A molecular sieve composition, its preparation method and application

Abstract

This invention discloses a molecular sieve composition, its preparation method, and its applications. The molecular sieve composition of this invention, by weight, comprises the following components: a) 10–80 parts of micron-nano dual-scale FAU molecular sieve; b) 10–80 parts of binder; c) 0–10 parts of modifier; wherein the modifier is selected from at least one of Group IIB, Group VIB, and Group VIII metal oxides; the total pore volume of the micron-nano dual-scale FAU molecular sieve is 0.80–1.20 cm³. 3 / g. The molecular sieve composition of the present invention uses micron-nano FAU molecular sieves as the main active component, and mixes them with binders and optional modifiers to form a composition. It is used in the industrial production of removing sulfur-containing compounds from olefin raw materials through adsorption purification, and has a high adsorption capacity and significantly reduced adsorption exothermics.

Description

Technical Field

[0001] This invention belongs to the field of olefin raw material adsorbents, specifically relating to a molecular sieve composition, its preparation method, and its application. Background Technology

[0002] Low-carbon olefins (ethylene, propylene, and butene) are crucial basic chemical raw materials. However, due to the influence of raw material sources, low-carbon olefins produced by the MTO process often contain trace amounts of methanol, dimethyl ether, propionaldehyde, water, and other oxygen-containing organic compounds. The presence of these polar impurities poses a significant challenge to the stable operation of downstream olefin processing units such as polyolefins and olefin disproportionation, and can even lead to catalyst poisoning and unit shutdown. Therefore, developing efficient methods for removing oxygen-containing compound impurities from MTO olefins is of great significance for ensuring the stable operation of olefin production and processing in coal chemical routes.

[0003] Porous materials such as silica gel, alumina, and molecular sieves are commonly used as adsorbents. CN1559680A discloses an adsorbent comprising seven components: ZnO, Ni2O, CaAl2O4, TiO2, CoO, MoO, and Al2O3, used as a solid desulfurization catalyst for removing toxic and harmful substances such as sulfides, sulfur oxides, and sulfides from natural gas and flue gas. CN105107459B discloses a method for preparing a desulfurization adsorbent, mainly by processing walnut shells to obtain biomass activated carbon with a rich pore structure, which can be used as an adsorbent to simultaneously remove H2S, COS, and CS2. CN101970106A discloses a desulfurization material comprising one or more nickel compounds, a zinc oxide support material, and one or more alkali metal compounds, which can be used for gas desulfurization. CN1868572A discloses an iron-based composite metal oxide catalyst for direct oxidative desulfurization. The catalyst composition includes iron oxide, alumina, titanium oxide, zinc oxide, and vanadium oxide.

[0004] In summary, although existing technologies have reported some adsorbents and corresponding purification methods for desulfurization of gaseous feedstocks, in specific applications, there are problems such as low adsorption purification depth, low adsorption capacity, and high adsorption exothermics. Summary of the Invention

[0005] Based on the problems of low adsorption purification depth, limited adsorption capacity, poor adsorption selectivity, and large adsorption heat release in existing molecular sieve adsorbents, which lead to carbon deposition and deactivation of the adsorbent, this invention provides a molecular sieve composition, its preparation method, and its application. When used to adsorb sulfur-containing compound impurities in olefin feedstocks, this molecular sieve composition has a high adsorption capacity, significantly reduced adsorption heat release (bed temperature rise), and significantly improved adsorbent stability.

[0006] The first aspect of the present invention provides a molecular sieve composition comprising, by weight, the following components:

[0007] a) 10–80 parts of micron-nano dual-scale FAU molecular sieve;

[0008] b) 10–80 parts adhesive;

[0009] c) 0-10 parts of the modifier;

[0010] The modifier is selected from at least one group of Group IIB, Group VIB, and Group VIII metal oxides; the total pore volume of the micron-nano dual-scale FAU molecular sieve is 0.80–1.20 cm³. 3 / g.

[0011] In the above technical solution, the total pore volume of the micron-nano dual-scale FAU molecular sieve is 0.80–1.20 cm³. 3 / g, for example, but not limited to, 0.80cm 3 / g, 0.85cm 3 / g, 0.89cm 3 / g, 0.90cm 3 / g, 0.92cm 3 / g, 0.94cm 3 / g, 0.96cm 3 / g, 0.98cm 3 / g, 1.00cm 3 / g, 1.20cm 3 / g, and any value within the range formed by any two of these values.

[0012] In the above technical solution, the micron-nano dual-scale X molecular sieve is different from a mechanical mixture of micron-X molecular sieve and nano-X molecular sieve.

[0013] In the above technical solution, preferably, the molecular sieve composition comprises the following components in parts by weight:

[0014] a) 20–80 parts of micron-nano dual-scale FAU molecular sieve, preferably 25–50 parts;

[0015] b) 20 to 80 parts of adhesive, preferably 50 to 75 parts;

[0016] c) 1 to 10 parts of the modifier, preferably 2 to 8 parts;

[0017] The modifier is selected from at least one group of Group IIB, Group VIB and Group VIII metal oxides. The binder is calculated as an oxide.

[0018] In the above technical solution, the molecular sieve composition includes, by weight, 20 to 80 parts of micron-nano dual-scale FAU molecular sieve, for example, but not limited to, 20 parts, 30 parts, 40 parts, 50 parts, 60 parts, 70 parts, 80 parts, and any value within the range formed by any two of these values.

[0019] In the above technical solution, the molecular sieve composition includes 20 to 80 parts of binder by weight, for example, but not limited to, 20 parts, 30 parts, 40 parts, 50 parts, 60 parts, 70 parts, 80 parts, and any value within the range formed by any two of these values.

