WO2023036154A1

WO2023036154A1 - Highly active and hydrothermally stable catalyst and preparation method therefor

Info

Publication number: WO2023036154A1
Application number: PCT/CN2022/117397
Authority: WO
Inventors: 吴青; 臧甲忠; 李滨; 范景新; 孙振海; 赵云; 郭健; 周微; 宫毓鹏; 侯立伟
Original assignee: 中海油天津化工研究设计院有限公司; 中国海洋石油集团有限公司
Priority date: 2021-09-07
Filing date: 2022-09-06
Publication date: 2023-03-16
Also published as: CN113477247A; CN113477247B

Abstract

A highly active and hydrothermally stable catalyst and a preparation method therefor. The catalyst is prepared by mixing highly active and hydrothermally stable catalyst powder with a binder and a forming agent and forming a spherical or strip-shaped catalyst by means of a molding device, and then drying and roasting the spherical or strip-shaped catalyst, wherein the mass percentages of components of the highly active and hydrothermally stable catalyst powder are: 0.02-20wt% of a covering component, 0.02-10wt% of doping metal, 0.02-10wt% of rare earth metal, and 60-99.4wt% of precursor. The highly active and hydrothermally stable catalyst has a specific surface area of 200-390 m2/g after treatment under high-temperature hydrothermal conditions, has high activity and hydrothermal stability, and is applicable to catalytic reactions under high-temperature hydrothermal process conditions.

Description

A kind of highly active hydrothermal stability catalyst and preparation method thereof

technical field

The invention relates to the field of catalysts, in particular to a high-activity, high-temperature, hydrothermally stable catalyst and a preparation method thereof.

Background technique

Catalysts are the soul of catalytic technology and the key core materials in the chemical industry. Porous materials are the most common catalytic materials, such as mesoporous molecular sieve catalysts, microporous molecular sieve catalysts, macroporous alumina catalysts, etc., because of their developed pore structure , high specific surface advantage, and high activity in the catalytic reaction process, so that it has broad application prospects in many fields. In general, the above-mentioned highly active catalytic materials have poor hydrothermal stability, and are particularly prone to skeleton collapse under high-temperature hydrothermal conditions (>800°C), resulting in the destruction of the entire material structure. The current high-activity catalytic materials have poor hydrothermal stability, which severely limits their application in high-temperature hydrothermal environments, especially for some catalytic reaction systems such as catalytic cracking with high temperature and the presence of water or water vapor. Therefore, how to improve the hydrothermal stability of catalytic materials under the premise of maintaining high activity has become one of the hot spots that people pay attention to.

CN108163869A discloses a method for improving the hydrothermal stability of silicon-based mesoporous materials. The silicon-based mesoporous materials and ionic liquids are placed in a closed reactor, and the reactor is heated and heat-insulated. Roasting at high temperature. The method of the invention uses environmentally friendly ionic liquids to carry out high-temperature secondary treatment on silicon-based mesoporous materials, and utilizes the dehydration and condensation of silicon hydroxyl groups on the surface of the pore walls of silicon-based mesoporous materials under the high temperature conditions of ionic liquids to improve the interaction of the pore walls. The joint degree increases the structural stability of the material, and then achieves the purpose of improving the hydrothermal stability of the silicon-based mesoporous material. After the SBA series silicon-based mesoporous material treated by the method of the invention is treated with 100% water vapor at 900° C. for 17 hours, the material can still maintain a good ordered mesoporous structure. CN109650422A discloses a method for improving the hydrothermal stability of mesoporous alumina materials. The three-block polymer template, aluminum source, inorganic acid, and solvent are mixed and stirred in a certain mass ratio, and the resulting slurry is left to stand for 12- After 48 hours, the obtained solid and ionic liquid were mixed according to ionic liquid and placed in a closed reaction kettle for treatment at 80-180°C. Then, it is filtered and dried, and finally calcined at a high temperature to obtain a mesoporous alumina material with high hydrothermal stability.

CN110817885A discloses a method for improving the hydrothermal stability of mesoporous silicon molecular sieves. Firstly, hydrothermal carbonization is used to load a hydrothermal carbon layer on the surface of mesoporous silicon molecular sieves, and then the hydrothermal stability is improved by high-temperature roasting. This method can not only significantly improve the hydrothermal stability of the mesoporous silicon molecular sieve, but also well maintain the mesoporous structure of the molecular sieve. The hydrothermal carbonization method is characterized in that an aminated molecular sieve is used as a carrier, biomass is used as a carbon source, water is used as a reaction medium, and a hydrothermal carbon layer is loaded on the surface of the mesoporous silicon molecular sieve. The method has the advantages of simple operation, convenience, low cost, wide application range and easy industrialization, and has broad application prospects in the fields of catalysis and the like.

