Process for the preparation of a catalytic cracking aid for reducing the coke yield and for the production of diesel, catalytic cracking catalyst and process for the preparation

Abstract

The application discloses a preparation method of a catalytic cracking aid for reducing coke yield and increasing diesel yield, and comprises the following steps: mixing pseudo-boehmite and deionized water, adding an acidic substance to perform peptization treatment, then mixing with magnesium oxide slurry, adding a surfactant to perform crystallization reaction, and obtaining the catalytic cracking aid. The catalytic cracking aid is obtained by mixing the acid-treated pseudo-boehmite with the magnesium oxide slurry and then performing crystallization under the action of the surfactant, and the catalytic cracking aid can increase the alumina matrix content and improve the number of mesopores while reducing the content of molecular sieve and the acid amount. The catalytic cracking aid can control the amount of strong Lewis acid in the catalyst matrix, avoid the number of strong Lewis acid sites that tend to produce coke, reduce the coke yield, and increase the diesel yield.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of catalytic cracking of petroleum materials, in particular to a preparation method of a catalytic cracking aid for reducing coke yield and increasing diesel yield, a catalytic cracking catalyst and a preparation method. BACKGROUND

[0002] In recent years, with the industrial transformation and upgrading, the rapid development of new energy, the growth rate of China's refined oil consumption has slowed down significantly, and the apparent consumption of diesel has decreased year by year since 2015. Despite this, due to factors such as logistics transportation, infrastructure, industrial and manufacturing fields, export quotas, and especially seasonal and policy factors, the demand for diesel will increase significantly with regional characteristics, leading to an increase in the production enthusiasm of independent refineries. Therefore, under the premise of unchanged raw materials and properties, from the perspective of reducing carbon emissions and energy saving and consumption reduction, it is of great significance to study the catalytic cracking catalyst for reducing coke yield and increasing diesel yield to improve energy utilization efficiency, reduce energy consumption, and improve efficiency of refineries.

[0003] Diesel mainly includes straight-run diesel and secondary processing diesel. Due to the heavy crude oil in China, secondary processing is necessary to achieve lightening of heavy crude oil. Diesel produced by secondary processing such as catalytic cracking, hydrocracking, and delayed coking accounts for more than 60% of the total diesel. Catalytic diesel produced by catalytic cracking accounts for more than two-thirds of the secondary processing diesel. At the same time, the catalytic cracking unit is flexible in operation, so improving the diesel yield of catalytic cracking is crucial to increasing the diesel production of refineries. In the process of catalytic cracking, changes and optimization of operating conditions and the use of high-yield diesel catalysts are the main measures to increase diesel production.

[0004] The diesel yield and diesel-gasoline ratio of the catalytic cracking unit increase with the decrease of the conversion rate, but the total light oil yield decreases, and the heavy oil yield increases. Therefore, in order to increase diesel production, the catalytic cracking unit needs to properly control the conversion rate. However, changing the operating parameters of catalytic cracking to increase diesel production actually reduces the primary conversion rate to reduce the intermediate distillate re-cracking to increase diesel yield. With the decrease of the primary conversion rate, the unit processing capacity will also decrease, the coke yield will increase, and the gas production will increase. In addition to the adjustment of the operating process, the catalyst, as the core technology of catalytic cracking, has a very important influence on improving diesel selectivity by adjusting the activity components and the pore distribution, density, strength, and type of acid centers on the substrate.

[0005] As disclosed in Chinese patent document CN108499600A, a catalytic cracking catalyst for high diesel yield and its preparation method are disclosed. The catalyst has high diesel yield and resistance to heavy metal pollution by using non-phosphorus acid boron containing boron material to adjust the acid structure of the catalyst. Chinese patent document CN110479362A controls the acid and basicity of Y molecular sieve, modifies MFI molecular sieve and matrix, and increases the relative content of the matrix to achieve the effect of simultaneously producing propylene and diesel. Chinese patent document CN103861636A controls the peptization degree of pseudo-boehmite, increases the pore volume of the catalyst, and thus improves the heavy oil cracking capacity and diesel yield of the catalyst. Chinese patent document CN103506148A modifies Y-type molecular sieve with magnesium element, adjusts the acid strength of the molecular sieve, and thus reduces coke formation and improves diesel yield. Chinese patent document CN100413941C discloses a catalytic cracking catalyst for high diesel yield without zeolite component. The catalyst is prepared by calcining spray microspheres containing kaolin, pseudo-boehmite and water glass at high temperature, extracting the channels with strong alkali such as sodium hydroxide, and finally loading phosphorus and rare earth. In actual application, the catalyst can improve the diesel yield of the FCC catalytic device, improve the product distribution, and improve the utilization rate of existing catalyst varieties without changing the original catalyst used in the oil refining device. Chinese patent document CN102974335A discloses a catalytic cracking catalyst containing mesoporous silica-alumina material, clay and / or heat-resistant inorganic oxide. The diesel yield of the catalyst prepared by the catalyst is 16%-17%, and the coke conversion rate is less than 0.1%. Chinese patent document CN104492472A discloses a catalytic cracking catalyst comprising mixing template-containing SBA-15 raw powder or template-containing SBA-15 raw powder with introduced magnesium salt, binder and matrix, aging, spray forming and calcining, and finally obtaining the microspherical fluidized catalytic cracking catalyst. The catalyst is suitable for catalytic cracking of heavy distillate oil feedstock, reduces coke yield, and improves the yield of gasoline and diesel components. However, the technology does not effectively regulate the acid of the matrix while strengthening the pore structure of the catalyst, resulting in insignificant improvement in diesel yield.

