CN110041959B

CN110041959B - Preparation method of hydrocracking catalyst

Info

Publication number: CN110041959B
Application number: CN201810037390.8A
Authority: CN
Inventors: 徐学军; 王海涛; 王继锋; 刘东香; 冯小萍
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: 2018-01-16
Filing date: 2018-01-16
Publication date: 2021-01-05
Anticipated expiration: 2038-01-16
Also published as: CN110041959A

Abstract

The invention discloses a preparation method of a hydrocracking catalyst. The method comprises the steps of firstly carrying out parallel flow reaction on a mixed solution A containing Ni and W, an organic assistant P1 and a sodium metaaluminate alkaline solution, ageing the obtained slurry, carrying out parallel flow reaction on a mixed solution B containing W, Si and Al, an organic assistant P2 and ammonia water, adding the mixed solution B containing W, Si and Al and the ammonia water into the aged slurry for reaction, adding a suspension of a molecular sieve, carrying out ageing, drying, forming and the like to prepare the hydrocracking catalyst. The hydrocracking catalyst is suitable for medium oil type hydrocracking catalysts, and has good activity and selectivity.

Description

Preparation method of hydrocracking catalyst

Technical Field

The invention relates to a preparation method of a hydrocracking catalyst for treating heavy hydrocarbons, in particular to a preparation method of a bulk phase hydrocracking catalyst.

Background

Hydrocracking is carried out under a relatively high pressure, hydrocarbon molecules and hydrogen are subjected to cracking and hydrogenation reactions on the surface of a catalyst to generate a conversion process of lighter molecules, and hydrodesulfurization, denitrification and hydrogenation reactions of unsaturated hydrocarbons also occur. The cracking reaction of the hydrocarbons in the hydrocracking process is carried out on the acidic center of the catalyst, and follows the carbon ion reaction mechanism, and the hydrocarbon isomerization reaction is accompanied with the hydrogenation and cracking reaction.

The hydrocracking catalyst consists of a hydrogenation component and an acid component, the hydrogenation component and the acid component are added according to a certain proportion as required, so that the hydrogenation performance and the cracking performance are balanced, and the hydrocracking catalyst has the function of fully hydrogenating, cracking and isomerizing a hydrocarbon mixture. Therefore, the catalyst required in the distillate oil hydrocracking process should have a strong hydrogenation activity center and a good acid center. The hydrogenation activity is generally provided by metals selected from groups VIB and VIII of the periodic Table of the elements, while the sources of acidity include zeolites and supports such as inorganic oxides.

The cracking activity of the hydrocracking catalyst derives from the acidity of the support component. The acid centers of the hydrocracking catalyst have a strong adsorption effect on nitrogen-containing compounds in the feed, i.e., the nitrogen-containing compounds have poisoning (shielding) effects on the acid centers of the hydrocracking catalyst to different degrees. Therefore, the high-activity hydrocracking catalyst generally has strict limitation on the nitrogen content of the fed material, impurities such as sulfur, nitrogen, oxygen, metals and the like in the raw material are removed through hydrocracking pretreatment, and the nitrogen content of the fed material is generally controlled to be below 10 microgram/g, so that the activity of the hydrocracking catalyst can be fully exerted. Crude oil tends to be heavy and inferior in the world, the sulfur and nitrogen content of the hydrocracking raw oil is high, and meanwhile, the raw material subjected to hydrocracking pretreatment can not meet the requirement of a hydrocracking catalyst on the nitrogen content in the feed at a high airspeed, or the activity stability of the hydrocracking pretreatment catalyst is reduced due to the fact that impurities in the raw material are more, the nitrogen content of the treated raw material can not meet the requirement, and the nitrogen resistance of the hydrocracking catalyst needs to be improved. The hydrocracking catalyst has good nitrogen resistance, can improve the raw material adaptability of the catalyst, and prolongs the operation period of an industrial device.

In general, hydrocracking catalysts may be prepared using methods such as: impregnation, kneading, beating, coprecipitation, etc., and for noble metals, ion exchange, etc. can be used. The impregnation method is to prepare a carrier firstly and then load active metal, the kneading method is to prepare a carrier component firstly and then knead the carrier component and the active metal, and the coprecipitation method is mainly prepared by precipitating an active metal solution, a silicon solution, an aluminum solution and an acid component. Compared with the conventional supported hydrocracking catalyst, the active metal component in the bulk hydrocracking catalyst is not impregnated and supported on a carrier, but oxide of active metal, silicon and aluminum is generated through coprecipitation, and amorphous silica-alumina in the bulk hydrocracking catalyst also provides a certain acidic cracking function and becomes an important component of the acidic component of the bulk hydrocracking catalyst. The metal loading in the bulk hydrocracking catalyst is not limited. The traditional load type hydrocracking catalyst is limited by a carrier pore structure, the load capacity of active metal is generally not more than 30wt%, the number of active centers which can be provided by the load type hydrocracking catalyst is limited, the limit bottleneck of the number of the active centers can not be broken through, the space for greatly improving the hydrogenation activity is limited, and the requirement of a refinery for producing oil products is difficult to meet.

The bulk phase hydrogenation catalyst is usually a VIB group metal element (Mo, W) and a VIII group metal element (Ni), active metal atoms are mutually staggered to provide a reaction space for reactant molecules, and the active metal is exposed on the surface of the catalyst to provide a reaction activity center for the reactant molecules. The supported catalyst is formed by mixing a type of active center with lower activity and a type of active center with higher activity, while the active centers of the bulk catalyst are basically all the type of active centers, and the bulk catalyst greatly improves the catalytic activity of the bulk catalyst mainly by increasing the density of the active centers on the catalyst. Chianelli et al proposed a spoke-edge model to explain the generation of unsupported catalyst active centers, which model models MoS₂/WS₂The active sites at the edges of the outer layers of the grains are called the spoke sites, provide hydrogenation centers and convert MoS₂/WS₂The edge active sites of the inner layers of the grains are called edge sites and provide hydrogenolysis centers. Thus, the hydrogenation and hydrogenolysis activities of the catalyst are closely related to the distribution of active sites.

In the reaction process, reactant molecules only react on the surface of the catalyst close to the reactant molecules, active metal on the surface of the catalyst prepared by the existing coprecipitation method is not uniformly dispersed, and meanwhile, the disordered distribution of different hydrogenation active metals causes no good coordination effect among the active metals, so that high-content metal in the bulk phase catalyst is easy to excessively stack metal particles, the generation of an active phase is reduced, the active metal cannot become a hydrogenation active center, the utilization rate of the active metal of the catalyst is influenced, and the use cost of the catalyst is also improved.

A hydrocracking catalyst disclosed in US 3954671, a hydroconversion catalyst disclosed in US 4313817, a hydrocracking catalyst of nitrogen tolerant type productive middle distillate disclosed in CN1253988A, a heavy hydrocarbon hydrocracking catalyst disclosed in CN1253989A, and a high-activity, high-medium oil type hydrocracking catalyst disclosed in CN 101239324A. The catalyst is prepared by coprecipitation method, the acidic mixed solution containing active metal reacts with precipitant to prepare precipitate containing active metal, silicon and aluminum, after adding molecular sieve, the finished product catalyst is prepared by drying, shaping and roasting.

CN201611156531.5 discloses a preparation method of a hydrocracking catalyst. The method comprises the steps of carrying out parallel flow coprecipitation on a mixed aqueous solution of a silicon source, an aluminum source and a nickel salt or a salt of the nickel salt and a metal auxiliary agent M (such as Mo, Co and W) and a precipitator to obtain a precipitation slurry, and aging, forming and roasting to obtain the hydrocracking catalyst.

CN103055923A discloses a preparation method of a hydrocracking catalyst. The method adopts an acidic solution containing hydrogenation active metals, an alkaline solution of sodium metaaluminate and gaseous CO₂And adding the mixture into a reaction tank filled with deionized water to form gel, adding suspension of a Y-type molecular sieve, uniformly mixing, filtering, drying, forming, washing, drying and roasting to obtain the hydrocracking catalyst.

CN104588082A discloses a bulk phase hydrocracking catalyst and a preparation method thereof. The method comprises the steps of preparing nickel and aluminum precipitates by a positive addition method, preparing tungsten, silicon and aluminum precipitates by a parallel flow method, mixing the two precipitates, adding Y-type molecular sieve suspension, filtering, forming, roasting and the like to prepare the hydrocracking catalyst.

