Catalytic cracking catalyst carrier as well as preparation method and application thereof

Abstract

The invention discloses a catalytic cracking catalyst carrier and a preparation method and application thereof, and relates to the technical field of petrochemical engineering, the preparation method comprises the following steps: adding pseudo-boehmite into deionized water, uniformly stirring, then adding a nitric acid solution, and stirring to obtain gel; adding pseudo-boehmite and deionized water into the gel, stirring for peptization, heating and uniformly stirring to obtain sol; adding a silicon-aluminum material, deionized water and modified cellulose into the sol, mixing and pulping, and carrying out spray forming and drying to obtain microspheres; and roasting the microspheres to obtain the catalytic cracking catalyst carrier, the carrier has relatively large pore volume and specific surface area, also has excellent wear-resistant property, can keep the structure stable for a long time at high temperature, can tolerate the temperature and hydrothermal conditions of catalytic cracking reaction, can maintain the carbon containing performance of the carrier in the thermal conversion process for a long time, and can effectively improve the yield of low-carbon olefin.

Description

Technical Field

[0001] The present invention relates to the technical field of petrochemical industry, and particularly relates to a catalytic cracking catalyst carrier, a preparation method thereof and an application thereof. Background Art

[0002] As important organic chemical raw materials, light olefins such as ethylene and propylene play an irreplaceable role in the national economy. With the rapid development of the economy, the market demands for ethylene and propylene in China have been in a rapid growth trend for a long time. At present, the sources of ethylene, propylene and butene are classified into two technical directions of catalytic conversion and thermal cracking from the generation mechanism. The thermal cracking method is a direct thermal cracking process represented by the tubular cracking furnace process, and its characteristic is that the raw material conversion is mainly based on free radical thermal cracking reaction, and ethylene is the main target product. The catalytic conversion method is a catalytic conversion process represented by the catalytic cracking process, and its characteristic is that the raw material undergoes a catalytic cracking reaction on an acid catalyst based on the carbocation mechanism, usually with gasoline and diesel as the target products, and the by-produced light olefins are mainly propylene.

[0003] The tubular furnace cracking method accounts for more than half of the world's ethylene production. This method is generally applicable to light hydrocarbon raw materials such as naphtha, light diesel, ethane, propane, butane, etc., and is not suitable for processing heavy oil products with a serious coking tendency.

[0004] FCC (including conventional FCC, DCC, etc.) units are important units for heavy oil lightening. During the production of gasoline and diesel, by-produced C2, C3 and C4 olefins are generated. Compared with olefin production processes such as ethylene cracking furnaces, the olefin selectivity and yield of FCC are both relatively low. The catalytic thermal cracking process (CN00105235.7) is a proprietary technology for producing light olefins from heavy oil by the Petroleum Science Research Institute, which uses a special catalyst containing molecular sieve to produce light olefins with the goal of maximizing propylene. The heavy oil direct cracking to ethylene HCC (CN92105507.2) is a proprietary technology for producing ethylene from heavy oil by Luoyang Petrochemical Engineering Corporation. It is a fluidized cracking technology following the free radical mechanism, which uses solid particle contact agents with certain catalytic activity to promote free radical reactions. The contact agents are rapidly contacted with heavy oil raw materials in the riser reactor to obtain light olefins mainly composed of ethylene. Its catalyst uses a mixture of silica and alumina as the main component of the contact agent.

[0005] The conversion step of heavy oil pyrolysis to olefins is a strongly endothermic free radical cracking reaction process, usually carried out under high temperature reaction conditions of 600 - 850°C. In the riser or fluidized bed process of heavy oil pyrolysis to olefins with continuous reaction and regeneration, the coke by-produced during the cracking reaction process enters the regenerator with the deactivated catalyst from the settler. During the coke burning process in the regenerator, the temperature of the catalyst is raised to 750 - 950°C. The regenerated high-temperature catalyst then enters the riser reactor to contact the reaction raw materials and provides the reaction heat at the same time. Obviously, the heat required for the reaction is provided by the combustion heat of coke. If the coke yield is too low, insufficient heat can be provided during the coke burning in the regenerator to meet the reaction temperature, and additional fuel needs to be injected into the regenerator to supplement the heat. In actual situations, for the high-temperature thermal cracking of heavy oil to pursue the maximum yield of low-carbon olefins, the reaction depth is relatively deep, and the coke yield often reaches as high as 10 - 20%. The heat generated by its combustion can fully meet the process requirements. However, if the catalyst or contact agent does not have a high enough carbon-loading capacity, the coke generated by the reaction will deposit in the form of coke powder in the settler or enter the subsequent oil-gas system, not only causing blockage of the settler and the oil-gas system, but also deteriorating the properties of heavy oil. The inability of the catalyst or contact agent to effectively load carbon will also result in insufficient coke available for burning in the regenerator, unable to reach the target temperature for coke burning and regeneration, and thus additional fuel has to be injected into the regenerator to supplement the heat.

