CN111196935B

CN111196935B - Grading method of hydrotreating catalyst

Info

Publication number: CN111196935B
Application number: CN201811368407.4A
Authority: CN
Inventors: 赵元生; 赵愉生; 张志国; 张天琪; 程涛; 于双林; 宋俊男; 张春光; 由慧玲; 张晓�; 王小丹; 姚远
Original assignee: Petrochina Co Ltd
Current assignee: Petrochina Co Ltd
Priority date: 2018-11-16
Filing date: 2018-11-16
Publication date: 2022-02-01
Anticipated expiration: 2038-11-16
Also published as: CN111196935A

Abstract

本发明涉及一种加氢处理催化剂级配方法，用于重质油的加氢处理，反应器自上而下依次装填加氢脱金属催化剂、加氢脱硫催化剂，原料物流自上而下，保持沿物流方向，催化剂活性逐渐增大，孔径逐渐减小，粒度逐渐减小，孔隙率逐渐减小；所述加氢脱金属催化剂和所述加氢脱硫催化剂分别由一种或多种催化剂组成，硫化后的加氢脱金属催化剂和加氢脱硫催化剂中的活性金属MoS₂呈高度分散分布，硫化后的加氢脱金属催化剂中MoS₂以单层和双层分散为主，硫化后的加氢脱硫催化剂中MoS₂以多层为主。该方法得到的催化剂级配组合的脱金属、脱残炭、脱硫、脱氮活性和稳定性较高，使用寿命长。The invention relates to a hydrotreating catalyst grading method, which is used for the hydrotreating of heavy oil. The reactor is filled with a hydrodemetallization catalyst and a hydrodesulfurization catalyst in sequence from top to bottom. Along the flow direction, the catalyst activity gradually increases, the pore size gradually decreases, the particle size gradually decreases, and the porosity gradually decreases; the hydrodemetallization catalyst and the hydrodesulfurization catalyst are respectively composed of one or more catalysts, _The active metal MoS ₂ in the hydrodemetallization catalyst and hydrodesulfurization catalyst after sulfidation is highly dispersed. _MoS2 in the desulfurization catalysts is dominated by multilayers. The catalyst gradation combination obtained by the method has high demetallization, carbon residue removal, desulfurization and denitrification activity and stability, and has a long service life.

Description

Grading method of hydrotreating catalyst

Technical Field

The invention relates to a grading method of a hydrotreating catalyst, in particular to a grading method of a hydrotreating catalyst for hydrofining and hydrotreating of heavy oil.

Background

The shortage and deterioration of global petroleum resources lead to the continuous increase of the proportion of heavy crude oil and high-sulfur crude oil in the crude oil market; meanwhile, with the rapid development of economy and the stricter environmental regulations in China, the market demand for clean oil products is also rapidly increased, and the position of a hydrogenation process in a refinery is more and more important. The development of novel hydrogenation catalysts for realizing deep hydrogenation treatment of oil products has become an urgent need in the aspect of hydrogenation treatment at present.

In the process of hydrotreating heavy distillate oil, especially residual oil, because the raw material has high impurity content, especially the oil soluble organic metal compounds of nickel, vanadium, etc. have strong poisoning effect on the hydrodesulfurization and denitrification catalysts, the prior art proposes various methods for removing such impurities from the feed so as to protect the downstream high-activity hydrodesulfurization and denitrification catalysts. For example, U.S. patent No. USP 4447314 teaches a two catalyst bed system hydrotreating process for residua using a first catalyst that is a large pore catalyst and a second catalyst that is a small pore catalyst. In the residual oil hydrogenation process, raw oil firstly passes through a first catalyst bed layer, and then sequentially passes through a second catalyst positioned at the downstream of the first catalyst, so that the demetallization and desulfurization of residual oil are realized. US4306964 proposes a method of sequentially loading three catalysts at different parts of a reactor to solve the above problems.

CN 1197105A discloses a process for hydrotreating metal-contaminated hydrocarbonaceous feedstocksA process wherein at least 60 wt% of the hydrocarbonaceous feedstock has a boiling temperature of at least 370 ℃, which process comprises: contacting the feedstock with one or more catalyst beds of a first catalyst, a second catalyst and a third catalyst in the presence of hydrogen at elevated temperature and elevated pressure, wherein (i) the first catalyst comprises a group VI and/or group VIII hydrogenation metal component supported on an inorganic oxide support, has at least 40% of its pore volume in the range of pore diameters 17-25nm, and has a surface area in the range of 100-²In the range of/g; (ii) the second catalyst comprises a group VI and/or group VIII hydrogenation metal component supported on an inorganic oxide support, having at least 40% of its pore volume in the range of pore diameters from 3 to 17nm and a surface area of 160-350m²In the range of/g; (iii) the third catalyst comprises a group VI and/or group VIII hydrogenation metal component supported on an inorganic oxide support, at least 40% of the pore volume of which is in the range of pore diameter 17-25nm, and the surface area of which is 100-160m²In the range of/g; wherein the demetallization activity of the third catalyst is at least 1.5 times that of the first catalyst in the case where the contaminant metal deposition amount is less than 5% by weight.

