WO2011047528A1

WO2011047528A1 - Bi-microporous-mesoporous composite molecular sieve y-beta/ mcm-41 and preparing method thereof

Info

Publication number: WO2011047528A1
Application number: PCT/CN2010/001369
Authority: WO
Inventors: 王东青; 李全芝; 张志华; 田然; 孙发民; 李旭光; 于春梅; 戴宝琴; 赵野; 王甫村; 黄耀; 吕倩; 郭淑芝; 李海岩; 张庆武; 马守涛; 丛丽茹; 张全国; 邴淑秋
Original assignee: 中国石油天然气股份有限公司
Priority date: 2009-10-22
Filing date: 2010-09-07
Publication date: 2011-04-28
Also published as: CN102039200A; CN102039200B

Abstract

A bi-microporous-mesoporous composite molecular sieve Y-Beta/MCM-41 and preparing method thereof are provided. The molecular sieve is compounded with bi-microporous zeolites Y and Beta and molecular sieve MCM-41. The Y and Beta microporous phases are tightly wrapped by MCM-41 hexagonal mesoporous phase. The method includes: using hexadecyl trimethyl ammonium bromide cationic surfactant and polyethylene glycol octylphenyl ether nonionic surfactant as templates, respectively introducing pretreated bi-microprous phase and synthesized mesoporous inorganic silicon source into the system, adjusting the pH value of the system with inorganic acid, then treating with hydrothermal crystallization to obtain bi-microporous-mesoporous composite molecular sieve Y-Beta/MCM-41. The ratio of silica to alumina and the microporous phase content in the molecular sieve can be adjusted, and the molecular sieve can be used without ion exchange.

Description

Y-Beta/MCM-41 double microporous-mesoporous composite molecular sieve and preparation method thereof

Technical field

The invention relates to a novel catalytic material containing a double microporous phase of Y-type and Beta-type zeolite and a mesoporous phase of MCM-41 and a preparation method in an acidic system.

Background technique

The hydrocracking catalyst developed with molecular sieve materials as the carrier is the mainstream and direction of the development of hydrocracking technology. The molecular sieves currently used are mainly micro-porous zeolite molecular sieves such as Y-type and Beta-type, and the performance of micro-porous molecular sieves is improved. The aspect played an important role. However, as the oil is heavier, the narrow pore size of the microporous molecular sieve limits its application. Although the secondary treatment can be reamed by the ultra-stable secondary treatment, the pore diameter is not uniform. In 1992, a mesoporous molecular sieve appeared, its large specific surface area and uniform mesoporous pore size, which brought light to heavy oil and macromolecular reactions. However, the weak acidity and low hydrothermal stability caused by the disorder of the pore wall hinder its promotion and application. The appearance of microporous-mesoporous composite molecular sieve materials not only improves the effective pore size distribution of microporous materials, but also solves the problem of low acid strength of mesoporous materials, and makes the leap-forward progress of the catalytic performance of hydrotreating catalysts possible.

Therefore, research on composite molecular sieves has been conducted in recent years. Scientists use a variety of methods to synthesize composite molecular sieves. However, most of these composite molecular sieves are synthesized under alkaline conditions. We intend to synthesize Y-Beta/MCM-41 double microporous mesoporous composite molecular sieves in an acidic system by hydrothermal epitaxial growth. The treatment catalyst provides an alternative new carrier material to meet the needs of producing different oils.

The key of the invention is how to make the mesoporous molecular sieve epitaxial growth on the microporous molecular sieve in the acidic system, which involves the hexagonal mesoporous phase in the Y-Beta/MCM-41 double microporous mesoporous in the acidic system. Synthesis. Acidic system is different from alkaline system using cationic surfactant S+ and inorganic species

