CN100390058C - A kind of synthetic method of ZSM-5 and MAPO-5 double structure molecular sieve - Google Patents

Abstract

The invention relates to a method for synthesizing ZSM-5 and MAPO-5 double-structured molecular sieves. It mainly takes a heteroatom source M, aluminum source, phosphorus source, template agent, ZSM-5 and deionized water as raw materials, The proportion relationship of each raw material in terms of moles is: M _x O _y : Al ₂ O ₃ : _{P 2} O ₅ : R: _{H 2} O = 0.5～1.5: 5～15: 4～20: 4～20: 100～2000; Wherein: X and Y represent the number of atoms of the heteroatom source M and O atoms respectively; R represents the templating agent; ZSM-5 is the original powder of ZSM-5, ZSM-5 and the above-mentioned mixture are connected in any proportion, and the raw materials are mixed in 10 Mix and stir evenly at ℃～95℃, then undergo aging and aging, hydrothermal crystallization at a constant temperature of 20℃～200℃ for 5～200 hours, recover the product obtained after crystallization, filter, wash, exchange, Drying and roasting can obtain the finished catalyst. In the molecular sieve synthesized by the method of the present invention, MAPO-5 is more evenly distributed on the surface of ZSM-5, and has potential application value for heavy oil catalytic cracking, catalytic cracking, hydrocracking and other fine chemical fields.

Description

A kind of synthetic method of ZSM-5 and MAPO-5 double structure molecular sieve

1. Technical field:

The invention relates to a method for synthesizing double-structure molecular sieves, more specifically to a method for synthesizing ZSM-5 and MAPO-5 double-structure molecular sieves.

2. Background technology:

Fluid catalytic cracking (FCC) is one of the most important processes in the oil refining industry. The simple catalyst formulation currently used in this process is difficult to meet the increasing requirements of commercial and environmental protection. A key factor to improve the conversion depth of heavy oil catalytic cracking and the yield of light oil is that the catalyst should have a suitable pore distribution and acidity distribution. , the catalytic material is required to provide heavy oil molecules with a "relay" catalytic cracking pore structure from large to small. Therefore, researching and synthesizing molecular sieve materials with certain pore size and acidity distribution is the goal pursued by scientists in this field.

ZSM-5 zeolite is a shape-selective molecular sieve invented by Mobil Corporation of the United States. ZSM-5 has a relatively high silicon-aluminum ratio, and its skeleton is mainly composed of five-membered rings, so it has high heat resistance and thermal stability. In addition, because the pores cross each other, it is beneficial to prevent clogging, and the diameter is not large, so it is particularly beneficial to shape-selective catalysis. In the early 1980s, ZSM-5 zeolite began to be used in catalytic cracking catalysts to increase the octane number of gasoline. However, due to its small pore size (<0.8nm), it is difficult for large-diameter molecules to enter the pores. The macromolecules formed in the channel cannot escape quickly, which often leads to side reactions, which greatly reduces its application range.

When two or more molecular sieves are compounded together through a synthetic method, they can exhibit good synergy and excellent catalytic performance. Patents USP5888921 and CN1524617A respectively report a synthetic ZSM-5/AlPO ₄ -5 double-structure molecular sieve. However, as a part of the molecular sieve, the skeleton of AlPO ₄ -5 is composed of AlO ₄ and PO ₄ , the whole skeleton is electrically neutral, there are no exchangeable cations, the surface acidity is very weak, and the activity for catalytic cracking of heavy oil is not very high . Introduce one or more heteroatoms into the framework to carry out isomorphic substitution of Al atoms and P atoms in the framework of AlPO ₄ -5 molecular sieve, realize the modulation and modification of its structure, and increase the negative charge of the molecular sieve framework. It is conducive to the formation of B acid sites, so its acidity is stronger than that of AlPO ₄ -5. In recent years, many new technologies for the synthesis of heteroatom aluminum phosphorus molecular sieves have emerged. Patents EP83109860 and USP4440871 reported that silicon was used to replace part of the aluminum and phosphorus in the framework, and a new silicon-phosphorus-aluminum molecular sieve (SAPO) was synthesized. Patent CN1268485A reports a new zirconium-boron-phosphorus-aluminum molecular sieve compound synthesized by using zirconium and boron as heteroatoms, but its reaction selectivity is low and its activity is poor.

