CN116060032A

CN116060032A - Wax oil hydrotreating catalyst and preparation method and application thereof

Info

Publication number: CN116060032A
Application number: CN202111277854.0A
Authority: CN
Inventors: 徐黎明; 高玉兰; 佟佳; 杨占林; 杨涛
Original assignee: China Petroleum and Chemical Corp; Sinopec Dalian Research Institute of Petroleum and Petrochemicals
Current assignee: Sinopec Dalian Petrochemical Research Institute Co ltd; China Petroleum and Chemical Corp
Priority date: 2021-10-30
Filing date: 2021-10-30
Publication date: 2023-05-05

Abstract

The invention discloses a wax oil hydrotreating catalyst and a preparation method and application thereof. The preparation method comprises the steps of firstly preparing an intermediate from alumina powder and a sulfide precursor solution containing VIB metal, and then preparing a wet filter cake from the intermediate and alumina sol; further mixing with a compound containing a metal of the VIII family and an extrusion aid, forming, drying and roasting to obtain a catalyst precursor; finally, introducing VIB and/or VIII metal and vulcanizing agent, drying and roasting to obtain the catalyst. The hydrotreating catalyst prepared by the method disclosed by the invention contains an I-type active phase and a high-activity II-type active phase which are suitable for moderating hydrogenation, and has the advantages of high active metal utilization rate, simple preparation method, good economy and the like.

Description

Wax oil hydrotreating catalyst and preparation method and application thereof

Technical Field

The invention belongs to the technical field of catalytic materials, and particularly relates to a hydrogenation catalytic material and a preparation method and application thereof, in particular to a wax oil hydrogenation catalyst and a preparation method thereof.

Background

Wax oil hydroprocessing technology began to be applied in the seventies of the last century, with the primary objective of meeting environmental regulations for the production of low sulfur fuel oils and for the reduction of FCC unit regenerator sulfide emissions. Currently, about 40% of the feed to fcc units worldwide employs a hydrotreating process. In recent years, it has been recognized that reducing the nitrogen and aromatic content of FCC feed increases the plant gasoline yield and increases the benefits, which are also new requirements for FCC feedstock hydroprocessing processes. With the advent of the petroleum age after the world, crude oil deep processing and clean fuel production technologies will further develop rapidly. The development of FCC technology is to increase the conversion capability of heavy oil, reduce the contents of sulfur, nitrogen, olefin and the like in the products and increase the yield of the target products, thereby creating higher benefits, and the deep hydrotreating of FCC raw materials is one of the effective means for achieving the above purposes, which is accepted and accepted in the oil refining industry.

CN00110019.X relates to a hydrogenation activity protective agent and a preparation method thereof, wherein a carrier used by the protective agent contains gamma-alumina and delta-alumina at the same time; the protective agent contains 3-22m% of VIB group metal oxide, 0.5-5m% of VIII group metal oxide, 0-2 m% of IA group metal oxide, 0-3 m% of phosphorus and 100-250 m of specific surface ² Per gram, the pore volume is 0.4-0.8 ml/g. Is especially suitable for serving as a protective agent of heavy raw oil with low quality, high sulfur, high nitrogen and high metal content. Can effectively solve the problems of forced shutdown caused by scaling, blockage and overlarge pressure drop of the catalyst bed of the industrial hydrogenation device, and prolong the service life of the hydrogenation catalyst.

CN1205314C discloses a preparation method of wax oil hydrodemetallization and desulfurization catalyst, the carrier alumina adopts two kinds of composites, one of which is alumina powder baked at high temperature of 1100 ℃, the method can form more pore channels with the diameter of more than 15nm, the pore channels have penetrability, which is favorable for the diffusion and reaction of raw materials, but carbon deposition cannot be inhibited, and the service life of the catalyst is not obviously improved.

CN200910236167.7 relates to a method for hydrotreating inferior wax oil, which comprises the steps of reacting at 360-380 ℃ and 8-10.0 MPa, hydrogen-oil volume ratio of 1000-1500:1 and liquid hourly space velocity of 0.5-1.0 h ^-1 Hydrotreating a mixture feed of vacuum gas oil, poor coker gas oil and deasphalted oil under conditions; the catalyst is a graded catalyst, and is sequentially graded and filled with a protective agent, a demetallizing agent, a desulfurizing agent and a denitrifying agent from top to bottom; the catalyst has the advantages of low reaction temperature, low reaction pressure and high activity, and the raw material can be directly used as FCC raw material or hydrocracking raw material after being hydrotreated.