组装 The assembly route of s+r, here is the assembly route of s+s^xf. The synthesis of hexagonal mesoporous molecular sieves in the acidic system mostly uses a single cationic surfactant cetyltrimethyl quaternary ammonium salt and an expensive organosilicon source of tetraethyl orthosilicate. Journal of Inorganic Chemistry, 2001, 17 (2): 249~ 255). Qi limin et al. used the binary mixed surfactant CTAB and the fatty alcohol polyoxyethylene ether C ₁₆ E0 _1Q as a template, but still used expensive tetraethyl orthosilicate as the silicon source (Chem Mater, 1998, 10: 1623~1626). ). These reported work not only employ expensive silicon sources, but the synthetic hexagonal mesoporous molecular sieves are poorly ordered. Therefore, it is difficult to synthesize hexagonal mesoporous molecular sieves in acidic systems. It is more difficult to synthesize Y-Beta/MCM-41 double microporous mesoporous composite molecular sieves. We used a binary mixed surfactant to assemble the mesoporous phase and the microporous phase using the s+s°x_r route, ie, the cationic surfactant CTAB and the nonionic surfactant OP-10 were used as template to the synthesis system. Introducing the pretreated double microporous phase and the inorganic silicon source and aluminum source for synthesizing the mesoporous phase, respectively, and adjusting the pH of the system with a mineral acid containing X·(N0 ³ - ₅ C1-, S0 ₄ ² -) Acidity is required. Then, the Y-Beta/MCM-41 double microporous mesoporous composite molecular sieve with double microporous phase silicon-aluminum ratio and adjustable microporous and mesoporous content can be obtained by hydrothermal crystallization treatment. The invention is a further development of a composite molecular sieve catalytic material, and the synthesized double microporous-mesoporous composite molecular sieve catalytic material and a preparation method thereof have not been reported. The research route of synthesizing microporous-mesoporous composite molecular sieve in acidic system can not only improve the acid strength in the product, but also improve the catalytic reaction activity, and can directly obtain the hydrogen type product, and can be directly used without proton exchange, which simplifies production. The program facilitates industrial production, and the use of binary mixed templating agents can also reduce costs and develop value. The invention has the advantages of simple operation, good reproducibility, economy and environmental protection. Synthetic Y-Beta/MCM-41 double microporous-mesoporous composite molecular sieve material can fully utilize mesoporous material pores Large and uniform diameter and the advantages of Y-type and Beta-type zeolites can be used as a new carrier for hydrocracking catalysts, and can be used as a new type of hydrocracking catalyst with independent intellectual property rights. It also has potential application value in other fields such as petrochemical industry. .

Summary of the invention

The object of the present invention is to provide a novel catalyst carrier material which is synthesized from a double microporous phase Y-type and Beta-type zeolite and MCM-41 mesoporous phase in an acidic system, and has simple operation, good reproducibility and economy. , environmentally friendly preparation methods.

The novel Y-Beta/MCM-41 double microporous-mesoporous composite molecular sieve prepared by the invention adopts a pretreated microporous phase, a silicon source and an aluminum source as an inorganic precursor (1+) in an acidic system, in a cation (s+) - Under the action of a non-ionic (s ^Q ) mixed surfactant, supramolecular self-assembly is carried out through the s ⁺ s°x' route to achieve epitaxial phase epitaxial growth on the microporous phase. The preparation steps are as follows:

(1) Microporous phase pretreatment: Take a certain amount of Y-type and Beta-type zeolite, mix them in a certain proportion, add them to deionized water, stir evenly at a certain temperature, and record them as solution A for use.

(2) taking a certain amount of surfactant, hexadecanyltrimethylammonium bromide (CTAB), polyethylene glycol octyl phenyl ether (OP-10) and a small amount of inorganic acid, and adding it to deionized water. Stir at room temperature for a period of time. After the solution is clarified, it is recorded as solution B for use.

(3) Adding the obtained solution A to the solution B, stirring uniformly at room temperature, then slowly adding a silicon source to the mixed solution, and continuing to stir at room temperature, after the components in the mixed solution are uniformly stabilized, using inorganic The acid or base adjusts the pH of the system, and then stirs at a constant speed. After the system is stabilized, the obtained glue is charged into a stainless steel reaction vessel with a liner, and hydrothermally crystallized at a specific temperature. (4) The crystallized product obtained in (3) is subjected to suction filtration, washing, and drying to obtain a white solid powder. The solid powder is first calcined in a nitrogen stream at a specific temperature for a certain period of time, and then transferred to a muffle furnace and further calcined at a specific temperature for a while in an air atmosphere to obtain a Y-Beta/MCM-41 pair. Microporous-mesoporous composite molecular sieves.