3. Contents of the invention:

1, purpose of the invention: the present invention provides a kind of synthetic method of ZSM-5 and MAPO-5 double structure molecular sieve, its purpose is to solve the existing technology of preparing the catalyzer that is used in the fluidized catalytic cracking process of oil refining industry, obtained Catalysts have problems such as low reaction selectivity and poor activity.

A method for synthesizing a ZSM-5 and MAPO-5 double-structure molecular sieve, characterized in that: the double-structure molecular sieve is used as a catalyst in heavy oil catalytic cracking by weighing a heteroatom source M, an aluminum source, and a phosphorus source , template agent, ZSM-5 and deionized water as raw materials, the ratio of each raw material in terms of moles is: M _x O _y : Al ₂ O ₃ : P ₂ O ₅ : R: _{H 2} O = 0.5～1.5: 5～ 15: 4～20: 4～20: 100～2000; among them: X, Y represent the number of atoms of heteroatom source M and O atoms; R represents the template agent; ZSM-5 is the original powder of ZSM-5, ZSM- 5 and the above-mentioned mixture in any proportion, mix and stir the raw materials at 10°C to 95°C, and then undergo aging and aging, and crystallize at a constant temperature of 20°C to 200°C for 5 to 200 hours, and crystallize The product obtained after catalysis is recovered, and the catalyst product is obtained through filtration, washing, exchange, drying, and roasting; the template R is selected from one or both of triethylamine and tri-n-propylamine; the hetero The atomic source M is a zirconium source, and the zirconium source is selected from one of zirconium oxide, zirconyl chloride, zirconyl nitrate, zirconium sulfate, zirconium ethoxide, zirconium propoxide, zirconium formate, and zirconium acetate.

The phosphorus source is phosphoric acid.

The aluminum source is an inorganic aluminum source or an organic aluminum source.

The inorganic aluminum source is selected from sodium metaaluminate, aluminum chloride or pseudo-boehmite; the organic aluminum source is aluminum isopropoxide.

The ZSM-5 is the original powder of ZSM-5. Before synthesizing the catalyst, the original powder of ZSM-5 and water are mixed in any proportion, and stirred evenly for later use.

The aging process is aging at a temperature of 30°C to 60°C for 30 minutes to 5 hours; the aging process is aging at a temperature of 24°C to 40°C for 30 minutes to 60 hours. The temperature varies, and the time is short when the temperature is high; the filtering and washing process is 1 to 4 times; the washing process is washed with deionized water; ~6 hours; the hydrothermal crystallization process is hydrothermal crystallization at 20°C to 200°C for 5 to 200 hours; the exchange process is at 20°C to 95°C with a concentration of 1% to 20% The NH ₄ NO ₃ aqueous solution is exchanged for 1 to 24 hours; the roasting process is to roast at 500° C. to 650° C. for 2 to 7 hours.

3. Advantages and effects: Through the implementation of the technical solution of the present invention, the existing technology for preparing catalysts used in the fluidized catalytic cracking process of the oil refining industry can be well solved, and the prepared catalysts have low reaction selectivity and poor activity. question. The method of the present invention has synthesized a kind of ZSM-5 (core)/MAPO-5 (shell) type double-structure molecular sieve, and it is that a kind of inner core has the acidity and channel characteristic of ZSM-5, and outer layer has the acidity and pore characteristics of MAPO-5 Molecular sieve with channel characteristics. The inner core of the double-structure molecular sieve has a zeolite structure of silicon and aluminum molecular sieves, and the outer layer is a new three-dimensional structure composed of AlO ₄ , PO ₄ and MO ₄ tetrahedrons. This double-structure molecular sieve As a catalytic material, the different advantages of core and shell molecular sieves can be used to facilitate the catalytic reaction. In the catalytic cracking of heavy oil, larger molecules can be cracked in the shell layer (MAPO-5) first, and then Smaller molecules re-enter the inner core, and undergo further cracking nuclear isomerization on ZSM-5, which effectively optimizes the catalyst pore distribution and acidity distribution, and has a certain potential application value in the catalytic cracking of heavy oil.

Fourth, the specific implementation method:

The content of the present invention will be described in further detail below by way of examples, but the present invention is not limited thereto.

