Organotemplate-free solid-state synthetic method for zeolite molecular sieves
10160656 · 2018-12-25
Assignee
Inventors
- Stefan MAURER (Shanghai Pudong, CN)
- Ulrich MÜLLER (Neustadt, DE)
- Feng-Shou XIAO (Changchun, CN)
- Xiangju Meng (Hangzhou Zejiang Province, CN)
- Qinming Wu (Hangzhou, CN)
Cpc classification
C01B39/02
CHEMISTRY; METALLURGY
B01J35/30
PERFORMING OPERATIONS; TRANSPORTING
B01J29/08
PERFORMING OPERATIONS; TRANSPORTING
C01B39/46
CHEMISTRY; METALLURGY
B01J37/009
PERFORMING OPERATIONS; TRANSPORTING
B01J29/70
PERFORMING OPERATIONS; TRANSPORTING
International classification
C01B39/46
CHEMISTRY; METALLURGY
B01J29/40
PERFORMING OPERATIONS; TRANSPORTING
B01J37/00
PERFORMING OPERATIONS; TRANSPORTING
B01J35/00
PERFORMING OPERATIONS; TRANSPORTING
B01J29/70
PERFORMING OPERATIONS; TRANSPORTING
B01J29/08
PERFORMING OPERATIONS; TRANSPORTING
C01B39/02
CHEMISTRY; METALLURGY
Abstract
Described is a preparation method for zeolite molecular sieves by means of solid-state reactions without the usage of organic templates. The method comprises the following steps: grinding and mixing the solid raw materials comprising the silicon source, the aluminum source and the alkali source, transferring the obtained mixture into an autoclave, conducting the crystallization for a period of 5 hours-20 days at a temperature of 50-200 C. After filtering and drying the crystallized products, molecular sieves in a powder form can be obtained. The method provides different molecular sieves, including ZSM-5 zeolite, Beta zeolite, FAU zeolite, MOR zeolite, LTA zeolite, and GIS zeolite, with a high crystallinity and an adjustable Si/Al ratio within a certain range. The obtained products exhibit a high crystallinity and a high purity, and the method does not require the use of organic templates and solvents, which avoids unnecessary consumptions during the production, simplifies the synthetic process, and also increases the yield from the autoclave reactor.
Claims
1. An organotemplate-free solid-state method for the synthesis of zeolite molecular sieves, the method comprising: grinding and mixing the weighed solid raw materials comprising the silicon source, the aluminum source and the alkali source; transferring the mixture into an autoclave; crystallizing the mixture at temperatures of between 50-200 C. for a time period of from 5 hours to 20 days; and filtering and drying the product for obtaining powders of molecular sieves; wherein each raw material is added within a molar ratio range of SiO.sub.2:0.25 Al.sub.2O.sub.3:0.39 Na.sub.2O:(2-3) H.sub.2O.
2. The method of claim 1, wherein the aluminum source is selected from aluminum sulfate or sodium aluminate; the silicon source is selected from sodium silicate, solid silica gel, white carbon black or amorphous silica powder; and the alkali source is selected from sodium hydroxide or sodium silicate.
3. An organotemplate-free solid-state method for the synthesis of zeolite molecular sieves, the method comprising: grinding and mixing the weighed solid raw materials comprising the silicon source, the aluminum source and the alkali source; transferring the mixture into an autoclave; crystallizing the mixture at temperatures of between 50-200 C. for a time period of from 5 hours to 20 days; and filtering and drying the product for obtaining powders of molecular sieves; wherein each raw material is added within a molar ratio range of SiO.sub.2:0.05 Al.sub.2O.sub.3:(0.1-0.16) Na.sub.2O:(2-3) H.sub.2O.
4. The method of claim 3, wherein the aluminum source is selected from aluminum sulfate or sodium aluminate; the silicon source is selected from sodium silicate, solid silica gel, white carbon black or amorphous silica powder; and the alkali source is selected from sodium hydroxide or sodium silicate.
5. An organotemplate-free solid-state method for the synthesis of zeolite molecular sieves, the method comprising: grinding and mixing the weighed solid raw materials comprising the silicon source, the aluminum source and the alkali source; transferring the mixture into an autoclave; crystallizing the mixture at temperatures of between 50-200 C. for a time period of from 5 hours to 20 days; and filtering and drying the product for obtaining powders of molecular sieves; wherein each raw material is added within a molar ratio range of SiO.sub.2:0.1 Al.sub.2O.sub.3:0.39 Na.sub.2O:(2-3) H.sub.2O.
6. The method of claim 5, wherein the aluminum source is selected from aluminum sulfate or sodium aluminate; the silicon source is selected from sodium silicate, solid silica gel, white carbon black or amorphous silica powder; and the alkali source is selected from sodium hydroxide or sodium silicate.
