SAPO-35 / SAPO-34 coexisting molecular sieve, its preparation method and application, and molecular sieve composition and its application

Abstract

The present invention belongs to the field of molecular sieves, and specifically discloses a SAPO-35 / SAPO-34 symbiotic molecular sieve and its preparation method and application, as well as a molecular sieve composition and its application; the preparation method of the SAPO-35 / SAPO-34 symbiotic molecular sieve includes the following steps: performing one-step heating crystallization treatment on a mixture formed by an aluminum source, a phosphorus source, a silicon source, methyltriethylammonium hydroxide, and water to obtain the SAPO-35 / SAPO-34 symbiotic molecular sieve; wherein, the aluminum source is calculated as Al2O3, the phosphorus source is calculated as P2O5, the silicon source is calculated as SiO2, methyltriethylammonium hydroxide (R), and water, and the molar ratio is Al2O3:P2O5:SiO2:R:H2O = 1:0.65-1.40:0.01-0.65:1.50-2.50:63-120, and the mixture is crystallized at 150-205 °C for 0.5-7 days. This method uses relatively inexpensive methyltriethylammonium hydroxide as a template agent, and the post-treatment after the raw material crystallization is simple. The said SAPO-35 / SAPO-34 is particularly suitable for use in the reaction of preparing olefins from oxides, especially the reaction of converting methanol to ethylene and propylene, and has the characteristics of high conversion rate and higher ethylene selectivity than propylene selectivity.

Description

Technical Field

[0001] The present invention relates to a SAPO-35 / SAPO-34 coexisting molecular sieve, a preparation method and application thereof, and a molecular sieve composition and application thereof. Background Art

[0002] The SAPO-35 molecular sieve is generally synthesized by a hydrothermal or alcoholothermal method, using water or alcohol as a solvent, and a mixture composed of an aluminum source, a silicon source, a phosphorus source, a template agent, and deionized water is synthesized under its own pressure in a reaction kettle. The selection of the template agent will have a certain impact on the microstructure, elemental composition, and morphology of the synthesized molecular sieve, thereby affecting its catalytic performance.

[0003] The topological structure of the SAPO-34 molecular sieve is of the CHA type, with orthorhombic symmetry. The one-dimensional main pore channels are composed of double eight-membered rings, with a pore diameter of 0.38×0.38 nm and a framework density of 14.5.

[0004] CN110961144A discloses a coexisting composite molecular sieve with a CHA / LEV topological structure, a preparation method thereof, and an SCR application, and a composite molecular sieve is synthesized by a dual-template agent system. The molecular sieves with the LEV topological structure (SAPO-35) and the CHA topological structure (SAPO-34) are both eight-membered ring small-pore molecular sieves, but the pore diameters are different. The cage of the SAPO-35 molecular sieve (0.63×0.73 nm) is smaller than that of the SAPO-34 molecular sieve (0.67×1.0 nm). The coexistence and combination of the two molecular sieves may affect the elemental distribution in the pore channels of the molecular sieve. Therefore, the coexisting molecular sieve with the LEV topological structure and the CHA topological structure may have a beneficial effect on the performance of the catalyst. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a SAPO-35 / SAPO-34 coexisting molecular sieve with a new adjustable composition ratio and acid amount, and a preparation method of the SAPO-35 / SAPO-34 coexisting molecular sieve that is simple and feasible to operate.

[0006] According to the first aspect of the present invention, the present invention provides a SAPO-35 / SAPO-34 coexisting molecular sieve,

[0007] The SAPO-35 / SAPO-34 coexisting molecular sieve has the following anhydrous chemical composition: (Al x P y Si z )O 2·mR, where R is the template methyltriethylammonium hydroxide, x = 0.35 - 0.60, y = 0.30 - 0.50, z = 0.005 - 0.20, x + y + z = 1, m is the molar fraction of R, and m = 0.05 - 0.12;

[0008] Preferably, the molecular sieve has an X-ray diffraction pattern including the LEV structure of SAPO-35 molecular sieve and the CHA structure of SAPO-34 molecular sieve as shown in the following table,

[0009]

[0010] a: ±0.30°, b: varies with 2θ.

[0011] According to the second aspect of the present invention, the present invention provides a method for preparing a SAPO-35 / SAPO-34 intergrown molecular sieve, which method comprises:

[0012] Performing a heat crystallization treatment on a mixture containing an aluminum source, a phosphorus source, a silicon source, methyltriethylammonium hydroxide, and water;

[0013] Wherein, the aluminum source is calculated as Al 2 O 3 , the phosphorus source is calculated as P 2 O 5 , the silicon source is calculated as SiO 2 , the methyltriethylammonium hydroxide R and water, and the molar ratio is Al 2 O 3 : P 2 O 5 : SiO 2 : R: H 2 O = 1: 0.65 - 1.40: 0.01 - 0.65: 1.50 - 2.50: 63 - 120.

[0014] According to the third aspect of the present invention, the present invention provides the SAPO-35 / SAPO-34 intergrown molecular sieve prepared by the preparation method of the present invention.

[0015] According to the fourth aspect of the present invention, the present invention provides a molecular sieve composition comprising the SAPO-35 / SAPO-34 intergrown molecular sieve of the present invention and a binder.

[0016] According to the fifth aspect of the present invention, the present invention provides the use of the SAPO-35 / SAPO-34 intergrown molecular sieve of the present invention or the molecular sieve composition of the present invention as a catalyst in the organic matter conversion reaction, preferably as a catalyst in the reaction for preparing olefins from oxides, and more preferably as a catalyst in the reaction for preparing ethylene and propylene by methanol conversion.

[0017] The SAPO-35 / SAPO-34 intergrown molecular sieve of the present invention has a unique chemical composition, with adjustable composition ratio and acid amount, and has good industrial application prospects.

[0018] The preparation method of the SAPO-35 / SAPO-34 intergrown molecular sieve of the present invention is simple and feasible. Using relatively inexpensive methyltriethylammonium hydroxide as the template agent, the crystallization solution is nearly neutral, and the post-treatment is relatively simple and environmentally friendly.

[0019] The SAPO-35 / SAPO-34 described in the present invention is particularly suitable for the reaction of preparing olefins from oxides, especially the reaction of converting methanol to ethylene and propylene, and has the characteristics of high conversion rate and higher ethylene selectivity than propylene selectivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is the X-ray diffraction pattern of the molecular sieve obtained in Example 1;

[0021] Figure 2 It is the X-ray diffraction pattern of the molecular sieve obtained in Example 2. DETAILED DESCRIPTION OF THE INVENTION

[0022] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0023] The present invention provides a SAPO-35 / SAPO-34 intergrown molecular sieve, and the SAPO-35 / SAPO-34 intergrown molecular sieve has the following anhydrous chemical composition: (Al x P y Si z )O 2 ·mR, where R is the template agent methyltriethylammonium hydroxide, x = 0.35 - 0.60, y = 0.30 - 0.50, z = 0.005 - 0.20, x + y + z = 1, m is the molar fraction of R, m = 0.05 - 0.12; the molecular sieve has an X-ray diffraction pattern attributed to the LEV structure of SAPO-35 molecular sieve and the CHA structure of SAPO-34 molecular sieve as shown in the following table,

[0024]

[0025]

[0026] a: ±0.30°, b: varies with 2θ.

[0027] In the present invention, in the X-ray diffraction pattern, vw, w, m, s, and vs represent the diffraction peak intensity, where vw is very weak, w is weak, m is medium, s is strong, and vs is very strong; generally speaking, vw is less than 5%, w is 5% - 20%, m is 20% - 40% (including 20% and 40%), s is 40% - 70%, and vs is greater than 70% (including 70%).

