CN107973303A - MFI structure molecular sieve a kind of phosphorous and containing carried metal and preparation method thereof - Google Patents

Abstract

The present disclosure provides a phosphorus-containing and metal-loaded molecular sieve with an MFI structure and a preparation method thereof. The n(SiO ₂ )/n(Al ₂ O ₃ ) of the molecular sieve is greater than 100; the phosphorus content of the molecular sieve is 0.1-5 % by weight; the loaded metal content of the molecular sieve is 0.5-5% by weight; the Al distribution parameter D (Al) of the molecular sieve satisfies: 0.6≤D(Al)≤0.85; the mesopore volume of the molecular sieve accounts for the total pore volume The ratio of the pore size is 40-80% by volume, and the proportion of the mesopore volume with a pore size of 2 nanometers to 20 nanometers to the total mesopore volume is greater than 90% by volume; the ratio of the strong acid content of the molecular sieve to the total acid content is 60-80%. , the ratio of the amount of B acid to the amount of L acid is 15‑80. The phosphorus-containing and metal-loaded MFI structural molecular sieve of the present disclosure is used as an active component to prepare a catalyst or an auxiliary agent, which can effectively reduce the olefin content of gasoline while increasing the gasoline yield and octane number in the catalytic cracking reaction of petroleum hydrocarbons .

Description

A kind of phosphorus-containing and metal-loaded MFI structure molecular sieve and preparation method thereof

technical field

The present disclosure relates to a phosphorus-containing and metal-supported MFI molecular sieve and a preparation method thereof.

Background technique

With the continuous upgrading of gasoline standards in my country, the control of olefin content in gasoline is becoming increasingly strict. The current National IV standard limits the olefin content of gasoline to a volume fraction of not higher than 28%, and the National V gasoline standard further reduces the olefin content to a volume fraction of not higher than 24%. In developed countries such as Europe and the United States, gasoline standards are more stringent on the olefin content. For example, the California 3 standard limits the gasoline olefin content to no more than 6% by volume, and the Euro 5 standard does not exceed 18%.

FCC gasoline accounts for more than 60% of the gasoline pool in my country, and the high olefin content in FCC gasoline has become one of the bottlenecks for it to enter the gasoline pool. In the context of improving the yield of light oil, the catalytic cracking gas oil (FGO) selective hydrotreating process and selective catalytic cracking (moderate cracking technology) process integration technology developed by the Academy of Petroleum Science and Technology ( IHCC) can greatly increase the yield of light oil (more than 8%), but the olefin content of IHCC process gasoline fraction is higher than that of conventional FCC (up to 55%), so reducing the olefin content of FCC gasoline has become a top priority.

ZSM-5 molecular sieve has shape-selective cracking and isomerization effects, and can be flexibly used in catalytic cracking catalysts or additives to effectively increase the octane number of catalytic cracking gasoline. ZSM-5 molecular sieve is a three-dimensional mesoporous high-silicon molecular sieve that was first successfully prepared by Mobil Company. There are ten-membered ring channels in the [100] and [010] directions, and the pore diameter is about 0.51nm×0.55nm and 0.53nm×0.56nm. Especially the unique Z channel in the [100] direction leads to its highly efficient shape-selective catalytic properties. Allow straight-chain alkanes to enter while restricting multi-side-chain hydrocarbons and cyclic hydrocarbons, preferentially crack low-octane alkanes and olefins in gasoline into C3 and C4 olefins, and isomerize straight-chain olefins into high-end olefins with more side chains octane olefins. ZSM-5 molecular sieve is used in catalytic cracking catalyst, on the one hand, it improves the yield of liquefied gas and the concentration of propylene in liquefied gas, and on the other hand, it increases the octane number of gasoline. However, due to the conversion of some gasoline olefins into liquefied gas, it will inevitably lead to the loss of gasoline yield. In order to produce high-octane gasoline, it is necessary to modify the ZSM-5 molecular sieve to reduce the cracking ability and improve the aromatization ability. The olefinic components in are transformed into aromatic hydrocarbon components.

Chinese patent CN1080313A discloses a catalytic reforming-aromatization method for inferior gasoline. The catalyst is Zn-Al or Zn-Al-rare earth modified HZSM-5 zeolite, and aluminum oxide or silicon oxide is used as a binder. This technology adopts a two-stage reaction device. The first-stage reactor makes the raw material and the catalyst contact and react under the conditions of no hydrogen, 300-550°C, 0.05-1.2MPa, and a weight hourly space velocity of 0.2-10. Liquid separation, fractionation after discharge of liquid above _C5 , and then sending the obtained gasoline fraction into the second stage reactor, under the conditions of 0.05~1.5MPa, volume space velocity 20~2000, bed temperature 480~650℃ Aromatization reaction, the reaction product is separated by gas and liquid to obtain aromatic hydrocarbon mixture and gas rich in hydrogen.

Chinese patent CN 1212376A discloses a non-hydrogenation upgrading catalyst for light hydrocarbons and its preparation method and application, which relates to a non-hydrogenation upgrading catalyst for C ₃ -C ₁₁ light hydrocarbon mixtures, including 0.1-5.0% by mass of Mixed rare earth oxide or antimony oxide, 95.0-99.1% by mass of carrier, the carrier is composed of 50-80% by mass of HZSM-5 zeolite and 20-50% by mass of gamma-alumina. The catalyst is used for upgrading low-octane gasoline to increase gasoline octane and reduce olefin content.

Chinese patent CN 1651141A discloses an aromatization catalyst and its preparation method and application. Modified ZSM-5 and Y-type molecular sieves are used as active components, the modified elements are zinc, phosphorus and rare earth metals, and the Y molecular sieve is REY Or high-silicon Y, with aluminum sol or silica sol as a binder, and roll forming a small ball catalyst with a diameter of 1.4 to 2.0 mm. The catalyst is applied in a moving bed reactor to realize the continuous aromatization reaction of low-octane gasoline or naphtha. This method can maintain a relatively stable product yield and distribution, but the dry gas yield is still high, and the equipment investment is relatively large.

In order to reduce the cracking ability of ZSM-5 molecular sieve and reduce gasoline loss as much as possible, increasing the silicon-aluminum ratio is an effective modification method.

Chinese patent CN 101269340A discloses a ZSM-5 zeolite catalyst with a high silicon-to-aluminum ratio and a preparation method thereof. The catalyst is prepared by using active pure silicon compound as a silicon source, adding a small amount of aluminum, and hydrothermal synthesis. The silicon-aluminum ratio of the zeolite framework in the catalyst is over 1000, submicron grain particles, open pores, large specific surface area, and good molecular diffusivity.

Chinese patent CN 1046922A discloses a method for increasing the silicon-aluminum ratio of ZSM-5 molecular sieve. The molecular sieve is a molecular sieve with high silicon-aluminum ratio and high crystallinity. It is prepared by hydrothermal treatment under pressure and then acid treatment. There is no or only a small amount of non-skeleton aluminum in the product.

Chinese patent CN 103480411A discloses a mesoporous ZSM-5 molecular sieve catalyst and a preparation method thereof. This disclosure dissolves cheap silicon-aluminum sources, potassium salts and organic templates in water, uses ultrasonic cavitation, heats the system with ultrasonic-assisted mechanical stirring, and utilizes the salting-out effect of potassium salts to produce structure-oriented effects, and finally Mesoporous ZSM-5 molecular sieves with high silicon-to-aluminum ratio synthesized by hydrothermal method.

Chinese patent CN 101857243A discloses a method for adjusting the surface pore size of ZSM-5 molecular sieve by surface dealumination and silicon supplementation. The disclosure uses ammonium fluorosilicate solution to dealuminate and supplement silicon on the surface of ZSM-5 zeolite molecular sieve to realize the surface pore size precise control. Ammonium fluorosilicate is used to modify the ZSM-5 zeolite molecular sieve, and the Al in the molecular sieve surface framework is isomorphously replaced by Si. Since the bond length of Si-O is shorter than that of Al-O, the diameter of the surface pores of the molecular sieve can be reduced. On the surface of the molecular sieve An ultra-thin layer rich in silicon is formed. By finely controlling the treatment conditions, the degree of shrinkage of the pores on the surface of the molecular sieve can be controlled.

In the prior art, the direct synthesis of high silicon-aluminum ratio ZSM-5 molecular sieves requires the use of expensive templates, which is costly, difficult to produce, and high waste discharge, and the synthesized ZSM-5 molecular sieves usually have finer crystal grains (100~ 300nm), and poor hydrothermal stability, it is difficult to popularize and apply in catalytic cracking catalysts.

