CN111825102B

CN111825102B - Dry glue conversion synthesis method of high-silicon Y molecular sieve

Info

Publication number: CN111825102B
Application number: CN201910312322.2A
Authority: CN
Inventors: 王林英; 田鹏; 朱大丽; 刘中民; 王全义; 桑石云
Original assignee: Dalian Institute of Chemical Physics of CAS
Current assignee: Dalian Institute of Chemical Physics of CAS
Priority date: 2019-04-18
Filing date: 2019-04-18
Publication date: 2022-03-22
Anticipated expiration: 2039-04-18
Also published as: CN111825102A

Abstract

The application discloses a dry glue conversion synthesis method of a high-silicon Y molecular sieve, belonging to the field of molecular sieve synthesis. The method comprises the following steps: a) mixing raw materials containing an aluminum source, a silicon source, an alkali metal source, an organic template agent R2 and water to obtain initial gel, then adding a guiding agent or a silicon-aluminum molecular sieve seed crystal with an FAU or EMT structure, and stirring to obtain synthetic gel; b) removing water from the synthetic gel to obtain a dry powder mixture; c) crystallizing the dry powder mixture. According to the method, the synthesis of the high-silicon Y molecular sieve with the silicon-aluminum ratio of 8-40 is realized; compared with a conventional water quantity system, the ultralow water quantity system adopted by the method has the advantages that the crystallization rate of a target product is higher, and the silicon-aluminum ratio is higher; and the method has simple process and is beneficial to large-scale industrial production.

Description

Dry glue conversion synthesis method of high-silicon Y molecular sieve

Technical Field

The application relates to a dry gel conversion synthesis method of a high-silicon Y molecular sieve, in particular to a method for synthesizing the high-silicon Y molecular sieve under ultra-low water content by introducing an organic template agent into a synthetic gel system and adding a guiding agent or a seed crystal, belonging to the field of molecular sieve synthesis.

Background

The Y molecular sieve is a silico-aluminum molecular sieve with FAU topology, mainly applied to Fluid Catalytic Cracking (FCC), and is the most used molecular sieve material at present. The framework silica-alumina ratio of the Y molecular sieve plays a decisive role in the catalytic performance, wherein the higher the silica-alumina ratio is, the better the catalytic activity and the stability are. At present, the high-silicon Y molecular sieve used in industry is mainly obtained by chemical/physical dealumination and the like, the post-treatment method has the defects of complicated process, high energy consumption and heavy pollution, and the direct hydrothermal synthesis can effectively avoid the defects and simultaneously maintain the integrity of a crystal structure and the uniformity of aluminum distribution. Therefore, the exploration of direct method for synthesizing the Y molecular sieve with high silica-alumina ratio has very important significance for the catalytic cracking process.

For synthesizing the high-silicon Y molecular sieve by the direct method, people firstly synthesize the high-silicon Y molecular sieve in a non-template system, namely, no organic template is added into reaction gel, and the aim of improving the silicon-aluminum ratio of the Y molecular sieve is achieved only by adjusting the gel proportion, the crystallization time, the preparation method of seed crystals or inorganic directing agents and the like, but the yield is very low, and the silicon-aluminum ratio is difficult to reach 6.

The use of the organic structure directing agent brings the synthesis of the Y molecular sieve into the brand-new field, and in 1987, the U.S. Pat. No. 4, 4,714,601 discloses an ECR-4 FAU polymorph with a silicon-aluminum ratio of more than 6, which is obtained by taking alkyl or hydroxyalkyl quaternary ammonium salt as a template agent and carrying out hydrothermal crystallization at 70-120 ℃ in the presence of seed crystals.

In 1990, US 4,931,267 discloses a FAU polymorph named ECR-32 with a Si/Al ratio greater than 6, which is obtained by hydrothermal crystallization at 90-120 ℃ using tetrapropyl and/or tetrabutyl ammonium hydroxide as a structure directing agent and has high thermal stability.

In 1990, French Delprato et al (Zeolite, 1990,10(6):546-552) synthesized FAU molecular sieve with cubic structure for the first time by using crown ether as a template, the framework silica-alumina ratio is close to 9.0, which is the highest value that can be realized by the one-step method reported in the literature at present, but the expensive and extremely toxic properties of the crown ether limit the industrial application.

Disclosure of Invention

According to one aspect of the application, a dry gel conversion synthesis method of a high-silicon Y molecular sieve is provided, and the method synthesizes the high-silicon (the silicon-aluminum ratio is 8-40) Y molecular sieve under the ultra-low water content by introducing an organic template agent into a synthesis gel system and adding a guiding agent or a seed crystal.

The dry glue conversion synthesis method of the high-silicon Y molecular sieve is characterized by comprising the following steps:

a) mixing raw materials containing an aluminum source, a silicon source, an alkali metal source, an organic template agent R2 and water to obtain initial gel, then adding a guiding agent or a silicon-aluminum molecular sieve seed crystal with an FAU or EMT structure, and stirring to obtain synthetic gel;

b) removing water from the synthetic gel to obtain a dry powder mixture;

c) and crystallizing the dry powder mixture to obtain the high-silicon Y molecular sieve.

Optionally, the preparation of the directing agent comprises the steps of:

a0) the directing agent is obtained by mixing raw materials containing an aluminum source, a silicon source, an alkali metal source, an organic template agent R1 and water, and then aging.

Optionally, the silicon source in step a) and step a0) is independently selected from at least one of methyl orthosilicate, ethyl orthosilicate, silica sol, solid silica gel, silica white and sodium silicate.

Optionally, the aluminum sources in step a) and step a0) are independently selected from at least one of sodium metaaluminate, alumina, aluminum hydroxide, aluminum isopropoxide, aluminum 2-butoxide, aluminum chloride, aluminum sulfate, and aluminum nitrate.