Disclosure of Invention

Aiming at the defects existing in the prior art, the invention provides a wax oil hydrotreating catalyst, a preparation method and application thereof, and the prepared hydrotreating catalyst simultaneously contains a I-type active phase suitable for moderating hydrogenation and a high-activity II-type active phase and has the advantages of high active metal utilization rate, simple preparation method, good economy and the like.

In order to achieve the above object, the present invention firstly provides a wax oil hydrotreating catalyst, which comprises a carrier and an active component, wherein the carrier is alumina, and the active component is at least one of group VIB metal and/or group VIII metal.

Further, in the wax oil hydrotreating catalyst, the wax oil hydrotreating catalyst contains a class I active phase and a class II active phase at the same time, and the ratio of the class I active phase to the class II active phase is 1:1-1:6, preferably 1:2-1:4.

Further, in the wax oil hydrotreating catalyst, the catalyst has a double-peak pore canal, wherein the pore diameter of the small pore is 3-8 nm, and the pore diameter of the large pore is 8-20 nm; wherein the pore volume of the pores with the diameter of 3-8 nm accounts for 50-80% of the total pore volume, and is preferably 55-75%; the pore volume of the pores with the diameter of 8-20 nm accounts for 10-40% of the total pore volume, and is preferably 15-35%.

Further, in the wax oil hydrotreating catalyst, the total pore volume of the catalyst is 0.3-0.8 mL/g.

Further, in the wax oil hydrotreating catalyst, the specific surface area of the catalyst is 120-350 m ² /g。

Further, in the wax oil hydrotreating catalyst, the carrier content is 65-85 wt% and the active component content is 15-35 wt% based on the weight of the catalyst.

In another aspect, the invention provides a method for preparing a wax oil hydrotreating catalyst, comprising the following steps:

(1) Roasting pseudo-boehmite to obtain alumina powder;

(2) Mixing the alumina powder obtained in the step (1) with a sulfide precursor solution containing VIB group metal, and obtaining an intermediate after impregnation and separation;

(3) Adding the intermediate obtained in the step (2) into alumina sol, uniformly mixing, and performing suction filtration to obtain a wet filter cake;

(4) Mixing the wet filter cake obtained in the step (3), a compound containing VIII family metal and an extrusion aid, molding, drying and roasting to obtain a catalyst precursor;

(5) Introducing VIB and/or VIII metal and vulcanizing agent into the catalyst precursor, and drying and roasting to obtain the catalyst.

Further, in the preparation method of the wax oil hydrotreating catalyst, the roasting temperature in the step (1) is 400-770 ℃, preferably 500-700 ℃; the calcination is performed under an air atmosphere.

Further, in the preparation method of the wax oil hydrotreating catalyst, the dry basis content of pseudo-boehmite in the step (1) is 60-80 wt%, preferably 65-75 wt%; sodium oxide content less than 0.1wt%, preferably less than 0.05wt%; the pore volume is generally 0.6-0.9 mL/g. The pseudo-boehmite can be self-made or prepared according to the method disclosed by the prior art, and can also be purchased for commercial goods.

In the preparation method of the wax oil hydrotreating catalyst, the sulfide precursor containing VIB group metal is a sulfide precursor containing Mo and/or W, and can be thiomolybdate and/or thiotungstate, and further preferably is ammonium salt. The thiomolybdate can be any one or more of tetrathiomolybdate and hydrocarbyl thiomolybdate; the thiotungstate can be any one or more of tetrathiotungstate and hydrocarbyl thiotungstate; the number of carbon atoms in the hydrocarbyl group of the hydrocarbyl thiomolybdate or the hydrocarbyl thiotungstate is generally 1 to 100, preferably 2 to 20. May be a saturated hydrocarbon group such as an alkyl group, a cycloalkyl group, etc., or may be an unsaturated hydrocarbon group such as an olefin, etc.

Further, in the preparation method of the wax oil hydrotreating catalyst, any one of supersaturated impregnation, saturated impregnation and unsaturated impregnation can be adopted for impregnation.

Furthermore, in the preparation method of the wax oil hydrotreating catalyst, the separation in the step (2) can be any one of the liquid-solid two-phase separation means in the prior art, such as filtration, centrifugal separation and the like, and the separation can be selected by a person skilled in the art according to actual needs.

Further, in the preparation method of the wax oil hydrotreating catalyst, the pore volume of the alumina sol is more than 1.0mL/g, and the preferable pore volume is 1.0-1.2 mL/g; the peptization of the alumina sol is more than 90%; the alumina sol can be self-made or prepared according to the existing method, and can also be commercially available.