CN104891525A discloses a method for preparing a strongly acidic and highly stable mesoporous molecular sieve. The preparation method first synthesizes the Y-type molecular sieve precursor, and then uses the seed crystal method to assemble the Y-type molecular sieve precursor under acidic conditions to obtain the first-step crystallization product, and finally adjusts the pH value of the first-step crystallization product to carry out the second step The product is obtained after crystallization. The mesoporous molecular sieve prepared by the invention shows excellent hydrothermal stability. After 800°C and 100% steam hydrothermal treatment, the specific surface area retention rate is more than 46%, and it has a good performance as a component of catalytic cracking catalyst for heavy oil. performance.

In the above-mentioned patents, the existing methods for improving hydrothermal stability include high-temperature treatment of ionic liquids, surface coating of carbon layers, and doping of aluminum atoms. Treatment of mesoporous silica, mesoporous alumina, and mesoporous molecular sieves can Significantly improve its hydrothermal stability. However, through ionic liquid surface treatment, carbonization layer coverage, in-situ crystallization and other treatments, the activity of the catalyst is greatly reduced. How to improve the hydrothermal stability of the catalytic material while maintaining high activity has become a major technical problem that needs to be solved at present.

Contents of the invention

The purpose of the present invention is to overcome the disadvantages of high activity and hydrothermal stability of catalysts in the prior art, and provide a catalyst with high activity and hydrothermal stability and a preparation method thereof.

The high-activity hydrothermal stability catalyst of the present invention adopts surface covering, metal doping, and rare earth modification methods to treat the catalyst precursor gel, improve the hydrothermal stability of the catalyst, and use transition metals and rare earth metals to increase catalyst metal active centers .

The present invention is specifically realized through the following technical solutions:

A high-activity hydrothermal-resistant and stable catalyst is prepared by mixing high-active hydrothermal-resistant and stable catalyst powder with a binder and a forming aid through molding equipment to prepare a spherical or strip-shaped catalyst, and then dried and roasted; wherein, The highly active hydrothermally stable catalyst powder is composed of covering components, doped metals, rare earth metals, and precursors. The covering components are 0.02 to 20 wt% based on the mass percentage of the total solid content of the catalyst powder, and the doped 0.02-10wt% for metals, 0.02-10wt% for rare earth metals, and 60-99.4wt% for precursors;

The covering component is one or more of ethyl orthosilicate, silicon tetrachloride, titanium tetrachloride, and n-butyl titanate;

The doping metal is one or more of manganese, tungsten, molybdenum, titanium, zirconium, germanium, tin and lead;

The rare earth metal is one or more of Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu;

The precursor is one or more of silicon-containing composite oxides, high-silicon molecular sieves, silicon dioxide, mesoporous silica, and mesoporous alumina;

The described highly active hydrothermally stable catalyst powder is prepared by the following preparation steps:

1) Surface coverage: the precursor is prepared by the sol-gel method. In the stage of the precursor gel, silicon/titanium is first used to cover the surface and pores, that is, the water in the precursor hydrogel is replaced with an alcohol solvent, and then the Alcohol solvent treatment containing covering components, and finally replacing the alcohol solvent with water and catalyzing the hydrolysis of the covering components to obtain a surface-covered precursor. The alcohol solvents are methanol, ethanol, propanol, isopropanol, butanol, One or more of ethylene glycol;

2) Metal doping: Add soluble doped metal salt-inorganic acid solution to the surface-covered precursor during the gel generation process or gel aging stage, so that the doped metal is bonded to the silicon-aluminum precursor skeleton, and then washed with water to remove Unreacted soluble doping metal salt and inorganic acid to obtain metal doping precursor;

3) Rare earth modification: introducing a rare earth metal salt into the metal-doped precursor by ion exchange, impregnation or coprecipitation to obtain a rare earth modified precursor;

4) Drying, calcining and pulverizing the rare earth modified precursor to obtain a highly active hydrothermally stable catalyst powder.

In the technical solution of the highly active hydrothermally stable catalyst described in the present invention, the silicon-containing composite oxide is one or more of silicon-aluminum composite oxide, silicon-magnesium composite oxide, and silicon-titanium composite oxide.