Contents of the invention

The purpose of the present disclosure is to provide a phosphorus-containing and metal-loaded MFI structural molecular sieve and its preparation method. The phosphorus-containing and metal-loaded MFI structural molecular sieve of the present disclosure is used as an active component to prepare a catalyst or auxiliary agent. In the catalytic cracking reaction, the yield and octane number of gasoline can be increased, and the olefin content of gasoline can be effectively reduced.

In order to achieve the above purpose, the present disclosure provides a phosphorus-containing and _metal -loaded molecular sieve with MFI structure, the molecular sieve's n(SiO ₂ )/n(Al _{2 O 3} ) is greater than 100; Based on the dry basis weight, the phosphorus content of the molecular sieve is 0.1-5% by weight; based on the oxide of the supported metal and based on the dry basis weight of the molecular sieve, the supported metal content of the molecular sieve is 0.5-5% by weight; The Al distribution parameter D(Al) of the molecular sieve satisfies: 0.6≤D(Al)≤0.85, wherein, D(Al)=Al(S)/Al(C), and Al(S) means that it is determined by TEM-EDS method The aluminum content of any area larger than 100 square nanometers within the distance H from the edge of the crystal plane of the molecular sieve grain, Al(C) means that the geometric center of the crystal plane of the molecular sieve grain measured by the TEM-EDS method is within the distance H from the outside The aluminum content in any area larger than 100 square nanometers, wherein the H is 10% of the distance from a certain point on the edge of the crystal plane to the geometric center of the crystal plane; the loaded metal distribution parameter D(M) of the molecular sieve satisfies: 2≤D (M)≤10, wherein, D(M)=M(S)/M(C), M(S) means that the crystal plane edge of the molecular sieve grain measured by the TEM-EDS method is greater than 100 at any time within the H distance The loaded metal content in the square nanometer area, M (C) represents the loaded metal content in any area greater than 100 square nanometers in the distance H from the geometric center of the crystal plane of the molecular sieve grain measured by the TEM-EDS method; The proportion of the mesopore volume to the total pore volume is 40-80% by volume, and the proportion of the mesopore volume with a pore diameter of 2 nm to 20 nm to the total mesopore volume is greater than 90% by volume; the strong acid content of the molecular sieve accounts for the total acid content The proportion of acid is 60-80%, and the ratio of acid amount of B acid to acid amount of L acid is 15-80.

Preferably, _the n(SiO ₂ )/n(Al ₂ O ₃ ) of the molecular sieve is greater than 120; the phosphorus content of _the molecular sieve is 0.2-4 wt. %; based on the oxide of the loaded metal and based on the dry basis weight of the molecular sieve, the loaded metal content of the molecular sieve is 0.5-3% by weight; the Al distribution parameter D (Al) of the molecular sieve satisfies: 0.65≤D( Al)≤0.8; the loaded metal distribution parameter D(M) of the molecular sieve satisfies: 3≤D(M)≤6; the mesopore volume of the molecular sieve accounts for 50-70 volume % of the total pore volume, and the aperture is The proportion of the mesopore volume from 2 nanometers to 20 nanometers to the total mesopore volume is greater than 92%; the strong acid content of the molecular sieve accounts for 65-75% of the total acid content, and the ratio between the acid content of B acid and the acid content of L acid is The ratio is 20-50.

Preferably, the supported metal is zinc and/or gallium.

Preferably, the mesopore is a molecular sieve channel with a pore size greater than 2 nanometers and less than 100 nanometers; the ratio of the strong acid content of the molecular sieve to the total acid content is measured by the NH ₃ -TPD method, and the acid center of the strong acid is NH ₃ The acid center corresponding to the desorption temperature is higher than 300°C; the ratio of the acid amount of B acid to the acid amount of L acid is measured by pyridine adsorption infrared acid method.

The present disclosure also provides a method for preparing the phosphorus-containing and metal-loaded MFI molecular sieve provided in the present disclosure, the preparation method comprising: a. After filtering and washing the MFI molecular sieve slurry obtained by crystallization, to obtain a water-washed molecular sieve; Wherein, based on sodium oxide and the total dry weight of the washed molecular sieve, the sodium content of the washed molecular sieve is less than 3% by weight; b, the water-washed molecular sieve obtained in step a is desiliconized in an alkaline solution, and carried out After filtering and washing, desiliconized molecular sieves are obtained; c, the desiliconized molecular sieves obtained in step b are subjected to ammonium exchange treatment to obtain ammonium exchanged molecular sieves; wherein, in terms of sodium oxide and based on the total dry basis weight of ammonium exchanged molecular sieves, the obtained The sodium content of the ammonium-exchanged molecular sieve is less than 0.2% by weight; d, the ammonium-exchanged molecular sieve obtained in step c is dealuminated in a complex acid dealumination agent solution composed of fluosilicic acid, organic acid and inorganic acid, and filtered After washing and washing, the dealuminated molecular sieve is obtained; e, after the dealuminated molecular sieve obtained in step d is subjected to phosphorus modification treatment and loaded metal loading treatment, a modified molecular sieve is obtained; f, the modified molecular sieve obtained in step e is subjected to water Thermal calcination treatment to obtain the phosphorus-containing and metal-loaded molecular sieve with MFI structure.

Preferably, the alkaline solution in step b is sodium hydroxide solution and/or potassium hydroxide solution.

Preferably, the conditions of the desiliconization treatment in step b include: the weight ratio of the molecular sieve to the alkali in the alkali solution on a dry basis is 1: (0.1-1); the temperature of the desilication treatment is 25-100°C , the time is 15 minutes-8 hours.

Preferably, the conditions of the desiliconization treatment in step b include: the weight ratio of the molecular sieve to the alkali in the alkali solution is 1: (0.15-0.4) in terms of dry weight.

Preferably, the step of dealumination in step d further includes: first mixing an organic acid with the ammonium-exchanged molecular sieve, and then mixing fluosilicic acid and inorganic acid with the ammonium-exchanged molecular sieve.

Preferably, the organic acid in step d is at least one selected from ethylenediaminetetraacetic acid, oxalic acid, citric acid and sulfosalicylic acid, and the inorganic acid is at least one selected from hydrochloric acid, sulfuric acid and nitric acid A sort of.

Preferably, the organic acid in step d is oxalic acid, and the inorganic acid is hydrochloric acid.

Preferably, the conditions of the dealumination treatment described in step d include: the weight ratio of molecular sieve, fluosilicic acid, organic acid and inorganic acid on a dry weight basis is 1: (0.02-0.5): (0.05-0.5) :(0.05-0.5); the treatment temperature is 25-100°C, and the treatment time is 0.5-6 hours.

Preferably, the conditions of the dealumination treatment described in step d include: the weight ratio of molecular sieve, fluosilicic acid, organic acid and inorganic acid on a dry weight basis is 1: (0.05-0.3): (0.1-0.3) :(0.1-0.3).

Preferably, the phosphorus modification treatment in step e includes: impregnating and/or ion-exchanging molecular sieves with at least one phosphorus-containing compound selected from phosphoric acid, ammonium hydrogen phosphate, ammonium dihydrogen phosphate and ammonium phosphate.

Preferably, the loading treatment of the loaded metal in step e includes: dissolving a soluble salt containing at least one loaded metal selected from zinc and gallium in deionized water, adjusting the pH value with ammonia water to make the loaded metal form a hydroxide The morphology was precipitated, and then the resulting precipitate was mixed with molecular sieves to homogeneity.

Preferably, the conditions of the hydrothermal calcination treatment in step f include: the atmosphere of the calcination treatment is a water vapor atmosphere; the calcination temperature is 400-800° C., and the calcination time is 0.5-8 hours.

The inventors of the present disclosure unexpectedly found that the MFI structural molecular sieves were desiliconized and ammonium exchanged by chemical methods, then dealuminated, and finally phosphorus modified, metal loaded and hydrothermally roasted. The phosphorus and the MFI structural molecular sieve containing loaded metal can be applied in catalytic cracking process as active components of catalyst or auxiliary agent.

The molecular sieve with MFI structure provided by the disclosure has a high silicon-aluminum ratio and low total acid content, which can reduce cracking activity; the silicon-rich surface can inhibit the occurrence of non-selective side reactions on the surface; the rich mesopores are beneficial to the synthesis of aromatization reaction intermediates and products Generation and diffusion, reducing coking deactivation; high ratio of strong acid centers and high ratio of B acid/L acid, which is conducive to the progress of isomerization reaction and aromatization reaction; the surface-enriched supported metals can damage the molecular sieve pores as little as possible On the premise of acidic centers, the aromatization performance of molecular sieves is further strengthened, which can reduce the olefin content in gasoline and increase the aromatic content.

