CN113929111B - Synthesis method of high-crystallinity beta molecular sieve - Google Patents
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Abstract
The invention belongs to the technical field of molecular sieve synthesis, and relates to a method for synthesizing a high-crystallinity beta molecular sieve, which comprises the following steps: (1) The ZSM-5 molecular sieve surface is pretreated, and beta molecular sieve seed crystals are adsorbed to form a modified ZSM-5 molecular sieve; (2) A silicon source, an aluminum source, a template agent, sodium hydroxide and water form beta molecular sieve synthetic solution; (3) Uniformly mixing the modified ZSM-5 molecular sieve and beta molecular sieve synthetic solution to form a crystallization mixture; wherein the weight of the modified ZSM-5 molecular sieve based on the dry basis accounts for 0.1 to 10 percent of the weight of the dry basis of the crystallization mixture; and (4) crystallizing the crystallized mixture. The method can synthesize the beta molecular sieve with high crystallinity.
Description
Technical Field
The invention belongs to the technical field of molecular sieve synthesis, and relates to a beta molecular sieve synthesis method.
Background
Zeolite molecular sieve is a kind of microporous crystal material with skeleton structure, pore canal structure with specific size and shape, relatively large specific surface area and relatively strong adjustable acid property, and may be used widely in petroleum refining and processing, such as catalytic cracking, alkane isomerization, catalytic reforming, toluene disproportionation, etc.
Beta molecular sieves (or beta zeolite) were first synthesized in 1967 by the company Mo Bier in the united states using classical hydrothermal crystallization (USP 3308069). The molecular sieve has a unique three-dimensional pore structure, has very high hydrocracking and hydroisomerization catalytic activity, and can be used in petroleum refining and petrochemical processes such as hydrocracking, hydroisomerization, hydrofining, hydrodewaxing, diesel oil pour point depressing and the like after being modified or loaded with certain metal components. USP3308069 will contain Na 2 O、Al 2 O 3 、TEAOH、SiO 2 And water, crystallizing at 75-200 deg.C in high pressure kettle3-60 d. The method has the advantages of large template dosage, low crystallization speed and low molecular sieve crystallinity.
Disclosure of Invention
The invention aims to provide a novel beta molecular sieve synthesis method capable of improving the crystallinity of a beta molecular sieve.
A method for synthesizing a beta molecular sieve with high crystallinity comprises the following steps:
(1) The ZSM-5 molecular sieve surface is pretreated, and beta molecular sieve seed crystals are adsorbed to form a modified ZSM-5 molecular sieve;
(2) A silicon source, an aluminum source, a template agent, sodium hydroxide and water form beta molecular sieve synthetic solution;
(3) Uniformly mixing the modified ZSM-5 molecular sieve and beta molecular sieve synthetic solution to form a crystallization mixture; wherein the weight of the modified ZSM-5 molecular sieve on a dry basis is 0.1% to 10%, for example 1% to 9%, of the weight of the crystallization mixture on a dry basis;
(4) Crystallizing the crystallization mixture.
The synthesis method of the high-crystallinity beta molecular sieve according to the technical scheme, wherein the silicon-aluminum molar ratio of the ZSM-5 molecular sieve is SiO 2 /Al 2 O 3 Counting to be 20 to infinity.
The method for synthesizing a high crystallinity beta molecular sieve according to any of the above-described aspects, wherein the beta molecular sieve seed (beta molecular sieve) has a molar ratio of silicon to aluminum of SiO 2 /Al 2 O 3 The meter may be 20 to 200.
The method for synthesizing the high-crystallinity beta molecular sieve according to any one of the above technical schemes, wherein the surface pretreatment of the ZSM-5 molecular sieve is to treat the ZSM-5 with a surfactant, and in one embodiment, the method for surface pretreatment of the ZSM-5 molecular sieve comprises the following steps: adding ZSM-5 molecular sieve into surfactant solution with concentration of 0.05-30 wt%, preferably 0.1-15 wt%, for example 0.1-5 wt%, for at least 0.5 hr, for example 0.5-48 hr, filtering and drying to obtain the ZSM-5 molecular sieve with pretreated surface.