7. An organotemplate-free solid-state method for the synthesis of zeolite molecular sieves, the method comprising: grinding and mixing the weighed solid raw materials comprising the silicon source, the aluminum source and the alkali source: transferring the mixture into an autoclave; crystallizing the mixture at temperatures of between 50-200 C. for a time period of from 5 hours to 20 days; and filtering and drying the product for obtaining powders of molecular sieves; wherein each raw material is added within a molar ratio range of SiO.sub.2,:(0.056-0.083) Al.sub.2O.sub.3:(0.14-0.2) Na.sub.2O:(2-3) H.sub.2O: and wherein molecular sieve seed crystals are added and grinded together with the solid raw materials before crystallization, and wherein the mass ratio of the molecular sieve seed crystals to the raw silicon source is in a range of 1-10%.
8. The method of claim 7, wherein the aluminum source is selected from aluminum sulfate or sodium aluminate; the silicon source is selected from sodium silicate, solid silica gel, white carbon black or amorphous silica powder; and the alkali source is selected from sodium hydroxide or sodium silicate.
9. The method of claim 7, wherein each raw material is added within a molar ratio range of SiO.sub.2:(0.056-0.083) Al.sub.2O.sub.3:(0.14-0.2) Na.sub.2O:(2-3) H.sub.2O.
Description
BRIEF DESCRIPTION OF THE FIGURES
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DETAILED DESCRIPTION
(26) Provided is an organotemplate-free solid-state synthetic method overcomes the disadvantages of the molecular sieve synthesis known in the prior art and provides for zeolites including ZSM-5, Beta, FAU, MOR, LTA, and GIS molecular sieves.
(27) The organotemplate-free solid-state synthetic method for molecular sieves provided by the present invention comprises the following steps:
(28) Grinding and mixing the weighed solid raw materials comprising the silicon source, the aluminum source and the alkali source, then transferring the solid mixture into an autoclave and conducting crystallization for a time period from 5 hours to 20 days at temperatures of 50-200 C., and after a suction filtration and subsequent drying of the products, powders of molecular sieves can be obtained. In one or more embodiments, each raw material shall be added within a molar ratio range of SiO.sub.2:(0.016-0.5) Al.sub.2O.sub.3:(0.1-0.7) Na.sub.2O:(1.5-3) H.sub.2O.
(29) According to one or more embodiments of the present invention, each raw material shall be added within a molar ratio range of SiO.sub.2:0.25 Al.sub.2O.sub.3:0.39 Na.sub.2O:(2-3) H.sub.2O.
(30) According to one or more specific embodiments of the present invention, each raw material shall be added within a molar ratio range of SiO.sub.2:0.05 Al.sub.2O.sub.3:(0.1-0.16) Na.sub.2O:(2-3) H.sub.2O.
(31) According to other specific embodiments of the present invention, each raw material shall be added within a molar ratio range of SiO.sub.2:0.1 Al.sub.2O.sub.3:0.39 Na.sub.2O:(2-3) H.sub.2O.
(32) According to further specific embodiments of the present invention, each raw material shall be added within a molar ratio range of SiO.sub.2:0.5 Al.sub.2O.sub.3:0.7 Na.sub.2O:(3-4) H.sub.2O.
(33) According to one or more embodiments of the present invention, molecular sieve seed crystals are mixed and grinded together with the solid raw materials before crystallization. The mass ratio of said molecular sieve seed crystals to the silicon source is within a range of 1-10%.
(34) According to one or more embodiments, when molecular sieve seed crystals are added during the synthesis, each raw material shall be added within a molar ratio range of SiO.sub.2:(0.016-0.05) Al.sub.2O.sub.3:(0.14-0.25) Na.sub.2O:(1.5-3) H.sub.2O.
(35) According to one or more specific embodiments, when molecular sieve seed crystals are added during the synthesis, each raw material shall be added within a molar ratio range of SiO.sub.2:(0.056-0.083) Al.sub.2O.sub.3:(0.14-0.2) Na.sub.2O:(2-3) H.sub.2O.
(36) According to one or more embodiments, the aluminum source is aluminum sulfate or sodium aluminate; the silicon source is hydrated sodium silicate (Na.sub.2SiO.sub.4.9H.sub.2O), solid silica gel, white carbon black or amorphous silica powder; and the alkali source is sodium hydroxide or hydrated sodium silicate.
(37) The present invention has the following beneficial technical effects:
(38) Based on the solution of the present invention, ZSM-5 zeolite, Beta zeolite, FAU zeolite, MOR zeolite, LTA zeolite, and GIS zeolite with a high crystallinity and an adjustable Si/Al ratio within a certain range can be obtained.
