/g, and the content of calcium is more than 10 mu g/g, more preferably more than 20 mu g/g in terms of iron. The residual oil is at least one of atmospheric residual oil and vacuum residual oil, and can also be heavy oil containing residual oil components, such as heavy oil and the like. The residual feedstock may contain various conventional impurities such as sulfur, nitrogen content, asphaltenes, metallic impurities, carbon residue, and the like. The properties of the resid feedstock can be: the sulfur content is not more than 4wt%, the nitrogen content is not more than 0.7wt%, the metal content (Ni + V) is not more than 140 mug/g, the carbon residue value is not more than 17wt%, and the asphaltene content is not more than 5 wt%. The residual oil raw material can be blended with straight-run wax oil and/or vacuum wax oil, or can be blended with secondary processing wax oil and/or catalytic refining oil and the like.

The method of the invention can adopt hydrogenation reactors with different structures, and each hydrogenation reactor can adopt upflow feeding or downflow feeding.

In the invention, the number of the plurality of hydrogenation reactors is preferably 2-5; the number of the catalyst beds in each hydrogenation reactor is 1-7, preferably 2-5. The number of hydrogenation reactors and the number of hydrogenation catalyst beds in each hydrogenation reactor can be properly adjusted according to the needs.

In the present invention, if the hydrodemetallization catalyst bed and the hydrodesulfurization catalyst bed are placed in different hydrogenation reactors, respectively, the hydrotreating catalyst bed L1 is preferably placed in the reactor in which the hydrodemetallization catalyst bed is located.

The hydrotreating catalyst M of the present invention will be described in detail below with reference to the drawings.

The present invention is described by taking the example that the external shape is spherical and the guide film is capable of forming a conical pore channel, as shown in fig. 1-4, when the present invention is used for preparing a residual oil hydrotreating catalyst carrier, the mold comprises a shell 1 with a spherical cavity (see fig. 1) and a guide film 3 capable of forming a conical pore channel (see fig. 1). The invention is illustrated by the outer shape being spherical, the spherical shell may be composed of two identical hemispheres. The spherical cavity has a diameter D (see fig. 1). The guide mold is made of heat or combustion removable material, such as graphite, wood, paper, paraffin or petroleum resin. The structure of the guide die is matched with a three-dimensional conical pore channel in the carrier, a conical burr 5 is arranged towards the center of the sphere, the bottom surface of the guide film is connected with the surface of a quarter sphere, the thickness of the part of the guide film, except the conical burr 5, is d, and the conical burr in the guide film is in central symmetry. See in particular fig. 1 and 3. The conical bore 6 created after the guide die is removed.

In the method, firstly, spherical shells of all parts are fixed with each other to form two complete hemispheroid cavities 4 (see figure 2), a guide die capable of forming a three-dimensional conical pore passage is placed into one hemispheroid cavity 4, the pasty material 2 is pressed into the two hemispheroid cavities 4, and the two hemispheroids are combined to form a complete sphere and fixed after the whole cavity is filled. The guide film forms conical cells 6 as shown in fig. 3. The catalyst carrier prepared by the invention is shown in a schematic perspective view in figure 4.

Example 1

Weighing 400g of water glass with the silicon oxide content of 30wt%, adding the water glass into a beaker, starting a stirring device, slowly adding 150g of nitric acid solution with the mass concentration of 62% into the beaker, adding nickel nitrate, stirring and dissolving the mixture until the pH value of the water glass solution in the beaker is 2.0, and adding 385.3g of pseudo-boehmite (with the properties of the pore volume of 1.05mL/g and the specific surface area of 306 m) into the solution²The dry basis is 70 wt%), the molar ratio of nickel oxide to aluminum oxide in the carrier is controlled to be 0.06:1, 35g of curing agent urea is added after uniform stirring, deionized water is added after the urea is completely dissolved, so that the material in the beaker is in a paste state with certain fluidity, and the solid content is 33% in terms of silicon dioxide and aluminum oxide.

The pasty material is pressed into two identical hemispheres with spherical cavities. Wherein, a hemisphere is put into a guide die, and the guide die is made of wood. The guide film of the spherical carrier is matched with the carrier, a conical pore channel structure can be formed, the guide film is divided into a quarter sphere, and the guide film is provided with 6 conical prickles towards the center of the sphere. The vertex of the conical prickle points to the center of the sphere, and the bottom surface of the conical prickle is connected with the surface of a quarter of the sphere. The conical pore channels of the carrier are uniformly distributed on the surface of the sphere.