[0006] For the catalyst or contact agent to be able to better accommodate carbon, it must have a larger pore volume and specific surface area, so that the generated coke can adhere to the catalyst and the generated coke can be carried into the regenerator by the catalyst or contact agent. In the riser or fluidized bed process of heavy oil pyrolysis to olefins with continuous reaction and regeneration, common catalytic materials with large pore volume and specific surface area cannot withstand the hydrothermal environment at 750 - 950°C in the regenerator for a long time, which will inevitably cause the pore volume and specific surface area of the catalyst or contact agent to rapidly decrease with the service time. Therefore, it is required that the catalyst must have good temperature and hydrothermal resistance while having a large pore volume and specific surface area, so that its structure can be stable at a temperature of 800 - 950°C for a long time, thereby maintaining its carbon-loading performance for a long time.

[0007] Therefore, while ensuring the high hydrothermal stability of the catalyst or contact agent, maximizing the carbon-loading amount on the catalyst or contact agent during the thermal conversion process is the guarantee for the heavy oil direct conversion process to produce low-carbon olefins to obtain a stable operating state and the best economic benefits.

[0008] Among the known carrier materials, the SiO2 material has poor strength, is not impact-resistant, undergoes high-temperature transformation, and is not suitable for continuous reaction-regeneration fluidized beds and high-temperature processes. Among molecular sieve materials, Y-type molecular sieves are not heat-resistant, and ZSM-5 molecular sieves have a relatively small pore size and are not suitable for the cracking of heavy oil macromolecules. The above materials cannot meet the relatively harsh operating conditions for heavy oil cracking to produce olefins, and it is necessary to develop a special catalyst heat carrier to achieve the smooth operation of a device for directly converting heavy oil to produce low-carbon olefins.

[0009] Chinese patent document CN202110441783.7 discloses an application of a contact agent, a modified contact agent, and its preparation method and application. The main components of the contact agent include at least one of θ-Al2O3, δ-Al2O3, and η-Al2O3. The components of the modified contact agent include the contact agent and alkali metal oxides and / or alkaline earth metal oxides supported on the surface of the contact agent. The content of Al2O3 in the modified contact agent is 60-100 wt%, and the total amount of alkali metal oxides and / or alkaline earth metal oxides in the modified contact agent does not exceed 15 wt%; the pore volume and wear resistance of the contact agent can be further improved. Summary of the Invention

[0010] In order to solve the deficiencies of the existing technology, the purpose of the present invention is to provide a catalytic cracking catalyst carrier, its preparation method and application. The carrier has a large pore volume and specific surface area, and at the same time has excellent wear resistance, can maintain a stable structure for a long time at high temperature, can withstand the temperature and hydrothermal conditions of the heavy oil cracking to produce low-carbon olefins reaction, maintain the carbon capacity of the carrier during the long-term thermal conversion process, and can effectively improve the yield of low-carbon olefins.

[0011] To achieve the above purpose, the present invention adopts the following technical solutions:

[0012] A preparation method of a catalytic cracking catalyst carrier includes the following steps:

[0013] Add pseudoboehmite to deionized water, stir evenly, then add nitric acid solution and stir to obtain a gel; add pseudoboehmite and deionized water to the gel, stir to perform peptization, heat and stir evenly to obtain a sol; add silica-alumina material, deionized water, and modified cellulose to the sol, mix and beat to form a slurry, and obtain microspheres through spray forming and drying; calcine the microspheres to obtain the catalytic cracking catalyst carrier.

[0014] Preferably, when preparing the gel, the weight ratio of pseudoboehmite, deionized water, and nitric acid solution is 0.2-0.5:1:0.03-0.05; the concentration of the nitric acid solution is 60-68 wt%.

[0015] Preferably, when preparing the sol, the weight ratio of pseudoboehmite to deionized water is 0.05-0.13:1.

[0016] Preferably, when preparing the sol, the weight ratio of pseudo-boehmite to gel is 0.03-0.08:1.

[0017] Preferably, when preparing the sol, the heating and stirring conditions are stirring and heating at 60-100° C. for 5-12 hours.

[0018] Preferably, when preparing microspheres, the weight ratio of the silicon-aluminum material, deionized water, and modified cellulose is 0.6-1: 1-1.5: 0.01-0.1.

[0019] Preferably, when preparing microspheres, the weight ratio of the silicon-aluminum material to the sol is 0.05-0.2:1.

[0020] Preferably, when preparing microspheres, the particle size of the microspheres is 50 to 150 μm.

[0021] Preferably, the calcination condition is 750-1100° C. for 3-6 hours.

[0022] Preferably, when preparing microspheres, the silicon-aluminum material is one or more of pseudo-boehmite, diaspore, and clay.

