Mesoporous BEA molecular sieve and preparation method and application thereof

Abstract

The invention discloses a mesoporous BEA molecular sieve and a preparation method and application thereof. The average pore diameter R of the mesoporous BEA molecular sieve is 2-8 nm, the specific surface area S mesopores of mesopores is 150-500 m < 2 > / g, the ratio of S mesopores to S micropores is 1.5-7, and the Na content is lower than 1.0%. According to the NH3-TPD result, the ratio of weak acid to medium-strong acid in the mesoporous BEA molecular sieve is (0.8-2): 1. The mesoporous BEA molecular sieve is relatively high in mesoporous specific surface area and relatively large in average pore size, is beneficial to diffusion of reactants and products in an aromatic hydrocarbon deolefination reaction, and can obviously prolong the service life of a catalyst and slow down inactivation of the catalyst; the Na content of the molecular sieve is low, post-treatment such as acid exchange or ammonium exchange is not needed, and the molecular sieve can be directly used.

Description

Technical Field

[0001] The invention belongs to the field of molecular sieves, and in particular relates to a mesoporous BEA molecular sieve and a preparation method and application thereof. Background Art

[0002] Molecular sieves have regular pore structures, good thermal stability and strong acidity, and are widely used in important catalytic reactions such as hydrocracking, catalytic cracking and isomerization. Due to the unique structure of zeolite molecular sieves and their excellent performance in catalysis, the synthesis and application research of zeolite molecular sieve materials has attracted much attention and is becoming increasingly widespread.

[0003] Aromatics is the basic raw material of the petrochemical industry, and it mainly comes from aromatics complexes. Aromatic products after catalytic reforming reactions contain a certain amount of olefin impurities. Olefins are active in nature and are not only easy to polymerize to form colloids, but may also react with other components to generate non-ideal components, thus having a significant impact on the quality of aromatic products.

[0004] On the other hand, some petrochemical processes, such as xylene adsorption separation, are particularly sensitive to olefins. Even if the content of olefin impurities is only a few parts per million, it will have a very adverse effect on the process. In order to obtain qualified chemical raw materials and ensure the smooth progress of subsequent processes, after the reforming, aromatics extraction, isomerization, and toluene disproportionation processes, there are refining processes to remove trace olefin impurities.

[0005] Sinopec and CNOOC have developed molecular sieve refining catalysts with USY molecular sieve as the active center. Sinopec Shanghai Petrochemical Research Institute has successively developed two generations of reforming oil non-hydrogenation catalytic deolefination catalysts, DOT-100 and DOT-200. -1 Under the conditions of reaction pressure of 1.1MPa and reaction temperature of 157-185℃, the one-way life of DOT-100 is 7-8 times that of clay, and the total life is more than 30 times that of clay. DOT-200 catalyst has an average bromine index of 800mgBr / 100g and a weight space velocity of 1.7-1.8h -1 Under certain conditions, the life of a single cycle is equivalent to 15 times that of clay, and the total life can reach more than 50 times that of clay. CNOOC Tianjin Chemical Research and Design Institute has developed the TCDTO-01 reforming oil catalytic degassing system catalyst. It is reported that the catalyst can be regenerated 3-4 times, and its total life can reach 1.5-2 years.

[0006] At present, Y molecular sieve is commonly used as deolefination catalyst. Due to the small diameter of the pores of Y molecular sieve, the macromolecules generated during the olefin alkylation process cannot escape quickly in its pores and are easily blocked at the pores and deactivated.

[0007] BEA molecular sieve has three-dimensional 12MR channels, but conventional BEA still suffers from a fast deactivation rate when used in aromatic bromine index reduction reactions. Summary of the invention

[0008] In order to overcome the problems existing in the prior art, the present invention provides a mesoporous BEA molecular sieve and a preparation method and application thereof, wherein the mesoporous BEA molecular sieve has a high mesopore specific surface area (accounting for a large proportion of the specific surface area), the mesoporous BEA molecular sieve has a large average pore size, and the mesoporous BEA molecular sieve is beneficial to the diffusion of reactants and products in the aromatic deolefination reaction, which can significantly extend the catalyst life and slow down the catalyst deactivation; the mesoporous BEA molecular sieve has a low Na content and can be used directly without post-treatment such as acid exchange or ammonium exchange; the mesoporous BEA molecular sieve has a suitable ratio of weak acid to medium-strong acid, which is beneficial to the aromatic deolefination reaction, inhibits side reactions, and further extends the catalyst life.

[0009] The present invention provides a mesoporous BEA molecular sieve, wherein the average pore size R of the mesoporous BEA molecular sieve is 2 to 8 nm, and the specific surface area S of the mesopores is 介孔 150~500m 2 / g, the ratio of the specific surface area of ​​mesopores to micropores in the mesoporous BEA molecular sieve is S 介孔 / S 微孔 The content of Na in the mesoporous BEA molecular sieve is less than 1.0%.