The present disclosure provides phosphorus-containing and metal-loaded molecular sieves with MFI structures, which have the characteristics of weak cracking ability and strong aromatization ability, and can be used as catalytic cracking materials for catalytic cracking, which can reduce the olefin content in gasoline while increasing gasoline yield, increase The content of aromatics in gasoline keeps gasoline octane number from decreasing or increasing.

Other features and advantages of the present disclosure will be described in detail in the detailed description that follows.

Detailed ways

Specific embodiments of the present disclosure 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 disclosure, and are not intended to limit the present disclosure.

The present disclosure provides a phosphorus-containing and metal-loaded molecular sieve with an MFI structure, and the molecular sieve has n(SiO ₂ )/n(Al ₂ O ₃ ) greater than 100; calculated as P ₂ O ₅ and based on the dry weight of the molecular sieve , the phosphorus content of the molecular sieve is 0.1-5% by weight; based on the oxide of the loaded metal and based on the dry weight of the molecular sieve, the loaded metal content of the molecular sieve is 0.5-5% by weight; the Al of the molecular sieve The distribution parameter D(Al) satisfies: 0.6≤D(Al)≤0.85, wherein, D(Al)=Al(S)/Al(C), and Al(S) represents the molecular sieve grain density measured by TEM-EDS method The aluminum content in any area greater than 100 square nanometers within the distance H from the edge of the crystal plane, Al(C) means that the geometric center of the crystal plane measured by the TEM-EDS method is greater than 100 square nanometers within the distance H from the geometric center of the crystal plane The aluminum content of the area, wherein the H is 10% of the distance from a certain point on the edge of the crystal plane to the geometric center of the crystal plane; the loaded metal distribution parameter D(M) of the molecular sieve satisfies: 2≤D(M)≤10 , wherein, D(M)=M(S)/M(C), M(S) represents the load of any region larger than 100 square nanometers within the distance H from the edge of the molecular sieve grain measured by the TEM-EDS method Metal content, M (C) represents the loaded metal content in any region greater than 100 square nanometers within the distance H from the geometric center of the crystal plane of the molecular sieve grain measured by the TEM-EDS method; the mesopore volume of the molecular sieve accounts for the total The ratio of the pore volume is 40-80% by volume, and the proportion of the mesopore volume with a pore diameter of 2 nm to 20 nm to the total mesoporous volume is greater than 90% by volume; the ratio of the strong acid amount of the molecular sieve to the total acid amount is 60- 80%, the ratio of the amount of B acid to the amount of L acid is 15-80; preferably, the n(SiO ₂ )/n(Al ₂ O ₃ ) of the molecular sieve is greater than 120; calculated as P ₂ O ₅ and expressed as The molecular sieve is based on the dry basis weight, and the phosphorus content of the molecular sieve is 0.2-4% by weight; based on the oxide of the loaded metal and based on the dry basis weight of the molecular sieve, the loaded metal content of the molecular sieve is 0.5-3% by weight. %; the Al distribution parameter D(Al) of the molecular sieve satisfies: 0.65≤D(Al)≤0.8; the loaded metal distribution parameter D(M) of the molecular sieve satisfies: 3≤D(M)≤6; the molecular sieve The proportion of the mesopore volume in the total pore volume is 50-70%, and the proportion of the mesopore volume with a pore diameter of 2 nm to 20 nm in the total mesopore volume is greater than 92%; the strong acid content of the molecular sieve accounts for the total acid The ratio of the amount is 65-75%, and the ratio of the acid amount of B acid to the amount of L acid is 20-50.

According to the present disclosure, the supported metal refers to the metal loaded on the molecular sieve by means of loading, excluding alkali metals such as aluminum, sodium, and potassium, which may be zinc and/or gallium, or other metals, which are not included in this disclosure. limit.

According to the present disclosure, it is well known to those skilled in the art to use the TEM-EDS method to determine the aluminum content and supported metal content of molecular sieves, wherein the geometric center is also well known to those skilled in the art, and can be calculated according to the formula. The present disclosure does not Repeat again, the geometric center of the general symmetric figure is the intersection point of each relative vertex line, for example, the geometric center of the hexagonal crystal face of the conventional hexagonal sheet ZSM-5 molecular sieve is at the intersection of three relative vertex lines, said The crystal plane is a plane of regular crystal grains, and the inward and outward directions both refer to the inward and outward directions on the crystal plane.

According to the present disclosure, the ratio of the mesoporous volume of the molecular sieve to the total pore volume is measured by nitrogen adsorption BET pore volume measurement method, the mesoporous volume is the pore volume with a pore diameter greater than 2 nanometers and less than 100 nanometers; the strong acid of the molecular sieve The ratio of the acid amount to the total acid amount is measured by the NH ₃ -TPD method, the acid center of the strong acid is the acid center corresponding to the NH ₃ desorption temperature greater than 300°C; the ratio of the acid amount of the B acid to the acid amount of the L acid The ratio was measured by pyridine adsorption infrared acid method.

The present disclosure also provides a method for preparing the phosphorus-containing and metal-loaded MFI molecular sieve provided in the present disclosure, the preparation method comprising: a. After filtering and washing the MFI molecular sieve slurry obtained by crystallization, to obtain a water-washed molecular sieve; Wherein, based on sodium oxide and the total dry weight of the washed molecular sieve, the sodium content of the washed molecular sieve is less than 3% by weight; b, the water-washed molecular sieve obtained in step a is desiliconized in an alkaline solution, and carried out After filtering and washing, desiliconized molecular sieves are obtained; c, the desiliconized molecular sieves obtained in step b are subjected to ammonium exchange treatment to obtain ammonium exchanged molecular sieves; wherein, in terms of sodium oxide and based on the total dry basis weight of ammonium exchanged molecular sieves, the obtained The sodium content of the ammonium-exchanged molecular sieve is less than 0.2% by weight; d, the ammonium-exchanged molecular sieve obtained in step c is dealuminated in a complex acid dealumination agent solution composed of fluosilicic acid, organic acid and inorganic acid, and filtered After washing and washing, the dealuminated molecular sieve is obtained; e, after the dealuminated molecular sieve obtained in step d is subjected to phosphorus modification treatment and loaded metal loading treatment, a modified molecular sieve is obtained; f, the modified molecular sieve obtained in step e is subjected to water Thermal calcination treatment to obtain the phosphorus-containing and metal-loaded molecular sieve with MFI structure.

According to the present disclosure, the MFI structure molecular sieve slurry obtained by crystallization is well known to those skilled in the art, and will not be described in detail in the present disclosure, wherein the MFI structure molecular sieve is also well known to those skilled in the art, and can be obtained by crystallization without amine, or it can be Molecular sieves prepared by the template method, wherein the molecular sieves obtained by crystallization without amine do not need to be roasted, and the molecular sieves prepared by the template method need to be dried and then roasted in the air. The silicon-aluminum ratio of ZSM-5 molecular sieves is generally less than 100.

According to the present disclosure, the use of alkaline solution for desiliconization is well known to those skilled in the art. The alkaline solution in step b can be selected from sodium hydroxide solution and/or potassium hydroxide solution, preferably sodium hydroxide solution, The conditions of the desiliconization treatment may include: the weight ratio of the molecular sieve on a dry basis to the alkali in the alkali solution is 1: (0.1-1), preferably 1: (0.15-0.4); the temperature of the desilication treatment The temperature is from room temperature to 100°C, preferably 50-85°C, and the time is 15 minutes to 8 hours, preferably 30 minutes to 4 hours.

According to the present disclosure, ammonium exchange treatment is well known to those skilled in the art. For example, in step c, the desiliconized molecular sieve after alkali treatment can be treated according to molecular sieve: ammonium salt: H ₂ O = 1: (0.1-1): (5 -10) The weight ratio is exchanged at room temperature to 100° C. for 0.5-2 hours and then filtered, so that the Na ₂ O content on the zeolite is less than 0.2 wt%. The ammonium salt may be a common inorganic ammonium salt, for example, at least one selected from ammonium chloride, ammonium sulfate and ammonium nitrate.

According to the present disclosure, the organic acid and inorganic acid described in step d are well known to those skilled in the art, for example, the organic acid can be selected from ethylenediaminetetraacetic acid, oxalic acid, citric acid and sulfosalicylic acid At least one of, preferably oxalic acid; the inorganic acid can be at least one selected from hydrochloric acid, sulfuric acid and nitric acid, preferably hydrochloric acid.