[0023] Preferably, the method for preparing the modified cellulose comprises the following steps:

[0024] (1) dissolving carboxymethyl cellulose in deionized water, then adding periodic acid solution, adjusting the pH of the system, stirring the reaction, precipitating the reaction solution with acetone, filtering, washing, drying, and crushing the product to obtain oxidized cellulose;

[0025] (2) dissolving oxidized cellulose in deionized water, then adding diethylenetriamine dropwise under stirring, stirring for reaction, filtering, washing, and drying the product to obtain Schiff-alkalized cellulose containing imine bonds;

[0026] (3) Dispersing the Schiff alkalized cellulose in DMF, stirring and dispersing the cellulose uniformly, then adding diethyl phosphite, heating the cellulose under microwave reflux, filtering the cellulose, recrystallizing the cellulose with propanol, washing the cellulose, and vacuum drying the cellulose to obtain modified cellulose.

[0027] Preferably, in step (1), the weight volume ratio of carboxymethyl cellulose to deionized water is 1 g: 10-20 mL, the concentration of the periodic acid solution is 5-10 wt %, and the weight ratio of carboxymethyl cellulose to the periodic acid solution is 1: 0.8-1; the pH of the system is adjusted to 1.5-4, and the stirring reaction conditions are 25-45° C. for 4-10 hours.

[0028] Preferably, in step (2), the weight-volume ratio of oxidized cellulose to deionized water is 1 g: 30-40 mL; the weight ratio of oxidized cellulose to diethylenetriamine is 1: 1.56-2.74; the stirring reaction conditions are reaction at 50-60 °C for 8-12 h.

[0029] Preferably, in step (3), the weight ratio of Schiff base cellulose to diethyl phosphite is 1: 1.9-3.3, the microwave heating power is 400-500 W, and the reflux reaction time is 2-4 h.

[0030] The present invention also claims to protect a catalytic cracking catalyst carrier prepared by using the above preparation method.

[0031] The present invention also claims to protect an application of the above catalyst carrier in the preparation of a catalytic cracking catalyst, wherein the catalyst is made of 85-99 wt% of the catalyst carrier and 1-15 wt% of the active component; the active component is an alkali metal oxide and / or an alkaline earth metal oxide.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1) The present invention provides a catalytic cracking catalyst carrier, its preparation method and application. After mixing modified cellulose into the carrier, on the one hand, the pore structure of the carrier is improved, and on the other hand, the wear resistance of the carrier is improved by phosphorus modification. In addition, carboxyl groups and amino groups improve the immobilization performance of the carrier for the active component, and improve the service life of the prepared catalyst; the carrier has a large pore volume and specific surface area, and at the same time has excellent wear resistance, can maintain a stable structure for a long time at high temperature, can withstand the temperature and hydrothermal conditions of the catalytic cracking reaction, maintain the carbon deposition capacity of the carrier during the long-term thermal conversion process, and can effectively improve the yield of light olefins.

[0034] 2) The present invention provides a modified cellulose. First, carboxymethyl cellulose is oxidized with periodic acid to obtain oxidized cellulose containing both carboxyl and aldehyde groups. Then, through the Schiff base reaction between the aldehyde group in the oxidized cellulose and the amino group in diethylenetriamine, imine (N=C) and amino groups are introduced into the cellulose to obtain Schiff base-modified cellulose. At this time, the cellulose chain has both negatively charged carboxyl groups and positively charged amino groups. The amphiphilic Schiff base-modified cellulose can have strong adsorption and chelation effects with the active component metal ions in the catalyst, thereby fixing the active component on the carrier, preventing the active component from being easily lost, and prolonging the service life of the catalyst. Finally, through the addition reaction between the active P-H bond in diethyl phosphite and the imine (N=C) in the Schiff base-modified cellulose, phosphorus element is introduced. After the modified cellulose is removed by roasting, rich pores can be formed in the carrier. At the same time, during roasting, phosphorus can also interact with Al2O3, and part of the Al-O in the carrier Al2O3 is replaced by P-O bonds, forming a more stable P-O-Al bond structure, which can effectively improve the anti-wear performance of the carrier. In addition, phosphorus modification can also strengthen the cracking reaction of carbocations and improve the yield of light olefins of the catalyst. Detailed implementation mode

[0035] In order to make the objectives, technical solutions and advantages of the present invention clearer, the following further elaborates on the present invention in conjunction with embodiments. Of course, the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0036] Unless otherwise specified, the chemical reagents and materials in the present invention are all purchased through market channels or synthesized from raw materials purchased through market channels.

[0037] Carboxymethyl cellulose was purchased from Shandong Yangzi Biotechnology Co., Ltd.

[0038] The present invention claims to protect a preparation method of a catalytic cracking catalyst carrier, which includes the following steps:

[0039] Pseudoboehmite is added to deionized water, stirred evenly, and then nitric acid solution is added and stirred to obtain a gel. Pseudoboehmite and deionized water are added to the gel, stirred for peptization, heated and stirred evenly to obtain a sol. Silicoaluminum material, deionized water and modified cellulose are added to the sol, mixed and beaten into a slurry, spray molded and dried to obtain microspheres. The microspheres are calcined to obtain the catalytic cracking catalyst carrier.