The high-silicon molecular sieve is a high-silicon Y molecular sieve with a SiO ₂ /Al ₂ O ₃ molar ratio greater than 5.0, a β molecular sieve with a SiO ₂ /Al ₂ O ₃ molar ratio greater than 40, or a SiO ₂ /Al ₂ O ₃ molar ratio greater than 60 One or more of ZSM-5 molecular sieves.

The mesoporous silica is one or more of MCM-41 and SBA-15.

The present invention also provides a preparation method of the above-mentioned highly active hydrothermally stable catalyst, the preparation method comprising the following steps:

1) Surface coverage: the precursor is covered with silicon/titanium on the surface and pores in the gel stage. The steps include first replacing the water in the precursor hydrogel with an alcohol solvent, and then using an alcohol containing the covering component. Solvent treatment, and finally replace the alcohol solvent with water and catalyze the hydrolysis of the covering component to obtain a surface-covered precursor. The alcohol solvent is one of methanol, ethanol, propanol, isopropanol, butanol, and ethylene glycol or several;

2) Metal doping: After the surface of the precursor is covered, add a soluble doped metal salt-inorganic acid solution during the gel generation process or the gel aging stage, so that the doped metal is bonded to the silicon-aluminum precursor skeleton, and then washed with water to remove Unreacted soluble doping metal salt and inorganic acid to obtain metal doping precursor;

3) Rare earth modification: the rare earth metal salt is introduced into the metal-doped precursor by ion exchange, impregnation, and coprecipitation to obtain a rare earth modified precursor;

4) drying and roasting the rare earth modified precursor to obtain a highly active hydrothermally stable catalyst powder;

5) The highly active hydrothermally stable catalyst powder is mixed with a binder and a molding aid to prepare a spherical or strip-shaped catalyst through a molding device, and then dried and roasted to obtain a highly active hydrothermally stable catalyst.

In the preparation method of the present invention, preferably, the doping metal of the soluble doping metal salt-inorganic acid is one or more of manganese, tungsten, molybdenum, titanium, zirconium, germanium, tin, and lead;

The rare earth metal salt is one or more soluble metal salts of Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu .

In the preparation method of the present invention, it is further preferred that the soluble doped metal salt-inorganic acid is a manganese nitrate dilute sulfuric acid solution with a concentration of 0.15-0.25 mol/L.

In the preparation method of the present invention, it is further preferred that the rare earth metal salt described in step 4) is cerium nitrate, the calcination is at 350-700° C., and the calcination time is 4-24 hours.

The present invention further provides the application of the above-mentioned highly active hydrothermal stability catalyst in the catalytic reaction under the high temperature hydrothermal process condition of 500-850°C.

Further preferably, the application of the high-activity hydrothermal-resistant and stable catalyst of the present invention in heavy oil catalytic cracking reaction under high-temperature hydrothermal process conditions, the conversion rate of heavy oil is greater than 80wt%, the selectivity of low-carbon olefins is greater than 80%, and the coke yield is less than 10wt% .

Highly active, water-resistant and thermally stable catalysts can be molded by spray drying, rolling ball molding, extrusion molding, and powerful granulation.

The highly active hydrothermally stable catalyst used for fluidized catalytic cracking reaction is a microspherical catalyst with a particle size distribution of 20-200 μm. The molding method is spray drying. It is 90-280°C.

The highly active hydrothermally stable catalyst of the present invention has relatively high pore wall thickness, and has good hydrothermal stability in a high-temperature hydrothermal environment. The catalyst also has a skeleton-doped metal, which forms a bond with the skeleton elements such as silicon and aluminum in the carrier through the doping of the metal skeleton. The metal doping can slow down the damage of the skeleton elements by water vapor under high-temperature hydrothermal conditions, and can also generate defects. position, has catalytic activity, and further improves the hydrothermal stability and catalytic activity of the catalyst. Finally, rare earth metals are introduced to further protect the doping metals and catalyst skeleton elements, and improve the activity and stability of the catalyst again.

The surface and pores of the catalyst carrier are covered with silicon/titanium, which increases the wall thickness of the carrier pores and improves the hydrothermal stability of the catalyst. Afterwards, the transition metal skeleton is doped and the rare earth metal is loaded to further improve the hydrothermal stability. The specific surface area of the catalyst powder is maintained at 100-390m ² /g when the catalyst powder is treated under the hydrothermal condition of 800°C for a long time, and the high-temperature hydrothermal stability is very excellent.

