A method for preparing an FCC aid for improving gasoline octane and sulfur transfer capacity

Abstract

The present application belongs to the field of FCC catalyst additive technology in petroleum chemical industry, and particularly relates to a preparation method of an FCC additive for improving gasoline octane number and sulfur transfer capacity. A magnesium source aqueous solution, a manganese source aqueous solution and a sodium metaaluminate aqueous solution are mixed and reacted to form a gel, a non-ionic polymer compound is added, the gel system is heated and aged, filtered, and the filter cake is purified, dewatered and calcined to obtain a porous magnesium-manganese-aluminum material; the porous magnesium-manganese-aluminum material is mixed and pulped with ZSM-5 molecular sieve, a binder is added, spray dried, calcined, aged in hot water, then dried and calcined again to obtain the FCC additive for improving gasoline octane number and sulfur transfer capacity.

Description

Technical Field

[0001] This invention belongs to the field of FCC catalyst additive technology in petrochemicals, and specifically relates to a method for preparing an FCC additive that improves the octane number and sulfur transfer capacity of gasoline. Background Technology

[0002] Catalytic cracking (FCC process) is one of the most commonly used methods for heavy oil conversion. Specifically, it involves the cracking of heavy oil into cracked gas, gasoline, and diesel under high temperature and the action of a catalyst. This process involves a series of reactions, including decomposition, isomerization, hydrogen transfer, aromatization, condensation, and coking. Catalytic cracking catalysts (FCC catalysts) mainly consist of a matrix and molecular sieves. The matrix accounts for approximately 65% ​​of the FCC catalyst and has two main functions: first, it acts as a support for the molecular sieves, improving their dispersibility and ensuring good catalyst wear resistance; second, the pre-cracking of large heavy oil molecules takes place on the matrix.

[0003] Besides achieving higher octane ratings for gasoline, another major task in gasoline production is to make it cleaner. Since January 1, 2010, low-olefin environmentally friendly gasoline has been fully launched nationwide. In the process of making gasoline cleaner, controlling the olefin content in gasoline and gasoline hydrodesulfurization will lead to a loss of octane number, and the contradiction of octane number shortage will become more prominent.

[0004] Due to the high proportion of FCC gasoline in gasoline blends in my country's gasoline production, further increasing the octane rating of FCC gasoline is an essential path for upgrading gasoline products. There are various methods to increase the octane rating of FCC gasoline, such as using octane-enhancing additives or high-octane cracking catalysts, optimizing the composition of catalytic cracking feedstocks, and changing the operating conditions of FCC units. Among these, using additives containing molecular sieves with an MFI structure is one of the effective ways to quickly increase the octane rating of FCC gasoline. The main active component for increasing gasoline octane rating is a molecular sieve with an MFI structure, which is more effective in additives than in the main agent. Furthermore, since one additive can be compounded with different main agents to meet the product distribution needs of different users, it offers greater flexibility. Therefore, for most catalytic cracking processes, using additives with MFI structure zeolites is an effective technical approach to increase octane rating. However, current measures still have the following shortcomings:

[0005] Zeolite molecular sieves undergo metal or non-metal modification, calcination, and other treatments. The molecular sieve modification process is complex, and the modified molecular sieves have the problem of agglomeration and hardness. They also need to be ground to reduce their particle size before they can be used in the preparation of additives. Otherwise, it will not be conducive to the anti-wear performance of the additives.

[0006] The aluminum phosphate used in the preparation of catalytic cracking additives has a high phosphorus and aluminum concentration during the preparation of its sol, which may lead to colloidal instability and gelation, which is not conducive to the smooth production of the additives. On the other hand, if pre-prepared aluminum phosphate is used, there are often problems with small pore volume and large bulk density, which are not conducive to fluidization, mass transfer and coking.

[0007] Some additives increase the octane rating of gasoline, but also significantly increase the yield of liquefied petroleum gas (LPG). However, for refineries where the recovery and utilization of LPG are limited, additives are required to increase the octane rating of gasoline while not significantly increasing the yield of LPG.

[0008] Furthermore, the desulfurization capacity of most desulfurization additives does not meet national standards, and their production and use are not environmentally friendly. In particular, most of the additives currently used are single-function, and to achieve two or more functions, the amount of additive used will increase exponentially, which is unfavorable from both an economic and environmental perspective.