[0028] The data in the above table represents the SAPO-35 / SAPO-34 co-crystalline molecular sieve at 2θ (°) (a) of 8.52, d-spacing of 10.370, relative intensity (I / I 0 ×100) is w (weak), and so on. Those skilled in the art are well aware of the representation method of this table, and the present invention will not elaborate on it one by one here.

[0029] The SAPO-35 / SAPO-34 co-crystalline molecular sieve of the present invention has a unique chemical composition, adjustable composition ratio and acid amount, and has good industrial application prospects.

[0030] According to a preferred embodiment of the present invention, the peak intensity of the characteristic peak belonging to the LEV structure of the SAPO-35 molecular sieve in the SAPO-35 / SAPO-34 co-crystalline molecular sieve is higher than the peak intensity of the characteristic peak belonging to the CHA structure of the SAPO-34 molecular sieve.

[0031] According to a preferred embodiment of the present invention, preferably, the SAPO-35 molecular sieve accounts for 50 - 80% by weight in the SAPO-35 / SAPO-34 co-crystalline molecular sieve. For the SAPO-35 / SAPO-34 co-crystalline molecular sieve of the present invention, the proportion of the SAPO-35 molecular sieve in the SAPO-35 / SAPO-34 co-crystalline molecular sieve is adjustable, and it has good industrial application prospects.

[0032] According to a preferred embodiment of the present invention, after calcination at 300 - 800 °C for 1 - 10 hours, preferably after calcination at 400 - 650 °C for 3 - 6 hours: the specific surface area of the SAPO-35 / SAPO-34 co-crystalline molecular sieve is 450 - 650 m 2 / g; the SAPO-35 / SAPO-34 co-crystalline molecular sieve of the present invention has a unique chemical composition, adjustable specific surface area, and has good industrial application prospects.

[0033] According to a preferred embodiment of the present invention, after calcination at 300-800 °C for 1-10 hours and preferably after calcination at 400-650 °C for 3-6 hours: the total pore volume of the SAPO-35 / SAPO-34 intergrown molecular sieve is 0.20-0.60 cm 3 / g, preferably 0.25-0.55 cm 3 / g; the SAPO-35 / SAPO-34 intergrown molecular sieve of the present invention has an adjustable pore volume and has good industrial application prospects.

[0034] According to a preferred embodiment of the present invention, after calcination at 300-800 °C for 1-10 hours and preferably after calcination at 400-650 °C for 3-6 hours: the micropore volume of the SAPO-35 / SAPO-34 intergrown molecular sieve is 0.12-0.28 cm 3 / g, preferably 0.15-0.25 cm 3 / g; the SAPO-35 / SAPO-34 intergrown molecular sieve of the present invention has an adjustable micropore volume and has good industrial application prospects.

[0035] According to a preferred embodiment of the present invention, after calcination at 300-800 °C for 1-10 hours and preferably after calcination at 400-650 °C for 3-6 hours: the acid amount of the SAPO-35 / SAPO-34 intergrown molecular sieve is 1000-2200 μmol / g, preferably 1100-2000 μmol / g; the SAPO-35 / SAPO-34 intergrown molecular sieve of the present invention has a unique chemical composition and an adjustable acid amount and has good industrial application prospects.

[0036] According to a preferred embodiment of the present invention, x = 0.38-0.57, y = 0.32-0.48, z = 0.01-0.15, x + y + z = 1, and m = 0.06-0.11. The SAPO-35 / SAPO-34 intergrown molecular sieve of the present invention has an adjustable chemical composition and has good industrial application prospects.

[0037] The SAPO-35 / SAPO-34 intergrown molecular sieve having the foregoing structure and composition of the present invention can achieve the purpose of the present invention, and there is no special requirement for its preparation method. According to a preferred embodiment of the present invention, the present invention provides a method for preparing a SAPO-35 / SAPO-34 intergrown molecular sieve, which method includes:

[0038] Performing heat crystallization treatment and post-treatment on a mixture containing an aluminum source, a phosphorus source, a silicon source, methyltriethylammonium hydroxide, and water;

[0039] Wherein, the aluminum source is in the form of Al 2 O 3Calculated as P for the phosphorus source 2 O 5 Calculated as SiO for the silicon source 2 Calculated as aluminum source, phosphorus source as P 2 O 3 : P 2 O 5 : SiO 2 : R: H 2 O = 1: 0.65 - 1.40: 0.01 - 0.65: 1.50 - 2.50: 63 - 120.

[0040] The preparation method of the SAPO-35 / SAPO-34 symbiotic molecular sieve of the present invention is simple and feasible to operate. Using relatively inexpensive methyltriethylammonium hydroxide as the template agent, the crystallization solution is nearly neutral, and the post-treatment is relatively simple and environmentally friendly. It can prepare SAPO-35 / SAPO-34 symbiotic molecular sieves with small particle size, adjustable specific surface area and acid amount, and has good industrial application prospects.

[0041] In the present invention, the dosage range of each substance is relatively wide and can be adjusted according to needs. According to the preferred embodiment of the present invention, the aluminum source is calculated as Al 2 O 3 Calculated as P for the phosphorus source 2 O 5 Calculated as SiO for the silicon source 2 Calculated as aluminum source, phosphorus source as P 2 O 3 : P 2 O 5 : SiO 2 : R: H 2 O = 1: 0.70 - 1.35: 0.02 - 0.60: 1.55 - 2.45: 65 - 110.

[0042] According to a preferred embodiment of the present invention, the aluminum source is at least one selected from pseudoboehmite, alkoxyaluminum, aluminum salt, alumina and aluminum hydroxide, and preferably pseudoboehmite.

[0043] According to a preferred embodiment of the present invention, the phosphorus source is at least one selected from phosphoric acid, ammonium hydrogen phosphate, ammonium dihydrogen phosphate and organic phosphides, and preferably phosphoric acid.

[0044] According to a preferred embodiment of the present invention, the silicon source is at least one selected from silica sol, silica gel and tetraethyl orthosilicate, and preferably silica sol.

[0045] The present invention can carry out crystallization under nearly neutral conditions. For the present invention, it is preferred that the pH value of the mixture is 6.5 - 9.0.

[0046] The method of the present invention can be carried out under seedless conditions. For the present invention, it is preferred that the mixture does not contain seeds.

[0047] In the present invention, there are no special requirements for the conditions of mixture crystallization, and conventional crystallization conditions can all be used in the present invention.

[0048] According to a preferred embodiment of the present invention, the crystallization conditions of the mixture include: crystallization at 150 - 205 °C for 0.5 - 7 days, preferably crystallization at 155 - 200 °C for 0.75 - 6 days, and more preferably crystallization at 160 - 195 °C for 0.75 - 5 days.

[0049] In the present invention, the post-treatment steps include, for example: separation, washing, drying, and optionally calcination.

[0050] According to the requirements of the present invention, after the crystallization step of the preparation method, the SAPO-35 / SAPO-34 co-crystalline molecular sieve can be separated from the obtained mixture by any conventionally known separation method. As the separation method, for example, a method of filtering, washing, and drying the mixture obtained after the crystallization step can be cited. Here, the filtration, washing, and drying can be carried out in any manner conventionally known in the art. Specifically, for example, as the filtration, the obtained product mixture can be simply suction-filtered. As the washing, for example, washing with deionized water and / or ethanol 2 - 3 times can be cited. As the drying temperature, for example, 40 - 110 °C can be cited, and as the drying time, for example, 4 - 24 h can be cited. This drying can be carried out under normal pressure or under reduced pressure.