The above method cannot control the distribution of the hydrogenation active metals well, thereby affecting the distribution of different hydrogenation active metals, being not beneficial to forming effective active phases, being not beneficial to the effective matching of the hydrogenation metals and the acidic components, and finally affecting the performance of the catalyst.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a preparation method of a hydrocracking catalyst. The method can improve the distribution of hydrogenation active metals in the hydrocracking catalyst, promote the formation and the uniform distribution of an effective active phase of the catalyst, simultaneously uniformly distribute acid components in the catalyst, improve the matching effect between the acid components and the active metal components, and finally improve the activity and the selectivity of the catalyst, and is particularly suitable for the medium oil type hydrocracking catalyst.

The inventor finds that a specific active phase in the hydrocracking catalyst can hydrogenate more organic nitrogen-containing compounds with large toxic action on the acid center of the catalyst more quickly, so that the protection effect on the acid center of the catalyst is achieved, the nitrogen resistance of the hydrocracking catalyst is improved, and the property of a hydrocracking product can be improved.

The invention provides a preparation method of a hydrocracking catalyst, which comprises the following steps:

(1) preparing a mixed solution A containing Ni and W, and preparing a mixed solution B containing W, Si and Al;

(2) adding the mixed solution A and an alkaline sodium metaaluminate solution into a reaction tank in a concurrent flow manner to perform a gelling reaction to generate precipitate slurry I containing nickel, tungsten and aluminum, and aging the obtained slurry I;

(3) adding the mixed solution B and ammonia water into the aged slurry I in a concurrent flow manner to perform a gelling reaction to generate a precipitate slurry II containing nickel, tungsten, silicon and aluminum, adding a suspension of a molecular sieve into the slurry II, and then aging under a stirring condition;

(4) after the aging is finished, drying the material obtained in the step (3), forming, washing and drying to obtain a hydrocracking catalyst;

wherein the organic assistant P1 is added in the step (2), and the organic assistant P2 is added in the step (3).

According to the preparation method of the hydrocracking catalyst, the hydrocracking catalyst in the step (4) is vulcanized according to requirements to prepare the vulcanized hydrocracking catalyst.

In the preparation method of the hydrocracking catalyst, the organic auxiliary agent P1 is selected from organic phosphonic acid and/or carboxylic acid polymer. Wherein the organic phosphonic acid can be selected from one or more of ethylenediamine tetramethylene phosphonic acid, hydroxyethylene diphosphonic acid, polyol phosphonate, polyaminopolyether methylene phosphonic acid, 1,2, 4-tricarboxylic acid-2-phosphonic butane, hydroxyphosphonoacetic acid, aminotrimethylene phosphonic acid, diethylenetriamine pentamethylene phosphonic acid, preferably from one or more of ethylenediamine tetramethylene phosphonic acid, hydroxyethylene diphosphonic acid, aminotrimethylene phosphonic acid. The molecular weight of the carboxylic acid polymer is 400-5000, the carboxylic acid polymer is selected from one or more of polyacrylic acid, polymethacrylic acid, polymaleic acid, polyaspartic acid, polyepoxysuccinic acid, acrylic acid-hydroxypropyl acrylate copolymer and maleic acid-acrylic acid copolymer, and preferably one or more of polyacrylic acid, polymethacrylic acid, polymaleic acid, polyaspartic acid and polyepoxysuccinic acid.

In the preparation method of the hydrocracking catalyst, the organic auxiliary agent P2 is selected from organic carboxylic acid with the carbon number of less than 8, and the organic carboxylic acid is one or more of citric acid, tartaric acid, gluconic acid, salicylic acid and malic acid.

In the preparation method of the hydrocracking catalyst, in the step (2), the organic auxiliary agent P1 can be added separately and concurrently, and/or added when the mixed solution A is prepared. The organic auxiliary agent P2 in the step (3) can be added separately and in parallel flow, and/or can be added when preparing the mixed solution B.

Adding an organic assistant P1 in the step (2), wherein the adding amount of the organic assistant P1 is 2-50 g/L, preferably 5-40 g/L based on the volume of the mixed solution A; wherein the organic assistant P2 is added in the step (3), and the adding amount of the organic assistant P2 is 2-40 g/L, preferably 3-30 g/L based on the volume of the mixed solution B.

In the mixed solution A in the step (1), the weight concentration of Ni calculated as NiO is 5-100 g/L, preferably 10-80 g/L, and W calculated as WO₃The weight concentration is 2-60 g/L, preferably 10-50 g/L. In the mixed solution B, W is WO₃The weight concentration is 2-50 g/L, preferably 4-40 g/L, Si is SiO₂The weight concentration is 10-100 g/L, preferably 20-80 g/L, Al is Al₂O₃The weight concentration is 2-60 g/L, preferably 2-50 g/L. When preparing the mixed solution a, the commonly used nickel source may be one or more of nickel sulfate, nickel nitrate and nickel chloride, and the commonly used tungsten source is ammonium metatungstate. When preparing the mixed solution B, the tungsten source generally adopted is ammonium metatungstate; the silicon source can be one or more of silica sol, sodium silicate and water glass; the aluminum source can be one or more of aluminum nitrate, aluminum sulfate, aluminum chloride, aluminum acetate and the like.

In the step (2), W introduced into the catalyst through the mixed solution A accounts for 40-80% of the total W in the catalyst obtained in the step (4) in terms of oxide, and preferably 51-75%. In the step (3), W introduced into the catalyst through the mixed solution B accounts for 20-60% of the weight of W in the catalyst obtained in the step (4) in terms of oxide, and preferably 25-49%.

The concentration of the sodium metaaluminate alkaline solution in the step (2) is Al₂O₃The amount is 15-100 g/L, preferably 20-80 g/L.

The gelling reaction conditions in the step (2) are as follows: the reaction temperature is 20-90 ℃, preferably 30-70 ℃, the pH value is controlled to be 6.0-10.0, preferably 7.0-9.0, and the gelling time is 0.2-2.0 hours, preferably 0.3-1.5 hours. The Al introduced into the catalyst by sodium metaaluminate in the step (2) accounts for 10-75 wt% of the weight of Al in the catalyst obtained in the step (4) calculated by oxide, and preferably 20-70 wt%.

In the step (3), the Si and Al introduced into the catalyst through the mixed solution B account for 20wt% -75 wt%, preferably 25wt% -65 wt%, of the weight of the Si and Al in the catalyst obtained in the step (4), calculated by oxide, wherein the Si accounts for 5wt% -80 wt%, preferably 20wt% -75 wt%, of the total weight of the Si and Al introduced into the catalyst through the mixed solution B, calculated by oxide, calculated by silicon oxide.

The weight concentration of the ammonia water in the step (3) is 5-15%.

In the step (3), the mixed solution B and the precipitant are added into the slurry I obtained in the step (2) in parallel to carry out gelling reaction under the following reaction conditions: the reaction temperature is 20-90 ℃, preferably 30-80 ℃, the pH value is controlled to be 6.0-11.0, preferably 6.5-9.0, and the gelling time is 0.5-4.0 hours, preferably 1.0-3.0 hours.

The aging conditions in step (2) are as follows: the aging temperature is 40-90 ℃, preferably 50-80 ℃, the pH value during aging is controlled to be 6.0-8.0, preferably 6.5-7.5, and the aging time is 0.1-1.0 hour, preferably 0.2-0.8 hour. The aging is carried out under stirring, the preferred stirring conditions being as follows: the stirring speed is 100-300 rpm, preferably 150-250 rpm.

The aging conditions in step (3) are as follows: the aging temperature is 40-90 ℃, preferably 50-80 ℃, the pH value during aging is controlled to be 7.5-11.0, preferably 7.5-9.5, and the aging time is 1.5-6.0 hours, preferably 2.0-5.0 hours. The aging is carried out under stirring, the preferred stirring conditions being as follows: the stirring speed is 300-500 rpm, preferably 300-450 rpm. The pH of the aging of step (3) is at least 0.5 higher, preferably at least 1.0 higher than the pH of the aging of step (2).

The drying, shaping and washing of step (4) may be carried out by methods conventional in the art. Wherein, the drying conditions are as follows: drying for 1-48 hours at 40-120 ℃, wherein the preferable drying conditions are as follows: drying the mixture for 4 to 36 hours at a temperature of between 60 and 110 ℃. In the forming process, conventional forming aids, such as one or more of peptizers, extrusion aids, and the like, can be added as required. The peptizing agent is one or more of hydrochloric acid, nitric acid, sulfuric acid, acetic acid, oxalic acid and the like, the extrusion aid is a substance which is beneficial to extrusion forming, such as one or more of sesbania powder, carbon black, graphite powder, citric acid and the like, and the amount of the extrusion aid accounts for 1-10 wt% of the total dry basis of the materials. The washing is generally carried out by washing with deionized water or a solution containing decomposable salts (such as ammonium acetate, ammonium chloride, ammonium nitrate, etc.) until the solution is neutral.