[0009] Therefore, despite recent advancements in catalytic cracking additives for increasing gasoline octane rating, further research is needed to develop new technologies for preparing multifunctional additives that are simple and feasible to produce, environmentally friendly and economical to maximize gasoline octane rating, and to reduce the difficulty of additive production, meet the requirements of increasing gasoline octane rating, achieving multifunctionality of additives, and ensuring smooth actual production. Summary of the Invention

[0010] To address the aforementioned technical problems of existing octane-increasing additives, such as limited octane number improvement, unsatisfactory desulfurization and sulfur reduction functions, limited functionality, and cumbersome preparation methods, this invention provides a method for preparing an FCC additive that improves gasoline octane number and sulfur transfer capability.

[0011] (1) Mix the aqueous solutions of magnesium source, manganese source, and sodium aluminate to form a gel. Add a non-ionic polymer compound to the gel system and disperse it. Heat the gel system to 50-100℃ and keep it at that temperature for 1-24 hours. Filter the gel, clean and remove impurities from the filter cake, dry it, and calcine it at 400-650℃ for 0.5-3 hours to obtain porous magnesium-manganese-aluminum material.

[0012] (2) The porous magnesium manganese aluminum material obtained in step (1) and ZSM-5 molecular sieve are added to water at a weight ratio of 20-60:10-50 and mixed thoroughly. Then, a binder is added and dispersed thoroughly. The mixture is then spray-dried to obtain microsphere solids. The obtained microsphere solids are calcined at 400-600℃ and cooled. They are then aged in hot water, dried, and calcined at 400-600℃ to obtain FCC additives.

[0013] As a preferred option: in step (1), the magnesium source, manganese source, and sodium aluminate are respectively 10-70 parts by weight of anhydrous oxides of Al2O3, 20-70 parts by weight of MgO, and 8-22 parts by weight of MnO.

[0014] As a preferred embodiment: In step (1), after adjusting the pH of the resulting gelling system to 8-11 with ammonia, a nonionic polymer compound is added to it.

[0015] Furthermore: the nonionic polymer is polyvinylpyrrolidone (PVP).

[0016] As a preferred option, the purification and impurity removal in step (1) involves treating the filter cake with an ammonium salt solution via ion exchange, followed by thorough rinsing with clean water, so that the sodium ions in the filter cake, calculated as Na2O, do not exceed 0.2% by weight.

[0017] Preferably, in step (1), the product is ground to D after calcination. 90 ≤10μm, as a porous magnesium manganese aluminum material.

[0018] As a preferred option, in step (2), the silicon-to-aluminum ratio of the ZSM-5 molecular sieve is 100 to 500.

[0019] Preferably, in step (2), the adhesive comprises 10 to 40 parts by weight of a phosphorus-based adhesive and 1 to 5 parts by weight of sodium silicate, calculated as silica.

[0020] Furthermore: the phosphorus-based adhesive includes 7 to 25 parts by weight of aluminum sol based on alumina and 3 to 15 parts by weight of ammonium dihydrogen phosphate based on P2O5.

[0021] As a preferred option, in step (2), the microsphere solid is calcined at 400-600°C for 1-4 hours.

[0022] As a preferred option: in step (2), the hot water temperature is 50-100℃ and the aging treatment time is 1-5 hours.

[0023] This solution also provides an FCC additive that improves the octane number and sulfur transfer capability of gasoline, obtained by the above preparation method.

[0024] The beneficial effects of this invention are as follows:

[0025] Firstly, this scheme introduces both magnesium oxide and manganese oxide into the additives. During the catalytic cracking process, sulfur dioxide generated in the FCC fluidized bed is partially converted to manganese sulfate and partially to sulfur trioxide under the catalytic action of manganese oxide. The sulfur trioxide then combines with magnesium oxide to form magnesium sulfate. The resulting sulfate enters the reactor of the unit and is reduced to hydrogen sulfide. After separation, the catalyst enters the regenerator for coking and activation. The hydrogen sulfide, along with the dry gas, then enters the desulfurization unit for further conversion into elemental sulfur for recovery. Therefore, the more hydrogen sulfide enters the dry gas, the stronger the sulfur transfer capacity. It is evident that this scheme, through the different binding mechanisms between sulfur components and the two metal oxides, achieves a more complete conversion of sulfur elements in the feedstock into sulfates. Further treatment then achieves desulfurization, reducing the possibility of some sulfur components dissolving into gasoline and diesel fuel and being emitted into the air through flue gas.