[0040] Specifically, when preparing the gel, the weight ratio of pseudoboehmite, deionized water and nitric acid solution is 0.2 - 0.5:1:0.03 - 0.05, and it can be 0.2:1:0.03, 0.3:1:0.04, 0.4:1:0.05, 0.5:1:0.05;

[0041] Specifically, the concentration of the nitric acid solution is 60-68wt%, which can be 60wt%, 63wt%, 65wt%, or 68wt%.

[0042] In an optional embodiment, when preparing the sol, the weight ratio of pseudo-boehmite and deionized water is 0.05-0.13:1, which can be 0.05:1, 0.06:1, 0.07:1, 0.08:1, 0.09:1, 0.10:1, 0.11:1, 0.12:1, or 0.13:1.

[0043] In an optional embodiment, when preparing the sol, the weight ratio of pseudo-boehmite to gel is 0.03-0.08:1, which can be 0.03:1, 0.04:1, 0.05:1, 0.06:1, 0.07:1, or 0.08:1.

[0044] Optionally, when preparing the sol, the heating and stirring conditions are stirring and heating at 60-100°C for 5-12h. The temperature can be 60°C, 70°C, 80°C, 90°C, or 100°C. The time can be 5h, 6h, 7h, 8h, 9h, 10h, 11h, or 12h.

[0045] Specifically, when preparing microspheres, the weight ratio of silicon aluminum material, deionized water, and modified cellulose is 0.6-1:1-1.5:0.01-0.1, and can be 0.6:1:0.01, 0.7:1.1:0.02, 0.8:1.2:0.03, 0.9:1.3:0.04, 1:1.4:0.05, 1:1.5:0.05, 1:1.5:0.1.

[0046] In an optional embodiment, when preparing microspheres, the weight ratio of the silicon-aluminum material to the sol is 0.05-0.2:1, and can be 0.05:1, 0.1:1, 0.15:1, or 0.2:1.

[0047] In an optional embodiment, when preparing microspheres, the particle size of the microspheres is 50-150 μm, and can be 50 μm, 100 μm, or 150 μm.

[0048] In an optional embodiment, the calcination conditions are 750-1100°C for 3-6h, the temperature can be 750°C, 800°C, 850°C, 900°C, 950°C, 1000°C, 1050°C, 1100°C, and the time can be 3h, 4h, 5h, 6h.

[0049] In an optional embodiment, when preparing microspheres, the silicon-aluminum material is one or more of pseudo-boehmite, diaspore, and clay.

[0050] Specifically, the method for preparing the modified cellulose comprises the following steps:

[0051] (1) Dissolve carboxymethyl cellulose in deionized water, then add periodic acid solution, adjust the pH of the system, stir and react, precipitate the reaction solution with acetone, filter, wash, dry and pulverize the product to obtain oxidized cellulose;

[0052] (2) Dissolve the oxidized cellulose in deionized water, then dropwise add diethylenetriamine with stirring, stir and react, filter, wash and dry the product to obtain Schiff base cellulose containing imine bonds;

[0053] (3) Disperse the Schiff base cellulose in DMF, stir to disperse evenly, then add diethyl phosphite, carry out reflux reaction under microwave heating, filter by suction, recrystallize the product with propanol, wash and dry under vacuum to obtain modified cellulose.

[0054] Specifically, in step (1), the weight - volume ratio of carboxymethyl cellulose to deionized water is 1 g: 10 - 20 mL, the concentration of the periodic acid solution is 5 - 10 wt%, and the weight ratio of carboxymethyl cellulose to the periodic acid solution is 1: 0.8 - 1; adjust the pH of the system to 1.5 - 4, and the stirring reaction condition is to react at 25 - 45 °C for 4 - 10 h.

[0055] Specifically, in step (2), the weight - volume ratio of oxidized cellulose to deionized water is 1 g: 30 - 40 mL; the weight ratio of oxidized cellulose to diethylenetriamine is 1: 1.56 - 2.74; the stirring reaction condition is to react at 50 - 60 °C for 8 - 12 h.

[0056] Specifically, in step (3), the weight ratio of Schiff base cellulose to diethyl phosphite is 1: 1.9 - 3.3, the microwave heating power is 400 - 500 W, and the reflux reaction time is 2 - 4 h.

[0057] The present invention also claims to protect a catalytic cracking catalyst carrier prepared by the above - mentioned preparation method.

[0058] The present invention also claims to protect the application of the above - mentioned catalyst carrier in the preparation of a catalytic cracking catalyst. The catalyst comprises 85 - 99 wt% of the catalyst carrier and 1 - 15 wt% of the active component. The proportion of the catalyst carrier can be 85 wt%, 90 wt%, 95 wt%, 99 wt%, and the proportion of the active component can be 1 wt%, 5 wt%, 10 wt%, 15 wt%; the active component is alkali metal oxide and / or alkaline earth metal oxide.