The method for synthesizing a high crystallinity beta molecular sieve according to any of the above technical schemes, wherein in one embodiment, the weight ratio of the surfactant solution to the ZSM-5 molecular sieve on a dry basis is 10-200:1.
The method for synthesizing the high-crystallinity beta molecular sieve according to any one of the above technical schemes, wherein in one embodiment, the surface pretreatment time of the ZSM-5 molecular sieve is 1 h-36 h, and the treatment temperature is 20-70 ℃.
The method for synthesizing a high crystallinity beta molecular sieve according to any of the above-mentioned embodiments, wherein the surfactant solution may further contain a salt, wherein the salt is a salt having a separation effect on the surfactant and having an electrolyte property, such as one or more of sodium chloride, potassium chloride, ammonium chloride, and ammonium nitrate; the concentration of salt in the surfactant solution is preferably 0.05 wt% to 10.0 wt%. The addition of the salt facilitates adsorption of the surfactant.
The method for synthesizing a high crystallinity beta molecular sieve according to any of the above technical schemes, wherein the surfactant is one or more of polymethyl methacrylate, polydiallyl dimethyl ammonium chloride, dipicolinic acid, ammonia water, ethylamine, n-butylamine, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetraethylammonium bromide, tetrapropylammonium bromide, tetrabutylammonium hydroxide.
The method for synthesizing a high crystallinity beta molecular sieve according to any of the above technical schemes, wherein the ZSM-5 molecular sieve is Na ZSM-5 and/or HZSM-5 molecular sieve.
The synthesis method of the high-crystallinity beta molecular sieve according to any of the above technical schemes, wherein the method for adsorbing the beta seed crystal is as follows: the ZSM-5 molecular sieve subjected to surface pretreatment is mixed with slurry containing the beta molecular sieve, stirred for more than 0.5 hours, such as 1 to 24 hours, at a temperature of 20 to 60 ℃, and then filtered and dried to obtain the modified ZSM-5 molecular sieve.
The method for synthesizing a high crystallinity beta molecular sieve according to the above-described aspect, wherein in the method for adsorbing beta seed crystals, the content of beta molecular sieve in the slurry containing beta molecular sieve is 0.1 wt% to 10 wt%, for example, 0.3 wt% to 8 wt% or 0.2 wt% to 1 wt%.
The method for synthesizing a high crystallinity beta molecular sieve according to any of the above technical schemes, wherein in the method for adsorbing beta seed crystals, the weight ratio of the slurry containing beta molecular sieve to the ZSM-5 molecular sieve on a dry basis is 10-50:1.
The synthesis method of the high-crystallinity beta molecular sieve according to any of the above technical schemes, wherein in the step (2), a silicon source, an aluminum source and a template agent are represented by R, and the molar ratio of water is: R/SiO 2 ＝0.05～10，H 2 O/SiO 2 ＝2～150：1，SiO 2 /Al 2 O 3 ＝10～800:1，Na 2 O/SiO 2 ＝0～2:1。
The method for synthesizing a high crystallinity beta molecular sieve according to any of the above technical schemes, wherein in step (2), the R/SiO 2 May be 0.05 to 3:1 or 0.2 to 2.2:1.
The process for synthesizing a high crystallinity beta molecular sieve according to any of the above aspects, wherein the H in step (2) 2 O/SiO 2 Can be 10-120:1.
The process for synthesizing a high crystallinity beta molecular sieve according to any of the above aspects, wherein the SiO in step (2) 2 /Al 2 O 3 May be 20-800:1.
The method for synthesizing a high crystallinity beta molecular sieve according to any of the above technical schemes, wherein the Na in step (2) 2 O/SiO 2 May be 0.01 to 1.7:1 or 0.05 to 1.3:1 or 0.1 to 1.1:1.
The method for synthesizing a high crystallinity beta molecular sieve according to any of the above technical solutions, wherein in step (2), the silicon source is one or more of silicone grease such as ethyl orthosilicate, water glass, coarse pore silica gel, silica sol, white carbon black or activated clay.
The method for synthesizing a high crystallinity beta molecular sieve according to any of the above technical schemes, wherein in the step (2), the aluminum source is one or more of aluminum sulfate, aluminum isopropoxide, aluminum nitrate, aluminum sol, sodium metaaluminate or gamma-alumina.