[0010] In the first aspect of the present invention, the average pore size R of the mesoporous BEA molecular sieve is 3 to 6 nm, and the specific surface area S of the mesopores is 介孔 250~450m 2 / g,S 介孔 / S 微孔 The content of Na in the mesoporous BEA molecular sieve is less than 0.5%.

[0011] In the first aspect of the present invention, based on NH3-TPD results, the ratio of weak acid to medium strong acid in the mesoporous BEA molecular sieve is (0.8-2):1, preferably (1.02-1.5):1, for example, 0.8:1, 1:1, 1.2:1, 1.4:1, 1.6:1, 1.8:1 or 2:1.

[0012] In the present invention, the temperature range of the weak acid is 100-300°C, and the temperature range of the medium-strong acid is 300-500°C.

[0013] The second aspect of the present invention is to provide a method for preparing a mesoporous BEA molecular sieve, preferably for preparing the mesoporous BEA molecular sieve, the preparation method comprising: (1) mixing an alkali, an aluminum source, a silicon source, a template, and water to obtain a dispersion; (2) performing crystallization and filtering separation to obtain a filtrate and a solid intermediate; (3) placing the solid intermediate in a steam environment for steam treatment, and then drying and calcining to obtain the mesoporous BEA molecular sieve.

[0014] In the second aspect of the present invention, the base is selected from at least one of sodium hydroxide, potassium hydroxide, ammonia water, urea, methylamine, ethylamine, and ethylenediamine; and / or the aluminum source is selected from at least one of sodium aluminate, aluminum sulfate, aluminum nitrate, aluminum sol, and aluminum isopropoxide; and / or the silicon source is selected from at least one of sodium silicate, silica sol, white carbon black, water glass, and tetraethyl silicate; and / or the template is selected from at least one of tetraethylammonium hydroxide and tetraethylammonium bromide.

[0015] In the second aspect of the present invention, the molar ratio of the base to the aluminum source is (0.01-1):1, preferably (0.1-0.6):1; and / or the molar ratio of the template to the aluminum source is (0.1-10):1, preferably (2-5):1; and / or the molar ratio of the silicon source to the aluminum source is (2-20):1, preferably (8-15):1; and / or the molar ratio of the water to the aluminum source is (50-500):1, preferably (100-300):1; wherein the molar amounts of the base, the template and the water are respectively measured by the molar amounts of their molecules, the molar amount of the aluminum source is measured by the molar amount of Al2O3, and the molar amount of the silicon source is measured by the molar amount of SiO2.

[0016] In the second aspect of the present invention, in step (2), the crystallization conditions include: temperature 90-120° C., time 3-10 days; preferably, the crystallization conditions include: temperature 100-120° C., time 6-10 days.

[0017] In the second aspect of the present invention, the steam environment in step (3) is a water vapor environment or the steam environment of the filtrate in step (2), preferably the steam environment of the filtrate in step (2); more preferably, the treatment is carried out in a steam environment at 100-160°C for 2-10 hours.

[0018] The third aspect of the present invention is to provide a catalyst comprising a mesoporous BEA molecular sieve and a binder, wherein the mesoporous BEA molecular sieve is the mesoporous BEA molecular sieve described in the first aspect or the mesoporous BEA molecular sieve obtained by the preparation method described in the second aspect.

[0019] In the third aspect of the present invention, the binder is selected from at least one of aluminum oxide, silicon oxide, zirconium oxide and titanium oxide.

[0020] In the third aspect of the present invention, based on 100 wt % of the catalyst, the mesoporous BEA molecular sieve accounts for 50-95 wt % and the binder accounts for 5-50 wt %.

[0021] The fourth aspect of the present invention is to provide the use of the mesoporous BEA molecular sieve described in the first aspect of the present invention, or the mesoporous BEA molecular sieve obtained by the preparation method described in the second aspect of the present invention, or the catalyst described in the third aspect of the present invention in the deolefination of aromatics.

[0022] The fifth aspect of the present invention is to provide a method for deolefination of aromatic hydrocarbons, comprising: contact reaction of raw aromatic hydrocarbons with the mesoporous BEA molecular sieve described in the first aspect of the present invention, or the mesoporous BEA molecular sieve obtained by the preparation method described in the second aspect of the present invention, or the catalyst described in the third aspect of the present invention.

[0023] In the fifth aspect of the present invention, the reaction conditions include: temperature of 150-270°C, pressure of 0.6MPa-3.0MPa, weight space velocity of 1-20h -1 .