(39) Compared to the prior art, the zeolite products obtained by the present invention have a high crystallinity and a high phase purity, and the whole production process is free of organic template agents and solvents, thus avoiding unnecessary consumption during the production process. Moreover, the synthetic method of the present invention simplifies the production of zeolites, and improves the yield of the zeolitic products obtained from the autoclave reactor. Therefore, this green synthetic route will significantly reduce the production costs, which may find potential application in the production of zeolites in the chemical industry.
(40) The invention is now described with reference to the following examples. Before describing several exemplary embodiments of the invention, it is to be understood that the invention is not limited to the details of construction or process steps set forth in the following description. The invention is capable of other embodiments and of being practiced or being carried out in various ways.
EXAMPLES
(41) X-ray powder diffraction (XRD) patterns were measured with a Rigaku Ultimate VI X-ray diffractometer (40 kV, 40 mA) using Cu.sub.K (=1.5406 ) radiation. The N.sub.2 sorption isotherms at the temperature of liquid nitrogen were measured using Micromeritics ASAP 2020M and Tristar system. The sample composition was determined by inductively coupled plasma (ICP) with a Perkin-Elmer 3300DV emission spectrometer. Scanning electron microscopy (SEM) experiments were performed on Hitachi SU-1510 electron microscopes. .sup.29Si MAS NMR spectra were recorded on a Varian Infinity Plus 400 spectrometer.
Example 1
Synthesis of Low Si/Al Ratio ZSM-5 Zeolite by the Organotemplate-free Solid-state Method
(42) 2 g of Na.sub.2SiO.sub.3.9H.sub.2O, 0.92 g of Al.sub.2(SO.sub.4).sub.3.18H.sub.2O, 1.3 g of solid silica gel and 0.17 g of ZSM-5 seed crystals (the amount of seed crystals is calculated with respect to the amount of raw silicon source) were poured into a mortar and mixed by grinding for 10 minutes. The mixture was then transferred into a polytetrafluorethylene lined stainless steel autoclave and the crystallization was conducted at 180 C. for 15 hours until the crystallization was complete. The product was filtered by suction filtration and followed by a drying step to obtain the final product in a powder form. The composition of the synthetic mixture is as follows:
(43) SiO.sub.2:0.05 Al.sub.2O.sub.3:0.25 Na.sub.2O:3 H.sub.2O. The mass ratio of seed crystals to the raw silicon source is 10%.
(44) It is determined by the X-ray diffraction analysis that the obtained product is a ZSM-5 zeolite.
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Example 2
Utilization of the ZSM-5 Zeolite Synthesized by the Organotemplate-free Solid-state Method of Example 1 as Seed Crystals
(46) 2 g of Na.sub.2SiO.sub.3.9H.sub.2O, 0.92 g of Al.sub.2(SO.sub.4).sub.3.18H.sub.2O, 1.3 g of solid silica gel and 0.17 g of ZSM-5 seed crystals obtained from Example 1 were poured into a mortar and mixed by grinding for 10 minutes. The mixture than was transferred into a polytetrafluorethylene lined stainless steel autoclave and crystallization was conducted at 180 C. for 15 hours until the crystallization was complete. The product was filtered off by suction filtration followed by a drying step to obtain the final product in a powder form. The composition of the synthetic mixture is as follows:
(47) SiO.sub.2:0.05 Al.sub.2O.sub.3:0.25 Na.sub.2O:3 H.sub.2O. The mass ratio of seed crystals to the raw silicon source is 10%.
(48) It is determined by the X-ray diffraction analysis that the obtained product is a ZSM-5 zeolite
Example 3
Synthesis of High Si/Al Ratio ZSM-5 Zeolite by the Organotemplate-free Solid-state Method
(49) 1.1 g of Na.sub.2SiO.sub.3.9H.sub.2O, 0.3 g of Al.sub.2(SO.sub.4).sub.3.18H.sub.2O, 1.4 g of solid silica gel and 0.17 g of ZSM-5 seed crystals (the amount of seed crystals is calculated with respect to the amount of raw silicon source) were poured into a mortar and mixed by grinding for 10 minutes. The mixture was then transferred into a polytetrafluorethylene lined stainless steel autoclave and crystallization was conducted at 180 C. for 15 hours until the crystallization was complete. The product was filtered by suction filtration and followed by a drying step to obtain the final product in a powder form. The composition of the synthetic mixture is as follows:
(50) SiO.sub.2:0.016 Al.sub.2O.sub.3:0.14 Na.sub.2O:1.5 H.sub.2O. The mass ratio of seed crystals to the raw silicon source is 10%. It is determined by the X-ray diffraction analysis that the obtained product is a ZSM-5 zeolite.