[0020] In the above technical solution, the molecular sieve composition includes 1 to 10 parts of modifier by weight, such as, but not limited to, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, and any value within the range formed by any two of these values.

[0021] In the above technical solution, the micron-nano dual-scale FAU molecular sieve has a crystal size of 10-200 nanometers, preferably 20-100 nanometers, for the nano FAU molecular sieve and a crystal size of 1.0-10.0 micrometers, preferably 2.0-5.0 micrometers, for the micron FAU molecular sieve.

[0022] In the above technical solution, the SiO2 / Al2O3 molar ratio of the micron-nano dual-scale FAU molecular sieve is 2.0 to 10.0.

[0023] In the above technical solution, the mass ratio of micron-nano dual-scale FAU molecular sieve to nano FAU molecular sieve is 1:3 to 3:1, preferably 1:3 to 2:3.

[0024] In the above technical solution, the micron-nano dual-scale FAU molecular sieve is selected from at least one of NaX, LiX, KX, NH4X, HX, MgX, CaX, NaY, LiY, KY, NH4Y, HY, MgY, and CaY molecular sieves. The cations in the molecular sieve can be directly derived from the raw materials used in preparing the molecular sieve powder, such as an alkali source, or from ion exchange after the molecular sieve powder preparation is completed.

[0025] In the above technical solution, the binder is selected from at least one of alumina, boehmite, kaolin, and montmorillonite.

[0026] In the above technical solution, preferably, the modifier is selected from at least one of Cr2O3, MnO2, Fe2O3, Co2O3, Ni2O, CuO or ZnO.

[0027] A second aspect of the present invention provides a method for preparing the above-mentioned molecular sieve composition, comprising the following steps:

[0028] Micron-nano dual-scale FAU molecular sieves, binders, and modifiers are mixed, shaped, dried, and calcined to obtain the molecular sieve composition.

[0029] In the above technical solution, the preparation method of the micron-nano dual-scale FAU molecular sieve includes:

[0030] (I) Water, silicon source, alkali source and aluminum source are mixed and crystallized I to obtain micron-sized FAU molecular sieve synthesis mother liquor;

[0031] (II) Water, silicon source, alkali source and aluminum source are mixed and aged to obtain the mother liquor for the synthesis of nano-FAU molecular sieve;

[0032] (III) Add the synthetic mother liquor of nano-FAU molecular sieve obtained in step (II) to the synthetic mother liquor of micron-FAU molecular sieve obtained in step (I), crystallize it in step II, and dry it to obtain micron-nano dual-scale FAU molecular sieve.

[0033] In the above technical solution, in step (I), the crystallization conditions include: the crystallization temperature is 80-120℃ and the crystallization time is 2-60 hours.

[0034] In the above technical solution, in step (II), the aging conditions include: an aging temperature of 20 to 60°C and an aging time of 2 to 60 hours.

[0035] In the above technical solution, in step (III), the crystallization II conditions include: crystallization II temperature of 40 to 80°C and crystallization II time of 2 to 120 hours.

[0036] In the above technical solution, in step (I), the molar ratio of silicon source (SiO2), aluminum source (Al2O3), alkali source (M2O), and water is 1.0–12.0:SiO2:1.0Al2O3:1.0–10.0M2O:100.0–300.0H2O. For example, the alkali source NH4OH is calculated as (NH)2O, TMAH as (TMA)2O, and TEAH as (TEA)2O.

[0037] In the above technical solution, in step (II), the molar ratio of silicon source (SiO2), aluminum source (Al2O3), alkali source (M2O), and water is 1.0-25.0 SiO2:1.0 Al2O3:1.0-25.0 M2O:100.0-500.0 H2O.

[0038] In the above technical solution, in step (III), the molar ratio of SiO2 in the mother liquor for synthesizing micron-sized FAU molecular sieves to that in the mother liquor for synthesizing nano-sized FAU molecular sieves is 0.1 to 10.0.

[0039] In the above technical solution, in steps (I) and (II), the silicon source is independently selected from at least one of sodium silicate, water glass, silica sol, white carbon black, and tetraethyl orthosilicate; the aluminum source is independently selected from at least one of aluminum nitrate, aluminum sulfate, aluminum powder, aluminum sol, sodium aluminate, aluminum isopropoxide, and tert-butylaluminum; and the alkali source is independently selected from at least one of sodium hydroxide, potassium hydroxide, ammonium hydroxide (NH4OH), tetramethylammonium hydroxide (TMAH), and tetraethylammonium hydroxide (TEAH).

[0040] In the above technical solution, in step (III), after crystallization II is completed, the solid is separated from the mother liquor. The solid is washed with deionized water and dried to obtain micron-nano dual-scale FAU molecular sieve. The drying conditions include: drying temperature of 80-170℃ and drying time of 12-75 hours.

[0041] In the above technical solution, after drying in step (III), ion exchange can be used to obtain micron-nano dual-scale X molecular sieves with different cations, such as at least one of NaX, LiX, KX, NH4X, HX, MgX, and CaX molecular sieves, preferably at least one of NaX, KX, MgX, and CaX molecular sieves.

[0042] In the above technical solution, the dry basis ratio of the micron-nano dual-scale FAU molecular sieve, binder, and modifier is 10-80:10-80:0-10, preferably 20-80:20-80:1-10. Here, the dry basis ratio refers to the weight ratio of each substance without moisture, and the binder and modifier are calculated as oxides.

[0043] In the above technical solution, the molding method can be any one of extrusion molding, ball rolling molding, or tablet molding, with extrusion molding being preferred. After molding, the mixture is dried and calcined to obtain the molecular sieve composition. The drying temperature is 30–120°C, and the drying time is 12–72 hours. The calcination conditions include a calcination temperature of 300–600°C and a calcination time of 1–5 hours.