[0024] The endpoints and any values ​​of the scope disclosed in the present invention are not limited to the precise scope or value, and these scopes or values ​​should be understood to include values ​​close to these scopes or values. For numerical ranges, the endpoint values ​​of each scope, the endpoint values ​​of each scope and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be regarded as specifically disclosed in this article. Hereinafter, in principle, each technical solution can be combined with each other to obtain a new technical solution, which should also be regarded as specifically disclosed in this article.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) A BEA molecular sieve with high mesoporous specific surface area, large average pore size, low Na content and suitable acidity distribution was synthesized by a crystallization-steam treatment method;

[0027] (2) The method of the present invention makes the mesoporous distribution in the mesoporous BEA molecular sieve more uniform and the mesoporous specific surface area higher; at the same time, the steam treatment also reduces the Na content of the molecular sieve, so that there is no need for post-treatment such as acid exchange or ammonium exchange, and the molecular sieve can be used directly;

[0028] (3) When this mesoporous BEA molecular sieve is used in the deolefination reaction of aromatic hydrocarbons, it has the advantage of long service life. DETAILED DESCRIPTION

[0029] The following detailed description of the present invention will make the features and advantages of the present invention more clear and explicit.

[0030] One of the purposes of the present invention is to provide a mesoporous BEA molecular sieve, wherein the average pore size R of the mesoporous BEA molecular sieve is 2 to 8 nm, and the specific surface area S of the mesopores is 介孔 150~500m 2 / g, the ratio of the specific surface area of ​​mesopores to micropores in the mesoporous BEA molecular sieve is S 介孔 / S 微孔 The content of Na in the mesoporous BEA molecular sieve is less than 1.0%.

[0031] For example, the average pore size R of the mesoporous BEA molecular sieve is 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm or 8 nm, and the specific surface area S of the mesopores is 介孔 150m 2 / g, 200m 2 / g, 250m 2 / g、300m 2 / g, 350m 2 / g, 400m 2 / g, 450m 2 / g or 500m 2 / g,S 介孔 / S 微孔 is 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5 or 7, and the Na content in the mesoporous BEA molecular sieve is 0, 0.2%, 0.4%, 0.6%, 0.8% or 1.0%.

[0032] In a preferred embodiment, the average pore size R of the mesoporous BEA molecular sieve is 3 to 6 nm, and the specific surface area S of the mesopores is 介孔 250~450m 2 / g, the ratio of the specific surface area of ​​mesopores to micropores in the mesoporous BEA molecular sieve is S 介孔 / S 微孔 The content of Na in the mesoporous BEA molecular sieve is less than 0.5%.

[0033] In a preferred embodiment, based on the NH3-TPD results, the ratio of weak acid to medium strong acid in the mesoporous BEA molecular sieve is (0.8-2):1, preferably (1.02-1.5):1, for example, 0.8:1, 1:1, 1.2:1, 1.4:1, 1.6:1, 1.8:1 or 2:1.

[0034] Wherein, the ratio of the weak acid to the medium-strong acid is the ratio of the weak acid peak area to the medium-strong acid peak area in the NH3-TPD result. In the present invention, the temperature range of the weak acid is 100-300°C, and the temperature range of the medium-strong acid is 300-500°C.

[0035] The second object of the present invention is to provide a method for preparing a mesoporous BEA molecular sieve, preferably for preparing the mesoporous BEA molecular sieve described in one of the objects of the present invention, the preparation method comprising: (1) mixing an alkali, an aluminum source, a silicon source, a template, and water to obtain a dispersion; (2) performing crystallization and filtering separation to obtain a filtrate and a solid intermediate; (3) placing the solid intermediate in a steam environment for steam treatment, and then drying and calcining to obtain the mesoporous BEA molecular sieve.

[0036] In a preferred embodiment, step (1) comprises: mixing alkali, aluminum source and water to obtain dispersion A, mixing silicon source, template and water to obtain dispersion B, and then mixing the dispersion A and the dispersion B to obtain the dispersion.

[0037] The dispersion liquid, the dispersion liquid A, and the dispersion liquid B of the present invention are preferably solutions.

[0038] In a further preferred embodiment, dispersion B is added to dispersion A to obtain the dispersion.

[0039] In a further preferred embodiment, dispersion B is added to dispersion A by dropwise addition.

[0040] In a preferred embodiment, the base is selected from at least one of sodium hydroxide, potassium hydroxide, aqueous ammonia, urea, methylamine, ethylamine, and ethylenediamine, preferably sodium hydroxide.

[0041] In a preferred embodiment, the aluminum source is selected from at least one of sodium aluminate, aluminum sulfate, aluminum nitrate, aluminum sol, and aluminum isopropoxide.

[0042] In a preferred embodiment, the silicon source is selected from at least one of sodium silicate, silica sol, white carbon black, water glass, and tetraethyl silicate.

[0043] In a preferred embodiment, the template is selected from at least one of tetraethylammonium hydroxide and tetraethylammonium bromide, preferably tetraethylammonium hydroxide.

[0044] In a preferred embodiment, the molar ratio of the base to the aluminum source is (0.01-1):1, and / or the molar ratio of the template to the aluminum source is (0.1-10):1, and / or the molar ratio of the silicon source to the aluminum source is (2-20):1, and / or the molar ratio of the water to the aluminum source is (50-500):1, wherein the molar amounts of the base, the template and the water are respectively measured by the molar amounts of their molecules, the molar amount of the aluminum source is measured by the molar amount of Al2O3, and the molar amount of the silicon source is measured by the molar amount of SiO2.