[0006] The double aluminum bonding process can effectively improve the pore structure and acidity of the matrix, in which the aluminum sol is used to improve the strength of the catalyst, and the pseudo-boehmite is introduced into the matrix to improve the pore structure of the catalyst carrier. As found in Chinese Patent Document CN1436835 and Chinese Patent Document CN1690168, calcining the pseudo-boehmite at 150-400°C can obtain mesoporous and macroporous alumina, so that the matrix of the catalyst has an open pore structure, which increases the pore volume and pore size of the catalyst, strengthens the cracking of heavy oil macromolecules, thereby reducing the coke yield and having a certain anti-metal pollution capacity. Chinese Patent Document CN1098130 uses a double aluminum bonding process to significantly improve the heavy oil cracking capacity of the catalyst. Thereafter, the double aluminum bonding process is further improved, and a new shallow acidification process is developed, in which the acidification of the matrix is carried out at a lower acid / aluminum ratio, and the temperature aging process is cancelled. The colloidal particles form loose accumulation due to incomplete peptization, thereby increasing the open pores, and the proportion of aluminum sol in the double aluminum base is appropriately increased to increase the strength of the catalyst. Chinese Patent Document CN103506148A discloses a catalytic cracking catalyst for reducing coke yield and increasing diesel production, which contains a modified Y-type molecular sieve, a magnesium-containing ultrastable Y-type molecular sieve, clay, and an inorganic oxide binder; the modified Y-type molecular sieve catalyst contains a "three-interaction and three-calcination" phosphorus and rare earth modified Y-type molecular sieve, which can produce more diesel and reduce coke yield. Chinese Patent Document CN107433170A discloses a magnesium-aluminum sol used as a binder in a catalytic cracking catalyst; the magnesium-aluminum sol can also be modified with a phosphorus compound and / or a rare earth compound, and the final catalyst meets the industrial use requirements in terms of strength and activity, and the attrition index of the catalyst is significantly reduced.

[0007] To further improve the pore structure, a certain amount of pore distribution improver is added to the catalyst on the basis of the double aluminum bonding process. For example, in Chinese Patent Document CN1293225 and Chinese Patent Document CN1388213, water glass is added as a pore distribution improver to make the matrix have more pores. The above technologies introduce macroporous materials or strengthen the pore structure of the pseudo-boehmite by shallow acidification of the pseudo-boehmite, or adjust the acidity of the molecular sieve, thereby strengthening the cracking of heavy oil macromolecules. The purpose of introducing the magnesium-aluminum sol is to increase the colloidal solid content, thereby reducing energy consumption and production cost.

[0008] Although the above improvement schemes can increase diesel yield or reduce coke yield to some extent, they cannot achieve the simultaneous increase of diesel yield and reduction of coke yield. SUMMARY

[0009] In view of the problems in the prior art and the direction for improvement, the present application provides a preparation method of a catalytic cracking aid for reducing coke yield and increasing diesel yield, which solves the technical problem that high diesel yield and low coke yield are difficult to be achieved simultaneously in the prior art by strengthening the pore structure of the matrix and further regulating the L acid acidity of the matrix when designing the diesel yield catalyst.

[0010] To achieve the above-mentioned purposes, the present application provides the following technical solutions:

[0011] A preparation method of a catalytic cracking aid for reducing coke yield and increasing diesel yield, comprising the following steps:

[0012] Mixing pseudo-boehmite and deionized water, and then adding an acidic substance for peptization treatment to obtain a pseudo-boehmite slurry;

[0013] Mixing the pseudo-boehmite slurry and a magnesium oxide slurry, and then adding a surfactant for crystallization reaction to obtain the catalytic cracking aid for reducing coke yield and increasing diesel yield;

[0014] The weight ratio of the pseudo-boehmite to the magnesium oxide slurry is (0.2-0.8):1, calculated based on dry basis of aluminum oxide and magnesium oxide;

[0015] The temperature of the crystallization reaction is 50-95 DEG C, and the time is 10-24 h;

[0016] The mass ratio of the catalytic cracking aid to the surfactant is 1:0.01-0.05 on dry basis.

[0017] Optionally, in the preparation method of the catalytic cracking aid for reducing coke yield and increasing diesel yield, the mass ratio of the pseudo-boehmite to the acidic substance is 0.05-0.25, calculated based on dry basis of aluminum oxide;

[0018] The temperature of the peptization treatment is 40-80 DEG C, and the time is 1-3 h.

[0019] Optionally, in the preparation method of the catalytic cracking aid for reducing coke yield and increasing diesel yield, the solid content of the pseudo-boehmite slurry is 0.15-0.25.

[0020] The magnesium oxide slurry is a mixed slurry of magnesium oxide and water, and the solid content of the magnesium oxide slurry is 0.2-0.4.

[0021] Optionally, in the preparation method of the catalytic cracking aid for reducing coke yield and increasing diesel yield, the surfactant is hexadecyl trimethyl ammonium bromide or hexadecyl trimethyl ammonium chloride.

[0022] The acid substance is selected from one or more of hydrochloric acid, nitric acid, formic acid and acetic acid;

[0023] The crystallization reaction mode is any one of static, dynamic or intermittent dynamic crystallization.

[0024] On this basis, the application provides a catalytic cracking catalyst, which comprises 5wt%-20wt% of molecular sieve, 25wt%-40wt% of inorganic oxide binder in terms of oxide, 0-3wt% of rare earth additive in terms of oxide, 5wt%-15wt% of magnesium-aluminum matrix material in dry basis and 30wt%-50wt% of modified clay in dry basis, based on 100% of the total mass of the catalytic cracking catalyst.

[0025] The magnesium-aluminum matrix material is the catalytic cracking aid for reducing coke yield and increasing diesel production prepared by the method for preparing the catalytic cracking aid for reducing coke yield and increasing diesel production.

[0026] Optionally, in the catalytic cracking catalyst provided by the application, the molecular sieve is selected from Y-type molecular sieve or modified Y-type molecular sieve, and the modified Y-type molecular sieve is selected from one or more of REUSY molecular sieve, HRSY-1 molecular sieve, RDSY molecular sieve and MASY molecular sieve.

[0027] Optionally, in the catalytic cracking catalyst provided by the application, the modified clay is acid-modified clay, and the method for modifying the clay with acid is not limited in particular, and a conventional method in the industry can be used, for example, the clay is slurried with deionized water, then stirred uniformly at 60-70°C, an acid substance is added and the pH value of the system is maintained at 0-2, and the stirring is continued for not less than 1h to obtain the acid-modified clay. The clay is selected from one or more of kaolin, halloysite, montmorillonite, sepiolite, hydrotalcite and rectorite.

[0028] The rare earth additive is a water-soluble rare earth compound, and is preferably one or more of chloride or nitrate of lanthanum, cerium, praseodymium, neodymium and yttrium.