Raw material ratio molar ratio: CTAB/SiO ₂ = 0.25~0.30, CTAB/OP-10=6~8, SiO ₂ /H ₂ O=160~170, HT/S^l.98; by mass ratio (Y +Beta) /Si0 ₂ is 0.30~0.80, and the amount of microporous phase Y type and Beta type zeolite can be adjusted at any ratio;

The microporous phase has a pretreatment temperature of 30 ° C to 50 ° C and a treatment time of 25 mii! ~ 45min; the pH of the synthetic system is in the range of 1.0~2.0;

The crystallization temperature is 100 ° C, and the crystallization time is 48 h to 72 h;

The crystallization product is calcined in a nitrogen stream at a calcination temperature of 500 ° C to 550 ° C and a calcination time of 1 h to 2 h; the calcination temperature in the air is 500 ° C to 600 ° C, and the calcination time is 5 h to 6 h.

The silicon source used in the present invention may be any one or a mixture of two of sodium silicate, white carbon black, and tetraethyl orthosilicate.

The inorganic acid used in the present invention may be any one or a mixture of two of hydrochloric acid, sulfuric acid and nitric acid; and the inorganic base is any one of sodium hydroxide or potassium hydroxide.

In the present invention, the surfactant solution is stirred for 5 minutes to 10 minutes, and then the inorganic acid is preferably added. The stirring time before adjusting the pH value of the system is lh~2h, and the stirring time after adjusting the pH value is 0.5h~1.5h.

The Y-Beta/MCM-41 double microporous-mesoporous composite molecular sieve prepared by the invention is characterized by using an inorganic silicon source, using supramolecular self-assembly of mixed surfactants CTAB and OP-10, through S ⁺ S ^G The X'I+ route is obtained by hydrothermal crystallization. The novel Y-Beta/MCM-41 double microporous-mesoporous composite molecular sieve synthesized by the invention has the following characteristics:

(1) From the microscopic morphology, the composite molecular sieve exhibits an inclusion structure in which the microporous phase is closely covered by the mesoporous phase, which is significantly different from the mechanical mixture.

(2) The Y-Beta/MCM-41 double microporous mesoporous composite molecular sieve synthesized in the acidic system has a specific surface area of 935.66 m ² /g and a pore volume of 0.877 cm ³ /g (where the micropore volume is 0.131 cm ³ / g), the average pore diameter is 3.75 nm (where the pore size of mesoporous MCM-41 is 2.66 nm), the pore wall thickness is 1.59 nm, the ratio of micropores to mesopores is 7% to 35%, and the proportion of microporous phase Y and Beta zeolites is It can be adjusted arbitrarily, and the silicon to aluminum ratios of the two are 4.0 to 6.0 and 13.0 to 90.0, respectively.

(3) The synthesized Y-Beta/MCM-41 double microporous mesoporous composite molecular sieve can be directly used as an acidic molecular sieve material without ion exchange.

The Y-Beta/MCM-41 double microporous-mesoporous composite molecular sieve proposed by the invention is a novel catalytic material, and its structure and mechanical mixture are substantially different. The microporous phase and the microporous phase in the composite have a synergistic effect between the microporous phase and the mesoporous phase, so that it has good catalytic reaction performance. The catalytic reaction of the probe molecule a-methylnaphthalene showed that the conversion of a-methylnaphthalene was significantly higher than that of the mechanical mixtures of ¥, Beta and MCM-41, and the ring-opening ability, dealkylation ability and The compositional ability is better than that of the mechanical mixture, so the new double microporous-mesoporous composite molecular sieve has great potential industrial application value.

DRAWINGS

Figure la ΜΥβ-l XRD spectrum

X RD spectrum of Figure lb ΜΥβ-l

Figure 2 Νβ-l low temperature Ν ₂ adsorption-desorption isotherm and pore volume obtained by BJH desorption Relationship with hole size (inset)

Figure 3a Scanning electron micrograph of ΜΥβ-l

Figure 3b Scanning electron micrograph of ΜΥβ-l

Figure 4a Comparison of catalytic cracking properties of probe molecules a-methylnaphthalene with mechanical mixtures of ΜΥβ-l and Y, Beta and MCM-41

Figure 4b Comparison of the catalytic cracking properties of probe molecules α-methylnaphthalene by a mixture of ΜΥβ-l and Y, Beta and MCM-41 and mechanical mixtures

detailed description

The embodiments of the present invention are further described below by way of examples, but the invention is not limited to the embodiments.