[0026] In this scheme, sodium aluminate is used as the aluminum source. The composite oxide generated by sodium aluminate, magnesium source, and manganese source has a magnesium-aluminum spinel crystal phase structure, which is more stable and robust. This also helps to maintain the stability of the increased pore size and pore volume of the material due to the introduction of nonionic polymer compounds. Therefore, it can more effectively contact and adsorb the feedstock oil, thereby improving the processing efficiency of the feedstock oil. At the same time, the introduction of porous magnesium-manganese-aluminum material also increases the number of active sites on the FCC additive, thereby better cooperating with the catalyst and improving the cracking, isomerization, and aromatization capabilities of the feedstock oil, thus increasing the octane number.

[0027] PVP is a nonionic polymer compound, the most distinctive and extensively studied fine chemical among N-vinylamide polymers. PVP is soluble in water and most organic solvents, exhibits low toxicity, and has good physiological compatibility. In this composite material, the nonionic polymer PVP demonstrates a certain adhesive effect, further enabling the composite molding of porous magnesium-manganese-aluminum materials with ZSM-5 molecular sieves and binders to maintain the stability of the molded FCC additive composite particles without the introduction of any carrier, and also increasing the proportion of effective components in the FCC additive. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] The preparation method of the FCC additive that improves the octane number and sulfur transfer capacity of gasoline in this scheme is as follows:

[0030] (1) Based on 10-70 parts by weight of Al2O3, 20-70 parts by weight of MgO, and 8-22 parts by weight of MnO, the aqueous solutions of magnesium source, manganese source, and sodium aluminate are mixed and reacted at room temperature (25°C, the same below) to form a gel. After adjusting the pH of the resulting gel system to 8-11 with ammonia, PVP is added to the gel system and dispersed. The gel system is then heated to 50-100°C and aged for 1-24 hours. After filtration, the resulting filter cake is subjected to ion exchange treatment with ammonium salt solution and then rinsed thoroughly with water to ensure that the sodium ion content in the filter cake, calculated as Na2O, does not exceed 0.2% by weight. The filter cake is then dried and calcined at 400-650°C for 0.5-3 hours. The product is then ground to D. 90 ≤10μm, as a porous magnesium-manganese-aluminum material, the specific surface area of ​​porous magnesium-manganese-aluminum materials is 70~200m². 2 / g, pore volume 0.2~0.9cm 2 / g, with an average pore size of 10–25 nm;

[0031] (2) Add 20-60 parts by weight of the porous magnesium manganese aluminum material obtained in step (1) and 10-50 parts by weight of ZSM-5 molecular sieve with a silicon-to-aluminum ratio of 100-500 to water and mix thoroughly. Then add 1-5 parts by weight of sodium silicate (based on silicon dioxide) and 10-40 parts by weight of phosphorus-based binder (7-25 parts by weight of aluminum sol (based on alumina) and 3-15 parts by weight of ammonium dihydrogen phosphate (based on P2O5)) and disperse thoroughly. Spray dry to obtain microsphere solids. After calcining the obtained microsphere solids at 400-600°C for 1-4 hours, cool them and age them in hot water at 50-100°C for 1-5 hours. Then dry the microsphere solids and calcine them at 400-600°C for 1-4 hours to obtain FCC additives.