Optionally, the alkali metal source in step a) and step a0) is independently selected from at least one of sodium hydroxide, potassium hydroxide, and cesium hydroxide.

Optionally, the organic templating agent R1 is selected from at least one of the quaternary ammonium compounds having the formula shown in formula I:

wherein R is¹¹、R¹²、R¹³And R¹⁴Independently selected from C₁～C₁₂Alkyl of (C)₁～C₁₂Alkoxy group of (C)₁～C₁₂At least one of hydroxyalkyl groups of (a); x^n-Selected from OH^-、Cl^-、Br^-、I^-、NO₃ ^-、HSO₄ ^-、H₂PO₃ ^-、SO₄ ^2-、HPO₃ ^2-、PO₃ ^3-。

Preferably, the organic templating agent R1 is selected from at least one of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide.

Optionally, the organic template R2 is at least one selected from quaternary ammonium compounds and nitrogen-containing heterocyclic compounds with the structural formula shown in formula II:

wherein R is²¹、R²²、R²³And R²⁴Independently selected from C₁～C₁₂Alkyl of (C)₁～C₁₂Alkoxy group of (C)₁～C₁₂At least one of hydroxyalkyl, aryl, phenylalkyl and adamantyl; x^n-Selected from OH^-、Cl^-、Br^-、I^-、NO₃ ^-、HSO₄ ^-、H₂PO₃ ^-、SO₄ ^2-、HPO₃ ^2-、PO₃ ^3-。

Preferably, the nitrogen-containing heterocyclic compound is selected from at least one of pyridine, piperidine, imidazole, piperazine and derivatives thereof.

More preferably, the organic templating agent R2 is selected from the group consisting of tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, tetrapentylammonium hydroxide, tetrahexylammonium hydroxide, tetrapropylammonium bromide, tetrabutylammonium chloride, tetrapentylammonium bromide, tripropylisobutylammonium bromide, tributylcyclohexylammonium hydroxide, dibutyldihexylammonium hydroxide, choline, triethylhydroxyethylammonium hydroxide, tripropylhydroxyethylammonium hydroxide, tributylhydroxyethylammonium hydroxide, tributylbenzylammonium hydroxide, triethylbenzylammonium hydroxide, tripropylbenzylammonium hydroxide, triethyladamantylammonium chloride, tripropyladamantylammonium chloride, pyridine, N-methylpyridine, N-ethylpyridine, N-propylpyridine, N-butylpyridine, 1-ethyl-3-butylpyridine hydroxide, 1-ethyl-2-propylpyridine hydroxide, tetrabutyl adamantylammonium chloride, and mixtures thereof, Piperidine, N-dimethylpiperidine, N-dimethyl-3, 5-diethylpiperidine hydroxide, N-dimethyl-3, 5-dipropylpiperidine hydroxide, N-diethyl-3, 5-dipropylpiperidine hydroxide, N-dimethyl-2, 6-dimethylpiperidine hydroxide, N-hydroxide, at least one of N-dimethyl-2, 6-diethylpiperidine, imidazole, 1-ethyl-3-butylimidazole hydroxide, 1-ethyl-3-butyl-4-propylimidazole hydroxide, piperazine, N-methylpiperazine, 1, 4-dipropylpiperazine, 1-methyl-4-ethylpiperazine and 1-ethyl-4-butyl-5-methylpiperazine.

Optionally, the silico-alumina molecular sieve seed crystal with FAU or EMT structure has a silico-alumina ratio of 2 or more.

Optionally, the silicon-aluminum ratio of the silicon-aluminum molecular sieve seed crystal with the FAU or EMT structure is 2.5-200.

Preferably, the silicoaluminophosphate molecular sieve seeds having the FAU or EMT structure have an upper limit of the silicoaluminophosphate ratio selected from 200, 180, 150, 120, 100, 80, 50, 30, 20, 10, 8, 6, 5, 4, 3 and a lower limit selected from 2.5, 3, 4, 5, 6, 8, 10, 20, 30, 50, 80, 100, 120, 150, 180.

Optionally, the aluminosilicate molecular sieve seed crystal with FAU or EMT structure is selected from Na type, NH type₄At least one of type and H zeolite molecular sieves.

Alternatively, in step a0), the aluminum source, the silicon source, the alkali metal source, the organic template R1 and water are mixed according to the following molar ratios:

1Al₂O₃:(10～30)SiO₂:(0～5)M₂O:(5～30)R1:(100～600)H₂O；

wherein the mole number of the silicon source is SiO₂Counting; the mole number of the aluminum source is Al₂O₃Counting; the mole number of the organic template R1 is calculated by the mole number of R1 per se; the molar number of the alkali metal source is equal to the metal oxide M corresponding to the corresponding alkali metal M₂And the mole number of O.

Preferably, in step a0), the aluminum source, the silicon source, the alkali metal source, the organic template R1 and water are mixed according to the following molar ratios:

1Al₂O₃:(10～30)SiO₂:(0～5)M₂O:(6～30)R1:(100～600)H₂O；

Optionally, in the step a0), the aging temperature is 25-120 ℃.

Preferably, in step a0), the temperature of the aging is selected from the upper limit of 120 ℃, 110 ℃, 100 ℃, 90 ℃, 80 ℃, 70 ℃,60 ℃, 50 ℃, 40 ℃, 30 ℃ and the lower limit of 25 ℃, 30 ℃, 40 ℃, 50 ℃,60 ℃, 70 ℃, 80 ℃, 90 ℃, 100 ℃, 110 ℃.

Optionally, in the step a0), the aging time is 0.5-6 days.