According to the present disclosure, the dealumination treatment in step d is well known to those skilled in the art, but it has not been reported that inorganic acid, organic acid and fluorosilicic acid are used together for dealumination treatment. The dealumination treatment can be carried out once or several times. The organic acid can be mixed with the ammonium-exchanged molecular sieve first, and then fluosilicic acid and inorganic acid can be mixed with the ammonium-exchanged molecular sieve, that is, the organic acid can be added first. Ammonium exchanged molecular sieves, then slowly add fluosilicic acid and inorganic acid in parallel flow, or add fluosilicic acid first and then add inorganic acid, preferably fluosilicic acid and inorganic acid add slowly in parallel flow. The conditions of the dealumination treatment can be: the weight ratio of molecular sieve, fluosilicic acid, organic acid and inorganic acid based on dry weight is 1: (0.02-0.5): (0.05-0.5): (0.05-0.5 ), preferably 1:(0.05-0.3):(0.1-0.3):(0.1-0.3); the treatment temperature is 25-100°C, and the treatment time is 0.5-6 hours.

According to the present disclosure, phosphorus modification treatment and loading treatment of loaded metals are well known to those skilled in the art, and the phosphorus modification treatment described in step e may include: At least one phosphorus-containing compound in ammonium impregnates and/or ion-exchanges the molecular sieve; the loading treatment of the loaded metal described in step e may include: dissolving a soluble salt containing at least one loaded metal selected from zinc and gallium in In deionized water, adjust the pH value with ammonia water to precipitate the loaded metal in the form of hydroxide, and then mix the obtained precipitate with molecular sieves evenly.

According to the present disclosure, hydrothermal calcination treatment is well known to those skilled in the art, and the conditions of hydrothermal calcination treatment in step f can be: the atmosphere of calcination treatment is a water vapor atmosphere; the calcination temperature is 400-800°C, and the calcination time is 0.5-8 hours.

The washing described in the present disclosure is well known to those skilled in the art, and the method may be: rinse the filtered molecular sieve with 5-10 times of water at 30-60°C.

The present disclosure will be further illustrated by the following examples, but the present disclosure is not subject to any limitation thereby. The instruments and reagents used in the examples of the present disclosure, unless otherwise specified, are commonly used instruments and reagents by those skilled in the art .

The effect of molecular sieves on gasoline yield and octane number in catalytic cracking of petroleum hydrocarbons was evaluated by heavy oil micro-reaction. Molecular sieves are used as active components to prepare catalytic cracking additives. The content of molecular sieves is 50%, and the rest are kaolin and alumina carriers. The prepared additive samples are subjected to 800°C, 100% water vapor aging treatment for 17 hours on a fixed bed aging device. Then use a catalytic cracking balancer (from Qilu Catalyst Factory, brand DVI catalyst) that does not contain shape-selective molecular sieves as the base catalyst, and mix it evenly with the auxiliary agent in a weight ratio of 95:5, and then place it on the micro-reactor of the catalytic cracking fluidized bed. For evaluation, the raw material oil is slag-doped VGO, the evaluation conditions are reaction temperature 500°C, regeneration temperature 600°C, agent-oil ratio 5.92. Blank evaluation is 100% FCC balancer.

The micro-reaction conversion rate of the present disclosure is measured by the ASTM D5154-2010 standard method, and the octane number of the micro-reaction product is measured by the RIPP 85-90 method.

The degree of crystallinity in the present disclosure is measured using the standard method of ASTM D5758-2001 (2011) e1.

n(SiO ₂ )/n(Al ₂ O ₃ ) in this disclosure, that is, the ratio of silicon to aluminum is calculated by the content of silicon oxide and aluminum oxide, and the content of silicon oxide and aluminum oxide is measured by the standard method of GB/T 30905-2014 .

The phosphorus content of the present disclosure is measured by the GB/T 30905-2014 standard method, the supported metal content is measured by the GB/T 30905-2014 standard method, and the sodium content is measured by the GB/T 30905-2014 standard method.

For the TEM-EDS determination method of the present disclosure, refer to the research method of solid catalyst, Petrochemical Industry, 29(3), 2000:227.

The assay method of total specific surface area (S _BET ), mesopore volume, total pore volume, 2-20 nanometer mesopore volume of the present disclosure is as follows:

Measured by AS-3 and AS-6 static nitrogen adsorption instruments produced by Quantachrome Instruments.

Instrument parameters: put the sample in the sample processing system, evacuate to 1.33×10 ^-2 Pa at 300°C, keep the temperature and hold the pressure for 4 hours, and purify the sample. At the temperature of liquid nitrogen at -196°C, the adsorption and desorption of nitrogen by the purified samples were tested under different specific pressures P/P ₀ , and the N ₂ adsorption-desorption isotherm curve was obtained. Then use the two-parameter BET formula to calculate the total specific surface area, take the adsorption capacity below the specific pressure P/P ₀ = 0.98 as the total pore volume of the sample, use the BJH formula to calculate the pore size distribution of the mesoporous part, and use the integral method to calculate the mesopore Volume (2-100 nm) and Mesopore Volume 2-20 nm.

The measuring method of B acid amount and L acid amount of the present disclosure is as follows:

The FTS3000 Fourier transform infrared spectrometer produced by the American BIO-RAD company was used.

Test conditions: After the sample is pressed into a tablet, it is placed in the in-situ cell of the infrared spectrometer and sealed, vacuumed to 10 ^-3 Pa at 350°C, and kept for 1 hour to desorb the gas molecules on the surface of the sample, and then cooled to room temperature. Introduce pyridine vapor with a pressure of 2.67Pa into the in-situ cell. After equilibrating for 30 minutes, heat up to 200°C, evacuate again to 10 ^-3 Pa, keep for 30 minutes, cool to room temperature, and scan in the range of 1400-1700cm ^-1 wave number. Record the infrared spectrum of pyridine adsorption at 200°C. Then move the sample in the infrared absorption cell to the heat treatment area, raise the temperature to 350°C, evacuate to 10 ^-3 Pa, keep it for 30min, cool to room temperature, and record the infrared spectrum of pyridine adsorption at 350°C. The instrument automatically integrates to obtain the acidity of B acid and the acidity of L acid.

The assay method of total acid content and strong acid acid content of the present disclosure is as follows:

The Autochem II 2920 temperature-programmed desorption instrument from Mike Company of the United States was used.

Test conditions: Weigh 0.2g of the sample to be tested and put it into the sample tube, place it in the heating furnace of the thermal conductivity cell, use He gas as the carrier gas (50mL/min), raise the temperature to 600°C at a rate of 20°C/min, and purge for 60min to remove Impurities adsorbed on the catalyst surface. Then lower the temperature to 100°C, keep the temperature constant for 30 minutes, switch to NH ₃ -He mixed gas (10.02% NH ₃ +89.98% He) for adsorption for 30 minutes, and then continue purging with He gas for 90 minutes until the baseline is stable to desorb the physically adsorbed ammonia . Raise the temperature to 600°C at a heating rate of 10°C/min for desorption, keep for 30min, and the desorption ends. A TCD detector is used to detect changes in gas components, and the instrument automatically integrates to obtain the total acid content and strong acid content. The acid center of a strong acid is the acid center corresponding to the NH ₃ desorption temperature greater than 300°C.

For details of the RIPP standard method described in the present disclosure, please refer to "Petrochemical Analysis Methods", edited by Yang Cuiding et al., 1990 edition.

The calculation method of the D value is as follows: a polygon is formed by selecting a crystal grain and a certain crystal face of the crystal grain in the transmission electron microscope, and the polygon has a geometric center, an edge, and a 10% distance H from the geometric center to a certain point on the edge (different The edge point of the crystal plane, the H value is different), select any area larger than 100 square nanometers within the distance H from the edge of the crystal plane and any area larger than 100 square nanometers within the distance H from the geometric center of the crystal plane to determine the aluminum content , that is, Al(S1) and Al(C1), and calculate D(Al)1=Al(S1)/Al(C1), select different grains for measurement 5 times, and calculate the average value as D(Al) , The determination method of D(M) is similar to that of D(Al).