After the step (4) of molding, the adopted drying conditions are as follows: drying for 1-48 hours at 40-120 ℃, wherein the preferable drying conditions are as follows: drying the mixture for 4 to 36 hours at a temperature of between 60 and 110 ℃.

In the preparation method of the hydrocracking catalyst, the required conventional catalyst auxiliary agent, such as Ti and/or Zr, can be added according to the conventional method. In the preparation of the hydrocracking catalyst of the present invention, it is preferable to add a compound containing an auxiliary component, i.e., a titanium source and/or a zirconium source, during the preparation of the mixed solution a. The titanium source may be one or more of titanium nitrate, titanium sulfate, titanium chloride, etc., and the zirconium source may be one or more of zirconium nitrate, zirconium chloride, zirconium oxychloride, etc. The weight content of the conventional auxiliary components in the hydrocracking catalyst is 20% or less, preferably 15% or less, calculated on an elemental basis.

In the method of the invention, the shape of the catalyst can be sheet, spherical, cylindrical strip and special-shaped strip (clover and clover) according to the requirement, the cylindrical strip and the special-shaped strip (clover and clover) are preferred, the diameter of the catalyst can be 0.8-2.0 mm, and the catalyst can also be thick strip with the diameter of more than 2.5 mm.

In the hydrocracking catalyst of the present invention, the molecular sieve used can adopt all the Y-type molecular sieves which can be used in hydrocracking catalysts in the prior art, such as: y-type molecular sieves disclosed in CN102441411A, CN1508228A, CN101450319A and CN 96119840.0. The Y-type molecular sieve disclosed in CN102441411A is preferred in the invention, the molecular sieve reported in CN 96119840.0 is used as a raw material, hydrothermal treatment deep dealumination is carried out under the conditions that the temperature is 650-800 ℃, the pressure is normal pressure to 0.3MPa, and the time is 20-30 hours, a small amount of ammonia can be contained in water vapor during hydrothermal treatment, the ammonia partial pressure is 50-3000 Pa (absolute pressure), then the acid concentration is 0.5-10.0 mol/L, the time is 0.5-20.0 hours, the temperature is 30-80 ℃, and the ratio of the acid dosage to the weight of the molecular sieve is 1: 1-20: 1, using inorganic acid such as hydrochloric acid, sulfuric acid or nitric acid, and obtaining the Y-type molecular sieve suitable for the invention after hydrothermal treatment and acid treatment, wherein the Y-type molecular sieve has the following properties: the specific surface area is 750-900 m²The crystal cell parameter is 2.423 nm-2.545 nm, the relative crystallinity is 95% -110%, and SiO₂/Al₂O₃The molar ratio is 7-60.

The hydrocracking catalyst obtained in the step (4) of the invention is a bulk phase hydrocracking catalyst containing an organic auxiliary agent, and can be presulfurized by adopting a conventional method before use. The sulfidation is the conversion of the active metals W and Ni into the corresponding sulfides. The vulcanization method can adopt wet vulcanization or dry vulcanization. The sulfurization method adopted in the invention is wet sulfurization, the sulfurization agent is a sulfur-containing substance used in conventional sulfurization, can be an organic sulfur-containing substance, and can also be an inorganic sulfur-containing substance, such as one or more of sulfur, carbon disulfide, dimethyl disulfide and the like, the sulfurized oil is hydrocarbon and/or distillate oil, wherein the hydrocarbon is one or more of cyclohexane, cyclopentane, cycloheptane and the like, and the distillate oil is one or more of kerosene, common first-line diesel oil, common second-line diesel oil and the like. The vulcanizing agent is used in an amount to catalyze hydrocrackingThe vulcanizing degree of each active metal in the agent is not less than 80%, the vulcanizing agent can be adjusted according to the actual situation, and the dosage of the vulcanizing agent can be 80-200%, preferably 100-150% of the theoretical sulfur demand of the complete vulcanization of each active metal in the hydrocracking catalyst. The prevulcanization conditions are as follows: the reactor temperature is 80-120 ℃ when the vulcanized oil is initially fed, the vulcanization reaction temperature is 230-400 ℃, the hydrogen pressure is 5.0-17.0 MPa, and the liquid hourly space velocity is 0.3-4.0 h^-1The vulcanization time is 3-24 h, and the preferable selection is as follows: the initial feeding of the vulcanized oil is 100-120 ℃, the vulcanization reaction temperature is 260-370 ℃, the hydrogen pressure is 6.0-16.0 MPa, and the liquid hourly space velocity is 0.5-2.5 h^-1And the vulcanization time is 5-16 h.

The sulfurization method of the invention is to convert the active metal component W, Ni into corresponding sulfide to obtain the sulfurized hydrocracking catalyst, wherein the sulfurization degree of each active metal in the catalyst is not lower than 80%.

The hydrocracking catalyst is particularly suitable for a one-stage series once-through hydrocracking process, and the hydrocracking operation conditions are as follows: the reaction temperature is 300-500 ℃, preferably 350-450 ℃; the pressure is 6-20 MPa, preferably 13-17 MPa; the liquid hourly space velocity is 0.5-3.0 h^-1Preferably 0.8 to 2.0 hours^-1(ii) a The volume ratio of the hydrogen to the oil is 400-2000: 1, preferably 800-1500: 1.

The hydrocracking catalyst disclosed by the invention is suitable for heavy raw materials in a wide range, the heavy raw materials comprise one or more of various hydrocarbon oils such as vacuum gas oil, coking gas oil, deasphalted oil, thermal cracking gas oil, catalytic cracking gas oil and catalytic cracking circulating oil, the heavy raw materials usually contain hydrocarbons with boiling points of 250-550 ℃, the nitrogen content can be 300-2500 [ mu ] g/g, and after the hydrocracking pretreatment process is carried out, the nitrogen content in the feed of the hydrocracking catalyst disclosed by the invention is less than 150 [ mu ] g/g, namely the nitrogen content in the feed of a reaction section of the hydrocracking catalyst is less than 150 [ mu ] g/g.

The hydrocracking catalyst prepared by the method is a bulk phase hydrocracking catalyst, which comprises a hydrogenation active metal component, an organic auxiliary agent and a carrier component, wherein the hydrogenation active metal component is W and Ni, and WS is obtained after vulcanization₂The average number of stacked layers is 5.0 to 7.0 layers, preferably 5.5 to 6.5 layers, WS₂The average length of the lamella is 4.0 to 6.0nm, preferably 4.5 to 5.5 nm.

In the hydrocracking catalyst provided by the invention, the organic auxiliaries are organic auxiliaries P1 and organic auxiliaries P2. The organic auxiliary agent P1 is organic phosphonic acid and/or carboxylic acid polymer. The organic auxiliary agent P2 is organic carboxylic acid. The content of the organic auxiliary agent is 4wt% -26 wt%, preferably 4wt% -16 wt% based on the weight of the hydrocracking catalyst. Wherein the content of the organic assistant P1 is 2 to 15 weight percent, preferably 2 to 8 weight percent, and the content of the organic assistant P2 is 2 to 11 weight percent, preferably 2 to 8 weight percent.

The hydrocracking catalyst of the invention takes the weight of the hydrocracking catalyst as a reference, the content of W calculated by oxide is 10wt% -50 wt%, preferably 15wt% -45 wt%, and the content of Ni calculated by oxide is 3wt% -45 wt%, preferably 5wt% -35 wt%.

In the hydrocracking catalyst, the W/Ni molar ratio is 0.05-1.2, preferably 0.1-1.0.

The hydrocracking catalyst comprises a carrier component and an amorphous oxide component, wherein the molecular sieve is a Y-type molecular sieve, preferably the following Y-type molecular sieve is used, and the properties of the Y-type molecular sieve are as follows: the specific surface area is 750-900 m²The crystal cell parameter is 2.423 nm-2.545 nm, the relative crystallinity is 95% -110%, and SiO₂/Al₂O₃The molar ratio is 7-60; the amorphous oxide component is an alumina component and a silica component.

The hydrocracking catalyst of the invention takes the weight of the hydrocracking catalyst as a reference, and the content of the molecular sieve is 3wt% -30 wt%, preferably 5wt% -25 wt%; the content of the amorphous oxide is 10wt% to 67wt%, preferably 20wt% to 63 wt%.