[0029] The inorganic oxide binder is one or more of aluminum sol, silicon sol, pseudo-boehmite and silicon-aluminum sol.

[0030] The application further provides a preparation method of the catalytic cracking catalyst, comprising the following steps:

[0031] 1) adding an inorganic oxide binder to the modified clay and controlling the pH value of the system to be 1-3: then adding a magnesium-aluminum matrix material and a molecular sieve to form a slurry;

[0032] 2) performing spray drying and calcination and solidification on the slurry to obtain a solidified catalyst; and washing and drying the solidified catalyst to obtain the catalytic cracking catalyst.

[0033] The preparation method of the catalytic cracking catalyst provided by the present application is not limited in the specific modification method, and a conventional method can be used, for example, the following method can be used:

[0034] The clay is slurried with deionized water, and then stirred uniformly at 60-70°C, and then hydrochloric acid, nitric acid or formic acid and other acidic substances are added to maintain the pH value of the system between 0-2, and then continuously stirred for not less than 1h to obtain the modified clay.

[0035] Optionally, in the preparation method of the catalytic cracking catalyst provided by the present application, the step 1) of forming the slurry further comprises the step of adding a rare earth additive, that is, adding an inorganic oxide binder to the modified clay, and controlling the pH value of the system to be 1-3: then adding a magnesium-aluminum matrix material, a rare earth additive and a molecular sieve to form a slurry.

[0036] Optionally, in the preparation method of the catalytic cracking catalyst provided by the present application, the temperature of the calcination and solidification is 300-600°C, and the time is 0.5-2h.

[0037] The washing is performed using an aqueous ammonium chloride solution, and the temperature of the washing is 30-90°C; preferably, the mass ratio of the solidified catalyst to the aqueous ammonium chloride solution is 1:(2-10), and the mass ratio of ammonium chloride to water in the aqueous ammonium chloride solution is (1-10):100.

[0038] Optionally, in the preparation method of the catalytic cracking catalyst provided by the present application, the slurry is dried by a spray drying method, and the specific parameters of the spray drying are not limited, and a conventional method can be used. For example, the inlet temperature is 350-450°C, and the outlet temperature is 120-200°C.

[0039] Compared with the prior art, the present application has the following beneficial effects:

[0040] The catalyst for producing diesel fuel should have strong heavy oil cracking ability and weak secondary cracking ability of middle distillate, that is, rich mesopore, high acid amount and moderate acid strength. Since the micropore of the catalyst mainly comes from the molecular sieve, in order to reduce the content of micropore in the catalyst and the amount of strong and weak acid sites of micropore, the molecular sieve with appropriate acidity should be used and its content in the catalyst should be reduced to reduce the re-cracking of the middle distillate. The mesopore of the catalyst mainly comes from the matrix component, and increasing the content of the mesopore requires increasing the content of the alumina matrix, that is, the pseudo-boehmite, in the catalyst. However, increasing the content of the alumina matrix leads to the increase of the amount of strong Lewis acid in the catalyst, resulting in the increase of the tendency of the catalyst to coke. In the catalytic cracking process, the catalytic activity comes from the acid sites on the surface of the molecular sieve, and there are Bronsted acid and Lewis acid in the molecular sieve. The B acid is the acidity of the aluminum oxide tetrahedron on the framework of the molecular sieve, and it follows the carbonium ion catalytic cracking reaction. The L acid is mainly distributed in the catalyst matrix, the defect site of the molecular sieve and the non-framework aluminum. The matrix plays a role in cracking large molecules into intermediate transition molecules in the heavy oil cracking, and the weak L acid helps to initiate the cracking. When the L acid is strong, it is easy to adsorb unsaturated hydrocarbons and difficult to desorb, causing dehydrogenation and comprehensive reaction, and finally forming coke. Therefore, while the matrix is used to strengthen the pore structure of the catalyst, how to control the L acid acidity of the matrix and increase the diesel yield while reducing the coke yield is a difficulty.

[0041] Beneficial effect 1: The catalytic cracking aid is obtained by mixing the acid-treated pseudo-boehmite and the magnesium oxide slurry (a mixture of magnesium oxide and water) and then crystallizing under the action of the surfactant. The catalyst prepared by using the catalytic cracking aid can increase the content of the alumina matrix and the number of mesopores while reducing the content of the molecular sieve and the acid amount. The catalyst can control the amount of strong Lewis acid in the catalyst matrix, avoid the increase of the amount of strong Lewis acid sites that tend to produce coke, reduce the coke yield and increase the diesel yield.

[0042] Beneficial effect 2: The catalytic cracking catalyst provided by the application uses the magnesium-aluminum matrix material prepared by the method provided by the application, combines modified clay, molecular sieve and inorganic oxide binder, and the components cooperate with each other to increase the number of macropores and introduce an appropriate amount of Bronsted acid, which can further enhance the heavy oil large molecule cracking performance. At the same time, the catalyst is combined with heavy metal resistance and the pore structure of the catalyst is optimized to increase the yield of diesel fuel while reducing the coke yield of the catalyst. DETAILED DESCRIPTION

[0043] The following detailed description of the embodiments of the present application is based on the premise of the technical solutions of the present application, and detailed implementation manners and processes are given, but the protection scope of the present application is not limited to the following examples. The experimental methods not specified in the following examples are generally carried out under conventional conditions.

[0044] Example 1

[0045] (1) Preparation of magnesium-aluminum matrix material (catalytic cracking aid)

[0046] Take 161 grams of pseudo-boehmite, add 505 grams of deionized water, and then add 10 grams of concentrated hydrochloric acid with a concentration of 36%-38% under continuous stirring. Then, heat to 40°C and maintain for 1 hour to obtain a sol of the pseudo-boehmite after peptization.

[0047] Take 20 grams of magnesium oxide, add 50 grams of deionized water, and mix well to obtain a slurry of magnesium oxide. Add the slurry of magnesium oxide to the above-mentioned slurry of pseudo-boehmite, and then add 1.2 grams of cetyltrimethylammonium bromide. Stir for 30 minutes to obtain a magnesium-aluminum colloidal slurry.

