CN101935047B - MAPSO (Modified Adaptive Particle Swarm Optimization) molecular sieve and synthetic method thereof - Google Patents

Abstract

The invention discloses a MAPSO (Modified Adaptive Particle Swarm Optimization) molecular sieve and a synthetic method thereof. The molecular sieve is characterized in that X-ray diffraction data obtained before roasting and removing a template at least comprises a diffraction peak in a table (1), and X-ray diffraction data obtained after roasting and removing the template at least comprises a diffraction peak in a table (2). The molecular sieve is prepared by mixing an aluminum source, a phosphorus source, a silicon source and an organic template into glue at 5-100 DEG C, aging the glue for 5-80 h at 5-90 DEG C for 5-80 h, and adding and hydrothermally crystallizing an IIA-group metal element compound and 0.1-15 percent by weight of seed crystal in dry basis, and hydrothermally crystallizing.

Description

A kind of MAPSO molecular sieve and synthetic method thereof

technical field

The invention relates to a MAPSO molecular sieve and a synthesis method thereof.

Background technique

Aluminum phosphate molecular sieve is a new generation of molecular sieve (USP4310440) invented by UCC Corporation in the United States in the early 1980s. It is electrically neutral, so it has no cation exchange performance and catalytic reaction performance. Aluminum phosphate molecular sieves are a series of molecular sieves with unique XRD characteristic spectra and data. Among them, there are molecular sieves with the same crystal structure as the existing aluminum silicate molecular sieves, and there are also new structures that are not found in the existing aluminum silicate molecular sieves. of molecular sieves.

Introducing silicon into the framework of aluminum phosphate molecular sieves will become silicoaluminophosphate molecular sieves, that is, SAPO series molecular sieves (UCC, USP4440871). Negatively charged, there are balance cations outside the framework, so it has cation exchange performance. When the cation outside the framework is H ⁺ , the molecular sieve has an acidic center, so it has acid catalytic reaction performance. As the active component of catalyst, silicoaluminophosphate molecular sieve has been widely used in the fields of oil refining and petrochemical industry, such as catalytic cracking, hydrocracking, isomerization, alkylation of aromatic hydrocarbons, conversion of oxygen-containing organic compounds, etc.

Aluminum phosphate molecular sieves and silicoaluminophosphate molecular sieves have been rapidly developed due to their wide range of uses and potential application fields, and molecular sieves with new structures and synthesis methods have been invented continuously.

Chinese patent CN 1485272A discloses a silicoaluminophosphate molecular sieve (SRM-2) with a novel structure, and its XRD data before the template agent is removed by roasting contains at least the diffraction peaks shown in Table A: X after the template agent is removed by roasting - The ray diffraction data contain at least the diffraction peaks of Table B; the molar composition of the molecular sieve before the template is removed by roasting is expressed as Al ₂ O ₃ : yP ₂ O ₅ : zSiO ₂ in the anhydrous chemical formula of the oxide form, where the value of y The value of z is 0.01～1.5, and the value of z is 0.05～50; the molar composition of the molecular sieve before the template agent is removed by roasting is expressed by the anhydrous chemical formula of oxide form as xR: Al ₂ O ₃ : yP ₂ O ₅ : zSiO ₂ ,

Table A

*W0～20%, M20～60%, S60～80%, VS80～100%.

Form B

Contents of the invention

The object of the present invention is to provide a MAPSO molecular sieve and its synthesis method. When the molecular sieve is especially applied in the catalytic conversion reaction process of oxygen-containing compounds, it has outstanding catalytic performance.

The present invention provides a MAPSO molecular sieve, which is characterized in that the X-ray diffraction data before calcination to remove the template agent at least contains the diffraction peaks shown in Table 1, and the X-ray diffraction data after calcination and removal of the template agent contains at least those in Table 2. Diffraction peak; its molar composition is represented by the anhydrous chemical formula of oxide form as xR: _{Al 2} O ₃ : yP ₂ O _{5 :} zSiO ₂ : nMO; where R is the template agent existing in the molecular sieve crystal channel, and the value of x is 0.01-8.0, preferably 0.02-7.0, more preferably 0.05-6.0; the value of y is 0.01-1.5, preferably 0.10-1.4, more preferably 0.15-1.2; the value of z is 0.01-30, preferably 0.02-20, more preferably 0.05 ~10; the value of n is 0.001~1.0, preferably 0.002~0.8, more preferably 0.003~0.6. Compared with the SRM-2 molecular sieve catalyst, the molecular sieve has a higher selectivity for light olefins when used in the reaction process of methanol to light olefins; in the reaction of ethanol dehydration to ethylene, compared with the SAPO-34 molecular sieve catalyst, it has higher selectivity. High selectivity.