[0045] In a further preferred embodiment, the molar ratio of the base to the aluminum source is (0.1-0.6):1, and / or the molar ratio of the template to the aluminum source is (2-5):1, and / or the molar ratio of the silicon source to the aluminum source is (8-15):1, and / or the molar ratio of the water to the aluminum source is (100-300):1, wherein the molar amounts of the base, the template and the water are respectively measured by the molar amounts of their molecules, the molar amount of the aluminum source is measured by the molar amount of Al2O3, and the molar amount of the silicon source is measured by the molar amount of SiO2.

[0046] For example, the molar ratio of the base to the aluminum source is 0.1:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1 or 0.6:1, and / or the molar ratio of the template to the aluminum source is 2:1, 3:1, 4:1 or 5:1, and / or the molar ratio of the silicon source to the aluminum source is 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1 or 15:1, and / or the molar ratio of the water to the aluminum source is 100:1, 150:1, 200:1, 250:1 or 300:1, wherein the molar amounts of the base, the template and the water are respectively measured by the molar amounts of their molecules, the molar amount of the aluminum source is measured by the molar amount of Al2O3, and the molar amount of the silicon source is measured by the molar amount of SiO2.

[0047] In a preferred embodiment, in step (2), the crystallization conditions include: temperature of 90 to 120° C. and time of 3 to 10 days.

[0048] In a further preferred embodiment, in step (2), the crystallization conditions include: temperature of 100-120° C. and time of 6-10 days.

[0049] For example, in step (2), the crystallization conditions include: temperature of 90°C, 95°C, 100°C, 105°C, 110°C, 115°C or 120°C, and time of 3d, 4d, 5d, 6d, 7d, 8d, 9d or 10d.

[0050] In a preferred embodiment, the steam environment in step (3) is a water vapor environment or the steam environment of the filtrate in step (2), preferably the steam environment of the filtrate in step (2).

[0051] After a large number of experiments, the inventors found that if the solid intermediate is directly treated in boiling water, the effect is far inferior to that of steam treatment. The reason is that the appearance of mesopores in the BEA molecular sieve is formed by the dissolution of silicon and aluminum by the template inside the molecular sieve, and steam treatment accelerates this process; in a water vapor environment, the template inside the molecular sieve will slowly lose into the water, and the filtrate vapor contains both water and the template, and the template inside the molecular sieve will not be obviously lost. Therefore, it is preferred to use the steam environment of the filtrate; in a boiling water environment, the template loss rate is faster, resulting in insufficient number and uniformity of mesopores in the BEA molecular sieve.

[0052] In a further preferred embodiment, in step (3), the treatment is carried out in a steam environment at 100 to 160° C. for 2 to 10 hours.

[0053] For example, in step (3), the treatment is carried out in a steam environment at 100° C., 110° C., 120° C., 130° C., 140° C., 150° C. or 160° C. for 2 h, 4 h, 6 h, 8 h or 10 h.

[0054] In a further preferred embodiment, in step (3), the treatment is carried out in a steam environment at 100-120° C. for 3-6 hours.

[0055] In a preferred embodiment, in step (3), the drying temperature is 25°C to 180°C, preferably 50°C to 150°C, for example 25°C, 30°C, 50°C, 80°C, 100°C, 120°C, 150°C, 160°C or 180°C.

[0056] In a preferred embodiment, in step (3), the calcination conditions include: a temperature of 350 to 750° C., preferably 400 to 600° C.; and a calcination time of 0.5 to 10 h, preferably 2 to 8 h.

[0057] The third object of the present invention is to provide a catalyst comprising a mesoporous BEA molecular sieve and a binder, wherein the mesoporous BEA molecular sieve is the mesoporous BEA molecular sieve described in the first object of the present invention or the mesoporous BEA molecular sieve obtained by the preparation method described in the second object of the present invention.

[0058] In a preferred embodiment, the binder is selected from at least one of aluminum oxide, silicon oxide, zirconium oxide and titanium oxide.

[0059] In a preferred embodiment, based on 100 wt % of the catalyst, the mesoporous BEA molecular sieve accounts for 50-95 wt % and the binder accounts for 5-50 wt %.

[0060] For example, based on 100wt% of the catalyst, the mesoporous BEA molecular sieve accounts for 50wt%, 55wt%, 60wt%, 65wt%, 70wt%, 75wt%, 80wt%, 85wt%, 90wt% or 95wt%, and the binder accounts for 5wt%, 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt% or 50wt%.

[0061] In a further preferred embodiment, based on 100 wt % of the catalyst, the mesoporous BEA molecular sieve accounts for 60 to 80 wt %, and the binder accounts for 20 to 40 wt %.

[0062] The fourth object of the present invention is to provide the use of the mesoporous BEA molecular sieve described in the first object of the present invention, the mesoporous BEA molecular sieve obtained by the preparation method described in the second object of the present invention, or the catalyst described in the third object of the present invention in the deolefination of aromatics.