Furthermore, in the preparation method of the wax oil hydrotreating catalyst, the alumina sol can be prepared by the following method: mixing an organic aluminum compound with deionized water, then carrying out hydrolysis, and adding an acidic substance to regulate and control the hydrolysis speed to obtain the required alumina sol; wherein the organic aluminum compound is one or more of aluminum alkyl and aluminum alkoxy, the aluminum alkyl is at least one of trimethylaluminum, triethylaluminum, tripropylaluminum, triisobutylaluminum and the like, the carbon number of the aluminum alkoxy is 3-20, the organic aluminum compound can be at least one of aluminum triethoxide, aluminum tripropanol, aluminum triisopropoxide, aluminum tri-n-butoxide and the like, the hydrolysis temperature is 40-120 ℃, and the acidic substance can be one or more of nitric acid, hydrochloric acid, perchloric acid, oxalic acid and the like.

In the preparation method of the wax oil hydrotreating catalyst, the compound containing the VIII group metal is inorganic salt or complex of the VIII group metal, the VIII group metal is Ni and/or Co, and the compound containing the VIII group metal can be one or more of nickel nitrate, basic nickel carbonate, nickel citrate, cobalt nitrate, basic cobalt carbonate and cobalt citrate.

Furthermore, in the preparation method of the wax oil hydrotreating catalyst, the extrusion aid can be one or more of sesbania powder, starch, methylcellulose, polyvinyl alcohol and polyethylene alcohol, and the dosage of the extrusion aid is 1.0-5.0 wt% of the weight of the catalyst. Extrusion aids are well known to those skilled in the art, and the particular type of material employed and the amount added can be determined as known in the art.

Further, in the above-mentioned wax oil hydrotreating catalyst preparation method, the amount and ratio of the group viii metal-containing solution to Mo and/or W in step (1) are well known to those skilled in the art, and can be specifically determined according to the needs of the catalyst to be produced, and generally ranges from 5% to 50% by weight of the oxide.

Further, in the preparation method of the wax oil hydrotreating catalyst, the drying temperature in the step (4) is 20-200 ℃, preferably 60-160 ℃, and the time is 1-24 hours, preferably 3-12 hours. The drying is performed in the presence of hydrogen and/or an inert atmosphere, which may be at least one of nitrogen, helium, neon, argon, and the like.

Further, in the above preparation method of wax oil hydrotreating catalyst, the roasting temperature in step (4) is 300-500 ℃, preferably 350-450 ℃, and the roasting time is 1-24 hours, preferably 3-12 hours. The roasting is performed in the presence of hydrogen and/or an inert atmosphere, and the inert atmosphere can be at least one of nitrogen, helium, neon, argon and the like.

Further, in the preparation method of the wax oil hydrotreating catalyst, in the step (5), VIB group and/or VIII group metals are introduced into the catalyst precursor in a dipping mode; the catalyst precursor is mixed with an inorganic salt solution containing VIB and/or VIII metal for impregnation, and the specific proportion and the dosage are regulated and controlled by the person skilled in the art according to the product requirement. In the invention, the weight ratio of the metal element of VIB group contained in the step (2) to the metal element of VIB group in the step (4) is 1:1-6:1, and the weight ratio of the metal of VIII group to the metal of VIB group is 1:4-1:8.

Further, in the above preparation method of wax oil hydrotreating catalyst, the drying temperature in step (5) is 20 to 200 ℃, preferably 60 to 160 ℃, and the time is 1 to 24 hours, preferably 3 to 12 hours. The drying is performed in the presence of an inert atmosphere, which may be at least one of nitrogen, helium, neon, argon, and the like.

Further, in the preparation method of the wax oil hydrotreating catalyst, the roasting temperature in the step (5) is 400-700 ℃, preferably 450-600 ℃, and the roasting time is 1-24 hours, preferably 3-12 hours. The calcination is performed in the presence of an inert atmosphere, which may be at least one of nitrogen, helium, neon, argon, and the like.

In the preparation method of the wax oil hydrotreating catalyst, the vulcanizing agent in the step (5) may be at least one of carbon disulfide, mercaptan, sulfoxide, dimethyl disulfide, thiophene and the like, and the dosage of the vulcanizing agent is generally 3-25% of the mass of the catalyst.

The third aspect of the invention provides a wax oil hydrogenation method, wherein a wax oil raw material and hydrogen are reacted in a reactor, and the reactor is filled with the wax oil hydrogenation catalyst.