Compared with existing catalysts at present, the highly active hydrothermal stability catalyst prepared by the present invention has the following advantages:

(1) Excellent high-temperature hydrothermal stability: The catalyst carrier has undergone pore wall thickness, transition metal skeleton doping and rare earth metal loading, and the hydrothermal stability has been greatly improved. The surface area reaches up to 390m ² /g, and the molded catalyst is treated under hydrothermal conditions at 800°C for a long time, and the specific surface area reaches up to 250m ² /g

(2) Highly active catalytic performance: the catalyst is doped with transition metal skeleton and rare earth metal, and the transition metal doped with skeleton is used to generate defect center to form a highly active catalytic center, and the rare earth metal loading further improves the activity and stability of the catalyst. In the catalytic cracking reaction of heavy oil under hydrothermal conditions, the conversion rate of heavy oil is greater than 80wt%, and the catalyst has high activity. The catalyst with high activity and high hydrothermal stability is especially suitable for the catalytic cracking reaction process of heavy oil such as residue oil and oil sand bitumen under high temperature hydrothermal environment. The olefin selectivity is greater than 80%, the coke yield is less than 10wt%, and has high activity and hydrothermal stability.

Detailed ways

The implementation of the highly active hydrothermally stable catalyst and the preparation method of the present invention will be described in detail below through specific comparative examples and examples, but not limited to the examples.

The invention adopts surface covering, metal doping and rare earth modification methods to treat the catalyst precursor gel to improve the hydrothermal stability of the catalyst, and utilizes transition metals and rare earth metals to increase catalyst metal active centers, surface covering and metal doping 1. The method of rare earth modification can be impregnation method, washing replacement method, ion exchange method, co-precipitation method, or other metal loading and modification methods.

The inventors found that after screening titanium/silicon covering components, transition metals, and rare earth metals, covering the carrier with silicon/titanium, doping the transition metal skeleton, and loading rare earth metals, the hydrothermal stability and activity of the catalyst can be effectively improved. , has high hydrothermal stability at 500-850°C, is suitable for catalytic reactions under high-temperature hydrothermal conditions, and is more suitable for catalytic cracking reactions of heavy oils such as residual oil and oil sand bitumen.

The catalyst performance evaluation method of high activity hydrothermal stability of the present invention is as follows:

A fluidized bed pilot plant was used to evaluate the highly active hydrothermally stable catalyst. The properties of the heavy oil raw material used are shown in Table 1.

The catalyst used for the catalytic cracking performance reaction of heavy oil is pre-aged at 800°C and 100% water vapor for 24 hours. The samples before and after hydrothermal treatment are used to measure the BET specific surface area and pore volume by nitrogen adsorption, and the specific surface area and pore volume after hydrothermal treatment are calculated. See Table 2 for relevant data.

Performance evaluation of highly active hydrothermally stable catalysts was carried out on a fluidized bed pilot plant. Process conditions: reaction pressure 0.2MPa, reaction temperature 550°C, steam/feedstock oil weight ratio 0.3:1, agent-oil ratio 12:1, The contact time is 2s. The collected gas phase products were measured by refinery gas chromatography, the liquid products were measured by true boiling point distillation, and the liquid product family composition was determined by chromatography-mass spectrometry. The product analysis data of each embodiment are shown in Table 3.

Among them, the calculation formula of heavy oil conversion rate is as follows:

The inventive process is illustrated by examples below, but not limited to these examples.

comparative example

(1) Mesoporous silica hydrogel was selected as the precursor, and the precursor was dried at 120°C for 12 hours, and then crushed to obtain a comparative catalyst powder: the measured BET specific surface area was 687m ² /g, and the pore volume was 0.71cm ³ /g, the mesoporous silica powder is subjected to hydrothermal aging treatment first, and first undergoes 800°C, 100% water vapor aging treatment for 24 hours, then tests the specific surface area and pore volume of the catalyst after hydrothermal treatment, and calculates the specific surface area after hydrothermal treatment and pore volume retention rate, the relevant data are shown in Table 2.

(2) Pulverize the mesoporous silica, add kaolin, aluminum sol, water, and stir to prepare a slurry. The solid content of the slurry is controlled within 20%. The slurry is stirred and beaten for 6 hours, and the proportion of mesoporous silica in the solid compound is 40wt%. , the kaolin is 40wt%, and the alumina in the aluminum sol is 20wt%.

(3) The slurry after beating is spray-dried into 40-150um microspheres, and the inlet temperature of the spray drying tower is controlled at 450°C, and the outlet temperature is 110°C.