[0048] Transfer the above-mentioned magnesium-aluminum colloidal slurry to a crystallization reactor for crystallization reaction at 50°C for 72 hours to obtain a magnesium-aluminum matrix material (i.e., a catalytic cracking aid). In the material, m(magnesium oxide):m(aluminum oxide)=0.2:1.

[0049] (2) Preparation of a catalyst

[0050] Take 1047 grams of kaolin, add 2412 grams of deionized water, and then add 210 grams of concentrated hydrochloric acid with a concentration of 36%-38% under continuous stirring. Heat to 70°C and maintain for 60 minutes under continuous stirring to obtain a modified clay. Then, add 806 grams of pseudo-boehmite, and stir for 60 minutes. At this time, the pH of the system is 2.5. Then, add 240 grams of the magnesium-aluminum matrix material slurry prepared in step (1), and then add 506 grams of RDSY molecular sieve, 102 grams of HRSY-1 molecular sieve, and 1059 grams of deionized water. Mix and stir well to obtain a slurry. Spray dry the slurry under the conditions of an inlet temperature of 350°C and an outlet temperature of 120°C. Solidify and calcine at 400°C for 2 hours. Then, take 500 grams of the solidified and calcined microspheres, and use a solution of 2500 grams of deionized water and 25 grams of ammonium chloride to wash at 60°C for 30 minutes. Filter and dry to obtain a catalytic cracking catalyst. Denoted as S1. The reaction performance is shown in Table 1.

[0051] In the catalytic cracking catalyst prepared in this example, the molecular sieve, the magnesium-aluminum matrix material, and the modified clay are based on dry basis, and the inorganic oxide binder is based on oxide. m(molecular sieve):m(inorganic oxide binder):m(magnesium-aluminum matrix material):m(modified clay)=25%:26%:5%:44%.

[0052] Example 2

[0053] (1) Preparation of magnesium-aluminum matrix material (catalytic cracking aid)

[0054] Take 161 grams of pseudo-boehmite, add 339 grams of deionized water, and under continuous stirring, add 15 grams of formic acid with a concentration of 99%, and heat to 50°C for 1 hour to obtain a slurry of the peptized pseudo-boehmite;

[0055] Take 30 grams of magnesium oxide, add 45 grams of deionized water, and mix well to obtain a slurry of the magnesium oxide; add the slurry of the magnesium oxide to the above-mentioned slurry of the pseudo-boehmite, and then add 2.6 grams of cetyltrimethylammonium bromide, and mix and stir for 30 minutes to obtain a magnesium-aluminum colloidal slurry;

[0056] Transfer the above-mentioned magnesium-aluminum colloidal slurry to a crystallization reactor for crystallization reaction, and react at 95°C for 10 hours to obtain a magnesium-aluminum matrix material. In this material, m(magnesium oxide):m(aluminum oxide)=0.3:1.

[0057] (2) Preparation of the catalyst

[0058] Take 905 grams of kaolin, add 2770 grams of deionized water, and under continuous stirring, add 201 grams of hydrochloric acid with a concentration of 36%-38%, and heat to 65°C for 60 minutes of continuous stirring to obtain a modified clay; then add 968 grams of pseudo-boehmite, at which time the pH of the system is 2.5, and stir for 60 minutes; add 800 grams of the magnesium-aluminum matrix material slurry prepared in step (1), and then add 506 grams of RDSY molecular sieve, 40 grams of lanthanum chloride, and 854 grams of deionized water, and mix and stir well to obtain a slurry; spray dry the slurry under the conditions of an inlet temperature of 380°C and an outlet temperature of 150°C, and solidify and calcine at 350°C for 1 hour; then take 500 grams of the solidified and calcined microspheres, and wash at 80°C for 30 minutes using a solution of 2000 grams of deionized water and 40 grams of ammonium chloride, and filter and dry to obtain a catalytic cracking catalyst. This is denoted as S2, and the reaction performance is shown in Table 1.

[0059] In the catalytic cracking catalyst prepared in this example, the molecular sieve, the magnesium-aluminum matrix material, and the modified clay are based on dry basis, and the inorganic oxide binder and the rare earth additive are based on oxide, and m(molecular sieve):m(inorganic oxide binder):m(rare earth additive):m(magnesium-aluminum matrix material):m(modified clay)=20%:31%:1%:10%:38%.

[0060] Example 3

[0061] (1) Preparation of magnesium-aluminum matrix material (catalytic cracking aid)

[0062] Take 161 grams of pseudo-boehmite, add 239 grams of deionized water, add 15 grams of 99% concentration acetic acid under continuous stirring, heat to 60°C for 1 hour, to obtain the sol of the solvated pseudo-boehmite;

[0063] Take 50 grams of magnesium oxide, add 75 grams of deionized water, mix well to obtain the magnesium oxide slurry; add the magnesium oxide slurry into the above pseudo-boehmite slurry, then add 4.5 grams of cetyltrimethylammonium chloride, mix and stir for 60 minutes to obtain the magnesium-aluminum colloidal slurry;

[0064] Transfer the above magnesium-aluminum colloidal slurry to a crystallization reactor for crystallization reaction at 80°C for 24 hours to obtain the magnesium-aluminum matrix material. In the material, m(magnesium oxide):m(alumina)=0.5:1.

[0065] (2) Preparation of the catalyst

[0066] Take 928 grams of kaolin, add 3841 grams of deionized water, add 262 grams of 36%-38% concentration hydrochloric acid under continuous stirring, heat to 60°C for 70 minutes, to obtain the modified clay; then add 1129 grams of pseudo-boehmite, at this time the pH of the system is 2.1, stir for 60 minutes; add 800 grams of the magnesium-aluminum matrix material slurry prepared in step (1), then add 305 grams of HRSY-1 molecular sieve, 40 grams of praseodymium chloride and 721 grams of deionized water, mix and stir well to obtain the slurry; spray dry under the conditions of inlet temperature 400°C and outlet temperature 150°C, solidify and calcine at 450°C for 1 hour; then take 500 grams of the solidified and calcined microspheres, wash at 90°C for 30 minutes using a solution of 2000 grams of deionized water and 80 grams of ammonium chloride, filter and dry to obtain the catalytic cracking catalyst. Denoted as S3, the reaction performance is shown in Table 1.