CN 1313379A discloses a hydrotreating method of inferior catalytic cracking raw material, which is to contact the raw material with hydrogenation protective agent, hydrogenation demetalization catalyst and hydrogenation refining catalyst in turn, under the conditions that the hydrogen partial pressure is 5.0-10.0 MPa, the temperature is 330-420 ℃, the volume ratio of hydrogen to oil is 300-1000: 1, and the liquid hourly space velocity is 0.2-1.2 hours^-1The reaction with hydrogen, cooling and separating the effluent after reaction, recycling the hydrogen-containing gas, and allowing the liquid product to enter a fractionation system. The contents of sulfur, nitrogen and metal in the raw material are all reduced after hydrogenation, and the raw material can be directly used as a catalytic cracking raw material.

CN 1100122C discloses a hydrogenation technology for hydrotreating poor quality gas oil to produce catalytic cracking feed. The patent adopts a catalyst combination of a hydrogenation protective agent/a hydrodemetallization agent/a hydrofining catalyst, so that the metal content, the sulfur content and the nitrogen content of the inferior gas oil raw material are greatly reduced, and the requirements of a catalytic cracking device on feeding can be met. But the volume space velocity of the patent is low and is 0.2-1.2 h^-1And therefore the processing cost is high.

CN 1197105a discloses a process for hydrotreating a hydrocarbon feedstock containing metal contaminants; the method comprises the step of contacting the raw material with one or more catalyst beds of a first catalyst, a second catalyst and a third catalyst in the presence of hydrogen. The catalysts in each bed layer have different properties and functions. In fact, along the material flow direction, the catalyst activity gradually increases, the pore diameter gradually decreases, and the method is a conventional hydrotreating process of firstly removing metals, then removing sulfur, and finally removing nitrogen. Tests prove that the graded filling method has the defects that the temperature rise of a desulfurization and denitrification catalyst bed is overlarge, the cold hydrogen requirement is large, and the treatment capacity cannot be improved.

CN1054393C 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 carrier has a pore volume of 0.80-1.20 ml/g (mercury intrusion method) and a specific surface area of 110-200 m²(ii) a pore diameter of 15 to 20nm and a bulk density of 0.50 to 0.60 g/ml. The method of the invention is that in the process of kneading pseudo-boehmite, physical pore-enlarging agent and chemical pore-enlarging agent are added at the same time, and then the mixture is kneaded into plastic body, extruded into strips, formed, dried and roasted to obtain carrier, then the active component is added on the carrier by means of spraying and dipping, and finally the catalyst is obtained after drying and roasting. The large-aperture catalyst for residual oil hydrogenation disclosed by the invention is suitable for the residual oil hydrogenation demetalization process, but the catalyst is low in hydrogenation active component content, poor in polycyclic aromatic hydrocarbon hydrogenation saturation capacity, weak in acidity and weak in hydrogenation conversion capacity.

In general, the main disadvantage of the prior art is that the catalyst utilization rate in the grading system is not high, and the prior catalyst grading combination system needs to be further optimized.

Disclosure of Invention

The invention aims to provide a hydrotreating catalyst grading method which can effectively exert the functions of various catalysts and improve the activity and stability of demetalization, desulfurization and carbon residue removal of the catalyst.

Therefore, the invention provides a grading method of a hydrotreating catalyst, which is used for hydrotreating heavy oil,

the reactor is sequentially filled with a hydrodemetallization catalyst (HDM) and a hydrodesulfurization catalyst (HDS) from top to bottom, the material flow is from top to bottom, the catalyst activity is gradually increased, the average pore diameter is gradually reduced, the particle size is gradually reduced, and the porosity is gradually reduced along the material flow direction;

the hydrodemetallization catalyst and the hydrodesulfurization catalyst are respectively and independently composed of one or more catalysts, and the active metal MoS in the hydrodemetallization catalyst and the hydrodesulfurization catalyst after vulcanization₂In a highly dispersed distribution, and the MoS in the hydrogenated demetallization catalyst after vulcanization₂Mainly comprises single-layer and double-layer dispersions, the average layer number of the single-layer and double-layer dispersions is between 1.0 and 2.5 and accounts for 85 to 95 percent, and MoS in the vulcanized hydrodesulfurization catalyst₂The multilayer is taken as the main, and the average layer number is 2.5-4 layers accounting for 80-95%;

in the catalyst grading combination, the hydrodemetallization catalyst accounts for 15-80% by weight, and the hydrodesulfurization catalyst accounts for 20-85% by weight.