Example 1

Each of 0.36 g of Y type and 0.36 g of Beta type zeolite powder was mixed and pretreated, and then added to a mixed solution containing CTAB, OP-10 and HCl, stirred at room temperature for 30 minutes, and then a sodium silicate solution was slowly added dropwise to the mixture. The molar composition of the starting material was lSi0 ₂ : 0.28 CTAB: 0.04OP-10: (Y+Beta): 1.98HC1: 165H ₂ 0, where (Y+Beta) /Si0 ₂ (mass ratio) = 0.594. After stirring for 1 h, the pH of the system was adjusted to 1.0, and after stirring for 30 min, the glue was placed in a lined reactor and crystallized at 100 ° C for 48 h. The product was filtered, washed, dried and calcined to obtain an acidic system. The synthetic micropores were compared with a 1:1, relative content of 59.4% Y-Beta/MCM-41 double microporous mesoporous composite molecular sieve. This sample was named ΜΥβ-1.

Example 2

0.48g of Y type and 0.24g of Beta zeolite powder were mixed and pretreated, added to a mixed solution containing CTAB, OP-10 and HCl, stirred at room temperature for 30 min, and then mixed to the mixture. The sodium silicate solution was slowly added dropwise. The molar composition of the starting material was lSi0 ₂ : 0.28 CTAB: 0.04OP-10: (Y+Beta): 1.98HC1: 165H ₂ 0, where Y+Beta) /Si0 ₂ (mass ratio) = 0.794. After stirring for 1 h, the pH of the system was adjusted to 1.8, and after stirring for 30 min, the glue was placed in a lined reactor and crystallized at 100 ° C for 48 h. The product was filtered, washed, dried and calcined to obtain an acidic system. The synthesized feed micropores were compared with Y:Beta/MCM-41 double microporous mesoporous composite molecular sieves with a relative content of 29.4 and a relative content of 79.4%. This sample was named as ΜΥβ-2.

It can be seen from the XRD spectrum of ΜΥβ-2 in Fig. 1. In the low-angle diffraction region (left of Fig. 1), a strong [100] diffraction peak corresponding to the hexagonal mesoporous phase is observed, and mesopores can also be observed. The [110] and [200] diffraction peaks of the internal fine structure. The diffraction peaks of the Υ and Beta microporous phases were clearly observed in the high-angle diffraction region (Fig. 1 right), indicating that the microporous phase was not completely destroyed in the system.

From Fig. 2, the low temperature Ν ₂ adsorption-desorption isotherm of ΜΥβ-2 and the relationship between pore volume and pore size obtained by desorption of BJH (inset), it can be seen that due to the introduction of mesoporous phase, ΜΥβ-1 is > The 1⁄2 adsorption desorption isotherm showed a significant jump in the region of relative pressure P/P _Q of 0.3~0.4. It has been determined that the ΜΥβ-l specific surface area is 935.66 m ² /g, the pore volume is 0.877 cm ³ /g (the pore volume is 0.131 cm ³ /g), and the average pore diameter is 3.75 nm (where the pore diameter of mesoporous MCM-41 is 2.66 nm). ), the wall thickness is about 1.59 nm.

Figure 3 is a scanning electron micrograph of ΜΥβ-2 with different magnifications. It can be seen that ΜΥβ-1 exhibits a morphology in which small MCM-41 particles envelop two aggregates of microporous zeolite particles.