[0063] The reaction stability of the mesoporous BEA molecular sieve or the catalyst is 200 to 500 hours, preferably 250 to 400 hours, for example 200, 250, 300, 350, 400, 450 or 500 hours.

[0064] The fifth object of the present invention is to provide a method for deolefination of aromatic hydrocarbons, comprising: contact reaction of raw aromatic hydrocarbons with the mesoporous BEA molecular sieve described in the first object of the present invention, the mesoporous BEA molecular sieve obtained by the preparation method described in the second object of the present invention, or the catalyst described in the third object of the present invention.

[0065] In a preferred embodiment, the reaction conditions include: temperature of 150-270°C, pressure of 0.6 MPa-3.0 MPa, weight space velocity of 1-20 h -1 .

[0066] For example, the reaction conditions include: a temperature of 150°C, 160°C, 180°C, 200°C, 220°C, 240°C, 260°C or 270°C, a pressure of 0.6 MPa, 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa or 3.0 MPa, a weight space velocity of 1 h -1 , 2 o'clock -1 , 4 o'clock -1 , 6 o'clock -1 , 8:00 -1 , 10:00 -1 , 12 o'clock -1 , 14:00-1 , 16:00 -1 , 18:00 -1 or 20:00 -1 .

[0067] Example

[0068] The present invention is described in detail below in conjunction with specific embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by those skilled in the art based on the contents of the present invention still fall within the scope of protection of the present invention.

[0069] It should also be noted that the various specific technical features described in the following specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0070] In addition, the various embodiments of the present invention may be arbitrarily combined as long as they do not violate the concept of the present invention. The technical solutions thus formed belong to part of the original disclosure of this specification and also fall within the protection scope of the present invention.

[0071] The raw materials used in the examples and comparative examples, unless otherwise specified, are disclosed in the prior art, for example, they can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0072] [Example 1]

[0073] Sodium hydroxide, aluminum sulfate 18hydrate and water were stirred and dissolved at room temperature to obtain solution A, silica sol (SiO2 content 40wt%) and tetraethylammonium hydroxide (25wt%) were evenly dispersed in water to obtain solution B, solution B was added dropwise to solution A to obtain a gelling solution with a molar composition of NaOH:TEAOH:Al2O3:SiO2:H2O=0.6:2:1:12.5:250, crystallized at 100°C for 6 days, filtered to obtain a white solid and a filtrate, the white solid and deionized water were placed above and below the porous interlayer, respectively, treated in a crystallization kettle at 100°C water vapor environment for 5 hours, dried at 120°C for 12 hours, and calcined at 550°C in air atmosphere for 4 hours to obtain the mesoporous BEA molecular sieve MB-1. The average pore size R of MB-1 is 3.8nm, and the specific surface area S of the mesopores is 2.3nm. 介孔 283m 2 / g,S 介孔 / S 微孔 The pH value is 2.53, the Na content is 0.31%, and based on the NH3-TPD results, the ratio of weak acid to medium-strong acid is 1.04:1.

[0074] MB-1 and alumina are molded and calcined according to a formula of 70% and 30% on a dry basis to obtain the catalyst CMB-1 for removing olefins from aromatic materials.

[0075] 5g of the above catalyst was used to carry out a non-hydrogenation deolefination test of reformed oil in a fixed bed reactor. The raw material bromine index was 1300 mg Br / 100 g oil. The reaction temperature was 170°C, the reaction pressure was 2.0 MPa, and the space velocity was 8.0 h. -1 Taking the export bromine index of 200 mg Br / 100 g oil as the standard, the reaction stability reaches 276 hours.

[0076] [Example 2]

[0077] Sodium hydroxide, aluminum isopropoxide and water are stirred and dissolved at room temperature to obtain solution A, tetraethyl silicate and tetraethylammonium hydroxide (25wt%) are evenly dispersed in water to obtain solution B, solution B is added dropwise to solution A to obtain a gelling solution with a molar composition of NaOH:TEAOH:Al2O3:SiO2:H2O=0.28:4.1:1:12.5:210, crystallized at 110°C for 4 days, filtered to obtain a white solid and a filtrate, the white solid and deionized water are placed above and below the porous interlayer, respectively, treated in a crystallization kettle at 110°C in a water vapor environment for 4 hours, dried at 120°C for 12 hours, and calcined at 550°C in an air atmosphere for 4 hours to obtain the mesoporous BEA molecular sieve MB-2. The average pore size R of MB-2 is 4.2nm, and the specific surface area S of the mesopores is 2.3nm. 介孔 307m 2 / g,S 介孔 / S 微孔 The pH value is 3.62, the Na content is 0.17%, and based on the NH3-TPD results, the ratio of weak acid to medium-strong acid is 1.21:1.

[0078] MB-2 and alumina are molded and calcined according to a formula of 70% and 30% by weight on a dry basis to obtain the catalyst CMB-2 for deolefination of aromatic materials.