[0067] In the catalytic cracking catalyst prepared in this example, the molecular sieve, the magnesium-aluminum matrix material and the modified clay are based on dry basis, the inorganic oxide binder and the rare earth additive are based on oxide, m(molecular sieve):m(inorganic oxide binder):m(rare earth additive):m(magnesium-aluminum matrix material):m(modified clay)=15%:35%:1%:10%:39%.

[0068] Example 4

[0069] (1) Preparation of the magnesium-aluminum matrix material (catalytic cracking aid)

[0070] Take 161 grams of pseudo-boehmite, add 239 grams of deionized water, add 15 grams of 65%-68% concentration nitric acid under continuous stirring, heat to 60°C for 1 hour, to obtain the sol of the solvated pseudo-boehmite;

[0071] Take 80 grams of magnesium oxide, add 187 grams of deionized water, mix evenly, get magnesium oxide slurry; the magnesium oxide slurry is added to the above pseudo-boehmite slurry, 9 grams of cetyltrimethylammonium chloride is added, and the slurry is mixed and stirred for 60 minutes to obtain a magnesium-aluminum colloidal slurry;

[0072] The magnesium-aluminum colloidal slurry is transferred to a crystallization reactor for crystallization reaction at 70°C for 36 hours to obtain a magnesium-aluminum matrix material. In the material, m(magnesium oxide):m(alumina)=0.8:1.

[0073] (2) Preparation of catalyst

[0074] Take 1119 grams of erionite, add 3904 grams of deionized water, add 318 grams of 36%-38% concentrated hydrochloric acid under continuous stirring, heat to 70°C and continuously stir for 90 minutes to obtain modified clay; then add 968 grams of pseudo-boehmite, at this time the system pH=1.8, stir for 60 minutes; add 960 grams of magnesium-aluminum matrix material slurry prepared in step (1), and then add 204 grams of HRSY-1 molecular sieve, 28 grams of yttrium nitrate and 500 grams of deionized water, mix and stir evenly to obtain a slurry. Spray drying is carried out under the conditions of inlet temperature 420°C and outlet temperature 180°C, and solidification calcination is carried out at 450°C for 1 hour. After that, take 500 grams of solidification calcined microspheres, use a solution of 2000 grams of deionized water and 200 grams of ammonium chloride to wash at 70°C for 30 minutes, filter and dry to obtain a catalytic cracking catalyst. Denoted as S4, the reaction performance is shown in Table 1.

[0075] In the catalytic cracking catalyst prepared in this example, the molecular sieve, magnesium-aluminum matrix material and modified clay are based on dry basis, and the inorganic oxide binder and rare earth additive are based on oxide. m(molecular sieve):m(inorganic oxide binder):m(rare earth additive):m(magnesium-aluminum matrix material):m(modified clay)=10%:30%:1%:12%:47%.

[0076] Example 5

[0077] (1) Preparation of magnesium-aluminum matrix material (catalytic cracking aid)

[0078] Take 161 grams of pseudo-boehmite, add 239 grams of deionized water, add 20 grams of 65%-68% concentrated nitric acid under continuous stirring, heat to 80°C and keep for 1 hour to obtain a pseudo-boehmite slurry after peptization;

[0079] Take 20 grams of magnesium oxide, add 60 grams of deionized water, mix evenly to obtain a magnesium oxide slurry; the magnesium oxide slurry is added to the above pseudo-boehmite slurry, 4.2 grams of cetyltrimethylammonium chloride is added, and the slurry is mixed and stirred for 60 minutes to obtain a magnesium-aluminum colloidal slurry;

[0080] The magnesium-aluminum colloid slurry was transferred to a crystallization reactor for crystallization reaction at 90°C for 18 hours to obtain a magnesium-aluminum matrix material. In the material, m(magnesium oxide):m(aluminum oxide)=0.2:1.

[0081] (2) Preparation of the catalyst

[0082] Take 881 grams of sepiolite, add 3904 grams of deionized water, and add 248 grams of hydrochloric acid with a concentration of 36%-38% under continuous stirring, and heat to 70°C for 80 minutes of continuous stirring to obtain modified clay; then add 1290 grams of silica sol, at this time the pH of the system is 2.0, and stir for 60 minutes; add 1200 grams of the magnesium-aluminum matrix material slurry prepared in step (1), and then add 126 grams of RDSY molecular sieve, 129 grams of neodymium nitrate, and 310 grams of deionized water, mix and stir uniformly to obtain a slurry, and perform spray drying under the conditions of an inlet temperature of 450°C and an outlet temperature of 200°C, and solidify and calcine at 500°C for 0.5 hours; thereafter, take 500 grams of the solidified and calcined microspheres, wash at 45°C for 30 minutes using a solution formed from 2000 grams of deionized water and 100 grams of ammonium chloride, filter, and dry to obtain a catalytic cracking catalyst. Denoted as S5, and the reaction performance is shown in Table 1.

[0083] In the catalytic cracking catalyst prepared in this example, the molecular sieve, the magnesium-aluminum matrix material, and the modified clay are based on dry basis, and the inorganic oxide binder and the rare earth additive are based on oxide, and m(molecular sieve):m(inorganic oxide binder):m(rare earth additive):m(magnesium-aluminum matrix material):m(modified clay)=5%:40%:3%:15%:37%.

[0084] Example 6

[0085] (1) Preparation of the magnesium-aluminum matrix material (catalytic cracking aid)

[0086] Take 161 grams of pseudoboehmite, add 339 grams of deionized water, and add 25 grams of hydrochloric acid with a concentration of 36%-38% under continuous stirring, and heat to 80°C for 2 hours to obtain a pseudoboehmite slurry after peptization;

[0087] Take 50 grams of magnesium oxide, add 120 grams of deionized water, and mix uniformly to obtain a magnesium oxide slurry; add the magnesium oxide slurry to the above-mentioned pseudoboehmite slurry, and then add 6 grams of cetyltrimethylammonium chloride, and mix and stir for 60 minutes to obtain a magnesium-aluminum colloid slurry;

[0088] The magnesium-aluminum colloid slurry was transferred to a crystallization reactor for crystallization reaction at 95°C for 48 hours to obtain a magnesium-aluminum matrix material. In the material, m(magnesium oxide):m(aluminum oxide)=0.5:1.