In the hydrocracking catalyst of the present invention, the content of silica in the amorphous oxide is 3wt% to 49wt%, preferably 5wt% to 48 wt%.

The hydrocracking catalyst prepared by the method of the invention is WS after being vulcanized₂The number of stacked layers is distributed as follows: the average stacking layer number is 5.0-7.0 layers, preferably 5.5-6.5 layers, and the number of the laminated layers with the stacking layer number of 5.0-7.0 accounts for 55-85% of the total laminated layers, preferably 60-80%; WS₂The sheet length distribution is as follows:the average length of the lamella is 4.0-6.0 nm, preferably 4.5-5.5 nm, and the number of the lamella with the lamella length of 4.0-6.0 nm accounts for 60.0-85.0%, preferably 65.0-80.0% of the total number of the lamellae.

The hydrocracking catalyst prepared by the method of the invention is WS after being vulcanized₂The distribution of the number of stacked layers is specifically as follows: the number of the layers with the number of the layers smaller than 3 accounts for 1% -8% of the total number of the layers, the number of the layers with the number of the layers from 3.0 to less than 5.0 accounts for 3% -15% of the total number of the layers, the number of the layers with the number of the layers from 5.0 to 7.0 accounts for 55% -85% of the total number of the layers, and the number of the layers with the number of the layers larger than 7 accounts for 8% -25% of the total number of the layers.

The hydrocracking catalyst prepared by the method of the invention is WS after being vulcanized₂The lamella length distribution is specifically as follows: the number of the lamella with the length of less than 4.0nm accounts for 5.0-25.0% of the total number of the lamellae, the number of the lamella with the length of 4.0-6.0 nm accounts for 60.0-85.0% of the total number of the lamellae, the number of the lamella with the length of more than 6.0-8.0 nm accounts for 1.0-15.0% of the total number of the lamellae, and the number of the lamella with the length of more than 8.0nm accounts for 0.5-4.0% of the total number of the lamellae.

The hydrocracking catalyst prepared by the method has the following properties: the specific surface area is 250 to 650m²The pore volume is 0.20 to 0.90 mL/g.

The hydrocracking catalyst can contain an auxiliary component according to the requirement, the auxiliary component is titanium and/or zirconium, and the weight content of the auxiliary component in the hydrocracking catalyst is less than 20% in terms of elements, and preferably 1-15%.

The hydrocracking catalyst is suitable for heavy raw materials in a wide range, the heavy raw materials comprise one or more of various hydrocarbon oils such as vacuum gas oil, coking gas oil, deasphalted oil, thermal cracking gas oil, catalytic cracking gas oil and catalytic cracking circulating oil, the heavy raw materials usually contain hydrocarbons with the boiling point of 250-550 ℃, the nitrogen content can be 300-2500 mug/g, and after the hydrocracking pretreatment process is carried out, the nitrogen content in the feed of the hydrocracking catalyst is smaller than 150 mug/g, namely the nitrogen content in the feed of a reaction section of the hydrocracking catalyst is smaller than 150 mug/g, further more than 10 mug/g, and even more than 50 mug/g.

The hydrocracking catalyst of the invention, after being vulcanized, WS₂The stacking has high layer number and small length, and is particularly concentrated on 5.0-7.0 layers with the length of 40-6.0 nm, more effective active phases are generated, the promotion effect among the active phases is stronger, and the hydrogenation activity of the catalyst is favorably improved.

The method of the invention comprises the steps of firstly carrying out co-current flow and coprecipitation reaction on a mixed solution containing Ni and partial W, an organic auxiliary agent P1 and a sodium metaaluminate alkaline solution to generate W, Ni and Al mixture slurry, carrying out primary aging for the first time, so that an active metal and an organic auxiliary agent P1 are chelated to form a macromolecular reticular complex, particles containing W, Ni and Al precipitates are large and regularly arranged, the hydrogenation active metal deposited previously has certain anchoring effect on the hydrogenation active metal deposited later, then adding the residual mixed solution of W, Al and Si, an organic auxiliary agent P2 and ammonia water into the aged slurry in a co-current flow manner to carry out reaction, then carrying out deep aging for the second time to prepare the tungsten, nickel, silicon and aluminum mixed slurry, so that the post-deposition process is more uniform and mild, different hydrogenation active metals are orderly deposited in a catalyst, the growth speed of metal oxide particles and the mutual contact probability between the active metals are controlled, WO₃The particle size of the product is suitable, the distribution of the product is well controlled, the generation of non-framework active metal and aluminum fragments is reduced, and WS in the vulcanized bulk phase catalyst is increased₂The stacking layer number, the lamella length are reduced, the morphology of the active phase is optimized, more effective active phases are generated, the mutual promotion effect is stronger, and the activity is higher. In addition, the method of the invention introduces the acid component, can well control the distribution of the acid component, promotes the mutual cooperation between the acid component and the hydrogenation active metal, and is beneficial to improving the activity and the selectivity of the catalyst.

The hydrocracking catalyst still has high activity and stability under the condition of high-nitrogen content feeding (less than 150 mug/g), even can reach the activity equivalent to that of the currently widely applied medium oil type catalyst when the catalyst is operated under low nitrogen (less than 10 mug/g), and meanwhile, the catalyst still has good stability, medium oil selectivity and good product quality when the catalyst is operated under the condition of high nitrogen, and still has good activity stability.

Detailed Description

In the present invention, the specific surface area and the pore volume are measured by a low-temperature liquid nitrogen adsorption method, and the mechanical strength is measured by a side pressure method. In the present invention, WS in bulk catalyst₂The number of stacked layers and the length of the sheet layer were measured by a transmission electron microscope. The hydrocracking catalyst of the invention is vulcanized, namely a non-vulcanized hydrocracking catalyst is vulcanized into a vulcanized hydrocracking catalyst, namely a vulcanized hydrocracking catalyst. In the present invention, wt% is a mass fraction and v% is a volume fraction.

In the invention, the degree of vulcanization is measured by an X-ray photoelectron spectrometer (XPS), and the percentage of the content of the active metal in a vulcanized state in the total content of the active metal is the degree of vulcanization of the active metal.

Example 1

Respectively dissolving nickel chloride, ammonium metatungstate, polymaleic acid (molecular weight is 450) and hydroxyethylidene diphosphonic acid in deionized water to prepare a mixed solution A, wherein the weight concentration of Ni in NiO in the mixed solution A is 42g/L, and W in WO₃The weight concentration is 30g/L, the weight concentration of polymaleic acid (molecular weight is 450) is 9g/L, and the weight concentration of hydroxyethylidene diphosphonic acid is 11 g/L. Respectively dissolving ammonium metatungstate, aluminum chloride and citric acid in deionized water, adding dilute water glass solution to prepare mixed solution B, wherein W in the mixed solution B is WO₃The weight concentration is 24g/L, Al is Al₂O₃The weight concentration is 28g/L, Si is SiO₂The calculated weight concentration is 40g/L, and the weight concentration of the citric acid is 19 g/L. Adding 500mL of deionized water into a reaction tank, and adding Al according to the weight concentration₂O₃And adding 32g/L sodium metaaluminate solution and the solution A into a reaction tank in parallel, keeping the gelling temperature at 56 ℃, controlling the pH value at 7.6 in the process of parallel-flow gelling reaction, and controlling the gelling time at 30 minutes to generate precipitate slurry I containing nickel, tungsten and aluminum. Aging the obtained precipitate slurry I at 75 deg.C under the condition of aging pH value of 6.9 for 0.7 hr under stirringThe stirring was carried out at 175 rpm. After ageing, adding the mixed solution B and 10wt% of ammonia water into the aged slurry I in a cocurrent manner, keeping the gel forming temperature at 64 ℃, controlling the pH value at 7.6 in the cocurrent gel forming reaction process, controlling the gel forming time at 2 hours, obtaining nickel, tungsten, silicon and aluminum precipitate slurry II after the reaction is finished, adding a Y-type molecular sieve suspension (prepared according to CN102441411A example 3) modified by hydrothermal treatment into the precipitate slurry II, controlling the addition amount of the Y-type molecular sieve to be 10wt% of the total weight of the catalyst, controlling the property of the Y-type molecular sieve in Table 6, starting ageing under the stirring condition, controlling the stirring rotating speed at 440 r/min, the ageing temperature at 75 ℃, controlling the pH value at 8.3, controlling the ageing time at 2.8 hours, filtering the aged slurry, drying a filter cake at 100 ℃ for 12 hours, rolling, extruding and forming. Washed 6 times with deionized water at room temperature. The wet strands were then dried at 80 ℃ for 10 hours to give catalyst A. The catalyst composition and the main properties are shown in table 1.