MAPO-5 of the present invention represents phosphorus-aluminum heteroatom molecular sieves, and the water used in the following examples is deionized water; the reagents used are all analytically pure reagents unless otherwise specified; in the examples, the finished product The X-ray diffraction measurement is made by Japan Rigaku D/MAX rA X-ray diffractometer, the test conditions are: X-ray CuKα target radiation, graphite monochromator, tube voltage 40KV, tube current 80mA, rate wave plate is Ni, scan rate is 6°/min, the step width is 0.20°.

Example 1:

Weigh 1.1 grams of zirconia and 105 grams of deionized water and mix them in a constant temperature water bath at 45 ° C. After stirring and dissolving completely, add 13.2 grams of pseudoboehmite with a water content of 27% and stir for a certain period of time, then add 14 ml of phosphoric acid drop by drop. After stirring, add 14ml of triethylamine dropwise, then mix with the mixture of 20g of ZSM-5 and 35g of water prepared in advance, age at 30°C for 5 hours, and then at 40°C for 30 A gel was obtained after 10 minutes of aging;

Put the above gel into a white steel tank lined with a polytetrafluoroethylene inner membrane, heat crystallization at 130°C for 48 hours, and recover the product. Exchange with 7% NH ₄ NO ₃ aqueous solution for 5 hours, then filter and wash several times, dry at 105°C for 2 hours, and then bake at 590°C for 3 hours to obtain the finished product. For the X-ray powder diffraction data of the obtained product, see Schedule 1.

Example 2:

Weigh 1.4 grams of zirconia and 110 grams of deionized water and mix them in a constant temperature water bath at 33 ° C. After stirring and dissolving completely, add 13.8 grams of pseudo-boehmite with a water content of 27%. After a certain period of time, add 15 ml of phosphoric acid dropwise and stir for several times. Add 15ml triethylamine dropwise after 1 hour, then mix with the mixture of 35g ZSM-5 and 40g water prepared in advance, age at 60°C for 30 minutes, then pass through 58°C at 24°C A gel was obtained after 1 hour of aging;

Put the above gel into a white steel tank lined with a polytetrafluoroethylene inner membrane, heat crystallization at a constant temperature of 145°C for 72 hours, and recover the product. Exchange with 8% NH ₄ NO ₃ aqueous solution for 6 hours, then filter and wash several times, dry at 110°C for 2 hours, and then bake at 580°C for 4 hours to obtain the finished product. The X-ray powder diffraction data of the resulting finished product has the characteristics of Table 1.

Example 3:

Weigh 1.0 g of zirconium sulfate and mix it with 100 g of deionized water, stir in a constant temperature water bath at 53°C to dissolve completely, add 11 g of pseudoboehmite with a water content of 27%, add 13 ml of phosphoric acid dropwise after a certain period of time, and stir After a few hours, add 13ml triethylamine drop by drop, stir well, then add and mix with the mixture of 25g ZSM-5 and 35g water prepared in advance, age at 45°C for 2.5 hours, and then The gel was obtained after 28 hours of aging under the condition of ℃;

Put the above gel into a white steel tank lined with a polytetrafluoroethylene inner membrane, heat crystallization at 130°C for 72 hours, and recover the product. Exchange with 10% NH ₄ NO ₃ aqueous solution for 6 hours, then filter and wash several times, dry at 106°C for 3 hours, and then bake at 576°C for 4 hours to obtain the finished product. The X-ray powder diffraction data of the resulting finished product has the characteristics of Table 1.

Example 4:

Weigh 1.2 grams of zirconium sulfate and 108 grams of deionized water, stir and dissolve completely in a constant temperature water bath at 82°C, add 13.5 grams of pseudoboehmite with a water content of 27%, then add 15ml of phosphoric acid drop by drop, stir well before adding 14ml triethylamine. Then mix with the mixture of 35 grams of ZSM-5 and 40 grams of water prepared in advance, and then age and age for a certain period of time. The aging and aging time varies with temperature, and the time for high temperature is short;

Put the above gel into a white steel tank lined with a polytetrafluoroethylene inner membrane, heat crystallization at 150°C for 72 hours, and recover the product. Exchange with 8% NH ₄ NO ₃ aqueous solution for 8 hours, then filter and wash several times, dry at 110°C for 2 hours, and then bake at 650°C for 3 hours to obtain the finished product. The X-ray powder diffraction data of the resulting finished product has the characteristics of Table 1.