[0032] Example 1

[0033] (1) Preparation of porous magnesium-manganese-aluminum materials

[0034] 1 L of a 90 g / L MgSO4 aqueous solution, 250 mL of a 90 g / L MnO2 aqueous solution (MnSO4), and 900 mL of a 100 g / L Al2O3 aqueous solution (caustic ratio 2.5) were mixed and reacted at room temperature to form a gel. The pH of the resulting gel system was adjusted to 10 with ammonia. Then, 100 mL of a 50 g / L PVP-K12 solution was added to the gel system. (PVP is conventionally represented by its K value based on its average molecular weight. Different K values ​​represent different average molecular weight ranges for PVP; for example, PVP K12 represents a K value of 10.2–13.8 and a molecular weight of 3000–7000, denoted as PVP-K12. Different K values ​​of PVP are used...) The size and quantity of pores generated during material preparation are related to the process. (The same applies below) After dispersing the aqueous solution, the gelling system was heated to 65℃ and aged for 5 hours. After filtration, the resulting filter cake was washed with a 60℃ NH4Cl aqueous solution to remove sodium ions through ion exchange. The weight ratio of filter cake:NH4Cl:H2O (the solvent for NH4Cl) was 1:0.5:10. Ion exchange washing was repeated three times, each time for 15 minutes. After ion exchange, the filter cake was rinsed with 10 times its weight of 60℃ water, dried at 120℃ for 1 hour, and then calcined at 550℃ for 2 hours. Analysis showed that the sodium ions in the filter cake, calculated as Na2O, accounted for 0.19% by weight. The filter cake was then mechanically ground to D... 90 It is a 9μm powder material, used as a porous magnesium-manganese-aluminum material A-1;

[0035] (2) Preparation of FCC additives

[0036] 35 parts by weight of the porous magnesium manganese aluminum material obtained in step (1) and 45 parts by weight of ZSM-5 molecular sieve with a silicon-to-aluminum ratio of 200 were added to 45 parts by weight of water and mixed thoroughly. Then, 3 parts by weight of sodium silicate (based on silica) were added and mixed thoroughly. The pH of the mixture was adjusted to 4.0 with dilute hydrochloric acid. Then, 8 parts by weight of aluminum sol (based on alumina) and 9 parts by weight of ammonium dihydrogen phosphate (based on P2O5) were added. After stirring thoroughly, the mixture was spray-dried to obtain microsphere solids. The obtained microsphere solids were calcined at 550°C for 1 hour, naturally cooled, and aged in hot water at 60°C for 2 hours. Then, the microsphere solids were dried at 120°C for 1 hour and calcined at 550°C for 1 hour to obtain FCC additive C-1.

[0037] Example 2

[0038] (1) Preparation of porous magnesium-manganese-aluminum materials

[0039] 950 mL of a 100 g / L MgSO4 aqueous solution, 200 mL of a 110 g / L MnO MnSO4 aqueous solution, and 1 L of a 100 g / L Al2O3 aqueous solution with a caustic ratio of 2.5 were mixed and reacted at room temperature to form a gel. The pH of the resulting gel system was adjusted to 9 with ammonia. Then, 200 mL of a 30 g / L PVP-K14 aqueous solution was added and dispersed. The gel system was then heated to 70°C and aged for 4 hours. After filtration, the solution was treated with NH4+ at 60°C. The obtained filter cake was washed with NH4Cl aqueous solution to remove sodium ions by ion exchange. The weight ratio of filter cake:NH4Cl:H2O (the solvent of NH4Cl) was 1:0.7:15. The ion exchange washing was repeated 3 times, with each exchange lasting 12 minutes. After ion exchange, the filter cake was rinsed with 15 times its weight of 60°C water, dried at 120°C for 1 hour, and then calcined at 600°C for 2 hours. The sodium ion content in the filter cake at this point was found to be 0.17% by weight (based on Na2O). The filter cake was then mechanically ground to D... 90 It is a 9μm powder material, used as a porous magnesium-manganese-aluminum material A-2;

[0040] (2) Preparation of FCC additives

[0041] 40 parts by weight of the porous magnesium manganese aluminum material obtained in step (1) and 40 parts by weight of ZSM-5 molecular sieve with a silicon-to-aluminum ratio of 300 were added to 50 parts by weight of water and mixed thoroughly. Then, 4 parts by weight of sodium silicate (based on silica) were added and mixed thoroughly. The pH of the mixture was adjusted to 5.0 with dilute hydrochloric acid. Then, 10 parts by weight of aluminum sol (based on alumina) and 10 parts by weight of ammonium dihydrogen phosphate (based on P2O5) were added. After stirring thoroughly, the mixture was spray-dried to obtain microsphere solids. The obtained microsphere solids were calcined at 600°C for 1 hour, naturally cooled, and then aged in hot water at 60°C for 2 hours. The microsphere solids were then dried at 120°C for 1 hour and calcined at 600°C for 1 hour to obtain FCC additive C-2.