The pasty material is pressed into the two hemispheroidal cavities, and the two hemispheroids are combined together to form a complete sphere and fixed after the whole cavity is filled with the pasty material.

Heating a mould containing the paste material to 120 ℃, keeping the temperature for 60 minutes, releasing ammonia gas after the paste material in the mould is heated to enable the paste material to be solidified and contracted, then automatically demoulding to form spherical gel, washing the spherical gel to be neutral by deionized water, drying for 5 hours at 120 ℃, and roasting for 3 hours at 750 ℃ to obtain the spherical catalyst carrier A. Wherein, the diameter of the obtained catalyst carrier A is 3mm, the number of the conical pore canals is 24, the height of the conical pore canals is 1.2mm, the angle of the vertex angle of the conical pore canal is 20 degrees, the area of the bottom surface of the conical pore canal is 0.754 percent of the surface area of the sphere, and the total area of the conical bottom surface is 18 percent of the surface area of the sphere.

The carrier A was impregnated with Mo-Ni-P solution, dried at 120 ℃ for 6 hours, and calcined at 500 ℃ for 3 hours to obtain the catalyst M1 of the present invention, the catalyst properties are shown in Table 1.

Example 2

The preparation was carried out as in example 1, except that the amount of nickel nitrate was increased to control the molar ratio of nickel oxide to alumina in the carrier to be 0.10:1, and the properties of the prepared catalyst carrier B and the prepared catalyst M2 were as shown in Table 1.

The diameter of the obtained catalyst carrier B is 8mm, the number of the conical pore channels is 40, the height of the conical pore channels is 3.5mm, the angle of the vertex angle of the conical pore channel is 15 degrees, the area of the bottom surface of the conical pore channel is 0.43 percent of the surface area of the sphere, and the total area of the conical bottom surfaces is 17 percent of the surface area of the sphere.

Example 3

The procedure is as in example 1 except that the curing agent urea was changed to 46.6g hexamethylenetetramine and catalyst support C and catalyst M3 were prepared having the properties shown in Table 1.

Wherein, the diameter of the obtained catalyst carrier C is 6mm, the number of the conical pore canals is 40, the height of the conical pore canals is 2.5mm, the angle of the apex angle of the conical pore canal is 25 degrees, the area of the bottom surface of the conical pore canal is 1.17 percent of the surface area of the sphere, and the total area of the conical bottom surfaces is 46.85 percent of the surface area of the sphere.

Example 4

The procedure is as in example 1 except that no nickel nitrate is added and catalyst support D and catalyst M4 are prepared having the properties shown in Table 1.

Example 5

The procedure was as in example 1 except that the amount of urea as a curing agent was changed to 40g, and the properties of the catalyst carrier E and the catalyst M5 were as shown in Table 1.

Wherein, the diameter of the obtained catalyst carrier E is 2.8mm, the number of the conical pore canals is 40, the height of the conical pore canals is 0.8mm, the angle of the vertex angle of the conical pore canal is 10 degrees, the area of the bottom surface of the conical pore canal is 0.19 percent of the surface area of the sphere, and the total area of the conical bottom surfaces is 7.6 percent of the surface area of the sphere.

Example 6

Weighing 800g of water glass with the silicon oxide content of 30wt%, adding the water glass into a beaker, starting a stirring device, slowly adding 299g of nitric acid solution with the mass concentration of 62% into the beaker, adding nickel nitrate, stirring and dissolving the water glass solution, then keeping the pH value of the water glass solution in the beaker to be 2.0, and then adding 575g of pseudo-boehmite (the property is as follows: the pore volume is 1.05mL/g, the specific surface area is 306 m)²The dry basis is 70 wt%), the molar ratio of nickel oxide to aluminum oxide in the carrier is controlled to be 0.06:1, 75g of curing agent urea is added after uniform stirring, deionized water is added after the urea is completely dissolved, so that the material in the beaker is in a paste shape with certain fluidity, and the solid content is 35% in terms of silicon dioxide and aluminum oxide.