Example 2

According to the method of example 1, according to the component content proportion of the catalyst B in Table 1, nickel nitrate, ammonium metatungstate, zirconium oxychloride and ethylenediamine tetramethylene phosphonic acid are added into a dissolving tank 1 to prepare a mixed solution A, ammonium metatungstate, aluminum chloride and tartaric acid are added into a dissolving tank 2 to be dissolved in deionized water, water glass is added to prepare a mixed solution B, 700mL of deionized water is added into a reaction tank, and the weight concentration of Al is calculated according to the weight concentration of Al₂O₃And adding 40g/L sodium metaaluminate solution and the mixed solution A into a reaction tank in parallel, keeping the gelling temperature at 60 ℃, controlling the pH value at 7.4 in the process of parallel-flow gelling reaction, and controlling the gelling time at 60 minutes to generate precipitate slurry I containing nickel, tungsten, aluminum and zirconium. Aging the obtained precipitate slurry I at 76 deg.C for 0.7 hr with the aging pH value controlled at 7.0, and stirring at 210 rpm. After aging is finished, the mixed solution B and 12wt% ammonia water are added into the slurry I in a cocurrent manner, the gelling temperature is kept at 55 ℃, the pH value is controlled at 8.2 in the cocurrent gelling reaction process, the gelling time is controlled at 2.2 hours, a nickel, tungsten, zirconium, silicon and aluminum precipitate slurry II is obtained after the reaction is finished, and a Y-type molecular sieve suspension modified by hydrothermal treatment (according to CN 102441) is added into the precipitate slurry II411A, prepared in example 3), the addition amount of the Y-type molecular sieve is 8wt% of the total weight of the catalyst, the properties of the Y-type molecular sieve are shown in Table 6, the aging is started under the stirring condition, the stirring rotating speed is 440 r/min, the aging time is 3.8 hours, the aging temperature is 78 ℃, and the aging pH value is controlled at 8.4. Filtering the aged slurry, drying the filter cake at 100 ℃ for 14 hours, extruding into strips for molding, washing with deionized water for 5 times, and drying wet strips at 90 ℃ for 11 hours to obtain the final catalyst B, wherein the composition and main properties of the catalyst are shown in Table 1.

Example 3

According to the method of example 1, according to the component content proportion of catalyst C in Table 1, nickel chloride, ammonium metatungstate and aminotrimethylene phosphonic acid are added into a dissolving tank 1 to prepare a mixed solution A, aluminum chloride, ammonium metatungstate and citric acid are added into a dissolving tank 2 to be dissolved in deionized water, water glass is added to prepare a mixed solution B, 800mL of deionized water is added into a reaction tank, and the weight concentration of Al is calculated₂O₃Adding 36g/L of sodium metaaluminate solution and the mixed solution A into a reaction tank in parallel, keeping the gelling temperature at 50 ℃, controlling the pH value at 7.8 in the process of parallel-flow gelling reaction, and controlling the gelling time at 70 minutes to generate precipitate slurry I containing nickel, tungsten and aluminum. Aging the obtained precipitate slurry I at 78 deg.C under stirring at 170 rpm for 0.8 hr with aging pH controlled at 6.9. After aging, adding the mixed solution B and ammonia water with the concentration of 13wt% into the slurry I in a concurrent flow manner, keeping the gelling temperature at 50 ℃, controlling the pH value at 7.7 in the concurrent flow gelling reaction process, controlling the gelling time at 2.8 hours, obtaining nickel, tungsten, silicon and aluminum precipitate slurry II after the reaction is finished, adding a Y-type molecular sieve suspension (prepared according to CN102441411A example 3) modified by hydrothermal treatment into the precipitate slurry II, adding the Y-type molecular sieve in an amount accounting for 8wt% of the total weight of the catalyst, wherein the property of the Y-type molecular sieve is shown in Table 6, aging is started under stirring conditions, the stirring rotation speed is 360 r/min, the aging time is 4.0 hours, the aging temperature is 75 ℃, and the aging pH value is controlled at 8.2. Filtering the aged slurry, drying the filter cake at 90 deg.C for 14 hr, extruding to form strip, washing with water for 6 times, and drying the wet strip at 100 deg.C for 10 hr to obtain final catalyst CThe composition and main properties are shown in Table 1.

Example 4

According to the method of example 1, according to the component content proportion of catalyst D in Table 1, adding nickel chloride, ammonium metatungstate and aminotrimethylene phosphonite into dissolving tank 1 to prepare mixed solution A, adding aluminum nitrate, ammonium metatungstate and malic acid into dissolving tank 2 to dissolve in deionized water, adding water glass to prepare mixed solution B, and adding Al in weight concentration₂O₃Adding 35g/L sodium metaaluminate solution and the mixed solution A into a reaction tank in parallel, keeping the gelling temperature at 45 ℃, controlling the pH value at 7.4 in the process of parallel-flow gelling reaction, and controlling the gelling time at 80 minutes to generate precipitate slurry I containing nickel, tungsten and aluminum. Aging the obtained precipitate slurry I at 75 deg.C for 0.8 hr with the aging pH value controlled at 7.1, and stirring at 240 rpm. After aging, adding the mixed solution B and ammonia water with the concentration of 10wt% into the slurry I in a concurrent flow manner, keeping the gelling temperature at 55 ℃, controlling the pH value at 7.5 in the concurrent flow gelling reaction process, controlling the gelling time at 2.1 hours, obtaining nickel, tungsten, silicon and aluminum precipitate slurry II after the reaction is finished, adding a Y-type molecular sieve suspension (prepared according to CN102441411A example 3) modified by hydrothermal treatment into the precipitate slurry II, adding the Y-type molecular sieve in an amount accounting for 10wt% of the total weight of the catalyst, wherein the property of the Y-type molecular sieve is shown in Table 6, aging is started under stirring conditions, the stirring rotation speed is 430 revolutions per minute, the aging time is 4.6 hours, the aging temperature is 78 ℃, and the aging pH value is controlled at 8.3. Filtering the aged slurry, drying the filter cake at 100 ℃ for 12 hours, extruding into strips for forming, washing with deionized water for 3 times, and drying wet strips at 90 ℃ for 16 hours to obtain the final catalyst D, wherein the composition and the main properties are shown in Table 1.

Comparative example 1

The preparation method disclosed in CN101239324A comprises the following specific steps:

(1) respectively mixing nickel chloride, aluminum chloride and ammonium metatungstate solution deionized water in a 5L reaction tank, and adding 1000 ml of deionized water for dilution;

(2) preparation of a mixture containing SiO as in example 1₂Dilute water glass with same contentAdding the solution obtained in the step (2) into the solution obtained in the step (1) under stirring;

(3) adding ammonia water into the mixture of (1) and (2) under stirring until the pH value is 5.2;

(4) the configuration contains WO in example 1₃Adding sodium tungstate solution with the same content into the mixture of (1) + (2) + (3) under stirring;

(5) continuously adding ammonia water until the pH value is 7.6;

(6) the whole gelling process is carried out at 60 ℃;

(7) standing and aging the mixture at 75 ℃ for 3.5 hours, and controlling the pH value to be 7.8 after the aging is finished; adding Y-type molecular sieve suspension (prepared according to CN102441411A example 3) before aging, wherein the addition amount of the Y-type molecular sieve is 10wt% of the total weight of the catalyst, and the properties of the Y-type molecular sieve are shown in Table 6;

(8) filtering, drying in an oven at 100 deg.C for 12 hr, grinding, and extruding with a 3 mm-diameter orifice plate; washing with ammonium acetate solution pH =8.8 at room temperature; then dried in an oven at 80 ℃ for 10 hours and roasted at 530 ℃ for 4 hours to obtain a reference agent E, and the composition and the main properties of the catalyst are shown in Table 1.

Comparative example 2

The preparation method disclosed in CN103055923A comprises the following steps:

(1) preparing an acid solution A: nickel chloride and ammonium metatungstate were mixed in a 5l vessel and diluted with 1000 ml of deionized water according to the catalyst composition of example 1. Preparation of a mixture containing SiO as in example 1₂The same amount of dilute water glass solution was added to the above mixed salt solution with stirring.

(2) Preparing an alkaline solution B: the formulation contains Al as in example 1₂O₃Alkaline sodium metaaluminate solution with the same content.