[0042] Comparative Example 1

[0043] Aluminum nitrate was used instead of sodium aluminate, and all other operations were the same as in Example 1:

[0044] (1) Preparation of porous magnesium-manganese-aluminum materials

[0045] 1 L of 90 g / L MgSO4 aqueous solution, 250 mL of 90 g / L MnO aqueous solution, and 900 mL of 100 g / L Al2O3 aqueous solution were mixed and reacted at room temperature to form a gel. The pH of the resulting gel system was adjusted to 10 with ammonia. Then, 100 mL of 50 g / L PVP-K12 aqueous solution was added and dispersed. The gel system was heated to 65°C and aged for 5 hours. After filtration, the filter cake was washed with 10 times its weight of 60°C water. The filter cake was then dried at 120°C for 1 hour, calcined at 550°C for 2 hours, and finally mechanically ground to D. 90 It is a 9μm powder material, used as a porous magnesium manganese aluminum material AD-1;

[0046] (2) Preparation of FCC additives

[0047] 35 parts by weight of the porous magnesium manganese aluminum material obtained in step (1) and 45 parts by weight of ZSM-5 molecular sieve with a silicon-to-aluminum ratio of 200 were added to 45 parts by weight of water and mixed thoroughly. Then, 3 parts by weight of sodium silicate (based on silica) were added and mixed thoroughly. The pH of the mixture was adjusted to 4.0 with dilute hydrochloric acid. Then, 8 parts by weight of aluminum sol (based on alumina) and 9 parts by weight of ammonium dihydrogen phosphate (based on P2O5) were added. After stirring thoroughly, the mixture was spray-dried to obtain microsphere solids. The obtained microsphere solids were calcined at 550°C for 1 hour, naturally cooled, and aged in hot water at 60°C for 2 hours. Then, the microsphere solids were dried at 120°C for 1 hour and calcined at 550°C for 1 hour to obtain FCC additive CD-1.

[0048] Comparative Example 2

[0049] PVP was not included; all other operations are the same as in Example 1.

[0050] (1) Preparation of porous magnesium-manganese-aluminum materials

[0051] 1 L of a 90 g / L MgSO4 aqueous solution, 250 mL of a 90 g / L MnO2 aqueous solution of MnSO4, and 900 mL of a 100 g / L Al2O3 aqueous solution of sodium aluminate with a caustic ratio of 2.5 were mixed and reacted at room temperature to form a gel. The pH of the resulting gel system was adjusted to 10 with ammonia. Then, 100 mL of deionized water was added and dispersed. The gel system was heated to 65°C and aged for 5 hours. After filtration, the gel was treated with a 60°C NH4Cl aqueous solution. The filter cake was washed to remove sodium ions via ion exchange. The weight ratio of filter cake:NH4Cl:H2O (the solvent for NH4Cl) was 1:0.5:10. The ion exchange washing was repeated three times, each time for 15 minutes. After ion exchange, the filter cake was rinsed with 10 times its weight of 60°C water, dried at 120°C for 1 hour, and then calcined at 550°C for 2 hours. The sodium ion content in the filter cake at this point was found to be 0.20% by weight (based on Na2O). The filter cake was then mechanically ground to D... 90 It is a 9μm powder material used as a porous magnesium-manganese-aluminum material AD-2;

[0052] (2) Preparation of FCC additives

[0053] 35 parts by weight of the porous magnesium manganese aluminum material obtained in step (1) and 45 parts by weight of ZSM-5 molecular sieve with a silicon-to-aluminum ratio of 200 were added to 45 parts by weight of water and mixed thoroughly. Then, 3 parts by weight of sodium silicate (based on silica) were added and mixed thoroughly. The pH of the mixture was adjusted to 4.0 with dilute hydrochloric acid. Then, 8 parts by weight of aluminum sol (based on alumina) and 9 parts by weight of ammonium dihydrogen phosphate (based on P2O5) were added. After stirring thoroughly, the mixture was spray-dried to obtain microsphere solids. The obtained microsphere solids were calcined at 550°C for 1 hour, naturally cooled, and aged in hot water at 60°C for 2 hours. Then, the microsphere solids were dried at 120°C for 1 hour and calcined at 550°C for 1 hour to obtain FCC additive CD-2.

[0054] Comparative Example 3

[0055] The "MgSO4 aqueous solution" was not added, and the missing magnesium oxide was replaced with an equimolar amount of manganese oxide. All other operations were the same as in Example 1.