The guide film of the spherical carrier is matched with the carrier, a conical pore channel structure can be formed, the guide film is divided into a quarter sphere and is provided with 2 conical prickles towards the center of the sphere. The vertex of the conical prickle points to the center of the sphere, and the bottom surface of the conical prickle is connected with the surface of a quarter of the sphere. The conical pore channels of the carrier are uniformly distributed on the surface of the sphere.

Heating a mould containing the paste material to 120 ℃, keeping the temperature for 60 minutes, releasing ammonia gas after the paste material in the mould is heated to enable the paste material to be solidified and contracted, then automatically demoulding to form spherical gel, washing the spherical gel to be neutral by deionized water, drying for 5 hours at 120 ℃, and roasting for 3 hours at 800 ℃ to obtain the spherical catalyst carrier F. The diameter of the obtained catalyst carrier F is 5mm, the number of the conical pore channels is 8, the height of the conical pore channels is 1.8mm, the angle of the vertex angle of the conical pore channel is 45 degrees, the area of the bottom surface of the conical pore channel is 3.66 percent of the surface area of the sphere, and the total area of the conical bottom surfaces is 29.29 percent of the surface area of the sphere.

The carrier F was impregnated with Mo-Ni-P solution, dried at 120 ℃ for 6 hours, and calcined at 550 ℃ for 3 hours to obtain the catalyst M6 of the present invention, the catalyst properties are shown in Table 1.

Comparative example 1

Weighing 400g of water glass with the silicon oxide content of 30wt%, adding the water glass into a beaker, starting a stirring device, slowly adding 150g of nitric acid solution with the mass concentration of 62% into the beaker, then adding 42.9g of nickel nitrate, stirring and dissolving the mixture until the pH value of the water glass solution in the beaker is 2.0, and then adding 385.3g of pseudo-boehmite (with the properties as follows: the pore volume is 1.05mL/g, and the specific surface area is 306 m) into the solution²70wt% of dry basis), adding 35g of curing agent urea after uniformly stirring, adding deionized water after the urea is completely dissolved, and enabling the materials in the beaker to be in a paste shape with certain fluidity and the solid content of the materials calculated by silicon dioxide and aluminum oxide to be 33%.

The paste material was pressed into two identical hemispherical hollow rigid molds, the diameter of the spherical cavity being the same as in example 1 without a conductive film. After the whole cavity is filled, the two hemispheres are combined together to form a complete sphere and fixed.

Heating a mould containing the paste material to 120 ℃, keeping the temperature for 60 minutes, releasing ammonia gas after the paste material in the mould is heated to enable the paste material to be solidified and contracted, then automatically demoulding to form spherical gel, washing the spherical gel to be neutral by deionized water, drying for 5 hours at 120 ℃, and roasting for 3 hours at 750 ℃ to obtain the spherical catalyst carrier G of the comparative example, wherein the diameter of the obtained catalyst carrier G is 3 mm.

The carrier G was impregnated with a Mo-Ni-P solution, dried at 120 ℃ for 6 hours, and calcined at 500 ℃ for 3 hours to obtain the catalyst G of this comparative example_CThe catalyst properties are shown in Table 1.

Comparative example 2

Weighing 400g of water glass with the silicon oxide content of 30wt%, adding the water glass into a beaker, starting a stirring device, slowly adding 150g of nitric acid solution with the mass concentration of 62% into the beaker, then adding 42.9g of nickel nitrate, stirring and dissolving the mixture, and then adding water into the beakerThe pH of the glass solution was 2.0, and 385.3g of pseudo-boehmite (property: pore volume 1.05mL/g, specific surface area 306 m) was added to the above solution²70wt% of dry basis), adding 35g of curing agent urea after uniformly stirring, adding deionized water after the urea is completely dissolved, and enabling the materials in the beaker to be in a paste shape with certain fluidity and the solid content of the materials calculated by silicon dioxide and aluminum oxide to be 33%.

And pressing the pasty material into two rigid body molds with the same hemispherical hollow structure, and adjusting the diameter of the spherical cavity to enable the diameter of the final catalyst carrier to be 8mm without a guide film. After the whole cavity is filled, the two hemispheres are combined together to form a complete sphere and fixed.