Further, in the wax oil hydrogenation method, the wax oil is one or more of vacuum wax oil, coker wax oil and vacuum gas oil.

Further, in the wax oil hydrogenation method, the reaction conditions are generally as follows: the reaction temperature is 350-380 ℃, the reaction pressure is 6.0-15.0 MPa, and the hydrogen-oil volume ratio is 300-1500: 1, the volume airspeed is 0.5 to 2h ^-1 。

Compared with the prior art, the wax oil hydrotreating catalyst provided by the invention and the preparation method and application thereof have the following advantages:

1. in the preparation method of wax oil hydrotreating catalyst of the invention, sulfide precursor solution and alumina powder and VIII group metal (Ni and/or Co) are extruded and formedIn the subsequent heat treatment process, the sulfide precursor is decomposed on the surface of the alumina to form tiny and uniformly distributed MoS with low valence state ₂ And WS (WS) ₂ More corner edges are formed, which is beneficial to the adsorption of VIII group metal (Ni and/or Co) and forms a type II Ni (Co) Mo (W) S active phase with higher activity with Mo and/or W. The method avoids the generation temperature of the metal sulfide being lower than that of alumina when the pseudo-boehmite and the metal sulfide precursor are baked after being molded, damages the microstructure of the carrier and the active metal, and is unfavorable for forming a high-activity active phase.

2. According to the preparation method of the wax oil hydrotreating catalyst, the baked alumina powder and alumina sol are mixed and extruded to form a strip, the formed intermediate takes alumina containing a class II active phase as a core, colloidal particles of the alumina sol are wrapped and bonded on the surface, the intermediate with moderate strength can be obtained, in the subsequent impregnation of metal inorganic salt, a class VIB active metal component preferentially occupies the surface of alumina on the outer layer, and a class I active phase with stronger acting force is formed with the alumina after drying and baking, so that the wax oil component is preferentially adsorbed on the surface of the class I active phase in the reaction, the hydrogenation is alleviated, and then the deep hydrogenation is further carried out on the class II active center with high activity. The hydrogenation depth of wax oil can be improved, carbon deposition can be reduced, and the deactivation speed of the catalyst can be reduced.

3. In the preparation method of the wax oil hydrotreating catalyst, the finished catalyst is a fully vulcanized catalyst, raw oil can be directly produced normally without vulcanization during use, environmental pollution and equipment corrosion caused by vulcanizing agents are avoided, the startup time is saved, and the utilization rate of the equipment is improved.

4. In the preparation method of the wax oil hydrotreating catalyst, no peptizing agent is used, so that the damage of the peptizing agent to the pseudo-boehmite pore structure is avoided, the original pore structure of the dry gel powder is maintained, the increase of pores formed secondarily is avoided, and the pore volume and the specific surface area of the hydrotreating catalyst are larger.

Detailed Description

The technical features of the present invention are further described below by way of examples, which are not intended to limit the present invention.

In the method, the I-type active phase has strong acting force on the carrier, the stacking layer number of the active metal is 1-2, the active metal is not easy to vulcanize, the hydrogenation activity is low, and the method is suitable for moderating hydrogenation. The acting force of the II-type active phase and the carrier is weak, metal is easy to vulcanize, high-activity active phase is easy to form, the active phase is distributed on the surface of the carrier in multiple layers, the active center is the corner edge position of the metal lamination, the stacking layer number of the active metal is 3-8, the hydrogenation activity is high, and components which are difficult to convert can be hydrogenated.

In the technical field, the active phase is tested and analyzed by a Transmission Electron Microscope (TEM) to obtain the microscopic morphology of the active metal phase. 20 TEM pictures randomly selected from each sample are counted by Digital Micrograph software, the average stacking layer number and the average sheet length of the molybdenum disulfide/tungsten wafers in the pictures are classified into I-type active phases, the stacking layer number is 1-2, the stacking layer number is 3-8, and the stacking layer number is classified into II-type active phases, so that the distribution condition of the I-type active phases and the II-type active phases on the carrier surface is calculated.

In the context of the present specification, the method of measuring the dry basis content comprises: weighing 10g of pseudo-boehmite raw material, placing the pseudo-boehmite raw material into a muffle furnace for high-temperature roasting, keeping the roasting condition at 600 ℃ for 3 hours, taking out and weighing the weight of a later sample, dividing the weight of the later sample by 10g, and multiplying the weight by 100%, thus obtaining the dry basis content of the sample.

In the context of the present specification, pore volume and specific surface area are analyzed using a low temperature nitrogen adsorption method.