[0044] A third aspect of the present invention provides a method for removing sulfur-containing compounds from olefin feedstocks.

[0045] In the above technical solution, the method includes reacting the olefin raw material with the above molecular sieve composition to obtain the purified olefin raw material, wherein the sulfur-containing compound in the olefin raw material is selected from at least one of organic thiols, thioethers (preferably methyl sulfide), and thiophene.

[0046] In the above technical solution, the olefin raw material is selected from at least one of ethylene, propylene, and butene; preferably, the volume concentration of sulfur-containing compounds in the olefin raw material is 10 to 1000 ppm, more preferably 50 to 200 ppm.

[0047] In the above technical solution, the reaction conditions include: a temperature of 10–60℃, a pressure of 0–4.0 MPa, and an ethylene feedstock volume hourly space velocity of 500–10000 h⁻¹. -1 .

[0048] Compared with the prior art, the present invention has the following beneficial technical effects:

[0049] This invention provides a molecular sieve composition comprising a micron-nano dual-scale FAU molecular sieve, a binder, and an optional modifier; wherein the modifier is selected from at least one group of Group IIB, Group VIB, and Group VIII metal oxides; preferably, the total pore volume of the micron-nano dual-scale FAU molecular sieve is 0.80–1.20 cm³. 3 / g. The inventors have discovered that using the composition containing micron-nano dual-scale FAU molecular sieves of this invention as an adsorbent for the adsorption and purification of sulfur-containing compounds from olefin feedstocks can significantly improve adsorption capacity and accuracy, and enhance adsorbent stability.

[0050] The composition of the present invention containing micron-nano dual-scale FAU molecular sieve has a higher adsorption capacity for sulfur-containing compounds (such as dimethyl sulfide) when purifying ethylene feedstock. In addition, the temperature rise change is significantly reduced when the feedstock passes through the adsorbent bed, indicating that the composition containing micron-nano dual-scale FAU molecular sieve has a lower heat release during the adsorption of sulfur-containing compound impurities, which reduces adsorbent carbon deposition and slows down the deactivation of adsorbent pores caused by this.

[0051] The molecular sieve composition of the present invention is used to adsorb dimethyl sulfide in ethylene feedstock, with a breakthrough adsorption capacity of up to 63 mg / g and an adsorbent bed temperature rise of 1.8℃. Attached Figure Description

[0052] Figure 1 These are the XRD patterns of the micron-nano dual-scale X-ray molecular sieve obtained in Example 1 and the micron-X-ray molecular sieve obtained in Comparative Example 1.

[0053] Figure 2 This is a SEM image of the micron-nano dual-scale X-ray molecular sieve obtained in Example 1;

[0054] Figure 3 The image shows the SEM image of the micron-X molecular sieve obtained in Comparative Example 1.

[0055] Figure 4This is a photograph of the molecular sieve composition of Example 1;

[0056] Figure 5 This is the XRD pattern of the micron-nano dual-scale Y molecular sieve obtained in Example 8. Detailed Implementation

[0057] The technical solution of the present invention will be further illustrated below through embodiments, but the scope of protection of the present invention is not limited to the embodiments. In the present invention, wt% is a mass fraction.

[0058] In this invention, the testing conditions for XRD and scanning electron microscopy are as follows:

[0059] XRD testing conditions: Molecular sieve crystal phase analysis was performed using a Rigaku-Ultima X-ray diffractometer (Japan). CuKα radiation was used, with a wavelength λ = 0.15432 nm. The X-ray diffraction pattern scanning range was 2θ5-50°, and the scanning speed was 10° / min.

[0060] SEM testing conditions: A Hitachi S4800 field emission scanning electron microscope (SEM) was used for testing.

[0061] In this invention, the SiO2 / Al2O3 molar ratio in the molecular sieve is determined by XRF.

[0062] In this invention, the molecular sieve pore volume is calculated using a nitrogen adsorption-desorption isotherm.

[0063] In the embodiments and comparative examples of this invention, the formula for calculating the adsorption capacity of sulfur-containing compounds (taking methyl sulfide as an example) is as follows:

[0064]

[0065] q represents the breakthrough adsorption capacity (mg / g), defined as the time when the outlet volume concentration of dimethyl sulfide reaches 1 ppm as the breakthrough time, and the corresponding adsorption amount as the breakthrough adsorption capacity; M represents the molecular weight of dimethyl sulfide; t represents time (min); Q represents the adsorbent flow rate (mL / min); P represents the pressure (Pa); and R represents the ideal gas constant (8.314 J·mol⁻¹). 1 .K- 1 T is the temperature (K); ms is the mass of the adsorbent (g); Cs and Ct are the volume concentrations (ppm) of dimethyl sulfide impurities in the ethylene feedstock and the volume concentrations (ppm) of dimethyl sulfide impurities at the adsorbent bed outlet, respectively.

[0066]

Example 1

[0067] (1) The micron-nano dual-scale X-molecule sieve was prepared according to the following steps:

[0068] I: In a crystallization reactor, a certain amount of silicon source, aluminum source, and alkali source are weighed out and mixed evenly with deionized water according to the molar ratio SiO2:Al2O3:Na2O:H2O=10.0:1.0:6.0:250.0, and then sealed. The mixture is then crystallized at 100℃ for 12 hours. After cooling, the mother liquor for the synthesis of micron-X molecular sieve is obtained.

[0069] II: In a crystallization reactor, a certain amount of silicon source, aluminum source, and alkali source, namely silica sol, aluminum sol, and sodium hydroxide, are weighed and mixed with deionized water according to the molar ratio SiO2:Al2O3:Na2O:H2O=24.0:1.0:25.0:500.0. The mixture is then sealed and aged at 40℃ for 24 hours. After cooling, the mother liquor for the synthesis of nano X molecular sieve is obtained.

