CN105013526B - A kind of assistant for calalytic cracking for improving low-carbon olefin concentration and preparation method thereof - Google Patents

Abstract

The invention discloses a catalytic cracking additive for increasing the concentration of low-carbon olefins and a preparation method thereof. The auxiliary agent includes boron-modified phosphorus- and metal-containing β molecular sieves, a first binder, a second binder and optional second clay; wherein, the boron-modified phosphorus- and metal-containing β molecular sieves In the β molecular sieve containing phosphorus and metal, the boron content is 0.5-10% by weight as B2O3 _; the phosphorus content is _0.5-10 % by weight as _P2O5 , and the metal content is as metal _oxide is 0.5-10% by weight, and in the ²⁷ Al MAS NMR spectrogram of the β molecular sieve containing phosphorus and metal, the chemical shift is the peak area of the resonance signal of 40 ± 3ppm and the chemical shift is the ratio of the resonance signal of 54 ± 3ppm The peak area ratio is 1 or more. The catalytic cracking additive is applied to the catalytic cracking of petroleum hydrocarbons, which can increase the concentration of isobutene in the liquefied gas and reduce the output of coke.

Description

Catalytic cracking additive for increasing concentration of low-carbon olefins and preparation method thereof

technical field

The present invention relates to a catalytic cracking aid for increasing the concentration of low-carbon olefins and a preparation method thereof. Further, the present invention relates to a catalytic cracking aid comprising a boron-modified phosphorus- and metal-containing β molecular sieve and the preparation of the catalytic cracking aid. The method of cracking aids.

Background technique

Low-carbon olefins are important organic chemical raw materials, and the world's demand for low-carbon olefins is increasing year by year. Fluid catalytic cracking is one of the important processes for producing low-carbon olefins. For most catalytic cracking units, adding additives is an effective technical way to increase the production of low-carbon olefins. However, the prior art has no obvious effect on increasing the concentration of isobutene in liquefied gas. From the perspective of isobutene formation and reaction chemistry in the FCC process, β molecular sieve (also known as β zeolite, beta molecular sieve) is an effective active component. The main problem of β molecular sieve in use is that on the one hand, its structure is easily damaged during the process of removing its template agent, and on the other hand, it is easy to dealuminate during the reaction process, so the activity stability is poor.

Early patents disclosed some cracking catalysts or additives containing zeolite beta, which can increase the octane number of gasoline and increase the production of light olefins and liquefied gas, such as US4740292, US4898846, US4911823 and WO95026533. Some of the beta zeolites used in these patents are emphasized as low-sodium hydrogen zeolites, and some are emphasized as high-silicon-aluminum ratio zeolites. β with a high silicon-aluminum ratio can be synthesized directly, or obtained by hydrothermal treatment or acid treatment.

US4837396 discloses a catalyst containing Beta zeolite and Y zeolite, and containing metal ion compound as a stabilizer to improve the hydrothermal stability and mechanical strength of the catalyst. The stabilizer can be [Al ₂ (OH) ₅ Cl] _x , or Al ₃ Zr(OH) ₉ Cl ₄ . The stabilizer can directly interact with the β zeolite, or it can be added during the preparation of the catalyst.

US6355591 discloses a catalytic cracking additive containing 4-20% of aluminum phosphate, 1-40% of ZSM-5, β and mixtures thereof, and 40-90% of clay, which can increase the output of LPG. The preparation method of aluminum phosphate is: add concentrated phosphoric acid to dilute in deionized water, add aluminum powder to dissolve, wherein the molar ratio of Al to PO ₄ is 1:3, and the pH is less than 2.0. The prepared aluminum phosphate and kaolin are evenly mixed, then mixed into the molecular sieve slurry, and finally sprayed into shape. According to the patent claims, the additive does not contain other binders and other inorganic oxides except aluminum phosphate. In addition, the preparation method and properties of additives containing zeolite beta are not given in the examples of this patent.

Propose a kind of modification method of β molecular sieve among CN1043450A, this method is to extract part of framework aluminum with acid after Naβ molecular sieve is roasted, then carry out potassium exchange to make zeolite potassium content be 0.5-2.5% by weight, after drying, roasting, use Soak in near-neutral phosphate buffer solution including potassium hydrogen phosphate-potassium dihydrogen phosphate, hypophosphorous acid-potassium hypophosphite, phosphorous acid-potassium phosphite for 4-10 hours at room temperature, wash or not wash as appropriate The phosphorus content on the zeolite is 0.01-0.5% by weight, and then dried and calcined; the β molecular sieve modified by this method is suitable as a hydrocarbon processing catalyst involving hydroisomerization reaction.

CN1179994A proposes a method for modifying β molecular sieves. In this method, Na β molecular sieves are exchanged with ammonium ions and the Na ₂ O content on the zeolite is less than 0.1% by weight; Aluminum, so that its silicon-aluminum ratio is greater than 50; the above-mentioned dealuminated β molecular sieve is evenly mixed with phosphoric acid or phosphate, and then dried, so that the amount of P2O5 on the gained zeolite is 2-5% by weight; finally, it is mixed with 450-650°C hydrothermal roasting for 0.5-4 hours. When the β molecular sieve modified by the method is used for the cracking reaction of hydrocarbons, a higher yield of olefins, especially isomeric olefins, and a lower yield of coke can be obtained.

CN1872685A discloses a modified β molecular sieve, the anhydrous chemical expression of the modified β molecular sieve is expressed as

(0-0.3)Na ₂ O·(0.5-10)Al ₂ O ₃ ·(1.3-10)P ₂ O ₅ ·(0.7-15)M _x O _y ·(70-97)SiO ₂ , where M One selected from Fe, Co, Ni, Cu, Mn, Zn and Sn. The zeolite is used in catalytic cracking and can be used as an active component of a catalyst or an auxiliary agent.

However, the concentration of isobutene in the liquefied gas obtained by catalytic cracking using the above additives is not high, and the coke yield is high at the same time.

Contents of the invention

The purpose of the present invention is to solve the problem of low concentration of isobutene in the liquefied gas obtained by catalytic cracking and high coke yield in the prior art, to provide a catalytic cracking additive and a preparation method thereof for increasing the concentration of low-carbon olefins, The application of the additive in the catalytic cracking process can increase the concentration of isobutene in the catalytic cracking liquefied gas, reduce the output of coke, and at the same time, the heavy oil conversion ability of the main catalyst will not be affected when the additive is added in a large proportion.

The present invention provides a catalytic cracking additive for increasing the concentration of low-carbon olefins, the additive comprising: boron-modified phosphorus- and metal-containing β molecular sieves, a first binding agent, a second binding agent and an optional second Clay, wherein the first binder is a phosphorus-aluminum inorganic binder containing the first clay, and the second binder is an inorganic oxide binder other than the first binder; Based on the total weight of the additive on a dry basis, the content of the boron-modified phosphorus- and metal-containing β molecular sieve is 10-75% by weight, and the content of the first binder is based on the first binder The sum of the dry weight of the aluminum component, the phosphorus component and the first clay in the agent is 3-30% by weight, the content of the second binder is 3-30% by weight in terms of oxides, and the The content of the second clay is 0-60% by weight on a dry basis; wherein, based on the total weight of the first binder on a dry basis, the first binder includes Al ₂ O ₃ 15-40% by weight of the aluminum component, 45-80% by _weight of the phosphorus component based on P ₂ O5 and 1-40% by weight of the first clay based on dry weight, and wherein the phosphorus component The weight ratio of P to Al in the aluminum component, P/Al, is 1-6:1; in the boron-modified phosphorus- and metal-containing β molecular sieve, the boron-modified phosphorus- and metal-containing β molecular sieve The total weight of the β molecular sieve is based on the total weight, and the boron content is 0.5-10% by weight in terms of B ₂ O ₃ ; in the β molecular sieve containing phosphorus and metal, the phosphorus content 0.5-10% by weight as _P2O5 , metal content as _0.5-10 % by weight as metal oxide, and in the ^27Al MAS NMR spectrum of the phosphorus- and metal-containing β molecular sieve, the chemical shift is The ratio of the peak area of the resonance signal at 40±3 ppm to the peak area of the resonance signal at the chemical shift of 54±3 ppm is 1 or more.

The present invention also provides a method for preparing catalytic cracking additives for increasing the concentration of low-carbon olefins, the method comprising: boron-modified phosphorus- and metal-containing β molecular sieves, a first binding agent, a second binding agent, any The selected phosphorus additive, the optional second clay, water and acidic liquid are mixed, and the resulting slurry is dried, molded and calcined; wherein, the first binder is a phosphorus-aluminum inorganic binder containing the first clay, The second binder is an inorganic oxide binder other than the first binder; wherein, based on the total weight of the first binder on a dry basis, the first binder _The agent comprises 15-40% by weight of aluminum component as _Al2O3 , 45-80 _% by weight of phosphorus component as _P2O5 and 1-40% by weight of the first clay based on dry basis , and wherein the weight ratio P/Al of P in the phosphorus component to Al in the aluminum component is 1-6:1, and the pH value is 1-3.5; the solid content of the first binder is 15-60 % by weight; in the boron-modified phosphorus- and metal-containing β molecular sieve, based on the total weight of the boron _- modified phosphorus- and metal _- containing β molecular sieve, the boron content is 0.5-10 wt. %; in the β molecular sieve containing phosphorus and metal, based on the total weight of the β molecular sieve containing phosphorus and metal, the phosphorus content is 0.5-10% by weight in terms of P ₂ O ₅ , and the metal content is in terms of metal oxide Calculated as 0.5-10% by weight, and in the ²⁷ Al MAS NMR spectrum of the phosphorus- and metal-containing β molecular sieve, the peak area of the resonance signal with a chemical shift of 40 ± 3 ppm is the same as that of the resonance signal with a chemical shift of 54 ± 3 ppm The ratio of the peak areas is 1 or more.