[0089] (2) Preparation of the catalyst

[0090] Take 1190 grams of montmorillonite, add 3904 grams of deionized water, add 336 grams of hydrochloric acid with a concentration of 36% to 38% under continuous stirring, heat to 70°C for 60 minutes of continuous stirring, obtain modified clay; then add 806 grams of aluminum sol, at this time the pH of the system is 2.7, stir for 60 minutes; add 1040 grams of magnesium-aluminum matrix material slurry prepared in step (1), then add 253 grams of MASY molecular sieve, 80 grams of lanthanum chloride and 467 grams of deionized water, mix and stir uniformly to obtain a slurry, spray dry at an inlet temperature of 420°C and an outlet temperature of 150°C, solidify and calcine at 500°C for 0.5 hours, then take 500 grams of solidified and calcined microspheres, wash at 80°C for 30 minutes using a solution of 3000 grams of deionized water and 200 grams of ammonium chloride, filter and dry to obtain a catalytic cracking catalyst. Denoted as S6, the reaction performance is shown in Table 1.

[0091] In the catalytic cracking catalyst prepared in this example, the molecular sieve, magnesium-aluminum matrix material and modified clay are based on dry basis, the inorganic oxide binder and rare earth additive are based on oxide, and m(molecular sieve):m(inorganic oxide binder):m(rare earth additive):m(magnesium-aluminum matrix material):m(modified clay)=10%:25%:2%:13%:50%.

[0092] Example 7

[0093] (1) Preparation of magnesium-aluminum matrix material (catalytic cracking aid)

[0094] Take 161 grams of pseudoboehmite, add 257 grams of deionized water, add 15 grams of nitric acid with a concentration of 65% to 68% under continuous stirring, heat to 75°C for 3 hours to obtain a sol of pseudoboehmite;

[0095] Take 60 grams of magnesium oxide, add 137 grams of deionized water, mix uniformly to obtain a magnesium oxide slurry; add the magnesium oxide slurry to the above-mentioned pseudoboehmite slurry, then add 6 grams of cetyltrimethylammonium chloride, beat and mix and stir for 60 minutes to obtain a magnesium-aluminum colloid slurry;

[0096] Transfer the above-mentioned magnesium-aluminum colloid slurry to a crystallization reactor for crystallization reaction at 95°C for 18 hours to obtain a magnesium-aluminum matrix material. In this material, m(magnesium oxide):m(aluminum oxide)=0.6:1.

[0097] (2) Preparation of catalyst

[0098] Take 1012 grams of kaolin, add 3633 grams of deionized water, add 285 grams of hydrochloric acid with a concentration of 36% to 38% under continuous stirring, heat to 70°C and continue stirring for 90 minutes to obtain modified clay; then add 903 grams of pseudoboehmite, at this time the system pH = 1.5, stir for 60 minutes; add 1200 grams of magnesium-aluminum matrix material slurry prepared in step (1), then add 329 grams of REUSY molecular sieve, 60 grams of lanthanum chloride and 578 grams of deionized water, mix and stir uniformly to obtain a slurry, spray dry at an inlet temperature of 420°C and an outlet temperature of 160°C, solidify and calcine at 550°C for 0.5 hours, then take 500 grams of solidified and calcined microspheres, use a solution formed by 5000 grams of deionized water and 200 grams of ammonium chloride to wash at 35°C for 30 minutes, filter and dry to obtain a catalytic cracking catalyst. Denoted as S7, the reaction performance is shown in Table 1.

[0099] In the catalytic cracking catalyst prepared in this example, the molecular sieve, magnesium-aluminum matrix material and modified clay are based on dry basis, the inorganic oxide binder and rare earth additive are based on oxide, and m(molecular sieve):m(inorganic oxide binder):m(rare earth additive):m(magnesium-aluminum matrix material):m(modified clay) = 13%:28%:1.5%:15%:42.5%.

[0100] Comparative Example 1

[0101] Preparation of catalyst

[0102] Take 1143 grams of kaolin, add 2770 grams of deionized water, add 201 grams of hydrochloric acid with a concentration of 36% to 38% under continuous stirring, heat to 65°C and continue stirring for not less than 60 minutes to obtain modified clay; then add 968 grams of pseudoboehmite, at this time the system pH = 2.5, stir for 60 minutes; then add 506 grams of RDSY molecular sieve, 40 grams of lanthanum chloride and 854 grams of deionized water, mix and stir uniformly to obtain a slurry, spray dry at an inlet temperature of 380°C and an outlet temperature of 150°C, solidify and calcine at 350°C for 1 hour, then take 500 grams of solidified and calcined microspheres, use a solution formed by 2000 grams of deionized water and 40 grams of ammonium chloride to wash at 80°C for 30 minutes, filter and dry to obtain a catalytic cracking catalyst. Denoted as D1, the reaction performance is shown in Table 1.

[0103] In the catalytic cracking catalyst prepared in this example, the molecular sieve and modified clay are based on dry basis, the inorganic oxide binder and rare earth additive are based on oxide, and m(molecular sieve):m(inorganic oxide binder):m(rare earth additive):m(modified clay) = 20%:31%:1%:48%.

[0104] Comparative Example 2

[0105] Preparation of catalyst

[0106] Take 905 grams of kaolin, add 2770 grams of deionized water, add 201 grams of hydrochloric acid with a concentration of 36% to 38% under continuous stirring, heat to 65°C for not less than 60 minutes of continuous stirring, obtain modified clay; then add 968 grams of pseudoboehmite, add 151 grams of magnesium chloride, 2000 grams of deionized water, stir for 60 minutes; then add 506 grams of RDSY molecular sieve, 40 grams of lanthanum chloride and 854 grams of deionized water, mix and stir uniformly to obtain a slurry, spray dry at an inlet temperature of 380°C and an outlet temperature of 150°C, solidify and calcine at 350°C for 1 hour, then take 500 grams of solidified and calcined microspheres, use a solution of 2000 grams of deionized water and 40 grams of ammonium chloride to wash at 80°C for 30 minutes, filter and dry to obtain a catalytic cracking catalyst. Denoted as D2, the reaction performance is shown in Table 1.