[0070] III: Following a 1:1 molar ratio of SiO2 in the mother liquor for synthesizing micron-X molecular sieves to SiO2 in the mother liquor for synthesizing nano-X molecular sieves, the mother liquor for synthesizing nano-X molecular sieves obtained after aging in step II was added to the mother liquor for synthesizing micron-X molecular sieves obtained after crystallization in step I. After stirring evenly, the mixture was sealed and crystallized at 60°C for 24 hours. After crystallization was completed, the solid was separated from the mother liquor by centrifugation. The solid was washed with deionized water and dried to obtain micron-nano dual-scale X molecular sieves.

[0071] The XRD pattern of the sample obtained in Example 1 is as follows: Figure 1 As shown in b, the scanning electron microscope (SEM) image is as follows: Figure 2 As shown in the figure. In this example, the weight ratio of micron-X molecular sieve to nano-X molecular sieve in the micron-nano dual-scale X molecular sieve is approximately 1:3.

[0072] (2) Preparation of compositions containing micron-nano dual-scale X-zeolites:

[0073] The obtained micron-nano dual-scale X-zeolite, pseudoboehmite powder, and copper nitrate salt were weighed separately to ensure that the dry basis ratio of the molecular sieve, the Al2O3 corresponding to the pseudoboehmite, and the CuO corresponding to the copper nitrate was 30:64:6. After mixing, the mixture was extruded into thin strips with a diameter of 1.8 mm. The extruded strips were dried at 80°C for 24 hours and calcined at 500°C for 5 hours to obtain a composition containing micron-nano dual-scale X-zeolite. The resulting sample is shown in the image below. Figure 4 As shown in the image.

[0074] The obtained composition containing micron-nano dual-scale X-zeolite was crushed into particles of approximately 2 mm and placed into a quartz reaction tube with an inner diameter of 40 mm. Ethylene gas containing 50 ppm (volume concentration, the same below) of dimethyl sulfide was introduced into the reaction tube and allowed to react in the adsorption bed. The reaction temperature was 40 °C, the reaction system pressure was 1.0 atm, and the gas hourly space velocity was 6000 h⁻¹. 1 Ethylene feedstock was purified by adsorption under the specified conditions. The reaction results are shown in Table 3.

[0075]

Example 2

[0076] (1) The micron-nano dual-scale X-molecule sieve was prepared according to the following steps:

[0077] I: In a crystallization reactor, a certain amount of silicon source, aluminum source, and alkali source are weighed out and mixed with deionized water according to the molar ratio SiO2:Al2O3:Na2O:H2O=10.0:1.0:6.0:250.0, and then sealed. The mixture is then crystallized at 100℃ for 6 hours. After cooling, the mother liquor for the synthesis of micron-X molecular sieve is obtained.

[0078] II: In a crystallization reactor, a certain amount of silicon source, aluminum source, and alkali source, namely silica sol, aluminum sol, and sodium hydroxide, are weighed and mixed with deionized water according to the molar ratio SiO2:Al2O3:Na2O:H2O=24.0:1.0:25.0:500.0. The mixture is then sealed and aged at 40℃ for 24 hours. After cooling, the mother liquor for the synthesis of nano X molecular sieve is obtained.

[0079] III: Following a 1:1 molar ratio of SiO2 in the mother liquor for synthesizing micron-X molecular sieves to SiO2 in the mother liquor for synthesizing nano-X molecular sieves, the mother liquor for synthesizing nano-X molecular sieves obtained after aging in step II was added to the mother liquor for synthesizing micron-X molecular sieves obtained after crystallization in step I. After stirring evenly, the mixture was sealed and crystallized at 60°C for 24 hours. After crystallization was completed, the solid was separated from the mother liquor by centrifugation. The solid was washed with deionized water and dried to obtain micron-nano dual-scale X molecular sieves.

[0080] In this example, the weight ratio of micron-X molecular sieve to nano-X molecular sieve in the micron-nano dual-scale X molecular sieve is approximately 1:5.

[0081] The XRD pattern of the obtained sample is similar to Figure 1 Similar to b, the scanning electron microscope (SEM) images are... Figure 2 similar.

[0082] (2) Preparation of compositions containing micron-nano dual-scale X-zeolites:

[0083] Weigh the obtained micron-nano dual-scale X molecular sieve, pseudoboehmite powder, and copper nitrate salt separately to ensure that the dry basis ratio of the molecular sieve, the Al2O3 corresponding to pseudoboehmite, and the CuO corresponding to copper nitrate is 30:64:6. After mixing, prepare thin strips with a diameter of 1.8 mm by extrusion molding. Dry the extruded strips at 80°C for 24 hours and calcine them at 500°C for 5 hours to obtain a composition containing micron-nano dual-scale X molecular sieve.

[0084] The obtained composition containing micron-nano dual-scale X-zeolite was broken into fine strips of approximately 2 mm and packed into a quartz reaction tube with an inner diameter of 40 mm. Ethylene gas containing 50 ppm dimethyl sulfide was introduced into the reaction tube and allowed to react in the adsorption bed. The reaction temperature was 40 °C, the reaction system pressure was 1.0 atm, and the gas hourly space velocity was 6000 h⁻¹. 1 Ethylene feedstock was purified by adsorption under the specified conditions. The reaction results are shown in Table 3.

[0085]

Example 3

[0086] (1) The micron-nano dual-scale X-molecule sieve was prepared according to the following steps:

[0087] I: In a crystallization reactor, a certain amount of silicon source, aluminum source, and alkali source are weighed out and mixed evenly with deionized water according to the molar ratio SiO2:Al2O3:Na2O:H2O=10.0:1.0:6.0:250.0, and then sealed. The mixture is then crystallized at 100℃ for 24 hours. After cooling, the mother liquor for the synthesis of micron-X molecular sieve is obtained.