[0079] 5g of the above catalyst was used to carry out a non-hydrogenation deolefination test of reformed oil in a fixed bed reactor. The raw material bromine index was 1300 mg Br / 100 g oil. The reaction temperature was 170°C, the reaction pressure was 2.0 MPa, and the space velocity was 8.0 h. -1 , taking the export bromine index of 200 mg Br / 100 g oil as the standard, the reaction stability reaches 324 hours.

[0080] [Example 3]

[0081] Sodium hydroxide, aluminum sulfate 18hydrate and water were stirred and dissolved at room temperature to obtain solution A, tetraethyl silicate and tetraethylammonium hydroxide (25wt%) were evenly dispersed in water to obtain solution B, solution B was added dropwise to solution A to obtain a gelling solution with a molar composition of NaOH:TEAOH:Al2O3:SiO2:H2O=0.42:3:1:12.5:180, crystallized at 120°C for 3 days, filtered to obtain a white solid and a filtrate, the white solid and deionized water were placed above and below the porous interlayer, respectively, treated in a crystallization kettle at 110°C water vapor environment for 6 hours, dried at 120°C for 12 hours, and calcined at 550°C in air atmosphere for 4 hours to obtain the mesoporous BEA molecular sieve MB-3. The average pore size R of MB-3 is 4.7nm, and the specific surface area S of the mesopores is 2.3nm. 介孔 332m 2 / g,S 介孔 / S 微孔 The pH value is 4.14, the Na content is 0.22%, and based on the NH3-TPD results, the ratio of weak acid to medium-strong acid is 1.31:1.

[0082] MB-3 and alumina are molded and calcined according to a formula of 70% and 30% by weight on a dry basis to obtain the catalyst CMB-3 for removing olefins from aromatic materials.

[0083] 5g of the above catalyst was used to carry out a non-hydrogenation deolefination test of reformed oil in a fixed bed reactor. The raw material bromine index was 1300 mg Br / 100 g oil. The reaction temperature was 170°C, the reaction pressure was 2.0 MPa, and the space velocity was 8.0 h. -1 , taking the export bromine index of 200 mg Br / 100 g oil as the standard, the reaction stability reaches 360 hours.

[0084] [Example 4]

[0085] Sodium hydroxide, aluminum sulfate 18hydrate and water were stirred and dissolved at room temperature to obtain solution A, silica sol (SiO2 content 40wt%) and tetraethylammonium hydroxide (25wt%) were evenly dispersed in water to obtain solution B, solution B was added dropwise to solution A to obtain a gelling solution with a molar composition of NaOH:TEAOH:Al2O3:SiO2:H2O=0.6:2:1:12.5:250, crystallized at 100°C for 6 days, filtered to obtain a white solid and a filtrate, respectively placed above and below the porous interlayer, treated in a crystallization kettle at 100°C in a filtrate steam environment for 5 hours, dried at 120°C for 12 hours, and calcined at 550°C in an air atmosphere for 4 hours to obtain the mesoporous BEA molecular sieve MB-4. The average pore size R of MB-4 is 4.3nm, and the specific surface area S of the mesopores is 2.3nm. 介孔 311m 2 / g,S 介孔 / S 微孔The pH value is 4.90, the Na content is 0.27%, and based on the NH3-TPD results, the ratio of weak acid to medium-strong acid is 1.17:1.

[0086] MB-4 and alumina are molded and calcined according to a formula of 70% and 30% by weight on a dry basis to obtain the catalyst CMB-4 for removing olefins from aromatic materials.

[0087] 5g of the above catalyst was used to carry out a non-hydrogenation deolefination test of reformed oil in a fixed bed reactor. The raw material bromine index was 1300 mg Br / 100 g oil. The reaction temperature was 170°C, the reaction pressure was 2.0 MPa, and the space velocity was 8.0 h. -1 Taking the export bromine index of 200 mg Br / 100 g oil as the standard, the reaction stability reaches 312 hours.

[0088] [Example 5]

[0089] Sodium hydroxide, aluminum isopropoxide and water are stirred and dissolved at room temperature to obtain solution A, tetraethyl silicate and tetraethylammonium hydroxide (25wt%) are evenly dispersed in water to obtain solution B, solution B is added dropwise to solution A to obtain a gelling solution with a molar composition of NaOH:TEAOH:Al2O3:SiO2:H2O=0.28:4.1:1:12.5:210, crystallized at 110°C for 4 days, filtered to obtain a white solid and a filtrate, respectively placed above and below the porous partition, treated in a crystallization kettle at 110°C in a filtrate steam environment for 4 hours, dried at 120°C for 12 hours, and calcined at 550°C in an air atmosphere for 4 hours to obtain a mesoporous BEA molecular sieve MB-5. The average pore size R of MB-5 is 5.5nm, and the specific surface area S of the mesopores is 2.3nm. 介孔 389m 2 / g,S 介孔 / S 微孔 The pH value is 5.86, the Na content is 0.14%, and based on the NH3-TPD results, the ratio of weak acid to medium-strong acid is 1.44:1.