Table 1

Table 2

The synthetic method for synthesizing the above-mentioned molecular sieve provided by the present invention uses one or any mixture of the following phosphorus-containing compounds such as phosphoric acid, hypophosphorous acid, phosphate and organic phosphide as the phosphorus source, preferably phosphoric acid; Use hydrated alumina (pseudo-boehmite phase), aluminum isopropoxide or aluminum phosphate or any mixture of several kinds of aluminum as the aluminum source, preferably hydrated alumina (pseudo-boehmite phase) and isopropanol Aluminum; one or any mixture of Group IIA metal oxides, Group IIA metal salts and organic compounds of Group IIA metals as Group IIA metal element compounds, among which Group IIA metal salts and metal Group IIA metal oxides are preferred, more preferably Group IIA metal oxides, Group IIA metal halide compounds, Group IIA metal nitrate compounds, and Group IIA metal sulfate compounds. One or any mixture of silica sol, active silica, tetraethyl orthosilicate or solid silica gel as silicon source, any one of diethylamine, diethylamine and triethylamine, di-n-propylamine Or a mixture of the two is a templating agent. Mix the above raw materials according to the feed ratio aR: Al ₂ O ₃ : bP ₂ O ₅ : cSiO ₂ : dMO: eH ₂ O, mix the aluminum source, phosphorus source, silicon source and organic template to form a colloid, and the colloid is aged at 5-90°C After 5-80 hours, add the group IIA metal element compound, add 0.1-15% by weight seed crystals on a dry basis, hydrothermally crystallize it and recover the product, wherein a is the number of moles of the template agent, and its value is 0.01- 10.0, preferably 0.2-8.0, more preferably 0.5-7.0, the value of b is 0.1-2.5, preferably 0.5-2.0, more preferably 0.6-1.5; the value of c is 0.01-30, preferably 0.02-20, more preferably 0.05-10 , the value of d is 0.001-1.0, preferably 0.002-0.8, more preferably 0.003-0.6; the value of e is 5-150, preferably 10-120, more preferably 15-100.

In the method provided by the present invention, although under the condition of preferred charging ratio and preferred gelling temperature and adding appropriate amount of seed crystals, the requirements for adding seed crystals and gelling sequence are not necessary, but under the general above-mentioned conditions , Selecting a certain feeding sequence has significant advantages in increasing the crystallization rate of molecular sieves, thereby shortening the crystallization time and improving the crystallinity of the product. Wherein the preferred feeding order of raw materials except metal salts can be as follows:

Mix phosphorus source, aluminum source and water in any order, add water once or several times, after stirring evenly, add template agent, silicon source and seed crystal in any order.

Mix the aluminum source and water, then add the mixed solution of phosphoric acid and water, stir evenly, then add template agent, silicon source and crystal seed in any order.

Mix the phosphorus source and the aluminum source with part of the water, stir evenly, add the template agent, the silicon source, the seed crystal and the remaining water in any order, and add the remaining water once or multiple times at any step.

Mix silicon source, aluminum source and phosphorus source, stir evenly, add templating agent, seed crystal and water in any order, water is added once or multiple times at any step.

Mix part of the water, silicon source, aluminum source, and phosphorus source, and after stirring evenly, add template agent, seed crystal and the remaining water in any order, and add water once or multiple times at any step.

In addition, the molecular sieve seed crystal of the present invention is selected from the molecular sieve (SRM-2) synthesized by Chinese patent CN 1485272A or the molecular sieve of the present invention. It is used as a crystal seed in the synthesis method of , and the added amount of the seed crystal is 0.1-15m% of the dry basis of the molecular sieve, preferably 0.5-14m%.