[0088] II: In a crystallization reactor, a certain amount of silicon source, aluminum source, and alkali source, namely silica sol, aluminum sol, and sodium hydroxide, are weighed and mixed with deionized water according to the molar ratio SiO2:Al2O3:Na2O:H2O=24.0:1.0:25.0:500.0. The mixture is then sealed and aged at 40℃ for 24 hours. After cooling, the mother liquor for the synthesis of nano X molecular sieve is obtained.

[0089] III: Following a 1:1 molar ratio of SiO2 in the mother liquor for synthesizing micron-X molecular sieves to SiO2 in the mother liquor for synthesizing nano-X molecular sieves, the mother liquor for synthesizing nano-X molecular sieves obtained after aging in step II was added to the mother liquor for synthesizing micron-X molecular sieves obtained after crystallization in step I. After stirring evenly, the mixture was sealed and crystallized at 60°C for 24 hours. After crystallization was completed, the solid was separated from the mother liquor by centrifugation. The solid was washed with deionized water and dried to obtain micron-nano dual-scale X molecular sieves.

[0090] In this example, the weight ratio of micron-X molecular sieve to nano-X molecular sieve in the micron-nano dual-scale X molecular sieve is approximately 2:3.

[0091] The XRD pattern of the obtained sample is similar to Figure 1 Similar to b, the scanning electron microscope (SEM) images are... Figure 2 similar.

[0092] (2) Preparation of compositions containing micron-nano dual-scale X-zeolites:

[0093] Weigh the obtained micron-nano dual-scale X molecular sieve, pseudoboehmite powder, and copper nitrate salt separately to ensure that the dry basis ratio of the molecular sieve, the Al2O3 corresponding to pseudoboehmite, and the CuO corresponding to copper nitrate is 30:64:6. After mixing, prepare thin strips with a diameter of 1.8 mm by extrusion molding. Dry the extruded strips at 80°C for 24 hours and calcine them at 500°C for 5 hours to obtain a composition containing micron-nano dual-scale X molecular sieve.

[0094] The obtained composition containing micron-nano dual-scale X-zeolite was broken into fine strips of approximately 2 mm and packed into a quartz reaction tube with an inner diameter of 40 mm. Ethylene gas containing 50 ppm dimethyl sulfide was introduced into the reaction tube and allowed to react in the adsorption bed. The reaction temperature was 40 °C, the reaction system pressure was 1.0 atm, and the gas hourly space velocity was 6000 h⁻¹. 1 Ethylene feedstock was purified by adsorption under the specified conditions. The reaction results are shown in Table 3.

[0095]

Example 4

[0096] (1) The micron-nano dual-scale X molecular sieve was prepared according to [Example 1].

[0097] (2) Preparation of compositions containing micron-nano dual-scale X molecular sieves.

[0098] Micron-nano dual-scale X-zeolite, pseudoboehmite powder, and copper nitrate salt were weighed separately to ensure that the dry basis ratio of the molecular sieve, the Al2O3 corresponding to pseudoboehmite, and the CuO corresponding to copper nitrate was 40:54:6. After mixing, the mixture was extruded into thin strips with a diameter of 1.8 mm. The extruded strips were dried at 80°C for 24 hours and calcined at 500°C for 5 hours to obtain a composition containing micron-nano dual-scale X-zeolite.

[0099] The obtained composition containing micron-nano dual-scale X-zeolite was broken into fine strips of approximately 2 mm and packed into a quartz reaction tube with an inner diameter of 40 mm. Ethylene gas containing 50 ppm dimethyl sulfide was introduced into the reaction tube and allowed to react in the adsorption bed. The reaction temperature was 40 °C, the reaction system pressure was 1.0 atm, and the gas hourly space velocity was 6000 h⁻¹. 1 Ethylene feedstock was purified by adsorption under the specified conditions. The reaction results are shown in Table 3.

[0100]

Example 5

[0101] (1) The micron-nano dual-scale X molecular sieve was prepared according to [Example 1].

[0102] (2) Preparation of compositions containing micron-nano dual-scale X molecular sieves.

[0103] Micron-nano dual-scale X-zeolite, pseudoboehmite powder, and zinc nitrate were weighed separately to ensure that the dry basis ratio of the molecular sieve, the Al2O3 corresponding to pseudoboehmite, and the ZnO corresponding to zinc nitrate was 30:64:6. After mixing, the mixture was extruded into thin strips with a diameter of 1.8 mm. The extruded strips were then calcined at 500°C for 5 hours to obtain a composition containing micron-nano dual-scale X-zeolite.

[0104] The obtained composition containing micron-nano dual-scale X-zeolite was broken into fine strips of approximately 2 mm and packed into a quartz reaction tube with an inner diameter of 40 mm. Ethylene gas containing 50 ppm dimethyl sulfide was introduced into the reaction tube and allowed to react in the adsorption bed. The reaction temperature was 40 °C, the reaction system pressure was 1.0 atm, and the gas hourly space velocity was 6000 h⁻¹. 1 Ethylene feedstock was purified by adsorption under the specified conditions. The reaction results are shown in Table 3.

[0105]

Example 6

[0106] (1) Micron-nano dual-scale X-type molecular sieves were prepared according to [Example 1]:

[0107] (2) Preparation of compositions containing micron-nano dual-scale X-zeolites:

[0108] Weigh out micron-nano dual-scale X molecular sieve and pseudoboehmite powder separately, ensuring that the dry basis ratio of Al2O3 corresponding to the molecular sieve and pseudoboehmite is 33:67. After mixing, prepare thin strips with a diameter of 1.8 mm by extrusion molding. Calcine the extruded strips at 500℃ for 5 hours to obtain a composition containing micron-nano dual-scale X molecular sieve.