Preferably, in step a0), the upper limit of the aging time is selected from 6 days, 5 days, 4 days, 3 days, 2.5 days, 2 days, 1.5 days, 1 day, and the lower limit is selected from 0.5 days, 1 day, 1.5 days, 2 days, 2.5 days, 3 days, 4 days, 5 days.

Preferably, in the step a0), the aging time is 0.5-3 days.

Optionally, in step a0), the aging is performed in a dynamic or static manner.

In one embodiment, the aging is performed in a static manner, for example, in a standing manner.

In one embodiment, the aging is carried out in a dynamic manner, for example, in a stirring or rotating manner.

Optionally, in step a0), the aging is performed in a combination of dynamic and static.

Optionally, in step a), the aluminum source, the silicon source, the alkali metal source, the organic templating agent R2, and water are mixed in the following molar ratios:

1Al₂O₃:(10～100)SiO₂:(1～12)M₂O:(2～20)R2:(100～2800)H₂O；

wherein the mole number of the silicon source is SiO₂Counting; the mole number of the aluminum source is Al₂O₃Counting; the mole number of the organic template R2 is calculated by the mole number of R2 per se; the number of moles of alkali metal sourceMetal oxide M corresponding to alkali metal M₂And the mole number of O.

Preferably, in step a), the aluminum source, the silicon source, the alkali metal source, the organic templating agent R2, and water are mixed in the following molar ratios:

1Al₂O₃:(10～100)SiO₂:(1～12)M₂O:(2～20)R2:(100～2500)H₂O；

wherein the mole number of the silicon source is SiO₂Counting; the mole number of the aluminum source is Al₂O₃Counting; the mole number of the organic template R2 is calculated by the mole number of R2 per se; the molar number of the alkali metal source is equal to the metal oxide M corresponding to the corresponding alkali metal M₂And the mole number of O.

Optionally, in step a), the amount of the guiding agent added is such that SiO in the guiding agent₂In an amount of SiO in the initial gel₂3-20 wt% of the content.

Preferably, in step a), SiO in the directing agent₂The content of SiO in the initial gel₂The upper limit of the mass fraction of the content is selected from 20 wt%, 19 wt%, 18 wt%, 17 wt%, 16 wt%, 15 wt%, 14 wt%, 13 wt%, 12 wt%, 11 wt%, 10 wt%, 9 wt%, 8 wt%, 7 wt%, 6 wt%, 5 wt%, 4 wt%, and the lower limit is selected from 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%.

Alternatively, SiO in the directing agent when preparing the synthetic gel₂The content of SiO in the initial gel₂3-20% of the content.

Preferably, the SiO in the directing agent is used in the preparation of the synthesis gel₂The content of SiO in the initial gel₂3-10% of the content.

Optionally, in step a), the directing agent is added to the initial gel in the form of a solution.

Optionally, in step a), the amount of the aluminosilicate molecular sieve seeds having the FAU or EMT structure added is SiO in the initial gel₂3-20 wt% of the content.

Preferably, in step a), the seeds of the silicoaluminophosphate molecular sieve having the FAU or EMT structure are added in an amount relative to the SiO in the initial gel₂The content is selected from the group consisting of 20 wt%, 19 wt%, 18 wt%, 17 wt%, 16 wt%, 15 wt%, 14 wt%, 13 wt%, 12 wt%, 11 wt%, 10 wt%, 9 wt%, 8 wt%, 7 wt%, 6 wt%, 5 wt%, 4 wt% at the upper limit and 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt% at the lower limit.

Optionally, the amount (mass fraction) of seed crystals added in step a) is based on the SiO in the initial gel₂3-20% of the content.

Preferably, the amount (mass fraction) of seed crystals added in step a) is based on the SiO in the initial gel₂3-10% of the content.

Optionally, in the step a), the stirring is performed for 1 to 3 hours.

Preferably, in step a), the stirring is carried out for a time with an upper limit selected from 3 hours, 2.5 hours, 2 hours, 1.5 hours and a lower limit selected from 1 hour, 1.5 hours, 2 hours, 2.5 hours.

Optionally, in step b), removing water from the synthesis gel to H therein₂O and SiO₂The molar ratio of (a) to (b) is 1:1 to 3: 1.

Preferably, in step b), the synthesis gel with water removed has an upper limit of the water to silicon ratio selected from 3.0, 2.9, 2.8, 2.7, 2.6, 2.5, 2.4, 2.3, 2.2, 2.1, 2.0, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1 and a lower limit selected from 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9.

Optionally, in step b), the water removal is performed by evaporation with heating.

Optionally, in the step b), the temperature of the evaporation is 50-100 ℃.

Preferably, in step b), the temperature of evaporation has an upper limit selected from 100 ℃, 90 ℃, 80 ℃, 70 ℃,60 ℃ and a lower limit selected from 50 ℃,60 ℃, 70 ℃, 80 ℃, 90 ℃.

Preferably, in the step b), the temperature of the evaporation is 50-90 ℃.

Optionally, in step b), the evaporation manner is static evaporation or stirring evaporation.

Optionally, in the step c), the crystallization temperature is 90-180 ℃.

Preferably, in step c), the crystallization temperature has an upper limit selected from 180 ℃, 170 ℃, 160 ℃, 150 ℃, 140 ℃, 135 ℃, 130 ℃, 125 ℃, 120 ℃, 115 ℃, 110 ℃, 105 ℃, 100 ℃, 95 ℃, and a lower limit selected from 90 ℃, 95 ℃, 100 ℃, 105 ℃, 110 ℃, 115 ℃, 120 ℃, 125 ℃, 130 ℃, 135 ℃, 145 ℃, 155 ℃, 165 ℃, 175 ℃.

Preferably, in the step c), the crystallization temperature is 100-130 ℃.

Optionally, in the step c), the crystallization time is 0.1 to 10 days.