The catalytic cracking additive provided by the invention has good wear resistance and catalytic cracking performance, is used for heavy oil catalytic cracking reaction, can significantly increase the concentration of isobutene and low-carbon olefins in catalytic cracking liquefied gas, and has low coke selectivity, And when the additive is added in a large proportion, it will not affect the heavy oil conversion ability of the main catalyst. Compared with existing additives, it has higher heavy oil conversion activity, higher isobutene selectivity, higher concentration of isobutene in liquefied gas, better coke selectivity, and unexpectedly higher liquid recovery. For example, in Comparative Example 11, the industrial MLC-500 balancer was used to react at 480°C, the weight hourly space velocity was 16h-1, and the agent-oil ratio was 5. The yield of liquefied gas was 15.31% by weight, and the yield of heavy oil was 15.78% % by weight, the liquid yield was 76.69% by weight, the yield of isobutene was 1.36% by weight, the concentration of isobutene was 8.88% by weight, and the coke selectivity was 9.34% by weight. And in embodiment 34, use the auxiliary agent ZJ4 that embodiment 27 provides according to the present invention, wherein contain the beta molecular sieve A4-B of phosphorus and iron of 50% by weight of boron modification, the kaolin of 12% by weight, 24% by weight The first binder N2, 8% by weight of pseudo-boehmite and 6% by weight of alumina sol, after mixing ZJ4 with the above-mentioned MLC-500 balancer in a weight ratio of 10:90, in the same method as Comparative Example 11 Catalytic cracking reaction is carried out under conditions, the yield of liquefied gas is 18.01% by weight, the yield of heavy oil is 14.05% by weight, the yield of liquid is 78.27% by weight, the yield of isobutene is 2.32% by weight, the concentration of isobutene in the liquefied gas is 12.88% by weight, and the coke The selectivity was 9.11% by weight.

Other features and advantages of the present invention will be described in detail in the following detailed description.

detailed description

Specific embodiments of the present invention will be described in detail below. It should be understood that the specific embodiments described here are only used to illustrate and explain the present invention, and are not intended to limit the present invention.

The present invention provides a catalytic cracking additive for increasing the concentration of low-carbon olefins, the additive comprising: boron-modified phosphorus- and metal-containing β molecular sieves, a first binding agent, a second binding agent and an optional second Clay, wherein the first binder is a phosphorus-aluminum inorganic binder containing the first clay, and the second binder is an inorganic oxide binder other than the first binder; Based on the total weight of the additive on a dry basis, the content of the boron-modified phosphorus- and metal-containing β molecular sieve is 10-75% by weight, and the content of the first binder is based on the first binder The sum of the dry weight of the aluminum component, the phosphorus component and the first clay in the agent is 3-30% by weight, the content of the second binder is 3-30% by weight in terms of oxides, and the The content of the second clay is 0-60% by weight on a dry basis; wherein, based on the total weight of the first binder on a dry basis, the first binder includes Al ₂ O ₃ 15-40% by weight of the aluminum component, 45-80% by weight of the phosphorus component based on P ₂ O ₅ and 1-40% by weight of the first clay based on dry weight, and wherein the phosphorus component The weight ratio of P to Al in the aluminum component, P/Al, is 1-6:1; in the boron-modified phosphorus- and metal-containing β molecular sieve, the boron-modified phosphorus- and metal-containing β The total weight of the molecular sieve is based on the total weight of the molecular sieve, and the boron content is 0.5-10% by weight in terms _of B2O3 _; in the β molecular sieve containing phosphorus and metal, based on the total weight of the β molecular sieve containing phosphorus and metal The content is 0.5-10% by weight as P ₂ O ₅ , the metal content is 0.5-10% by weight as metal oxide, and in the ²⁷ Al MAS NMR spectrum of the phosphorus- and metal-containing β molecular sieve, the chemical shift The ratio of the peak area of the resonance signal at 40±3 ppm to the peak area of the resonance signal at the chemical shift of 54±3 ppm is 1 or more.

In the boron-modified phosphorus- and metal-containing β molecular sieve of the present invention, the phosphorus is fully coordinated with the skeleton aluminum, and the introduction of boron fully protects the skeleton aluminum, which has excellent hydrothermal stability and better product selectivity , the metal increases the selectivity of light olefins.

In the present invention, preferably, based on the total weight of the additive on a dry basis, the content of the boron-modified phosphorus- and metal-containing β molecular sieve is 20-60% by weight, and the content of the first binder is The sum of the dry basis weight of the aluminum component, the phosphorus component and the first clay in the first binder is 8-25% by weight, and the content of the second binder is 5% by oxide. -25% by weight. The content of the second clay is 10-45% by weight on a dry basis. In the present invention, the content of the boron-modified phosphorus- and metal-containing β molecular sieve is calculated on a dry basis.

In the present invention, preferably, in the boron-modified phosphorus- and metal-containing β molecular sieve, the boron content is calculated as B ₂ O ₃ based on the total weight of the boron-modified phosphorus- and metal-containing β molecular sieve 2-8% by weight.

According to the present invention, preferably, in the β molecular sieve containing phosphorus and metal, based on the total weight of the β molecular sieve containing phosphorus and metal, the phosphorus content is 3-9% by weight in terms of P ₂ O ₅ , and the metal The content is 0.5-5% by weight in terms of metal oxide, and in the ²⁷ Al MASNMR spectrum of the β molecular sieve containing phosphorus and metal, the peak area and chemical shift of the resonance signal with a chemical shift of 40±3ppm are 54±3ppm The peak area ratio of the resonance signal at 3 ppm is 2 or more.

In the ²⁷ Al MAS NMR spectrogram of the phosphorus- and metal-containing β molecular sieve of the present invention, the resonance signal with a chemical shift of 54 ± 3ppm characterizes the four-coordinated framework aluminum species, and the resonance signal with a chemical shift of 40 ± 3ppm characterizes the same as Phosphorus-coordinated framework aluminum species. More preferably, in the ²⁷ Al MAS NMR spectrum of the β molecular sieve containing phosphorus and metal, the ratio of the peak area of the resonance signal with a chemical shift of 40±3ppm to the peak area of the resonance signal with a chemical shift of 54±3ppm Such as 2-5:1.

According to the present invention, the metal contained in the phosphorus- and metal-containing β molecular sieve can help improve the selectivity of low-carbon olefins in the product during the catalytic cracking process. Preferably, the metal may be selected from at least one of Fe, Co, Ni, Cu, Mn, Zn and Sn.

According to the present invention, the composition of the first binder can be further preferred. Based _on the total weight of the first binder _on a dry basis, the first binder includes 15- 35% by weight of the aluminum component, 50-75% by weight of the phosphorus component based on P ₂ O ₅ and 8-35% by weight of the first clay based on dry weight, and wherein P in the phosphorus component and The weight ratio P/Al of Al in the aluminum component is 2-5:1.

In the present invention, the aluminum component contained in the first binder may come from an alumina source. The alumina source can be aluminum hydroxide and/or alumina that can be peptized by acid; preferably, the alumina source can be p-alumina, χ-alumina, η-alumina, γ-alumina At least one of aluminum, kappa-alumina, delta-alumina, theta-alumina, gibbsite, pyrenite, zodiasite, diaspore, boehmite and pseudoboehmite. The phosphorus component may be derived from concentrated phosphoric acid.

According to the present invention, preferably, the first clay is at least one of kaolin, sepiolite, attapulgite, retortite, montmorillonite and diatomite, preferably the first clay is retortite .

In the present invention, the second clay can be selected from at least one clay known to those skilled in the art, preferably, the second clay can be selected from kaolin, metakaolin, diatomite, sepiolite, At least one of attapulgite, montmorillonite, rectorite, halloysite, saponite, bentonite and hydrotalcite, preferably kaolin, metakaolin, diatomite, sepiolite, attapulgite, at least one of montmorillonite and rectorite.

According to the present invention, the second binder can be selected from at least one of inorganic oxides commonly used in catalytic cracking aids or catalyst substrates or binder components, for example, the second binder can be selected from At least one of pseudo-boehmite, alumina sol, silica-alumina sol and water glass; preferably, the second binder is pseudo-boehmite and/or alumina sol.

According to the present invention, preferably, based on the total weight of the auxiliary agent on a dry basis, the auxiliary agent may further contain a phosphorus additive calculated as P ₂ O ₅ in an amount of not more than 15% by weight.

In the present invention, the phosphorus additive can exist in any possible position in the auxiliary agent, such as inside the pores of the zeolite, on the surface of the zeolite, in the matrix material, or at the same time inside the pores of the zeolite, Zeolite surface and matrix materials. The phosphorus additive may exist in the form of phosphorus compounds (such as phosphorus oxides, phosphates, phosphites, alkali phosphates, acid phosphates). In the present invention, the phosphorus additive is calculated as P ₂ O ₅ , and the content thereof does not include the amount of phosphorus contained in the phosphorus- and metal-containing β molecular sieve and the first binder.

The present invention also provides a method for preparing catalytic cracking additives for increasing the concentration of low-carbon olefins, the method comprising: boron-modified phosphorus- and metal-containing β molecular sieves, a first binding agent, a second binding agent, any The selected phosphorus additive, the optional second clay, water and acidic liquid are mixed, and the resulting slurry is dried, molded and calcined; wherein, the first binder is a phosphorus-aluminum inorganic binder containing the first clay, The second binder is an inorganic oxide binder other than the first binder; wherein the first binder includes 15-40% by weight of aluminum calculated as Al ₂ O ₃ Components, 45-80% by weight of phosphorus components based on P ₂ O ₅ and 1-40% by weight of the first clay based on dry weight, and wherein P in the phosphorus component and P in the aluminum component The weight ratio P/Al of Al is 1-6:1, and the pH value is 1-3.5; the solid content of the first binder is 15-60% by weight; the boron-modified phosphorus- and metal-containing β In the molecular sieve, based on the total weight of the boron-modified phosphorus and metal-containing β molecular sieve, the boron content is 0.5-10% by weight in terms of B ₂ O ₃ ; in the phosphorus- and metal-containing β molecular sieve, the The total weight of the phosphorus-containing and metal-containing β molecular sieve is based _on the total weight, the phosphorus content is 0.5-10% by weight as _P2O5 , and the metal content is 0.5-10% by weight as metal oxides, and in the phosphorus-containing and metal In the ²⁷ Al MAS NMR spectrum of the metal β molecular sieve, the ratio of the peak area of the resonance signal with a chemical shift of 40±3ppm to the peak area of the resonance signal with a chemical shift of 54±3ppm is 1 or more.

According to the present invention, preferably, the added amount of the boron-modified phosphorous and metal-containing β molecular sieve, the first binder, the second binder and the optional second clay is such that the obtained catalytic cracking aid In the present invention, based on the total weight of the additive on a dry basis, the content of the boron-modified phosphorus- and metal-containing β molecular sieve is 10-75% by weight, and the content of the first binder is based on the first The sum of the dry weight of the aluminum component, the phosphorus component and the first clay in the binder is 3-30% by weight, and the content of the second binder is 3-30% by weight in terms of oxides, The content of the second clay is 0-60% by weight on a dry basis; preferably, based on the total weight of the additive on a dry basis, the content of the phosphorus- and metal-containing β molecular sieve is 20-60% by weight , the content of the first binder is 8-25% by weight based on the sum of the dry weight of the aluminum component, the phosphorus component and the first clay in the first binder, and the second binder is The content of the binder is 5-25% by weight based on the oxide, and the content of the second clay is 10-45% by weight based on the dry weight.