Heating a mould containing the paste material to 120 ℃, keeping the temperature for 60 minutes, releasing ammonia gas after the paste material in the mould is heated to enable the paste material to be solidified and contracted, then automatically demoulding to form spherical gel, washing the spherical gel to be neutral by deionized water, drying for 5 hours at 120 ℃, and roasting for 3 hours at 750 ℃ to obtain the spherical catalyst carrier H of the comparative example, wherein the diameter of the obtained catalyst carrier H is 8 mm.

The carrier H was impregnated with Mo-Ni-P solution, dried at 120 ℃ for 6 hours, and calcined at 500 ℃ for 3 hours to obtain the catalyst H of this comparative example_CThe catalyst properties are shown in Table 1.

TABLE 1 Properties of catalyst supports and catalysts prepared in inventive and comparative examples

Catalyst carrier weaveNumber (C)	A	B	C	D	E	F	G	H
									Pore volume, mL/g	0.784	0.775	0.774	0.782	0.781	0.783	0.776	0.774
Specific surface area, m²/g	142	144	145	141	142	143	145	141
									Average pore diameter, nm	22.5	22.6	22.4	22.5	22.6	22.5	22.1	22.5
Hole distribution,%
									<8.0 nm	0.8	0.9	0.7	0.8	0.8	0.9	1.1	1.2
8-20 nm	62.4	62.1	62.3	62.5	62.2	62.1	63.2	63.4
									20-100 nm	36.8	37	37	36.7	37	37	35.7	35.4
Catalyst numbering	M1	M2	M3	M4	M5	M6	G_C	H_C
									Metal content, wt.%
MoO₃	15.7	15.6	15.7	15.7	15.5	15.6	15.7	15.6
									NiO	4.5	5.1	4.5	2.3	4.5	4.6	4.5	4.4
Lateral pressure strength, N/grain	42	44	35	39	49	40	87	93

Examples 7 to 12

In this embodiment, four downflow hydrogenation reactors are used, the first reactor (R1) is provided with a hydrogenation protecting agent bed layer in which a hydrogenation protecting agent is filled, the second reactor (R2) is provided with a hydrogenation demetallization catalyst bed layer in which a hydrogenation demetallization catalyst is filled, the third reactor (R3) is provided with a hydrodesulfurization catalyst bed layer in which a hydrodesulfurization catalyst is filled, the fourth reactor (R4) is provided with a hydrodenitrogenation/decarbonization catalyst bed layer and a catalyst bed layer L1 of a hydrotreating catalyst M, and the filling volume ratio of the two bed layers is 4: 1, wherein a hydrodenitrogenation/carbon residue removal catalyst and a hydrotreating catalyst M are respectively filled, and the volume ratio of the catalyst filled with R1, R2, R3 and R4 is 20:25:25: 30; wherein the catalyst beds L1 in examples 7-12 were loaded with hydrotreating catalysts M1-M6 prepared in examples 1-6, respectively, and the specific catalyst types and loading of each reactor are shown in Table 3. The properties of the residue feedstock treated in this example are shown in Table 2, the properties of the partial catalyst used in the comparative example are shown in Table 4, the operating conditions used are shown in Table 5, and the specific reaction results are shown in Table 6.

Comparative examples 3 to 4

The difference from example 7 is that: the catalyst bed layer L1 used catalysts Gc and Hc, respectively, in place of catalyst M1.

Comparative example 5

The difference from example 7 is that: the catalyst bed layer L1 is not arranged, and the catalyst is replaced by a hydrodenitrogenation/carbon residue removal catalyst.

TABLE 2 Properties of the raw materials

Item	Starting materials A
		S， wt%	3.41
N，μg/g	4181
		Carbon Residue (CCR), wt%	14.31
Density (20 ℃), kg/m³	993.8
		Viscosity (100 ℃ C.), mm²/s	143
Ni+V，µg/g	124
		Fe，µg/g	26.3
Ca，µg/g	23.1