Example 5:

Weigh 1.0 g of zirconia and 108 g of deionized water, stir and dissolve completely in a constant temperature water bath at 40°C, add 11.5 g of pseudo-boehmite with a water content of 27%, then add 14 ml of phosphoric acid drop by drop, stir well and then gradually Add 14ml of tri-n-propylamine dropwise, mix evenly with the mixture of 20 grams of ZSM-5 and 30 grams of water prepared in advance after a certain period of time, and then age and age for a certain period of time. The aging and aging time varies with temperature. short;

Put the above gel into a white steel tank lined with a polytetrafluoroethylene inner membrane, heat crystallization at a constant temperature of 185°C for 24 hours, and recover the product. Exchange with 4% NH ₄ NO ₃ aqueous solution for 8 hours, then filter and wash several times, dry at 110°C for 3 hours, and then bake at 630°C for 3 hours to obtain the finished product. The X-ray powder diffraction data of the resulting finished product has the characteristics of Table 1.

Embodiment 6:

Weigh 1.7 grams of zirconium sulfate and 130 grams of deionized water, stir and dissolve completely in a constant temperature water bath at 43°C, then add 15 grams of pseudoboehmite with a water content of 27%, then add 20ml of phosphoric acid drop by drop, stir thoroughly and then Add 20ml of tri-n-propylamine dropwise, and mix with the mixture of 40g of ZSM-5 and 50g of water prepared in advance. Re-aging and aging for a certain period of time, the aging and aging time varies with temperature, and the temperature is high and the time is short;

Put the above gel into a white steel tank lined with a polytetrafluoroethylene inner membrane, heat crystallization at a constant temperature of 85°C for 100 hours, and recover the product. Exchange with 14% NH ₄ NO ₃ aqueous solution for 6 hours; after several times of filtration and washing, dry at 100°C for 4 hours, and then bake at 600°C for 5 hours to obtain the finished product. The X-ray powder diffraction data of the resulting finished product has the characteristics of Table 1.

Embodiment 7:

Weigh 1.7 grams of zirconyl chloride and 125 grams of deionized water, stir and dissolve completely in a constant temperature water bath at 30°C, then add 11.8 grams of pseudo-boehmite with a water content of 27%, then add 11ml of phosphoric acid drop by drop, and stir well Then 12ml of tri-n-propylamine was added dropwise. Then mix with the mixture of 26 grams of ZSM-5 and 40 grams of water prepared in advance. Re-aging and aging for a certain period of time, the aging and aging time varies with temperature, and the temperature is high and the time is short;

Put the above gel into a white steel tank lined with a polytetrafluoroethylene inner membrane, heat crystallization at a constant temperature of 125°C for 90 hours, and recover the product. Exchange with 1% NH ₄ NO ₃ aqueous solution for 4 hours; then filter and wash several times, dry at 103°C for 2 hours, and then bake at 550°C for 6 hours to obtain the finished product. The X-ray powder diffraction data of the resulting finished product has the characteristics of Table 1.

Embodiment 8:

Weigh 0.8 grams of zirconyl nitrate and 70 grams of deionized water, stir and dissolve completely in a constant temperature water bath at 90°C, then add 13.5 grams of pseudoboehmite with a water content of 27%, stir for a certain period of time, and then add 10ml of phosphoric acid dropwise After fully stirring, 11ml of tri-n-propylamine was added dropwise. Then mix with the mixture of 30 grams of ZSM-5 and 45 grams of water prepared in advance, and then aging and aging for a certain period of time. The aging and aging time varies with temperature, and the time is shorter when the temperature is high;

Put the above gel into a white steel tank lined with a polytetrafluoroethylene inner membrane, heat crystallization at a constant temperature of 165°C for 72 hours, and recover the product. Exchange with 20% NH ₄ NO ₃ aqueous solution for 3 hours; after several times of filtration and washing, dry at 110°C for 2 hours, and then bake at 550°C for 6 hours to obtain the finished product. The X-ray powder diffraction data of the resulting finished product has the characteristics of Table 1.