[0051] According to the requirements of the present invention, the molecular sieve prepared by the foregoing method can also be calcined to remove the template agent and possible moisture, etc. The calcination can be carried out in any manner conventionally known in the art. For example, the calcination temperature is generally 300 - 800 °C, preferably 400 - 650 °C, and the calcination time is generally 1 - 10 hours, preferably 3 - 6 hours. In addition, the calcination is generally carried out in an oxygen-containing atmosphere, such as in an air or oxygen atmosphere.

[0052] The present invention provides the SAPO-35 / SAPO-34 co-crystalline molecular sieve prepared by the preparation method of the present invention.

[0053] As before, the SAPO-35 / SAPO-34 co-crystalline molecular sieve has the following anhydrous chemical composition: (Al x P y Si z )O 2·mR, where R is the template methyltriethylammonium hydroxide, x = 0.35 - 0.60, y = 0.30 - 0.50, z = 0.005 - 0.20, x + y + z = 1, m is the molar fraction of R, and m = 0.05 - 0.12.

[0054] According to a preferred embodiment of the present invention, the molecular sieve has an X-ray diffraction pattern attributed to the LEV structure of SAPO-35 molecular sieve and the CHA structure of SAPO-34 molecular sieve as shown in the following table;

[0055]

[0056]

[0057] a: ±0.30°, b: varies with 2θ.

[0058] According to a preferred embodiment of the present invention, the peak intensity of the characteristic peaks belonging to the LEV structure of SAPO-35 molecular sieve in the SAPO-35 / SAPO-34 intergrown molecular sieve is higher than the peak intensity of the characteristic peaks belonging to the CHA structure of SAPO-34 molecular sieve.

[0059] According to a preferred embodiment of the present invention, SAPO-35 molecular sieve accounts for 50 - 80% by weight in the SAPO-35 / SAPO-34 intergrown molecular sieve.

[0060] According to a preferred embodiment of the present invention, after calcination at 300 - 800 °C for 1 - 10 hours, preferably after calcination at 400 - 650 °C for 3 - 6 hours: the specific surface area of the SAPO-35 / SAPO-34 intergrown molecular sieve is 450 - 650 m 2 / g,

[0061] According to a preferred embodiment of the present invention, after calcination at 300 - 800 °C for 1 - 10 hours, preferably after calcination at 400 - 650 °C for 3 - 6 hours: the total pore volume of the SAPO-35 / SAPO-34 intergrown molecular sieve is 0.20 - 0.60 cm 3 / g, preferably 0.25 - 0.55 cm 3 / g.

[0062] According to a preferred embodiment of the present invention, after calcination at 300 - 800 °C for 1 - 10 hours, preferably after calcination at 400 - 650 °C for 3 - 6 hours: the micropore volume of the SAPO-35 / SAPO-34 intergrown molecular sieve is 0.12 - 0.28 cm 3 / g, preferably 0.15 - 0.25 cm 3 / g.

[0063] According to a preferred embodiment of the present invention, after calcination at 300-800 °C for 1-10 hours, preferably after calcination at 400-650 °C for 3-6 hours: the acid amount of the SAPO-35 / SAPO-34 intergrown molecular sieve is 1000-2200 μmol / g, preferably 1100-2000 μmol / g.

[0064] According to a preferred embodiment of the present invention, x = 0.38-0.57, y = 0.32-0.48, z = 0.01-0.15, x + y + z = 1, m = 0.06-0.11.

[0065] The present invention provides a molecular sieve composition comprising the SAPO-35 / SAPO-34 intergrown molecular sieve described in the present invention and a binder.

[0066] The present invention provides the use of the SAPO-35 / SAPO-34 intergrown molecular sieve described in the present invention or the molecular sieve composition as a catalyst in the organic matter conversion reaction.

[0067] According to a preferred embodiment of the present invention, the present invention provides a SAPO-35 / SAPO-34 intergrown molecular sieve, and the SAPO-35 / SAPO-34 (LEV / CHA) intergrown molecular sieve has the following anhydrous chemical composition: (Al x P y Si z )O 2 ·mR, where R is the template methyltriethylammonium hydroxide, x = 0.35-0.60, y = 0.30-0.50, z = 0.005-0.20, x + y + z = 1, m is the molar fraction of R, and m = 0.05-0.12.

[0068] According to a preferred embodiment of the present invention, in the chemical composition, x = 0.38-0.57, y = 0.32-0.48, z = 0.01-0.15, x + y + z = 1, m = 0.06-0.11.

[0069] According to a preferred embodiment of the present invention, the molecular sieve has an X-ray diffraction pattern attributed to the SAPO-35 molecular sieve (LEV) structure as shown in the following table,

[0070]

[0071] a: ±0.30°, b: varies with 2θ.

[0072] According to a preferred embodiment of the present invention, the molecular sieve has an X-ray diffraction pattern attributed to the SAPO-34 molecular sieve (CHA) structure as shown in the following table,

[0073]

[0074]

[0075] a: ±0.30°, b: varies with 2θ.

[0076] According to a preferred embodiment of the present invention, the peak intensity of the characteristic peaks belonging to the SAPO-35 (LEV) structure in the SAPO-35 / SAPO-34 intergrown molecular sieve is slightly higher than the peak intensity of the characteristic peaks belonging to the SAPO-34 (CHA) structure, and the SAPO-35 molecular sieve accounts for 50-80% in the SAPO-35 / SAPO-34 intergrown molecular sieve.

[0077] According to a preferred embodiment of the present invention, after calcination at 300-800 °C for 1-10 hours, preferably after calcination at 400-650 °C for 3-6 hours: the specific surface area of the SAPO-35 / SAPO-34 intergrown molecular sieve is 450-650 m 2 / g, the total pore volume is 0.20-0.60 cm 3 / g, preferably 0.25-0.55 cm 3 / g, the micropore volume is 0.12-0.28 cm 3 / g, preferably 0.15-0.25 cm 3 / g.

[0078] According to a preferred embodiment of the present invention, after calcination at 300-800 °C for 1-10 hours, preferably after calcination at 400-650 °C for 3-6 hours: the acid amount of the SAPO-35 / SAPO-34 intergrown molecular sieve is 1000-2200 μmol / g, preferably 1100-2000 μmol / g.

[0079] According to a preferred embodiment of the present invention, the preparation method of the SAPO-35 / SAPO-34 intergrown molecular sieve of the present invention comprises the following steps:

[0080] Performing one-step heating crystallization treatment on a mixture formed by an aluminum source, a phosphorus source, a silicon source, methyltriethylammonium hydroxide and water to obtain the SAPO-35 / SAPO-34 intergrown molecular sieve;

[0081] According to a preferred embodiment of the present invention, the aluminum source is based on Al 2 O 3 calculated, the phosphorus source is based on P 2 O 5 calculated, the silicon source is based on SiO 2 calculated, methyltriethylammonium hydroxide (R) and water, and the molar ratio is Al 2 O3 : P 2 O 5 : SiO 2 : R: H 2 O = 1: 0.65 to 1.40: 0.01 to 0.65: 1.50 to 2.50: 63 to 120.

[0082] According to a preferred embodiment of the present invention, the aluminum source is based on Al 2 O 3 calculated, the phosphorus source is based on P 2 O 5 calculated, the silicon source is based on SiO 2 calculated, methyltriethylammonium hydroxide (R) and water, with a molar ratio of Al 2 O 3 : P 2 O 5 : SiO 2 : R: H 2 O = 1: 0.70 to 1.35: 0.02 to 0.60: 1.55 to 2.45: 65 to 110.