(3) Mixing solution A, solution B and CO₂And adding the gas into a gelatinizing tank in a parallel flow manner to gelatinize, wherein the gelatinizing temperature is kept at 60 ℃, and the pH value is 7.6. Wherein CO is used₂Gas concentration 45v%, CO addition₂Total amount of gas and Al in alkaline solution₂O₃The molar ratio is 3, the flow rate of A, B solution is adjusted to ensure that the simultaneous dripping is finished so as to ensure that the catalyst is dripped offThe distribution is uniform and the composition is unchanged.

(4) After the completion of the gelling, a suspension of Y-type molecular sieve (prepared according to CN102441411A example 3) was added under stirring, the amount of Y-type molecular sieve was 10wt% based on the total weight of the catalyst, the properties of the Y-type molecular sieve are shown in table 6, and the Y-type molecular sieve was uniformly dispersed in the mixed slurry obtained by gelling, and left to stand at about 75 ℃ for aging for 3.5 hours.

(5) And (4) filtering the material obtained in the step (4), drying a filter cake for 12 hours at 100 ℃, rolling, extruding and forming. Washed with deionized water at room temperature. Then dried at 80 ℃ for 10 hours and calcined at 530 ℃ for 4 hours to obtain a catalyst F. The catalyst composition and the main properties are shown in table 1.

Comparative example 3

In the preparation process of comparative example 3, the active metal, silicon and aluminum solution and the precipitant are reacted at one time to generate nickel, tungsten, silicon and aluminum precipitate slurry, and the stepwise reaction and the secondary aging are not performed. The specific steps for preparing the catalyst are as follows:

respectively dissolving nickel chloride, aluminum chloride, ammonium metatungstate and water glass in deionized water to prepare a mixed solution, wherein the weight concentration of NiO in the mixed solution is 42g/L, and Al₂O₃Has a weight concentration of 45g/L, WO₃Has a weight concentration of 31g/L, SiO₂The weight concentration of (B) is 40 g/L. Adding 500mL of deionized water into a reaction tank, adding 10wt% ammonia water and the mixed solution into the reaction tank in a concurrent flow manner, keeping the gelling temperature at 60 ℃, controlling the pH value at 7.6 in the concurrent flow gelling reaction process, and controlling the gelling time at 2.5 hours to generate precipitate slurry containing nickel, tungsten, silicon and aluminum. Adding a Y-type molecular sieve suspension modified by hydrothermal treatment (prepared according to CN102441411A example 3) into the precipitate slurry, wherein the addition amount of the Y-type molecular sieve is 10wt% of the total weight of the catalyst, the properties of the Y-type molecular sieve are shown in Table 6, uniformly stirring, aging, controlling the aging temperature at 75 ℃, the pH value at 7.8 and the aging time at 3.5 hours, filtering the aged slurry, drying a filter cake at 120 ℃ for 8 hours, rolling, extruding and forming. Washed 6 times with deionized water at room temperature. The wet strands were then dried at 80 ℃ for 10 hours and calcined at 530 ℃ for 4 hours to give catalyst G. The catalyst composition and the main properties are shown in table 1.

Comparative example 4

The preparation method disclosed in CN104588082A comprises the following steps:

adding nickel nitrate and aluminum chloride solution into the dissolving tank 1 to prepare working solution A, and adding aluminum chloride, ammonium metatungstate and dilute water glass into the dissolving tank 2 to prepare working solution B. Adding ammonia water into the solution A under stirring, keeping the gelling temperature at 60 ℃, controlling the pH value at 7.6 when the gelling is finished, and controlling the gelling time at 30 minutes to generate nickel and aluminum containing precipitate slurry I. Adding 500mL of deionized water into a reaction tank, adding ammonia water and the solution B into the reaction tank in a cocurrent manner, keeping the gelling temperature at 60 ℃, controlling the pH value to be 7.8 in the cocurrent gelling reaction process, and controlling the gelling time to be 2 hours to generate precipitate slurry II containing tungsten, silicon and aluminum. Mixing the two types of slurry containing the precipitate, adding a Y-shaped molecular sieve suspension (prepared according to CN102441411A example 3) modified by hydrothermal treatment into the two types of slurry containing the precipitate under the condition of continuous stirring, wherein the addition amount of the Y-shaped molecular sieve accounts for 10wt% of the total weight of the catalyst, the property of the Y-shaped molecular sieve is shown in Table 6, uniformly dispersing the Y-shaped molecular sieve in the mixed slurry obtained by gelling, aging at 75 ℃ for 3.5 hours, filtering, drying at 100 ℃ for 12 hours, rolling, extruding and forming. Washed with ionized water at room temperature. Then dried at 80 ℃ for 10 hours and calcined at 530 ℃ for 4 hours to obtain a catalyst H. The catalyst composition and the main properties are shown in table 1.

Example 5

This example is WS in the sulfided catalyst₂Average wafer length and average number of stacked layers. The TEM picture of the prepared bulk phase catalyst is subjected to statistical analysis, and the statistical area is about 20000nm²Statistical WS₂The total number of slices exceeds 400. Bulk phase catalyst WS according to the calculation formulae (1) and (2)₂The average length of the sheets and the average number of stacked layers were statistically calculated and the results are shown in Table 3.

（1）

（2）

In the formulas (1) and (2),L _Ais WS₂The average length of the sheets is,L _iis WS₂Lamella length, nm;n _iis of length ofL _iWS (A) of₂The number of the sheets is equal to the number of the sheets,N _Ais WS₂The average number of stacked layers;N _iis WS₂The number of layers is stacked,m _iis stacked with the number of layers ofN _iWS (A) of₂Number of slices.

The catalyst A, B, C, D of the invention and the catalyst E, F, G, H of the comparative example were used to perform sulfidation on a hydrogenation microreactor, the catalyst loading volume was 10mL, and the sulfiding agent was CS₂The sulfurized oil being cyclohexane, CS₂The amount of sulfur used is 110% of the theoretical amount of sulfur required. The prevulcanization conditions are as follows: the temperature of the reactor is 110 ℃, the vulcanizing reagent is added, the vulcanizing reaction temperature is 350 ℃, the hydrogen pressure is 14.5MPa, and the space velocity is 1.2h^-1And the time is 10 h.

Example 6

This example is an evaluation experiment of the activity of the catalyst of the present invention and is compared with the catalyst of the comparative example. A comparative evaluation test was conducted on a 200mL compact hydrogenation apparatus using the A, B, C, D catalyst of the present invention and the E, F, G, H catalyst of comparative example under the following conditions: the total reaction pressure is 14.7MPa, the volume ratio of hydrogen to oil is 1200, and the liquid hourly space velocity is 1.5h^-1The evaluation raw material was Sauter VGO heavy distillate oil, and the main properties thereof are shown in Table 4, and Table 5 shows the evaluation results of the catalyst after 500 hours of operation.

As can be seen from Table 2, the catalysts of the present invention have WS as compared with the catalysts of the comparative examples without substantially changing the amount of active metal₂The stacking layer number is increased, the average length of the lamella is reduced, and the number of hydrogenation active centers is obviously increased. From the results of the evaluation, table 5 shows that the activity and the middle oil selectivity of the catalyst A, B, C, D prepared by the present invention are superior to those of the reference. The catalyst prepared by the method has high utilization rate of active metal and hydrogenation reaction of the catalystThe activity is obviously improved.

By adopting the catalyst A of the invention, the catalyst is continuously operated for 2500 hours under the operating conditions, and the product yield and the property are basically not changed, which shows that the hydrocracking catalyst of the invention has good activity and stability for processing high-nitrogen raw materials. While the catalyst E, F, G, H of the comparative example is required to continuously increase the reaction temperature under the condition of ensuring the initial product yield and properties, the product yield and properties are obviously reduced even after the reaction temperature is increased for 2500 hours of continuous operation due to serious catalyst deactivation.