In the catalyst grading method for hydrotreating of the present invention, the hydrodemetallization catalyst preferably accounts for 20% to 50% and the hydrodesulfurization catalyst preferably accounts for 50% to 80% by weight of the catalyst grading composition.

In the method for grading a hydrotreating catalyst according to the present invention, it is preferable that MoS in the sulfurized hydrodemetallization catalyst is₂The average layer number of the layers is 50-65% between 1.5-2; MoS in the sulfurized hydrodesulfurization catalyst₂The average number of layers is 50-65% in 3-4 layers.

In the method of the invention, the hydrodemetallization agent and the hydrodesulfurization agent can be prepared by adopting a conventional method in the field.

The hydrotreating catalyst grading method of the present invention is preferably a dry presulfurization or a wet sulfidization, wherein the sulfidation processes of the hydrodemetallization catalyst and the hydrodesulfurization catalyst are independent from each other.

The invention relates to a grading method of a hydrotreating catalystWherein, the vulcanizing agent in the vulcanizing process of the hydrodemetallization catalyst and the hydrodesulfurization catalyst are respectively and independently selected from H₂S, at least one of thiol, disulfide, polysulfide, and thiophenecarboxylic acid compounds; further preferably selected from H₂At least one of S, carbon disulfide, dimethyl sulfide and dimethyl disulfide.

In the method for grading a hydrotreating catalyst, the hydrodemetallization catalyst preferably uses an inorganic oxide as a carrier and a group VIB metal and/or a group VIII metal as an active component.

In the method for grading a hydrotreating catalyst according to the present invention, it is preferable that the hydrodemetallization catalyst further includes an auxiliary agent, and the auxiliary agent is at least one selected from P, Si, F, and B.

The hydrodemetallization catalyst described above may consist of one or more catalysts.

In the method for grading a hydrotreating catalyst, the hydrodesulfurization catalyst preferably uses an inorganic oxide as a carrier and a group VIB metal and/or a group VIII metal as an active component.

In the method for grading a hydrotreating catalyst according to the present invention, it is preferable that the hydrodesulfurization catalyst further includes an auxiliary agent, and the auxiliary agent is at least one selected from P, Si, F, and B.

The hydrodesulfurization catalyst may consist of one or more catalysts.

The hydrotreating catalyst grading method of the present invention is characterized in that the inorganic oxide is preferably at least one selected from alumina and silica, the group VIB metal is preferably at least one selected from W and Mo, and the group VIII metal is preferably at least one selected from Co and Ni.

More preferably, the above-mentioned hydrotreating catalysts (i.e., hydrodemetallization catalyst and hydrodesulfurization catalyst) used in the catalyst grading process of the present invention have a bulk density of 0.3 to 1.2g/mL and a specific surface area of 50 to 400m²Per g, for example, the PHR series of the institute of petrochemical engineering in China can be usedA catalyst.

The hydrotreating catalyst grading method of the present invention is characterized in that the conditions for hydrotreating the heavy oil are preferably: hydrogen pressure of 5.0 MPa-20.0 MPa, temperature of 300-450 deg.c and liquid hourly space velocity of 0.2 hr^-1～5^-1The volume ratio of hydrogen to oil is 300-2500.

In the method for grading a hydrotreating catalyst according to the present invention, the conditions for hydrotreating the heavy oil are more preferably: hydrogen pressure of 8.0MPa to 18.0MPa, temperature of 330 ℃ to 440 ℃, liquid hourly volume space velocity of 0.2h^-1～3h^-1The volume ratio of hydrogen to oil is 400-2000.

In the method for grading a hydrotreating catalyst according to the present invention, the conditions for hydrotreating the heavy oil are preferably: hydrogen pressure of 10.0MPa to 16.0MPa, temperature of 350 ℃ to 430 ℃, liquid hourly volume space velocity of 0.2h^-1～2h^-1The volume ratio of hydrogen to oil is 500-1500.