Example 1

The crystallized ZSM-5 molecular sieve (produced by Catalyst Qilu Branch, synthesized by amine-free method, n(SiO ₂ )/n(Al ₂ O ₃ )=27) was filtered to remove the mother liquor, washed with water until the Na ₂ O content was lower than 3.0 % by weight, filtered to obtain a filter cake; get the above-mentioned molecular sieve 100g (dry basis) and add in 1000g 2.0% NaOH solution, heat up to 65°C, react for 30min, after cooling to room temperature rapidly, filter, wash until the filtrate is neutral. Then, add 800g of water to the filter cake to make a slurry, add 40g of NH ₄ Cl, heat up to 75°C, exchange treatment for 1 hour until the Na ₂ O content is less than 0.2% by weight, filter and wash to obtain a molecular sieve filter cake; take 50g of the above molecular sieve (Dry basis) Add water to prepare a molecular sieve slurry with a solid content of 10% by weight, add 11g of oxalic acid during stirring, then add 110g of hydrochloric acid (10% by mass fraction) and 92g of fluosilicic acid (3% by mass fraction) in parallel, and the addition time is 30min ; Stir at a constant temperature of 65°C for 1 hour, filter and wash until the filtrate is neutral; add water to the filter cake and beat to obtain a molecular sieve slurry with a solid content of 45% by weight; mix 1.2g H ₃ PO ₄ (concentration 85% by weight) and 3.3g Zn(NO ₃ ) ₂ ·6H ₂ O was dissolved in 10g of water, and ammonia water was added to adjust the pH=6, then added to the molecular sieve slurry, mixed evenly, dried, and calcined at 550°C for 2 hours in a 100% steam atmosphere. Molecular sieve A was obtained, and the physical and chemical properties, micro-reaction evaluation gasoline yield and octane number data are listed in Table 1.

Comparative example 1

The crystallized ZSM-5 molecular sieve (produced by Catalyst Qilu Branch, synthesized by amine-free method, n(SiO ₂ )/n(Al ₂ O ₃ )=27) was filtered to remove the mother liquor, washed with water until the Na ₂ O content was lower than 3.0 % by weight, filtered to obtain a filter cake; get the above-mentioned molecular sieve 100g (dry basis) and add in 1000g 2.0% NaOH solution, heat up to 65°C, react for 30min, after cooling to room temperature rapidly, filter, wash until the filtrate is neutral. Then, add 800g of water to the filter cake to make a slurry, add 40g of NH ₄ Cl, heat up to 75°C, exchange treatment for 1 hour until the Na ₂ O content is less than 0.2% by weight, filter and wash to obtain a molecular sieve filter cake; take 50g of the above molecular sieve (Dry basis) Add water to prepare a molecular sieve slurry with a solid content of 10% by weight, add 11g of oxalic acid during stirring, then add 110g of hydrochloric acid (10% by mass fraction) and 92g of fluosilicic acid (3% by mass fraction) in parallel, and the addition time is 30min ; Stir at a constant temperature of 65°C for 1 hour, filter and wash until the filtrate is neutral; add water to the filter cake and beat to obtain a molecular sieve slurry with a solid content of 40% by weight, add 1.2g H ₃ PO ₄ (concentration 85% by weight) and 3.3g Zn(NO ₃ ) ₂ ·6H ₂ O, mixed uniformly, impregnated, dried, and roasted at 550°C for 2 hours. The molecular sieve DA1 was obtained, and the physical and chemical properties, micro-reaction evaluation gasoline yield and octane number data are listed in Table 1.

Comparative example 2

The crystallized ZSM-5 molecular sieve (produced by Catalyst Qilu Branch, synthesized by amine-free method, n(SiO ₂ )/n(Al ₂ O ₃ )=27) was filtered to remove the mother liquor, washed with water until the Na ₂ O content was lower than 3.0 % by weight, filtered to obtain a filter cake; get the above-mentioned molecular sieve 100g (dry basis) and add in 1000g 2.0% NaOH solution, heat up to 65°C, react for 30min, after cooling to room temperature rapidly, filter, wash until the filtrate is neutral. Then, add 800g of water to the filter cake to make a slurry, add 40g of NH ₄ Cl, heat up to 75°C, exchange treatment for 1 hour until the Na ₂ O content is less than 0.2% by weight, filter and wash to obtain a molecular sieve filter cake; take 50g of the above molecular sieve (dry basis) add water to prepare a molecular sieve slurry with a solid content of 10% by weight, add 27g of oxalic acid during stirring; heat up to 65°C and stir at a constant temperature for 1h, filter and wash until the filtrate is neutral; add water to the filter cake and beat to obtain a slurry with a solid content of 40% by weight. Add 1.2g of H ₃ PO ₄ (concentration: 85% by weight) and 3.3g of Zn(NO ₃ ) ₂ ·6H ₂ O to the molecular sieve slurry, uniformly mix and impregnate, dry, and roast at 550°C for 2 hours. The molecular sieve DA2 was obtained, and the physical and chemical properties, micro-reaction evaluation gasoline yield and octane number data are listed in Table 1.

Comparative example 3

The crystallized ZSM-5 molecular sieve (produced by Catalyst Qilu Branch, synthesized by amine-free method, n(SiO ₂ )/n(Al ₂ O ₃ )=27) was filtered to remove the mother liquor, washed with water until the Na ₂ O content was lower than 3.0 % by weight, filtered to obtain a filter cake; get the above-mentioned molecular sieve 100g (dry basis) and add in 1000g 2.0% NaOH solution, heat up to 65°C, react for 30min, after cooling to room temperature rapidly, filter, wash until the filtrate is neutral. Then, take 50 g (dry basis) of the above-mentioned molecular sieve and add water to prepare a molecular sieve slurry with a solid content of 10% by weight, add 215 g of hydrochloric acid (10% by mass fraction) during stirring; heat up to 65° C. and stir at a constant temperature for 1 hour, filter and wash until the filtrate is neutral; Add 1500g of water to the cake for beating, add 80g of NH ₄ Cl and raise the temperature to 65°C for exchange and washing for 40 minutes, filter and rinse until the filtrate is neutral; add water to the filter cake to get a molecular sieve slurry with a solid content of 40% by weight, add 1.2g of H ₃ PO ₄ (concentration: 85% by weight) and 3.3g of Zn(NO ₃ ) ₂ ·6H ₂ O, mixed evenly, impregnated, dried, and roasted at 550°C for 2 hours. The molecular sieve DA3 was obtained, and the physical and chemical properties, micro-reaction evaluation gasoline yield and octane number data are listed in Table 1.

Comparative example 4

The crystallized ZSM-5 molecular sieve (produced by Catalyst Qilu Branch, synthesized by amine-free method, n(SiO ₂ )/n(Al ₂ O ₃ )=27) was filtered to remove the mother liquor, washed with water until the Na ₂ O content was lower than 3.0 % by weight, filtered to obtain a filter cake; get the above-mentioned molecular sieve 100g (dry basis) and add in 1000g 2.0% NaOH solution, heat up to 65°C, react for 30min, after cooling to room temperature rapidly, filter, wash until the filtrate is neutral. Then, add 800g of water to the filter cake to make a slurry, add 40g of NH ₄ Cl, heat up to 75°C, exchange treatment for 1 hour until the Na ₂ O content is less than 0.2% by weight, filter and wash to obtain a molecular sieve filter cake; take 50g of the above molecular sieve (dry basis) add water to prepare a molecular sieve slurry with a solid content of 10% by weight, add 370g of fluosilicic acid (3% by mass) during stirring, and add for 30min; heat up to 65°C and stir for 1h at a constant temperature, filter and wash until the filtrate is neutral; The filter cake was beaten with water to obtain a molecular sieve slurry with a solid content of 40% by weight, adding 1.2gH ₃ PO ₄ (concentration 85% by weight) and 3.3gZn(NO ₃ ) ₂ 6H ₂ O, mixed uniformly, impregnated, dried, and roasted at 550°C Process for 2 hours. The molecular sieve DA4 was obtained, and the physical and chemical properties, micro-reaction evaluation gasoline yield and octane number data are listed in Table 1.

Comparative example 5

The crystallized ZSM-5 molecular sieve (produced by Catalyst Qilu Branch, synthesized by amine-free method, n(SiO ₂ )/n(Al ₂ O ₃ )=27) was filtered to remove the mother liquor, washed with water until the Na ₂ O content was lower than 3.0 % by weight, filtered to obtain a filter cake; get the above-mentioned molecular sieve 100g (dry basis) and add in 1000g 2.0% NaOH solution, heat up to 65°C, react for 30min, after cooling to room temperature rapidly, filter, wash until the filtrate is neutral. Then, add 800g of water to the filter cake to make a slurry, add 40g of NH ₄ Cl, heat up to 75°C, exchange treatment for 1 hour until the Na ₂ O content is less than 0.2% by weight, filter and wash to obtain a molecular sieve filter cake; take 50g of the above molecular sieve (dry basis) add water to prepare molecular sieve slurry with solid content of 10% by weight, add 11g of oxalic acid during stirring, then add 110g of hydrochloric acid (10% by mass) for 30min; heat up to 65°C and stir for 1h, filter and wash with water until the filtrate Neutral; add water to the filter cake and beat to obtain a molecular sieve slurry with a solid content of 40% by weight, add 1.2gH ₃ PO ₄ (concentration 85% by weight) and 3.3gZn(NO ₃ ) ₂ 6H ₂ O, mix evenly, impregnate, and dry , 550 ° C roasting treatment for 2 hours. The molecular sieve DA5 was obtained, and the physical and chemical properties, micro-reaction evaluation gasoline yield and octane number data are listed in Table 1.

