U.S. patent number 10,099,932 [Application Number 15/505,490] was granted by the patent office on 2018-10-16 for rapid synthesis method of small-crystal-grain zsm-5 molecular sieve.
This patent grant is currently assigned to DALIAN UNIVERSITY OF TECHNOLOGY, RESEARCH INSTITUTE OF SHAANXI YANCHANG PETROLEUM (GROUP) CO., LTD.. The grantee listed for this patent is DALIAN UNIVERSITY OF TECHNOLOGY, RESEARCH INSTITUTE OF SHAANXI YANCHANG PETROLEUM (GROUP) CO., LTD. Invention is credited to Gang Chen, Ruimin Gao, Pengju Huo, Dapeng Li, Si Li, Haiou Liu, Zhiling Liu, Yongbin Lu, Ting Pei, Chengda Wang, Mingfeng Wang, Weiwu Xu, Hua Zhang, Shuqin Zhang, Wei Zhang, Xiongfu Zhang, Yuan Zhang.
United States Patent |
10,099,932 |
Zhang , et al. |
October 16, 2018 |
Rapid synthesis method of small-crystal-grain ZSM-5 molecular
sieve
Abstract
A rapid synthesis method of a small-crystal-grain ZSM-5
molecular sieve, the method comprising: preparing a mixed
silicon-aluminum glue solution, placing the solution in a
crystallization kettle for low-temperature nucleation, enabling
high-temperature crystallization growth of the solution, and
obtaining a crystallization product, namely, a small-crystal-grain
ZSM-5 molecular sieve, the nucleation temperature being
60-120.degree. C., nucleation time being 1-3 hours, a
crystallization growth temperature being 150-170.degree. C., and
crystallization growth time being 1-3 hours. The method is easy to
operate, and has a short operation time, thus being able to
complete within 6 hours; in addition, the product has uniform grain
sizes, is in a mono-dispersed state, and has a high crystallization
degree to a submicron degree.
Inventors: |
Zhang; Wei (Xi'an,
CN), Zhang; Xiongfu (Xi'an, CN), Li;
Dapeng (Xi'an, CN), Gao; Ruimin (Xi'an,
CN), Lu; Yongbin (Xi'an, CN), Zhang;
Shuqin (Xi'an, CN), Wang; Mingfeng (Xi'an,
CN), Huo; Pengju (Xi'an, CN), Li; Si
(Xi'an, CN), Wang; Chengda (Xi'an, CN), Xu;
Weiwu (Xi'an, CN), Zhang; Yuan (Xi'an,
CN), Liu; Zhiling (Xi'an, CN), Pei;
Ting (Xi'an, CN), Zhang; Hua (Xi'an,
CN), Chen; Gang (Xi'an, CN), Liu; Haiou
(Xi'an, CN) |
Applicant: |
Name |
City |
State |
Country |
Type |
RESEARCH INSTITUTE OF SHAANXI YANCHANG PETROLEUM (GROUP) CO.,
LTD
DALIAN UNIVERSITY OF TECHNOLOGY |
Xi'an, Shaanxi
Dalian, Liaoning Province |
N/A
N/A |
CN
CN |
|
|
Assignee: |
RESEARCH INSTITUTE OF SHAANXI
YANCHANG PETROLEUM (GROUP) CO., LTD. (Shaanxi, CN)
DALIAN UNIVERSITY OF TECHNOLOGY (Dalian, CN)
|
Family
ID: |
52078282 |
Appl.
No.: |
15/505,490 |
Filed: |
July 14, 2015 |
PCT
Filed: |
July 14, 2015 |
PCT No.: |
PCT/CN2015/083940 |
371(c)(1),(2),(4) Date: |
February 21, 2017 |
PCT
Pub. No.: |
WO2016/041404 |
PCT
Pub. Date: |
March 24, 2016 |
Prior Publication Data
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|
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Document
Identifier |
Publication Date |
|
US 20170233259 A1 |
Aug 17, 2017 |
|
Foreign Application Priority Data
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|
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Aug 21, 2014 [CN] |
|
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2014 1 0414006 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C01B
39/40 (20130101); C01P 2004/62 (20130101); C01P
2002/60 (20130101); C01P 2004/60 (20130101); C01P
2002/72 (20130101); B01J 29/40 (20130101); C01P
2004/03 (20130101) |
Current International
Class: |
C01B
39/40 (20060101); B01J 29/40 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1240193 |
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Jan 2000 |
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CN |
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1958453 |
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May 2007 |
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CN |
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101279746 |
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Oct 2008 |
|
CN |
|
101182004 |
|
May 2010 |
|
CN |
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102826568 |
|
Dec 2012 |
|
CN |
|
104150507 |
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Nov 2014 |
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CN |
|
104192859 |
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Dec 2014 |
|
CN |
|
Other References
Oct. 19, 2015 Search Report issued in International Patent
Application No. PCT/CN2015/083940. cited by applicant .