Preferably, in step c), the upper limit of the crystallization time is selected from 10 days, 9 days, 8 days, 7 days, 6 days, 5 days, 4 days, 3 days, 2 days, 1 day, 0.8 day, 0.5 day, 0.2 day, and the lower limit is selected from 0.1 day, 0.2 day, 0.5 day, 0.8 day, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days.

Preferably, in the step c), the crystallization time is 0.5 to 6 days.

Optionally, in step c), the crystallization is performed under autogenous pressure.

In the method, the crystallization mode in step c) may be dynamic crystallization or static crystallization, or may be a combination of two crystallization modes.

Optionally, in step c), the crystallization is performed in a dynamic or static manner.

Optionally, in step c), the crystallization is performed in a combination of dynamic and static manner, for example, in a first static and then dynamic manner.

In the present application, dynamic crystallization refers to that the slurry in the crystallization kettle is in a non-standing state, and static crystallization refers to that the slurry in the crystallization kettle is in a standing state. By way of example, the dynamic crystallization may be performed by rotational crystallization.

Optionally, in step c), after the crystallization, filtering, washing and drying the solid product to obtain the high-silicon Y molecular sieve.

In the method, the washing, filtering, separating and drying of the obtained Y molecular sieve are all conventional operations. In one embodiment, the separation is selected from centrifugation or suction filtration. In another embodiment, the drying temperature is 100 to 110 ℃ and the time is 12 hours.

In a specific embodiment, the synthesis of the high silicon Y molecular sieve is as follows:

1) preparing a guiding agent: aluminum source, silicon source, organic ammonium (R1) as 1Al₂O₃:(10～30)SiO₂:(0～5.0)Na₂O:(5～30)R1:(100～600)H₂Mixing and stirring the mixture for 2 hours according to the molar ratio of O, and stirring the mixture for 0.5 to 3 days at the temperature of between 25 and 120 ℃ to prepare a guiding agent A;

2) preparing a synthetic gel: aluminum source, silicon source, sodium hydroxide, organic ammonium (R2) as 1Al₂O₃:(10-100)SiO₂:(1.0-12.0)Na₂O:(2.0-20)R2:(100-2500)H₂Mixing and stirring the mixture evenly at room temperature according to the molar ratio of O to obtain initial gel B, and then adding a certain amount of guiding agent (wherein Al in the guiding agent)₂O₃The content of the initial gel Al₂O₃3-20% of the content) or seed crystal (the mass of the seed crystal is initial gel SiO)₂3-20% of the content) is stirred for 1-3 hours to prepare synthetic gel C;

3) the synthetic gel removed excess water: heating the synthesized gel at a certain temperature to remove excessive water to obtain a system H₂O/SiO₂1-3 (molar ratio), and obtaining a dry powder mixture D;

4) synthesis of high-silicon Y zeolite: and crystallizing the dry powder mixture at a certain temperature under autogenous pressure for 2-10 days, filtering and separating a solid product after crystallization is finished, washing the solid product to be neutral by using deionized water, and drying the product to obtain the high-silicon Y zeolite.

According to another aspect of the application, a high-silicon Y molecular sieve prepared by the method is provided, and has an FAU topological structure, and the silicon-aluminum ratio of the high-silicon Y molecular sieve is up to 8-40.

The anhydrous chemical composition of the high-silicon Y molecular sieve is shown as a formula III:

kM·mR1·nR2·(Si_xAl_y)O₂formula III

Wherein M is at least one selected from alkali metal elements;

k represents (Si) per mole_xAl_y)O₂K is 0 to 0.2 in terms of the number of moles of the corresponding alkali metal element;

m and n represent each mole of (Si)_xAl_y)O₂The mole number of the corresponding organic template R1 and organic template R2 is 0-0.2; n is 0.01 to 0.2;

x and y represent the mole fractions of Si and Al, respectively, 2x/y is 8-40, and x + y is 1.

Optionally, M is Na, K and/or Cs, preferably Na.

Optionally, k is 0.01-0.15; m is 0 or 0.01 to 0.1; n is 0.02 to 0.15.

Optionally, k is 0.02-0.13; m is 0 or 0.01 to 0.04; n is 0.03 to 0.08.

Optionally, under the condition that x + y is 1, the upper limit of 2x/y is selected from 40, 39, 38, 37, 36, 35, 34, 33, 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, and the lower limit is selected from 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39.

According to yet another aspect of the present application, there is provided a catalyst comprising a high silicon Y molecular sieve prepared by the above method.

The high silicon Y molecular sieve having FAU topology prepared according to the process described herein can be used in fluid catalytic cracking catalysts as well as supports and catalysts for bifunctional catalysis of reactions such as hydrocracking, hydrodesulfurization, and the like.

In the context of the present application, the term "silicon to aluminum ratio" means in SiO in a molecular sieve₂And Al₂O₃The molar ratio of silicon to aluminum is calculated and is synonymous with "2 x/y" and "silicon to aluminum oxide ratio" as described herein.

In the context of the present application, the term "water to silicon ratio" means the H content of the resultant gel after removal of water₂O and SiO₂The ratio of the molar ratio of (a) to (b).

In this application, C₁～C₁₂、C₁～C₄And the like refer to the number of carbon atoms involved. Such as "C₁～C₄The "alkyl group" refers to an alkyl group having 1 to 4 carbon atoms.

In the present application, the "alkyl group" is a group formed by losing any one hydrogen atom on the molecule of an alkane compound including a straight-chain alkane, a branched-chain alkane, a cycloalkane, and a branched-chain cycloalkane.