The method for synthesizing a high crystallinity beta molecular sieve according to any of the above technical schemes, wherein in the step (2), the template agent is one or more of tetraethylammonium fluoride, tetraethylammonium hydroxide, tetraethylammonium iodide, tetraethylammonium bromide, tetraethylammonium chloride, tetraethylammonium hydroxide, triethylamine, isopropylamine, di-n-propylamine, cetyltrimethylammonium bromide, isopropanol, polyvinyl alcohol, triethanolamine and sodium carboxymethyl cellulose.
According to any one of the above technical schemes, in the step (2), the silicon source, the aluminum source, the template agent and water are mixed, preferably deionized water, and stirred uniformly to form the beta molecular sieve synthetic solution.
The synthesis method of the high-crystallinity beta molecular sieve according to any of the technical schemes, wherein the crystallization in the step (4) is carried out at the temperature of 80-180 ℃ for 10-80 hours.
The synthesis method of the high-crystallinity beta molecular sieve according to any of the above technical schemes, wherein the crystallization mixture in the step (4) is crystallized for 20-70 h at 100-180 ℃; preferably, the crystallization temperature is 120-160 ℃, and the crystallization time is 32-60 h.
The method for synthesizing a high crystallinity beta molecular sieve according to any of the above technical schemes, wherein in the step (4), the step of recovering the beta molecular sieve may be further included after the crystallization is completed. The recovery typically comprises one or more steps of filtration, washing, drying, which are not particularly demanding compared to the prior art. The washing, in one embodiment, may be performed with water, such as deionized water, according to the beta molecular sieve: water=1:5-20 ratio, and can be washed one or more times until the pH value of the washed water is 8-9.
The synthesis method of the beta molecular sieve provided by the invention has at least one of the following beneficial effects, and preferably has a plurality of beneficial effects.
(1) The crystallinity of the synthesized beta molecular sieve is improved, and the beta molecular sieve with higher crystallinity can be obtained;
(2) Beta molecular sieve with higher crystallinity can be synthesized in shorter time;
(3) The dosage of the guiding agent can be reduced, and the beta molecular sieve with higher crystallinity can be rapidly synthesized under the condition of reducing the dosage of the guiding agent;
(4) The ZSM-5 molecular sieve is converted into raw materials for synthesizing the beta molecular sieve in the synthesis process, and the XRD spectrum of the synthesized product has no ZSM-5 molecular sieve characteristic peak;
(5) The silicon-aluminum ratio of the synthesized beta molecular sieve can be improved;
(6) According to the molecular sieve synthesis method provided by the invention, the ZSM-5 molecular sieve has the same secondary structural unit (mor (t-tes)) with beta, and is converted into the beta molecular sieve through dissolution and recrystallization under the condition of a small amount of organic structure directing agent, the crystallization speed of the beta molecular sieve is accelerated by the synergistic guiding action of the organic structure directing agent and the heterogeneous seed crystal, the crystallinity of the beta molecular sieve is improved, and the synthesis cost of the beta molecular sieve can be reduced.
Drawings
Figure 1 is an XRD pattern of the beta molecular sieve synthesized in example 1 of the present invention.
Detailed Description
The following examples are provided to further illustrate the invention but are not intended to limit it.
In the examples and comparative examples, the crystallinity was analyzed by XRD, see standard ASTM D5758-2001 (2011) e1.
ZSM-5 molecular sieve (also known as ZSM-5 seed): silicon to aluminum ratio (in terms of SiO) 2 /Al 2 O 3 Meter) 25, type H, relative crystallinity 91.0%, from ziluta corporation, chinese petrochemical catalyst, inc.
Comparative example 1
1.0g of sodium aluminate is dissolved in 18g of deionized water, 0.6g of NaOH particles are added, 10g of coarse pore silica gel and 18g of tetraethylammonium hydroxide solution (mass fraction of tetraethylammonium hydroxide is 25%) are sequentially added, after being fully and uniformly stirred, the mixture is transferred into a polytetrafluoroethylene lining reaction kettle for crystallization, the mixture is crystallized for 40 hours at 130 ℃, and after the crystallization is finished, the mixture is subjected to suction filtration, washing and drying. The beta molecular sieve was obtained and designated DB1.