Oct. 19, 2015 Written Opinion issued in International Patent
Application No. PCT/CN2015/083940. cited by applicant .
Sep. 6, 2015 Office Action issued in Chinese Patent Application No.
201410414006.3. cited by applicant .
Apr. 19, 2016 Office Action issued in Chinese Patent Application
No. 201410414006.3. cited by applicant .
Oct. 19, 2016 Office Action issued in Chinese Patent Application
No. 201410414006.3. cited by applicant.
|
Primary Examiner: Brunsman; David M
Attorney, Agent or Firm: Oliff PLC
Claims
The invention claimed is:
1. A rapid method of synthesizing a small-crystal-grain ZSM-5
molecular sieve, wherein a mixed colloidal solution of silicon and
aluminum is prepared, and then the mixed colloidal solution is
loaded into a crystallization kettle for nucleation at a low
temperature and subsequently subjected to a crystallization growth
at a high temperature, the obtained crystallization product is the
small-crystal-grain ZSM-5 molecular sieve, wherein the nucleation
temperature is within a range of from 60 to 120.degree. C., and the
nucleation time is from 1 to 3 h; the crystallization growth
temperature is within a range of from 150 to 170.degree. C., and
the crystallization growth time is from 1 to 3 h.
2. The rapid method of synthesizing a small-crystal-grain ZSM-5
molecular sieve according to claim 1, wherein the nucleation
temperature is within a range of from 100 to 120.degree. C., and
the nucleation time is 1 h; the crystallization growth temperature
is within a range of from 160 to 170.degree. C., and the
crystallization growth time is 1 h.
3. The rapid method of synthesizing a small-crystal-grain ZSM-5
molecular sieve according claim 1, wherein the drying temperature
is 120.degree. C., the roasting temperature is 540.degree. C., and
roasting time is 6 h.
4. The rapid method of synthesizing a small-crystal-grain ZSM-5
molecular sieve according to claim 1, wherein the particle size of
the small crystal grain is from 270 to 450 nm.
5. The rapid method of synthesizing a small-crystal-grain ZSM-5
molecular sieve according to claim 4, wherein a molar ratio of the
SiO.sub.2 in the silicon source to the "Al.sub.2O.sub.3 in the
aluminum source is from 40 to 100.
6. The rapid method of synthesizing a small-crystal-grain ZSM-5
molecular sieve according to claim 4, wherein the organic
templating agent is tetrapropylammonium hydroxide.
7. The rapid method of synthesizing a small-crystal-grain ZSM-5
molecular sieve according to claim 4, wherein the silicon source is
ethyl orthosilicate.
8. The rapid method of synthesizing a small-crystal-grain ZSM-5
molecular sieve according to claim 4, wherein the aluminum source
is sodium aluminate.
9. The rapid method of synthesizing a small-crystal-grain ZSM-5
molecular sieve according to claim 1, wherein the mixed colloidal
solution of silicon and aluminum is prepared as follows: first
mixing an organic templating agent, an aluminum source and water,
then adding a silicon source, mixing well to allow a hydrolysis, so
as to form a uniform mixed colloidal solution of silicon and
aluminum.
10. The rapid method of synthesizing a small-crystal-grain ZSM-5
molecular sieve according to claim 4, wherein the crystallization
product further undergoes washing, drying and roasting.
Description
TECHNICAL FIELD
The present invention relates to a method for preparing a ZSM-5
molecular sieve.