[0109] The obtained composition containing micron-nano dual-scale X-zeolite was broken into fine strips of approximately 2 mm and packed into a quartz reaction tube with an inner diameter of 40 mm. Ethylene gas containing 50 ppm dimethyl sulfide was introduced into the reaction tube and allowed to react in the adsorption bed. The reaction temperature was 40 °C, the reaction system pressure was 1.0 atm, and the gas hourly space velocity was 6000 h⁻¹. 1 Ethylene feedstock was purified by adsorption under the specified conditions. The reaction results are shown in Table 3.

[0110]

Example 7

[0111] (1) Micron-nano dual-scale X-type molecular sieves were prepared according to [Example 1]:

[0112] (2) Preparation of compositions containing micron-nano dual-scale X-zeolites:

[0113] Weigh out the micron-nano dual-scale X-zeolite, pseudoboehmite powder, and nitric acid respectively.

[0114] Salt was used to ensure that the dry basis ratio of molecular sieve, Al2O3 corresponding to pseudoboehmite, and Ni2O corresponding to nickel nitrate was 30:64:6. After mixing, the mixture was prepared into thin strips with a diameter of 1.8 mm by extrusion molding. The extruded strips were then calcined at 500°C for 5 hours to obtain a composition containing micron-nano dual-scale X molecular sieve.

[0115] The obtained composition containing micron-nano dual-scale X-zeolite was broken into fine strips of approximately 2 mm and packed into a quartz reaction tube with an inner diameter of 40 mm. Ethylene gas containing 50 ppm dimethyl sulfide was introduced into the reaction tube and allowed to react in the adsorption bed. The reaction temperature was 40 °C, the reaction system pressure was 1.0 atm, and the gas hourly space velocity was 6000 h⁻¹. 1 Ethylene feedstock was purified by adsorption under the specified conditions. The reaction results are shown in Table 3.

[0116]

Example 8

[0117] (1) Micron-nano dual-scale Y molecular sieves were prepared according to the following steps:

[0118] I: In a crystallization kettle, a certain amount of silicon source, aluminum source, and alkali source are weighed out and mixed with deionized water according to the molar ratio SiO2:Al2O3:Na2O:H2O = 7.9:1.0:2.9:200. The mixture is then sealed and crystallized at 100°C for 12 hours. After cooling, the mother liquor for the synthesis of micron-sized Y molecular sieves is obtained.

[0119] II: In the crystallization kettle, a certain amount of silicon source, aluminum source, and alkali source were weighed and mixed with deionized water according to the molar ratio SiO2:Al2O3:Na2O:H2O=24:1.0:25:500. The mixture was sealed and aged at 40℃ for 24 hours. After cooling, the mother liquor for the synthesis of nano Y molecular sieve was obtained.

[0120] III: Following a 1:1 molar ratio of SiO2 in the mother liquor for synthesizing micron-sized Y molecular sieves to SiO2 in the mother liquor for synthesizing nano-sized Y molecular sieves, the mother liquor for synthesizing nano-sized Y molecular sieves obtained after aging in step II was added to the mother liquor for synthesizing micron-sized Y molecular sieves obtained after crystallization in step I. After stirring evenly, the mixture was sealed and crystallized at 60°C for 24 hours. After crystallization, the solid was separated from the mother liquor by centrifugation. The solid was washed with deionized water and dried to obtain a micron-nano dual-scale Y molecular sieve.

[0121] The XRD pattern of the sample obtained in this example is as follows: Figure 5 As shown in the image.

[0122] In this example, the weight ratio of micron-Y molecular sieve to nano-Y molecular sieve in the micron-nano dual-scale Y molecular sieve is approximately 1:3.

[0123] (2) The composition containing micron-nano dual-scale Y molecular sieve was prepared according to [Example 1].

[0124] The obtained composition containing micron-nano dual-scale Y molecular sieve was crushed into particles of approximately 2 mm and placed into a quartz reaction tube with an inner diameter of 40 mm. Ethylene gas containing 50 ppm dimethyl sulfide was introduced into the reaction tube and allowed to react in the adsorption bed. The reaction temperature was 40 °C, the reaction system pressure was 1.0 atm, and the gas hourly space velocity was 6000 h⁻¹. 1 Ethylene feedstock was purified by adsorption under the specified conditions. The reaction results are shown in Table 3.

[0125]

Example 9

[0126] (1) The micron-nano dual-scale X molecular sieve was prepared according to [Example 1].

[0127] (2) The composition containing micron-nano dual-scale X molecular sieve was prepared according to [Example 1].

[0128] The obtained composition containing micron-nano dual-scale X-zeolite was crushed into particles of approximately 2 mm and placed into a quartz reaction tube with an inner diameter of 40 mm. Ethylene gas containing 100 ppm dimethyl sulfide was introduced into the reaction tube and allowed to react in the adsorption bed. The reaction temperature was 40 °C, the reaction system pressure was 1.0 atm, and the gas hourly space velocity was 6000 h⁻¹. 1 Ethylene feedstock was purified by adsorption under the specified conditions. The reaction results are shown in Table 3.

[0129] Comparative Example 1

[0130] (1) Micron-X molecular sieves are prepared according to the following steps:

[0131] I: In the crystallization kettle, a certain amount of silicon source, aluminum source, and alkali source are weighed out and mixed evenly with deionized water according to the molar ratio SiO2:Al2O3:Na2O:H2O=10.0:1.0:6.0:250, and then sealed. The mixture is then crystallized at 100℃ for 24 hours.