Example 4
Synthesis of ZSM-5 Zeolite by the Organotemplate-free Solid-state Method
(51) 1.5 g of Na.sub.2SiO.sub.3.9H.sub.2O, 0.65 g of Al.sub.2(SO.sub.4).sub.3.18H.sub.2O, 1.35 g of solid silica gel and 0.17 g of ZSM-5 seed crystals (the amount of seed crystals is calculated with respect to the amount of raw silicon source) were poured into a mortar and mixed by grinding for 10 minutes. The mixture was then transferred into a polytetrafluorethylene lined stainless steel autoclave and crystallization was conducted at 180 C. for 15 hours until the crystallization was completed. The product was filtered by suction filtration and followed by a drying step to obtain the final product in a powder form. The composition of the synthetic mixture is as follows:
(52) SiO.sub.2:0.034 Al.sub.2O.sub.3:0.19 Na.sub.2O:2.3 H.sub.2O. The mass ratio of seed crystals to the raw silicon source is 10%. It is determined by the X-ray diffraction analysis that the obtained product is a ZSM-5 zeolite.
Example 5
Synthesis of ZSM-5 Zeolite at a High Temperature in a Short Time
(53) 1.5 g of Na.sub.2SiO.sub.3.9H.sub.2O, 0.65 g of Al.sub.2(SO.sub.4).sub.3.18H.sub.2O, 1.35 g of solid silica gel and 0.17 g of ZSM-5 seed crystals (the amount of seed crystals is calculated with respect to the amount of raw silicon source) were poured into a mortar and mixed by grinding for 10 minutes. The mixture than was transferred into a polytetrafluorethylene lined stainless steel autoclave and the crystallization was conducted at 200 C. for 5 hours until the crystallization was complete. The product was filtered by suction filtration followed by a drying step to obtain the final product in a powder form. The composition of the synthetic mixture is as follows:
(54) SiO.sub.2:0.034 Al.sub.2O.sub.3:0.19 Na.sub.2O:2.3 H.sub.2O. The mass ratio of seed crystals to the raw silicon source is 10%. It is determined by the X-ray diffraction analysis that the obtained product is a ZSM-5 zeolite.
Example 6
Synthesis of ZSM-5 Zeolite at a Low Temperature in a Short Time
(55) 1.5 g of Na.sub.2SiO.sub.3.9H.sub.2O, 0.65 g of Al.sub.2(SO.sub.4).sub.3.18H.sub.2O, 1.35 g of solid silica gel and 0.17 g of ZSM-5 seed crystals (the amount of seed crystals is calculated with respect to the amount of raw silicon source) were poured into a mortar and mixed by grinding for 10 minutes. The mixture than was transferred into a polytetrafluorethylene lined stainless steel autoclave and the crystallization was conducted at 150 C. for 4 days until the crystallization was complete. The product was filtered by suction filtration and followed by a drying step to obtain the final product in a powder form. The composition of the synthetic mixture is as follows:
(56) SiO.sub.2:0.034 Al.sub.2O.sub.3:0.19 Na.sub.2O:2.3 H.sub.2O. The mass ratio of seed crystals to the raw silicon source is 10%. It is determined by the X-ray diffraction analysis that the obtained product is a ZSM-5 zeolite.
Example 7
Synthesis of ZSM-5 Zeolite Using 1% Seed Crystals
(57) 1.5 g of Na.sub.2SiO.sub.3.9H.sub.2O, 0.65 g of Al.sub.2(SO.sub.4).sub.3.18H.sub.2O, 1.35 g of solid silica gel and 0.017 g of ZSM-5 seed crystals (the amount of seed crystals is calculated with respect to the amount of raw silicon source) were poured into a mortar and mixed by grinding for 10 minutes. The mixture than was transferred into a polytetrafluorethylene lined stainless steel autoclave and the crystallization was conducted at 180 C. for 1 day until the crystallization was complete. The product was filtered by suction filtration and followed by a drying step to obtain the final product in a powder form. The composition of the synthetic mixture is as follows:
(58) SiO.sub.2:0.034 Al.sub.2O.sub.3:0.19 Na.sub.2O:2.3 H.sub.2O. The mass ratio of seed crystals to the raw silicon source is 1%. It is determined by the X-ray diffraction analysis that the obtained product is a ZSM-5 zeolite.