[0090] MB-5 and alumina are molded and calcined according to a formula of 70% and 30% by weight on a dry basis to obtain the catalyst CMB-5 for removing olefins from aromatic materials.

[0091] 5g of the above catalyst was used to carry out a non-hydrogenation deolefination test of reformed oil in a fixed bed reactor. The raw material bromine index was 1300 mg Br / 100 g oil. The reaction temperature was 170°C, the reaction pressure was 2.0 MPa, and the space velocity was 8.0 h. -1 Taking the export bromine index of 200 mg Br / 100 g oil as the standard, the reaction stability reaches 396 hours.

[0092] [Comparative Example 1]

[0093] Sodium hydroxide, aluminum sulfate 18hydrate and water were stirred and dissolved at room temperature to obtain solution A, silica sol (SiO2 content 40wt%) and tetraethylammonium hydroxide (25wt%) were evenly dispersed in water to obtain solution B, solution B was added dropwise to solution A to obtain a gelling solution with a molar composition of NaOH:TEAOH:Al2O3:SiO2:H2O=0.6:2:1:12.5:250, crystallized at 100°C for 6 days, filtered to obtain a white solid, dried at 120°C for 12 hours, and calcined at 550°C in air atmosphere for 4 hours to obtain BEA molecular sieve DMB-1. The average pore size R of DMB-1 is 1.2nm, and the specific surface area S of the mesopores is 2.3nm. 介孔 67m 2 / g,S 介孔 / S 微孔 The pH value is 0.14, the Na content is 0.72%, and according to the NH3-TPD results, the ratio of weak acid to medium-strong acid is 0.57:1.

[0094] According to the formula of 70% and 30% by weight on dry basis, DMB-1 and alumina are molded and calcined to obtain the catalyst CDMB-1 for deolefination of aromatic materials.

[0095] 5g of the above catalyst was used to carry out a non-hydrogenation deolefination test of reformed oil in a fixed bed reactor. The raw material bromine index was 1300 mg Br / 100 g oil. The reaction temperature was 170°C, the reaction pressure was 2.0 MPa, and the space velocity was 8.0 h. -1 Taking the export bromine index of 200 mg Br / 100 g oil as the standard, the reaction stability reaches 108 hours.

[0096] [Comparative Example 2]

[0097] Repeat the formula of Example 1, stir and dissolve sodium hydroxide, aluminum sulfate 18hydrate and water at room temperature to obtain solution A, disperse silica sol (SiO2 content 40wt%) evenly in water to obtain solution B, add solution B dropwise to solution A to obtain a gelling solution with a molar composition of NaOH:Al2O3:SiO2:H2O=0.6:1:12.5:250, dry the gelling solution at 80°C for 24 hours and then crush it into a white powder. Tetraethylammonium hydroxide (25wt%) is diluted to 10wt%, and placed below and above the porous interlayer with the white powder, respectively, crystallized at 100°C in a crystallization kettle for 6 days, filtered, dried at 120°C for 12 hours, and calcined at 550°C in air atmosphere for 4 hours to obtain molecular sieve DMB-2. XRD results show that DMB-2 is amorphous. N2 adsorption results show that the average pore size R is 10.2nm, and the specific surface area S of the mesopores is 1.3nm. 介孔 77m 2 / g.S 介孔 / S 微孔The XRF results showed that the Na content was 1.37%. The NH3-TPD results showed a broad, diffuse NH3 desorption peak, which could not distinguish between weak acid and medium-strong acid.

[0098] [Comparative Example 3]

[0099] Sodium hydroxide, aluminum isopropoxide and water are stirred and dissolved at room temperature to obtain solution A, tetraethyl silicate and tetraethylammonium hydroxide (25wt%) are evenly dispersed in water to obtain solution B, solution B is added dropwise to solution A to obtain a gelling solution with a molar composition of NaOH:TEAOH:Al2O3:SiO2:H2O=0.28:4.1:1:12.5:210, crystallized at 110°C for 4 days, filtered to obtain a white solid and a filtrate, the white solid is placed in 100°C deionized water for 4 hours, dried at 120°C for 12 hours, and calcined at 550°C in air atmosphere for 4 hours to obtain a mesoporous BEA molecular sieve DMB-3. The average pore size R of DMB-3 is 2.7nm, and the specific surface area S of the mesopores is 2.7nm. 介孔 138m 2 / g,S 介孔 / S 微孔 The pH value is 0.36, the Na content is 0.11%, and based on the NH3-TPD results, the ratio of weak acid to medium-strong acid is 0.47:1.

[0100] According to the formula of 70% and 30% by weight on dry basis, DMB-3 and alumina are molded and calcined to obtain the catalyst CDMB-3 for deolefination of aromatic materials.

[0101] 5g of the above catalyst was used to carry out a non-hydrogenation deolefination test of reformed oil in a fixed bed reactor. The raw material bromine index was 1300 mg Br / 100 g oil. The reaction temperature was 170°C, the reaction pressure was 2.0 MPa, and the space velocity was 8.0 h. -1 Taking the export bromine index of 200 mg Br / 100 g oil as the standard, the reaction stability reaches 144 hours.