In the process of the present invention, the hydrodemetallization catalyst and the hydrodesulfurization catalyst may be selected from commercial catalysts conventional in the art or prepared by conventional methods of the prior art.

The grading method can be used in a conventional fixed bed hydrogenation device, in the actual use process of the grading method, a heavy oil raw material and hydrogen are mixed and then enter the hydrogenation device, and sequentially pass through a support protective agent, a hydrodemetallization catalyst and a hydrodesulfurization catalyst, and oil gas after reaction enters a subsequent separation device for separation. The process flow for hydrotreating is well known to those skilled in the art.

The invention provides a hydrogenation catalyst grading method capable of effectively playing the role of various catalysts, and the catalyst grading combination has high activity and stability of demetalization, desulfurization and carbon residue removal and long service life. The method can effectively control the temperature rise of the catalyst bed layer, slow down the deactivation speed of the catalyst and prolong the operation period of the catalyst.

Detailed Description

The following examples illustrate the invention in detail: the present example is carried out on the premise of the technical scheme of the present invention, and detailed embodiments and processes are given, but the scope of the present invention is not limited to the following examples, and the experimental methods without specific conditions noted in the following examples are generally performed according to conventional conditions.

The grading method of the hydrotreating catalyst provided by the invention is used for hydrotreating heavy oil,

In the catalyst grading combination, the hydrodemetallization catalyst accounts for 20-50% by weight, and the hydrodesulfurization catalyst accounts for 50-80% by weight.

Wherein MoS in the vulcanized hydrodemetallization catalyst₂The average layer number of the layers is 50-65% between 1.5-2; MoS in the sulfurized hydrodesulfurization catalyst₂The average number of layers is 50-65% in 3-4 layers.

Wherein, the sulfurization processes of the hydrodemetallization catalyst and the hydrodesulfurization catalyst are respectively and independently dry pre-sulfurization or wet sulfurization.

Wherein, the vulcanizing agents in the process of vulcanizing the hydrodemetallization catalyst and the hydrodesulfurization catalyst are respectively and independently selected from H₂S, at least one of thiol, disulfide, polysulfide, and thiophenecarboxylic acid compounds; is further selected from H₂At least one of S, carbon disulfide, dimethyl sulfide and dimethyl disulfide.

The hydrodemetallization catalyst takes an inorganic oxide as a carrier and a VIB group metal and/or VIII group metal as an active component.

The hydrodemetallization catalyst also comprises an auxiliary agent, and the auxiliary agent is selected from at least one of P, Si, F and B.

The hydrodesulfurization catalyst takes inorganic oxide as a carrier and takes VIB group metal and/or VIII group metal as an active component.

The hydrodesulfurization catalyst also comprises an auxiliary agent, wherein the auxiliary agent is at least one selected from P, Si, F and B.

The hydrodesulfurization catalyst may consist of one or more catalysts.

Wherein, the inorganic oxide is preferably selected from at least one of alumina and silica, the VIB group metal is preferably selected from at least one of W and Mo, and the VIII group metal is preferably selected from at least one of Co and Ni.

The bulk density of the hydrotreating catalyst (i.e. hydrodemetallization catalyst and hydrodesulfurization catalyst) used in the catalyst grading method of the invention is 0.3-1.2g/mL, and the specific surface area is 50-400m²For example, PHR series commercial catalysts developed by the institute of petrochemical engineering, China can be used.

In some embodiments, the conditions for hydrotreating of the heavy oil are: hydrogen pressure of 5.0 MPa-20.0 MPa, temperature of 300-450 deg.c and liquid hourly space velocity of 0.2 hr^-1～5h^-1The volume ratio of hydrogen to oil is 300-2500.

In other embodimentsThe conditions for the hydrotreatment of the heavy oil are as follows: hydrogen pressure of 8.0MPa to 18.0MPa, temperature of 360 ℃ to 440 ℃, liquid hourly volume space velocity of 0.2h^-1～3h^-1The volume ratio of hydrogen to oil is 400-2000.

In other embodiments, the conditions for hydrotreating of the heavy oil are: hydrogen pressure of 10.0MPa to 16.0MPa, temperature of 360 ℃ to 430 ℃, liquid hourly volume space velocity of 0.2h^-1～2h^-1The volume ratio of hydrogen to oil is 500-1500.

In the method of the present invention, the hydrodemetallization agent and the hydrodesulfurization agent can be prepared by using commercial catalysts or conventional methods in the prior art.