TABLE 1 compositions and Properties of catalysts prepared in examples and comparative examples

Catalyst numbering	A	B	C	D	E	F	G	H
									Catalyst composition
Ni, wt% calculated as NiO	19	17	18	22	19	19	19	19
									W, in WO₃Calculated by weight percent	28	26	27	26	28	28	28	28
Si in SiO₂Calculated by weight percent	20	22	21	20	22	22	22	22
									Al, with Al₂O₃Calculated by weight percent	24	25	26	25	Balance of	Balance of	Balance of	Balance of
Organic auxiliary agent (wt%)	Balance of	Balance of	Balance of	Balance of	-	-	-	-
									Others/wt%	-	ZrO₂/3.0	-	-	-	-	-	-
Catalyst Properties
									Specific surface area, m²/g	390	386	384	389	354	391	365	375
Pore volume, mL/g	0.411	0.403	0.397	0.395	0.365	0.415	0.381	0.389
									Mechanical Strength, N/mm	18.5	19.2	18.7	19.6	17.7	17.8	17.1	17.3

TABLE 2 WS in catalysts obtained in examples and comparative examples₂Average number of stacked layers and average sheet length of

Catalyst numbering	Average number of stacked layers N_A	Average lamella length L_A，nm
			A	6.16	4.86
B	6.13	4.89
			C	6.08	4.92
D	6.05	4.90
			E	4.02	6.68
F	4.18	6.89
			G	3.98	7.01
H	4.05	6.92

TABLE 3 WS in bulk catalysts₂Distribution of the number of stacked layers and the length of the sheet

Catalyst numbering	A	B	C	D	E	F	G	H
									Distribution of number of lamellae,%
< 3 layers	3.18	3.01	3.60	3.32	15.35	13.25	14.93	14.85
									3 to less than 5 layers	11.51	11.87	11.42	11.51	76.25	75.95	75.09	75.26
5 to 7 layers	74.32	74.85	74.08	74.58	7.38	9.05	8.11	7.91
									Greater than 7 layers	10.99	10.27	10.90	10.59	1.02	1.75	1.87	1.98
Length distribution of%
									＜4nm	18.56	18.32	18.38	18.35	5.69	5.26	6. 08	4.99
4~6nm	73.96	73.75	74.11	74.09	12.36	13.95	14.02	14.21
									Greater than 6 to 8nm	6.34	6.77	6.45	6.38	71.25	72.22	71.94	72.08
＞8nm	1.14	1.16	1.06	1.18	10.70	8.57	7.96	8.72

TABLE 4 Primary Properties of the base oils

Item	Analysis results
		Density (20 ℃ C.), g/cm³	0.9205
Range of distillation range, deg.C	314-539
		S，µg/g	10100
N，µg/g	1920
		Carbon residue in wt%	0.18
Freezing point, deg.C	33

TABLE 5 catalyst evaluation results

Catalyst numbering	A	B	C	D
					Reaction temperature of	389	390	390	389
Nitrogen content in the feed, microgram/g	110.1	93.6	94.7	90.2
					Product distribution and Properties, wt.%
Heavy naphtha (82-138 ℃ C.)
					Yield, wt.%	8.2	8.5	8.1	8.7
Aromatic hydrocarbon, wt%	52．7	53.6	52.9	53.1
					Jet fuel (138-249 deg.C)
Yield, wt.%	28.3	28.1	28.4	28.3
					Smoke point, mm	31	32	32	31
Diesel oil (249-371 deg.C)
					Yield, wt.%	28.5	28.7	28.6	28.5
Cetane number	69.9	70.5	70.7	69.6
					Tail oil (A)>371℃）
Yield, wt.%	30.3	30.4	30.1	30.5
					BMCI value	7.5	7.1	6.8	7.7
Medium oil selectivity, wt%	81.5	81.6	81.5	81.7

TABLE 5 continuation

Catalyst numbering	E	F	G	H
					Reaction temperature of	396	396	395	396
Nitrogen content in the feed, microgram/g	90.6	105.9	102.7	89.4
					Product distribution, wt%
Heavy naphtha (82-138 ℃ C.)
					Yield, wt.%	9.8	10.0	9.9	9.7
Aromatic hydrocarbon, wt%	63.6	62.1	63.3	62.8
					Jet fuel (138-249 deg.C)
Yield, wt.%	18.2	18.8	19.0	18.9
					Smoke point, mm	22	24	24	23
Diesel oil (249-371 deg.C)
					Yield, wt.%	20.4	20.2	19.9	20.1
Cetane number	61.5	61.9	60.8	61.1
					Tail oil (A)>371℃）
Yield, wt.%	42.0	42.2	42.1	42.5
					BMCI value	18.5	20.9	19.1	21.6
Medium oil selectivity, wt%	66.5	67.5	67.1	67.8

TABLE 6 Properties of modified Y-type molecular sieves relating to examples and comparative examples

Relative degree of crystallinity,%	95
		Cell parameter, nm	2.439
SiO₂/Al₂O₃，mol/mol	12.05
		Specific surface area, m²/g	839
Pore volume, mL/g	0.506
		1.7 to 10nm secondary pores occupying the total pore volume%	48.0
Total infrared acid, mmol/g	0.999
		Na₂O，wt%	0.093

Claims

1. A method of preparing a hydrocracking catalyst, comprising:

wherein the organic assistant P1 is added in the step (2), and the organic assistant P2 is added in the step (3); the organic auxiliary agent P1 is organic phosphonic acid and/or carboxylic acid polymer, the organic phosphonic acid is one or more of ethylenediamine tetramethylene phosphonic acid, hydroxyethylidene diphosphonic acid, polyalcohol phosphonate ester, polyaminopolyether methylene phosphonic acid, 1,2, 4-tricarboxylic acid-2-phosphonic butane, hydroxyphosphonoacetic acid, aminotrimethylene phosphonic acid and diethylenetriamine pentamethylene phosphonic acid; the molecular weight of the carboxylic acid polymer is 400-5000, and the carboxylic acid polymer is selected from one or more of polyacrylic acid, polymethacrylic acid, polymaleic acid, polyaspartic acid, polyepoxysuccinic acid, acrylic acid-hydroxypropyl acrylate copolymer and maleic acid-acrylic acid copolymer; the organic auxiliary agent P2 is an organic carboxylic acid with the carbon number of less than 8, and the organic carboxylic acid is one or more of citric acid, tartaric acid, gluconic acid, salicylic acid and malic acid.

2. The method of claim 1, wherein: the organic phosphonic acid is one or more of ethylenediamine tetramethylene phosphonic acid, hydroxyethylidene diphosphonic acid and amino trimethylene phosphonic acid; the carboxylic acid polymer is one or more of polyacrylic acid, polymethacrylic acid, polymaleic acid, polyaspartic acid and polyepoxysuccinic acid.

3. The method of claim 1, wherein: in the step (2), the organic auxiliary agent P1 is independently added in a concurrent flow manner, and/or is added when the mixed solution A is prepared; the organic auxiliary agent P2 is added separately and concurrently in the step (3) and/or is added when preparing the mixed solution B.

4. The method of claim 1, wherein: adding an organic assistant P1 in the step (2), wherein the adding amount of the organic assistant P1 is 2-50 g/L based on the volume of the mixed solution A; wherein the organic assistant P2 is added in the step (3), and the adding amount of the organic assistant P2 is 2-40 g/L based on the volume of the mixed solution B.

5. The method of claim 4, wherein: adding an organic assistant P1 in the step (2), wherein the adding amount of the organic assistant P1 is 5-40 g/L based on the volume of the mixed solution A; wherein the organic assistant P2 is added in the step (3), and the adding amount of the organic assistant P2 is 3-30 g/L based on the volume of the mixed solution B.

6. The method of claim 1, wherein: in the mixed solution A in the step (1), the weight concentration of Ni in NiO is 5-100 g/L, and W in WO₃The calculated weight concentration is 2-60 g/L; in the mixed solution B, W is WO₃The weight concentration is 2-50 g/L, Si is SiO₂The weight concentration is 10-100 g/L, Al is Al₂O₃The weight concentration is 2-60 g/L.

7. The method of claim 6, wherein: in the mixed solution A in the step (1), the weight concentration of Ni in NiO is 10-80 g/L, and W in WO₃The calculated weight concentration is 10-50 g/L; in the mixed solution B, W is WO₃The weight concentration is 4-40 g/L, Si is SiO₂The weight concentration is 20-80 g/L, Al is Al₂O₃The weight concentration is 2-50 g/L.

8. The method of claim 1, wherein: the W introduced into the catalyst by the mixed solution A in the step (2) accounts for 40-80% of the total W in the catalyst obtained in the step (4) in terms of oxide, and the W introduced into the catalyst by the mixed solution B in the step (3) accounts for 20-60% of the weight of the W in the catalyst obtained in the step (4) in terms of oxide.

9. The method of claim 8, wherein: the W introduced into the catalyst by the mixed solution A in the step (2) accounts for 51-75% of the total W in the catalyst obtained in the step (4) in terms of oxide, and the W introduced into the catalyst by the mixed solution B in the step (3) accounts for 25-49% of the weight of the W in the catalyst obtained in the step (4) in terms of oxide.