[0132] II: After crystallization, the solid is separated from the mother liquor by centrifugation. The solid is washed with deionized water and dried to obtain micron-sized X molecular sieve.

[0133] The XRD pattern of the sample obtained in Comparative Example 1 is as follows: Figure 1 As shown in a, the scanning electron microscope (SEM) image is as follows: Figure 3 As shown in the image.

[0134] (2) Preparation of compositions containing micron-sized X-ray molecular sieves:

[0135] Micron-X molecular sieve, pseudoboehmite powder, and copper nitrate salt were weighed separately to ensure that the dry basis ratio of Al2O3 corresponding to molecular sieve and pseudoboehmite and CuO corresponding to copper nitrate was 30:64:6. After mixing, the mixture was extruded into thin strips with a diameter of 1.8 mm. The extruded strips were dried at 80°C for 24 hours and calcined at 500°C for 5 hours to obtain a composition containing micron-X molecular sieve.

[0136] The obtained composition containing micron-sized X-ray molecular sieves was crushed into particles of approximately 2 mm and placed into a quartz reaction tube with an inner diameter of 40 mm. Ethylene gas containing 50 ppm dimethyl sulfide was introduced into the reaction tube and allowed to react in the adsorption bed. The reaction temperature was 40 °C, the reaction system pressure was 1.0 atm, and the gas hourly space velocity was 6000 h⁻¹. 1 Ethylene feedstock was purified by adsorption under the specified conditions. The reaction results are shown in Table 3.

[0137] Comparative Example 22

[0138] (1) Nano X molecular sieves were prepared according to the following steps:

[0139] I: In a crystallization reactor, a certain amount of silicon source, aluminum source, and alkali source are weighed out and mixed with deionized water according to the molar ratio SiO2:Al2O3:Na2O:H2O=24:1.0:25:500. The mixture is then sealed and aged at 40℃ for 24 hours. After cooling, mother liquor I is obtained.

[0140] II: In the crystallization kettle, a certain amount of silicon source, aluminum source, alkali source and deionized water are weighed according to the molar ratio of SiO2:Al2O3:Na2O:H2O=4.0:1.0:6.0:80, and mixed evenly to obtain mother liquor II;

[0141] III: According to the molar ratio of SiO2 in mother liquor I to SiO2 in mother liquor II of 1:1, add mother liquor I obtained after aging in step I to mother liquor II obtained in step II, stir evenly, seal, and continue crystallization at 60°C for 24 hours; after crystallization is completed, separate the solid from the mother liquor by centrifugation, wash the solid with deionized water, and dry to obtain nano X molecular sieve.

[0142] (2) Preparation of compositions containing nano-X molecular sieves:

[0143] Weigh the obtained nano-X molecular sieve, pseudoboehmite powder, and copper nitrate salt separately to ensure that the dry basis ratio of the molecular sieve, the Al2O3 corresponding to pseudoboehmite, and the CuO corresponding to copper nitrate is 30:64:6. After mixing, prepare thin strips with a diameter of 1.8 mm by extrusion molding. Dry the extruded strips at 80°C for 24 hours and calcine them at 500°C for 5 hours to obtain a composition containing nano-X molecular sieve.

[0144] The obtained composition containing nano-X molecular sieves was crushed into particles of approximately 2 mm and placed into a quartz reaction tube with an inner diameter of 40 mm. Ethylene gas containing 50 ppm dimethyl sulfide was introduced into the reaction tube and allowed to react in the adsorption bed. The reaction temperature was 40 °C, the reaction system pressure was 1.0 atm, and the gas hourly space velocity was 6000 h⁻¹. 1 Ethylene feedstock was purified by adsorption under the specified conditions. The reaction results are shown in Table 3.

[0145] Comparative Example 3

[0146] Micron / nano dual-scale hybrid X-molecule sieves were prepared according to the following steps:

[0147] (I) Micron-X molecular sieves were prepared according to [Comparative Example 1];

[0148] (II) Nano-X molecular sieves were prepared according to [Comparative Example 2];

[0149] (III) Weigh the micron-sized X molecular sieve and the nano-sized X molecular sieve prepared by the above method at a weight ratio of 1:3, and mix them by grinding to prepare a micron / nano dual-scale mixed X molecular sieve.

[0150] Preparation of compositions containing micron / nano dual-scale mixed X-zeolites:

[0151] Weigh the obtained micron / nano dual-scale X molecular sieve, pseudoboehmite powder, and copper nitrate salt separately to ensure that the dry basis ratio of the molecular sieve, the Al2O3 corresponding to pseudoboehmite, and the CuO corresponding to copper nitrate is 30:64:6. After mixing, prepare thin strips with a diameter of 1.8 mm by extrusion molding. Dry the extruded strips at 80°C for 24 hours and calcine them at 500°C for 5 hours to obtain a composition containing micron / nano dual-scale mixed X molecular sieve.

[0152] The above-obtained composition containing micron / nano dual-scale mixed X molecular sieves was broken into fine strips of approximately 2 mm and packed into a quartz reaction tube with an inner diameter of 40 mm. Ethylene gas containing 50 ppm dimethyl sulfide was introduced into the reaction tube and allowed to react in the adsorption bed. The reaction temperature was 40 °C, the reaction system pressure was 1.0 atm, and the gas hourly space velocity was 6000 h⁻¹. 1 Ethylene feedstock was purified by adsorption under the specified conditions. The reaction results are shown in Table 3.

[0153] Table 1. Composition of the molecular sieve compositions obtained in each example.

[0154]

[0155]

[0156] Table 2. Properties of the micron-nano dual-scale FAU molecular sieves obtained in each example.