The grading method can be used in a conventional fixed bed hydrogenation device, in the actual use process of the grading method, a heavy oil raw material and hydrogen are mixed and then enter the hydrogenation device, and sequentially pass through a protective agent, a hydrodemetallization agent and a desulfurization catalyst, and oil gas after reaction enters a subsequent separation device for separation.

The properties of the catalysts used in the following examples and comparative example grading are shown in table 1.

TABLE 1 catalyst Properties

Example 1

This example shows the preparation of a catalyst grading combination.

The catalyst grading assembly scheme is adopted, a plurality of catalysts are filled in a reactor, the material flow is kept along the material flow direction from top to bottom, a hydrodemetallization catalyst HDM-1 and a hydrodesulfurization catalyst HDS-1 are respectively filled in a bed layer from top to bottom, and the mass ratio of the added catalysts is 45% and 55% respectively.

The average pore diameter of the hydrodemetallization catalyst HDM-1 is 22.61nm, and the average particle size is 3.5 mm; the average pore diameter of the HDS-1 hydrodesulfurization catalyst was 11.01nm and the average particle diameter was 1.5 mm. When the catalyst is filled, the catalyst is kept along the material flow direction, the activity of the catalyst is gradually increased, the average pore diameter is gradually reduced, the particle size is gradually reduced, and the porosity is gradually reduced.

Then, the mixture is vulcanized by a wet method, and the vulcanizing agent is CS₂The addition amount is 2.0 wt%, and the vulcanized oil is normal quadri-line diesel oil. Hydrogen passes through once, the vulcanization condition is that the temperature is kept constant at 280 ℃ for 20h, then the temperature is kept constant at 320 ℃ for 8h, and the heating rate is 10 ℃/h;

active metal MoS in vulcanized hydrodemetallization catalyst HDM-1 and hydrodesulfurization catalyst HDS-1₂In a highly dispersed distribution, and MoS in the hydrogenated demetallization catalyst HDM-1 after vulcanization₂Mainly comprises single-layer and double-layer dispersions, the average layer number is 91.7 percent between 1.0 and 2.5, wherein the layer number is 63.2 percent between 1.5 and 2.0, and MoS in the vulcanized hydrodesulfurization catalyst HDS-1₂The multilayer is mainly used, the average layer number is 2.5-4 and accounts for 88.1%, wherein, the layer number is 51.3% between 3.0-4.0.

Comparative example 1

The catalyst grading assembly scheme is adopted, a plurality of catalysts are filled in a reactor, a bed layer is respectively filled with a hydrodemetallization catalyst HDM-1P and a hydrodesulfurization catalyst HDS-1P from top to bottom, and the adding mass ratio is 45% and 55% respectively.

The average pore diameter of the hydrodemetallization catalyst HDM-1P is 22.07nm, and the average particle size is 3.5 mm; the average pore diameter of the hydrodesulfurization catalyst HDS-1P was 11.06nm, and the average particle diameter was 1.5 mm. When the catalyst is filled, the catalyst is kept along the material flow direction, the activity of the catalyst is gradually increased, the pore diameter is gradually reduced, the particle size is gradually reduced, and the porosity is gradually reduced.

The vulcanization conditions were the same as in example 1.

Active metal MoS in vulcanized hydrodemetallization catalyst HDM-1P and hydrodesulfurization catalyst HDS-1P₂Is not highly dispersed and is not distributed, and MoS in the hydrogenated demetallization catalyst HDM-1P after vulcanization₂The average layer number is only 41.2% between 1.0 and 2.5, wherein the layer number is only 33.7% between 1.5 and 2.0, after vulcanizationIn the hydrodesulfurization catalyst HDS-1P₂And the average layer number is 2.5-4, and is only 35.6%, wherein the average layer number is only 23.1% between 3.0-4.0.

Example 2

This example shows the preparation of a catalyst grading combination.

The catalyst grading assembly scheme is adopted, a plurality of catalysts are filled in a reactor, a bed layer is respectively filled with a hydrodemetallization catalyst HDM-2 and a hydrodesulfurization catalyst HDS-2 from top to bottom, and the adding mass ratio is respectively 35% and 65%.

The average pore diameter of the hydrodemetallization catalyst HDM-2 is 20.67nm, and the average particle size is 2.2 mm; the average pore diameter of the HDS-2 hydrodesulfurization catalyst was 9.71nm and the average particle diameter was 1.2 mm. When the catalyst is filled, the catalyst is kept along the material flow direction, the activity of the catalyst is gradually increased, the pore diameter is gradually reduced, the particle size is gradually reduced, and the porosity is gradually reduced.