[0083] According to a preferred embodiment of the present invention, the aluminum source is at least one selected from pseudoboehmite, alkoxyaluminum, aluminum salts, alumina, and aluminum hydroxide, the phosphorus source is at least one selected from phosphoric acid, ammonium hydrogen phosphate, ammonium dihydrogen phosphate, and organic phosphorus compounds, and the silicon source is at least one selected from silica sol, silica gel, and tetraethyl orthosilicate.

[0084] According to a preferred embodiment of the present invention, the aluminum source is pseudoboehmite, the phosphorus source is phosphoric acid, and the silicon source is silica sol.

[0085] According to a preferred embodiment of the present invention, the pH value of the mixture is 6.5 to 9.0.

[0086] According to a preferred embodiment of the present invention, the crystallization conditions of the mixture are crystallization at 150 to 205 °C for 0.5 to 7 days, preferably crystallization at 155 to 200 °C for 0.75 to 6 days, and more preferably crystallization at 160 to 195 °C for 0.75 to 5 days.

[0087] According to a preferred embodiment of the present invention, the mixture does not contain seed crystals.

[0088] The present invention provides a SAPO-35 / SAPO-34 co-crystalline molecular sieve obtained by the above preparation method, and the SAPO-35 / SAPO-34 co-crystalline molecular sieve has the following anhydrous chemical composition: (Al x P y Si z )O 2·mR, where R is the template methyltriethylammonium hydroxide, x = 0.35 - 0.60, y = 0.30 - 0.50, z = 0.005 - 0.20, x + y + z = 1, m is the molar fraction of R, and m = 0.05 - 0.12.

[0089] According to a preferred embodiment of the present invention, in the chemical composition, x = 0.38 - 0.57, y = 0.32 - 0.48, z = 0.01 - 0.15, x + y + z = 1, and m = 0.06 - 0.11.

[0090] According to a preferred embodiment of the present invention, in the SAPO-35 / SAPO-34 co-crystalline molecular sieve, the peak intensity of the characteristic peak belonging to the SAPO-35 (LEV) structure is slightly higher than the peak intensity of the characteristic peak belonging to the SAPO-34 (CHA) structure, and the SAPO-35 molecular sieve accounts for 50 - 80% in the SAPO-35 / SAPO-34 co-crystalline molecular sieve.

[0091] According to a preferred embodiment of the present invention, after calcination at 300 - 800 °C for 1 - 10 hours, preferably after calcination at 400 - 650 °C for 3 - 6 hours: the specific surface area of the SAPO-35 / SAPO-34 co-crystalline molecular sieve is 450 - 650 m 2 / g, the total pore volume is 0.20 - 0.60 cm 3 / g, preferably 0.25 - 0.55 cm 3 / g, the micropore volume is 0.12 - 0.28 cm 3 / g, preferably 0.15 - 0.25 cm 3 / g.

[0092] According to a preferred embodiment of the present invention, after calcination at 300 - 800 °C for 1 - 10 hours, preferably after calcination at 400 - 650 °C for 3 - 6 hours: the acid amount of the SAPO-35 / SAPO-34 co-crystalline molecular sieve is 1000 - 2200 μmol / g, preferably 1100 - 2000 μmol / g.

[0093] The SAPO-35 / SAPO-34 co-crystalline molecular sieve of the present invention has a unique chemical composition, adjustable composition ratio and acid amount, and has good industrial application prospects.

[0094] The preparation method of the SAPO-35 / SAPO-34 co-crystalline molecular sieve of the present invention is simple and feasible, uses relatively inexpensive methyltriethylammonium hydroxide as the template, the crystallization solution is nearly neutral, and the post-treatment is relatively simple and environmentally friendly.

[0095] The SAPO-35 / SAPO-34 described in the present invention is particularly suitable for the reaction of preparing olefins from oxides, especially the reaction of converting methanol to ethylene and propylene, and has the characteristics of high conversion rate and higher ethylene selectivity than propylene selectivity.

[0096] The following is a detailed description of the specific embodiments of the present invention. However, it should be noted that the protection scope of the present invention is not limited by these specific embodiments, but is determined by the appended claims.

[0097] All publications, patent applications, patents and other references mentioned in this specification are hereby incorporated by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings commonly understood by those skilled in the art. In case of conflict, the definitions in this specification shall prevail.

[0098] When this specification uses prefixes such as "well-known to those skilled in the art", "prior art" or similar terms to derive materials, substances, methods, steps, devices or components, etc., the objects derived by such prefixes cover those commonly used in the art at the time when this application is filed, but also include those that are not commonly used at present but will become commonly recognized in the art as suitable for similar purposes.

[0099] In the context of this specification, any matters or things not mentioned, except for the clearly stated content, directly apply those known in the art without any change. Moreover, any embodiment described herein can be freely combined with one or more other embodiments described herein, and the technical solutions or technical ideas thus formed shall be regarded as part of the original disclosure or original record of the present invention, and shall not be regarded as new content not disclosed or anticipated herein, unless those skilled in the art consider such combination to be obviously unreasonable.

[0100] In the context of this specification, for a molecular sieve, before other substances (such as template agent molecules, etc.) filled in the pores during the synthesis of the molecular sieve, except for water and metal ions, in the pores are removed, it is called a "precursor".

[0101] In the context of this specification, the structure of a molecular sieve is determined by an X-ray diffraction pattern (XRD), and the X-ray diffraction pattern (XRD) is measured by an X-ray powder diffractometer, using a Cu-Kα ray source and a nickel filter. Before the sample is tested, a scanning electron microscope (SEM) is used to observe the crystallization of the molecular sieve sample to confirm that the sample contains only one kind of crystal, that is, the molecular sieve sample is a pure phase. On this basis, XRD testing is carried out to ensure that there are no interference peaks of other crystals in the diffraction peaks of the XRD pattern.

[0102] In the context of this specification, in the XRD data of the molecular sieve, w, m, s, and vs represent the diffraction peak intensities. w is weak, m is medium, s is strong, and vs is very strong, which is well-known to those skilled in the art. Generally, w is less than 20; m is 20 - 40; s is 40 - 70; vs is greater than 70.

[0103] In the context of this specification, including in the following examples and comparative examples, the model of the X-ray powder diffractometer for the molecular sieve is the Panalytical X PERPRO type X-ray powder diffractometer, which analyzes the phase of the sample, with a CuKα ray source. Nickel filter, 2θ scanning range 2 - 50°, operating voltage 40 KV, current 40 mA, scanning rate 10° / min.

[0104] In the context of this specification, including in the following examples and comparative examples, the model of the inductively coupled plasma atomic emission spectrometer (ICP) for the molecular sieve is Varian 725-ES. The analysis sample is dissolved with hydrofluoric acid to detect the elemental content in moles.

[0105] In the context of this specification, including in the following examples and comparative examples, the micropore volume and specific surface area of the molecular sieve are measured by the nitrogen physical adsorption and desorption method (BET method): The nitrogen physical adsorption and desorption isotherm of the molecular sieve is measured using a physical adsorption instrument (such as the Micromeretic ASAP2020M physical adsorption instrument), and then calculated by the BET equation and the t-plot equation. The experimental conditions for the SAPO-35 / SAPO-34 symbiotic molecular sieve are: measurement temperature -169 °C. First, the molecular sieve is heat-treated in an air atmosphere at 550 °C for 6 hours, and then pre-treated in a vacuum at 350 °C for 4 hours before measurement.