In the method for preparing catalytic cracking aids for increasing the concentration of low-carbon olefins provided by the present invention, in the process of mixing, there is no special requirement for the order of addition of each component, for example, the first binder, the second binder can be , boron-modified phosphorus and metal-containing β molecular sieves, optional second clay, optional phosphorus additives are mixed in the order of addition (the second clay and phosphorus additive can be omitted when not containing the second clay and phosphorus additive addition step).

In the present invention, the drying molding can be, for example, spray drying, and the method of spray drying is well known to those skilled in the art, and there is no special requirement in the present invention. The calcination method and conditions are well known to those skilled in the art, for example, the calcination temperature is 400-700°C, preferably 450-650°C; the calcination time is at least 0.5 hours, preferably 0.5-100 hours, More preferably 0.5-10 hours.

In the present invention, the acidic liquid can be an acid or an aqueous acid solution, and the acid can be selected from water-soluble inorganic acids and/or organic acids, preferably the acid can be hydrochloric acid, nitric acid, phosphoric acid and acetic acid at least one of; the acidic liquid is used in an amount such that the slurry has a pH value of 1-5, preferably a pH value of 1.5-4.

In the present invention, the amount of water added in step (1) is not particularly limited, as long as the carrier slurry in step (1) can be obtained. For example, water is added in such an amount that the resulting carrier slurry has a solids content of 15-50% by weight.

According to the present invention, preferably, the preparation method of the first binder includes: (1) mixing the alumina source, the first clay and water to obtain a mixture; (2) concentrating the mixture obtained in step (1) Phosphoric acid is contacted to obtain a slurry; (3) the slurry obtained in step (2) is reacted; wherein, the weight ratio of the first clay in dry basis to the alumina source in Al ₂ O ₃ is 0.025-2.66:1; The use amount of described concentrated phosphoric acid and alumina source makes the weight ratio P/Al of the P in described concentrated phosphoric acid and the Al in described alumina source be 1-6:1; The temperature of described reaction is 50-99 °C, the reaction time is 15-90min.

In the present invention, in the step (1) of the preparation method of the first binder, a mixture with a solid content of 8-45% by weight is obtained. The source of alumina is aluminum hydroxide and/or alumina which can be peptized by acid. The prepared first binder does not contain chlorine and has a pH of 1-3.5.

In the step (2) of the preparation method of the first binder of the present invention, in the P/Al, P is the weight of phosphorus in the concentrated phosphoric acid as a simple substance, and Al is the aluminum in the alumina source as a simple substance. the weight of. In a preferred embodiment of the present invention, the alumina source, the first clay and concentrated phosphoric acid are used in amounts such that the obtained first binder includes 15-40% by weight, preferably 15-35% by weight of _Al2O3 as an aluminum source, 45-80% by weight, preferably 50-75 _% by weight of _P2O5 , and 1-40% by weight, preferably 8-35% by weight of the first clay _on a dry basis, wherein The weight ratio of P/Al is 1-6:1, preferably 2-5:1.

According to the present invention, preferably, the alumina source can be ρ-alumina, χ-alumina, η-alumina, γ-alumina, κ-alumina, δ-alumina, θ-alumina, At least one of gibbsite, pyrenite, zodiasite, diaspore, boehmite and pseudoboehmite.

In the present invention, the first clay may be at least one of kaolin, sepiolite, attapulgite, rector's clay, montmorillonite and diatomite, preferably rector's clay.

In the present invention, the concentrated phosphoric acid may have a concentration of 60-98% by weight, preferably 75-90% by weight. The feeding rate of the concentrated phosphoric acid is preferably 0.01-0.10 kg phosphoric acid/min/kg alumina source, preferably 0.03-0.07 kg phosphoric acid/min/kg alumina source.

Preferably, the temperature of the reaction in step (3) of the method for preparing the first binder of the present invention is 65-90°C.

In the present invention, the introduction of the first clay into the first binder not only improves the mass transfer and heat transfer between the materials in the preparation process, but also avoids the possibility of local instantaneous violent reaction of the materials due to uneven exothermic overheating. The binder is solidified, so that the pH value of the binder can be adjusted more flexibly to obtain a binder with a high solid content, and the preparation does not require high-temperature depolymerization, concentration and other steps, and the preparation method is simple.

The bonding performance of the first bonding agent prepared by the method for preparing the first bonding agent provided by the present invention is equivalent to that of the phosphorus-aluminum inorganic bonding agent prepared by the method without adding the first clay. In addition, in a preferred embodiment of the present invention, the first clay introduced is retort clay with a layered structure, which can improve the heavy oil conversion ability of the finally prepared additive, and the additive has better selectivity.

According to the present invention, the boron-modified phosphorus- and metal-containing β molecular sieve can be further preferably based on the total weight of the boron-modified phosphorus- and metal-containing β molecular sieve, and the boron content is calculated as B ₂ O ₃ The boron content is 2-8% by weight calculated as B ₂ O ₃ . The β molecular sieve containing phosphorus and metal can be further preferably, in the β molecular sieve containing phosphorus and metal, based on the total weight of the β molecular sieve containing phosphorus and metal, the phosphorus content is calculated as P ₂ O ₅ 3-9% by weight, the metal content is 0.5-5% by weight in terms of metal oxides, and in the ²⁷ Al MAS NMR spectrum of the phosphorus and metal-containing β molecular sieve, the chemical shift is 40 ± 3ppm of the resonance signal The ratio of the peak area to the peak area of the resonance signal having a chemical shift of 54±3 ppm is 2 or more.

In the phosphorus and metal-containing β molecular sieve, the phosphorus is fully coordinated with the skeleton aluminum, the skeleton aluminum is fully protected, and has excellent hydrothermal stability and better product selectivity. In the ²⁷ Al MASNMR spectrogram of the phosphorus- and metal-containing β molecular sieve of the present invention, the resonance signal with a chemical shift of 54 ± 3ppm characterizes the four-coordinated framework aluminum species, and the resonance signal with a chemical shift of 40 ± 3ppm characterizes the chemical shift with phosphorus Coordinated framework aluminum species. More preferably, in the ²⁷ Al MASNMR spectrogram of the phosphorus- and metal-containing β molecular sieve provided by the present invention, the ratio of the peak area of the resonance signal with a chemical shift of 40±3ppm to the peak area of the resonance signal with a chemical shift of 54±3ppm For 2-5:1.

According to the present invention, the metal in the phosphorus- and metal-containing β molecular sieve can help improve the selectivity of low-carbon olefins in the product during catalytic cracking. Preferably, the metal may be at least one selected from Fe, Co, Ni, Cu, Mn, Zn and Sn.

In the present invention, preferably, the method for preparing phosphorus- and metal-containing β molecular sieves may include: passing the raw powder of β molecular sieves through at least two non-overlapping steps from low to high within the temperature range of 200°C to 800°C After the temperature interval treatment to remove the template agent, the step of phosphorus and metal modification is carried out.

More specifically, the method for preparing phosphorus- and metal-containing β molecular sieves may include: (i) performing ammonium exchange on sodium-type β molecular sieves to obtain molecular sieves with a Na ₂ O content of less than 0.2% by weight; (ii) converting step (i) into After the molecular sieve is dried, treat it at a temperature range of 200-400°C for at least 0.5 hours, and then heat it up to a temperature range of 500-800°C within at most 2 hours and treat it for at least 0.5 hours to remove the template agent; (iii) introduce phosphorus-containing Compounds and metal compounds modify the molecular sieve obtained in step (ii); (iv) calcining the molecular sieve obtained in step (iii) at 400-800° C. for at least 0.5 hours.

The method for preparing phosphorus- and metal-containing β molecular sieves provided by the present invention is compared with the modification method of existing β molecular sieves, and the main difference is that the preparation method of the present invention is to prepare β molecular sieve former powder (sodium type containing organic template) β molecular sieves) are treated in a non-overlapping temperature range from low to high to calcine to remove the template agent, and then modify phosphorus and metal.

In step (i) of the method for preparing phosphorus- and metal-containing β molecular sieves provided by the present invention, the sodium-type β-molecular sieve (Naβ-molecular sieve) can be a sodium-type β-molecular sieve obtained by conventional crystallization (such as USP3,308,069, CN1324762A) . Usually, the sodium content in the sodium-type β molecular sieve is 4-6% by weight calculated as sodium oxide. The ammonium exchange is a process of reducing the sodium content. Preferably, the ammonium exchange in step (i) is based on the sodium type β molecular sieve: ammonium salt: H ₂ O = 1: (0.1-1): (5-10 ) weight ratio, at room temperature to 100 ℃, carry out the process of exchanging at least 0.5 hours, preferably 0.5-2 hours and filtering, this process is carried out at least once, preferably the ammonium exchange process can be repeated 1-4 times, so that the β molecular sieve The Na ₂ O content is less than 0.2% by weight. The ammonium salt may be a commonly used inorganic ammonium salt, and may be selected from at least one of ammonium chloride, ammonium sulfate or ammonium nitrate.

The step (ii) of the method for preparing phosphorus- and metal-containing β molecular sieves provided by the present invention is a process of treating the molecular sieve obtained in the step (i) in different temperature ranges from low temperature to high temperature to remove templates. The treatment is calcination in at least two non-overlapping temperature ranges from low to high within the range of 200°C to 800°C. The low temperature range is 200-400°C, preferably 300-350°C; the high temperature range is 500-800°C, preferably 500-600°C. For example, the treatment is to roast the β molecular sieve with the Na ₂ O content less than 0.2% by weight after the ammonium exchange in step (i) after drying at 200-400°C, preferably 300-350°C for at least 0.5 hours, preferably 1- 12 hours, and then heating up to 500-800° C. for at least 0.5 hours, preferably 1-8 hours, within a maximum of 2 hours, preferably within 1 hour.

In the present invention, in the method for preparing phosphorus- and metal-containing β molecular sieves, the molecular sieve obtained in step (i) may be dried at 120-180°C for at least 1 hour before step (ii).

In step (iii) of the method for preparing phosphorus- and metal-containing β molecular sieves provided by the present invention, the phosphorus-containing compound may be selected from at least one of phosphoric acid, ammonium hydrogen phosphate, ammonium dihydrogen phosphate and ammonium phosphate. The metal compound may be selected from water-soluble salts of metals, and the water-soluble salts of metals may be selected from one of sulfates, nitrates or chlorides. The metal may be selected from at least one of Fe, Co, Ni, Cu, Mn, Zn and Sn. The water-soluble salt of the metal is exemplified but not limited to iron sulfate, cobalt sulfate, nickel sulfate, copper sulfate, manganese sulfate, zinc sulfate, tin sulfate, iron nitrate, cobalt nitrate, nickel nitrate, copper nitrate, manganese nitrate, zinc nitrate, Tin nitrate, ferric chloride, cobalt chloride, nickel chloride, copper chloride, manganese chloride, zinc chloride, tin chloride, etc.