[0059] The following is a further illustration of the present invention through specific examples.

[0060] Example 1

[0061] A preparation method of a catalytic cracking catalyst carrier comprises the following steps:

[0062] (1) Dissolve 1 g of carboxymethyl cellulose in 20 mL of deionized water, then add 1 g of 10 wt% periodic acid solution, dropwise add sulfuric acid to adjust the pH of the system to 2, stir and react at 45 °C for 10 h, precipitate the reaction solution with acetone, filter, wash, dry and pulverize the product to obtain oxidized cellulose;

[0063] (2) Dissolve 1 g of oxidized cellulose in 40 mL of deionized water, then dropwise add 2.74 g of diethylenetriamine with stirring, stir and react at 60 °C for 12 h, filter, wash and dry the product to obtain Schiff base cellulose containing imine bonds;

[0064] (3) Disperse 1 g of Schiff base cellulose in 35 mL of DMF, stir to disperse evenly, then add 3.3 g of diethyl phosphite, heat under reflux with 500 W microwave for 4 h, filter by suction, recrystallize the product with propanol, wash and dry under vacuum to obtain modified cellulose;

[0065] (4) Mix 132.7 g of pseudoboehmite powder and 530.8 g of distilled water evenly, then slowly add 16.1 g of 63 wt% concentrated nitric acid, stir to obtain a gel; then add 42.3 g of pseudoboehmite powder and 400 g of distilled water to the gel, stir for peptization, mix evenly and heat at 85 °C for 6 h to form a sol; add 200 g of pseudoboehmite, 200 g of distilled water and 10 g of modified cellulose to the sol, mix and beat, then obtain microspheres through spray forming and drying; calcine the microspheres prepared in the above steps at 970 °C for 3 h to obtain a catalytic cracking catalyst support.

[0066] An application of a catalyst support in the preparation of a catalytic cracking catalyst, comprising the following steps:

[0067] Take 17.2 g of calcium nitrate tetrahydrate and add it to 182 g of deionized water, stir evenly to make a solution, add 200 g of the support, stir, impregnate for 12 h, dry in an oven at 120 °C, transfer to a muffle furnace and calcine at 900 °C for 3 h to obtain a catalytic cracking catalyst.

[0068] Example 2

[0069] A preparation method of a catalytic cracking catalyst support, comprising the following steps:

[0070] (1) Dissolve 1 g of carboxymethyl cellulose in 18 mL of deionized water, then add 1 g of 10 wt% periodic acid solution, dropwise add sulfuric acid to adjust the pH of the system to 2, stir and react at 40 °C for 8 h, precipitate the reaction solution with acetone, filter, wash, dry and pulverize the product to obtain oxidized cellulose;

[0071] (2) Dissolve 1 g of oxidized cellulose in 40 mL of deionized water, then dropwise add 2.35 g of diethylenetriamine under stirring, and stir and react at 60 °C for 11 h. Filter, wash, and dry the product to obtain Schiff-base cellulose containing imine bonds;

[0072] (3) Disperse 1 g of Schiff-base cellulose in 35 mL of DMF, stir to disperse evenly, then add 2.83 g of diethyl phosphite, and heat and reflux under 500 W microwave for 3 h. Filter by suction, recrystallize the product with propanol, wash, and dry under vacuum to obtain modified cellulose;

[0073] (4) Mix 375 g of pseudo-boehmite powder and 1500 g of distilled water evenly, then slowly add 45 g of 63 wt% concentrated nitric acid, and stir to obtain a gel; then add 150 g of pseudo-boehmite powder and 1200 g of distilled water to the gel, stir for peptization, mix evenly and heat at 85 °C for 6 h to form a sol; add 500 g of pseudo-boehmite, 100 g of clay, 600 g of distilled water, and 24 g of modified cellulose to the sol, mix and beat into a slurry, then spray and form, dry to obtain microspheres; calcine the above microspheres at 950 °C for 3 h to obtain a catalytic cracking catalyst support.

[0074] An application of a catalyst support in the preparation of a catalytic cracking catalyst, comprising the following steps:

[0075] Take 17.2 g of calcium nitrate tetrahydrate, add 182 g of deionized water, stir evenly to make a solution, add 200 g of the above support, stir, impregnate for 12 h, dry in an oven at 120 °C, transfer to a muffle furnace and calcine at 650 °C for 2 h to obtain a catalytic cracking catalyst.