BACKGROUND ART
Due to its excellent performance, zeolite molecular sieves have a
wide range of applications in refining, petrochemical, organic
synthesis and many other fields. Among zeolite molecular sieves, a
ZSM-5 molecular sieve has good catalytic activity, stability and
shape selectivity because of its unique pore structure. In
addition, when compared with a large-crystal-grain ZSM-5 molecular
sieve, a small-crystal-grain molecular sieve has an even larger
external surface area, which allows more active center to be
exposed on the external surface. Moreover, a small-crystal-grain
molecular sieve has short intra-crystalline porous channels. As a
result, reactant molecules and product molecules have a lower
diffusion resistance and high diffusion rate in the porous
channels. A small-crystal-grain molecular sieve has short
intra-crystalline porous channels and high diffusion rate in the
channels. Accordingly, the generated reaction product can quickly
diffuse out from the channels, which can prevent it from having any
side reaction, and accordingly it helps to improve the selectivity
of the product. On the other hand, a small-crystal-grain molecular
sieve can help to reduce carbon deposition in channels and reduce
catalyst coking and deactivation. The small-crystal-grain ZSM-5
molecular sieve has shown relatively good catalytic performance in
most catalytic reactions, in which it has greatly improved the
activity and selectivity of catalysts. However, on the other hand,
the synthesis of the ZSM-5 molecular sieve typically has problems
including complex synthetic process and long synthetic period. As a
result, the rapid synthesis of the small-crystal-grain ZSM-5
molecular sieve has important practical significance.
To date, there are many reports on the synthesis of the
small-crystal-grain ZSM-5 molecular sieve. The primary approaches
employed in the preparation are shown in the following aspects: 1)
Add nanoscale zeolite seeds into the synthetic system to synthesize
a directing agent, so as to induce the formation of the
small-crystal-grain ZSM-5 molecular sieve. In CN1958453A, a silicon
source is dissolved in an acidic solution, and then add a
templating agent; next slowly add the aqueous solution of aluminum
source in the solution of silicon source, and at the same time, add
the molecular sieve seed, and then carry out a hydrothermal
crystallization process at a temperature of 100 to 200.degree. C.
for 10 to 60 h, so as to obtain a ZSM-5 molecular sieve having a
particle size within the range of from 100 to 400 nm. (2) Introduce
an inorganic salt or surfactant, etc. into the synthetic system to
regulate the synthesis of the small-crystal-grain ZSM-5 molecular
sieve. CN101182004B discloses a process for preparing a synthetic
nanoscale molecular sieve, in which a hydrocarbon component and a
surfactant are added into a precursor solution, so as to form an
oil-coated melt super-compatibilizer system to effectively control
the growth of the molecular sieve. (3) Regulate and control the
synthetic condition, in particular using a low temperature to
facilitate nucleus formation, so as to form a small-crystal-grain
ZSM-5 molecular sieve. CN101279746 proposes to employ a variable
temperature crystallization method to form the ZSM-5 molecular
sieve, in which a short chain amine is used as the template, and
the reaction mixture is first aged at a temperature of 115 to
125.degree. C. for 1 to 4 h, and then transferred to a temperature
of 230 to 250.degree. C. for crystallization 4 to 8 h. The sizes of
the crystal grains of the ZSM-5 molecular sieves prepared through
the process mentioned above are various, from dozens of nanometers
to hundreds of nanometers. However, the synthetic process and
preparation processes are quite complex and the time period of the
process is very long, at least longer than 10 h. In addition, the
products can be formed only when adding the crystal seeds and other
materials. The entire preparation process is time- and energy
consuming, and thus wastes lots of energy, time and at the same
time, contaminates the environment.
In our prior patent entitled "One-step preparation method for empty
shell-type small-grain ZSM-5 molecular sieve" (Patent no.:
201410361785.5), the empty shell-type small-grain ZSM-5 molecular
sieve is obtained by way of regulating the synthesis solution and
crystallization growth process. However, this method needs a long
time period for synthesis, which is typically 24 h (at least longer
than 6 h). In addition, the preparation process is relatively time-
and energy consuming.
TECHNICAL PROBLEM
The present invention aims to provide a rapid synthesis method
which features a very short crystallization time and a product that
is a submicron small-crystal-grain ZSM-5 molecular sieve with high
crystallinity.