[0106] In the context of this specification, including in the following examples and comparative examples, the acid amount of the molecular sieve is measured by NH 3 -TPD chemical adsorption - desorption curve is measured using an Altamira AMI-3300 type instrument. Before the test, the sample is activated at 550 °C for 1 h, ammonia is adsorbed at 100 °C for 20 min, and then desorbed and detected at 100 - 600 °C.

[0107] In the context of this specification, including in the following examples and comparative examples, when the catalyst undergoes the methanol catalytic conversion reaction:

[0108] The conversion rate of methanol % = (the molar amount of feed methanol - the molar amount of methanol in the product - 2 × the molar amount of dimethyl ether in the outlet mixture) / (the molar amount of feed methanol) × 100%.

[0109] When the conversion rate of methanol > 99%, it is considered that methanol is completely converted and the catalyst is not deactivated; when the conversion rate of methanol < 80%, it is considered that the catalyst is completely deactivated.

[0110] Selectivity of ethylene % = (2 × molar amount of C2 olefins in the product) / (molar amount of feed methanol - molar amount of methanol in the product - 2 × molar amount of dimethyl ether in the outlet mixture) × 100%.

[0111] Selectivity of propylene % = (3 × molar amount of C3 olefins in the product) / (molar amount of feed methanol - molar amount of methanol in the product - 2 × molar amount of dimethyl ether in the outlet mixture) × 100%.

[0112] Selectivity of other products % = (m × molar amount of C m in the product) / (molar amount of feed methanol - molar amount of methanol in the product - 2 × molar amount of dimethyl ether in the outlet mixture) × 100%.

[0113] where m is the carbon molar number of C m substance.

[0114] The present invention will be further described in detail by the following examples, but the present invention is not limited to these examples.

[0115] Example 1

[0116] Mix 27.84 g of deionized water, 22.32 g of methyltriethylammonium hydroxide solution (containing 40 wt% of methyltriethylammonium hydroxide), 5.100 g of pseudo-boehmite (containing Al 2 O 3 67.0 wt%), 7.73 g of phosphoric acid (containing H 3 PO 4 85 wt%) and 2.01 g of silica sol (containing SiO 2 40 wt%) evenly, stir at room temperature for 3 hours to obtain a mixture. The pH value of the mixture is 7.5, and the final material ratio (molar ratio) is:

[0117] P 2 O 5 / Al 2 O 3 = 1.00

[0118] SiO 2 / Al 2 O 3 = 0.40

[0119] R / Al 2 O 3 = 2.00

[0120] H 2 O / Al2 O 3 = 75

[0121] The mixture was charged into a stainless - steel reactor and crystallized by rotation at 180 °C for 3 days. After the crystallization was completed, it was centrifuged and washed three times, and then dried in an oven at 110 °C to obtain the XRD spectrum data of the sample. As shown in Table 1 and Figure 1 It is a symbiotic zeolite of SAPO - 35 / SAPO - 34 with LEV and CHA structures. Among them, the SAPO - 35 zeolite accounts for 55 wt% in the SAPO - 35 / SAPO - 34 symbiotic zeolite. The phosphorus - to - aluminum molar ratio (P 2 O 5 / Al 2 O 3 ) of the sample was measured to be 0.94 by inductively coupled plasma atomic emission spectrometry (ICP), the silicon - to - aluminum molar ratio (SiO 2 / Al 2 O 3 ) was 0.36, and the chemical composition of the zeolite was (Al 0.47 P 0.45 Si 0.08 )O 2 ·0.11R.

[0122] Table 1

[0123]

[0124]

[0125] After calcination at 550 °C for 6 hours, the specific surface area of the sample was 523 m 2 / g, the micropore volume was 0.22 cm 3 / g, and the total pore volume was 0.32 cm 3 / g. The total acid amount of the sample by NH 3 -TPD test was 1837 μmol / g.

[0126] Example 2

[0127] 27.06 g of deionized water, 22.19 g of methyltriethylammonium hydroxide solution (containing 40 wt% of methyltriethylammonium hydroxide), 5.068 g of pseudoboehmite (containing 67.0 wt% of Al 2 O 3 ), 7.68 g of phosphoric acid (containing 85 wt% of H 3 PO 4 ) and 3.00 g of silica sol (containing 40 wt% of SiO 2 ) were mixed evenly and stirred at room temperature for 3 hours to obtain a mixture. The pH value of the mixture was 7.4, and the final material ratio (molar ratio) was:

[0128] P 2 O 5 / Al 2 O 3 = 1.00

[0129] SiO 2 / Al 2 O 3 = 0.60

[0130] R / Al 2 O 3 = 2.00

[0131] H 2 O / Al 2 O 3 = 75

[0132] The mixture was charged into a stainless-steel autoclave and crystallized by rotation at 180 °C for 3 days. After crystallization, it was centrifuged and washed three times, and then dried in an oven at 110 °C to obtain the XRD spectrum data of the sample. As shown in Table 2 and Figure 2 shown, it is a co-crystalline molecular sieve of LEV and CHA-type SAPO-35 / SAPO-34. Among them, the SAPO-35 molecular sieve accounts for 75 wt% in the co-crystalline molecular sieve of SAPO-35 / SAPO-34. The phosphorus-aluminum molar ratio (P 2 O 5 / Al 2 O 3 ) of the sample was measured by inductively coupled plasma atomic emission spectrometry (ICP) to be 0.96, the silicon-aluminum molar ratio (SiO 2 / Al 2 O 3 ) was 0.45, and the chemical composition of the molecular sieve was (Al 0.46 P 0.44 Si 0.10 )O 2 ·0.11R.

[0133] Table 2

[0134]

[0135]

[0136] After calcination at 550 °C for 6 hours, the specific surface area of the sample was 505 m 2 / g, the micropore pore volume was 0.22 cm 3 / g, and the total pore volume was 0.34 cm 3 / g. The total acid amount of the sample measured by NH 3 -TPD was 2076 μmol / g.

[0137] Example 3

[0138] Mix 26.90 g of deionized water, 24.37 g of methyltriethylammonium hydroxide solution (containing 40 wt% of methyltriethylammonium hydroxide), 5.062 g of pseudoboehmite (containing 67.0 wt% of Al 2 O 3 ), 7.67 g of phosphoric acid (containing 85 wt% of H 3 PO 4 ), and 1.00 g of silica sol (containing 40 wt% of SiO 2 ) uniformly. After stirring at room temperature for 3 hours, a mixture is obtained. The pH value of the mixture is 7.7, and the final material ratio (molar ratio) is as follows:

[0139] P 2 O 5 / Al 2 O 3 = 1.00

[0140] SiO 2 / Al 2 O 3 = 0.20

[0141] R / Al 2 O 3 = 2.20

[0142] H 2 O / Al 2 O 3 = 75

[0143] Load the mixture into a stainless-steel autoclave and carry out rotational crystallization at 180 °C for 3 days. After the crystallization is completed, centrifuge and wash three times, and dry in an oven at 110 °C. The XRD spectrum data of the obtained sample are shown in Table 3, which is a symbiotic zeolite of LEV and CHA type SAPO-35 / SAPO-34. Among them, the SAPO-35 zeolite accounts for 65 wt% in the symbiotic zeolite of SAPO-35 / SAPO-34. The phosphorus-aluminum molar ratio (P 2 O 5 / Al 2 O 3 ) of the sample measured by inductively coupled plasma atomic emission spectrometry (ICP) is 0.92, the silicon-aluminum molar ratio (SiO 2 / Al 2 O 3 ) is 0.18, and the chemical composition of the zeolite is (Al 0.50 P 0.46 Si 0.04 )O 2 ·0.11R.