[0076] Example 3

[0077] A preparation method of a catalytic cracking catalyst support, comprising the following steps:

[0078] (1) Dissolve 1 g of carboxymethyl cellulose in 15 mL of deionized water, then add 0.8 g of 10 wt% periodic acid solution, dropwise add sulfuric acid to adjust the pH of the system to 2, stir and react at 35 °C for 6 h, precipitate the reaction solution with acetone, filter, wash, dry, and pulverize the product to obtain oxidized cellulose;

[0079] (2) Dissolve 1 g of oxidized cellulose in 35 mL of deionized water, then dropwise add 1.95 g of diethylenetriamine under stirring, and stir and react at 55 °C for 9 h. Filter, wash, and dry the product to obtain Schiff-base cellulose containing imine bonds;

[0080] (3) Disperse 1 g of Schiff alkalized cellulose in 35 mL of DMF, stir and disperse evenly, then add 2.37 g of diethyl phosphite, reflux under 500 W microwave heating for 3 h, filter, recrystallize the product with propanol, wash, and vacuum dry to obtain modified cellulose;

[0081] (4) After 125 g of pseudo-boehmite powder and 500 g of distilled water are mixed evenly, 15 g of 63 wt% nitric acid is slowly added and stirred to obtain a gel; 50 g of pseudo-boehmite powder and 400 g of distilled water are added to the gel, stirred to degelatinize, and after mixing evenly, heated at 85°C for 6 h to form a sol; 100 g of pseudo-boehmite and 100 g of diaspore, 200 g of distilled water, and 6 g of modified cellulose are added to the sol, mixed and slurried, and then spray-formed and dried to obtain microspheres; the above microspheres are calcined at 950°C for 4 h to obtain a catalytic cracking catalyst carrier.

[0082] A use of a catalyst carrier in preparing a catalytic cracking catalyst comprises the following steps:

[0083] Take 26.4 g of magnesium nitrate tetrahydrate, add 182 g of deionized water, stir evenly to make a solution, add 200 g of the carrier, stir, soak for 8 hours, dry in an oven at 120°C, transfer to a muffle furnace and roast at 650°C for 2 hours to obtain a catalytic cracking catalyst.

[0084] Example 4

[0085] A method for preparing a catalytic cracking catalyst carrier comprises the following steps:

[0086] (1) Dissolve 1 g of carboxymethyl cellulose in 10 mL of deionized water, then add 0.8 g of 10 wt% periodic acid solution, drop sulfuric acid into the solution to adjust the pH of the solution to 2, stir and react at 25° C. for 4 h, precipitate the reaction solution with acetone, filter, wash, dry and crush the product to obtain oxidized cellulose;

[0087] (2) 1 g of oxidized cellulose was dissolved in 30 mL of deionized water, and then 1.56 g of diethylenetriamine was added dropwise under stirring, and the mixture was reacted at 50° C. for 8 h. The product was filtered, washed, and dried to obtain Schiff-alkalized cellulose containing imine bonds;

[0088] (3) Disperse 1 g of Schiff alkalized cellulose in 35 mL of DMF, stir and disperse evenly, then add 1.9 g of diethyl phosphite, reflux under 500 W microwave heating for 2 h, filter, recrystallize the product with propanol, wash, and vacuum dry to obtain modified cellulose;

[0089] (4) After 375 g of pseudo-boehmite powder and 1500 g of distilled water are mixed evenly, 45 g of 63 wt% nitric acid solution is slowly added and stirred to obtain a gel; 150 g of pseudo-boehmite powder and 1200 g of distilled water are added to the gel, stirred to degelatinize, and after mixing evenly, heated at 85°C for 6 h to form a sol; 100 g of diaspore, 300 g of pseudo-boehmite, 200 g of kaolin, 600 g of distilled water, and 12 g of modified cellulose are added to the sol, mixed and slurried, and then spray-formed and dried to obtain microspheres; the above microspheres are calcined at 950°C for 3 h to obtain a catalytic cracking catalyst carrier.

[0090] A use of a catalyst carrier in preparing a catalytic cracking catalyst comprises the following steps:

[0091] Take 26.4 g of magnesium nitrate tetrahydrate, add 182 g of deionized water, stir evenly to make a solution, add 200 g of the carrier, stir, soak for 12 hours, dry in an oven at 120°C, transfer to a muffle furnace and calcine at 550°C for 2 hours to obtain a catalytic cracking catalyst.

[0092] Comparative Example 1

[0093] A method for preparing a catalytic cracking catalyst carrier comprises the following steps:

[0094] (1) Dissolve 1 g of carboxymethyl cellulose in 20 mL of deionized water, then add 1 g of 10 wt% periodic acid solution, drop sulfuric acid into the solution to adjust the pH of the solution to 2, stir and react at 45° C. for 10 h, precipitate the reaction solution with acetone, filter, wash, dry and crush the product to obtain oxidized cellulose;

[0095] (2) 1 g of oxidized cellulose was dissolved in 40 mL of deionized water, and then 2.74 g of diethylenetriamine was added dropwise under stirring, and the mixture was reacted at 60° C. for 12 h. The product was filtered, washed, and dried to obtain Schiff-alkalized cellulose containing imine bonds;

[0096] (3) After 132.7 g of pseudo-boehmite powder and 530.8 g of distilled water are mixed evenly, 16.1 g of 63 wt% concentrated nitric acid is slowly added and stirred to obtain a gel; 42.3 g of pseudo-boehmite powder and 400 g of distilled water are added to the gel, stirred to degelatinize, and after mixing evenly, heated at 85° C. for 6 h to form a sol; 200 g of pseudo-boehmite, 200 g of distilled water, and 10 g of Schiff-alkalized cellulose are added to the sol, mixed and slurried, and then spray-formed and dried to obtain microspheres; the microspheres prepared in the above steps are calcined at 970° C. for 3 h to obtain a catalytic cracking catalyst carrier.