The modification described in step (iii) of the method for preparing phosphorus- and metal-containing β molecular sieves provided by the present invention can be carried out by means of impregnation or ion exchange. Wherein said impregnation can be carried out in one of the following three ways:

(a) The beta molecular sieve obtained in step (ii) after removing the template agent and the aqueous solution of the calculated amount of phosphorus-containing compound are beaten and dried evenly at room temperature to 95° C., and then roasted at 400-800° C., and then compared with the calculated A large amount of aqueous solutions containing at least one metal compound of Fe, Co, Ni, Cu, Mn, Zn and Sn are mixed uniformly at room temperature to 95 ° C, and dried;

(b) The β molecular sieve obtained in step (ii) after removing the template and the calculated amount of the aqueous solution of the phosphorus-containing compound are beaten and dried evenly at room temperature to 95 ° C, and then mixed with the calculated amount of the β molecular sieve containing Fe, Co, Ni, Cu 1. The aqueous solution of at least one metal compound among Mn, Zn and Sn is mixed uniformly and dried at room temperature to 95°C, wherein the order of impregnating the above two aqueous solutions can also be reversed;

(c) a mixed aqueous solution of the β molecular sieve obtained in step (ii) after removing the template and a calculated amount of a phosphorus-containing compound and a compound of at least one metal in Fe, Co, Ni, Cu, Mn, Zn and Sn Mix well at room temperature to 95°C and dry.

In the step (iii) of the method for preparing phosphorus- and metal-containing β molecular sieves provided by the present invention, the modification also includes ion exchange, which can be specifically: the β molecular sieve obtained in step (ii) after removing the template agent and The calculated amount of phosphorus-containing compound aqueous solution is beaten and dried at room temperature to 95 °C, and then roasted at 400-800 °C, and then mixed with the calculated amount of Fe, Co, Ni, Cu, Mn, Zn and Sn at least An aqueous solution of a metal compound is uniformly mixed at a solid-to-liquid ratio of 1:(5-20), then stirred at 80-95°C for 2-3 hours and filtered to complete ion exchange. This exchange can be repeated many times, and the sample obtained after the exchange is washed with water for many times and then dried.

In the method for preparing phosphorus- and metal-containing β molecular sieves provided by the present invention, step (iv) is to roast the molecular sieve obtained in step (iii) at 400-800°C, preferably 500-600°C, for at least 0.5 hours, preferably 0.5-8 Hour. Wherein the calcination treatment can be performed by dry calcination or wet calcination, and the wet calcination is preferably carried out under 1-100%, more preferably 100% water vapor atmosphere.

According to the present invention, boron can be introduced into the phosphorus- and metal-containing β molecular sieve obtained by the above preparation method to obtain the boron-modified phosphorus- and metal-containing β molecular sieve. In the method for introducing boron, preferably, the β molecular sieve containing phosphorus and metal is impregnated with equal volumes of a solution containing a boron-containing compound to prepare the boron-modified β molecular sieve containing phosphorus and metal. The equal-volume impregnation can adopt the conditions commonly used in the art, and then dry and roast the phosphorus- and metal-containing β molecular sieve impregnated with the boron-containing compound, and convert the boron-containing compound into boron species to exist in the pores of the β molecular sieve or The surface of the β molecular sieve. The addition amount of the boron-containing compound is such that in the obtained boron-modified phosphorus- and metal-containing β molecular sieve, the boron content is based on the total weight of the boron _- modified phosphorus- and metal-containing β molecular sieve as B2 O ₃ is 0.5-10% by weight, preferably, the boron content is 2-8% by weight as B ₂ O ₃ .

According to the present invention, preferably, the boron-containing compound can be selected from at least one of boric acid, metaboric acid, ammonium pentaborate and ammonium tetraborate; preferably, the boron-containing compound is boric acid. The solution containing the boron-containing compound may be an aqueous solution of the boron-containing compound, and the mass concentration of the solution may be 1-35% by weight, for example, 5-30% by weight.

According to the present invention, preferably, the method also includes introducing an optional phosphorus additive after the calcination, and preferably, the amount of the phosphorus additive added is such that, in the obtained auxiliary agent, the total dry basis of the auxiliary agent is Based on weight, the content of the phosphorus additive is not more than 15% by weight calculated as P ₂ O ₅ . Wherein, in the obtained auxiliary agent, the content of the phosphorus additive is calculated according to the feeding amount of the phosphorus additive.

In the present invention, the mode of introducing the phosphorus additive can be at least one of the following methods, but is not limited to these methods:

A) adding phosphorus additives to the slurry before the drying and forming;

B) After the calcination, the phosphorus additive is impregnated or chemically adsorbed, and then introduced by solid-liquid separation (if necessary), drying and calcination; wherein the drying temperature is from room temperature to 400°C, preferably 100-300°C, and the calcination The temperature is 400-700°C, preferably 450-650°C, and the firing time is 0.5-100 hours, preferably 0.5-10 hours.

In the present invention, the phosphorus additive may be selected from phosphorus compounds. Described phosphorus compound can comprise the inorganic compound of phosphorus and/or organic compound, can be easily soluble in water, also can be the phosphorus compound of insoluble in water or insoluble in water, the embodiment of described phosphorus compound can be selected from phosphorus At least one of oxides, phosphoric acid, phosphate, phosphite, hypophosphite, alkali phosphate, acid phosphate and phosphorus-containing organic compounds. Preferably, the phosphorus compound may be at least one of phosphoric acid, ammonium phosphate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, aluminum phosphate and aluminum phosphate sol.

In the present invention, the second binder and the second clay may be as described above, and will not be repeated here.

The catalytic cracking aid provided by the invention is suitable for catalytic cracking of hydrocarbon oil. When used in the catalytic cracking process, it can be added to the catalytic cracking reactor alone or mixed with the cracking catalyst. Generally, based on the total amount of the catalytic cracking additive and the cracking catalyst, the content of the catalytic cracking additive provided by the present invention is 1-50% by weight, preferably 3-35% by weight.

The catalytic cracking aid provided by the present invention can be used for the processing of various hydrocarbon oils, and the hydrocarbon oils can be selected from various petroleum fractions, for example, can be selected from crude oil, atmospheric residue, vacuum residue, and atmospheric wax oil , vacuum gas oil, straight-run gas oil, at least one of propane light/heavy deoiling, coker gas oil and coal liquefaction products. The hydrocarbon oil may contain heavy metal impurities such as nickel and vanadium and impurities such as sulfur and nitrogen. For example, the content of sulfur can be as high as 3.0% by weight, the content of nitrogen can be as high as 2.0% by weight, and the content of metal impurities such as vanadium and nickel can be as high as 3000ppm.

The catalytic cracking aid provided by the invention is used in the catalytic cracking process, and the hydrocarbon oil cracking conditions can be conventional catalytic cracking conditions. Generally speaking, the cracking conditions of hydrocarbon oil include reaction temperature of 400-600°C, preferably 450-550°C, weight hourly space velocity of hydrocarbon oil of 10-120 hours ^-1 , preferably 10-80 hours ^-1 , solvent oil The ratio (weight ratio of catalyst (including cracking catalyst and catalytic cracking aid) to hydrocarbon oil) is 1-20:1, preferably 3-15:1.

The catalytic cracking additive provided by the invention can be used in various existing catalytic cracking reactors, for example, it can be used in fixed bed reactors, fluidized bed reactors, riser reactors, multi-reaction zone reactors and the like for catalytic cracking.

It should be noted that the compositions and contents of the catalytic cracking aid, the boron-modified phosphorus- and metal-containing β molecular sieve and the first binder provided by the present invention are all calculated according to the actual feeding amount.

The following examples will further illustrate the present invention, but do not limit the present invention thereby.

Some raw materials used are as follows:

Pseudo-boehmite: produced by Shandong Aluminum Company, with a solid content of 60% by weight;

Aluminum sol: produced by Sinopec Catalyst Qilu Branch, with an Al ₂ O ₃ content of 21.5% by weight;

Water glass: produced by Sinopec Catalyst Qilu Branch, the content of _SiO2 is 28.9 _% by weight, and the content of Na2O is 8.9%;

Kaolin is produced by Suzhou Kaolin Company, with a solid content of 78% by weight;

Rectorite: Hubei Zhongxiang Mingliu Rectorite Development Co., Ltd., quartz sand content < 3.5 wt%, Al ₂ O ₃ content 39.0 wt%, Fe ₂ O ₃ content 2.0 wt%, Na ₂ O content 0.03 wt% , the solid content is 77% by weight;

SB aluminum hydroxide powder: produced by Germany _Condex company, _Al2O3 content is 75% by weight;

γ-alumina powder: produced by Germany _Condex company, _Al2O3 content is 95% by weight;

Hydrochloric acid: chemically pure, with a concentration of 36-38% by weight, produced by Beijing Chemical Factory.

Examples 1-10 prepared phosphorus- and metal-containing β molecular sieves used in the present invention; Comparative Examples 1-2 prepared comparative molecular sieves. ²⁷ Al MAS NMR peak area ratio is shown in Table 1.

In the β molecular sieve samples of each example and comparative example, Na ₂ O, Fe ₂ O ₃ , Co ₂ O ₃ , NiO, CuO, Mn ₂ O ₃ , ZnO, SnO ₂ , Al ₂ O ₃ , SiO ₂ , P ₂ The content of O ₅ and B ₂ O ₃ is measured by X-ray fluorescence method (see "Petrochemical Analysis Method (RIPP Experimental Method)", edited by Yang Cuiding et al., Science Press, published in 1990), ²⁷ Al MAS NMR adopts Bruker Avance III 500MHz The nuclear magnetic resonance instrument is used for testing, and the peak area of each peak is calculated by the integration method after the resonance peak spectrum is divided into peaks and fitted.

Example 1

This example is used to illustrate the preparation method of the phosphorous and metal-containing β molecular sieve of the present invention.

(1) Exchange and wash zeolite beta (Naβ, produced by Qilu Catalyst Factory, SiO ₂ /Al ₂ O ₃ =25, sodium oxide content of 4.5% by weight, the same below) with NH ₄ Cl solution until the Na ₂ O content is lower than 0.2 % by weight, filtered to obtain filter cake;

(2) Dry the filter cake obtained in (1), roast the obtained sample at 350°C for 2 hours, then heat up to 550°C for 40 minutes and roast for 4 hours to remove the templating agent to obtain molecular sieves;

(3) Take 100g (dry basis) of the molecular sieve obtained in (2) and add water to prepare a molecular sieve slurry with a solid content of 40% by weight, and mix it with 6.8g of H ₃ PO ₄ (concentration 85% by weight) and 3.2g of Cu ( The solution prepared by dissolving NO ₃ ) ₂ 3H ₂ O in 30g water was mixed, soaked and dried to obtain the sample;

(4) The sample obtained in (3) was calcined at 550° C. for 2 hours to obtain the phosphorus- and metal-containing β molecular sieve A1 provided by the present invention.