[0144] Table 3

[0145]

[0146]

[0147] The specific surface area of the sample obtained after calcination at 550 °C for 6 hours is 511 m 2 / g, the micropore volume is 0.21 cm 3 / g, and the total pore volume is 0.33 cm 3 / g. The total acid amount of the sample measured by NH 3 -TPD test is 1544 μmol / g.

[0148] Example 4

[0149] 26.93 g of deionized water, 18.13 g of methyltriethylammonium hydroxide solution (containing 40 wt% of methyltriethylammonium hydroxide), 5.176 g of pseudoboehmite (containing Al 2 O 3 67.0 wt%), 8.24 g of phosphoric acid (containing H 3 PO 4 85 wt%) and 1.53 g of silica sol (containing SiO 2 40 wt%) were mixed evenly and stirred at room temperature for 3 hours to obtain a mixture. The pH value of the mixture was 7.2, and the final material ratio (molar ratio) was:

[0150] P 2 O 5 / Al 2 O 3 = 1.05

[0151] SiO 2 / Al 2 O 3 = 0.30

[0152] R / Al 2 O 3 = 1.60

[0153] H 2 O / Al 2 O 3 = 68

[0154] The mixture was loaded into a stainless-steel autoclave and crystallized by rotation at 185 °C for 1.5 days. After the crystallization was completed, it was centrifuged and washed three times, and then dried in an oven at 110 °C. The XRD spectral data of the sample are shown in Table 4, which is a symbiotic zeolite of LEV and CHA type SAPO-35 / SAPO-34. Among them, the SAPO-35 zeolite accounts for 80 wt% in the symbiotic zeolite of SAPO-35 / SAPO-34. The phosphorus-aluminum molar ratio (P 2O 5 / Al 2 O 3 ) is 1.03, and the silicon-aluminum molar ratio (SiO 2 / Al 2 O 3 ) is 0.25. The chemical composition of the molecular sieve is (Al 0.46 P 0.48 Si 0.06 )O 2 ·0.11R.

[0155] Table 4

[0156]

[0157] After calcination at 550 °C for 6 hours, the specific surface area of the obtained sample is 498 m 2 / g, the micropore volume is 0.21 cm 3 / g, and the total pore volume is 0.31 cm 3 / g. The total acid amount of the sample tested by NH 3 -TPD is 1786 μmol / g.

[0158] Example 5

[0159] 25.66 g of deionized water, 19.30 g of methyltriethylammonium hydroxide solution (containing 40 wt% of methyltriethylammonium hydroxide), 4.899 g of pseudoboehmite (containing Al 2 O 3 67.0 wt%), 9.65 g of phosphoric acid (containing H 3 PO 4 85 wt%) and 0.48 g of silica sol (containing SiO 2 40 wt%) were mixed evenly. After stirring at room temperature for 3 hours, a mixture was prepared. The pH value of the mixture was 6.8, and the final material ratio (molar ratio) was:

[0160] P 2 O 5 / Al 2 O 3 = 1.30

[0161] SiO 2 / Al 2 O 3 = 0.10

[0162] R / Al 2 O 3 = 1.80

[0163] H 2 O / Al 2 O 3 = 70

[0164] The mixture was charged into a stainless-steel reactor and crystallized by rotation at 185 °C for 2 days. After crystallization, it was centrifuged and washed three times, and then dried in an oven at 110 °C. The XRD spectral data of the sample are shown in Table 5, which is a symbiotic zeolite of SAPO-35 / SAPO-34 with LEV and CHA structures. Among them, the SAPO-35 zeolite accounts for 80 wt% in the SAPO-35 / SAPO-34 symbiotic zeolite. The phosphorus-aluminum molar ratio (P 2 O 5 / Al 2 O 3 ) of the sample was measured to be 1.22 by inductively coupled plasma atomic emission spectrometry (ICP), and the silicon-aluminum molar ratio (SiO 2 / Al 2 O 3 ) was 0.08. The chemical composition of the zeolite was (Al 0.44 P 0.54 Si 0.02 )O 2 ·0.11R.

[0165] Table 5

[0166]

[0167] After calcination at 550 °C for 6 hours, the specific surface area of the sample was 514 m 2 / g, the micropore volume was 0.20 cm 3 / g, and the total pore volume was 0.34 cm 3 / g. The total acid amount of the sample measured by NH 3 -TPD was 1481 μmol / g.

[0168] Example 6

[0169] 26.29 g of deionized water, 23.76 g of methyltriethylammonium hydroxide solution (containing 40 wt% of methyltriethylammonium hydroxide), 5.170 g of pseudoboehmite (containing 67.0 wt% of Al 2 O 3 ), 9.01 g of phosphoric acid (containing 85 wt% of H 3 PO 4 ) and 0.77 g of silica sol (containing 40 wt% of SiO 2 ) were mixed evenly and stirred at room temperature for 3 hours to obtain a mixture. The pH value of the mixture was 7.0, and the final material ratio (molar ratio) was:

[0170] P 2 O 5 / Al 2 O 3 = 1.15

[0171] SiO 2 / Al 2 O 3 = 0.15

[0172] R / Al 2 O 3 = 2.10

[0173] H 2 O / Al 2 O 3 = 72

[0174] The mixture was charged into a stainless-steel autoclave and crystallized with rotation at 160 °C for 5 days. After crystallization, it was centrifuged and washed three times, and then dried in an oven at 110 °C. The XRD spectrum data of the obtained sample are shown in Table 6, which is a symbiotic zeolite of LEV and CHA-type SAPO-35 / SAPO-34. Among them, the SAPO-35 zeolite accounts for 70 wt% in the symbiotic zeolite of SAPO-35 / SAPO-34. The phosphorus-aluminum molar ratio (P 2 O 5 / Al 2 O 3 ) of the sample was measured to be 1.08 by inductively coupled plasma atomic emission spectrometry (ICP), the silicon-aluminum molar ratio (SiO 2 / Al 2 O 3 ) was 0.12, and the chemical composition of the zeolite was (Al 0.47 P 0.50 Si 0.03 )O 2 ·0.11R.

[0175] Table 6

[0176]

[0177] After calcination at 550 °C for 6 hours, the specific surface area of the obtained sample was 512 m 2 / g, the micropore volume was 0.21 cm 3 / g, and the total pore volume was 0.29 cm 3 / g. The total acid amount of the sample measured by NH 3 -TPD was 1655 μmol / g.

[0178] Example 7

[0179] 29.23 g of deionized water, 27.24 g of methyltriethylammonium hydroxide solution (containing 40 wt% of methyltriethylammonium hydroxide), 5.185 g of pseudoboehmite (containing Al 2 O 3 67.0 wt%), 7.07 g of phosphoric acid (containing H 3PO 4 85 wt%) and 1.28 g of silica sol (containing SiO 2 40 wt%) were mixed evenly and stirred at room temperature for 3 hours to obtain a mixture. The pH value of the mixture was 7.9, and the final material ratio (molar ratio) was:

[0180] P 2 O 5 / Al 2 O 3 = 0.90

[0181] SiO 2 / Al 2 O 3 = 0.25

[0182] R / Al 2 O 3 = 2.40

[0183] H 2 O / Al 2 O 3 = 80

[0184] The mixture was loaded into a stainless-steel autoclave and crystallized by rotation at 165 °C for 5 days. After crystallization, it was centrifuged and washed three times, and then dried in an oven at 110 °C. The XRD spectrum data of the obtained sample are shown in Table 7, which is a symbiotic zeolite of LEV and CHA type SAPO-35 / SAPO-34. Among them, the SAPO-35 zeolite accounts for 65 wt% in the symbiotic zeolite of SAPO-35 / SAPO-34. The phosphorus-aluminum molar ratio (P 2 O 5 / Al 2 O 3 ) of the sample measured by inductively coupled plasma atomic emission spectrometry (ICP) was 0.86, the silicon-aluminum molar ratio (SiO 2 / Al 2 O 3 ) was 0.23, and the chemical composition of the zeolite was (Al 0.51 P 0.43 Si 0.06 )O 2 ·0.11R.