In the synthesis method provided by the present invention, said gelling temperature is 5-100°C, preferably 10-90°C, more preferably 15-80°C; the crystallization temperature is 100-250°C; the crystallization time is 4 to 500 hours, preferably 10 to 100 hours.

In the synthesis method provided by the present invention, the crystallization conditions may be to first raise the temperature to 100-160°C, keep the temperature constant for 0.5-20 hours, then raise the temperature to 165-250°C and continue the crystallization for 3-200 hours, preferably 6-100 hours .

For the molecular sieve provided by the present invention, the condition for said calcination to remove the template agent is to calcine at 300-800° C. for 1-30 hours.

Although the MAPSO molecular sieve with this new structure can be synthesized under both static and dynamic conditions, the preferred crystallization is carried out dynamically under autogenous pressure, such as heating and constant temperature crystallization under stirring conditions. In addition to increasing the uniformity of the system in the general sense, this stirring condition also includes increasing the efficiency of heat transfer and mass transfer, and has obvious advantages in suppressing CHA phase, AFO phase and other miscellaneous crystal phases.

The molecular sieve provided by the present invention can be used for the conversion reaction of hydrocarbons, such as the acidic component of catalysts such as catalytic cracking, hydrocracking, isomerization, catalytic dewaxing, etc., and can also be used for the conversion reaction of oxygen-containing organic compounds, such as methanol , ethanol, dimethyl ether, etc. conversion reaction.

Detailed ways

The following examples will further illustrate the present invention, but do not limit the content of the present invention thereby.

The instrument used for X-ray powder diffraction determination of molecular sieves in each embodiment and comparative example is Bruker D5005 made in Germany, using CuKα rays; the composition of molecular sieves is determined by X-ray fluorescence spectrometry.

Comparative example 1

This comparison example description carries out the synthesis of SRM-2 structure molecular sieve with the method of CN 1485272A.

Add 147.58 grams of phosphoric acid (containing 85% by weight of H ₃ PO ₄ ) and 593.43 grams of deionized water into a gelling kettle placed in a water bath at 50°C and mix them evenly. After stirring for 30 minutes, add 117.53 grams of hydrated oxygen Aluminum (namely, pseudo-boehmite, containing 69.4% by weight of Al ₂ O ₃ , a commercial product of Changling Petrochemical Co., Ltd. Catalyst Factory), was stirred and mixed for 2 hours. Then, 118.21 grams of diethylamine was added to the above-mentioned gelling kettle, and after stirring and mixing for 1 hour, 96.13 grams of silica sol (containing 30% by weight of SiO ₂ , Beijing Feilong Ma Kemao Co., Ltd.) was added, stirred evenly, and then added 11.79 grams of SRM-2 molecular sieves were stirred well for 2 hours to prepare a reaction mixture. The reaction mixture was sealed in a stainless steel crystallization kettle, and stirred and crystallized at 185° C. and autogenous pressure for 40 hours. Then filter, wash, and dry the crystallized product at 100-110°C to obtain the original molecular sieve powder product. Part of the crystallized product was taken for X-ray powder diffraction measurement (scanning range is 2θ=5°-35°, the same below), and the result shows that the synthesized molecular sieve is a molecular sieve with SRM-2 structure.

Take part of the above-mentioned raw molecular sieve powder, raise the temperature to 550° C. in a roasting furnace and keep the temperature constant for 3 hours, and then naturally cool to room temperature in the air. The molar composition of the molecular sieve framework determined by X-ray fluorescence spectrometry was: Al ₂ O ₃ : 0.78P ₂ O ₅ : 0.56SiO ₂ .

Comparative example 2

Synthesis of SAPO-34 molecular sieve was carried out by the method of patent ZL99126308.1.