Figure 4 is a comparison of the catalytic cracking performance of the probe molecule α-methylnaphthalene by a mechanical mixture of ΜΥβ-2 and Y, Beta and MCM-41. It can be seen that the conversion of α-methylnaphthalene is significantly higher than that of Y, Beta and MCM-41, and the ring opening ability, depurination ability and isomerization ability are superior to those of the mechanical mixture. Example 3

0.54 g of the Y form and 0.18 g of the Beta type zeolite powder were mixed and pretreated, added to a mixed solution containing CTAB, OP-10 and HCl, stirred at room temperature for 30 min, and then a sodium silicate solution was slowly added dropwise to the mixed solution. The molar composition of the starting material was lSi0 ₂ : 0.28 CTAB: 0.04OP-10: (Y+Beta): 1.98HC1: 165H ₂ 0, where Y+Beta) /Si0 ₂ (mass ratio) = 0.794. After stirring for 1 h, the pH of the system was adjusted to 2.0, and then the mixture was further stirred for 30 min. The glue was placed in a lined reactor and crystallized at 100 ° C for 72 h. The product was filtered, washed, dried, and calcined to obtain acidity. Compared with the feed micropores of the system synthesis, the Y-Beta/MCM-41 double microporous mesoporous composite molecular sieves with a relative content of 3:1 and a relative content of 79.4%. This sample was named ΜΥβ-3.

Example 4

Each of 0.45 g of Y type and 0.09 g of Beta type zeolite powder was mixed and pretreated, and then added to a mixed solution containing CTAB, OP-10 and HCl, and stirred at room temperature for 30 minutes, and then a sodium silicate solution was slowly added dropwise to the mixture. The molar composition of the starting material was lSi0 ₂ : 0.28 CTAB: 0.04OP-10: (Y+Beta): 1.98HC1: 165H ₂ 0, where (Y+Beta) /Si0 ₂ (mass ratio) = 0.594. After stirring for lh, the pH of the system was adjusted to 1.5, and after stirring for another 30 minutes, the glue was placed in a lined reactor and crystallized at 100 ° for 48 hours. The product was filtered, washed, dried and calcined to obtain an acidic system. The microporous ratio is 5:1, and the relative content of 59.4% is Y-Beta/MCM-41 double microporous mesoporous composite molecular sieve. This sample was named ΜΥβ-4.

Industrial applicability

From the acid data of Table 4 ΜΥβ- ΜΥβ-2, ΜΥβ-3 and ΜΥβ-4, it can be seen that the Y-Beta/MCM-41 double microporous-mesoporous composite molecular sieve synthesized by the acidic system is more acidic, 150 °C off The total acid amount in the time is greater than 0.3mmol/g, and the total acid amount at 300 °C is greater than that at 300 °C. 0.2mmol/g, which explains the strong catalytic cracking performance of α-methylnaphthalene on this kind of composite molecular sieve. Table 1 Acidic data of ΜΥβ-1, ΜΥβ-2, ΜΥβ-3 and ΜΥβ-4

150 ° C, mmol / g 300 ° C, mmol / g sample

Niobic acid L acid Total acid B acid L acid Total acid

ΜΥβ-1 0.112 0.225 0.337 0.072 0.142 0214

ΜΥβ-2 0.147 0.252 0.399 0.104 0.182 0.286

ΜΥβ-3 0.152 0.230 0.382 0.113 0.160 0.273

ΜΥβ-4 0.161 0.219 0.380 0.124 0.140 0.264 The novel Y-Beta/MCM-41 double microporous mesoporous composite molecular sieve synthesized by the invention has the following characteristics:

(1) From the microscopic morphology, the composite molecular sieve exhibits an inclusion structure in which the microporous phase is tightly covered by the mesoporous phase, which is significantly different from the mechanical mixture.

(3) The synthesized Y-Beta/MCM-41 double microporous-mesoporous composite molecular sieve can be directly used as an acidic molecular sieve material without ion exchange. The Y-Beta/MCM-41 double microporous-mesoporous composite molecular sieve proposed by the invention is a novel catalytic material, and its structure and the mechanical mixture are substantially different. Microporous phase and micro in composite A synergistic effect occurs between the pore phases, the microporous phase and the mesoporous phase, so that it has a good catalytic reaction performance. The catalytic reaction of the probe molecule a-methylnaphthalene showed that the conversion of α-methylnaphthalene was significantly higher than that of the mechanical mixtures of ¥, Beta and MCM-41, and the ring-opening ability, the debonding ability and the difference The compositional ability is better than that of the mechanical mixture, so the new double microporous-mesoporous composite molecular sieve has great potential industrial application value.