Comparative example 6

The crystallized ZSM-5 molecular sieve (produced by Catalyst Qilu Branch, synthesized by amine-free method, n(SiO ₂ )/n(Al ₂ O ₃ )=27) was filtered to remove the mother liquor, washed with water until the Na ₂ O content was lower than 3.0 % by weight, filtered to obtain a filter cake; get the above-mentioned molecular sieve 100g (dry basis) and add in 1000g 2.0% NaOH solution, heat up to 65°C, react for 30min, after cooling to room temperature rapidly, filter, wash until the filtrate is neutral. Then, add 800g of water to the filter cake to make a slurry, add 40g of NH ₄ Cl, heat up to 75°C, exchange treatment for 1 hour until the Na ₂ O content is less than 0.2% by weight, filter and wash to obtain a molecular sieve filter cake; take 50g of the above molecular sieve (Dry basis) Add water to prepare molecular sieve slurry with solid content of 10% by weight, add 11g of oxalic acid during stirring, then slowly add 184g of fluosilicic acid (3% by mass) for 30min; heat up to 65°C and stir for 1h, filter Wash with water until the filtrate is neutral; add water to the filter cake and beat to obtain a molecular sieve slurry with a solid content of 40% by weight, add 1.2gH ₃ PO ₄ (concentration 85% by weight) and 3.3gZn(NO ₃ ) ₂ 6H ₂ O, mix and impregnate evenly , drying, and calcination at 550°C for 2 hours. The molecular sieve DA6 was obtained, and the physical and chemical properties, micro-reaction evaluation gasoline yield and octane number data are listed in Table 1.

Comparative example 7

The crystallized ZSM-5 molecular sieve (produced by Catalyst Qilu Branch, synthesized by amine-free method, n(SiO ₂ )/n(Al ₂ O ₃ )=27) was filtered to remove the mother liquor, washed with water until the Na ₂ O content was lower than 3.0 % by weight, filtered to obtain a filter cake; get the above-mentioned molecular sieve 100g (dry basis) and add in 1000g 2.0% NaOH solution, heat up to 65°C, react for 30min, after cooling to room temperature rapidly, filter, wash until the filtrate is neutral. Then, add 800g of water to the filter cake to make a slurry, add 40g of NH ₄ Cl, heat up to 75°C, exchange treatment for 1 hour until the Na ₂ O content is less than 0.2% by weight, filter and wash to obtain a molecular sieve filter cake; take 50g of the above molecular sieve (dry basis) add water to prepare a molecular sieve slurry with a solid content of 10% by weight, add 110g of hydrochloric acid (10% by mass fraction) and 184g of fluosilicic acid (3% by mass) under stirring, and add it for 30 minutes; heat up to 65°C Stir at constant temperature for 1 hour, filter and wash with water until the filtrate is neutral; add water to the filter cake and beat to obtain a molecular sieve slurry with a solid content of 40% by weight, add 1.2gH ₃ PO ₄ (concentration: 85% by weight) and 3.3gZn(NO ₃ ) ₂ ·6H ₂ O, homogeneously mixed dipping, drying, 550 ℃ roasting treatment for 2 hours. The molecular sieve DA7 was obtained, and the physical and chemical properties, micro-reaction evaluation gasoline yield and octane number data are listed in Table 1.

Comparative example 8

The crystallized ZSM-5 molecular sieve (produced by Catalyst Qilu Branch, synthesized by amine-free method, n(SiO ₂ )/n(Al ₂ O ₃ )=27) was filtered to remove the mother liquor, washed with water until the Na ₂ O content was lower than 3.0 % by weight, filtered to obtain a filter cake; get the above-mentioned molecular sieve 100g (dry basis) and add in 1000g 2.0% NaOH solution, heat up to 65°C, react for 30min, after cooling to room temperature rapidly, filter, wash until the filtrate is neutral. Then, add 800g of water to the filter cake to make a slurry, add 40g of NH ₄ Cl, heat up to 75°C, exchange treatment for 1 hour until the Na ₂ O content is less than 0.2% by weight, filter and wash to obtain a molecular sieve filter cake; take 50g of the above molecular sieve (Dry basis) Add water to prepare molecular sieve slurry with solid content of 10% by weight, slowly add 733g of fluosilicic acid (3% by mass) under stirring, and add time for 30min; heat up to 65°C and stir at constant temperature for 1h, filter and wash with water until the filtrate is neutral ; add water to the filter cake and beat to obtain a molecular sieve slurry with a solid content of 40% by weight, add 0.75gH ₃ PO ₄ (concentration 85% by weight) and 3.3gZn(NO ₃ ) ₂ 6H ₂ O, mix evenly and soak, dry, 550 ℃ roasting treatment for 2 hours. The molecular sieve DA8 was obtained, and the physical and chemical properties, micro-reaction evaluation gasoline yield and octane number data are listed in Table 1.

Comparative example 9

Filter the crystallized ZSM-5 molecular sieve (produced by Catalyst Jianchang Branch, synthesized by amine method, n(SiO ₂ )/n(Al ₂ O ₃ )=310) and wash with water until the Na ₂ O content is low At 3.0% by weight, filter, dry, and burn off the template agent in air at 550 ° C for 2 hours; take 100 g (dry basis) of the above-mentioned molecular sieve and add it to 1500 g of NaOH aqueous solution (solution concentration 2.4%), stir and heat up to 65 ° C, After reacting for 40 minutes, cool to room temperature, filter, and rinse until the filtrate is neutral to obtain a filter cake; then take 50 g (dry basis) of the above-mentioned molecular sieve and add water to prepare a molecular sieve slurry with a solid content of 10% by weight, and add 220 g of hydrochloric acid (mass fraction 10%); heat up to 65°C and stir for 1 hour, filter and wash until the filtrate is neutral; add 1500g water to the filter cake for beating, add 80g NH ₄ Cl and heat up to 65°C for exchange and washing for 40min, filter, and rinse until the filtrate is neutral; Add water and beat the cake to obtain a molecular sieve slurry with a solid content of 40% by weight, add 1.0gH ₃ PO ₄ (concentration 85% by weight) and 3.3gZn(NO ₃ ) ₂ 6H ₂ O, mix evenly, impregnate, dry, and roast at 550°C 2 hours. The molecular sieve DA9 was obtained, and the physical and chemical properties, micro-reaction evaluation gasoline yield and octane number data are listed in Table 1.

Comparative example 10

Filter the crystallized ZSM-5 molecular sieve (produced by Catalyst Jianchang Branch, synthesized by amine method, n(SiO ₂ )/n(Al ₂ O ₃ )=72) and wash with water until the Na ₂ O content is low At 3.0% by weight, filter, dry, and burn off the template agent at 550°C in the air for 2 hours; take 100g (dry basis) of the above-mentioned molecular sieve and add water to prepare a molecular sieve slurry with a solid content of 10% by weight, and add 670g of fluorosilicic acid during stirring (mass fraction 3%), adding time 30min; heat up to 65°C and stir at constant temperature for 1h, filter and wash with water until the filtrate is neutral; add the molecular sieve obtained above into 1000g of 2.0% NaOH solution, heat up to 65°C, react for 30min, and then rapidly cool After reaching room temperature, filter and wash until the filtrate is neutral. Then exchange and wash with NH ₄ Cl solution until the Na ₂ O content is lower than 0.1% by weight, filter and wash to obtain a molecular sieve filter cake; add water to the molecular sieve filter cake (50 g on a dry basis) and beat to obtain a molecular sieve slurry with a solid content of 40% by weight, Add 1.2g of H ₃ PO ₄ (concentration: 85% by weight) and 3.3g of Zn(NO ₃ ) ₂ ·6H ₂ O, uniformly mix and impregnate, dry, and bake at 550°C for 2 hours. The molecular sieve DA10 was obtained, and the physical and chemical properties, micro-reaction evaluation gasoline yield and octane number data are listed in Table 1.