The chemical composition of A1: 0.1Na ₂ O·6.6Al ₂ O ₃ ·3.8P ₂ O ₅ ·1.0CuO·88.6SiO ₂ ; ²⁷ Al MAS NMR peak area ratios are listed in Table 1.

Example 2

This example is used to illustrate the preparation method of the phosphorous and metal-containing β molecular sieve of the present invention.

(1) Exchanging and washing the zeolite beta with NH ₄ Cl solution until the Na ₂ O content is lower than 0.2% by weight, and filtering to obtain a filter cake;

(2) Dry the filter cake obtained in (1), roast the obtained sample at 150°C for 2 hours, then heat up to 350°C for 2 hours in 30 minutes, then heat up to 500°C for 4 hours in 30 minutes to remove the templating agent , get molecular sieve;

(3) Take 100g (dry basis) of the molecular sieve obtained in (2) and add water to prepare a molecular sieve slurry with a solid content of 40% by weight, and mix it with 11.8g of H ₃ PO ₄ (concentration 85% by weight) and 6.3g of CuCl ₂ The solution prepared by dissolving in 90g of water was mixed, dipped and dried to obtain the sample;

(4) Calcining the sample obtained in (3) at 550° C. for 2 hours to obtain the phosphorus and metal-containing β molecular sieve A2 provided by the present invention.

The chemical composition of A2: 0.1Na ₂ O·6.0Al ₂ O ₃ ·6.7P ₂ O ₅ · ^3.4CuO ·83.7SiO ₂ ;

Example 3

This example is used to illustrate the preparation method of the phosphorous and metal-containing β molecular sieve of the present invention.

(1) Exchanging and washing the zeolite beta with NH ₄ Cl solution until the Na ₂ O content is lower than 0.2% by weight, and filtering to obtain a filter cake;

(2) drying the filter cake obtained in (1), roasting the obtained sample at 350°C for 2 hours, then heating up to 600°C for 50 minutes and roasting for 4 hours to remove the template agent to obtain molecular sieves;

(3) Take 100 g (dry basis) of the molecular sieve obtained in (2) and add water to prepare a molecular sieve slurry with a solid content of 40% by weight, and mix and impregnate with a solution prepared by dissolving 4.2 g of NH ₄ H ₂ PO ₄ in 60 g of water , dried, and roasted at 550°C for 2 hours, and then exchanged with Cu(NO ₃ ) ₂ solution with a concentration of 5% by weight at a ratio of 5:1 to solid-liquid ratio for 2 hours at 80-90°C, filtered, and then Exchange several times until the target amount is reached to obtain samples;

(4) Calcining the sample obtained in (3) at 550° C. for 2 hours to obtain the phosphorus and metal-containing β molecular sieve A3 provided by the present invention.

The chemical composition of A3: 0.03Na ₂ O·6.4Al ₂ O ₃ ·3.4P ₂ O ₅ ·2.0CuO·88.2SiO ₂ ; ²⁷ Al MAS NMR peak area ratio is listed in Table 1.

Example 4

This example is used to illustrate the preparation method of the phosphorous and metal-containing β molecular sieve of the present invention.

(1) Exchanging and washing the zeolite beta with NH ₄ Cl solution until the Na ₂ O content is lower than 0.2% by weight, and filtering to obtain a filter cake;

(2) drying the filter cake obtained in (1), roasting the obtained sample at 300°C for 2 hours, then raising the temperature to 550°C for 60 minutes and roasting for 4 hours to remove the template agent to obtain molecular sieves;

(3) Add water to the molecular sieve 100g (dry basis) obtained in (2) to prepare a molecular sieve slurry with a solid content of 40% by weight, and mix it with 6.9g of H ₃ PO ₄ (concentration 85% by weight) and 8.1g of Fe ( The solution prepared by dissolving NO ₃ ) ₃ 9H ₂ O in 90g of water was mixed, dipped and dried to obtain a sample;

(4) Calcining the sample obtained in (3) at 550° C. for 2 hours to obtain the phosphorus- and metal-containing β molecular sieve A4 provided by the present invention.

The chemical composition of A4: 0.1Na ₂ O·6.4Al ₂ O ₃ ·3.9P ₂ O ₅ ·1.4Fe ₂ O ₃ ·88.1SiO ₂ ; ²⁷ Al MAS NMR peak area ratios are listed in Table 1.

Example 5

This example is used to illustrate the preparation method of the phosphorous and metal-containing β molecular sieve of the present invention.

(1) Exchanging and washing the zeolite beta with NH ₄ Cl solution until the Na ₂ O content is lower than 0.2% by weight, and filtering to obtain a filter cake;

(2) Dry the filter cake obtained in (1), roast the obtained sample at 350°C for 2 hours, then heat up to 550°C for 40 minutes and roast for 4 hours to remove the templating agent to obtain molecular sieves;

(3) Add water to 100 g (dry basis) of the molecular sieve obtained in (2) to prepare a molecular sieve slurry with a solid content of 40% by weight, and mix it with 9.3g of H ₃ PO ₄ (concentration 85% by weight) and 33.6g of Co ( NO ₃ ) · 6H ₂ O was dissolved in 90g of water to prepare the solution, mixed, soaked and dried to obtain the sample;

(4) Calcining the sample obtained in (3) at 550° C. for 2 hours under a 100% water vapor atmosphere to obtain the phosphorus and metal-containing β molecular sieve A5 provided by the present invention.

The chemical composition of A5: 0.1Na ₂ O·5.8Al ₂ O ₃ ·5.2P ₂ O ₅ ·9.3Co ₂ O ₃ · ^79.6SiO ₂ ;

Example 6

This example is used to illustrate the preparation method of the phosphorous and metal-containing β molecular sieve of the present invention.

(1) Exchanging and washing the zeolite beta with NH ₄ Cl solution until the Na ₂ O content is lower than 0.2% by weight, and filtering to obtain a filter cake;

(2) Dry the filter cake obtained in (1), roast the obtained sample at 350°C for 2 hours, then heat up to 550°C for 40 minutes and roast for 4 hours to remove the templating agent to obtain molecular sieves;

(3) Take 100g (dry basis) of the molecular sieve obtained in (2) and add water to prepare a molecular sieve slurry with a solid content of 40% by weight, and mix it with 6.0g of H ₃ PO ₄ (concentration 85% by weight) and 6.3g of Ni ( NO ₃ ) ₂ 6H ₂ O was dissolved in 90g of water to prepare the solution, mixed, soaked and dried to obtain the sample;

(4) Calcining the sample obtained in (3) at 550° C. for 2 hours to obtain the phosphorus- and metal-containing β molecular sieve A6 provided by the present invention.

The chemical composition of A6: 0.08Na ₂ O·6.4Al ₂ O ₃ ·4.1P ₂ O ₅ ·1.7NiO·87.7SiO ₂ ; ²⁷ Al MAS NMR peak area ratio is listed in Table 1.

Example 7

This example is used to illustrate the preparation method of the phosphorous and metal-containing β molecular sieve of the present invention.

(1) Exchanging and washing the zeolite beta with NH ₄ Cl solution until the Na ₂ O content is lower than 0.2% by weight, and filtering to obtain a filter cake;

(2) Dry the filter cake obtained in (1), roast the obtained sample at 350°C for 2 hours, then heat up to 550°C for 40 minutes and roast for 4 hours to remove the templating agent to obtain molecular sieves;

(3) Take 100g (dry basis) of the molecular sieve obtained in (2) and add water to prepare a molecular sieve slurry with a solid content of 40% by weight, and mix it with 6.0g of H ₃ PO ₄ (concentration 85% by weight) and 35.4g of Mn ( NO ₃ ) ₂ was dissolved in 90g of water and the solution prepared was mixed, impregnated and dried to obtain the sample;

(4) The sample obtained in (3) was calcined at 550° C. for 2 hours to obtain the phosphorus- and metal-containing β molecular sieve A7 provided by the present invention.

The chemical composition of A7: 0.09Na ₂ O·6.1Al ₂ O ₃ ·3.6P ₂ O ₅ ·6.1Mn ₂ O ₃ · ^84.1SiO ₂ ;

Example 8

This example is used to illustrate the preparation method of the phosphorous and metal-containing β molecular sieve of the present invention.

(1) Exchanging and washing the zeolite beta with NH ₄ Cl solution until the Na ₂ O content is lower than 0.2% by weight, and filtering to obtain a filter cake;

(2) Dry the filter cake obtained in (1), roast the obtained sample at 350°C for 2 hours, then heat up to 550°C for 40 minutes and roast for 4 hours to remove the templating agent to obtain molecular sieves;

(3) Add water to 100 g (dry basis) of the molecular sieve obtained in (2) to prepare a molecular sieve slurry with a solid content of 40% by weight, and mix it with 4.8g of H ₃ PO ₄ (concentration 85% by weight) and 5.9g of Zn ( NO ₃ ) ₂ 6H ₂ O was dissolved in 90g of water to prepare the solution, mixed, soaked and dried to obtain the sample;

(4) The sample obtained in (3) was calcined at 550° C. for 2 hours to obtain the phosphorus- and metal-containing β molecular sieve A8 provided by the present invention.

The chemical composition of A8: 0.14Na ₂ O·6.5Al ₂ O ₃ ·3.1P ₂ O ₅ ·1.5ZnO·88.8SiO ₂ ; ²⁷ Al MAS NMR peak area ratio is listed in Table 1.

Example 9

This example is used to illustrate the preparation method of the phosphorous and metal-containing β molecular sieve of the present invention.

(1) Exchanging and washing the zeolite beta with NH ₄ Cl solution until the Na ₂ O content is lower than 0.2% by weight, and filtering to obtain a filter cake;

(2) Dry the filter cake obtained in (1), roast the obtained sample at 350°C for 2 hours, then heat up to 550°C for 40 minutes and roast for 4 hours to remove the templating agent to obtain molecular sieves;

(3) Add water to the molecular sieve 100g (dry basis) obtained in (2) to prepare a molecular sieve slurry with a solid content of 40% by weight, and mix it with 15g of H ₃ PO ₄ (concentration 85% by weight) and 3.7g of SnCl ₄ . The solution prepared by dissolving 5H ₂ O in 90g of water was mixed, impregnated and dried to obtain the sample;

(4) The sample obtained in (3) was calcined at 550° C. for 2 hours to obtain the phosphorus- and metal-containing β molecular sieve A9 provided by the present invention.