Herein, the peptization method of alumina sol is as follows: 10g of pseudo-boehmite is added into water to form a solution with the concentration of 10wt%, concentrated sulfuric acid Mg is added, M=1.6 (pseudo-boehmite dry basis content), the solution is stirred for 0.5h and centrifuged, clear solution is taken, dried at 120 ℃ and roasted at 600 ℃ and then weighed into Ng, the peptization= [ N/(10 x pseudo-boehmite dry basis content) ] is 100%, and the peptization of alumina sol used in the solution is more than 90%.

Example 1

Pseudo-boehmite (pore volume 0.70mL/g, dry basis content 75 wt%) was calcined in a roaster at 600℃for 3 hours to obtain alumina powder. An ammonium thiomolybdate solution (molybdenum oxide concentration: 20g/100 mL) was prepared, alumina powder was immersed in the solution for 1 hour, and the resulting solid was designated as an intermediate.

Taking alumina sol with the pH value of 6 and the solid content of 50wt percent (pore volume of 1.0mL/g and colloid solubility of 92.1 percent), then mixing the intermediate with the alumina sol, leading the alumina provided by the alumina sol in the final product to account for 15wt percent of the mass of the catalyst, and carrying out suction filtration after uniform mixing to obtain a wet filter cake.

Mixing the wet filter cake with nickel nitrate solution (containing 16g/100mL of nickel oxide) and sesbania powder, kneading and extruding the mixture, drying the mixture for 5 hours at 150 ℃ under nitrogen, and roasting the mixture for 3 hours at 350 ℃ to obtain the catalyst precursor.

The catalyst precursor is saturated and impregnated with a sulfoxide solution of molybdenum, nickel and phosphorus (molybdenum oxide 10g/100mL, nickel oxide 2g/100mL, phosphorus 1g/100mL, S4g/100 mL), and the catalyst precursor is dried at 130 ℃ for 6 hours under nitrogen, and baked at 550 ℃ for 3 hours, so that the final finished catalyst is obtained, and the catalyst composition and properties are shown in tables 1 and 2.

Example 2

Taking alumina sol (pore volume 1.2 mL/g) with pH value of 7 and solid content of 40wt%, mixing the intermediate prepared in the embodiment 1 with alumina sol (pore volume 1.1mL/g and gel solubility of 90.4%), making alumina provided by alumina sol in the final catalyst product account for 22wt% of the catalyst mass, mixing uniformly, and suction filtering to obtain a wet filter cake.

Mixing the wet filter cake with nickel nitrate solution (containing nickel oxide 12g/100 mL) and sesbania powder, kneading and extruding the mixture, drying the mixture for 3 hours at 180 ℃ under nitrogen, and roasting the mixture for 3 hours at 380 ℃ to obtain the catalyst precursor.

The catalyst precursor was impregnated with a molybdenum cobalt sulfoxide solution (molybdenum oxide 18g/100mL, cobalt oxide 2.4g/100mL, S5g/100 mL), dried at 150℃for 5 hours under nitrogen, and calcined at 500℃for 3 hours to give the final catalyst finished product, the catalyst composition and properties are shown in tables 1 and 2.

Example 3

Pseudo-boehmite (pore volume 0.68mL/g, dry basis content 73 wt%) was calcined in a roaster at 650℃for 3 hours to obtain alumina powder. Ammonium thiomolybdate and ammonium thiotungstate solutions (molybdenum oxide concentration was 12g/100mL, tungsten oxide concentration was 8g/100 mL) were prepared, alumina powder was immersed in the solutions for 1h, and the obtained solid was denoted as an intermediate by centrifugal separation.

Taking alumina sol with the pH value of 5 and the solid content of 55wt percent (pore volume of 1.1mL/g and colloid solubility of 93.4 percent), mixing the intermediate with the alumina sol, leading the alumina provided by the alumina sol in the final product to account for 18wt percent of the mass of the catalyst, and carrying out suction filtration after uniformly mixing to obtain a wet filter cake.

Mixing the wet filter cake with nickel nitrate solution (containing 16g/100mL of nickel oxide) and sesbania powder, kneading and extruding the mixture, drying the mixture for 5 hours at 200 ℃ under nitrogen, and roasting the mixture for 3 hours at 400 ℃ to obtain the catalyst precursor.

The catalyst precursor was impregnated with a molybdenum cobalt solution (molybdenum oxide 12g/100mL, cobalt oxide 2g/100 mL), dried at 170℃for 5 hours under nitrogen, then saturated spray-impregnated with DMDS, dried at 110℃for 3 hours under nitrogen, and calcined at 520℃for 3 hours to give the final finished catalyst, the catalyst composition and properties are shown in tables 1 and 2.