TABLE 3 catalyst loading in examples 7-12 and comparative examples 3-5

	R1	R2	R3	R4
					Example 7	FZC-100B：FZC-12B ：FZC-13B =2:3:4	FZC-28A: FZC-204=4:1	FZC-33B：FZC-34A=6:4	FZC-41A: M1=4:1
Example 8	FZC-100B：FZC-12B ：FZC-13B =2:3:4	FZC-28A: FZC-204=4:1	FZC-33B：FZC-34A=6:4	FZC-41A: M2=4:1
					Example 9	FZC-100B：FZC-12B ：FZC-13B =2:3:4	FZC-28A: FZC-204=4:1	FZC-33B：FZC-34A=6:4	FZC-41A: M3=4:1
Example 10	FZC-100B：FZC-12B ：FZC-13B =2:3:4	FZC-28A: FZC-204=4:1	FZC-33B：FZC-34A=6:4	FZC-41A: M4=4:1
					Example 11	FZC-100B：FZC-12B ：FZC-13B =2:3:4	FZC-28A: FZC-204=4:1	FZC-33B：FZC-34A=6:4	FZC-41A: M5=4:1
Example 12	FZC-100B：FZC-12B ：FZC-13B =2:3:4	FZC-28A: FZC-204=4:1	FZC-33B：FZC-34A=6:4	FZC-41A: M6=4:1
					Comparative example 3	FZC-100B：FZC-12B ：FZC-13B =2:3:4	FZC-28A: FZC-204=4:1	FZC-33B：FZC-34A=6:4	FZC-41A: Gc=4:1
Comparative example 4	FZC-100B：FZC-12B ：FZC-13B =2:3:4	FZC-28A: FZC-204=4:1	FZC-33B：FZC-34A=6:4	FZC-41A: Hc=4:1
					Comparative example 5	FZC-100B：FZC-12B ：FZC-13B =2:3:4	FZC-28A: FZC-204=4:1	FZC-33B：FZC-34A=6:4	FZC-41A

TABLE 4 Properties of the catalysts used in the comparative examples of the present invention

Catalyst type	FZC-41A
		Particle shape	All-grass of Tetrastigma
Particle diameter/mm	1.20
		Length of particles/mm	9.0
Strength/N. (mm)^-1	25.6
		Specific surface area/m².g^-1	240
Pore volume/cm³.g^-1	0.44
		Wear rate/wt%	0.75
Chemical composition/wt%
		MoO₃	18.31
NiO	5.42

TABLE 5 operating conditions for the respective examples and comparative examples

Name (R)	Example 7	Example 8	Example 9	Example 10	Example 11	Example 12
							Residual oil feedstock	Starting materials A	Starting materials A	Starting materials A	Starting materials A	Starting materials A	Starting materials A
Reaction pressure, MPa	16.5	16.5	16.5	16.5	16.5	17.5
							Liquid hourly volume space velocity, h^-1	0.25	0.25	0.25	0.25	0.25	0.18
Volume ratio of hydrogen to oil	680	680	680	680	680	800
							Reaction temperature of
R1	390	390	390	390	390	370
							R2	390	390	390	390	390	370
R3	390	390	390	390	390	370
							R4	390	390	390	390	390	370

TABLE 5 operating conditions of examples and comparative examples

Name (R)	Comparative example 3	Comparative example 4	Comparative example 5
				Residual oil feedstock	Starting materials A	Starting materials A	Starting materials A
Reaction pressure, MPa	16.5	16.5	16.5
				Liquid hourly volume space velocity, h^-1	0.25	0.25	0.25
Volume ratio of hydrogen to oil	680	680	680
				Reaction temperature of
R1	390	390	390
				R2	390	390	390
R3	390	390	390
				R4	390	390	390

TABLE 6 Properties of the oils formed by hydrogenation of the various residues

	Example 7	Example 8	Example 9	Example 10	Example 11	Example 12
							Running time, h	5000	5000	5000	5000	5000	5000
Density (20 ℃ C.), g/cm³	934.7	930.8	933.5	937.1	932.5	930.8
							S，wt%	0.36	0.33	0.37	0.39	0.36	0.30
N，µg.g^-1	1640	1570	1630	1730	1620	1440
							CCR，wt%	4.56	4.4	4.66	5.23	4.62	4.13
Ni＋V，µg.g^-1	10	9	10.3	12	10.3	10.4
							Fe，µg.g^-1	2.1	1.9	2.2	2.9	2	2.0
Ca，µg.g^-1	1.4	1.3	1.2	2	1.2	2.0
							Total pressure drop of bed layer, MPa	1.44	1.37	1.42	1.46	1.43	1.34