[0056] (1) Preparation of porous manganese aluminum materials

[0057] 840 mL of a 90 g / L MnO aqueous solution and 900 mL of a 100 g / L Al2O3 aqueous solution with a caustic ratio of 2.5 were mixed and reacted at room temperature to form a gel. The pH of the resulting gel system was adjusted to 10 with ammonia. Then, 100 mL of a 50 g / L PVP-K12 aqueous solution was added and dispersed. The gel system was then heated to 65°C and aged for 5 hours. After filtration, the filter cake was treated with a 60°C NH4Cl aqueous solution. The filter cake was washed to remove sodium ions via ion exchange. The weight ratio of filter cake to NH4Cl to H2O (the solvent for NH4Cl) was 1:0.5:10. The ion exchange washing was repeated three times, with each exchange lasting 15 minutes. After ion exchange, the filter cake was rinsed with 10 times its weight of 60°C water, dried at 120°C for 1 hour, and then calcined at 550°C for 2 hours. The sodium ion content in the filter cake at this point was found to be 0.18% by weight (based on Na2O). The filter cake was then mechanically ground to D... 90 It is a 9μm powder material, used as a porous manganese aluminum material AD-3;

[0058] (2) Preparation of FCC additives

[0059] 35 parts by weight of the porous manganese aluminum material obtained in step (1) and 45 parts by weight of ZSM-5 molecular sieve with a silicon-to-aluminum ratio of 200 were added to 45 parts by weight of water and mixed thoroughly. Then, 3 parts by weight of sodium silicate (based on silicon dioxide) were added and mixed thoroughly. The pH of the mixture was adjusted to 4.0 with dilute hydrochloric acid. Then, 8 parts by weight of aluminum sol (based on alumina) and 9 parts by weight of ammonium dihydrogen phosphate (based on P2O5) were added. After stirring thoroughly, the mixture was spray-dried to obtain microsphere solids. The obtained microsphere solids were calcined at 550°C for 1 hour, naturally cooled, and aged in hot water at 60°C for 2 hours. Then, the microsphere solids were dried at 120°C for 1 hour and calcined at 550°C for 1 hour to obtain FCC additive CD-3.

[0060] Comparative Example 4

[0061] A certain amount of clay was added during the preparation of the FCC additive, and the rest of the operations were the same as in Example 1:

[0062] (1) Preparation of porous magnesium-manganese-aluminum materials

[0063] 1 L of a 90 g / L MgSO4 aqueous solution, 250 mL of a 90 g / L MnO aqueous solution of MnSO4, and 900 mL of a 100 g / L Al2O3 aqueous solution with a caustic ratio of 2.5 were mixed and reacted at room temperature to form a gel. The pH of the resulting gel system was adjusted to 10 with ammonia. Then, 100 mL of a 50 g / L PVP-K12 aqueous solution was added and dispersed. The gel system was then heated to 65°C and aged for 5 hours. After filtration, the gel was treated with NH4+ at 60°C. The obtained filter cake was washed with Cl aqueous solution to remove sodium ions by ion exchange. The weight ratio of filter cake:NH4Cl:H2O (the solvent of NH4Cl) was 1:0.5:10. The ion exchange washing was repeated 3 times, with each exchange lasting 15 minutes. After ion exchange, the filter cake was rinsed with 10 times its weight of 60°C water, dried at 120°C for 1 hour, and then calcined at 550°C for 2 hours. The sodium ion content in the filter cake at this point was 0.19% by weight (based on Na2O). The filter cake was then mechanically ground to D... 90 It is a 9μm powder material, used as a porous magnesium-manganese-aluminum material A-1;

[0064] (2) Preparation of FCC additives

[0065] 35 parts by weight of the porous magnesium manganese aluminum material obtained in step (1) and 45 parts by weight of ZSM-5 molecular sieve with a silicon-to-aluminum ratio of 200 were added to 45 parts by weight of water and mixed thoroughly. Then, 3 parts by weight of sodium silicate and 25 parts by weight of diatomaceous earth were added and mixed thoroughly. The pH of the mixture was adjusted to 4.0 with dilute hydrochloric acid. Then, 8 parts by weight of aluminum sol and 9 parts by weight of ammonium dihydrogen phosphate were added. After stirring thoroughly, the mixture was spray-dried to obtain microsphere solids. The obtained microsphere solids were calcined at 550°C for 1 hour, naturally cooled, and aged in hot water at 60°C for 2 hours. Then, the microsphere solids were dried at 120°C for 1 hour and calcined at 550°C for 1 hour to obtain FCC additive CD-4.