Example 1
At 25 ℃, the ZSM-5 molecular sieve was added to an aqueous solution of methyl methacrylate and sodium chloride (0.2% by mass of methyl methacrylate and 0.2% by mass of sodium chloride) and the weight ratio of the ZSM-5 molecular sieve (on a dry basis) to the aqueous solution of methyl methacrylate and sodium chloride was 0.5, stirred for 2 hours, filtered, and then dried under an air atmosphere at 40 ℃. Then put into the beta molecular sieve seed crystal suspension (beta molecular sieve content in the beta molecular sieve seed crystal suspension is 0.5 wt%, beta molecular sieve seed crystal is beta molecular sieve prepared in comparative example 1), the weight ratio of the beta molecular sieve seed crystal suspension to ZSM-5 molecular sieve based on dry basis is 10, stirred for 1 hour at 40 ℃, filtered, and dried in air atmosphere at 90 ℃ to obtain ZSM-5 molecular sieve (also called modified ZSM-5 molecular sieve) adhered with beta molecular sieve seed crystal. 1.0g of sodium aluminate is dissolved in 18g of deionized water, 0.6g of NaOH particles are added, 10g of coarse pore silica gel (Shandong Yiming Yimao Koku Co., ltd.) and 18g of tetraethylammonium hydroxide solution (tetraethylammonium hydroxide mass fraction 25%) are sequentially added, after the mixture is fully and uniformly stirred, beta seed crystal-adhered ZSM-5 molecular sieve is added to obtain beta molecular sieve crystallization mixture (the weight proportion of beta seed crystal-adhered ZSM-5 molecular sieve in dry basis is 1.5 percent) which is transferred into a polytetrafluoroethylene lining reaction kettle for crystallization, crystallization is carried out at 130 ℃ for 40 hours, and suction filtration, washing and drying are carried out after crystallization is finished. The beta molecular sieve was obtained and designated B1.
Comparative example 2
1.2g of aluminum isopropoxide was dissolved in 23g of deionized water, 2.4g of NaOH particles were added, followed by 50g of silica sol (SiO 2 Content 25.0 wt%, alkaline silica sol, na 2 O content 0.1%) and 35g tetraethylammonium hydroxide solution (tetraethylammonium hydroxide mass fraction 25%), after being fully and evenly stirred, the mixture is transferred into a polytetrafluoroethylene lining reaction kettle for crystallization, and the mixture is crystallized for 36 hours at 150 ℃. And after crystallization, carrying out suction filtration, washing and drying to obtain the beta molecular sieve DB2.
Example 2
ZSM-5 molecular sieve was added to a salt solution of methyl methacrylate (the solution having a methyl methacrylate content of 0.2% by weight and a sodium chloride content of 0.2% by weight) at 25℃for 2 hours, filtered and dried under an air atmosphere at 40 ℃. Then put into beta fractionIn the molecular sieve seed crystal suspension (the content of the beta molecular sieve in the molecular sieve seed crystal suspension is 4.6 weight percent, wherein the beta molecular sieve serving as the seed crystal is the beta molecular sieve prepared by the method of the comparative example 2), the weight ratio of the molecular sieve seed crystal suspension to the ZSM-5 molecular sieve based on a dry basis is 20, the molecular sieve seed crystal suspension is stirred for 1 hour at the temperature of 40 ℃, is treated, filtered and dried in an air atmosphere at the temperature of 90 ℃ to obtain the ZSM-5 molecular sieve adhered with the beta seed crystal. 1.2g of aluminum isopropoxide was dissolved in 23g of deionized water, 2.4g of NaOH particles were added, followed by 50g of silica sol (SiO 2 The content of the alkaline silica sol is 25.0 wt%, the content of sodium oxide is 0.1 wt%) and 35g of tetraethylammonium hydroxide solution (tetraethylammonium hydroxide mass fraction is 25 wt%) are fully and uniformly stirred to obtain a synthetic liquid, then the beta seed crystal-adhered ZSM-5 molecular sieve is added to obtain a beta molecular sieve crystallization mixture, and the weight proportion of the beta seed crystal-adhered ZSM-5 molecular sieve in the beta molecular sieve crystallization mixture in dry basis is 3.5%. And transferring the beta molecular sieve crystallization mixture into a polytetrafluoroethylene lining reaction kettle, crystallizing for 36 hours at 150 ℃, and carrying out suction filtration, washing and drying after crystallization. To obtain the beta molecular sieve B2.