[0107] The catalytic cracking catalyst prepared in the present comparative example has, on a dry basis, molecular sieve and modified clay, inorganic oxide binder, magnesium chloride and rare earth additive on an oxide basis, m(molecular sieve):m(inorganic oxide binder):m(magnesium oxide):m(rare earth additive):m(modified clay) = 20%:31%:1.5%:1%:46.5%.

[0108] Comparative Example 3

[0109] (1) Preparation of magnesium-aluminum matrix material (catalytic cracking aid)

[0110] Take 161 grams of pseudoboehmite, add 257 grams of deionized water, add 15 grams of nitric acid with a concentration of 65% to 68% under continuous stirring, heat to 75°C for 3 hours to obtain a pseudoboehmite slurry after peptization;

[0111] Take 60 grams of magnesium oxide, add 137 grams of deionized water, mix uniformly to obtain a magnesium oxide slurry; add the magnesium oxide slurry to the above-mentioned pseudoboehmite slurry, add 6 grams of cetyltrimethylammonium chloride, beat and mix and stir for 60 minutes to obtain a magnesium-aluminum colloid, which is ready for use;

[0112] In the magnesium-aluminum colloid, m(magnesium oxide):m(aluminum oxide) = 0.6:1.

[0113] (2) Preparation of catalyst

[0114] Take 1012 grams of kaolin, add 3633 grams of deionized water, add 285 grams of hydrochloric acid with a concentration of 36% to 38% under continuous stirring, heat to 70°C for 90 minutes under continuous stirring, obtain modified clay; then add 903 grams of pseudoboehmite, at this time the system pH = 1.5, stir for 60 minutes; add 1200 grams of magnesium-aluminum matrix material slurry prepared in step (1), then add 329 grams of REUSY molecular sieve, 60 grams of lanthanum chloride and 578 grams of deionized water, mix and stir uniformly, obtain slurry, spray dry at an inlet temperature of 420°C and an outlet temperature of 160°C, solidify and calcine at 550°C for 0.5 hours, then take 500 grams of solidified and calcined microspheres, use a solution of 5000 grams of deionized water and 200 grams of ammonium chloride to wash at 35°C for 30 minutes, filter and dry to obtain a catalytic cracking catalyst. Denoted as D3, the reaction performance is shown in Table 1.

[0115] In the catalytic cracking catalyst prepared in this example, the molecular sieve, magnesium-aluminum matrix material and modified clay are based on dry basis, the inorganic oxide binder and rare earth additive are based on oxide, and m(molecular sieve):m(inorganic oxide binder):m(rare earth additive):m(magnesium-aluminum matrix material):m(modified clay) = 13%:28%:1.5%:15%:42.5%.

[0116] Comparative Example 4

[0117] 1) Preparation of magnesium-aluminum matrix material (catalytic cracking aid)

[0118] Take 161 grams of pseudoboehmite, add 239 grams of deionized water, add 15 grams of nitric acid with a concentration of 65% to 68% under continuous stirring, heat to 60°C for 1 hour, obtain a pseudoboehmite slurry after peptization;

[0119] Take 80 grams of magnesium oxide, add 187 grams of deionized water, mix uniformly to obtain a magnesium oxide slurry; add the magnesium oxide slurry to the above pseudoboehmite slurry, then add 9 grams of cetyltrimethylammonium chloride, beat and mix and stir for 60 minutes to obtain a magnesium-aluminum colloid slurry;

[0120] Transfer the above magnesium-aluminum colloid slurry to a crystallization reactor for crystallization reaction, react at 70°C for 5 hours to obtain a magnesium-aluminum matrix material. In the material, m(magnesium oxide):m(alumina) = 0.8:1.

[0121] (2) Preparation of catalyst

[0122] Take 1119 grams of erionite, add 3904 grams of deionized water, add 318 grams of hydrochloric acid with a concentration of 36% to 38% under continuous stirring, heat to 70°C and continue stirring for 90 minutes to obtain a modified clay; then add 968 grams of pseudoboehmite, at this time the pH of the system is 1.8, stir for 60 minutes; add 960 grams of the magnesium-aluminum matrix material slurry prepared in step (1), then add 204 grams of HRSY-1 molecular sieve, 28 grams of yttrium nitrate and 500 grams of deionized water, mix and stir uniformly to obtain a slurry, spray dry at an inlet temperature of 420°C and an outlet temperature of 180°C, solidify and calcine at 450°C for 1 hour, then take 500 grams of the solidified and calcined microspheres, wash with a solution of 2000 grams of deionized water and 200 grams of ammonium chloride at 70°C for 30 minutes, filter and dry to obtain a catalytic cracking catalyst. Denoted as D4, the reaction performance is shown in Table 1.

[0123] In the catalytic cracking catalyst prepared in this example, the molecular sieve, magnesium-aluminum matrix material and modified clay are based on dry basis, the inorganic oxide binder and rare earth additive are based on oxide, and m(molecular sieve):m(inorganic oxide binder):m(rare earth additive):m(magnesium-aluminum matrix material):m(modified clay)=10%:30%:1%:12%:47%.

[0124] Evaluation of the catalyst:

[0125] The elemental content in the catalyst was determined by X-ray fluorescence analysis.

[0126] The reaction performance of the catalytic cracking catalyst was evaluated by ACE. The catalyst sample was placed in the reactor of the ACE experiment, the reaction temperature was 530°C, the regeneration temperature was 685°C, the feed amount was 1.80g, the cold trap temperature was -13.5°C, and the agent oil ratio was 5.0. The product distribution and conversion rate after reaction were analyzed and calculated.

[0127] According to the heavy oil conversion rate, the selectivity of the catalyst to diesel in the catalytic cracking reaction was expressed by the following mathematical formula:

[0128] DI=(diesel yield / heavy oil yield)×(diesel yield / coke yield)

[0129] The larger the DI, the better the diesel selectivity of the catalyst.