[0097] A use of a catalyst carrier in preparing a catalytic cracking catalyst comprises the following steps:

[0098] 17.2 g of calcium nitrate tetrahydrate was added to 182 g of deionized water and stirred evenly to form a solution. 200 g of a carrier was added, stirred, and impregnated for 12 h, then dried in an oven at 120 °C, transferred to a muffle furnace and calcined at 900 °C for 3 h to obtain a catalytic cracking catalyst.

[0099] Comparative Example 2

[0100] A preparation method of a catalytic cracking catalyst carrier includes the following steps:

[0101] (1) Dissolve 1 g of carboxymethyl cellulose in 20 mL of deionized water, then add 1 g of 10 wt% periodic acid solution, dropwise add sulfuric acid to adjust the pH of the system to 2, stir and react at 45 °C for 10 h, precipitate the reaction solution with acetone, filter, wash, dry, and pulverize the product to obtain oxidized cellulose;

[0102] (2) Mix 132.7 g of pseudo-boehmite powder and 530.8 g of distilled water evenly, slowly add 16.1 g of 63 wt% concentrated nitric acid, stir to obtain a gel; then add 42.3 g of pseudo-boehmite powder and 400 g of distilled water to the gel, stir for peptization, mix evenly and heat at 85 °C for 6 h to form a sol; add 200 g of pseudo-boehmite, 200 g of distilled water, and 10 g of oxidized cellulose to the sol, mix and beat, then obtain microspheres through spray forming and drying; calcine the microspheres prepared in the above steps at 970 °C for 3 h to obtain a catalytic cracking catalyst carrier.

[0103] An application of a catalyst carrier in the preparation of a catalytic cracking catalyst includes the following steps:

[0104] 17.2 g of calcium nitrate tetrahydrate was added to 182 g of deionized water and stirred evenly to form a solution. 200 g of a carrier was added, stirred, and impregnated for 12 h, then dried in an oven at 120 °C, transferred to a muffle furnace and calcined at 900 °C for 3 h to obtain a catalytic cracking catalyst.

[0105] Regarding the physical and chemical properties of the carriers prepared in Examples 1-4 and Comparative Examples 1-2, the specific data are shown in Table 1.

[0106] Table 1 Physical and Chemical Properties of the Carrier

[0107]

[0108] The performance evaluation of the heavy oil catalytic cracking reaction of the catalyst was carried out on a 100 mL fixed-bed fluidized bed reaction device. The catalyst loading was 100 g, the reaction temperature was 710 °C, the reaction pressure was atmospheric pressure, and the weight hourly space velocity of the raw material was 6 h -1, after the product is cooled and the gas-liquid separation is carried out, the gas composition is analyzed by an Agilent 7890 gas chromatograph equipped with an Al2O3 capillary column and a flame ionization detector (FID). Programmed temperature rise is adopted, and quantitative analysis is carried out using the correction factor; the carbon on the spent catalyst is quantitatively analyzed by an EA-2000 carbon-sulfur detector, and the experimental results are shown in Table 2.

[0109] In the table, the catalyst coke capacity is defined as: the percentage of coke on the spent catalyst in the coke generated by the reaction, and it is calculated according to the following formula:

[0110] Catalyst coke capacity = 100 × Coke yield on spent catalyst / Coke production rate

[0111] Reaction raw material: Changqing atmospheric residue oil, density 921.1 kg / m 3 , hydrogen content 12.62%, raw material composition: saturated hydrocarbons 64.3%, aromatics 17.5%, resins and asphaltenes 18.2%, residual carbon 4.1%.

[0112] Table 2 Catalytic cracking reaction performance of the catalyst

[0113]

[0114] It can be seen from the data in Table 2 that the catalyst prepared by the method of the present invention is used for heavy oil cracking to produce olefins, and has excellent performance. Compared with the contrast agent, while achieving higher ethylene, propylene and total olefin yields, the coke capacity of the catalyst is greatly improved. During industrial application, the coke generated by the reaction can be completely brought into the regenerator for burning, meeting the demand of the heat balance of the two reactors, without taking additional combustion measures, reducing the complexity of the system, and at the same time avoiding part of the coke depositing in the settler in the form of coke powder or entering the subsequent oil and gas system, thereby avoiding the blockage of the settler and the oil and gas system, and improving the quality of the produced heavy oil products.

[0115] In order to test the structural stability of the catalyst prepared by the method of the present invention, simulating the high-temperature and high-hydrothermal environment during the use of the catalyst, the prepared catalyst was subjected to hydrothermal treatment (850 °C, 100% water vapor) with various durations and relatively harsh conditions. By measuring the changes in specific surface area and pore volume, the hydrothermal stability performance of the catalyst was determined, and the test results are shown in Table 3.