249.4 grams of phosphoric acid (containing 88.5% by weight of H ₃ PO ₄ ) and 1025 grams of deionized water were mixed and stirred uniformly in a gelling kettle placed in a water bath at 25°C, and 204 grams of hydrated alumina was added thereto after stirring for 30 minutes (that is, pseudo-boehmite, containing 72% by weight of Al ₂ O ₃ , a commercial product of Changling Petrochemical Co., Ltd. Catalyst Factory) was stirred and mixed for 2 hours. Then, 105.0 grams of diethylamine (chemically pure reagent) and 57.2 grams of triethylamine were added into the above-mentioned gelling kettle, and the stirring and mixing were continued for 1 hour. Finally, 194.1 g of silica sol (containing 26% by weight of SiO ₂ , a commercial product of Qingdao Haiyang Chemical Factory) was added and stirred thoroughly for 2 hours to prepare a reaction mixture. The reaction mixture was sealed in a stainless steel crystallization kettle, and stirred and crystallized at 180° C. under autogenous pressure for 48 hours. Then filter, wash, and dry the crystallized product at 100-110°C to obtain the original molecular sieve powder product. Part of the crystallized product was taken for X-ray powder diffraction measurement, and the result showed that the synthesized molecular sieve was a molecular sieve with a CHA structure, that is, SAPO-34 molecular sieve.

Take part of the above-mentioned raw molecular sieve powder, raise the temperature to 550° C. in a roasting furnace and keep the temperature constant for 3 hours, and then naturally cool to room temperature in the air. The molar composition of the molecular sieve framework determined by X-ray fluorescence spectrometry was: Al ₂ O ₃ : 0.75P ₂ O ₅ : 0.52SiO ₂ .

Example 1

The mixed solution of 184.47 grams of phosphoric acid and 605.07 grams of deionized water was added to a gelling kettle placed in a water bath at 50° C., mixed and stirred for 30 minutes, and 117.53 grams of hydrated alumina (i.e. pseudo-boehmite, containing 69.4% by weight Al ₂ O ₃ , Changling Petrochemical Company Catalyst Factory commercial product, the same below), after continuing to stir for 2 hours, add 64.09 grams of silica sol (containing 30% by weight of SiO ₂ , Beijing Feilongma Science and Trade Co., Ltd.), fully stir After 2 hours, add 118.21 grams of diethylamine to the above-mentioned gelling kettle, stir evenly, and leave it to age at room temperature for 16 hours, then add 8.30 grams of magnesium chloride crystals (containing 98% by weight of MgCl ₂ 6H ₂ O, the same below, Tianjin City Guangfu Fine Chemical Research Institute), after stirring for 30 minutes, add 14.32 grams of SRM-2 molecular sieve powder, continue to stir for 30 minutes, seal the reaction mixture into a stainless steel crystallization kettle, raise the temperature to 150°C and stir for 16 hours , and then raised to 185°C for 84 hours of crystallization under autogenous pressure. Then filter, wash, and dry the crystallized product at 100-110°C to obtain the original molecular sieve powder product. Part of the crystallized product was taken for X-ray powder diffraction measurement, and the results are shown in Table 7, which conforms to Table 1, indicating that it is the SRM-6 referred to in the present invention.

Take part of the above-mentioned raw molecular sieve powder, raise the temperature to 550° C. in a roasting furnace and keep the temperature constant for 3 hours, and then naturally cool to room temperature in the air. Part of the crystallized product was taken for X-ray powder diffraction measurement, and the results are shown in Table 8; the molar composition of the molecular sieve skeleton determined by X-ray fluorescence spectrometry was: Al ₂ O ₃ : 0.89P ₂ O ₅ : 0.43SiO ₂ : 0.076MgO.

table 3

Table 4

Example 2

Add 1121.49 grams of silica sol, 117.53 grams of hydrated alumina and 294.24 grams of deionized water into a gelling kettle placed in a 70°C water bath, mix and stir for 30 minutes, add 221.36 grams of phosphoric acid into the gelling kettle and stir for 2 hours, 354.62 g of diethylamine was added into the above-mentioned gelling still, and stirred thoroughly for 2 hours to prepare a reaction mixture. Stir evenly and age at 35°C for 24 hours, then add 6.55 grams of magnesium oxide powder (containing 98.5% by weight of MgO, the same below, Sinopharm Chemical Reagent Co., Ltd.), stir for 30 minutes, then add 48.49 grams of SRM-2 The raw molecular sieve powder was stirred for 30 minutes, the reaction mixture was packed into a stainless steel crystallization kettle, the temperature was raised to 120°C and stirred for 4 hours, and then raised to 210°C for 20 hours under autogenous pressure for crystallization. Then filter, wash, and dry the crystallized product at 100-110°C to obtain the original molecular sieve powder product. Part of the crystallized product was taken for X-ray powder diffraction measurement, and the results are shown in Table 5, which conforms to Table 1, indicating that it is the SRM-6 referred to in the present invention.