[0185] Table 7

[0186]

[0187]

[0188] After calcination at 550 °C for 6 hours, the specific surface area of the obtained sample was 509 m 2 / g, and the micropore volume was 0.20 cm 3 / g, and the total pore volume is 0.33 cm 3 / g. The total acid amount of the sample measured by NH 3 -TPD is 1542 μmol / g.

[0189] Example 8

[0190] Mix 32.21 g of deionized water, 19.99 g of methyltriethylammonium hydroxide solution (containing 40 wt% of methyltriethylammonium hydroxide), 5.371 g of pseudo-boehmite (containing Al 2 O 3 67.0 wt%), 6.10 g of phosphoric acid (containing H 3 PO 4 85 wt%) and 1.33 g of silica sol (containing SiO 2 40 wt%) evenly, stir at room temperature for 3 hours to obtain a mixture. The pH value of the mixture is 7.1, and the final material ratio (molar ratio) is:

[0191] P 2 O 5 / Al 2 O 3 = 0.75

[0192] SiO 2 / Al 2 O 3 = 0.25

[0193] R / Al 2 O 3 = 1.70

[0194] H 2 O / Al 2 O 3 = 75

[0195] Load the mixture into a stainless steel autoclave and crystallize it by rotation at 170 °C for 4 days. After crystallization, centrifuge and wash three times, and dry in an oven at 110 °C. The XRD spectral data of the obtained sample are shown in Table 8, which is a symbiotic zeolite of LEV and CHA type SAPO-35 / SAPO-34. Among them, the SAPO-35 zeolite accounts for 55 wt% in the symbiotic zeolite of SAPO-35 / SAPO-34. The phosphorus-aluminum molar ratio (P 2 O 5 / Al 2 O 3 ) of the sample measured by inductively coupled plasma atomic emission spectrometry (ICP) is 0.75, the silicon-aluminum molar ratio (SiO 2 / Al 2 O 3 ) is 0.19, and the chemical composition of the zeolite is (Al 0.54 P0.41 Si 0.05 )O 2 ·0.11R。

[0196] Table 8

[0197]

[0198]

[0199] The specific surface area of the sample obtained after calcination at 550 °C for 6 hours is 507 m 2 / g, the micropore volume is 0.22 cm 3 / g, and the total pore volume is 0.31 cm 3 / g. The total acid amount of the sample by NH 3 -TPD test is 1787 μmol / g.

[0200] Example 9

[0201] 34.77 g of deionized water, 20.85 g of methyltriethylammonium hydroxide solution (containing 40 wt% of methyltriethylammonium hydroxide), 5.014 g of pseudo-boehmite (containing Al 2 O 3 67.0 wt%), 9.12 g of phosphoric acid (containing H 3 PO 4 85 wt%) and 0.25 g of silica sol (containing SiO 2 40 wt%) were mixed evenly and stirred at room temperature for 3 hours to obtain a mixture. The pH value of the mixture is 6.7, and the final material ratio (molar ratio) is:

[0202] P 2 O 5 / Al 2 O 3 = 1.20

[0203] SiO 2 / Al 2 O 3 = 0.05

[0204] R / Al 2 O 3 = 1.90

[0205] H 2 O / Al 2 O 3 = 85

[0206] The mixture was charged into a stainless-steel reactor and crystallized by rotation at 175 °C for 4 days. After crystallization, it was centrifuged and washed three times, and then dried in an oven at 110 °C. The XRD spectrum data of the sample are shown in Table 9, which is a symbiotic zeolite of SAPO-35 / SAPO-34 with LEV and CHA structures. Among them, the SAPO-35 zeolite accounts for 65 wt% in the SAPO-35 / SAPO-34 symbiotic zeolite. The phosphorus-aluminum molar ratio (P 2 O 5 / Al 2 O 3 ) of the sample was measured by inductively coupled plasma atomic emission spectrometry (ICP) to be 1.18, and the silicon-aluminum molar ratio (SiO 2 / Al 2 O 3 ) was 0.06. The chemical composition of the zeolite was (Al 0.52 P 0.45 Si 0.03 )O 2 ·0.11R.

[0207] Table 9

[0208]

[0209]

[0210] After calcination at 550 °C for 6 hours, the specific surface area of the sample was 502 m 2 / g, the micropore volume was 0.20 cm 3 / g, and the total pore volume was 0.30 cm 3 / g. The total acid amount of the sample by NH 3 -TPD test was 1448 μmol / g.

[0211] Example 10

[0212] 35.99 g of deionized water, 26.54 g of methyltriethylammonium hydroxide solution (containing 40 wt% of methyltriethylammonium hydroxide), 5.271 g of pseudo-boehmite (containing 67.0 wt% of Al 2 O 3 ), 6.79 g of phosphoric acid (containing 85 wt% of H 3 PO 4 ) and 0.42 g of silica sol (containing 40 wt% of SiO 2 ) were mixed evenly and stirred at room temperature for 3 hours to obtain a mixture. The pH value of the mixture was 6.8, and the final material ratio (molar ratio) was:

[0213] P 2 O 5 / Al 2 O 3= 0.85

[0214] SiO 2 / Al 2 O 3 = 0.08

[0215] R / Al 2 O 3 = 2.30

[0216] H 2 H O / Al 2 O 3 = 88

[0217] The mixture was charged into a stainless-steel autoclave and crystallized by rotation at 185 °C for 3 days. After crystallization, it was centrifuged and washed three times, and then dried in an oven at 110 °C to obtain the XRD spectral data of the sample as shown in Table 10, which was a symbiotic zeolite of LEV and CHA type SAPO-35 / SAPO-34. Among them, the SAPO-35 zeolite accounted for 70 wt% in the symbiotic zeolite of SAPO-35 / SAPO-34. The phosphorus-aluminum molar ratio (P 2 O 5 / Al 2 O 3 ) of the sample was measured by inductively coupled plasma atomic emission spectrometry (ICP) to be 0.86, the silicon-aluminum molar ratio (SiO 2 / Al 2 O 3 ) was 0.09, and the chemical composition of the zeolite was (Al 0.52 P 0.45 Si 0.03 )O 2 ·0.11R.

[0218] Table 10

[0219]

[0220] After calcination at 550 °C for 6 hours, the specific surface area of the sample was 529 m 2 / g, the micropore pore volume was 0.23 cm 3 / g, and the total pore volume was 0.34 cm 3 / g. The total acid amount of the sample measured by NH 3 -TPD was 1416 μmol / g.

[0221] Examples 11 - 20

[0222] The zeolites synthesized in Examples 1 - 10 were respectively calcined at 550 °C for 6 hours to obtain H-type SAPO-35 / SAPO-34 zeolites.