Example 8
Synthesis of ZSM-5 Zeolite Using 5% Seed Crystals
(59) 1.5 g of Na.sub.2SiO.sub.3.9H.sub.2O, 0.65 g of Al.sub.2(SO.sub.4).sub.3.18H.sub.2O, 1.35 g of solid silica gel and 0.085 g of ZSM-5 seed crystals (the amount of seed crystals is calculated with respect to the amount of raw silicon source) were poured into a mortar and mixed by grinding for 10 minutes. The mixture was then transferred into a polytetrafluorethylene lined stainless steel autoclave and the crystallization was conducted at 180 C. for 20 hours until the crystallization was complete. The product was filtered by suction filtration and followed by a drying step to obtain the final product in a powder form. The composition of the synthetic mixture is as follows:
(60) SiO.sub.2:0.034 Al.sub.2O.sub.3:0.19 Na.sub.2O:2.3 H.sub.2O. The mass ratio of seed crystals to the raw silicon source is 5%. It is determined by the X-ray diffraction analysis that the obtained product is a ZSM-5 zeolite.
Example 9
Synthesis of Beta Zeolite at a Low Temperature by the Organotemplate-free Solid-state Method
(61) 6.34 g of SiO.sub.2.3H.sub.2O, 0.73 g of NaAlO.sub.2, 0.48 g of NaOH and 0.34 g of Beta seed crystals (the amount of seed crystals is calculated with respect to the amount of raw silicon source) were poured into a mortar and mixed by grinding for 10 minutes. The mixture was then transferred into a polytetrafluorethylene lined stainless steel autoclave and the crystallization was conducted at 120 C. for 10 days until the crystallization was complete. The product was filtered by suction filtration and followed by a drying step to obtain the final product in a powder form. The composition of the synthetic mixture is as follows:
(62) SiO.sub.2:0.056 Al.sub.2O.sub.3:0.2 Na.sub.2O:3 H.sub.2O. The mass ratio of seed crystals to the raw silicon source is 10%. It is determined by the X-ray diffraction analysis that the obtained product is a Beta zeolite.
Example 10
Synthesis of Beta Zeolite at a High Temperature by the Organotemplate-free Solid-state Method
(63) 6 g of SiO2.3H2O, 1.09 g of NaAlO.sub.2, 0.19 g of NaOH and 0.4 g of Beta seed crystals (the amount of seed crystals is calculated with respect to the amount of raw silicon source) were poured into a mortar and mixed by grinding for 10 minutes. The mixture than was transferred into a polytetrafluorethylene lined stainless steel autoclave and the crystallization was conducted at 140 C. for 3 days until the crystallization was complete. The product was filtered by suction filtration and followed by a drying step to obtain the final product in a powder form. The composition of the synthetic mixture is as follows:
(64) SiO.sub.2:0.083 Al.sub.2O.sub.3:0.14 Na.sub.2O:2.5 H.sub.2O. The mass ratio of seed crystals to the raw silicon source is 10%. It is determined by the X-ray diffraction analysis that the obtained product is a Beta zeolite.
Example 11
Synthesis of Beta Zeolite Using 5% Seed Crystals
(65) 6.34 g of SiO.sub.2.3H.sub.2O, 0.76 g of NaAlO.sub.2, 0.45 g of NaOH and 0.17 g of Beta seed crystals (the amount of seed crystals is calculated with respect to the amount of raw silicon source) were poured into a mortar and mixed by grinding for 10 minutes. The mixture was then transferred into a polytetrafluorethylene lined stainless steel autoclave and the crystallization was conducted at 120 C. for 15 days until the crystallization was complete. The product was filtered by suction filtration and followed by a drying step to obtain the final product in a powder form. The composition of the synthetic mixture is as follows:
(66) SiO.sub.2:0.06 Al.sub.2O.sub.3:0.18 Na.sub.2O:3 H.sub.2O. The mass ratio of seed crystals to the raw silicon source is 5%. It is determined by the X-ray diffraction analysis that the obtained product is a Beta zeolite.
Example 12
Synthesis of Beta zeolite using 1% seed crystals
(67) 6.34 g of SiO.sub.2.3H.sub.2O, 0.73 g of NaAlO.sub.2, 0.48 g of NaOH and 0.034 g of Beta seed crystals (the amount of seed crystals is calculated with respect to the amount of raw silicon source) were poured into a mortar and mixed by grinding for 10 minutes. The mixture was then transferred into a polytetrafluorethylene lined stainless steel autoclave and the crystallization was conducted at 120 C. for 20 days until the crystallization was complete. The product was filtered by suction filtration and followed by a drying step to obtain the final product in a powder form. The composition of the synthesis gel is as follows:
(68) SiO.sub.2:0.056 Al.sub.2O.sub.3:0.19 Na.sub.2O:3 H.sub.2O. The mass ratio of seed crystals to silicon source is 1%. It is determined by the X-ray diffraction analysis that the obtained product is a Beta zeolite.