Take part of the above-mentioned raw molecular sieve powder, raise the temperature to 550° C. in a roasting furnace and keep the temperature constant for 3 hours, and then naturally cool to room temperature in the air. Part of the crystallized product was taken for X-ray powder diffraction measurement, and the results are shown in Table 6; the molar composition of the molecular sieve skeleton determined by X-ray fluorescence spectrometry was: Al ₂ O ₃ : 0.32P ₂ O ₅ : 5.34SiO ₂ : 0.25MgO.

table 5

Table 6

Example 3

117.53 grams of hydrated alumina and 305.72 grams of deionized water were added to a gelling kettle placed in a water bath at 25°C, mixed and stirred evenly and stirred for 30 minutes, and 147.58 grams of phosphoric acid (containing 85% by weight of H ₃ PO ₄ , the same below ) was added into the gelling kettle and continued to stir for 2 hours. After adding 88.65 grams of diethylamine into the above-mentioned gelling kettle, after stirring for 1 hour, add 96.13 grams of silica sol, stir well and then stir and age at 50°C for 10 hours, add 16.37 grams of magnesium oxide powder and stir for 30 minutes, add 14.15 grams of The roasted SRM-2 molecular sieves were fully stirred for 2 hours to prepare a reaction mixture. The reaction mixture was packaged into a stainless steel crystallization kettle, stirred and crystallized at 185° C. under autogenous pressure for 48 hours. Then filter, wash, and dry the crystallized product at 100-110°C to obtain the original molecular sieve powder product. Part of the crystallized product was taken for X-ray powder diffraction measurement, and the results are shown in Table 3, which conforms to Table 1, indicating that it is the SRM-6 referred to in the present invention.

Take part of the above-mentioned raw molecular sieve powder, raise the temperature to 550° C. in a roasting furnace and keep the temperature constant for 3 hours, and then naturally cool to room temperature in the air. Part of the crystallized product was taken for X-ray powder diffraction measurement, and the results are shown in Table 4; the molar composition of the molecular sieve skeleton determined by X-ray fluorescence spectrometry was: Al ₂ O ₃ : 0.73P ₂ O ₅ : 0.54SiO ₂ : 0.39MgO.

Table 7

Table 8

Example 4

117.53 grams of hydrated alumina and 488.87 grams of deionized water were added to the gelling kettle placed in a water bath at 35°C, mixed and stirred for 30 minutes, 129.13 grams of phosphoric acid was added, and stirring was continued for 2 hours, and 118.21 grams of diethylamine was added to the In the above-mentioned gelling kettle, after stirring evenly, put it under 60 for static aging for 15 hours, add 16.60 grams of magnesium chloride crystals, stir for 30 minutes, add 14.07 grams of SRM-2 molecular sieve powder, and stir for another 30 minutes, then add 32.04 grams of silica sol , and stirred well for 2 hours to prepare a reaction mixture. Part of the reaction mixture was packaged into a stainless steel crystallization kettle, the temperature was raised to 130°C and stirred for 8 hours, and then raised to 200°C for 36 hours under autogenous pressure to crystallize with stirring. Then filter, wash, and dry the crystallized product at 100-110°C to obtain the original molecular sieve powder product. Part of the crystallized product was taken for X-ray powder diffraction measurement, and the results are shown in Table 9, which conforms to Table 1, indicating that it is the SRM-6 referred to in the present invention.

Take part of the above-mentioned raw molecular sieve powder, raise the temperature to 550° C. in a roasting furnace and keep the temperature constant for 3 hours, and then naturally cool to room temperature in the air. Part of the crystallized product was taken for X-ray powder diffraction measurement, and the results are shown in Table 10; the molar composition of the molecular sieve skeleton determined by X-ray fluorescence spectrometry was: Al ₂ O ₃ : 0.83P ₂ O ₅ : 0.35SiO ₂ : 0.15MgO.