Comparative example 11

The crystallized ZSM-5 molecular sieve (produced by Catalyst Qilu Branch, synthesized by amine-free method, n(SiO ₂ )/n(Al ₂ O ₃ )=27) was filtered to remove the mother liquor, washed with water until the Na ₂ O content was lower than 3.0 % by weight, filtered to obtain a filter cake; take 100g (dry basis) of the above molecular sieve and add water to prepare a molecular sieve slurry with a solid content of 10 wt%. Add in parallel flow, the addition time is 30min, and finally add 480g hydrochloric acid (mass fraction 10%); heat up to 85°C and stir at a constant temperature for 6h, filter and wash until the filtrate is neutral; add 1000g of 2.2% NaOH solution, heat up to 60°C, and react for 45min After cooling to room temperature rapidly, filter and wash until the filtrate is neutral. Then exchange and wash with NH ₄ Cl solution until the Na ₂ O content is lower than 0.1% by weight, and filter to obtain a molecular sieve filter cake; take 50 g (dry basis) of the above molecular sieve filter cake and beat with water to obtain a molecular sieve slurry with a solid content of 40% by weight, add 1.2g of H ₃ PO ₄ (concentration: 85% by weight) and 3.3g of Zn(NO ₃ ) ₂ ·6H ₂ O were uniformly mixed and impregnated, dried and calcined at 550°C for 2 hours. The molecular sieve DA11 was obtained, and the physical and chemical properties, micro-reaction evaluation gasoline yield and octane number data are listed in Table 1.

Comparative example 12

The crystallized ZSM-5 molecular sieve (produced by Catalyst Jianchang Branch, synthesized by amine method, n(SiO ₂ )/n(Al ₂ O ₃ )=210) was filtered to remove the mother liquor, and then exchanged and washed with NH ₄ Cl to Na The content of ₂ O is less than 0.2% by weight, dry it, and burn off the template agent at 550°C in the air for 2 hours; take 100g (dry basis) of the above-mentioned molecular sieve and beat it with water to obtain a molecular sieve slurry with a solid content of 40% by weight, and add _1.6gH3 PO ₄ (concentration 85%) and 6.6g Zn(NO ₃ ) ₂ ·6H ₂ O were impregnated and dried; the obtained sample was calcined at 550°C for 2 hours to obtain molecular sieve DA12. The physical and chemical properties, micro-reaction evaluation gasoline yield and octane number data are listed in Table 1.

Comparative example 13

The crystallized ZSM-5 molecular sieve (produced by Catalyst Qilu Branch, synthesized by amine-free method, n(SiO ₂ )/n(Al ₂ O ₃ )=27) was exchanged and washed with NH ₄ Cl solution until the Na ₂ O content was low Filter cake at 0.2% by weight; take 100g (dry basis) of the above-mentioned molecular sieve and add water to be mixed with a molecular sieve slurry with a solid content of 10% by weight, add 40g of citric acid during stirring, then mix 100g of sulfuric acid (10% by mass fraction) and 500g of fluorine Silicic acid (mass fraction 3%) was added concurrently, and the addition time was 30 minutes; the temperature was raised to 45° C. and stirred for 1 hour, filtered and washed until the filtrate was neutral; the filter cake was beaten with water to obtain a molecular sieve slurry with a solid content of 40% by weight, and 2.0 g H ₃ PO ₄ (concentration: 85% by weight) and 5.0 g of Ga ₂ (SO ₄ ) ₃ ·16H ₂ O were uniformly mixed and impregnated, dried and calcined at 550° C. for 2 hours. The molecular sieve DA13 was obtained, and the physical and chemical properties, micro-reaction evaluation gasoline yield and octane number data are listed in Table 1.

Example 2

The crystallized ZSM-5 molecular sieve (produced by Catalyst Qilu Branch, synthesized by amine-free method, n(SiO ₂ )/n(Al ₂ O ₃ )=27) was filtered to remove the mother liquor, washed with water until the Na ₂ O content was lower than 3.0 % by weight, filtered to obtain a filter cake; get the above-mentioned molecular sieve 100g (dry basis) and add in 1500g 2.4% NaOH solution, heat up to 60°C, after reacting for 45min, after rapidly cooling to room temperature, filter and wash until the filtrate is neutral. Then, add 800g of water to the filter cake to make a slurry, add 40g of NH ₄ Cl, heat up to 75°C, exchange treatment for 1 hour until the Na ₂ O content is less than 0.2% by weight, filter and wash to obtain a molecular sieve filter cake; take 50g of the above molecular sieve (dry basis) add water to prepare molecular sieve slurry with a solid content of 10% by weight, add 22g of citric acid during stirring, then add 55g of sulfuric acid (10% by mass fraction) and 280g of fluosilicic acid (3% by mass fraction) in parallel, and add the time 30min; heat up to 45°C and stir for 1h, filter and wash until the filtrate is neutral; add water to the filter cake and beat to obtain a molecular sieve slurry with a solid content of 45% by weight; mix 1.0gH ₃ PO ₄ (concentration 85% by weight) and 2.5g Ga ₂ (SO ₄ ) ₃ ·16H ₂ O was dissolved in 10g of water, adjusted to pH=4 with ammonia water, then added to the molecular sieve slurry, mixed evenly, dried, and calcined at 550°C for 2 hours under 100% steam atmosphere. Molecular sieve B was obtained, and the physical and chemical properties, micro-reaction evaluation gasoline yield and octane number data are listed in Table 1.

Comparative example 14

The crystallized ZSM-5 molecular sieve (produced by Catalyst Qilu Branch, synthesized by amine-free method, n(SiO ₂ )/n(Al ₂ O ₃ )=27) was filtered to remove the mother liquor, washed with water until the Na ₂ O content was lower than 3.0 % by weight, filtered to obtain a filter cake; get the above-mentioned molecular sieve 100g (dry basis) and add in 1500g 2.4% NaOH solution, heat up to 60°C, after reacting for 45min, after rapidly cooling to room temperature, filter and wash until the filtrate is neutral. Then, add 800g of water to the filter cake to make a slurry, add 40g of NH ₄ Cl, heat up to 75°C, exchange treatment for 1 hour until the Na ₂ O content is less than 0.2% by weight, filter and wash to obtain a molecular sieve filter cake; take 50g of the above molecular sieve (dry basis) add water to prepare molecular sieve slurry with a solid content of 10% by weight, add 22g of citric acid during stirring, then add 55g of sulfuric acid (10% by mass fraction) and 280g of fluosilicic acid (3% by mass fraction) in parallel, and add the time 30min; heat up to 45°C and stir for 1h, filter and wash until the filtrate is neutral; add water to the filter cake and beat to obtain a molecular sieve slurry with a solid content of 40% by weight, add 1.0gH ₃ PO ₄ (concentration: 85% by weight), and mix evenly for impregnation, Dry and bake at 550°C for 2 hours. The molecular sieve DB1 was obtained, and the physical and chemical properties, micro-reaction evaluation gasoline yield and octane number data are listed in Table 1.

As can be seen from the data in Table 1, for the ZSM-5 molecular sieve after alkali treatment desiliconization, adopt single organic acid oxalic acid dealumination (DA2), adopt single inorganic hydrochloric acid dealumination (DA3) and adopt organic acid oxalic acid and inorganic Both hydrochloric acid and acid complex (DA5) cannot effectively remove Al from molecular sieves, and the silicon-aluminum ratio does not increase significantly, but only after using fluosilicic acid can a better dealumination effect be obtained. When fluorosilicate dealumination (DA4) is used alone, ZSM-5 molecular sieve with high silicon-aluminum ratio can be obtained, but the mesopores are relatively small, the proportion of strong acid in the total acid is low, and the ratio of B acid/L acid is low . Fluorosilicic acid composite organic acid oxalate dealumination (DA6) also cannot obtain a higher mesopore ratio and better acid distribution. Fluorosilicic acid composite inorganic hydrochloric acid dealumination (DA7), although the mesopore volume is increased, but the proportion of strong acid in the total acid and the ratio of B acid/L acid are not as high as the molecular sieve provided by the present disclosure. Simply relying on increasing the amount of fluorosilicic acid to treat the desiliconized molecular sieve can also obtain a higher silicon-aluminum ratio ZSM-5 molecular sieve (DA8), but the crystallinity of the molecular sieve is seriously lost, and the pore distribution and acidity distribution are poor. The ZSM-5 molecular sieve with the higher silicon-aluminum ratio synthesized is processed by acid-base treatment technology, although the ZSM-5 molecular sieve (DA9) containing mesoporous silicon-alumina ratio range in line with the present disclosure can be obtained, but the Al distribution of the molecular sieve is relatively low. Poor, less strong acid, low ratio of B acid/L acid. The molecular sieves (DA10 and DA11) obtained by increasing the silicon-aluminum ratio of the ZSM-5 molecular sieve by using a single fluorosilicic acid or a compound organic and inorganic acid (DA10 and DA11) have a low proportion of mesopores and relatively high Al on the outer surface of the molecular sieve. Many, poor acid distribution. However, the directly synthesized molecular sieve with high silicon-aluminum ratio (DA12) and the molecular sieve (DA13) obtained by complex acid dealumination of silicon do not have abundant secondary pores. In this disclosure, the molecular sieve is desiliconized first, and then the composite acid system is used. Under the synergistic effect of the three acids, the silicon-aluminum ratio of the molecular sieve can be effectively increased under the premise of ensuring the integrity of the molecular sieve crystal structure and mesoporous channel structure. Adjust aluminum distribution and improve acid distribution. In the molecular sieve prepared by the present disclosure, the loaded metals are enriched on the surface of the molecular sieve. From the data of gasoline yield and octane number, it can be seen that the molecular sieve prepared by the present disclosure can more effectively adjust the composition of gasoline while increasing the gasoline yield. , reduce the content of olefins and increase the content of aromatics, and the octane number of gasoline is also increased.