(4) The obtained microsphere catalyst was sprayed, dried at 120° C. for 12 hours, and calcined at 650° C. for 4 hours to obtain a comparative catalyst.

(5) Catalyst evaluation and product analysis: The raw material of the evaluation catalyst is , and the specific analysis data are shown in Table 1. The catalyst has been aged at 800°C and 100% water vapor for 24 hours in advance, simulating the high temperature hydrothermal conditions of industrial equipment. After hydrothermal treatment, catalyst reaction performance evaluation was carried out on a fluidized bed pilot plant. Process conditions: reaction pressure 0.2MPa, temperature 550°C, steam/raw material oil weight ratio 0.3:1, agent-oil ratio 12:1, contact time 2s The collected gas phase products are measured by refinery gas chromatography, the liquid products are measured by true boiling point distillation, and the liquid product family composition is determined by chromatography-mass spectrometry. The product analysis data of each embodiment are shown in Table 3.

Example 1

(1) The highly active hydrothermally stable catalyst powder is composed of covering components, doping metals, rare earth metals, and precursors. In terms of the mass percentage of the total solid content of the catalyst, the covering components are 0.77wt%, and the doping metals are 0.86 wt%, the rare earth metal is 0.25wt%, and the remaining components are precursors, and the precursors are mesoporous silicon dioxide.

(2) Precursor surface coverage: use mesoporous silica hydrogel 1000g (mesoporous silica hydrogel is the same as the comparative example), the solid content of silica in the gel is 15wt%, and the remaining components are water. First replace the water in the mesoporous silica gel with ethanol solvent, then treat with ethanol solvent with n-butyl titanate concentration of 0.1wt%, consume 5000g of solvent, and finally replace alcohol solvent with water and catalyze the hydrolysis of n-butyl titanate , to obtain a surface-covered precursor, wherein the mass of the covering component is 1.18 g (calculated by the mass of titanium dioxide), and the mass of the precursor is 150 g (calculated by the mass of silica).

(3) Doping with transition metals: prepare manganese nitrate dilute sulfuric acid solution, the mass fraction of manganese nitrate is 0.25wt%, the pH value of the solution is 2, impregnate the surface-covered precursor of step (2) with 2000g manganese nitrate dilute sulfuric acid solution, impregnate The temperature was 60°C, and the immersion time was 12 hours. After immersion, it was washed with deionized water until neutral to obtain a transition metal-doped precursor, and the mass of the transition metal-doped manganese oxide was detected to be 1.31 g.

(4) Rare earth modification: prepare rare earth modified precursor by ion exchange method, prepare 5000g cerium nitrate concentration as 0.15wt% cerium nitrate solution, contact with the transition metal doped precursor of step (3) at 80°C, After the cerium nitrate solution was circulated for 12 hours, it was washed with deionized water to obtain a rare earth modified precursor, and the mass of the rare earth metal cerium oxide was detected to be 0.38 g.

(5) The rare earth modified precursor prepared in step (4) was dried at 120° C. for 12 hours, then calcined at 550° C. for 4 hours, and pulverized to obtain a highly active hydrothermally stable catalyst powder. The powder is subjected to hydrothermal aging treatment first, and the treatment conditions are the same as those of the comparative example. The specific surface area and pore volume retention rate after hydrothermal treatment are calculated. The relevant data are shown in Table 2.

(6) The spray molding of the catalyst is the same as that of the comparative example, and the drying and calcination conditions are the same as those of the comparative example.

(7) Catalyst evaluation and product analysis are the same as those of the comparative example.

Example 2

(1) High-silicon ZSM-5 molecular sieve hydrogel is selected. The physical properties of the molecular sieve are that the molar ratio of SiO ₂ to Al ₂ O ₃ is 92, the content of sodium oxide is 0.02wt%, the BET specific surface area is 347m ² /g, and the pore volume 0.30 cm ³ /g.

(2) The highly active hydrothermally stable catalyst powder is composed of covering components, doping metals, rare earth metals, and precursors. In terms of the mass percentage of the total solid content of the catalyst, the covering components are 1.01wt%, and the doping metals are 0.76 wt%, the rare earth metal is 0.28wt%, and the remaining components are precursors.

(3) Precursor surface coverage: use high silicon ZSM-5 molecular sieve hydrogel 1000g, the solid content of silicon dioxide in the gel is 22wt%, and the rest is water, first use the moisture in the high silicon ZSM-5 molecular sieve gel as ethanol solvent , treated with an ethanol solvent with a n-butyl titanate concentration of 0.2wt%, consuming 5000 g of solvent, and finally replacing the alcohol solvent with water and catalyzing the hydrolysis of n-butyl titanate to obtain a surface-covered precursor. The mass of the covered component was detected as 2.28g (based on the mass of titanium dioxide), and the mass of the precursor is 220g (based on the total mass of silica and alumina).