Table 9

Table 10

Example 5

Add 117.53 grams of hydrated alumina and 376.67 grams of deionized water into the gelling kettle placed in a water bath at 60°C, mix and stir for 30 minutes, add 184.47 grams of phosphoric acid into the gelling kettle and stir for 2 hours. Add 160.21 grams of silica sol into the above-mentioned gelling kettle, continue stirring and mixing for 1 hour, add 147.76 grams of diethylamine, stir fully for 2 hours to make a reaction mixture, leave it at room temperature for static aging for 24 hours, add 30.00 grams of chlorinated Calcium hydrate (containing 98% by weight of CaCl ₂ 2H ₂ O, Tianjin Tanggu Binhai Chemical Refrigeration Appliance Factory), stirred evenly, added 33.49 grams of SRM-2 molecular sieve powder and stirred for 30 minutes, and encapsulated part of the reaction mixture into stainless steel for crystallization In the kettle, the temperature was raised to 140°C and stirred for 8 hours, then raised to 175°C and stirred for 36 hours under autogenous pressure for crystallization. Then filter, wash, and dry the crystallized product at 100-110°C to obtain the original molecular sieve powder product. Part of the crystallized product was taken for X-ray powder diffraction measurement, and the results are shown in Table 11, which conforms to the characteristics of Table 1, indicating that it is SRM-6.

Take part of the above-mentioned raw molecular sieve powder, raise the temperature to 550° C. in a roasting furnace and keep the temperature constant for 3 hours, and then naturally cool to room temperature in the air. Part of the crystallized product was taken for X-ray powder diffraction measurement, and the results are shown in Table 12; X-ray fluorescence spectrometry was used to determine the molar composition of the skeleton of the sample molecular sieve, and the molar composition of the anhydrous oxide was: Al ₂ O ₃ : 0.64P ₂ O ₅ : 0.79 SiO ₂ : 0.19 CaO.

Table 11

Table 12

Example 6

Add 117.53 grams of hydrated alumina and 351.01 grams of deionized water to a gelling kettle placed in a water bath at 50°C, mix and stir evenly, and stir for 30 minutes. Add 147.58 grams of phosphoric acid to the gelling kettle and stir for 30 minutes. After aging at 25° C. for 20 hours, 31.99 g of strontium chloride crystals (containing 100% by weight of SrCl ₂ ·6H ₂ O, Beijing Xinhua Chemical Reagent Factory) were added. After uniform stirring for 2 hours, add 7.36 grams of SRM-2 molecular sieve powder into the above-mentioned gelling kettle, continue stirring and mixing for 30 minutes, add 351.01 grams of deionized water and stir for 30 minutes, add 118.21 grams of diethylamine, and stir After 10 minutes, 163.56 g of di-n-propylamine was added, and after stirring for 1 hour, 128.17 g of silica sol was added and stirred thoroughly for 2 hours to prepare a reaction mixture. Part of the reaction mixture was packaged into a stainless steel crystallization kettle, the temperature was raised to 130°C and stirred for 15 hours, then raised to 200°C and stirred for 16 hours under autogenous pressure for crystallization. Then filter, wash, and dry the crystallized product at 100-110°C to obtain the original molecular sieve powder product.

Part of the crystallized product was taken for X-ray powder diffraction measurement, and the results are shown in Table 13, which conforms to the characteristics of Table 1, indicating that it is SRM-6. Take part of the above-mentioned molecular sieve raw powder, raise the temperature to 550 ° C in a roasting furnace and keep the temperature constant for 3 hours, then naturally cool to room temperature in the air, take part of the crystallized product for X-ray powder diffraction measurement, the results are shown in Table 14; X The molar composition of the skeleton of the sample molecular sieve was determined by ray fluorescence spectrometry. The molar composition of the anhydrous oxide was: Al ₂ O ₃ : 0.78P ₂ O ₅ : 0.63SiO ₂ : 0.081SrO.