[0116] Table 3 Test results of catalyst hydrothermal stability

[0117]

[0118]

[0119] It can be seen from the data in Table 3 that the catalyst prepared by the method of the present invention has good hydrothermal resistance and stable structure, and is suitable for the high-temperature and high-hydrothermal environment of heavy oil thermal cracking.

[0120] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention should cover within the protection scope of the present invention any equivalent substitution or change made according to the technical solution and inventive concept of the present invention.

Claims

1. A preparation method of a catalytic cracking catalyst carrier, characterized in that, The steps include: Pseudo-boehmite is added to deionized water, stirred evenly, and then a nitric acid solution is added and stirred to obtain a gel; pseudo-boehmite and deionized water are added to the gel, stirred to dissolve the gel, heated and stirred evenly to obtain a sol; silicon-aluminum material, deionized water, and modified cellulose are added to the sol, mixed and slurried, spray-formed, and dried to obtain microspheres; the microspheres are calcined to obtain the catalytic cracking catalyst carrier.

2. The preparation method according to claim 1, characterized in that, When preparing the gel, the weight ratio of pseudo-boehmite, deionized water and nitric acid solution is 0.2-0.5:1:0.03-0.05; the concentration of the nitric acid solution is 60-68wt%.

3. The preparation method according to claim 1, characterized in that, When preparing the sol, the weight ratio of pseudo-boehmite to deionized water is 0.05-0.13:

1.

4. The preparation method according to claim 1, wherein When preparing the sol, the weight ratio of pseudo-boehmite to gel is 0.03-0.08:

1.

5. The preparation method according to claim 1, characterized in that, When preparing the sol, the heating and stirring conditions are stirring and heating at 60-100°C for 5-12 hours.

6. The preparation method according to claim 1, wherein, When preparing microspheres, the weight ratio of silicon-aluminum material, deionized water and modified cellulose is 0.6-1:1-1.5:0.01-0.

1.

7. The preparation method according to claim 1, characterized in that, When preparing microspheres, the weight ratio of the silicon-aluminum material to the sol is 0.05-0.2:

1.

8. The preparation method according to claim 1, wherein When preparing microspheres, the particle size of the microspheres is 50 to 150 μm.

9. The preparation method according to claim 1, characterized in that, The calcination conditions are 750-1100°C for 3-6 hours.

10. The preparation method according to claim 1, characterized in that, When preparing microspheres, the silicon-aluminum material is one or more of pseudo-boehmite, diaspore, and clay.

11. The preparation method according to claim 1, characterized in that, The preparation method of the modified cellulose comprises the following steps: (1) dissolving carboxymethyl cellulose in deionized water, then adding periodic acid solution, adjusting the pH of the system, stirring the reaction, precipitating the reaction solution with acetone, filtering, washing, drying, and crushing the product to obtain oxidized cellulose; (2) dissolving oxidized cellulose in deionized water, then adding diethylenetriamine dropwise under stirring, stirring for reaction, filtering, washing, and drying the product to obtain Schiff-alkalized cellulose containing imine bonds; (3) Dispersing the Schiff alkalized cellulose in DMF, stirring and dispersing the cellulose uniformly, then adding diethyl phosphite, heating the cellulose under microwave reflux, filtering the cellulose, recrystallizing the cellulose with propanol, washing the cellulose, and vacuum drying the cellulose to obtain modified cellulose.

12. The preparation method according to claim 11, characterized in that, In step (1), the weight volume ratio of carboxymethyl cellulose to deionized water is 1 g: 10-20 mL, the concentration of the periodic acid solution is 5-10 wt %, and the weight ratio of carboxymethyl cellulose to the periodic acid solution is 1: 0.8-1; the pH of the system is adjusted to 1.5-4, and the stirring reaction conditions are 25-45° C. and the reaction is carried out for 4-10 hours.

13. The preparation method according to claim 11, characterized in that, In step (2), the weight volume ratio of oxidized cellulose to deionized water is 1 g: 30-40 mL; the weight ratio of oxidized cellulose to diethylenetriamine is 1: 1.56-2.74; and the stirring reaction conditions are 50-60° C. for 8-12 hours.

14. The preparation method according to claim 11, characterized in that, In step (3), the weight ratio of Schiff alkalized cellulose to diethyl phosphite is 1:1.9-3.3, the microwave heating power is 400-500W, and the reflux reaction time is 2-4h.

15. A catalytic cracking catalyst carrier prepared by the preparation method according to any one of claims 1 to 14.

16. Use of a catalyst support as described in claim 15 in the preparation of a fluid catalytic cracking catalyst, characterized in that, The catalyst is made of 85-99 wt% of a catalyst support and 1-15 wt% of an active component; the active component is an alkali metal oxide and / or an alkaline earth metal oxide.

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