Embodiment 9:

Weigh 1.2 grams of zirconyl nitrate and 100 grams of deionized water, stir and dissolve completely in a constant temperature water bath at 30°C, add 16 grams of pseudoboehmite with a water content of 27%, stir for a certain period of time, then add 14ml of phosphoric acid dropwise, After stirring well, 15ml of tri-n-propylamine was added dropwise. Then mix with the mixture of 40 grams of ZSM-5 and 50 grams of water prepared in advance. After a certain period of aging and aging, the aging and aging time varies with temperature, and the time is short at high temperature;

Put the above gel into a white steel tank lined with a polytetrafluoroethylene inner membrane, heat crystallization at a constant temperature of 170°C for 48 hours, and recover the product. Exchange with 8% NH ₄ NO ₃ aqueous solution for 6 hours; after several times of filtration and washing, dry at 102°C for 2 hours, and then bake at 580°C for 4 hours to obtain the finished product. The X-ray powder diffraction data of the resulting finished product has the characteristics of Table 1.

Example 10:

Weigh 0.9 gram of zirconyl chloride and 108 gram of deionized water, stir and dissolve completely in a constant temperature water bath at 55°C, add 11.5 gram of pseudo-boehmite with 27% water content and stir for a certain period of time, then add 14ml of phosphoric acid dropwise, After thorough stirring, 14 ml of triethylamine was added dropwise. After a certain period of time, it is mixed with a mixture of 25 grams of ZSM-5 and 36 grams of water prepared in advance, and then aged and aged for a certain period of time. The aging and aging time varies with temperature, and the time for high temperature is short;

Put the above gel into a white steel tank lined with a polytetrafluoroethylene inner membrane, heat crystallization at a constant temperature of 105°C for 96 hours, and recover the product. Exchange with 15% NH ₄ NO ₃ aqueous solution for 7 hours; after several times of filtration and washing, dry at 105°C for 2 hours, and then bake at 620°C for 3 hours to obtain the finished product. The X-ray powder diffraction data of the resulting finished product has the characteristics of Table 1.

Example 11:

Weigh 1.6 grams of zirconium oxychloride and 150 grams of deionized water, stir and dissolve completely in a constant temperature water bath at 85°C, then add 20 grams of pseudoboehmite with a water content of 27% and stir for a certain period of time, then add 25ml of Phosphoric acid, stir well and then add 26ml triethylamine dropwise. After stirring for a certain period of time, mix it with a mixture of 40 grams of ZSM-5 and 55 grams of water prepared in advance, and then aging and aging for a certain period of time. The aging and aging time varies with temperature, and the time for high temperature is short;

Put the above gel into a white steel tank lined with a polytetrafluoroethylene inner membrane, heat crystallization at a constant temperature of 175°C for 72 hours, and recover the product. Exchange with 6% NH ₄ NO ₃ aqueous solution for 4 hours, then filter and wash several times, dry at 105°C for 2 hours, and then bake at 650°C for 2 hours. The X-ray powder diffraction data of the finished product are listed in Table 1 Characteristics.

In addition to the raw materials used in the foregoing embodiments, the heteroatom source M can also be selected from one or more elements selected from silicon, boron, germanium, gallium, manganese, titanium, iron, cobalt and nickel; An organoaluminum source, ie aluminum isopropoxide, can be used; the template R can also be selected from one or a mixture of two or more of diethanolamine, di-n-propylamine or tetraethylamine. These raw materials can also achieve the purpose of practicing the present invention.

Attached Table 1: X-ray Powder Diffraction Data Sheet of the Finished Product

Peak No 2Theta d-value Intensity I/I₀

1 7.900 11.1820 7110 86 2 8.800 10.0403 5782 70 3 9.100 9.7099 4232 52 4 12.900 6.8569 5202 64 5 13.600 6.5055 5002 60 6 13.900 6.3658 1696 twenty two 7 14.700 6.0211 1858 twenty four 8 15.500 5.7121 1416 18 9 15.900 5.5693 1510 20 10 18.300 4.8439 5196 64 11 20.300 4.3710 1430 18 12 20.800 4.2670 6798 82 13 23.000 3.8636 8378 100 14 23.700 3.7511 3370 42 15 23.900 3.7201 4518 54 16 24.400 3.6450 2918 36 17 25.800 3.4503 1526 20 18 26.200 3.3985 3200 40 19 29.100 3.0661 6770 82 20 29.900 2.9859 1500 18 twenty one 30.400 2.9379 1582 20 twenty two 33.400 2.6805 2804 34