Comparative example 3
Dissolving 0.6g of aluminum nitrate into 69g of deionized water, adding 2.4g of NaOH particles, sequentially adding 30g of tetraethoxysilane and 28g of tetraethylammonium hydroxide solution (mass concentration is 25%), fully and uniformly stirring, transferring into a polytetrafluoroethylene lining reaction kettle for crystallization, crystallizing at 100 ℃ for 72h, and carrying out suction filtration, washing and drying after the crystallization is finished to obtain the beta molecular sieve DB3.
Example 3
At normal temperature, adding ZSM-5 molecular sieve into a salt solution of methyl methacrylate (the salt solution contains 0.2 weight percent of methyl methacrylate and 0.2 weight percent of sodium chloride) for 2 hours, filtering and drying under the air atmosphere at 40 ℃, wherein the weight ratio of the dry basis of the ZSM-5 molecular sieve to the salt solution of the methyl methacrylate is 1:14; then, the mixture was put into a beta molecular sieve seed crystal suspension (the beta molecular sieve content in the beta molecular sieve seed crystal suspension is 7.9 wt%, which is beta molecular sieve DB3 obtained in comparative example 3), and the treatment temperature was 40 ℃ for 1 hour, and the mixture was filtered and dried in an air atmosphere at 90 ℃ to obtain a beta seed crystal-adhered ZSM-5 molecular sieve. Dissolving 0.6g of aluminum nitrate into 69g of deionized water, adding 2.4g of NaOH particles, sequentially adding 30g of tetraethoxysilane and 28g of tetraethylammonium hydroxide solution (the mass fraction of tetraethylammonium hydroxide is 25%), fully and uniformly stirring, then adding beta-crystal seed adhered ZSM-5 molecular sieve to obtain beta-molecular sieve crystallization mixture (the weight proportion of beta-crystal seed adhered ZSM-5 molecular sieve on a dry basis is 8.4 percent of beta-molecular sieve crystallization mixture on a dry basis), transferring into a polytetrafluoroethylene lining reaction kettle for crystallization, crystallizing at 100 ℃ for 72 hours, and carrying out suction filtration, washing and drying after the crystallization is finished. To obtain the beta molecular sieve B3.
As shown in figure 1, the XRD spectrum of the beta molecular sieve synthesized by the embodiment of the invention has characteristic peaks of the beta molecular sieve and does not have characteristic peaks of a ZSM-5 molecular sieve.
Comparative example 4
Beta molecular sieves were synthesized following the procedure of example 1 except that no beta seed crystals were added.
Dissolving 1.0g of sodium aluminate in 18g of deionized water, adding 0.6g of NaOH particles, sequentially adding 10g of coarse pore silica gel and 18g of tetraethylammonium hydroxide solution (mass fraction of tetraethylammonium hydroxide is 25%), fully and uniformly stirring, adding ZSM-5 molecular sieve to obtain beta molecular sieve crystallization mixture (the weight proportion of ZSM-5 molecular sieve in the beta molecular sieve crystallization mixture based on dry basis is 1.5%), transferring into a polytetrafluoroethylene lining reaction kettle for crystallization, crystallizing at 130 ℃ for 40h, and carrying out suction filtration, washing and drying after crystallization.
Comparative example 5
Beta molecular sieves were synthesized following the procedure of example 1 except that beta seed crystals were added and no ZSM-5 was added. Wherein the ratio of beta seed crystals to dry mixture is 2 wt.%.
Dissolving 1.0g of sodium aluminate in 18g of deionized water, adding 0.6g of NaOH particles, sequentially adding 10g of coarse pore silica gel and 18g of tetraethylammonium hydroxide solution (the mass fraction of tetraethylammonium hydroxide is 25%), fully and uniformly stirring, adding a beta molecular sieve (the beta molecular sieve DB1 obtained in comparative example 1) as a seed crystal to obtain a beta molecular sieve crystallization mixture (the weight proportion of the beta molecular sieve seed crystal to the beta molecular sieve crystallization mixture calculated on a dry basis is 2.0 percent), transferring the mixture into a polytetrafluoroethylene-lined reaction kettle for crystallization, crystallizing at 130 ℃ for 40 hours, and carrying out suction filtration, washing and drying after the crystallization is finished.