As used herein, an "alkoxy" group is a group formed by the loss of a hydrogen atom from an-OH group in an alkyl alcohol compound molecule, such as CH₃methoxy-OCH formed by loss of a hydrogen atom from the-OH group on the OH molecule₃。

As used herein, "hydroxyalkyl" is a radical of an alkyl alcohol compound formed by the loss of any hydrogen atom of a non-OH group on the molecule, e.g., CH₃Hydroxymethyl HOCH formed by loss of hydrogen atom from methyl group on OH molecule₂—。

As used herein, an "aryl group" is a group formed by the loss of one hydrogen atom on an aromatic ring on an aromatic compound molecule, such as a p-tolyl group formed by the loss of a hydrogen atom para to a methyl group on a benzene ring from toluene.

In the present application, "phenylalkyl" is a group formed by the loss of any hydrogen atom from an alkyl substituent on a phenyl ring, such as benzyl (benzyl) formed by the loss of one hydrogen atom from a methyl group on toluene.

The beneficial effects that can be produced by the application include but are not limited to:

1) according to the dry gel conversion synthesis method of the high-silicon Y molecular sieve, the organic template agent is introduced into the synthesized gel, and the guiding agent or the crystal seed is added, so that the synthesis of the high-silicon Y molecular sieve with the silicon-aluminum ratio of 8-40 is realized under the condition of ultralow water content.

2) Compared with a conventional water quantity system, the ultralow water quantity system of the dry glue conversion synthesis method of the high-silicon Y molecular sieve has the advantages that the crystallization rate of a target product Y molecular sieve is higher, and the silicon-aluminum ratio of the product is higher.

3) The dry glue conversion synthesis method of the high-silicon Y molecular sieve is simple in process and beneficial to large-scale industrial production.

Drawings

Fig. 1 is an X-ray diffraction (XRD) pattern of sample S1 #.

Fig. 2 is an X-ray diffraction (XRD) pattern of comparative sample # 1.

Fig. 3 is an X-ray diffraction (XRD) pattern of comparative sample No. 2.

Fig. 4 is an X-ray diffraction (XRD) pattern of comparative sample # 3.

Fig. 5 is an X-ray diffraction (XRD) pattern of comparative sample # 4.

Fig. 6 is an X-ray diffraction (XRD) pattern of sample Y1 #.

Fig. 7 is an X-ray diffraction (XRD) pattern of comparative sample # 5.

Fig. 8 is an X-ray diffraction (XRD) pattern of comparative sample No. 6.

Fig. 9 is an X-ray diffraction (XRD) pattern of comparative sample No. 7.

Detailed Description

As mentioned above, the present application relates to a high silicon Y molecular sieve with FAU topology and its synthesis method, the anhydrous chemical composition of the molecular sieve is kNa. mR 1. nR2 (Si)_xAl_y)O₂Wherein Na is sodium ion and k represents per mole (Si)_xAl_y)O₂The mole number of Na ions; r1 and R2 represent organic templating agents, respectively, which are present in the microporous structure, and m and n represent each mole (Si)_xAl_y)O₂Moles of mesoorganic templating agents R1 and R2; the silicon-aluminum oxide ratio (2x/y) is 8-40; the molecular sieve can be synthesized at ultra-low water content by introducing organic ammonium into a synthesis gel system and adding a directing agent or seed crystal.

The present application will be described in detail with reference to examples, but the present application is not limited to these examples.

Unless otherwise specified, the raw materials and reagents in the examples of the present application were purchased commercially, wherein the Y zeolite having the FAU structure as the seed crystal was purchased from ziborun xin chemical technology ltd, and the ratio of silicon to aluminum oxide was 5; the EMT zeolite having an EMT structure was purchased from molecular sieves ltd of huanan world with a silica-alumina oxide ratio of 3.

The analysis method in the examples of the present application is as follows:

x-ray powder diffraction phase analysis (XRD) an X' Pert PRO X-ray diffractometer from pananace, netherlands, Cu target, K α radiation source (λ ═ 0.15418nm), voltage 40kV, current 40mA was used.

The elemental composition was determined using a Philips Magix 2424X-ray fluorescence Analyzer (XRF).

Analyzing the content of the organic template agent in the sample by adopting a TA Q-600 thermal analyzer, and heating from room temperature to 900 ℃ at the heating rate of 10 ℃/min.

Using nuclear magnetism of carbon: (¹³C MAS NMR) analysis of the ratio of two organic templating agents, carbon Nuclear magnetism (C-MAS NMR)¹³C MAS NMR) experiments were performed on a Bruker Avance III 600(14.1Tesla) spectrometer using a 4mm triple resonance probe, rotating at 12kHz, with amantadine as chemical shift reference, corrected to 0 ppm.

EXAMPLE 1 preparation of sample S1#

Preparing a guiding agent: 0.28g of sodium hydroxide (analytical grade, Mimeos chemical reagent Co., Ltd., Tianjin, Ltd.) and 0.71g of sodium aluminate (chemical grade, Shanghai chemical reagent Co., Ltd., China medicine (group)) were dissolved in 19.06g of tetramethylammonium hydroxide (25% aqueous solution, Aladdin reagent (Shanghai) Co., Ltd.) and stirred until they were clarified, and then 14.00g of ethyl orthosilicate (chemical grade, Shanghai chemical reagent Co., China medicine (group)) was added dropwise and stirred at room temperature for 2 hours. Standing the solution at 25 deg.C for 12 hr, and rotating and aging at 80 deg.C for 24 hr.

Preparing a synthetic gel: 0.55g of sodium aluminate, 0.27g of sodium hydroxide are added to a solution of 20.06g of tetrapropylammonium hydroxide (25% by weight), stirred until clear and 13.33g of silica Sol (SiO) are added dropwise₂：30wt％Shenyang chemical Co., Ltd.) was stirred for 2 hours to obtain an initial gel, and 3.47g of the above-mentioned directing agent was added thereto and stirred for 3 hours to obtain a synthetic gel.