The wet vulcanization is adopted, dimethyl disulfide (DMDS) is used as a vulcanizing agent, the addition amount is 2.0 wt%, and straight-run diesel is used as vulcanized oil. The hydrogen passes through the reactor once, the vulcanization condition is that the temperature is kept constant at 230 ℃ for 10h, at 280 ℃ for 8h, at 320 ℃ for 8h, and the heating rate is 15 ℃/h.

Active metal MoS in vulcanized hydrodemetallization catalyst HDM-2 and hydrodesulfurization catalyst HDS-2₂Is in high dispersion distribution, and MoS in the hydrogenated demetallization catalyst HDM-2 after vulcanization₂Mainly comprises single-layer and double-layer dispersions, the average layer number is 86.5 percent between 1.0 and 2.5, wherein the layer number is 52.3 percent between 1.5 and 2.0, and MoS in the vulcanized hydrodesulfurization catalyst HDS-2₂The multilayer is taken as the main material, the average layer number is 2.5-4 layers accounting for 83.3%, wherein, the layer number is between 3.0-4.0 accounting for 63.5%.

Comparative example 2

This example shows the preparation of a catalyst grading combination.

The catalyst grading assembly scheme is adopted, a plurality of catalysts are filled in a reactor, a hydrodemetallization catalyst HDM-2P and a hydrodesulfurization catalyst HDS-2P are respectively filled in a bed layer from top to bottom, and the adding mass ratio is respectively 35% and 65%.

The average pore diameter of the hydrodemetallization catalyst HDM-2P is 19.83nm, and the average particle size is 2.2 mm; the average pore diameter of the hydrodesulfurization catalyst HDS-2P was 9.30nm and the average particle diameter was 1.2 mm. When the catalyst is filled, the catalyst is kept along the material flow direction, the activity of the catalyst is gradually increased, the pore diameter is gradually reduced, the particle size is gradually reduced, and the porosity is gradually reduced.

The vulcanization conditions were the same as in example 2.

Sulfurized hydrodemetallization catalyst HDM-2P and active metal MoS in hydrodemetallization catalyst HDS-2P₂Is not highly dispersed and is not distributed, and MoS in the hydrogenated demetallization catalyst HDM-2P after being vulcanized₂The average layer number is only 35.7% between 1.0 and 2.5, wherein the layer number is only 25.1% between 1.5 and 2.0, and MoS in the vulcanized hydrodesulfurization catalyst HDS-2P₂The average number of layers is not mainly multilayer, and the number of layers is only 31.2% in the range of 2.5-4, wherein the number of layers is only 21.7% in the range of 3.0-4.0.

Example 3

This example shows the preparation of a catalyst grading composition.

The catalyst grading assembly scheme is adopted, a plurality of catalysts are filled in a reactor, hydrodemetallization catalysts (HDM-1 and HDM-2, the mass ratio of the HDM-1 to the HDM-2 is 1:1) and hydrodesulfurization catalysts (HDS-1 and HDS-2, the mass ratio of the HDS-1 to the HDS-2 is 1:1) are respectively filled in a bed layer from top to bottom, and the mass ratio of the hydrodemetallization catalysts to the hydrodesulfurization catalysts is 25% and 75% respectively.

The average pore diameter of the hydrodemetallization catalyst HDM-1 is 22.61nm, and the average particle size is 3.5 mm; the average pore diameter of the hydrodemetallization catalyst HDM-2 is 20.67nm, and the average particle size is 2.2 mm; the average pore diameter of the hydrodesulfurization catalyst HDS-1 is 11.01nm, and the average particle size is 1.5 mm; the average pore diameter of the HDS-2 hydrodesulfurization catalyst was 9.71nm and the average particle diameter was 1.2 mm. When the catalyst is filled, the catalyst is kept along the material flow direction, the activity of the catalyst is gradually increased, the average pore diameter is gradually reduced, the particle size is gradually reduced, and the porosity is gradually reduced.

Adopting a dry vulcanization mode, wherein dimethyl disulfide (DMDS) is used as a vulcanizing agent, the hydrogen is fully circulated, the purity is not less than 95%, the dew point is not more than-20 ℃, the vulcanization condition is that the temperature is kept constant at 230 ℃ for 10h and at 350 ℃ for 10h, and the heating rate is 5 ℃/h.