Example 4

Pseudo-boehmite (pore volume 0.68mL/g, dry basis content 73 wt%) was calcined in a roaster at 650℃for 3 hours to obtain alumina powder. An ammonium thiomolybdate solution (molybdenum oxide concentration: 22g/100 mL) was prepared, and alumina powder was spray-immersed in the solution, and the resulting solid was designated as an intermediate.

Taking alumina sol with the pH value of 6.2 and the solid content of 43wt percent (pore volume of 1.2mL/g and colloid solubility of 91.6 percent), mixing the intermediate with the alumina sol, leading the alumina provided by the alumina sol in the final product to account for 20wt percent of the mass of the catalyst, and carrying out suction filtration after uniformly mixing to obtain a wet filter cake.

Mixing the wet filter cake with nickel nitrate solution (containing nickel oxide 20g/100 mL) and sesbania powder, kneading and extruding the mixture, drying the mixture at 120 ℃ for 8 hours under nitrogen, and roasting the mixture at 420 ℃ for 3 hours to obtain the catalyst precursor.

The catalyst precursor was impregnated with a tungsten cobalt solution (12 g/100mL of tungsten oxide, 3.5g/100mL of cobalt oxide), dried at 170℃for 5 hours under nitrogen, and calcined at 480℃for 3 hours to give the final catalyst finished product, the catalyst composition and properties are shown in tables 1 and 2.

Example 5

Pseudo-boehmite (pore volume 0.75mL/g, dry basis content 77 wt%) was calcined in a roaster at 650℃for 2 hours to obtain alumina powder. An ammonium thiomolybdate solution (molybdenum oxide concentration: 25g/100 mL) was prepared, and alumina powder was spray-immersed in the solution, and the resulting solid was designated as an intermediate.

Taking alumina sol with the pH value of 7 and the solid content of 42wt percent (pore volume of 1.3mL/g and colloid solubility of 93.5 percent), then mixing the intermediate with the alumina sol, leading the alumina provided by the alumina sol in the final product to account for 21wt percent of the catalyst mass, and carrying out suction filtration after uniform mixing to obtain a wet filter cake.

Mixing the wet filter cake with nickel nitrate solution (containing nickel oxide 20g/100 mL) and sesbania powder, kneading and extruding the mixture, drying the mixture for 3 hours at 160 ℃ under nitrogen, and roasting the mixture for 3 hours at 420 ℃ to obtain the catalyst precursor.

The catalyst precursor was saturated impregnated with molybdenum nickel ammonia solution (molybdenum oxide 14g/100mL, nickel oxide 4g/100 mL), dried at 100deg.C under nitrogen for 6 hours, and calcined at 580 deg.C for 3 hours to obtain the final catalyst product, the catalyst composition and properties are shown in tables 1 and 2.

Comparative example 1

91g of pseudo-boehmite (pore volume of 0.70mL/g, dry basis content of 70 wt%) 91g of macroporous pseudo-boehmite (pore volume of 1.2mL/g, dry basis content of 72 wt%) 22g, 26g of SB powder and ammonium thiomolybdate solution (molybdenum oxide concentration of 35g/100 mL), nickel nitrate solution (containing 16g/100mL of nickel oxide), 3g of sesbania powder and 2g of dilute nitric acid are kneaded and extruded, dried for 5 hours at 150 ℃ under nitrogen, and baked for 3 hours at 600 to obtain the final finished catalyst.

Comparative example 2

91g of pseudo-boehmite (pore volume of 0.70mL/g, dry basis content of 70 wt%) 91g of macroporous pseudo-boehmite (pore volume of 1.2mL/g, dry basis content of 72 wt%) 22g, 26g of SB powder, molybdenum nickel phosphorus solution (molybdenum oxide of 32g/100mL, nickel oxide of 6g/100mL and phosphorus of 1.5g/100 mL), 3g of sesbania powder and 2g of dilute nitric acid are kneaded and extruded, dried for 5 hours at 150 ℃ and baked for 3 hours at 600 ℃ to obtain the final finished catalyst.