(4) Doping with transition metals: prepare manganese nitrate dilute sulfuric acid solution, the mass fraction of manganese nitrate is 0.35wt%, the pH value of the solution is 3.5, impregnate the surface-covered precursor of step (3) with 2000g manganese nitrate dilute sulfuric acid solution, impregnate The temperature was 60°C, and the immersion time was 12 hours. After immersion, it was washed with deionized water until neutral to obtain a transition metal-doped precursor, and the mass of transition metal-doped manganese oxide was detected to be 1.72 g.

(5) Rare earth modification: prepare rare earth modified precursor by ion exchange method, prepare 5000g of cerium nitrate concentration as 0.15wt% cerium nitrate solution, contact with the transition metal doped precursor of step (4) at 80°C, After the cerium nitrate solution was circulated for 12 hours, it was washed with deionized water to obtain a rare earth modified precursor, and the mass of the rare earth metal cerium oxide was detected to be 0.64 g.

(6) The rare earth modified precursor prepared in step (5) was dried at 120° C. for 12 hours, then calcined at 550° C. for 4 hours, and pulverized to obtain a highly active hydrothermally stable catalyst powder. The powder is subjected to hydrothermal aging treatment first, and the treatment conditions are the same as those of the comparative example. The specific surface area and pore volume retention rate after hydrothermal treatment are calculated. The relevant data are shown in Table 2.

(7) The spray molding of the catalyst is the same as that of the comparative example, and the drying and calcination conditions are the same as those of the comparative example.

(8) Catalyst evaluation and product analysis are the same as those of the comparative example.

Example 3

(1) Select silicon-aluminum composite oxide hydrogel, the physical properties of silicon-aluminum composite oxide are SiO ₂ content 84.15wt%, Al2O3 content 15.62wt%, sodium oxide content 0.23wt%, BET specific surface area 315m ² /g, pores Capacity 0.57cm ³ /g.

(2) The highly active hydrothermally stable catalyst powder is composed of covering components, doped metals, rare earth metals, and precursors. In terms of the mass percentage of the total solid content of the catalyst, the covering components are 1.59 wt%, and the doping metals are 0.91 wt%. wt%, the rare earth metal is 0.40wt%, and the remaining components are precursors.

(3) Precursor surface coverage: use 1000g of silicon-aluminum composite oxide hydrogel, the solid content of silicon dioxide in the gel is 18wt%, and the rest is water. First, replace the moisture in the silicon-aluminum composite oxide gel with ethanol solvent, Treat with an ethanol solvent with a n-butyl titanate concentration of 0.25wt%, consume 5000g of solvent, and finally replace the alcohol solvent with water and catalyze the hydrolysis of n-butyl titanate to obtain a surface-covered precursor. The mass of the covered component was detected to be 2.86 g (based on the mass of titanium dioxide), and the mass of the precursor is 180 g (based on the sum of the mass of silica and alumina).

(4) Doping with transition metals: prepare manganese nitrate dilute sulfuric acid solution, the mass fraction of manganese nitrate is 0.32wt%, the pH value of the solution is 2, impregnate the surface-covered precursor of step (3) with 2000g manganese nitrate dilute sulfuric acid solution, impregnate The temperature was 60°C, and the immersion time was 12 hours. After immersion, it was washed with deionized water until neutral to obtain a transition metal-doped precursor, and the mass of the transition metal-doped manganese oxide was detected to be 1.68 g.

(5) Rare earth modification: Prepare rare earth modified precursor by ion exchange method, prepare 5000g cerium nitrate concentration as 0.20wt% cerium nitrate solution, contact with the transition metal doped precursor of step (4) at 80°C, After the cerium nitrate solution was circulated for 12 hours, it was washed with deionized water to obtain a rare earth modified precursor, and the mass of the rare earth metal cerium oxide was detected to be 0.72 g.

Example 4

(1) SiO2 is selected as the precursor, the SiO2 content is 99.8wt%, the sodium oxide content is 0.2wt%, the BET specific surface area is 663m2/g, and the pore volume is 0.74cm3/g.

(2) The highly active hydrothermally stable catalyst powder is composed of covering components, doping metals, rare earth metals, and precursors. In terms of the mass percentage of the total solid content of the catalyst, the covering components are 2.34wt%, and the doping metals are 0.84 wt%, the rare earth metal is 0.33wt%, and the remaining components are precursors.