[0066] Comparative Example 5

[0067] In the preparation of FCC additives, only a certain amount of kaolin is added, without the addition of porous magnesium manganese aluminum materials, and the rest of the operations are the same as in Example 1.

[0068] 35 parts by weight of kaolin and 45 parts by weight of ZSM-5 molecular sieve with a silica-alumina ratio of 200 were added to 45 parts by weight of water and thoroughly mixed and pulped. Then, 3 parts by weight of sodium silicate (based on silica) were added and thoroughly mixed. The pH of the mixture was adjusted to 4.0 with dilute hydrochloric acid. Then, 8 parts by weight of aluminum sol (based on alumina) and 9 parts by weight of ammonium dihydrogen phosphate (based on P2O5) were added. After thorough stirring, the mixture was spray-dried to obtain microsphere solids. The obtained microsphere solids were calcined at 550°C for 1 hour, naturally cooled, and then aged in hot water at 60°C for 2 hours. The microsphere solids were then dried at 120°C for 1 hour and then calcined at 550°C for 1 hour to obtain FCC additive C-5.

[0069] The pore volume and wear index of the FCC additives prepared in the above embodiments and comparative embodiments were measured respectively, as shown in Table 1:

[0070] Table 1

[0071]

[0072]

[0073] In the table above, compared with Example 1, sodium aluminate, an aluminum source, was not used in Comparative Example 1, which led to a decrease in the strength stability of the prepared porous magnesium manganese aluminum material. This resulted in a decrease in wear resistance, and the pore structure generated based on PVP also underwent local collapse and shrinkage during subsequent preparation, leading to a decrease in pore volume data.

[0074] Compared to Example 1, Example 2 did not involve pore enlargement modification via PVP, resulting in unsatisfactory final pore volume data.

[0075] Compared to Example 1, Example 3 did not introduce a magnesium source, and therefore could not synergistically generate a magnesium-aluminum spinel crystal phase structure with other metal sources, resulting in porous materials that were not wear-resistant and had significantly reduced strength and stability.

[0076] Compared with Example 4, which added some clay as a carrier based on Example 1, the mechanical wear resistance and pore properties not only did not increase, but actually declined. This fully demonstrates that the porous additive composed of porous magnesium manganese aluminum material and molecular sieve in this solution has already achieved ideal mechanical stability and pore properties.

[0077] Compared to Example 1, Example 5 did not include porous magnesium-manganese-aluminum material and was completely replaced by clay, which led to a further decline in mechanical wear resistance and a slight decrease in total pore volume. This further proves that the combination of porous magnesium-manganese-aluminum material and molecular sieve in this scheme can increase the mechanical stability and pore volume of the additive to a certain extent.

[0078] The FCC additives and FCC main catalyst LBO-16 prepared in the above embodiments and comparative embodiments were aged at 800°C under saturated steam for 10 hours. Then, each FCC additive was uniformly mixed with FCC main catalyst LBO-16 at a weight ratio of 5:95 to form a catalytic packing. The catalytic cracking performance of the packing material on the feedstock was tested in a small fixed fluidized bed apparatus at 350°C and a feedstock weight hourly space velocity of 20 h⁻¹. -1 (The mass of feedstock oil in contact with a unit mass of catalytic packing per hour), the feedstock oil is provided by Sinopec Changling Refining & Chemical, and the various parameters of the feedstock oil are shown in Table 2:

[0079] Table 2

[0080]

[0081]

[0082] Pure FCC main catalyst LBO-16 without any additives was used as blank control 1, and additives prepared by directly mixing ZSM-5 molecular sieve, the raw material used in the examples and comparative examples, with the main catalyst LBO-16 at a weight ratio of 5:95 were used as blank control 2. The specific catalytic cracking results are shown in Table 3:

[0083] Table 3

[0084]

[0085] (In the table above, the sum of the weight percentages of the various catalytic cracking components is close to 100%, of which propylene is included in the liquefied petroleum gas.)

[0086] In the table above, since the pore properties of the additive in Comparative Example 1 are not as ideal as those in Example 1, and the stability of the additive is also lower than that in Example 1, the catalytic cracking efficiency and desulfurization efficiency are both lower than those of the additive in Example 1.