[0223] Take the above-mentioned calcined H-type SAPO-35 / SAPO-34 molecular sieve powder sample, crush it, and sieve out 1.0 g of the particle size fraction of 20-40 meshes and put it into a fixed-bed reactor for methanol conversion reaction. The reaction conditions are as follows: the reaction temperature is 450-480 °C, the reaction pressure is atmospheric pressure, and the methanol weight hourly space velocity is 0.75-3 h -1 , and the specific reaction conditions of each example are shown in Table 11. A Shimadzu GC-2014 gas chromatograph was used to analyze the products, catalyst activity and product selectivity, as shown in Table 11.

[0224] Table 11 Performance results of catalysts in Examples 11-20

[0225]

[0226] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A SAPO-35 / SAPO-34 coexisting molecular sieve, characterized in that, The SAPO-35 / SAPO-34 symbiotic molecular sieve has the following anhydrous chemical composition: (Al x P y Si z )O 2 ·mR, where R is the template methyltriethylammonium hydroxide, x = 0.35 - 0.60, y = 0.30 - 0.50, z = 0.005 - 0.20, x + y + z = 1, m is the molar fraction of R, and m = 0.05 - 0.12; the molecular sieve has an X-ray diffraction pattern including the LEV structure of SAPO-35 molecular sieve and the CHA structure of SAPO-34 molecular sieve as shown in the following table, a: ±0.30°, b: varying with 2θ.

2. The SAPO-35 / SAPO-34 coexisting molecular sieve according to claim 1, wherein, in the SAPO-35 / SAPO-34 coexisting molecular sieve, the peak intensity of the characteristic peak belonging to the LEV structure of SAPO-35 molecular sieve is higher than the peak intensity of the characteristic peak belonging to the CHA structure of SAPO-34 molecular sieve.

3. The SAPO-35 / SAPO-34 coexisting molecular sieve according to claim 2, wherein, the SAPO-35 molecular sieve accounts for 50 - 80% by weight in the SAPO-35 / SAPO-34 coexisting molecular sieve.

4. The SAPO-35 / SAPO-34 coexisting molecular sieve according to claim 1, wherein, x = 0.38 - 0.57, y = 0.32 - 0.48, z = 0.01 - 0.15, x + y + z = 1, m = 0.06 - 0.

11.

5. A preparation method of the SAPO-35 / SAPO-34 coexisting molecular sieve according to any one of claims 1 - 4, characterized in that, the method includes: heating and crystallizing a mixture containing an aluminum source, a phosphorus source, a silicon source, methyltriethylammonium hydroxide and water, and post-treatment; Among them, the aluminum source is calculated as Al 2 O 3 ; the phosphorus source is calculated as P 2 O 5 ; the silicon source is calculated as SiO 2 ; methyltriethylammonium hydroxide R and water, with a molar ratio of Al 2 O 3 :P 2 O 5 :SiO 2 :R:H 2 O = 1:0.65~1.40:0.01~0.65:1.50~2.50:63~120.

6. The preparation method according to claim 5, wherein, The aluminum source is calculated as Al 2 O 3 ; the phosphorus source is calculated as P 2 O 5 ; the silicon source is calculated as SiO 2 ; methyltriethylammonium hydroxide R and water are in a molar ratio of Al 2 O 3 :P 2 O 5 :SiO 2 :R:H 2 O = 1:0.70~1.35:0.02~0.60:1.55~2.45:65~110; and / or the aluminum source is at least one selected from pseudoboehmite, alkoxyaluminum, aluminum salt, alumina and aluminum hydroxide; and / or the phosphorus source is at least one selected from phosphoric acid, ammonium hydrogen phosphate, ammonium dihydrogen phosphate and organic phosphides; and / or the silicon source is at least one selected from silica sol, silica gel and tetraethyl orthosilicate.

7. The preparation method according to claim 6, wherein, the aluminum source is pseudoboehmite; and / or the phosphorus source is phosphoric acid; and / or the silicon source is silica sol.

8. The preparation method according to claim 5, wherein, the pH value of the mixture is 6.5 - 9.0; and / or the mixture does not contain crystal seeds; and / or the crystallization conditions of the mixture include: crystallizing at 150 - 205 °C for 0.5 - 7 days; and / or the post-treatment includes separation, washing, drying and optionally calcination.

9. The preparation method according to claim 8, wherein, the crystallization conditions of the mixture include: crystallizing at 155 - 200 °C for 0.75 - 6 days.

10. The preparation method according to claim 8, wherein, the crystallization conditions of the mixture include: crystallizing at 160 - 195 °C for 0.75 - 5 days.

11. The SAPO-35 / SAPO-34 coexisting molecular sieve prepared by the preparation method according to any one of claims 5 - 10.

12. The molecular sieve according to claim 11, wherein, The SAPO-35 / SAPO-34 symbiotic molecular sieve has the following anhydrous chemical composition: (Al x P y Si z )O 2 ·mR, where R is the template methyltriethylammonium hydroxide, x = 0.35 to 0.60, y = 0.30 to 0.50, z = 0.005 to 0.20, x + y + z = 1, m is the molar fraction of R, and m = 0.05 to 0.

12.

13. The molecular sieve according to claim 12, wherein, The molecular sieve has an X-ray diffraction pattern including the LEV structure of SAPO-35 molecular sieve and the CHA structure of SAPO-34 molecular sieve as shown in the following table; and / or a: ±0.30°, b: varying with 2θ; In the SAPO-35 / SAPO-34 intergrown molecular sieve, the peak intensity of the characteristic peak belonging to the LEV structure of SAPO-35 molecular sieve is higher than that of the characteristic peak belonging to the CHA structure of SAPO-34 molecular sieve; and / or SAPO-35 molecular sieve accounts for 50 - 80% by weight in the SAPO-35 / SAPO-34 intergrown molecular sieve; and / or x = 0.38 - 0.57, y = 0.32 - 0.48, z = 0.01 - 0.15, x + y + z = 1, m = 0.06 - 0.11; and / or After calcination at 300 - 800 °C for 1 - 10 hours: The specific surface area of the SAPO-35 / SAPO-34 symbiotic molecular sieve is 450 to 650 m 2 / g; and / or The pore volume of the SAPO-35 / SAPO-34 intergrown molecular sieve is 0.20 to 0.60 cm 3 / g; and / or The micropore volume of the SAPO-35 / SAPO-34 symbiotic molecular sieve is 0.12~0.28 cm 3 / g; and / or The acid amount of the SAPO-35 / SAPO-34 intergrown molecular sieve is 1000 - 2200 μmol / g.

14. The molecular sieve according to claim 12, wherein, After calcination at 300 - 800 °C for 1 - 10 hours: The pore volume of the SAPO-35 / SAPO-34 symbiotic molecular sieve is 0.25 to 0.55 cm 3 / g; and / or The micropore volume of the SAPO-35 / SAPO-34 intergrown molecular sieve is 0.15 to 0.25 cm 3 / g; and / or The acid amount of the SAPO-35 / SAPO-34 intergrown molecular sieve is 1100 - 2000 μmol / g.

15. A molecular sieve composition comprising the SAPO-35 / SAPO-34 intergrown molecular sieve according to any one of claims 1 - 4 and 11 - 14 and a binder.

16. Use of the SAPO-35 / SAPO-34 intergrown molecular sieve according to any one of claims 1 - 4 and 11 - 14 or the molecular sieve composition according to claim 15 as a catalyst in the reaction for preparing olefins from oxides.

17. Use of the SAPO-35 / SAPO-34 intergrown molecular sieve according to any one of claims 1 - 4 and 11 - 14 or the molecular sieve composition according to claim 15 as a catalyst in the reaction for preparing ethylene and propylene by methanol conversion.

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