Comparative example 6
According to the method of example 1, ZSM-5 molecular sieve is not adhered with beta seed crystal, adding the mixture of ZSM-5 and beta, wherein the proportion of ZSM-5 and beta is 10:1, the mixture of ZSM-5 and beta molecular sieve accounts for 1.5% of the weight of beta molecular sieve crystallization mixture based on dry basis, transferring into a polytetrafluoroethylene lining reaction kettle for crystallization, crystallizing at 130 ℃ for 40 hours, and after crystallization, filtering, washing and drying.
The proportions and product properties of the preparations of examples 1 to 3 and comparative examples 1 to 6 above are shown in Table 1.
TABLE 1
Wherein R represents a templating agent
As can be seen from Table 1, the method provided by the invention can improve the silicon-aluminum ratio of the synthesized beta molecular sieve, improve the crystallinity of the product, synthesize the beta molecular sieve with higher crystallinity in a shorter time, and obtain the molecular sieve with higher crystallinity under the condition of using a lower template agent.
Claims (19)
1. A method for synthesizing a beta molecular sieve with high crystallinity comprises the following steps:
(1) The ZSM-5 molecular sieve surface is pretreated, and beta molecular sieve seed crystals are adsorbed to form a modified ZSM-5 molecular sieve;
the ZSM-5 molecular sieve surface pretreatment comprises the following steps: adding the ZSM-5 molecular sieve into a surfactant solution with the weight percentage concentration of 0.05% -30% to treat for at least 0.5 hours, filtering and drying to obtain a ZSM-5 molecular sieve subjected to surface pretreatment; the surfactant is methyl methacrylate or at least one selected from polymethyl methacrylate, polydiallyl dimethyl ammonium chloride, pyridine dicarboxylic acid, ammonia water, ethylamine, n-butylamine, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetraethylammonium bromide, tetrapropylammonium bromide and tetrabutylammonium hydroxide, the surfactant solution contains salt with separation effect and electrolyte property on the surfactant, the concentration of the salt in the surfactant solution is 0.05-10 wt%, and the salt is one or more of sodium chloride, potassium chloride, ammonium chloride and ammonium nitrate;
the method for adsorbing the beta seed crystal comprises the following steps: mixing the ZSM-5 molecular sieve subjected to surface pretreatment with slurry containing the beta molecular sieve, wherein the content of the beta molecular sieve in the slurry containing the beta molecular sieve is 0.1-10 wt%, stirring the slurry for more than 0.5 hour at 20-60 ℃, filtering the slurry, and drying the slurry to obtain the modified ZSM-5 molecular sieve;
(2) A silicon source, an aluminum source, a template agent, sodium hydroxide and water form beta molecular sieve synthetic solution;
(3) Uniformly mixing the modified ZSM-5 molecular sieve and beta molecular sieve synthetic solution to form a crystallization mixture; wherein the weight of the modified ZSM-5 molecular sieve based on dry basis accounts for 0.1% -10% of the weight of the dry basis of the crystallization mixture;
(4) Crystallizing the crystallization mixture.
2. The process according to claim 1, wherein the ZSM-5 molecular sieve has a molar ratio of silica to alumina of SiO 2 /Al 2 O 3 Counting to be 20 to infinity.
3. The process of claim 1 wherein the beta molecular sieve seeds have a molar ratio of silicon to aluminum of SiO 2 /Al 2 O 3 The weight of the material is 20 to 200.
4. The method of claim 1, wherein the ZSM-5 molecular sieve surface pretreatment comprises: adding the ZSM-5 molecular sieve into a surfactant solution with the weight percentage concentration of 0.1-5 to treat 0.5-48 h, filtering and drying to obtain the ZSM-5 molecular sieve subjected to surface pretreatment.
5. The process according to claim 1, wherein the weight ratio of the surfactant solution to ZSM-5 molecular sieve on a dry basis is 10 to 200:1.