Example 13
Synthesis of FAU Zeolite by the Organotemplate-free Solid-state Method
(69) 3.17 g of SiO.sub.2.3H.sub.2O and 1.64 g of NaAlO.sub.2 were poured into a mortar and mixed by grinding for 10 minutes. The mixture was then transferred into a polytetrafluorethylene lined stainless steel autoclave and aged for 20 hours. The crystallization was conducted at 100 C. for 1 day until the crystallization was complete. The product was filtered by suction filtration and followed by a drying step to obtain the final product in a powder form. The composition of the synthetic mixture is as follows:
(70) SiO.sub.2:0.25 Al.sub.2O.sub.3:0.39 Na.sub.2O:3 H.sub.2O. It is determined by the X-ray diffraction analysis that the obtained product is a FAU zeolite.
Example 14
Synthesis of FAU Zeolite by the Organotemplate-free Solid-state Method
(71) 3 g of SiO.sub.2.2.5H.sub.2O and 1.64 g of NaAlO.sub.2 were poured into a mortar and mixed by grinding for 10 minutes. The mixture was then placed into a polytetrafluorethylene lined stainless steel autoclave and aged for 20 hours. The crystallization was conducted at 100 C. for 1 day until the crystallization was complete. The product was filtered by suction filtration and followed by a drying step to obtain the final product in a powder form. The composition of the synthetic mixture is as follows:
(72) SiO.sub.2:0.25 Al.sub.2O.sub.3:0.39 Na.sub.2O:2.5 H.sub.2O. It is determined by the X-ray diffraction analysis that the obtained product is a FAU zeolite.
Example 15
Synthesis of FAU Zeolite at a High Temperature by the Organotemplate-free Solid-state Method
(73) 2.67 g of SiO.sub.2.2H.sub.2O and 1.64 g of NaAlO.sub.2 were poured into a mortar and mixed by grinding for 10 minutes. The mixture was then transferred into a polytetrafluorethylene lined stainless steel autoclave and aged for 20 hours. The crystallization was conducted at 120 C. for 12 hours until the crystallization was complete. The product was filtered by suction filtration and followed by a drying step to obtain the final product in a powder form. The composition of the synthetic mixture is as follows:
(74) SiO.sub.2:0.25 Al.sub.2O.sub.3:0.39 Na.sub.2O:2 H.sub.2O. It is determined by the X-ray diffraction analysis that the obtained product is a FAU zeolite.
Example 16
Synthesis of FAU Zeolite at a Low Temperature by the Organotemplate-free Solid-state Method
(75) 3.17 g of SiO.sub.2.3H.sub.2O and 1.64 g of NaAlO.sub.2 were poured into a mortar and mixed by grinding for 10 minutes. The mixture was then placed into a polytetrafluorethylene lined stainless steel autoclave and aged for 20 hours. The crystallization was conducted at 80 C. for 3 days until the crystallization was complete. The product was filtered by suction filtration and followed by a drying step to obtain the final product in a powder form. The composition of the synthetic mixture is as follows:
(76) SiO.sub.2:0.25 Al.sub.2O.sub.3:0.39 Na.sub.2O:3 H.sub.2O. It is determined by the X-ray diffraction analysis that the obtained product is a FAU zeolite.
Example 17
Synthesis of MOR Zeolite by the Organotemplate-free Solid-state Method
(77) 3.27 g of SiO.sub.2.3H.sub.2O, 0.363 g of NaAlO.sub.2 and 0.125 g of NaOH were poured into a mortar and mixed by grinding for 10 minutes. The mixture was then transferred into a polytetrafluorethylene lined stainless steel autoclave and the crystallization was conducted at 160 C. for 2.5 days until the crystallization was complete. The product was filtered by suction filtration and followed by a drying step to obtain the final product in a powder form. The composition of the synthetic mixture is as follows:
(78) SiO.sub.2:0.05 Al.sub.2O.sub.3:0.15 Na.sub.2O:3 H.sub.2O. It is determined by the X-ray diffraction analysis that the obtained product is a MOR zeolite.
Example 18
Synthesis of MOR Zeolite by the Organotemplate-free Solid-state Method
(79) 3 g of SiO.sub.2.2.5H.sub.2O, 0.363 g of NaAlO.sub.2 and 0.13 g of NaOH were poured into a mortar and mixed by grinding for 10 minutes. The mixture was then placed into a polytetrafluorethylene lined stainless steel autoclave and the crystallization was conducted at 160 C. for 2.5 days until the crystallization was complete. The product was filtered by suction filtration and followed by a drying step to obtain the final product in a powder form. The composition of the synthetic mixture is as follows:
(80) SiO.sub.2:0.05 Al.sub.2O.sub.3:0.16 Na.sub.2O:2.5 H.sub.2O. It is determined by the X-ray diffraction analysis that the obtained product is a MOR zeolite.