TABLE 6 Properties of the oils formed by hydrogenating the residues

	Comparative example 3	Comparative example 4	Comparative example 5
				Running time, h	5000	5000	5000
Density (20 ℃ C.), g/cm³	937.7	938.1	936.2
				S，wt%	0.41	0.41	0.40
N，µg.g^-1	1870	1890	1860
				CCR，wt%	5.09	5.12	5.06
Ni＋V，µg.g^-1	12.8	12.9	12.3
				Fe，µg.g^-1	6.5	6.6	6.3
Ca，µg.g^-1	5.5	5.7	5.3
				Total pressure drop of bed layer, MPa	1.6	1.62	1.75

As can be seen from Table 6, by using the catalyst M and the grading loading method of the invention, the impurity removal rate is higher and the bed pressure drop is smaller, especially iron and calcium are effectively removed, and the total bed pressure drop is effectively reduced. When the catalyst Gc or Hc is adopted in the catalyst bed layer L1, the hydrotreating catalyst has no channel, so that the residual oil diffusion path is prolonged, the activity is influenced, and simultaneously, impurities such as deposited carbon deposit occupy more inter-particle space due to the lack of impurity-containing volume carbon space of a conical pore channel, so that the bed layer void ratio is reduced, the pressure drop is increased, and the activity and the service life of the catalyst are influenced. And when the catalyst bed layer L1 adopts the conventional denitrification/carbon residue removal catalyst in the field, the iron and calcium impurities in the residual oil raw material cannot be effectively removed. Therefore, the catalyst grading method is particularly suitable for treating residual oil with high content of iron and calcium impurities, can effectively remove and attach the iron and/or calcium impurities, has high overall activity of the catalyst, and can reduce bed pressure drop and prolong the operation period of the device.

Claims

1. A catalyst grading method is characterized in that a hydrogenation protective agent bed layer, a hydrogenation demetalization catalyst bed layer and a hydrogenation desulfurization catalyst bed layer are sequentially filled in a plurality of hydrogenation reactors connected in series according to a material flow direction, the rear part of the hydrogenation denitrification and/or carbon residue removal catalyst bed layer is connected with a hydrogenation denitrification and/or carbon residue removal catalyst bed layer, a catalyst bed layer L1 filled with at least one hydrogenation treatment catalyst M is arranged behind the hydrogenation denitrification and/or carbon residue removal catalyst bed layer, the hydrogenation treatment catalyst M comprises a carrier and hydrogenation active metal components, the carrier is a sphere, the diameter of the carrier is 2.5-8.0 mm, the outer surface of the carrier is provided with a plurality of large pores which are not communicated, the sectional area of the large pores is gradually reduced from outside to inside along the radial direction, the area of the bottom surface of each large pore is 0.05-5% of the surface area of the sphere, the area of the total bottom surface of the large pores is 5-50, the longest depth of the large pore channel is 30-99% of the radius of the spherical carrier, and preferably 55-96% of the length of the pore channel along the radius direction of the sphere.

2. The method of claim 1, wherein the loading volume of the catalyst in the catalyst bed L1 is 2% to 15%, preferably 5% to 10%, of the total loading volume of the catalyst in all hydrogenation reactors.

3. The method according to claim 1, wherein the hydrotreating catalyst M has macropores extending from the outer surface toward the center of the sphere.

4. The method of claim 1, wherein the bottom surface of the macro-channels in the hydrotreating catalyst M is at least one of circular, elliptical, polygonal, and irregular on the outer surface of the sphere.

5. The method according to claim 4, wherein the macropores in the hydrotreating catalyst M are conical or pyramidal, and preferably, the angle of the vertex angle of the conical or pyramidal pore is 5 to 50 degrees.

6. The process according to claim 1, wherein the minimum cross-sectional area of the macropores in the hydrotreating catalyst M is 10% or less, preferably 5% or less, and more preferably 2% or less of the area of the bottom surface of the macropores.

7. The method of claim 1, wherein the cross-sectional area of the macro-channels from the bottom to the longest depth 1/2 in the hydrotreating catalyst M is 20% to 70%, preferably 25% to 65%, of the area of the bottom of the macro-channels.