Claims

Rights request

1. A Y-Beta/MCM-41 double microporous-mesoporous composite molecular sieve characterized by: a composite of Y-type and Beta-type double-microporous zeolite and MCM-41 molecular sieve, MCM-41 hexagonal mesoporous phase Closely wrapped Y-type and Beta-type microporous phases.

The Y-Beta/MCM-41 double microporous-mesoporous composite molecular sieve according to claim 1, wherein the double microporous mesoporous composite molecular sieve has a specific surface area of 935.66 m ² /g and a pore volume of 0.877 cm. ³ / g, wherein the micropore volume is 0.131 cm ³ /g, and the average pore diameter is 3.75 nm. The pore diameter of mesoporous MCM-41 is 2.66 nm, the pore wall thickness is 1.59 nm, and the ratio of micropores to mesopores is 7 to 35 %. The ratio of the pore phase Y type and Beta type zeolite can be arbitrarily adjusted, and the silicon to aluminum ratios of the two are 4.0 to 6.0 and 13.0 to 90.0, respectively.

The method for preparing a Y-Beta/MCM-41 double microporous-mesoporous composite molecular sieve according to claim 1, wherein:

(1) Microporous phase pretreatment: Take a certain amount of Y-type and Beta-type zeolite, mix them in proportion and add to deionized water, stir evenly at a specific temperature, and record as solution A for use;

(2) Take a certain amount of surfactant, hexadecanoyltrimethylammonium bromide, polyethylene glycol octyl phenyl ether, and a small amount of inorganic acid, then add to deionized water and stir at room temperature for a while. After the solution is clarified, it is recorded as solution B for use;

(3) Adding the obtained solution A to the solution B, stirring uniformly at room temperature, then slowly adding a silicon source to the mixed solution, and continuing to stir at room temperature, after the components in the mixed solution are uniformly stabilized, using inorganic Acid or alkali to adjust the pH of the system, then stir evenly, wait for the system After stabilization, the obtained glue liquid is charged into a stainless steel reaction vessel with a liner for hydrothermal crystallization treatment;

(4) The crystallization product obtained in (3) is subjected to suction filtration, washing, and drying to obtain a white solid powder, which is first calcined in a nitrogen stream for a while, and then transferred to a muffle furnace in an air atmosphere. After continuing to roast for a while, a Y-Beta/MCM-41 double microporous-mesoporous composite molecular sieve is obtained;

Raw material ratio molar ratio: CTAB/SiO ₂ = 0.25~0.30, CTAB/OP-10=6~8, SiO ₂ /H ₂ O=160~170, HVSiOfl.98; by mass ratio (Y+Beta) / Si0 ₂ is 0·30~0.80, and the amount of microporous phase B type and Beta type zeolite can be adjusted at any ratio;

The pretreatment temperature of the microporous phase is 30° (~ 50 ° C, the treatment time is 25 min to 45 min; the pH of the synthetic system is in the range of 1.0 to 2.0;

The crystallization temperature is 100 ° C, and the crystallization time is 48 h to 72 h _;

The crystallization product is calcined in a nitrogen stream, and the calcination temperature is 500 ° C to 550 ° C, and the calcination time is lh to 2 h; the calcination temperature in the air is 500 ° C to 600 ° C, and the calcination time is 51! ~ 6h.

The method for preparing a Y-Beta/MCM-41 double microporous-mesoporous composite molecular sieve according to claim 3, wherein the inorganic acid used may be any one or two of hydrochloric acid, sulfuric acid and nitric acid. a mixture; the inorganic base is any one of sodium hydroxide or potassium hydroxide.

The method for preparing a Y-Beta/MCM-41 double microporous-mesoporous composite molecular sieve according to claim 3, wherein the silicon source is sodium silicate, white carbon black or ethyl orthosilicate. Any one or a mixture of two.

The method for preparing a Y-Beta/MCM-41 double microporous-mesoporous composite molecular sieve according to claim 3, wherein: the surfactant solution is stirred at 5 mir! ~ lOmin after adding inorganic Acid, the mixing time before adjusting the pH of the system is generally 11! ~ 2h, the mixing time after adjusting the pH is 0.51! ~ 1.5h.