Table 13

Table 14

Comparative example 3

Add 117.53 grams of hydrated alumina and 605 grams of deionized water into a gelling kettle placed in a water bath at 40°C, mix and stir for 30 minutes, add 147.6 grams of phosphoric acid into the gelling kettle and stir for 2 hours, then add 32.04 grams of silica sol, 103.4 grams of diethylamine was added into the above-mentioned gel forming kettle, and stirred thoroughly for 30 minutes to prepare a reaction mixture. Then add 6.55 grams of magnesium oxide powder (containing 98.5% by weight of MgO, the same below, Sinopharm Chemical Reagent Co., Ltd.), after stirring for 30 minutes, add the former powder of molecular sieve of 40 grams of SRM-2, stir for 30 minutes, and seal the reaction mixture Put it into a stainless steel crystallization kettle, raise the temperature to 185°C and stir at a constant temperature for 48 hours. Then filter, wash, and dry the crystallized product at 100-110°C to obtain the original molecular sieve powder product. Part of the crystallized product was taken for X-ray powder diffraction measurement, and the results showed that the product was a mixture of SRM-6, a large amount of MgALPO-34 and a small amount of SAPO-41.

Example 7

This example illustrates the effect of the molecular sieve provided by the present invention in the reaction of preparing olefins from methanol.

The raw molecular sieve powder synthesized in Comparative Example 1 and Examples 1-6 was calcined at 550°C for 4 hours, then cooled to room temperature, and a part of it was pressed into tablets, crushed and sieved to obtain particles with a particle size of 20-40 mesh as the catalyst DB- 1. and Catalysts A-F.

Reaction evaluations were performed on a pulsed microreactor. The test parameters are as follows: the reaction temperature is 500° C., and the pressure is normal pressure. The loading amount of the catalyst is 100 mg; the reactant is methanol, the injection volume is 0.5 μl, and the reaction product is analyzed by an online gas chromatograph. The chromatographic conditions are: the flow rates of hydrogen and nitrogen are both 30mL/min, the air flow rate is 300mL/min, the initial temperature of the chromatographic column is 40°C, after a constant temperature of 40°C for 1min, the temperature is programmed to rise to 150°C at a rate of 10°C/min, and then Keep the temperature at 150°C for 2 minutes, the temperature of the injection port is 150°C, and the temperature of the FID detector is 180°C. The reaction product is C ₂ -C ₄ olefins as target products. The evaluation results are shown in Table 15.

Table 15

It can be seen from Table 15 that compared with the SRM-2 molecular sieve catalyst, the molecular sieve provided by the present invention has higher selectivity for low-carbon olefins when used to catalyze the MTO reaction.

Example 8

This example illustrates the effect of the molecular sieve provided by the present invention in the reaction of preparing ethylene from ethanol.

Catalyst preparation is the same as in Example 7.

The catalyst prepared in Comparative Example 2 was DB-2.

Reaction evaluations were performed on a pulsed microreactor. The test parameters are: the reaction temperature is 350° C., and the pressure is normal pressure. The loading amount of the catalyst is 100 mg; the reactant is ethanol, the injection volume is 0.5 μl, and the reaction product is analyzed by an online gas chromatograph. The chromatographic conditions are: the flow rates of hydrogen and nitrogen are both 30mL/min, and the air flow rate is 300mL/min; the initial temperature of the chromatographic column is 40°C, and after a constant temperature of 40°C for 1min, the temperature is programmed to rise to 150°C at a heating rate of 10°C/min, and then Keep the temperature at 150°C for 2 minutes, the temperature of the injection port is 150°C, and the temperature of the FID detector is 180°C.

The reaction product has _C2 olefins as the target product.

The evaluation results are shown in Table 16.

Table 16

Catalyst Ethanol conversion rate (%) Ethylene selectivity (%) DB-2 100 98.54 A 100 99.84 B 100 99.70 C 100 99.68 D 100 99.91 E 100 99.45 F 100 99.51

As shown in Table 16, compared with the SAPO-34 molecular sieve catalyst, the molecular sieve of the present invention has higher selectivity in catalyzing the reaction of ethanol dehydration to ethylene.