6. The method according to claim 1, wherein the surface pretreatment of the ZSM-5 molecular sieve is carried out at a treatment temperature of 20-70 ℃ for a treatment time of 1-36 hours.
7. The method of claim 1 wherein the surfactant is methyl methacrylate.
8. The process according to claim 1, wherein the ZSM-5 molecular sieve is a NaZSM-5 and/or HZSM-5 molecular sieve.
9. The method according to claim 1 or 4, wherein the method of adsorbing the beta seed is as follows: the ZSM-5 molecular sieve subjected to surface pretreatment is mixed with slurry containing beta molecular sieve, and stirred for 1-24 h at 20-60 ℃.
10. The method of claim 9, wherein the beta molecular sieve content in the beta molecular sieve-containing slurry is 0.3 wt% to 8 wt%.
11. The process of claim 9 wherein the weight ratio of the slurry containing the beta molecular sieve to the ZSM-5 molecular sieve on a dry basis is 10 to 50:1.
12. The method according to claim 1, wherein in the step (2), the silicon source, the aluminum source and the template agent are represented by R, and the molar ratio of water is: R/SiO 2 =0.05 ~ 10，H 2 O/SiO 2 = 2 ~ 150：1，SiO 2 /Al 2 O 3 = 10 ~ 800:1，Na 2 O/SiO 2 = 0 ~ 2:1。
13. The method of claim 12, wherein said R/SiO 2 =0.05 to 3:1, H 2 O/SiO 2 =10 to 120:1, the SiO 2 /Al 2 O 3 =20 to 800:1, na 2 O/SiO 2 = 0.01~1.7:1。
14. The method of claim 1, wherein in step (2), the silicon source is one or more of silicone grease, water glass, coarse pore silica gel, silica sol, white carbon black, or activated clay; the aluminum source is one or more of aluminum sulfate, aluminum isopropoxide, aluminum nitrate, aluminum sol, sodium metaaluminate or gamma-aluminum oxide; the template agent is one or more of tetraethylammonium fluoride, tetraethylammonium hydroxide, tetraethylammonium iodide, tetraethylammonium bromide, tetraethylammonium chloride, tetraethylammonium hydroxide, triethylamine, isopropylamine, di-n-propylamine, cetyl trimethyl ammonium bromide, isopropanol, polyvinyl alcohol, triethanolamine and sodium carboxymethyl cellulose.
15. The method according to claim 1, wherein the crystallization in the step (4) is performed at a temperature of 80 to 180 ℃ for a crystallization time of 10 to 80h.
16. The method according to claim 1, wherein the crystallization mixture in step (4) is crystallized at 100 to 180 ℃ for 20 to 70 h.
17. The process according to claim 1, wherein the weight of the modified ZSM-5 molecular sieve on a dry basis is 1% to 9% of the weight of the crystallization mixture on a dry basis.
18. The method according to claim 16, wherein in the step (4), the crystallization temperature is 120 to 160 ℃ and the crystallization time is 32 to 60h.
19. The method of claim 14 wherein said silicone grease is ethyl orthosilicate.
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| CN1647856A (en) * | 2004-01-19 | 2005-08-03 | 中国石油化工股份有限公司 | Method for preparing ZSM-5 and beta zeolite mixed crystal material |
| CN101885493A (en) * | 2009-05-13 | 2010-11-17 | 中国石油化工股份有限公司 | Synthesis method of ZSM-5/beta nuclear shell-shaped molecular sieve |
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Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1647856A (en) * | 2004-01-19 | 2005-08-03 | 中国石油化工股份有限公司 | Method for preparing ZSM-5 and beta zeolite mixed crystal material |
| CN101885493A (en) * | 2009-05-13 | 2010-11-17 | 中国石油化工股份有限公司 | Synthesis method of ZSM-5/beta nuclear shell-shaped molecular sieve |
Non-Patent Citations (2)
| Title |
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| 核壳型复合分子筛 ZSM-5/Nano-β的合成与表征;童伟益 等;《高等学校化学学报》;20090531;第959-964页 * |
| 毛丽秋等 主编.β沸石的水热合成、组成测定及其结构表征.《化学研究与设计性实验》.湖南师范大学出版社,2008,第53页. * |
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