Active metal MoS in vulcanized hydrodemetallization catalysts HDM-1 and HDM-2 and hydrodesulfurization catalysts HDS-1 and HDS-2₂In a highly dispersed distribution, and MoS in the hydrogenated demetallization catalyst HDM-1 after vulcanization₂The single-layer and double-layer dispersion is mainly used, the average layer number accounts for 91.7% between 1.0 and 2.5, wherein the average layer number accounts for 63.2% between 1.5 and 2.0; MoS in hydrogenation demetalization catalyst HDM-2 after vulcanization₂Mainly comprises single-layer and double-layer dispersions, wherein the average layer number accounts for 86.5 percent between 1.0 and 2.5 percent, and the layer number accounts for 52.3 percent between 1.5 and 2.0 percent;

MoS in vulcanized hydrodesulfurization catalyst HDS-1₂The multilayer is taken as the main material, the average layer number is 2.5-4, and accounts for 88.1%, wherein, the layer number is 51.3% between 3.0-4.0; MoS in vulcanized hydrodesulfurization catalyst HDS-2₂The multilayer is taken as the main material, the average layer number is 2.5-4 layers accounting for 83.3%, wherein, the layer number is between 3.0-4.0 accounting for 63.5%.

Comparative example 3

This example shows the preparation of a catalyst grading combination.

The catalyst grading assembly scheme is adopted, a plurality of catalysts are filled in a reactor, hydrodemetallization catalysts (HDM-1P and HDM-2P with the mass ratio of 1:1) and hydrodesulfurization catalysts (HDS-1P and HDS-2P with the mass ratio of 1:1) are respectively filled in a bed layer from top to bottom, and the mass ratio of the hydrodemetallization catalysts to the hydrodesulfurization catalysts is 25% and 75% respectively.

The average pore diameter of the hydrodemetallization catalyst HDM-1P is 22.07nm, and the average particle size is 3.5 mm; the average pore diameter of the hydrodemetallization catalyst HDM-2P is 19.83nm, and the average particle size is 2.2 mm; the average pore diameter of the hydrodesulfurization catalyst HDS-1P is 11.06nm, and the average particle size is 1.5 mm; the average pore diameter of the hydrodesulfurization catalyst HDS-2P was 9.30nm and the average particle diameter was 1.2 mm.

The vulcanization conditions were the same as in example 3.

Sulfurized hydrodemetallization catalyst HDM-1P, HDM-2PAnd the active metal MoS in the hydrodesulfurization catalyst HDS-1P, HDS-2P₂Are not highly dispersed and are not distributed, and MoS in the hydrogenated demetallization catalyst HDM-1P after being vulcanized₂The average layer number is only 41.2% between 1.0 and 2.5, wherein the average layer number is only 33.7% between 1.5 and 2.0; MoS in vulcanized hydrodemetallization catalyst HDM-2P₂The average layer number is only 35.7% between 1.0 and 2.5, wherein the average layer number is only 25.1% between 1.5 and 2.0;

MoS in vulcanized hydrodesulfurization catalyst HDS-1P₂The multilayer is not mainly used, the average layer number is 2.5-4 and only accounts for 35.6 percent, wherein, the layer number between 3.0-4.0 only accounts for 23.1 percent; MoS in vulcanized hydrodesulfurization catalyst HDS-2P₂The average number of layers is not mainly multilayer, and the number of layers is only 31.2% in the range of 2.5-4, wherein the number of layers is only 21.7% in the range of 3.0-4.0.

Example 4

This example is a comparative test of the activity and stability of the catalyst combinations of examples 1, 2, 3 and comparative examples 1, 2, 3.

The evaluation was carried out on a 300ml small fixed bed hydrogenation apparatus. The feedstock was evaluated as middle east heavy oil, and the properties thereof are shown in Table 2.

TABLE 2 Primary Properties of the test stocks

The evaluation conditions are shown in Table 3.

TABLE 3 Process conditions

The results of the activity evaluation of the catalyst combination system after 200 hours of operation are shown in Table 4.

Table 4 evaluation of Activity test results

As can be seen from table 4, the metal removal, sulfur removal, nitrogen removal and carbon removal rates of the catalyst graded combinations of examples 1, 2 and 3 are significantly higher than the corresponding comparative catalyst graded combinations.

The 5000-hour stability evaluation results are shown in Table 5.

TABLE 55000 h stability evaluation results

As can be seen from Table 5, the metal removal, sulfur removal, nitrogen removal and carbon removal rates of the catalyst grading combinations of examples 1, 2 and 3 are significantly higher than the corresponding comparative catalyst combinations as the run time was extended.

In conclusion, the invention provides a hydrogenation catalyst grading method capable of effectively playing the role of various catalysts, and the catalyst grading combination has high activity and stability in demetalization, desulfurization and carbon residue removal and long service life. The method can effectively control the temperature rise of the catalyst bed layer, slow down the deactivation speed of the catalyst and prolong the operation period of the catalyst.