The chemical composition of A9: 0.10Na ₂ O·6.0Al ₂ O ₃ ·9.1P ₂ O ₅ ·1.6SnO ₂ ·83.2SiO ₂ ; ²⁷ Al MAS NMR peak area ratios are listed in Table 1.

Example 10

This example is used to illustrate the preparation method of the phosphorous and metal-containing β molecular sieve of the present invention.

(1) Exchange and wash the β molecular sieve with NH ₄ Cl solution until the Na ₂ O content is lower than 0.2% by weight, and filter to obtain a filter cake;

(2) Dry the filter cake obtained in (1), roast the obtained sample at 350°C for 2 hours, then heat up to 550°C for 40 minutes and roast for 4 hours to remove the templating agent to obtain molecular sieves;

(3) Add 100 g (dry basis) of the molecular sieve obtained in (2) to 15 g of H ₃ PO ₄ (concentration 85% by weight) and 3.2 g of Cu(NO ₃ ) ₂ ·3H ₂ O, 2.6 g of Zn (NO ₃ ) ₂ 6H ₂ O dissolved in 90g of water prepared by mixing, soaking and drying the sample;

(4) Calcining the sample obtained in (3) at 550° C. for 2 hours to obtain the phosphorus and metal-containing β molecular sieve A10 provided by the present invention.

The chemical composition of A10: 0.10Na ₂ O·6.0Al ₂ O ₃ ·9.1P ₂ O ₅ ·1.0CuO· ^0.6ZnO ·83.2SiO ₂ ;

Comparative example 1

This comparative example illustrates the preparation of phosphorus and metal-containing β molecular sieves according to the method of CN1872685A.

100g (dry basis) Naβ zeolite (Naβ zeolite used in Example 1) is exchanged and washed with NH ₄ Cl solution until Na ₂ O content is lower than 0.2% by weight, and filters to obtain a filter cake; 85% by weight) and 8.1g of Fe(NO ₃ ) ₃ ·9H ₂ O dissolved in 90g of water were mixed, impregnated and dried; the obtained sample was calcined at 550°C for 2 hours to obtain comparative molecular sieve B1.

Chemical composition of B1: 0.1Na ₂ O·6.0Al ₂ O ₃ ·4.1P ₂ O ₅ ·1.5Fe ₂ O ₃ ·88.3SiO ₂ ; ²⁷ Al MAS NMR peak area ratios are listed in Table 1.

Comparative example 2

(1) Exchange and wash the β molecular sieve (produced by Qilu Catalyst Factory, SiO ₂ /Al ₂ O ₃ =25, sodium oxide content of 4.5% by weight) with NH ₄ Cl solution until the Na ₂ O content is lower than 0.2% by weight, and filter to obtain filter cake;

(2) drying the filter cake obtained in (1), and roasting the obtained sample at 550° C. for 4 hours to remove the templating agent to obtain molecular sieves;

(3) Take 100 g (dry basis) of the molecular sieve obtained in (2), and dissolve 6.9 g of H ₃ PO ₄ (concentration 85% by weight) and 8.1 g of Fe(NO ₃ ) ₃ 9H ₂ O in 90 g of water The prepared solution was mixed, impregnated, and dried to obtain a sample;

(4) The sample obtained in (3) was calcined at 550° C. for 2 hours to obtain comparative molecular sieve B2.

The chemical composition of B2: 0.1Na ₂ O·6.4Al ₂ O ₃ ·3.8P ₂ O ₅ ·1.5Fe ₂ O ₃ · ^88.1SiO ₂ ;

Table 1

Examples 11-19 Preparation of boron-modified phosphorus and metal-containing beta molecular sieves used in the present invention.

Example 11

Get 3kg (dry basis) of the A1 molecular sieve prepared in Example 1, impregnate with boric acid solution according to the equal-volume impregnation method, dry at 120°C, and roast at 450°C for 1 hour to obtain the β molecular sieve containing phosphorus and metal modified by boron, record Make A1-B. The boron content is shown in Table 2.

Examples 12-19

According to the method of Example 11, the difference is that the A2-A9 molecular sieves prepared in Examples 2-9 are used instead of A1 to prepare boron-modified phosphorous and metal-containing β molecular sieves A2-B to A9-B, wherein the boron content See Table 2.

Comparative example 3

According to the method of Example 11, the difference is that the molecular sieve B2 prepared in Comparative Example 2 was used instead of A1 to prepare a boron-modified phosphorus- and metal-containing β molecular sieve, which is denoted as B2-B, and the boron content is shown in Table 2.

Table 2

example serial number Boron content (calculated as B ₂ O ₃ ), wt% Example 11 A1-B 2.1 Example 12 A2-B 2.8 Example 13 A3-B 1.6 Example 14 A4-B 3.2 Example 15 A5-B 4.5 Example 16 A6-B 5.1 Example 17 A7-B 6.3 Example 18 A8-B 7.6 Example 19 A9-B 8.4 Comparative example 3 B2-B 32

Examples 20-23 Prepare the first binder used in the present invention, and its formula and composition are shown in Table 3.

Example 20

This example is used to illustrate the preparation of the first binder of the present invention.

Beat 0.74kg of pseudo-boehmite (0.45kg containing Al ₂ O ₃ ), 0.39kg of rectorite (0.30kg on a dry basis) and 1.6kg of decationized water for 30 minutes, and pour into the slurry under stirring Add 2.03 kg of concentrated phosphoric acid (mass concentration: 85% by weight), wherein the phosphoric acid addition rate is 0.04 kg phosphoric acid/min/kg pseudo-boehmite. After the concentrated phosphoric acid was added, the slurry was heated to 70° C., and then reacted at this temperature for 45 minutes to obtain the first binder N1. The material ratio is shown in Table 3.

Examples 21-23

The first binders N2-N4 were prepared according to the method of Example 20. The material ratio is shown in Table 3.

Comparative example 4

This comparative example prepares the phosphoraluminum glue (phosphoraluminum sol) used in the comparative example of the present invention.

The pseudo-boehmite (0.44kg on a dry basis) of 0.66kg and the decationized water of 1.75kg were beaten for 30 minutes, and the concentrated phosphoric acid (chemically pure, containing 85% by weight of phosphoric acid) of 2.6kg was added to the slurry under stirring, and the temperature was raised. to 70° C., and react at this temperature for 45 minutes to obtain phosphoraluminum glue (phosphorusaluminum inorganic binder) PAl-1. The material ratio is shown in Table 3.

table 3

Examples 24-32 Prepare the catalytic cracking aid provided by the present invention. The specific formula is shown in Table 4, and the preparation process is described as follows:

Example 24

Take molecular sieve A1-B, kaolin and pseudo-boehmite, add decationized water and alumina sol and beat for 120 minutes to obtain a slurry with a solid content of 30% by weight, add hydrochloric acid to adjust the pH of the slurry to 3, and continue beating for 45 minutes. Add the first binder N4, after stirring for 30 minutes, the product obtained is spray-dried under the conditions of the drying gas inlet temperature of 500°C and the tail gas temperature of 180°C to obtain microspheres with an average particle diameter of 67 microns. Calcined at 500°C for 1 hour to obtain the catalytic cracking ZJ1 provided by the present invention, the specific additive formulation is shown in Table 4.

Example 25

Take molecular sieve A2-B, kaolin and pseudo-boehmite, add decationized water and aluminum sol and beat for 120 minutes to obtain a slurry with a solid content of 30% by weight, add hydrochloric acid to adjust the pH value of the slurry to 3, and continue beating for 45 minutes. After adding the first binder N1 and stirring for 30 minutes, the obtained product was spray-dried under the conditions of a drying gas inlet temperature of 500°C and an exhaust gas temperature of 180°C to obtain microspheres with an average particle diameter of 65 microns. The microspheres were fired at 500°C for 1 hour.

Take the obtained microsphere product, add diammonium hydrogen phosphate aqueous solution, heat up to 60°C under stirring, react at this temperature for 20 minutes, vacuum filter and dry the slurry, and then roast at 500°C for 2 hours to obtain the present invention. The catalytic cracking additive ZJ2. The specific additive formulations are shown in Table 4.

Example 26

Take molecular sieve A3-B, pseudoboehmite, kaolin and diatomaceous earth, add deionized water and water glass and beat for 120 minutes to obtain a slurry with a solid content of 35% by weight, add hydrochloric acid to make the pH of the slurry = 3, and then beat for 45 minute. Add the first binder N1, stir for 30 minutes, and spray-dry the obtained product under the conditions of a dry gas inlet temperature of 500°C and an exhaust gas temperature of 180°C to obtain microspheres with an average particle diameter of 69 microns. Calcined at 500°C for 1 hour, the catalytic cracking additive ZJ3 provided by the present invention was obtained, and the specific additive formula is shown in Table 4.

Example 27

Take molecular sieve A4-B, pseudoboehmite and kaolin, add decationized water and aluminum sol and beat for 120 minutes to obtain a slurry with a solid content of 38% by weight, add hydrochloric acid to make the pH of the slurry = 3, and then beat for 45 minutes. Add the first binder N2 and stir for 30 minutes. The obtained product is spray-dried under the conditions of a dry air inlet temperature of 500°C and an exhaust gas temperature of 180°C to obtain microspheres with an average particle diameter of 65 microns, and the microspheres are calcined at 500°C for 1 hour to obtain the Catalytic cracking additive ZJ4, the specific additive formula is shown in Table 4.

Example 28

Take molecular sieve A5-B, pseudo-boehmite and kaolin, add decationized water and beat for 120 minutes to obtain a slurry with a solid content of 30% by weight, add hydrochloric acid to adjust the pH of the slurry to 3, and then beat for 45 minutes. Add the first binder N1 and stir for 30 minutes. The obtained product was spray-dried under the conditions of a dry air inlet temperature of 500° C. and an exhaust gas temperature of 180° C. to obtain microspheres with an average particle diameter of 65 microns. The microspheres were calcined at 500° C. for 1 hour to obtain the catalytic cracking additive ZJ5 provided by the present invention. The specific additive formula is shown in Table 4.

Example 29

Take molecular sieve A6-B and kaolin, add decationized water and aluminum sol and beat for 120 minutes to obtain a slurry with a solid content of 30% by weight, add hydrochloric acid to adjust the pH of the slurry to 3, and continue beating for 45 minutes. After adding the first binder N2 and the diammonium hydrogen phosphate solid and stirring evenly, the obtained product is spray-dried under the conditions of a dry air inlet temperature of 500°C and an exhaust gas temperature of 180°C to obtain micronized particles with an average particle diameter of 67 microns. balls, the microspheres were calcined at 400°C for 1 hour to obtain the catalytic cracking aid ZJ6 provided by the present invention. Specific additive formula table 4.