Example 19
Synthesis of MOR Zeolite at a Low Temperature by the Organotemplate-free Solid-state Method
(81) 3.17 g of SiO.sub.2.3H.sub.2O, 0.363 g of NaAlO.sub.2 and 0.125 g of NaOH were poured into a mortar and mixed by grinding for 10 minutes. The mixture was then placed into a polytetrafluorethylene lined stainless steel autoclave and the crystallization was conducted at 140 C. for 7 days until the crystallization was complete. The product was filtered by suction filtration and followed by a drying step to obtain the final product in a powder form. The composition of the synthetic mixture is as follows:
(82) SiO.sub.2:0.05 Al.sub.2O.sub.3:0.15 Na.sub.2O:2 H.sub.2O. It is determined by the X-ray diffraction analysis that the obtained product is a MOR zeolite.
Example 20
Synthesis of MOR Zeolite at a Relatively High Temperature by the Organotemplate-free Solid-state Method
(83) 3.17 g of SiO.sub.2.3H.sub.2O, 0.363 g of NaAlO.sub.2 and 0.08 g of NaOH were poured into a mortar and mixed by grinding for 10 minutes. The mixture was then transferred into a polytetrafluorethylene lined stainless steel autoclave and the crystallization was conducted at 180 C. for 1.5 days until the crystallization was complete. The product was filtered by suction filtration and followed by a drying step to obtain the final product in a powder form. The composition of the synthetic mixture is as follows:
(84) SiO.sub.2:0.05 Al.sub.2O.sub.3:0.1 Na.sub.2O:2 H.sub.2O. It is determined by the X-ray diffraction analysis that the obtained product is a MOR zeolite.
Example 21
Synthesis of GIS Zeolite by the Organotemplate-free Solid-state Method
(85) 2 g of NaSiO.sub.3.9H.sub.2O, 0.655 g of NaAlO.sub.2 and 1.25 g of SiO.sub.2 were poured into a mortar and mixed by grinding for 10 minutes. The mixture was then transferred into a polytetrafluorethylene lined stainless steel autoclave and the crystallization was conducted at 120 C. for 10 hours until the crystallization was complete. The product was filtered by suction filtration and followed by a drying step to obtain the final product in a powder form. The composition of the synthetic mixture is as follows:
(86) SiO.sub.2:0.1 Al.sub.2O.sub.3:0.39 Na.sub.2O:2.5 H.sub.2O. It is determined by the X-ray diffraction analysis that the obtained product is a GIS zeolite.
Example 22
Synthesis of GIS Zeolite by the Organotemplate-free Solid-state Method
(87) 1.7 g of NaSiO.sub.3.9H.sub.2O, 0.655 g of NaAlO.sub.2 and 1.25 g of SiO.sub.2 were poured into a mortar and mixed by grinding for 10 minutes. The mixture was then transferred into a polytetrafluorethylene lined stainless steel autoclave and the crystallization was conducted at 120 C. for 10 hours until the crystallization was complete. The product was filtered by suction filtration and followed by a drying step to obtain the final product in a powder form. The composition of the synthetic mixture is as follows:
(88) SiO.sub.2:0.1 Al.sub.2O.sub.3:0.39 Na.sub.2O:2 H.sub.2O. It is determined by the X-ray diffraction analysis that the obtained product is a GIS zeolite.
Example 23
Synthesis of GIS Zeolite by the Organotemplate-free Solid-state Method
(89) 2.5 g of NaSiO.sub.3.9H.sub.2O, 0.655 g of NaAlO.sub.2 and 1.25 g of SiO.sub.2 were poured into a mortar and mixed by grinding for 10 minutes. The mixture than was placed into a polytetrafluorethylene lined stainless steel autoclave and the crystallization was conducted at 120 C. for 10 hours until the crystallization was complete. The product was filtered by suction filtration and followed by a drying step to obtain the final product in a powder form. The composition of the synthetic mixture is as follows:
(90) SiO.sub.2:0.1 Al.sub.2O.sub.3:0.39 Na.sub.2O:3 H.sub.2O. It is determined by the X-ray diffraction analysis that the obtained product is a GIS zeolite.
Example 24
Synthesis of LTA Zeolite by the Organotemplate-free Solid-state Method
(91) 3.67 g of SiO.sub.2.4H.sub.2O and 3.27 g of NaAlO.sub.2 were poured into a mortar and mixed by grinding for 10 minutes. The mixture was then transferred into a polytetrafluorethylene lined stainless steel autoclave and the crystallization was conducted at 50 C. for 35 hours until the crystallization was complete. The product was filtered by suction filtration and followed by a drying step to obtain the final product in a powder form. The composition of the synthetic mixture is as follows:
(92) SiO.sub.2:0.5 Al.sub.2O.sub.3:0.69 Na.sub.2O:4 H.sub.2O. It is determined by the X-ray diffraction analysis that the obtained product is a LTA zeolite.