The synthetic gel removed excess water: the resultant gel was heated at 50 ℃ to remove excess water, to give 13.47g of a dry powder mixture.

Synthesizing a high-silicon Y molecular sieve: transferring the dry powder mixture into a stainless steel reaction kettle, rotating and crystallizing for 4 days at 130 ℃, separating solid from liquid after crystallization is finished, washing to be neutral, and drying for 12 hours at 100 ℃ to be marked as sample S1 #.

The X-ray powder diffraction pattern (XRD) of sample S1# is shown in fig. 1, indicating that sample S1# is a molecular sieve having a FAU framework structure. Combining XRF, TG and¹³c MAS NMR analysis normalization yielded sample S1# with an elemental composition: 0.06 Na0.02R 1¹.0.05R2¹·(Si_0.88Al_0.12)O₂Wherein R1¹Is tetramethylammonium hydroxide, R2¹Is tetrapropylammonium hydroxide.

Example 2 preparation of samples S2# -S30#

The raw material types, the molar ratios, the crystallization conditions, the water-silicon ratios and the crystal structures and the compositions of the products of the samples S2# -S30# are shown in Table 1, the aging temperature, the aging time, the aging mode and the addition amount of the guiding agent are shown in Table 2, and the material preparation process is the same as that of the sample S1# in example 1.

Comparative example 1 preparation of comparative sample # 1

The specific raw material types, molar ratios, blending processes and crystallization conditions were the same as those of sample S1# in example 1, except that no directing agent preparation step was used, and no directing agent was added in the subsequent gel synthesis preparation step. The resulting sample was designated as comparative sample # 1.

Comparative example 2 preparation of comparative sample 2#

The specific raw material types, molar ratios, blending processes and crystallization conditions were the same as those of sample S1# in example 1, except that after the blending in the guiding agent preparation step was completed, the mixture was stirred at room temperature for 2 hours without aging. The resulting sample was designated comparative sample # 2.

Comparative example 3 preparation of comparative sample # 3

The specific raw material types, molar ratios, blending processes and crystallization conditions were the same as those of sample S1# in example 1, except that excessive water was not removed after the synthesis gel was prepared and the solution was directly introduced into the kettle for crystallization. The resulting sample was designated as comparative sample # 3.

Comparative example 4 preparation of comparative sample No. 4

The specific raw material types, molar ratios, blending processes and crystallization conditions were the same as those of sample S1# in example 1, except that excessive water was not removed after the synthesis gel was prepared, and the crystallization was carried out in a kettle for crystallization, and the crystallization time was extended from 4 days to 8 days. The resulting sample was designated comparative sample # 4.

XRD analysis of samples S1# -S30# of example 3 and comparative samples 1# -4#

The phases of samples S1# -S30# and comparative samples 1# -4# were analyzed by X-ray diffraction method.

The results show that samples S1# -S30# prepared in examples 1 and 2 are both high purity and high crystallinity Y molecular sieves, which typically represent the XRD spectrum of sample S1# as in fig. 1. The XRD spectrum results of the samples S2# -S30# are similar to those in FIG. 1, namely, the positions and shapes of diffraction peaks are basically the same, and the relative peak intensity fluctuates within +/-5% according to the change of synthesis conditions, which indicates that the samples S1# -S30# have the structural characteristics of Y-type zeolite and have no mixed crystal.

XRD patterns of comparative sample No. 1, comparative sample No. 2, comparative sample No. 3 and comparative sample No. 4 are shown in fig. 2, fig. 3, fig. 4 and fig. 5, respectively. It can be seen that, the comparative sample 1# and the comparative sample 2# are amorphous, it can be seen that the addition of the directing agent is necessary in the synthesis of the high-silicon Y molecular sieve, and the directing agent must be aged at high temperature in the preparation process to play a role in inducing crystallization, which is the key for synthesizing the high-silicon Y molecular sieve. Comparative sample No. 3# although it already showed the characteristic diffraction peak of Y zeolite, a large amount of amorphous form was present under the same crystallization conditions, and a pure phase Y zeolite sample could be obtained by extending the crystallization time to 8 days. It can be seen that the synthesis of gel to remove excessive water content to form a dry powder mixture and then crystallization can significantly accelerate the crystallization rate of zeolite, which is an important factor for rapid synthesis of high-silicon Y molecular sieve. In addition, the Si/Al ratio of comparative sample No. 4 is only 12.5, which is significantly lower than that of sample No. S1, which also indicates that the ultra-low water content not only can significantly increase the crystallization rate, but also is another important factor for synthesizing the high-silicon Y molecular sieve.

EXAMPLE 4 preparation of sample Y1#

Preparing a synthetic gel: 0.55g of sodium aluminate, 0.27g of sodium hydroxide are added to a solution of 20.06g of tetrapropylammonium hydroxide (25% by weight), stirred until clear and 13.33g of silica Sol (SiO) are added dropwise₂: 30 wt%, shenyang chemical corporation), stirring for 2h to obtain an initial gel, adding 0.40g of Y zeolite having a silica-alumina ratio of 5 as a seed crystal, and stirring for 3h to obtain a synthetic gel.

The synthetic gel removed excess water: the resultant gel was heated at 50 ℃ to remove excess water, to give a dry powder mixture (12.88 g).

Synthesizing a high-silicon Y molecular sieve: transferring the dry powder mixture into a stainless steel reaction kettle, rotating and crystallizing for 5 days at 130 ℃, separating solid from liquid after crystallization is finished, washing to be neutral, and drying for 12 hours at 100 ℃ to be marked as sample Y1 #.