Example 30

Take molecular sieve A7-B, pseudo-boehmite and kaolin, add decationized water and aluminum sol and beat for 120 minutes to obtain a slurry with a solid content of 30% by weight, adjust the pH of the slurry to 3 with hydrochloric acid, and then continue beating for 45 minutes. Add the first binder N3, stir for 30 minutes, spray dry the obtained product under the condition of dry air inlet temperature of 500°C and tail gas temperature of 180°C to obtain microspheres with an average particle diameter of 68 microns, and place the microspheres in Calcined at 500°C for 1 hour to obtain the catalytic cracking aid ZJ7 provided by the present invention. The specific additive formulations are shown in Table 4.

Example 31

Take molecular sieve A8-B, kaolin clay and pseudo-boehmite, add decationized water and aluminum sol and beat for 120 minutes to obtain a slurry with a solid content of 30% by weight, add hydrochloric acid to make the pH of the slurry=3, continue beating for 30 minutes, add The first binder N3 was beaten for another 30 minutes, and then the product obtained was spray-dried under the conditions of a dry air inlet temperature of 500°C and an exhaust gas temperature of 180°C to obtain microspheres with an average particle diameter of 70 microns. Calcined at 500°C for 1 hour to prepare the catalytic cracking aid ZJ8 provided by the present invention. The specific additive formulations are shown in Table 4.

Example 32

Take molecular sieve A9-B, kaolin and water glass, add decationized water and beat for 120 minutes to obtain a slurry with a solid content of 30% by weight, add hydrochloric acid to make the pH of the slurry = 3, and continue beating for 30 minutes. Add the first binder N4, beat for another 30 minutes, then spray dry the obtained product under the conditions of dry air inlet temperature of 500°C and tail gas temperature of 180°C to obtain microspheres with an average particle diameter of 66 microns. The spheres were calcined at 500° C. for 1 hour to obtain the catalytic cracking aid ZJ9 provided by the present invention. The specific additive formulations are shown in Table 4.

Comparative example 5

Take molecular sieve A4-B, kaolin and pseudo-boehmite, add decationized water and aluminum sol and beat for 120 minutes to obtain a slurry with a solid content of 30% by weight, and add hydrochloric acid with a concentration of 36% by weight under stirring to make the pH of the slurry= 3.0, and then beating for 45 minutes, the product obtained was spray-dried under the condition of 500° C. of dry air inlet temperature and 180° C. of tail gas temperature to obtain microspheres with an average particle diameter of 65 microns. The microspheres were calcined at 500° C. for 1 Hours, the reference additive DB1 was prepared. Refer to Table 5 for the ratio of reference additives.

Comparative example 6

Take molecular sieve A4-B, kaolin and pseudo-boehmite, add decationized water and alumina sol and beat for 120 minutes to obtain a slurry with a solid content of 30% by weight, add hydrochloric acid under stirring, and control the pH of the slurry to 3.0 by the amount of hydrochloric acid. After the mixture continued to be beaten for 45 minutes, the phosphoraluminum glue PAl-1 prepared in Comparative Example 3 was added, and stirred for another 30 minutes, and the obtained product was spray-dried at an inlet temperature of 500°C and an exhaust gas temperature of 180°C to obtain an average particle Microspheres with a diameter of 65 microns. The microspheres were calcined at 500°C for 1 hour to prepare the reference additive DB2. Refer to Table 5 for the ratio of reference additives.

Comparative example 7-8

Auxiliaries were prepared according to the method of Example 27, except that molecular sieves B1 and B2 were used to replace A4-B respectively to prepare reference auxiliaries DB3 and DB4. Refer to Table 5 for the ratio of reference additives.

Comparative example 9

The auxiliary agent was prepared according to the method of Comparative Example 5, except that molecular sieve B2-B was used instead of A4-B to obtain reference auxiliary agent DB5. Refer to Table 5 for the ratio of reference additives.

Comparative example 1

The auxiliary agent was prepared according to the method of Example 27, except that molecular sieve A4 was used instead of A4-B to prepare comparative agent BJ1. Refer to Table 5 for the ratio of reference additives.

Example 33

Get the auxiliary agents ZJ1 to ZJ9 that embodiment 24-32 provides to carry out strength index (being wear index) measurement, wherein measuring method is according to RIPP strength test standard method (measured with a straight tube strength meter, referring to "Petrochemical Analysis Method (RIPP Experimental Method) )", edited by Yang Cuiding, etc., Science Press, published in 1990), the intensity index A.I. was measured respectively, and the results are listed in Table 6.

Comparative example 10

The additives DB1 to DB5 provided in Comparative Examples 4-8 were used to measure the strength index (i.e. wear index), wherein the measurement method was carried out according to the RIPP strength test standard method (measured with a straight tube strength meter), and the strength index A.I. was measured respectively, The results are listed in Table 6. The strength of the contrast additive DB1 provided in Comparative Example 5 cannot meet the requirements of the catalytic cracking process, so no performance evaluation is made.

Comparative example 2

The auxiliary agent BJ1 provided in Comparative Example 1 was taken to measure the strength index (i.e. wear index), wherein the measurement method was carried out according to the RIPP strength test standard method (measured with a straight tube strength meter), and the strength index A.I. was measured respectively, and the results are listed in the table 6.

Example 34

The following examples take a fixed fluidized bed reactor as an example to illustrate the catalytic cracking reaction effect of the catalytic cracking additive provided by the present invention. Table 7 shows the physicochemical parameters of the cracking catalysts used. Table 8 shows the physicochemical parameters of the hydrocarbon oil used in the cracking reaction.

30g of ZJ4 was aged at 800°C and 100% steam atmosphere for 12 hours. Get a certain amount of aged ZJ4 mixed with a certain amount of industrial FCC equilibrium catalyst (industrial brand is the FCC equilibrium catalyst of MLC-500, the main properties are shown in Table 7), and the obtained mixture is loaded into a small fixed fluidized bed reaction as a catalyst The catalytic cracking reaction is carried out in the reactor of the device. The feed oil shown in Table 7 was used for catalytic cracking (see Table 8 for the properties of the feed oil).

Table 9 shows the weight composition, reaction conditions and reaction results of the catalyst mixture composed of a certain amount of aged ZJ4 and MLC-500 balance agent.

Examples 35-38

According to the method of Example 25, the difference is that ZJ4 is replaced by ZJ1, ZJ6, ZJ7 and ZJ8 respectively, and the amount of the balancer composition of them and MLC-500 is changed. For the weight composition, reaction conditions and reaction results of the specific mixture, see Table 10.

Comparative example 11-15

The following comparative examples take a fixed fluidized bed reactor as an example to illustrate the use of reference additives.

The method in Example 33 was followed except that ZJ4 was replaced by 100% commercial FCC balanced catalyst (MLC-500), 10% DB2-DB5 and 90% commercial FCC balanced catalyst mixture.

Table 9 shows the weight composition of the catalyst mixture used, the reaction conditions and the reaction results.

Comparative example 3

The following comparative examples take a fixed fluidized bed reactor as an example to illustrate the use of comparative additives.

The procedure in Example 33 was followed except that a mixture of 10% BJ1 and 90% commercial FCC equilibrium catalyst was used instead of ZJ4.

Table 9 shows the weight composition of specific mixtures, reaction conditions and reaction results.

In above-mentioned embodiment, comparative example and comparative example, what contained in the catalytic cracking aid ZJ1 that provides, ZJ4, ZJ6-ZJ8 is the β molecular sieve (A1-B, A4-B, A6 that contains phosphorus and metal of boron modification. -B, A7-B, A8-B), wherein, ZJ6 also contains phosphorus additives; what contained in the comparison aid BJ1 is β molecular sieve (A4, without boron modification) containing phosphorus and metal; contrast aid DB1 and The catalytic cracking aid ZJ4 is compared with the first binder; the contrast aid DB2 is compared with the catalytic cracking aid ZJ4, which does not contain the first binder, but contains phosphorus additives; the contrast aid DB3 contains Phosphorous and metal-containing β molecular sieves (B1, without boron modification) obtained by existing preparation methods; contrast aid DB4 contains phosphorus and metal-containing β molecular sieves without boron modification, and the molecular sieve is desorbed in the preparation method The template removal agent is only treated once at high temperature (B2, without boron modification, the template removal agent is only treated at high temperature once); the contrast aid DB5 contains the phosphorus and metal-containing β molecular sieve in the contrast aid DB4 through boron Modified β molecular sieve (B2-B, only one high temperature treatment for template removal).

As can be seen from the results in Table 1, in the ²⁷ Al MAS NMR spectrogram of the molecular sieve obtained in Example 1-10, the chemical shift is the peak area of the resonance signal of 40 ± 3ppm and the peak area of the resonance signal of 54 ± 3ppm is the chemical shift. The peak area ratios are all between 1-4, and the phosphorus in the molecular sieve is fully coordinated with the skeleton aluminum. The introduction of boron in Examples 11-19 makes the skeleton aluminum fully protected, and the number of L acid centers is reduced. The additional use of metals also helps to increase the selectivity to light olefins. In the ²⁷ Al MAS NMR spectrogram of the phosphorus-containing and metal-containing β molecular sieve obtained in Comparative Example 1-2, the chemical shift is the peak area of the resonance signal of 40 ± 3 ppm and the peak area of the resonance signal of 54 ± 3 ppm is the chemical shift The ratios are all less than 1, which is different from the beta molecular sieves in the examples.

In addition, an appropriate amount of the first binder prepared in Examples 20-23 is also introduced into the catalytic cracking auxiliary agent provided by the present invention, and after making auxiliary agents with other components through Examples 24-32, the The evaluation method evaluates the cracking reaction effect, as can be seen from Table 9 and Table 10, the catalytic cracking additive provided by the present invention can improve the output of liquefied gas output and isobutene under the situation of reducing gasoline loss, and can improve the isobutene in liquefied gas concentration, while reducing coke production. Therefore, the catalytic cracking liquefied gas yield obtained by the catalytic cracking additive is higher, the yield of ethylene, propylene and isobutylene is higher, the concentration of propylene and isobutene in the catalytic cracking liquefied gas is higher, and the concentration of ethylene in the dry gas is higher. Higher heavy oil conversion capacity, better coke and dry gas selectivity, and surprisingly higher liquid recovery. However, contrast aids and comparison aids cannot provide better performance.