8. The process of claim 1, wherein the cross-sectional area of the macro-channels from the bottom to the longest depth 1/2 is 30% to 80%, preferably 45% to 75%, of the cross-sectional area from the bottom to the longest depth 1/4 in the hydroprocessing catalyst M.

9. The process of claim 1, wherein the cross-sectional area of the macro-channels from the bottom to the longest depth 3/4 is 40% to 80%, preferably 55% to 75%, of the cross-sectional area from the bottom to the longest depth 1/2 in the hydroprocessing catalyst M.

10. The process according to claim 1, wherein the width of the largest cross-section of the macropores in the hydroprocessing catalyst M does not exceed 30 μ M.

11. The method according to claim 1, wherein in the hydrotreating catalyst M, the distribution of macropores on the surface of the carrier is realized, wherein the minimum wall thickness between any two adjacent macropores accounts for 1/8-1/5 of the diameter of a sphere; preferably, the macropores on the surface of the carrier are the same; preferably, the macropores of the carrier are uniformly distributed on the surface of the sphere.

12. The method of claim 1, wherein the carrier of the hydrotreating catalyst M is spherical, and has conical large channels with the apex pointing to the center of the sphere and the bottom on the surface of the sphere, the diameter of the spherical carrier is 2.5 to 8.0mm, wherein the area of the bottom of each conical large channel is 0.05 to 4.5% of the surface area of the sphere, the area of the total bottom of the conical large channels is 5 to 50% of the surface area of the sphere, the height of each conical large channel is 50 to 99%, preferably 55 to 96%, of the radius of the spherical carrier, the angle of the apex angle of each conical large channel is 5 to 50%, and the conical channels of the carrier are uniformly distributed on the surface of the sphere.

13. The method as claimed in claim 12, wherein the carrier of the hydrotreating catalyst M is provided with 4 to 40, preferably 8 to 40, conical macropores.

14. The process according to claim 1, characterized in that the support of the hydrotreating catalyst M is Al₂O₃-SiO₂As a carrier, wherein SiO₂The weight content is 20-50%, preferably 30-40%.

15. The method of claim 14, wherein the carrier of the hydrotreating catalyst M further contains a first metal component oxide, and the first metal component oxide is NiO; the first metal component oxide NiO and Al₂O₃Is 0.03: 1-0.13: 1, preferably 0.05: 1-0.11: 1.

16. the method according to any one of claims 1 to 15, wherein the hydrotreating catalyst M carrier has the following properties: the specific surface area is 100-200 m²The pore volume is more than 0.70mL/g, preferably 0.75-1.15 mL/g, the pore volume occupied by the pore diameter of 20-100 nm is 35-60% of the total pore volume, and the average pore diameter is more than 15nm, preferably 17-30 nm.

17. The process according to claim 1, wherein the active metal component of the hydrotreating catalyst M comprises a second metal component, i.e. a group vib metal element, preferably Mo, and a third metal component, i.e. a group viii metal element, preferably Ni and/or Co.

18. The method of claim 17, wherein the second metal component is present in an amount of 1.0% to 30.0%, preferably 1.5% to 20%, calculated as oxide, based on the weight of the catalyst, the total amount of the first metal component and the third metal component is present in an amount of 1.0% to 35.0%, preferably 2.0% to 25.0%, calculated as oxide, the amount of silica is 25.0% to 35.0%, and the amount of alumina is 55.0% to 65.0%.

19. A residual oil hydrotreating method is characterized in that under the hydrotreating reaction condition, a residual oil raw material and hydrogen sequentially pass through a plurality of serially connected hydrogenation reactors, and contact with a catalyst loaded in the hydrogenation reactor according to the grading method of any one of claims 1 to 18 to carry out hydrogenation reaction, so as to obtain a hydrotreating product.

20. The process of claim 19, wherein the operating conditions of each reactor are, independently: the reaction pressure is 5-25 MPa, the reaction temperature is 300-430 ℃, and the liquid hourly space velocity is 0.05-5.0 h^-1The volume ratio of hydrogen to oil is 150: 1-1000: 1.

21. The process of claim 19, wherein the residua feedstock contains iron and/or calcium, and wherein the organic and inorganic iron content, as iron, is 10 μ g/g or more, further 20 μ g/g or more, and the calcium content is 10 μ g/g or more, further 20 μ g/g or more.