[0102] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

Claims

1. A mesoporous BEA molecular sieve, wherein the average pore size R of the mesoporous BEA molecular sieve is 2 to 8 nm, and the specific surface area S of the mesopores is 介孔 150~500m 2 / g, the ratio of the specific surface area of ​​mesopores to micropores in the mesoporous BEA molecular sieve is S 介孔 / S 微孔 The content of Na in the mesoporous BEA molecular sieve is less than 1.0%.

2. The mesoporous BEA molecular sieve according to claim 1, characterized in that: The average pore size R of the mesoporous BEA molecular sieve is 3 to 6 nm, and the specific surface area S of the mesopores is 介孔 250~450m 2 / g, the ratio of the specific surface area of ​​mesopores to micropores in the mesoporous BEA molecular sieve is S 介孔 / S 微孔 The content of Na in the mesoporous BEA molecular sieve is less than 0.5%.

3. The mesoporous BEA molecular sieve according to claim 1 or 2, characterized in that: Based on the NH3-TPD results, the ratio of weak acid to medium-strong acid in the mesoporous BEA molecular sieve is (0.8-2):1, preferably (1.02-1.5):

1.

4. A method for preparing a mesoporous BEA molecular sieve, preferably for preparing the mesoporous BEA molecular sieve according to any one of claims 1 to 3, the method comprising: (1) mixing an alkali, an aluminum source, a silicon source, a template, and water to obtain a dispersion; (2) performing crystallization and filtering separation to obtain a filtrate and a solid intermediate; (3) placing the solid intermediate in a steam environment for steam treatment, and then drying and calcining to obtain the mesoporous BEA molecular sieve.

5. The preparation method according to claim 4, characterized in that: The alkali is selected from at least one of sodium hydroxide, potassium hydroxide, ammonia water, urea, methylamine, ethylamine, and ethylenediamine; and / or the aluminum source is selected from at least one of sodium aluminate, aluminum sulfate, aluminum nitrate, aluminum sol, and aluminum isopropoxide; and / or the silicon source is selected from at least one of sodium silicate, silica sol, white carbon black, water glass, and tetraethyl silicate; and / or the template is selected from at least one of tetraethylammonium hydroxide and tetraethylammonium bromide.

6. The preparation method according to claim 4, characterized in that: The molar ratio of the base to the aluminum source is (0.01-1):1, preferably (0.1-0.6):1; and / or the molar ratio of the template to the aluminum source is (0.1-10):1, preferably (2-5):1; and / or the molar ratio of the silicon source to the aluminum source is (2-20):1, preferably (8-15):1; and / or the molar ratio of the water to the aluminum source is (50-500):1, preferably (100-300):1; wherein the molar amounts of the base, the template and the water are respectively measured by the molar amounts of their molecules, the molar amount of the aluminum source is measured by the molar amount of Al2O3, and the molar amount of the silicon source is measured by the molar amount of SiO2.

7. The preparation method according to claim 4, characterized in that: In step (2), the crystallization conditions include: temperature of 90-120° C., and time of 3-10 days; preferably, the crystallization conditions include: temperature of 100-120° C., and time of 3-6 days.

8. The preparation method according to any one of claims 4 to 7, characterized in that: The steam environment in step (3) is a water vapor environment or the steam environment of the filtrate in step (2); preferably, the treatment is carried out in a steam environment at 100 to 160° C. for 2 to 10 hours.

9. A catalyst comprising a mesoporous BEA molecular sieve and a binder, wherein the mesoporous BEA molecular sieve is the mesoporous BEA molecular sieve according to any one of claims 1 to 3 or the mesoporous BEA molecular sieve obtained by the preparation method according to any one of claims 4 to 8.

10. The catalyst according to claim 9, characterized in that The binder is selected from at least one of aluminum oxide, silicon oxide, zirconium oxide and titanium oxide; and / or, Based on 100wt% of the catalyst, the mesoporous BEA molecular sieve accounts for 50-95wt% and the binder accounts for 5-50wt%.

11. Use of the mesoporous BEA molecular sieve according to any one of claims 1 to 3, or the mesoporous BEA molecular sieve obtained by the preparation method according to any one of claims 4 to 8, or the catalyst according to any one of claims 9 to 10 in the deolefination of aromatic hydrocarbons.

12. A method for deolefination of aromatic hydrocarbons, comprising: The raw aromatic hydrocarbon is contacted and reacted with the mesoporous BEA molecular sieve described in any one of claims 1 to 3, or the mesoporous BEA molecular sieve obtained by the preparation method described in any one of claims 4 to 8, or the catalyst described in any one of claims 9 to 10.

13. The method according to claim 12, characterized in that The reaction conditions include: temperature of 150-270°C, pressure of 0.6MPa-3.0MPa, weight space velocity of 1-20h -1 .