The X-ray powder diffraction pattern (XRD) of sample Y1# is shown in fig. 6, indicating that sample Y1# is a molecular sieve having the FAU framework structure. Combining XRF, TG and¹³c MAS NMR analysis normalized to give sample Y1# the elemental composition: 0.07 Na0.08R 2¹·(Si_0.89Al_0.11)O₂Wherein R2¹Is tetrapropylammonium hydroxide.

Example 5 preparation of samples Y2# -Y30#

The raw material types, the molar ratios, the seed crystal adding amounts, the crystallization conditions, the water-silicon ratios and the crystal structures and the compositions of the products of the samples Y2# -Y30# are shown in Table 3, and the batching process is the same as that of the sample Y1# in the example 4.

Comparative example 5 preparation of comparative sample No. 5

The specific raw material types, molar ratios, blending processes and crystallization conditions were the same as those of sample Y1# in example 4 except that no seed crystal was added, and the obtained sample was designated as comparative sample No. 5.

Comparative example 6 preparation of comparative sample No. 6

The specific raw material types, molar ratios, seed crystal addition amounts, blending processes and crystallization conditions were the same as those of sample Y1# in example 4, except that excessive water was not removed after the synthesis gel was prepared and the solution was directly introduced into a kettle for crystallization. The resulting sample was designated as comparative sample # 6.

Comparative example 7 preparation of comparative sample 7#

The specific raw material types, molar ratios, seed crystal addition amounts, batching processes and crystallization conditions were the same as those of sample Y1# in example 4 except that excessive water was not removed after the synthesis gel was prepared and the crystallization was directly conducted in a kettle for crystallization, and the crystallization time was extended from 5 days to 10 days. The resulting sample was designated comparative sample # 7.

XRD analysis of sample Y1# -Y30# of example 6 and comparative sample 5# -7#

The phases of samples Y1# -Y30# and comparative samples 5# -7# were analyzed by X-ray diffraction method.

The results show that samples Y1# -Y30# prepared in examples 4 and 5 are both high purity and high crystallinity Y molecular sieves, typically representing the XRD spectrum of sample Y1# as in fig. 6. The XRD spectrum results of the samples Y2# -Y30# are close to that of FIG. 6, namely, the positions and shapes of diffraction peaks are basically the same, and relative peak intensities fluctuate within a range of +/-5% according to the change of synthesis conditions, which shows that the samples Y1# -Y30# have the structural characteristics of Y-type zeolite and have no mixed crystal.

The XRD patterns of comparative sample No. 5, comparative sample No. 6 and comparative sample No. 7 are shown in fig. 7, fig. 8 and fig. 9, respectively. It can be seen that comparative sample # 5 is amorphous, and it can be seen that in the synthesis of the high silicon Y molecular sieve, the addition of the seed crystal is necessary and is also the key to be able to synthesize the high silicon Y molecular sieve. Comparative sample No. 6, although showing the characteristic diffraction peaks of Y zeolite, a large amount of amorphous form was present under the same crystallization conditions, and a pure phase Y zeolite sample could be obtained by extending the crystallization time to 10 days. It can be seen that the synthesis of gel to remove excessive water content to form a dry powder mixture and then crystallization can significantly accelerate the crystallization rate of zeolite, which is an important factor for rapid synthesis of high-silicon Y molecular sieve. In addition, the Si/Al ratio of the comparative sample No. 7 is only 13.5, which is significantly lower than that of the sample No. Y1, which also indicates that the ultra-low water content not only can significantly increase the crystallization rate, but also is another important factor for synthesizing the high-silicon Y molecular sieve.

TABLE 2S 1-S30 temperature, time, mode and amount of director aging

Although the present application has been described with reference to a few embodiments, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the application as defined by the appended claims.

Claims

1. A dry glue conversion synthesis method of a high-silicon Y molecular sieve is characterized by comprising the following steps:

b) removing water from the synthetic gel to obtain a dry powder mixture;

c) crystallizing the dry powder mixture to obtain the high-silicon Y molecular sieve;

in step a), the aluminum source, the silicon source, the alkali metal source, the organic template R2 and water are mixed according to the following molar ratio:

1Al₂O₃:(40～100)SiO₂:(1～12)M₂O:(2～20)R2:(100～2800)H₂O；

2. The method of claim 1, wherein the preparation of the directing agent comprises the steps of:

3. The method of claim 1, wherein the silicon source in step a) and step a0) is independently selected from at least one of methyl orthosilicate, ethyl orthosilicate, silica sol, solid silica gel, silica white, and sodium silicate;

the aluminum sources in step a) and step a0) are independently selected from at least one of sodium metaaluminate, alumina, aluminum hydroxide, aluminum isopropoxide, aluminum 2-butoxide, aluminum chloride, aluminum sulfate, and aluminum nitrate;

the alkali metal source in step a) and step a0) is independently selected from at least one of sodium hydroxide, potassium hydroxide and cesium hydroxide.

4. The method according to claim 1 or 2, wherein the organic templating agent R1 is selected from at least one quaternary ammonium compound having a formula represented by formula I:

in the formula I, R¹¹、R¹²、R¹³And R¹⁴Independently selected from C₁～C₁₂Alkyl of (C)₁～C₁₂Alkoxy group of (C)₁～C₁₂At least one of hydroxyalkyl groups of (a); x^n-Selected from OH^-、Cl^-、Br^-、I^-、NO₃ ^-、HSO₄ ^-、H₂PO₃ ^-、SO₄ ^2-、HPO₃ ^2-、PO₃ ^3-。

5. The method according to claim 1 or 2, wherein the organic templating agent R1 is selected from at least one of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide.