Conclusion: the method of the present invention has synthesized a kind of ZSM-5 (nucleus)/MAPO-5 (shell) type double structure molecular sieve, and it is that a kind of inner core has the acidity and channel characteristics of ZSM-5, and outer layer has the characteristic of MAPO-5. Molecular sieve with acidic and pore characteristics. The inner core of the dual-structure molecular sieve has silicon and aluminum molecular sieves with zeolite structure, and the outer layer is a new three-dimensional structure composed of AlO ₄ , PO ₄ and MO ₄ tetrahedrons. This double-structure molecular sieve As a catalytic material, structural molecular sieves can take advantage of the different advantages of core and shell molecular sieves, which is beneficial to the catalytic reaction. In the catalytic cracking of heavy oil, larger molecules can be cracked in the shell layer (MAPO-5) first. , and then smaller molecules enter the inner core, and further cracking nuclear isomerization is carried out on ZSM-5, which effectively optimizes the catalyst pore distribution and acidity distribution, and is used in heavy oil catalytic cracking, catalytic cracking, hydrocracking and other fine It has potential application value in chemical industry.

Claims (6)

1. a kind of synthetic method of ZSM-5 and MAPO-5 double-structure molecular sieve, it is characterized in that: this double-structure molecular sieve is used as the catalyst in heavy oil catalytic cracking, and method is to take by weighing a kind of heteroatom source M, aluminum source, Phosphorus source, template agent, ZSM-5 and deionized water are used as raw materials, and the ratio of each raw material in terms of moles is: M _x O _y : Al ₂ O ₃ : P ₂ O ₅ : R: _{H 2} O = 0.5～1.5: 5～15: 4～20: 4～20: 100～2000; where: X, Y respectively represent the number of atoms of the heteroatom source M and O atoms; R represents the template agent; ZSM-5 is the original powder of ZSM-5, ZSM-5 and the above-mentioned mixture are taken in any proportion, and the raw materials are mixed and stirred evenly at 10°C-95°C, then aged and aged, and crystallized by constant temperature water at 20°C-200°C for 5-200 hours, and The product obtained after crystallization is recovered, and the finished catalyst is obtained by filtering, washing, exchanging, drying, and roasting; the template R is selected from one or both of triethylamine and tri-n-propylamine; the The heteroatom source M is a zirconium source, and the zirconium source is selected from one of zirconium oxide, zirconyl chloride, zirconyl nitrate, zirconium sulfate, zirconium ethoxide, zirconium propoxide, zirconium formate, and zirconium acetate. 2. A method for synthesizing ZSM-5 and MAPO-5 double-structured molecular sieves according to claim 1, characterized in that: the phosphorus source is phosphoric acid. 3. A method for synthesizing ZSM-5 and MAPO-5 dual-structure molecular sieves according to claim 1, characterized in that: the aluminum source is an inorganic aluminum source or an organic aluminum source. 4. the synthetic method of a kind of ZSM-5 and MAPO-5 double structure molecular sieve according to claim 3 is characterized in that: described inorganic aluminum source is selected from sodium metaaluminate, aluminum chloride or pseudoboehmous aluminum Stone; The organoaluminum source is aluminum isopropoxide. 5. the synthetic method of a kind of ZSM-5 and MAPO-5 double structure molecular sieve according to claim 1 is characterized in that: ZSM-5 former powder and deionized water are mixed according to any proportion before synthesizing catalyst, stir evenly spare. 6. A method for synthesizing ZSM-5 and MAPO-5 dual-structure molecular sieves according to claim 1, characterized in that: the aging process is aging at a temperature of 30°C to 60°C for 30 minutes to 5 hours; The aging process is aging for 30 minutes to 60 hours at a temperature of 24 ° C to 40 ° C; the filtering and washing process is 1 to 4 times; the washing process uses deionized water to wash; the described The drying process is drying at 100°C to 110°C for 2 to 6 hours; the hydrothermal crystallization process is at 20°C to 200°C for 5 to 200 hours; the exchange process is at 20 Exchanging with NH ₄ NO ₃ aqueous solution with a concentration of 1% to 20% for 1 to 24 hours at °C to 95 °C; the roasting process is to roast at 500 °C to 650 °C for 2 to 7 hours.