[0130] Table 1 Catalyst ACE evaluation results

[0131] catalyst S1 S2 S3 S4 S5 S6 S7 D1 D2 D3 D4 coke 5.36 5.02 4.85 4.51 4.21 4.36 4.75 5.68 5.86 5.47 5.71 dry gas 2.54 2.35 2.21 2.15 2.02 2.87 2.21 2.78 2.85 2.56 2.58 gasoline 37.82 32.5 30.31 29.01 23.43 28.89 28.56 39.25 32.2 24 24.1 diesel 25.06 27.85 29.24 30.25 35.21 30.24 30.12 22.29 20.23 20.35 19.25 heavy oil 20.14 23.54 25.41 26.57 28.62 26.15 26.85 20.14 30.35 40.21 41.21 LPG 9.08 8.74 7.98 7.51 6.51 7.49 7.51 9.86 8.51 7.41 7.15 100 100 100 100 100 100 100 100 100 100 100 conversion rate 54.8 48.61 45.35 43.18 36.17 43.61 43.03 57.57 49.42 39.44 39.54 DI 5.818 6.564 6.938 7.636 10.289 8.021 7.113 4.343 2.301 1.883 1.575

[0132] From the data in the above table, S1-S7 all show high diesel yield and low coke yield, maintaining excellent coke selectivity (coke selectivity = coke yield / conversion) and diesel selectivity (diesel selectivity = diesel yield / heavy oil yield) x (diesel yield / coke yield).

[0133] In the preparation of Comparative Example 1, no magnesium-aluminum matrix material was introduced, and although the conversion rate was high, the diesel yield was low and the coke yield was high, and no high diesel selectivity was shown. In Comparative Example 2, compared with Comparative Example 1, magnesium chloride was introduced during preparation, but the alkali metal magnesium neutralized part of the acid centers of the catalyst, resulting in a decrease in conversion rate. In Comparative Examples 3 and 4, the magnesium-aluminum matrix material showed similar properties to the free-state magnesium component, and a large number of acid centers of the catalyst were neutralized, further reducing the conversion rate.

[0134] The above examples are typical examples listed to illustrate the technical solutions of the present application, and the protection scope of the present application is subject to the protection scope of the claims and the invention content, and is not limited by the described embodiments. Simple replacement or changes to the present application are still within the protection scope of the present application.

Claims

1. A process for the preparation of a catalytic cracking aid for reducing the yield of coke and for maximizing the yield of diesel, characterized in that, The method comprises the following steps: The pseudo-boehmite and deionized water are mixed, and then an acidic substance is added for peptization treatment to obtain a pseudo-boehmite slurry; The pseudo-boehmite slurry and a magnesium oxide slurry are mixed, and then a surfactant is added for crystallization reaction to obtain the catalytic cracking aid for reducing coke yield and increasing diesel production; The weight ratio of the pseudo-boehmite to the magnesium oxide slurry is (0.2-0.8):1, based on dry basis of aluminum oxide and magnesium oxide; The crystallization reaction is performed at a temperature of 50-95 ℃ for 10-72 h; The mass ratio of the catalytic cracking aid on dry basis to the surfactant is 1:0.01-0.05; The mass ratio of the pseudo-boehmite to the acidic substance is 0.05-0.25, based on dry basis of aluminum oxide; The peptization treatment is performed at a temperature of 40-80 ℃ for 1-3 h; The surfactant is hexadecyl trimethyl ammonium bromide or hexadecyl trimethyl ammonium chloride; The acidic substance is selected from one or more of hydrochloric acid, nitric acid, formic acid and acetic acid; The crystallization reaction is performed in any one of static and dynamic modes.

2. The production method according to claim 1, wherein The solid content of the pseudo-boehmite slurry is 0.15-0.25; and / or The magnesium oxide slurry is a mixed slurry of magnesium oxide and water, and the solid content of the magnesium oxide slurry is 0.2-0.

4.

3. A catalytic cracking catalyst characterized by, The catalytic cracking catalyst comprises 5wt%-25wt% of a molecular sieve on dry basis, 25wt%-40wt% of an inorganic oxide binder in terms of oxide, 0-3wt% of a rare earth additive in terms of oxide, 5wt%-15wt% of a magnesium-aluminum matrix material on dry basis and 30wt%-50wt% of modified clay, based on the total mass of the catalytic cracking catalyst being 100%. The magnesium-aluminum matrix material is the catalytic cracking aid for reducing coke yield and increasing diesel production prepared by the method of claim 1 or 2.

4. The catalytic cracking catalyst of claim 3, wherein the zeolite is a ZSM-5 zeolite. The molecular sieve is selected from a Y-type molecular sieve or a modified Y-type molecular sieve, and the modified Y-type molecular sieve is selected from a REUSY molecular sieve.

5. The catalytic cracking catalyst of claim 3 wherein the zeolite is a ZSM-5 zeolite. The modified clay is an acid-modified clay, and the clay is selected from one or more of kaolin, halloysite, montmorillonite, sepiolite, hydrotalcite and rectorite; and / or The rare earth additive is a water-soluble rare earth compound; and / or The inorganic oxide binder is one or more of an aluminum sol, a silicon sol, pseudo-boehmite and a silicon-aluminum sol.

6. The catalytic cracking catalyst of claim 5 wherein, The rare earth additive is one or more of chloride or nitrate of lanthanum, cerium, praseodymium, neodymium and yttrium.

7. A process for the preparation of a catalytic cracking catalyst as claimed in any one of claims 3 to 6, characterized in that, The method comprises the following steps: 1) adding an inorganic oxide binder to modified clay and controlling the pH of the system to be 1-3, and then adding a magnesium-aluminum matrix material and a molecular sieve to form a slurry; 2) performing spray drying and calcination solidification on the slurry to obtain a solidified catalyst; After washing, the catalytic cracking catalyst is obtained.

8. The production method according to claim 7, wherein In the process of forming the slurry in step 1), a step of adding a rare earth additive is further included.

9. The production method according to claim 7, wherein The calcination solidification is performed at a temperature of 300-600 ℃ for 0.5-2 h; The washing is performed using an aqueous ammonium chloride solution at a temperature of 30-90°C.

10. The production method according to claim 9, wherein The mass ratio of the solidified catalyst to the aqueous ammonium chloride solution is 1:(2-10), and the mass ratio of ammonium chloride to water in the aqueous ammonium chloride solution is (1-10):100.