6. The method as claimed in claim 1 or 2, wherein the organic template R2 is at least one selected from quaternary ammonium compounds and nitrogen-containing heterocyclic compounds having a structural formula shown in formula II:

in the formula II, R²¹、R²²、R²³And R²⁴Independently selected from C₁～C₁₂Alkyl of (C)₁～C₁₂Alkoxy group of (C)₁～C₁₂At least one of hydroxyalkyl, aryl, phenylalkyl and adamantyl; x^n-Selected from OH^-、Cl^-、Br^-、I^-、NO₃ ^-、HSO₄ ^-、H₂PO₃ ^-、SO₄ ^2-、HPO₃ ^2-、PO₃ ^3-。

7. The method according to claim 6, wherein the nitrogen-containing heterocyclic compound is at least one selected from pyridine, piperidine, imidazole, piperazine, and derivatives thereof.

8. The process according to claim 1 or 2, wherein the organic templating agent R2 is selected from the group consisting of tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, tetrapentylammonium hydroxide, tetrahexylammonium hydroxide, tetrapropylammonium bromide, tetrabutylammonium chloride, tetrapentylammonium bromide, tripropylisobutylammonium bromide, tributylcyclohexylammonium hydroxide, dibutyldihexylammonium hydroxide, choline, triethylhydroxyethylammonium hydroxide, tripropylhydroxyethylammonium hydroxide, tributylhydroxyethylammonium hydroxide, tributylbenzylammonium hydroxide, triethylbenzylammonium hydroxide, tripropylbenzylammonium hydroxide, triethyladamantyl ammonium chloride, tripropyladamantyl ammonium chloride, pyridine, N-methylpyridine, N-ethylpyridine, N-propylpyridine, N-butylpyridine, 1-ethyl-3-butylpyridine hydroxide, N-ethylpyridine, N-propylpyridine, N-butylpyridine, N-ethylpyridine hydroxide, N-propylpyridinium bromide, N-butylpyridinium hydroxide, and mixtures thereof, 1-ethyl-2-propylpyridine hydroxide, piperidine, N-dimethylpiperidine, N-dimethyl-3, 5-diethylpiperidine hydroxide, N-dimethyl-3, 5-dipropylpiperidine hydroxide, N-diethyl-3, 5-dipropylpiperidine hydroxide, N-dimethyl-2, 6-dimethylpiperidine hydroxide, N-dimethyl-2, 6-diethylpiperidine hydroxide, imidazole, 1-ethyl-3-butylimidazole hydroxide, 1-ethyl-3-butyl-4-propylimidazole hydroxide, piperazine, N-methylpiperazine, 1, 4-dipropylpiperazine, 1-methyl-4-ethylpiperazine and 1-ethyl-4-butyl-5- At least one of methylpiperazines.

9. The method of claim 1, wherein the silicoaluminophosphate molecular sieve seeds having the FAU or EMT structure have a silicoaluminophosphate ratio of 2 or greater.

10. The method of claim 1, wherein the silicoaluminophosphate molecular sieve seed crystal having the FAU or EMT structure has a silicoaluminophosphate ratio of 2.5 to 200.

11. The method of claim 1, wherein the seeds of the silicoaluminophosphate molecular sieve having the structure of FAU or EMT are selected from Na, NH₄Type and HAt least one of zeolite molecular sieves.

12. The method as claimed in claim 2, wherein in step a0), the aluminum source, the silicon source, the alkali metal source, the organic template R1 and the water are mixed according to the following molar ratio:

1Al₂O₃:(10～30)SiO₂:(0～5)M₂O:(5～30)R1:(100～600)H₂O；

13. The method according to claim 2, wherein the aging temperature in step a0) is 25-120 ℃.

14. The method as claimed in claim 2, wherein in step a0), the aging time is 0.5-6 days.

15. The method according to claim 2, characterized in that in step a0), the aging is performed in a dynamic or static manner.

16. The method according to claim 2, characterized in that in step a0), the aging is performed in a combination of dynamic and static manner.

17. The method according to claim 1, wherein in step a), the guiding agent is added in an amount such that the SiO in the guiding agent₂In an amount of SiO in the initial gel₂3-20 wt% of the content.

18. The method according to claim 1, wherein in step a), the silicon having the FAU or EMT structureThe addition amount of the aluminum molecular sieve seed crystal is SiO in the initial gel₂3-20 wt% of the content.

19. The method according to claim 1, wherein the stirring is performed for 1 to 3 hours in step a).

20. The method of claim 1, wherein in step b), the synthetic gel is dewatered to H therein₂O and SiO₂The molar ratio of (a) to (b) is 1:1 to 3: 1.

21. The method according to claim 1, wherein in step b) the water removal is performed by evaporation by heating.

22. The method according to claim 21, wherein the temperature of the evaporation in step b) is 50-100 ℃.

23. The method according to claim 21, wherein in step b), the evaporation mode is static evaporation or stirring evaporation.

24. The method as claimed in claim 1, wherein the temperature of the crystallization in step c) is 90 to 180 ℃.

25. The method as claimed in claim 1, wherein the crystallization time in step c) is 0.1 to 10 days.

26. The process according to claim 1, wherein in step c) the crystallization is carried out in a dynamic or static manner.

27. The method according to claim 1, wherein in step c) the crystallization is performed in a combination of dynamic and static conditions.

28. The method of claim 1 or 2, wherein the high silicon Y molecular sieve has an anhydrous chemical composition according to formula III:

kM·mR1·nR2·(Si_xAl_y)O₂formula III

Wherein M is at least one selected from alkali metal elements;

29. The method of claim 28, wherein M is Na, K and/or Cs.

30. The method of claim 28, wherein k is 0.01 to 0.15; m is 0 or 0.01 to 0.1; n is 0.02 to 0.15.

31. The method of claim 28, wherein k is 0.02 to 0.13; m is 0 or 0.01 to 0.04; n is 0.03 to 0.08.