(3) Precursor surface coverage: use 1000g of silica hydrogel, the solid content of silica in the gel is 17wt%, the rest is water, first replace the moisture in the silica gel with ethanol solvent, and The butyl ester concentration is 0.35wt% ethanol solvent treatment, consumes 5000g of solvent, finally replaces alcoholic solvent with water and catalyzes the hydrolysis of n-butyl titanate, obtains the precursor of surface coverage, detects that the mass of covering component is 4.08g (as titanium dioxide mass), the mass of the precursor is 170g (based on the total mass of silica and alumina).

(4) Doping with transition metals: prepare manganese nitrate dilute sulfuric acid solution, the mass fraction of manganese nitrate is 0.26wt%, the pH value of the solution is 2.5, impregnate the surface-covered precursor of step (3) with 2000g manganese nitrate dilute sulfuric acid solution, impregnate The temperature was 60°C, and the immersion time was 12 hours. After immersion, it was washed with deionized water until neutral to obtain a transition metal-doped precursor, and the mass of the transition metal-doped manganese oxide was detected to be 1.48 g.

(5) Rare earth modification: Prepare rare earth modified precursor by ion exchange method, prepare 5000g cerium nitrate concentration as 0.25wt% cerium nitrate solution, contact with the transition metal doped precursor of step (4) at 80°C, After circulating the cerium nitrate solution for 12 hours, it was washed with deionized water to obtain a rare earth modified precursor, and the mass of the rare earth metal cerium oxide was detected to be 0.58 g.

Example 5

(1) Selecting the precursor is the same as in Example 2.

(2) The highly active hydrothermally stable catalyst powder is composed of covering components, doped metals, rare earth metals, and precursors. In terms of the mass percentage of the total solid content of the catalyst, the covering components are 1.01 wt%, and the doping metals are 0.61 wt%. wt%, the rare earth metal is 0.28wt%, and the remaining components are precursors.

(3) Precursor surface coverage is the same as in Example 2.

(4) Doping with transition metals: prepare manganese nitrate dilute sulfuric acid solution, the mass fraction of manganese nitrate is 0.26wt%, the pH value of the solution is 2.5, impregnate the surface-covered precursor of step (3) with 2000g manganese nitrate dilute sulfuric acid solution, impregnate The temperature was 60°C, and the immersion time was 12 hours. After immersion, it was washed with deionized water until neutral to obtain a transition metal-doped precursor, and the mass of the transition metal-doped manganese oxide was detected to be 1.36 g.

(5) Rare earth modification is the same as in Example 2.

Example 6

(1) Selecting the precursor is the same as in Example 2.

(2) The highly active hydrothermally stable catalyst powder is composed of covering components, doping metals, rare earth metals, and precursors. In terms of the mass percentage of the total solid content of the catalyst, the covering components are 1.01wt%, and the doping metals are 1.53 wt%, the rare earth metal is 0.28wt%, and the remaining components are precursors.

(3) Precursor surface coverage is the same as in Example 2.

(4) Doping with transition metals: prepare dilute zirconium nitrate sulfuric acid solution, the mass fraction of zirconium nitrate is 0.71wt%, the pH value of the solution is 2.1, impregnate the surface-covered precursor of step (3) with 2000g dilute zirconium nitrate sulfuric acid solution, impregnate The temperature was 60°C, and the immersion time was 12 hours. After immersion, it was washed with deionized water until neutral to obtain a transition metal-doped precursor, and the mass of transition metal-doped zirconia was detected to be 3.41 g.

(5) Rare earth modification is the same as in Example 2.

The basic properties of raw materials used in the embodiment of table 1

Table 2 BET data table of catalyst before and after hydrothermal treatment

Table 3 Catalyst performance evaluation data table

Claims

A highly active hydrothermally stable catalyst, characterized in that the highly active hydrothermally stable catalyst powder is mixed with a binder and a molding aid to prepare a spherical or bar-shaped catalyst through molding equipment, and then dried and calcined to produce have to;

Wherein, the highly active hydrothermally stable catalyst powder is composed of coating components, doped metals, rare earth metals, and precursors, and the mass percentage of each component is: the coating component is 0.02 to 20 wt%, and the doped 0.02-10wt% for metals, 0.02-10wt% for rare earth metals, and 60-99.4wt% for precursors;