10. The method of claim 1, wherein: the concentration of the sodium metaaluminate alkaline solution in the step (2) is Al₂O₃15-100 g/L; the gelling reaction conditions in the step (2) are as follows: the reaction temperature is 20-90 ℃, the pH value is controlled to be 6.0-10.0, and the gelling time is 0.2-2.0 hours.

11. The method of claim 10, wherein: the concentration of the sodium metaaluminate alkaline solution in the step (2) is Al₂O₃The weight is 20-80 g/L; the gelling reaction conditions in the step (2) are as follows: the reaction temperature is 30-70 ℃, the pH value is controlled to be 7.0-9.0, and the gelling time is 0.3-1.5 hours.

12. The method of claim 1, wherein: the weight concentration of the ammonia water in the step (3) is 5-15%; in the step (3), the reaction conditions of the gelling reaction are as follows: the reaction temperature is 20-90 ℃, the pH value is controlled to be 6.0-11.0, and the gelling time is 0.5-4.0 hours.

13. The method of claim 12, wherein: in the step (3), the reaction conditions of the gelling reaction are as follows: the reaction temperature is 30-80 ℃, the pH value is controlled to be 6.5-9.0, and the gelling time is 1.0-3.0 hours.

14. The method of claim 1, wherein: in the step (2), Al introduced into the catalyst through sodium metaaluminate accounts for 10-75 wt% of the weight of Al in the catalyst obtained in the step (4) in terms of oxide.

15. The method of claim 14, wherein: in the step (2), Al introduced into the catalyst through sodium metaaluminate accounts for 20-70 wt% of the weight of Al in the catalyst obtained in the step (4) in terms of oxide.

16. The method of claim 1, wherein: in the step (3), the Si and Al introduced into the catalyst through the mixed solution B account for 20-75 wt% of the weight of the Si and Al in the catalyst obtained in the step (4) in terms of oxide, wherein the Si accounts for 5-80 wt% of the total weight of the Si and Al introduced into the catalyst through the mixed solution B in terms of silicon oxide.

17. The method of claim 16, wherein: in the step (3), the Si and Al introduced into the catalyst through the mixed solution B account for 25-65 wt% of the weight of the Si and Al in the catalyst obtained in the step (4) in terms of oxide, wherein the Si accounts for 20-75 wt% of the total weight of the Si and Al introduced into the catalyst through the mixed solution B in terms of silicon oxide.

18. The method of claim 1, wherein: the aging conditions in step (2) are as follows: the aging temperature is 40-90 ℃, the pH value during aging is controlled to be 6.0-8.0, the aging time is 0.1-1.0 hour, the aging is carried out under stirring, and the stirring speed is 100-300 r/m.

19. The method of claim 18, wherein: the aging conditions in step (2) are as follows: the aging temperature is 50-80 ℃, the pH value during aging is controlled to be 6.5-7.5, and the aging time is 0.2-0.8 hours; the aging is carried out under stirring, and the stirring speed is 150-250 rpm.

20. A method according to claim 1 or 18, characterized by: the aging conditions in step (3) are as follows: the aging temperature is 40-90 ℃, the pH value during aging is controlled to be 7.5-11.0, the aging time is 1.5-6.0 hours, the aging is carried out under stirring, and the stirring speed is 300-500 rpm.

21. The method of claim 20, wherein: the aging conditions in step (3) are as follows: the aging temperature is 50-80 ℃, the pH value during aging is controlled to be 7.5-9.5, and the aging time is 2.0-5.0 hours; the aging is carried out under stirring, and the stirring speed is 300-450 rpm.

22. The method of claim 20, wherein: the pH value of the aging in the step (3) is at least 0.5 higher than that of the aging in the step (2).

23. The method of claim 22, wherein: the pH value of the aging in the step (3) is at least 1.0 higher than that of the aging in the step (2).

24. The method of claim 1, wherein: the drying conditions before the molding in the step (4) are as follows: drying for 1-48 hours at 40-120 ℃, wherein the drying conditions after molding are as follows: drying the mixture for 1 to 48 hours at a temperature of between 40 and 120 ℃.

25. The method of claim 24, wherein: the drying conditions before the molding in the step (4) are as follows: the drying conditions were as follows: drying for 4-36 hours at 60-110 ℃; the drying conditions after molding were: drying the mixture for 4 to 36 hours at a temperature of between 60 and 110 ℃.

26. The method of claim 1, wherein: the molecular sieve is a Y-type molecular sieve.

27. The method of claim 26, wherein: the Y-type molecular sieve has the following properties: the specific surface area is 750-900 m²The crystal cell parameter is 2.423 nm-2.545 nm, the relative crystallinity is 95% -110%, and SiO₂/Al₂O₃The molar ratio is 7-60.

28. The method of claim 1, wherein: in the preparation process of the hydrocracking catalyst, an auxiliary component such as Ti and/or Zr is added, and the weight content of the auxiliary component in the hydrocracking catalyst is less than 20% in terms of elements.

29. The method of claim 28, wherein: adding a compound containing an auxiliary component in the process of preparing the mixed solution A, wherein the weight content of the auxiliary component in the hydrocracking catalyst is less than 15% in terms of elements.

30. The method of claim 1, wherein: and (3) vulcanizing the hydrocracking catalyst in the step (4) to prepare a vulcanized hydrocracking catalyst, wherein the vulcanization degree of each active metal in the catalyst is not lower than 80%.

31. The method of claim 1, wherein: in the hydrocracking catalyst in the step (4), the content of the organic auxiliary agent is 4-26 wt% based on the weight of the hydrocracking catalyst; wherein the content of the organic assistant P1 is 2 to 15 weight percent, and the content of the organic assistant P2 is 2 to 11 weight percent.

32. The method of claim 31, wherein: in the hydrocracking catalyst in the step (4), the content of the organic auxiliary agent is 4-16 wt% based on the weight of the hydrocracking catalyst; wherein the content of the organic assistant P1 is 2 to 8 weight percent, and the content of the organic assistant P2 is 2 to 8 weight percent.

33. The method of claim 31, wherein: based on the weight of the hydrocracking catalyst, the content of W is 10-50 wt% calculated by oxide, and the content of Ni is 3-45 wt% calculated by oxide.

34. The method of claim 33, wherein: based on the weight of the hydrocracking catalyst, the content of W is 15wt% -45 wt% calculated by oxide, and the content of Ni is 5wt% -35 wt% calculated by oxide.

35. The method of claim 33, wherein: the W/Ni molar ratio of the obtained hydrocracking catalyst is 0.05-1.2.

36. The method of claim 35, wherein: the W/Ni molar ratio of the obtained hydrocracking catalyst is 0.1-1.0.

37. The method of claim 31, wherein: based on the weight of the hydrocracking catalyst, the content of the molecular sieve is 3wt% -30 wt%, the content of the amorphous oxide is 10wt% -67 wt%, and the content of silicon oxide in the amorphous oxide is 3wt% -49 wt%.

38. The method of claim 37, wherein: based on the weight of the hydrocracking catalyst, the content of the molecular sieve is 5wt% -25 wt%, the content of the amorphous oxide is 20wt% -63 wt%, and the content of silicon oxide in the amorphous oxide is 5wt% -48 wt%.

39. A method according to claim 1 or 30, characterized by: after said hydrocracking catalyst has been sulphided, WS₂An average number of stacked layers of 5.0 to 7.0, WS₂The average length of the lamella is 4.0-6.0 nm.

40. The method of claim 39, wherein: after said hydrocracking catalyst has been sulphided, WS₂An average number of stacked layers of 5.5 to 6.5, WS₂The average length of the lamella is 4.5-5.5 nm.

41. A method according to claim 1 or 30, characterized by: after said hydrocracking catalyst has been sulphided, WS₂The number of stacked layers is distributed as follows: the number of the stacked layers is 5.0-7.0, and the number of the layers accounts for 55-85% of the total number of the layers; WS₂The sheet length distribution is as follows: the number of the lamella with the lamella length of 4.0-6.0 nm accounts for 60.0-85.0% of the total number of the lamellae.

42. The method of claim 41, whereinIs characterized in that: after said hydrocracking catalyst has been sulphided, WS₂The number of stacked layers is distributed as follows: the number of stacked layers is 5.0-7.0, and the number of the stacked layers accounts for 60-80% of the total number of the stacked layers; WS₂The sheet length distribution is as follows: the number of the sheets with the length of 4.0-6.0 nm accounts for 65.0-80.0% of the total number of the sheets.