In Table 6, the catalytic cracking additives provided by the present invention have good wear resistance and can meet the requirements of catalytic cracking units. The comparative additive DB1 does not contain phosphorus-aluminum binder, and the strength of the additive is poor, so it is not suitable for use in catalytic cracking units. DB2 uses the phosphor-aluminum binder of the prior art, and its strength is also worse than that of the first binder containing clay provided by the present invention.

table 5

Table 6

Example Numbering Auxiliary A.I. Comparative Examples Numbering Auxiliary A.I. Embodiment 33ZJ11.3 comparative example 5DB16.8 Embodiment 33ZJ21.8 comparative example 6DB23.6 Embodiment 33ZJ32.9 comparative example 7DB31.2 Embodiment 33ZJ40.9 comparative example 8DB41.3 Embodiment 33ZJ52.5 comparative example 9DB51.3 Embodiment 33ZJ62.8 Comparative Example 2BJ11.4 Example 33ZJ71.3 Example 33ZJ80.9 Example 33ZJ91.1

Table 7

Table 8

Claims (21)

1. A catalytic cracking additive for increasing the concentration of low-carbon olefins, the additive comprising: boron-modified phosphorus and metal-containing β molecular sieves, the first binding agent, the second binding agent and the optional second clay , wherein, the first binder is a phosphorus-aluminum inorganic binder containing the first clay, and the second binder is an inorganic oxide binder other than the first binder; Based on the total weight of the additive on a dry basis, the content of the boron-modified phosphorus- and metal-containing β molecular sieve is 10-75% by weight, and the content of the first binder is based on the first binder The sum of the dry weight of the aluminum component, the phosphorus component and the first clay in the agent is 3-30% by weight, the content of the second binder is 3-30% by weight in terms of oxides, and the The content of the second clay is 0-60% by weight on a dry basis; Wherein, based on the total weight of the first binder on a dry basis, the first binder includes 15-40% by weight of aluminum components calculated as Al ₂ O ₃ , aluminum components calculated as P ₂ O ₅ 45-80% by weight of the phosphorus component and 1-40% by weight of the first clay based on dry weight, and wherein the weight ratio P/Al of P in the phosphorus component to Al in the aluminum component is 1- 6:1; In the boron-modified phosphorus- and metal-containing β molecular sieve, based on the total weight of the boron-modified phosphorus- and metal-containing β molecular sieve, the boron content is 0.5-10% by weight in terms _of B2O3 _; In the β molecular sieve containing phosphorus and metal, based _on the total weight of the β molecular sieve containing phosphorus and metal, the phosphorus content is 0.5-10% by weight as _P2O5 , and the metal content is 0.5-10% by weight as metal oxide. 0.5-10% by weight, and in the ²⁷ Al MAS NMR spectrum of the β molecular sieve containing phosphorus and metal, the peak area of the resonance signal with a chemical shift of 40 ± 3 ppm is the same as the peak of the resonance signal with a chemical shift of 54 ± 3 ppm The area ratio is 1 or more. 2. auxiliary agent according to claim 1, wherein, in the β molecular sieve containing phosphorus and metal of described boron modification, take the gross weight of the β molecular sieve containing phosphorus and metal of described boron modification as a basis, boron The content is _2-8 % by weight in terms of B2O3 _; in the β molecular sieve containing phosphorus and metal, the phosphorus content is _3-9 % by weight in terms of _P2O5 , and the metal content is 0.5-9% in terms of metal oxides. 5% by weight, and in the ²⁷ Al MAS NMR spectrum of the β molecular sieve containing phosphorus and metal, the chemical shift is the difference between the peak area of the resonance signal of 40 ± 3ppm and the peak area of the resonance signal of 54 ± 3ppm The ratio is 2 or more. 3. The auxiliary agent according to claim 1, wherein the content of the boron-modified phosphorus and metal-containing β molecular sieve is 20-60% by weight, and the content of the first binder is expressed as the first The sum of the dry weight of the aluminum component, the phosphorus component and the first clay in the binder is 8-25% by weight, and the content of the second binder is 5-25% by weight in terms of oxides, The content of the second clay is 10-45% by weight on a dry basis. 4. The additive according to any one of claims 1-3, wherein the metal is selected from at least one of Fe, Co, Ni, Cu, Mn, Zn and Sn. 5. The auxiliary agent according to any one of claims 1-3, wherein, based on the total weight of the auxiliary agent on a dry basis, the auxiliary agent also contains no more than ₁₅ % by weight of _P2O5 Phosphorus additive. 6. A method for preparing a catalyst for improving the concentration of low-carbon olefins, the method comprising: a boron-modified phosphorus-containing and metal-containing β molecular sieve, the first binding agent, the second binding agent, optional Phosphorus additive, optional second clay, water and acidic liquid are mixed, and the obtained slurry is dried and molded and calcined; wherein, the first binder is a phosphorus-aluminum inorganic binder containing the first clay, and the The second binder is an inorganic oxide binder other than the first binder; Wherein, based on the total weight of the first binder on a dry basis, the first binder includes 15-40% by weight of aluminum components calculated as Al ₂ O ₃ , aluminum components calculated as P ₂ O ₅ 45-80% by weight of the phosphorus component and 1-40% by weight of the first clay on a dry basis, and wherein the weight ratio P/Al of P in the phosphorus component to Al in the aluminum component is 1-6 : 1, the pH value is 1-3.5; the solid content of the first binder is 15-60% by weight; In the boron-modified phosphorus- and metal-containing β molecular sieve, based on the total weight of the boron-modified phosphorus- and metal-containing β molecular sieve, the boron content is 0.5-10% by weight in terms _of B2O3 _; In the β molecular sieve containing phosphorus and metal, based _on the total weight of the β molecular sieve containing phosphorus and metal, the phosphorus content is 0.5-10% by weight as _P2O5 , and the metal content is 0.5-10% by weight as metal oxide. 0.5-10% by weight, and in the ²⁷ Al MAS NMR spectrum of the β molecular sieve containing phosphorus and metal, the peak area of the resonance signal with a chemical shift of 40 ± 3 ppm is the same as the peak of the resonance signal with a chemical shift of 54 ± 3 ppm The area ratio is 1 or more. 7. The method of claim 6, wherein the boron-modified phosphorous and metal-containing beta molecular sieve, first binder, second binder and optional second clay are added in amounts such that In the catalytic cracking additive, based on the total weight of the additive on a dry basis, the content of the boron-modified phosphorus- and metal-containing β molecular sieve is 10-75% by weight, and the content of the first binder is The sum of the dry weight of the aluminum component, the phosphorus component and the first clay in the first binder is 3-30% by weight, and the content of the second binder is 3% by oxide. -30% by weight, the content of the second clay is 0-60% by weight on a dry basis. 8. The method according to claim 6, wherein the preparation method of the first binder comprises: (1) mixing the alumina source, the first clay and water to obtain a mixture; (2) contacting the mixture obtained in step (1) with concentrated phosphoric acid to obtain a slurry; (3) reacting the slurry obtained in step (2); Wherein, the weight ratio of the first clay in dry basis to the alumina source in Al ₂ O ₃ is 0.025-2.66:1; the usage amount of the concentrated phosphoric acid and alumina source makes the P in the concentrated phosphoric acid The weight ratio P/Al to Al in the alumina source is 1-6:1; the reaction temperature is 50-99°C, and the reaction time is 15-90min. 9. The method of claim 8, wherein the first binder comprises 15-35% by weight Al ₂ O ₃ derived from the alumina source, 50- 75% by weight of _P2O5 and 8-35% by weight of the first clay _on a dry basis, and wherein the weight ratio P/Al of P in the concentrated phosphoric acid to Al in the alumina source is 2-5:1. 10. The method according to claim 8 or 9, wherein the alumina source is ρ-alumina, χ-alumina, η-alumina, γ-alumina, κ-alumina, δ-alumina , at least one of θ-alumina, gibbsite, pyrenite, diaspore, diaspore, boehmite and pseudo-boehmite; the first clay is kaolin, sepiolite , at least one of attapulgite, retort earth, montmorillonite and diatomite. 11. The method according to claim 6, wherein the method for preparing phosphorus- and metal-containing β molecular sieves comprises: passing the raw powder of β molecular sieves through at least two steps from low to high in the temperature range of 200°C to 800°C. The step of phosphorous and metal modification is carried out after the template agent is removed by treatment in non-overlapping temperature intervals. 12. The method according to claim 11, wherein the method for preparing phosphorus and metal-containing β molecular sieves comprises: (i) Exchanging sodium-type β molecular sieves with ammonium to obtain molecular sieves with a Na2O content of less _than 0.2% by weight; (ii) After drying the molecular sieve obtained in step (i), treat it at a temperature range of 200-400°C for at least 0.5 hours, and then heat it up to a temperature range of 500-800°C within 2 hours for at least 0.5 hours to remove the template agent; (iii) introducing phosphorus-containing compounds and metal compounds to modify the molecular sieve obtained in step (ii); (iv) calcining the molecular sieve obtained in step (iii) at 400-800° C. for at least 0.5 hours. 13. The method according to claim 12, wherein the ammonium exchange in step (i) is based on sodium type β molecular sieve: ammonium salt: H ₂ O = 1: (0.1-1): (5-10) Weight ratio, exchange at room temperature to 100°C for at least 0.5 hours and filter, this process is performed at least once; the ammonium salt is at least one selected from ammonium chloride, ammonium sulfate and ammonium nitrate. 14. The method according to claim 12, wherein, before step (ii), the molecular sieve obtained in step (i) is dried at 120-180°C for at least 1 hour. 15. The method according to claim 12, wherein, the phosphorus-containing compound described in step (iii) is at least one selected from phosphoric acid, ammonium hydrogen phosphate, ammonium dihydrogen phosphate and ammonium phosphate; the metal compound is Water-soluble salts of metals. 16. The method according to claim 15, wherein the water-soluble salt of the metal is one selected from the group consisting of sulfate, nitrate or chloride of the metal. 17. The method of claim 16, wherein the metal is at least one selected from Fe, Co, Ni, Cu, Mn, Zn, and Sn. 18. The method according to claim 12, wherein the calcination treatment in step (iv) is calcination under a water vapor atmosphere. 19. The method according to any one of claims 11-18, wherein the β molecular sieve containing phosphorus and metal is impregnated with a solution containing a boron-containing compound to prepare the boron-modified phosphorus-containing and metal-containing β molecular sieve. Metal β molecular sieve, the boron-containing compound is selected from at least one of boric acid, metaboric acid, ammonium pentaborate and ammonium tetraborate. 20. The method of claim 6, further comprising introducing an optional phosphorus additive after said roasting. 21. according to the method described in claim 6 or 20, wherein, the add-on of described phosphorus additive makes in the catalytic cracking auxiliary agent obtained, take the dry base gross weight of this auxiliary agent as a basis, the content of described phosphorus additive is P ₂ O ₅ does not exceed 15% by weight.