[0157]

[0158]

[0159] Table 3 Evaluation results of the molecular sieve compositions obtained in each example

[0160]

[0161] The specific embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combining the various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A molecular sieve composition, characterized in that, The molecular sieve composition comprises, by weight, the following components: a) 10–80 parts of micron-nano dual-scale FAU molecular sieve; b) 10–80 parts adhesive; c) 0-10 parts of the modifier; The modifier is selected from at least one of Group IIB, Group VIB, and Group VIII metal oxides; the total pore volume of the micron-nano dual-scale FAU molecular sieve is 0.80–1.20 cm³. 3 / g.

2. The molecular sieve composition according to claim 1, characterized in that, The molecular sieve composition comprises, by weight, the following components: a) 20–80 parts of micron-nano dual-scale FAU molecular sieves; b) 20–80 parts adhesive; c) 1 to 10 parts of the modifier, preferably 2 to 8 parts.

3. The molecular sieve composition according to claim 1, characterized in that, The micron-nano dual-scale FAU molecular sieve has a crystal size of 10-200 nanometers, preferably 20-100 nanometers, for the nano-FAU molecular sieve and a crystal size of 1.0-10.0 micrometers, preferably 2.0-5.0 micrometers for the micron-FAU molecular sieve. And / or, in the micron-nano dual-scale FAU molecular sieve, the mass ratio of micron-FAU molecular sieve to nano-FAU molecular sieve is 1:3 to 3:1, preferably 1:3 to 2:

3.

4. The molecular sieve composition according to claim 1, characterized in that, The SiO2 / Al2O3 molar ratio of the micron-nano dual-scale FAU molecular sieve is 2.0 to 10.

0.

5. The molecular sieve composition according to claim 1, characterized in that, The micron-nano dual-scale FAU molecular sieve is selected from at least one of NaX, LiX, KX, NH4X, HX, MgX, CaX, NaY, LiY, KY, NH4Y, HY, MgY and CaY molecular sieves. And / or, the binder is selected from at least one of alumina, boehmite, kaolin, and montmorillonite; And / or, the modifier is selected from at least one of Cr2O3, MnO2, Fe2O3, Co2O3, Ni2O, CuO or ZnO.

6. A method for preparing the molecular sieve composition according to any one of claims 1-5, comprising the following steps: Micron-nano dual-scale FAU molecular sieves, binders, and optional modifiers are mixed, shaped, dried, and calcined to obtain the molecular sieve composition.

7. The preparation method according to claim 6, characterized in that, The preparation method of the micron-nano dual-scale FAU molecular sieve includes: (I) Water, silicon source, alkali source and aluminum source are mixed and crystallized I to obtain micron-sized FAU molecular sieve synthesis mother liquor; (II) Water, silicon source, alkali source and aluminum source are mixed and aged to obtain the mother liquor for the synthesis of nano-FAU molecular sieve; (III) Add the synthetic mother liquor of nano-FAU molecular sieve obtained in step (II) to the synthetic mother liquor of micron-FAU molecular sieve obtained in step (I), crystallize it in step II, and dry it to obtain micron-nano dual-scale FAU molecular sieve.

8. The preparation method according to claim 7, characterized in that, In step (I), the crystallization conditions include: crystallization temperature of 80-120°C and crystallization time of 2-60 hours; And / or, and / or, in step (II), the aging conditions include: an aging temperature of 20 to 60°C and an aging time of 2 to 60 hours; And / or, in step (III), the crystallization II conditions include: a crystallization II temperature of 40 to 80°C and a crystallization II time of 2 to 120 hours.

9. The preparation method according to claim 7, characterized in that, In step (I), the molar ratio of silicon source (SiO2), aluminum source (Al2O3), alkali source (M2O), and water is 1.0–12.0 SiO2:1.0 Al2O3:1.0–10.0 M2O:100.0–300.0 H2O; And / or, in step (II), the molar ratio of silicon source (SiO2), aluminum source (Al2O3), alkali source (M2O), and water is 1.0–25.0 SiO2:1.0 Al2O3:1.0–25.0 M2O:100.0–500.0 H2O; And / or, in step (III), the molar ratio of SiO2 in the mother liquor for the synthesis of micron-sized FAU molecular sieves to that in the mother liquor for the synthesis of nano-sized FAU molecular sieves is 10:1 to 1:

10.

10. The preparation method according to claim 7, characterized in that, In steps (I) and (II), the silicon source is independently selected from at least one of sodium silicate, water glass, silica sol, white carbon black, and tetraethyl orthosilicate; the aluminum source is independently selected from at least one of aluminum nitrate, aluminum sulfate, aluminum powder, aluminum sol, sodium aluminate, aluminum isopropoxide, and tert-butylaluminum; and the alkali source is independently selected from at least one of sodium hydroxide, potassium hydroxide, ammonium hydroxide, tetramethylammonium hydroxide, and tetraethylammonium hydroxide.

11. A method for removing sulfur-containing compounds from olefin feedstock, comprising reacting the olefin feedstock with a molecular sieve composition according to any one of claims 1-5 or a molecular sieve composition prepared by any one of claims 6-10 to obtain a purified olefin feedstock, wherein the sulfur-containing compounds in the olefin feedstock are selected from at least one of organothiols, thioethers, and thiophenes.

12. The method according to claim 11, characterized in that, The olefin feedstock is selected from at least one of ethylene, propylene, and butene; Preferably, the volume concentration of sulfur-containing compounds in the olefin feedstock is 10 to 1000 ppm, more preferably 50 to 200 ppm.

13. The method according to claim 11, characterized in that, The reaction conditions include: temperature of 10–60℃, pressure of 0–4.0 MPa, and ethylene feedstock volume hourly space velocity of 500–10000 h⁻¹. -1 .

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