Example 25
Synthesis of LTA Zeolite by the Organotemplate-free Solid-state Method
(93) 3.17 g of SiO.sub.2.3H.sub.2O and 3.27 g of NaAlO.sub.2 were poured into a mortar and mixed by grinding for 10 minutes. The mixture was then transferred into a polytetrafluorethylene lined stainless steel autoclave and the crystallization was conducted at 50 C. for 35 hours until the crystallization was complete. The product was filtered by suction filtration and followed by a drying step to obtain the final product in a powder form. The composition of the synthetic mixture is as follows:
(94) SiO.sub.2:0.5 Al.sub.2O.sub.3:0.69 Na.sub.2O:3 H.sub.2O. It is determined by the X-ray diffraction analysis that the obtained product is a LTA zeolite.
Example 26
Synthesis of LTA Zeolite by the Organotemplate-free Solid-state Method
(95) 3.42 g of SiO.sub.2.3.5H.sub.2O and 3.27 g of NaAlO.sub.2 were poured into a mortar and mixed by grinding for 10 minutes. The mixture was then transferred into a polytetrafluorethylene lined stainless steel autoclave and the crystallization was conducted at 50 C. for 35 hours until the crystallization was complete. The product was filtered by suction filtration and followed by a drying step to obtain the final product in a powder form. The composition of the synthetic mixture is as follows:
(96) SiO.sub.2:0.5 Al.sub.2O.sub.3:0.69 Na.sub.2O:3.5 H.sub.2O. It is determined by the X-ray diffraction analysis that the obtained product is a LTA zeolite.
Example 27
Organotemplate-free Synthesis of Beta Zeolite without Addition of Water as Solvent
(97) 6.34 g of SiO.sub.2.3H.sub.2O (hydrated form of solid silica gel), 0.73 g of NaAlO.sub.2, 0.48 g of NaOH, and 0.34 g of Beta seeds were added together. After grinding for 10-20 minutes, the powder mixture was transferred to an autoclave and sealed. After heating at 120 C. for 9 days, the sample was completely crystallized. The H-form of the sample was prepared by ion-exchange with 1 M NH.sub.4NO.sub.3 solution and calcination at 500 C. for 4 hours. The ion-exchange procedure was repeated for 1 time.
(98)
(99) Beta zeolite obtained from Example 27 was further tested with respect to its catalytic activity in cumene cracking, which was performed at 300 C. by pulse injections. In each run, 50 mg of the zeolite sample was used as the catalyst, the pulse injection of the reactant was 0.4 mL, and the reaction flow rate was 55 mL/min. For comparison, a Beta zeolite sample obtained according to a conventional procedure employing an organotemplate was also tested under the same conditions. As may be taken from the results from catalytic testing of both samples under the given conditions which are displayed in
Example 28
Organotemplate-free Synthesis of ZSM-5 Zeolite without Addition of Water as Solvent
(100) 1.5 g of NaSiO.sub.3.9H.sub.2O (SiO.sub.2, 20 wt. %), 0.65 g of Al.sub.2(SO.sub.4).sub.3.18H.sub.2O, 1.35 g of solid silica gel, and 0.17 g of ZSM-5 seeds were added together. After grinding for 10-20 minutes, the powder mixture was transferred to an autoclave and sealed. After heating at 180 C. for 13 hours, the sample was completely crystallized. The H-form of the sample was prepared from ion-exchange with 1 M NH.sub.4NO.sub.3 solution and calcination at 500 C. for 4 hours. The ion-exchange procedure was repeated for 1 time.
(101)
(102) ZSM-5 obtained from Example 28 was further tested with respect to its catalytic activity in m-xylene isomerization to p-xylene, which was carried out in a fixed-bed reactor. The zeolite sample (200 mg, 20-40 mesh) was first activated in dry air at 450 C. for 2 h and then cooled to reaction temperature (350 C.) in a flow of dry nitrogen. m-xylene was fed (WHSV=3 h.sup.1) by a metering pump, vaporized in a preheated assembly and then passed through the catalyst. The product was analyzed by on-line gas chromatography (GC1690) with FID detector using HP-FFAP column. For comparison, a ZSM-5 sample obtained according to a conventional procedure employing an organotemplate was also tested under the same conditions. As may be taken from the results from catalytic testing of both samples under the given conditions which are displayed in