[0087] In contrast, in Example 2, no pore-expanding modification was performed using PVP, resulting in consistently poor pore volume. Although the additive exhibited good overall stability, the catalytic cracking efficiency and desulfurization efficiency remained consistently low.

[0088] Compared to Example 1, Example 3 lacks the introduction of metallic magnesium, which makes it unable to effectively absorb and remove sulfur trioxide, a byproduct of the reaction between sulfur substances and manganese oxides in the feedstock oil. This affects the desulfurization efficiency. In addition, the inability to form a magnesium-aluminum spinel crystal phase structure results in lower overall stability of the additive, which also affects some other aspects of the catalytic cracking effect.

[0089] Comparative Example 4 and Example 1 show that, firstly, the introduction of clay as a carrier in Comparative Example 4 does not demonstrate the contribution of clay to the dispersion of the active ingredients in the additives; at the same time, the overall content of active ingredients in the additives decreases accordingly, and the pore performance decreases compared to Example 1, resulting in a certain degree of decline in the effectiveness of the additives.

[0090] In Comparative Example 5, after using clay as a carrier to disperse the molecular sieve additive of blank control 2, the effect was only a very limited improvement compared to blank control 2. This is partly due to the decrease in the content of effective molecular sieve components in the overall additive, but more so due to the limitations of clay material.

[0091] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for preparing an FCC additive that improves the octane number and sulfur transfer capability of gasoline, characterized in that: The preparation method is as follows: (1) Mix the aqueous solutions of magnesium source, manganese source, and sodium aluminate to form a gel. Add a non-ionic polymer compound to the gel system and disperse it. Heat the gel system to 50-100℃ and keep it at that temperature for 1-24 hours. Filter the gel, clean and remove impurities from the filter cake, dry it, and calcine it at 400-650℃ for 0.5-3 hours to obtain porous magnesium-manganese-aluminum material. (2) The porous magnesium-manganese-aluminum material obtained in step (1) and ZSM-5 molecular sieve are added to water at a weight ratio of 20-60:10-50 and thoroughly mixed and slurried. Then, a binder is added and the mixture is fully dispersed. After spray drying, microsphere solids are obtained. The obtained microsphere solids are calcined at 400-600℃, cooled, and then aged in hot water. After drying, the microsphere solids are calcined again at 400-600℃ to obtain the FCC additive. In step (1), the pH value of the resulting gelling system is adjusted to 8-11 with ammonia water, and then the nonionic polymer compound is added to it. In step (2), the silicon-aluminum ratio of the ZSM-5 molecular sieve is 100 to 500; The nonionic polymer compound is polyvinylpyrrolidone; In step (1), the purification and impurity removal involves treating the filter cake with an ammonium salt solution via ion exchange, followed by thorough rinsing with clean water, so that the sodium ions in the filter cake, calculated as Na2O, do not exceed 0.2% by weight. The adhesive comprises 10 to 40 parts by weight of phosphorus-based adhesive and 1 to 5 parts by weight of sodium silicate, calculated as silicon dioxide.

2. The preparation method of the FCC additive for improving gasoline octane number and sulfur transfer capability as described in claim 1, characterized in that: In step (1), the magnesium source, the manganese source, and the sodium aluminate are respectively 20-70 parts by weight of anhydrous oxides of MgO, 8-22 parts by weight of MnO, and 10-70 parts by weight of Al2O3.

3. The preparation method of the FCC additive for improving gasoline octane number and sulfur transfer capability as described in claim 2, characterized in that: The phosphorus-based adhesive comprises 7 to 25 parts by weight of aluminum sol (calculated as alumina) and 3 to 15 parts by weight of ammonium dihydrogen phosphate (calculated as P2O5).

4. The method for preparing the FCC additive for improving gasoline octane number and sulfur transfer capability as described in claim 1, characterized in that: In step (2), the microsphere solid is calcined at 400-600°C for 1-4 hours.

5. The preparation method of the FCC additive for improving gasoline octane number and sulfur transfer capability as described in claim 1, characterized in that: In step (2), the hot water temperature is 50-100℃, and the aging treatment time is 1-5 hours.

6. An FCC additive for improving the octane number and sulfur transfer capability of gasoline, prepared by the method according to any one of claims 1 to 5.

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