Comparative example 3

66g of pseudo-boehmite (pore volume of 0.75mL/g, dry basis content of 77 wt%) and 29g of macroporous pseudo-boehmite (pore volume of 1.2mL/g, dry basis content of 72 wt%) are mixed and extruded, extruded and extruded, and dried for 3 hours at 180 ℃, and the finished catalyst is obtained by roasting tungsten-molybdenum-nickel cobalt solution (tungsten oxide 15 g/100mL, molybdenum oxide 32g/100mL, nickel oxide 4.5g/100mL, cobalt oxide 3.5g/100 mL), sesbania powder 5g and dilute nitric acid 3.5g at 550 ℃ for 3 hours.

Evaluation test

Catalyst activity evaluation methods prepared in examples 1 to 5 and comparative example 1:

and (3) filling the catalyst into a reactor, heating to 120 ℃ at a speed of 20 ℃/h, feeding straight-run diesel oil, continuously heating to 370 ℃, changing raw oil, keeping constant after keeping constant temperature for 4 hours, sampling and analyzing every 8 hours, evaluating 1000 hours for shutdown, and taking out the catalyst for sulfur-carbon analysis. Raw oil properties: density 910kg/m ³ 6.1% of polycyclic aromatic hydrocarbon, 1.28% of sulfur and 0.24% of nitrogen, and the technological conditions are as follows: the reaction temperature is 378 ℃, the reaction pressure is 14.7MPa, and the space velocity is 1.0h ^-1 The evaluation results are shown in Table 1.

Comparative example 2 evaluation method of catalyst activity prepared:

loading the catalyst into a reactor, heating to 150 ℃ at a speed of 20 ℃/h, feeding working oil (kerosene containing 2wt% of carbon disulfide), continuously heating to 230 ℃, keeping the temperature for 4 hours, heating to 320 ℃, keeping the temperature for 8 hours, changing the raw oil, continuously heating to 370 ℃, keeping the temperature for 4 hours, starting constant, sampling and analyzing every 8 hours, evaluating 1000 hours for shutdown, and taking out the catalyst for sulfur-carbon analysis. Raw oil properties: density 910kg/m ³ 6.1% of polycyclic aromatic hydrocarbon, 1.28% of sulfur and 0.24% of nitrogen, and the technological conditions are as follows: the reaction temperature is 378 ℃, the reaction pressure is 14.7MPa, and the space velocity is 1.0h ^-1 The evaluation results are shown in Table 1.

TEM analysis was performed on sulfided catalyst and sulfided oxidized catalyst samples, 20 TEM pictures were randomly selected for each sample, the average number of stacked layers and average platelet length of the molybdenum disulfide wafers in these pictures were counted by Digital Micrograph software, the number of stacked layers was 1-2 and classified as a type I active phase, the number of stacked layers was 3-8 and classified as a type II active phase, and the results are shown in Table 2.

TABLE 1 physicochemical Properties of the catalyst and evaluation results

TABLE 2 results of distribution of the catalyst surface active phases

From tables 1 and 2, it can be seen that the sulfide precursor is directly supported on the alumina powder, so that the influence of the alumina crystal form transformation on the metal active phase is avoided, the active phase with high activity is easy to form, and the activity of the catalyst is further improved. Compared with the oxidation state catalyst prepared by the kneading method, the sulfidation catalyst prepared by the method has the active phase of an organic combination of I and II, and can have the mild hydrogenation activity and the deep hydrogenation activity of the catalyst.

Claims

1. A wax oil hydrotreating catalyst comprises a carrier and an active component, wherein the carrier is alumina, and the active component is at least one of VIB metal and/or VIII metal; the wax oil hydrotreating catalyst contains a class I active phase and a class II active phase at the same time, and the ratio of the class I active phase to the class II active phase is 1:1-1:6, preferably 1:2-1:4.

2. The wax oil hydrotreating catalyst according to claim 1, wherein the catalyst has a bimodal pore path in which the pore diameter of small pores is 3 to 8nm and the pore diameter of large pores is 8 to 20nm; wherein the pore volume of the pores with the diameter of 3-8 nm accounts for 50-80% of the total pore volume, and is preferably 55-75%; the pore volume of the pores with the diameter of 8-20 nm accounts for 10-40% of the total pore volume, and is preferably 15-35%.

3. The wax oil hydrotreating catalyst as claimed in claim 1, wherein the total pore volume of the catalyst is 0.3 to 0.8.

4. Wax oil hydroprocessing catalyst according to claim 1, wherein the catalyst ratioSurface area of 120-350 m ² /g。

5. A preparation method of a wax oil hydrotreating catalyst comprises the following steps:

(1) Roasting pseudo-boehmite to obtain alumina powder;

6. The process for preparing a wax oil hydrotreating catalyst in accordance with claim 5, wherein the calcination temperature in step (1) is 400 ℃ to 770 ℃, preferably 500 ℃ to 700 ℃.