The covering component is one or more of ethyl orthosilicate, silicon tetrachloride, titanium tetrachloride, and n-butyl titanate;

The doping metal is one or more of manganese, tungsten, molybdenum, titanium, zirconium, germanium, tin and lead;

The rare earth metal is one or more of Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu;

The precursor is one or more of silicon-containing composite oxides, high-silicon molecular sieves, silicon dioxide, mesoporous silica, and mesoporous alumina;

The described highly active hydrothermally stable catalyst powder is prepared by the following preparation steps:

1) Surface coverage: the precursor is prepared by a sol-gel method. In the gel stage, the precursor first replaces the water in the precursor hydrogel with an alcohol solvent, and then treats it with an alcohol solvent containing a covering component, and finally replacing the alcoholic solvent with water and catalyzing the hydrolysis of the covering component to obtain a surface-covered precursor, the alcoholic solvent being one or more of methanol, ethanol, propanol, isopropanol, butanol, and ethylene glycol;

2) Metal doping: Add soluble doped metal salt-inorganic acid solution to the surface-covered precursor during the gel generation process or gel aging stage, so that the doped metal is bonded to the silicon-aluminum precursor skeleton, and then washed with water to remove Unreacted soluble doping metal salt and inorganic acid to obtain metal doping precursor;

3) Rare earth modification: introducing a rare earth metal salt into the metal-doped precursor by ion exchange, impregnation or coprecipitation to obtain a rare earth modified precursor;

4) Drying, calcining and pulverizing the rare earth modified precursor to obtain a highly active hydrothermally stable catalyst powder.
The highly active hydrothermally stable catalyst according to claim 1, wherein the silicon-containing composite oxide is one or more of silicon-aluminum composite oxides, silicon-magnesium composite oxides, and silicon-titanium composite oxides. kind.
The highly active hydrothermally stable catalyst according to claim 1, characterized in that, the high-silicon molecular sieve is a high-silicon Y molecular sieve with a molar ratio of SiO 2 /Al 2 O 3 greater than 5.0, SiO 2 /Al 2 O 3 One or more of β molecular sieves with a molar ratio greater than 40 or ZSM-5 molecular sieves with a SiO 2 /Al 2 O 3 molar ratio greater than 60.
The highly active hydrothermally stable catalyst according to claim 1, characterized in that the mesoporous silica is one or more of MCM-41 and SBA-15.
A preparation method of the highly active hydrothermally stable catalyst according to claim 1, characterized in that, comprising the steps of:

1) Surface coverage: In the gel stage of the precursor, the precursor is first replaced with an alcohol solvent for the water in the precursor hydrogel, then treated with an alcohol solvent containing the covering component, and finally the water is used to replace the alcohol solvent and catalytic coverage The components are hydrolyzed to obtain a surface-covered precursor, and the alcohol solvent is one or more of methanol, ethanol, propanol, isopropanol, butanol, and ethylene glycol;

2) Metal doping: Add soluble doping metal salt-inorganic acid solution to the precursor after surface covering during the gel generation process or gel aging stage, so that the doping metal is bonded to the silicon-aluminum precursor skeleton, and then washed with water Removing unreacted soluble doping metal salts and inorganic acids to obtain metal doping precursors;

3) Rare earth modification: the rare earth metal salt is introduced into the metal-doped precursor by ion exchange, impregnation, and coprecipitation to obtain a rare earth modified precursor;

4) Drying and roasting the rare earth modified precursor to obtain a highly active hydrothermally stable catalyst powder;

5) The highly active hydrothermally stable catalyst powder is mixed with a binder and a molding aid to prepare a spherical or strip-shaped catalyst through a molding device, and then dried and roasted to obtain a highly active hydrothermally stable catalyst.
The method for preparing a highly active hydrothermally stable catalyst according to claim 5, wherein the soluble doped metal salt-inorganic acid is a manganese nitrate dilute sulfuric acid solution with a concentration of 0.15-0.25 mol/L.
The preparation method of the highly active hydrothermally stable catalyst according to claim 5, characterized in that the rare earth metal salt described in step 4) is cerium nitrate, the calcination is 350-700°C, and the calcination time is 4 ~24 hours.
An application of the highly active hydrothermally resistant and stable catalyst according to claim 1 in catalytic reactions under high temperature hydrothermal process conditions of 500-850°C.
A kind of application according to claim 8, is characterized in that, described catalytic reaction is heavy oil catalytic cracking reaction, and heavy oil conversion rate is greater than 80wt%, light olefin selectivity is greater than 80%, coke yield is less than 10wt%.