Claims (18)

1. A MAPSO molecular sieve is characterized in that the X-ray diffraction data before roasting and removing the template agent contains at least the diffraction peak shown in Table 1, and the X-ray diffraction data after roasting and removing the template agent contains at least the diffraction of Table 2 The peak and its molar composition are represented by the anhydrous chemical formula in oxide form as Al ₂ O ₃ : yP ₂ O ₅ : zSiO ₂ : nMO, M is a group IIA metal element, wherein the value of y is 0.01-1.5, and the value of z is 0.01～30, the value of n is 0.001～1.0, W, M, S, VS in the table represent the relative intensity relative to the strongest diffraction peak, W is 0～20%, M is 20～60%, S is 60～ 80%, VS is 80~100%, Table 1

Table 2

2. The molecular sieve according to claim 1, wherein the value of y is 0.1-1.4; the value of z is 0.02-20; the value of n is 0.002-0.8. 3. According to the molecular sieve of claim 1, its molar composition before the calcination removes template agent is xR: Al ₂ O ₃ : yP ₂ O ₅ : zSiO ₂ : nMO when expressed by the anhydrous chemical formula of oxide form; Wherein R is For the template agent present in the molecular sieve crystal channel, the value of x is 0.01-8.0, and the values of y, z and n are as defined in claim 1. 4. The molecular sieve according to claim 3, wherein x has a value from 0.02 to 7.0. _5. The method for synthesizing molecular _sieves according _{to claim} 1, characterized in that the aluminum _source , _phosphorus Silicon source, silicon source, water and organic template are mixed to form a colloid, and after the colloid is aged at 5-90°C for 5-80 hours, a group IIA metal element compound is added, and then 0.1-15% by weight of seed crystals are added on a dry basis. Hydrothermal crystallization at ~250°C for 4-500 hours, filter, wash and dry the crystallized product at 100-110°C to obtain the raw molecular sieve powder product. Take part of the above-mentioned raw molecular sieve powder and heat it up to 550°C in a roasting furnace. ℃ and constant temperature for 3 hours, and then naturally cooled to room temperature in the air; where R is an organic template, the value of a is 0.1-10.0; the value of b is 0.1-2.5, the value of c is 0.01-30.0, and the value of d is 0.001-1.0, the value of e is 5-150, and the seed crystal is selected from SRM-2 silicoaluminophosphate molecular sieve. 6. according to the method for claim 5, wherein said aluminum source is selected from one or several mixtures of pseudo-boehmite phase hydrated alumina, aluminum isopropoxide and aluminum phosphate, and said silicon source is selected from From one or any mixture of silica sol, tetraethyl orthosilicate or solid silica gel, said phosphorus source is selected from one or any mixture of phosphoric acid, hypophosphorous acid, phosphate and organic phosphide, said The organic template agent is diethylamine or a mixture of diethylamine and di-n-propylamine, and the metal element compound of group IIA is a metal oxide or metal salt of group IIA element. 7. A method according to claim 6, wherein said source of aluminum is hydrated alumina or aluminum isopropoxide and said source of phosphorus is phosphoric acid. 8. The method according to claim 6, wherein the metal salt of a group IIA element is magnesium chloride, calcium chloride or strontium chloride. 9. The method according to claim 5, wherein said seed crystals are added in an amount of 0.5 to 14% by weight. 10. The method according to claim 5, wherein said gelling is performed at a temperature of 10-90°C. 11. According to the method of claim 5, the crystallization condition is to first raise the temperature to 100-160°C, keep the temperature constant for 0.5-20 hours, then raise the temperature to 165-250°C and continue the crystallization for 3-200 hours. 12. The method according to claim 5, wherein a has a value of 0.2 to 8.0. 13. The method according to claim 5, wherein b has a value of 0.5 to 2.0. 14. The method according to claim 5, wherein c has a value of 0.02 to 20.0. 15. The method according to claim 5, wherein d has a value of 0.002 to 0.8. 16. The method according to claim 5, wherein e has a value of 10-120. 17. The method according to claim 5, wherein said aging has a temperature of 10-70°C and an aging time of 10-50 hours. 18. The method according to claim 5, wherein said hydrothermal crystallization is carried out statically or dynamically under autogenous pressure.