The present invention is capable of other embodiments, and various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A method for grading a hydrotreating catalyst, which is used for hydrotreating heavy oil, is characterized in that,

the hydrodemetallization catalyst and the hydrodesulfurization catalyst are sequentially filled in the reactor from top to bottom, the material flow is kept along the material flow direction from top to bottom, the activity of the catalyst is gradually increased, the average pore diameter is gradually reduced, the particle size is gradually reduced, and the porosity is gradually reduced;

the hydrodemetallization catalyst and the hydrodesulfurization catalyst are each independentlyThe land is composed of one or more catalysts, the vulcanized hydrodemetallization catalyst and the active metal MoS in the hydrodemetallization catalyst₂In a highly dispersed distribution, and the MoS in the hydrogenated demetallization catalyst after vulcanization₂Mainly comprises single-layer and double-layer dispersions, the average layer number of the single-layer and double-layer dispersions is between 1.0 and 2.5 and accounts for 85 to 95 percent, and MoS in the vulcanized hydrodesulfurization catalyst₂The multilayer is taken as the main, and the average layer number is 2.5-4 layers accounting for 80-95%;

2. The hydroprocessing catalyst grading method according to claim 1, wherein the hydrodemetallization catalyst is 20-50% and the hydrodesulfurization catalyst is 50-80% by weight of the catalyst grading composition.

3. The hydroprocessing catalyst grading method according to claim 1, wherein MoS in the sulfided hydrodemetallization catalyst₂The average layer number of the layers is 50-65% between 1.5-2; MoS in the sulfurized hydrodesulfurization catalyst₂The average number of layers is 50-65% in 3-4 layers.

4. The hydroprocessing catalyst grading process according to claim 1, wherein the sulfiding process of the hydrodemetallization catalyst and the hydrodesulfurization catalyst is independently a dry presulfiding or a wet sulfiding, respectively.

5. The hydroprocessing catalyst grading method according to claim 1, wherein the sulfiding agent in the sulfiding of the hydrodemetallization catalyst and the hydrodesulfurization catalyst are each independently selected from H₂S, at least one of a thiol, polysulfide, and thiophenecarboxylic acid compound.

6. The hydroprocessing catalyst grading method according to claim 5, wherein the polysulfides are disulfides.

7. The hydroprocessing catalyst grading process according to claim 1, wherein the hydrodemetallization catalyst is supported on an inorganic oxide, and the active component of the hydrodemetallization catalyst comprises a group VIB metal and/or a group VIII metal in addition to Mo.

8. The hydroprocessing catalyst grading process according to claim 7, wherein the hydrodemetallization catalyst further comprises a promoter selected from at least one of P, Si, F, B.

9. The hydroprocessing catalyst grading method according to claim 1, wherein the hydrodesulfurization catalyst comprises an inorganic oxide as a carrier, and the active component of the hydrodesulfurization catalyst comprises a group VIB metal and/or a group VIII metal in addition to Mo.

10. The hydroprocessing catalyst grading method according to claim 9, wherein the hydrodesulfurization catalyst further comprises a promoter selected from at least one of P, Si, F, B.

11. The hydroprocessing catalyst grading process according to any one of claims 7 to 10, characterized in that the inorganic oxide is selected from at least one of alumina and silica, the group VIB metal is W; the group VIII metal is selected from at least one of Co and Ni.

12. The hydroprocessing catalyst staging method according to claim 1, wherein the conditions for hydroprocessing the heavy oil are: hydrogen pressure of 5.0 MPa-20.0 MPa, temperature of 300-450 deg.c and liquid hourly space velocity of 0.2 hr^-1～5^-1The volume ratio of hydrogen to oil is 300-2500.

13. The hydroprocessing catalyst grading process according to claim 12, characterized in thatThe conditions for the hydrotreatment of the heavy oil are as follows: hydrogen pressure of 8.0MPa to 18.0MPa, temperature of 330 ℃ to 440 ℃, liquid hourly volume space velocity of 0.2h^-1～3h^-1The volume ratio of hydrogen to oil is 400-2000.

14. The hydroprocessing catalyst staging method according to claim 13, wherein the conditions for hydroprocessing of the heavy oil are: hydrogen pressure of 10.0MPa to 16.0MPa, temperature of 350 ℃ to 430 ℃, liquid hourly volume space velocity of 0.2h^-1 ～ 2h^-1The volume ratio of hydrogen to oil is 500-1500.