Table 1

Claims (16)

1. A phosphorus-containing and metal-loaded MFI molecular sieve, the molecular sieve's n(SiO ₂ )/n(Al ₂ O ₃ ) is greater than 100; in terms of P ₂ O ₅ and based on the dry weight of the molecular sieve, The phosphorus content of the molecular sieve is 0.1-5% by weight; calculated based on the oxide of the loaded metal and based on the dry weight of the molecular sieve, the loaded metal content of the molecular sieve is 0.5-5% by weight; the Al distribution of the molecular sieve is The parameter D(Al) satisfies: 0.6≤D(Al)≤0.85, wherein, D(Al)=Al(S)/Al(C), and Al(S) represents the molecular sieve grain size measured by TEM-EDS method The aluminum content in any area greater than 100 square nanometers within the distance H from the edge of the surface, Al(C) means the area of any area greater than 100 square nanometers within the distance H from the geometric center of the crystal plane of the molecular sieve crystal grain measured by the TEM-EDS method Aluminum content, wherein said H is 10% of the distance from a certain point on the edge of the crystal plane to the geometric center of the crystal plane; the loaded metal distribution parameter D(M) of the molecular sieve satisfies: 2≤D(M)≤10, Wherein, D(M)=M(S)/M(C), M(S) represents the loaded metal of any area greater than 100 square nanometers within the distance H from the edge of the molecular sieve grain measured by the TEM-EDS method Content, M (C) represents the loaded metal content in any area greater than 100 square nanometers in the distance H from the geometric center of the crystal plane of the molecular sieve grain measured by the TEM-EDS method; the mesopore volume of the molecular sieve accounts for the total pores The proportion of the volume is 40-80% by volume, and the proportion of the mesopore volume with a pore diameter of 2 nm to 20 nm to the total mesoporous volume is greater than 90% by volume; the ratio of the strong acid amount of the molecular sieve to the total acid amount is 60-80% %, the ratio of the amount of B acid to the amount of L acid is 15-80. 2. The molecular sieve with MFI structure according to claim 1, wherein the n(SiO ₂ )/n(Al ₂ O ₃ ) of the molecular sieve is greater than 120; in terms of P ₂ O ₅ and based on the dry weight of the molecular sieve , the phosphorus content of the molecular sieve is 0.2-4% by weight; based on the oxide of the loaded metal and based on the dry weight of the molecular sieve, the loaded metal content of the molecular sieve is 0.5-3% by weight; the Al of the molecular sieve The distribution parameter D(Al) satisfies: 0.65≤D(Al)≤0.8; the loaded metal distribution parameter D(M) of the molecular sieve satisfies: 3≤D(M)≤6; the mesopore volume of the molecular sieve accounts for the total pores The proportion of the volume is 50-70% by volume, and the proportion of the mesopore volume with a pore diameter of 2 nm to 20 nm to the total mesoporous volume is greater than 92% by volume; the ratio of the strong acid amount of the molecular sieve to the total acid amount is 65-75% %, the ratio of B acid to L acid is 20-50. 3. The molecular sieve with MFI structure according to claim 1, wherein the supported metal is zinc and/or gallium. 4. The molecular sieve with MFI structure according to claim 1, wherein the mesopore is a molecular sieve channel with an aperture greater than 2 nanometers and less than 100 nanometers; the ratio of the strong acid content of the molecular sieve to the total acid content adopts the NH ₃ -TPD method For measurement, the acid center of the strong acid is the acid center corresponding to the NH ₃ desorption temperature greater than 300°C; the ratio of the acid amount of the B acid to the acid amount of the L acid is measured by a pyridine adsorption infrared acid method. 5. a preparation method of phosphorus-containing and metal-loaded MFI molecular sieves according to any one of claims 1-4, the preparation method comprising: a. After filtering and washing the MFI structure molecular sieve slurry obtained by crystallization, water-washed molecular sieves are obtained; wherein, the sodium content of the water-washed molecular sieves is less than 3% by weight, calculated as sodium oxide and based on the total dry weight of the water-washed molecular sieves; b. Desiliconizing the water-washed molecular sieve obtained in step a in an alkaline solution, and filtering and washing to obtain a desiliconized molecular sieve; c. Perform ammonium exchange treatment on the desiliconized molecular sieve obtained in step b to obtain ammonium exchanged molecular sieve; wherein, based on the total dry basis weight of ammonium oxide and ammonium exchanged molecular sieve, the sodium content of the ammonium exchanged molecular sieve is less than 0.2 wt. %; d, the ammonium-exchanged molecular sieve obtained in step c is dealuminated in a complex acid dealumination agent solution composed of fluosilicic acid, organic acid and inorganic acid, and after filtering and washing, the dealuminated molecular sieve is obtained; e. After the dealuminated molecular sieve obtained in step d is subjected to phosphorus modification treatment and metal loading treatment, a modified molecular sieve is obtained; f. The modified molecular sieve obtained in step e is hydrothermally calcined to obtain the phosphorus-containing and metal-loaded molecular sieve with MFI structure. 6. The preparation method according to claim 5, wherein the alkaline solution in step b is sodium hydroxide solution and/or potassium hydroxide solution. 7. The preparation method according to claim 5, wherein, the conditions of the desiliconization treatment described in step b include: the weight ratio of the molecular sieve on a dry basis to the alkali in the alkali solution is 1: (0.1-1) ; The temperature of the desiliconization treatment is 25-100°C, and the time is 15 minutes-8 hours. 8. The preparation method according to claim 5, wherein, the conditions of the desiliconization treatment described in step b include: the weight ratio of the molecular sieve on a dry basis to the alkali in the alkali solution is 1: (0.15-0.4) . 9. The preparation method according to claim 5, wherein, the step of dealumination described in step d further comprises: first mixing an organic acid with the ammonium-exchanged molecular sieve, then mixing fluorosilicic acid and inorganic acid with the Ammonium exchanged molecular sieves were mixed. 10. The preparation method according to claim 5, wherein the organic acid in step d is at least one selected from ethylenediaminetetraacetic acid, oxalic acid, citric acid and sulfosalicylic acid, and the inorganic acid It is at least one selected from hydrochloric acid, sulfuric acid and nitric acid. 11. The preparation method according to claim 5, wherein the organic acid described in step d is oxalic acid, and the inorganic acid is hydrochloric acid. 12. The preparation method according to claim 5, wherein the conditions of the dealumination treatment described in step d include: the weight ratio of molecular sieve, fluosilicic acid, organic acid and inorganic acid in dry basis weight is 1: (0.02-0.5):(0.05-0.5):(0.05-0.5); the treatment temperature is 25-100°C, and the treatment time is 0.5-6 hours. 13. The preparation method according to claim 5, wherein the conditions of the dealumination treatment described in step d include: the weight ratio of molecular sieve, fluosilicic acid, organic acid and inorganic acid in dry basis weight is 1: (0.05-0.3):(0.1-0.3):(0.1-0.3). 14. The preparation method according to claim 5, wherein, the phosphorus modification treatment described in step e comprises: at least one phosphorus-containing compound selected from phosphoric acid, ammonium hydrogen phosphate, ammonium dihydrogen phosphate and ammonium phosphate Molecular sieves are impregnated and/or ion exchanged. 15. The preparation method according to claim 5, wherein, the loading treatment of the loaded metal in step e comprises: dissolving a soluble salt containing at least one loaded metal selected from zinc and gallium in deionized water, using ammonia Adjust the pH value to precipitate the loaded metal in the form of hydroxide, and then mix the obtained precipitate with molecular sieves evenly. 16. The preparation method according to claim 5, wherein the conditions of the hydrothermal calcination treatment in step f include: the atmosphere of the calcination treatment is a water vapor atmosphere; the calcination temperature is 400-800°C, and the calcination time is 0.5-8 Hour.