7. The method for preparing a wax oil hydrotreating catalyst according to claim 5, wherein the dry basis content of pseudo-boehmite in the step (1) is 60wt% to 80wt%, preferably 65wt% to 75wt%; sodium oxide content less than 0.1wt%, preferably less than 0.05wt%; the pore volume is 0.6-0.9 mL/g.

8. The method for preparing a wax oil hydrotreating catalyst in accordance with claim 5, wherein the group VIB metal sulfide-containing precursor is a Mo and/or W sulfide-containing precursor.

9. The method for preparing a wax oil hydrotreating catalyst according to claim 5, wherein the group VIB metal sulfide-containing precursor is thiomolybdate and/or thiotungstate, and more preferably ammonium salt.

10. The method for preparing a wax oil hydrotreating catalyst according to claim 9, wherein the thiomolybdate is any one or more of tetrathiomolybdate and hydrocarbylthiomolybdate; the thiotungstate is any one or more of tetrathiotungstate and alkyl thiotungstate; the number of carbon atoms of the hydrocarbyl group in the hydrocarbyl thiomolybdate or hydrocarbyl thiotungstate is 1 to 100, preferably 2 to 20.

11. The method for preparing a wax oil hydrotreating catalyst according to claim 5, wherein the alumina sol has a pore volume of more than 1.0mL/g, preferably a pore volume of 1.0 to 1.2mL/g; the peptization of the alumina sol is greater than 90%.

12. The process for preparing a catalyst for hydrotreating a wax oil in accordance with claim 5, wherein the group VIII metal-containing compound is a group VIII metal inorganic salt or a group VIII metal complex, and the group VIII metal is Ni and/or Co.

13. The method for preparing a wax oil hydrotreating catalyst as claimed in claim 5, wherein the group VIII metal-containing compound is one or more of nickel nitrate, basic nickel carbonate, nickel citrate, cobalt nitrate, basic cobalt carbonate and cobalt citrate.

14. The method for preparing a wax oil hydrotreating catalyst according to claim 5, wherein the extrusion aid is one or more of sesbania powder, starch, methylcellulose, polyvinyl alcohol and polyethanol, and the dosage of the extrusion aid is 1.0-5.0 wt% of the weight of the catalyst.

15. The process for preparing a wax oil hydrotreating catalyst as claimed in claim 5, wherein the drying in step (4) is carried out at a temperature of 20 to 200 ℃, preferably 60 to 160 ℃, in the presence of hydrogen and/or an inert atmosphere.

16. The process for preparing a wax oil hydrotreating catalyst in accordance with claim 5, wherein the calcination in step (4) is carried out at a temperature of 300 to 500 ℃, preferably 350 to 450 ℃, in the presence of hydrogen and/or an inert atmosphere.

17. The method for preparing a wax oil hydrotreating catalyst according to claim 5, wherein the weight ratio of the group VIB metal element contained in the step (2) to the group VIB metal element contained in the step (4) is 1:1 to 6:1, and the weight ratio of the group VIII metal to the group VIB metal is 1:4 to 1:8.

18. The process for preparing a wax oil hydrotreating catalyst in accordance with claim 5, wherein the drying in step (5) is carried out at a temperature of 20 to 200 ℃, preferably 60 to 160 ℃, in the presence of an inert atmosphere.

19. The process for preparing a wax oil hydrotreating catalyst in accordance with claim 5, wherein the calcination in step (5) is carried out in the presence of an inert atmosphere at a calcination temperature of 400 to 700 ℃, preferably 450 to 600 ℃.

20. The method for preparing a wax oil hydrotreating catalyst according to claim 5, wherein the vulcanizing agent in the step (5) is at least one of carbon disulfide, mercaptan, sulfoxide, dimethyl disulfide, thiophene and the like, and the amount of the vulcanizing agent is 3-25% of the mass of the catalyst.

21. A wax oil hydrogenation method comprises the steps of reacting a wax oil raw material with hydrogen in a reactor, wherein the reactor is filled with the wax oil hydrogenation catalyst.

22. The wax oil hydrogenation method according to claim 21, wherein the wax oil is one or more of vacuum wax oil, coker wax oil and vacuum gas oil.

23. The wax oil hydrogenation process according to claim 21, wherein the reaction conditions are: the reaction temperature is 350-380 ℃, and the reaction pressure is6.0-15.0 MPa, hydrogen oil volume ratio is 300-1500: 1, the volume airspeed is 0.5 to 2h ^-1 。