SOLUTION FOR THE PROBLEM
Technical Solution
The present invention provides a rapid synthesis method of the
small-crystal-grain ZSM-5 molecular sieve. First, a mixed colloidal
solution of silicon and aluminum is prepared, and then the mixed
colloidal solution is loaded into a crystallization kettle for
nucleation at a low temperature and subsequently subjected to a
crystallization growth at a high temperature; the obtained
crystallization product is the small-crystal-grain ZSM-5 molecular
sieve, wherein the nucleation temperature is within a range of from
60 to 120.degree. C., and the nucleation time is from 1 to 3 h; the
crystallization growth temperature is within a range of from 150 to
170.degree. C., and the crystallization growth time is from 1 to 3
h.
Preferably, the nucleation temperature is within a range of from
100 to 120.degree. C., and the nucleation time is 1 h; the
crystallization growth temperature is within a range of from 160 to
170.degree. C., and the crystallization growth time is 1 h.
More preferably, the particle size of the small crystal grain is
from 270 to 450 nm.
Or more preferably, the mixed colloidal solution of silicon and
aluminum is prepared as follows: first mixing an organic templating
agent, an aluminum source and water, then adding a silicon source,
mixing well to allow a hydrolysis, so as to form a uniform mixed
colloidal solution of silicon and aluminum.
Or more preferably, a molar ratio of the SiO.sub.2 in the silicon
source to the "Al.sub.2O.sub.3 in the aluminum source is from 40 to
100.
Or more preferably, the organic templating agent is
tetrapropylammonium hydroxide.
Or more preferably, the silicon source is ethyl orthosilicate.
Or more preferably, the aluminum source is sodium aluminate.
Furthermore, preferably, the crystallization product further
undergoes washing, drying and roasting.
Most preferably, the drying temperature is 120.degree. C., the
roasting temperature is 540.degree. C., and roasting time is 6
h.
For the purpose of addressing the deficiencies in the current
preparation processes for the small-crystal-grain ZSM-5 molecular
sieve, a simple method for rapid preparation of the
small-crystal-grain ZSM-5 molecular sieve is proposed in the
present application. The preparation process has the advantages of
simple operation and short synthesis period. In addition, the
synthesis process does not require addition of any other substance.
The submicron small-crystal-grain ZSM-5 molecular sieve obtained
from the rapid synthesis process has a uniform particle size
distribution and high crystallinity.
Advantageous Effects of the Present Invention
The entire operation process of the present invention is very
simple, and the synthesis can be finished within 6 h, which is a
very short time period. In addition, the obtained
small-crystal-grain ZSM-5 molecular sieve has desirable particle
size distribution at the submicron scale, a single dispersion
state, a high crystallinity.
In addition, in some preferred embodiments of the present
invention, in addition to the raw materials in the formulation, no
other substance is needed. As a result, the synthesis of the
present invention is simple and can save materials. It allows the
obtaining of small-crystal-grain ZSM-5 zeolites with different
particle sizes by way of simply adjusting certain synthesis
conditions.
BRIEF DESCRIPTION OF THE DRAWINGS
Description of Drawings
FIG. 1 is the X-ray diffraction pattern of the sample synthesized
in Example 1.
FIG. 2 is a scanning electron micrograph of the sample synthesized
in Example 1.
FIG. 3 is a scanning electron micrograph of the sample synthesized
in Example 2.
FIG. 4 is a scanning electron micrograph of the sample synthesized
in Example 4.
FIG. 5 is a scanning electron micrograph of the sample synthesized
in Example 7.
FIG. 6 is a scanning electron micrograph of the sample synthesized
in Example 8.
FIG. 7 is a scanning electron micrograph of the sample synthesized
in Example 11.
INVENTION EXEMPLARY EMBODIMENTS
Embodiments of the Present Invention
EXAMPLE 1
Mix 17.6 g of the templating agent tetrapropylammonium hydroxide,
30 g of water, 0.2 g of sodium aluminate, and then add 16 mL ethyl
orthosilicate, mix for 2 h to obtain a uniform colloidal solution,
which is then loaded into a stainless steel crystallization kettle,
carry out a nucleation process at a temperature of 100.degree. C.
for 3 h, and then carry out a crystallization growth at a
temperature of 170.degree. C. for 3 h; the obtained product is then
filtered and washed, and subsequently dried at a temperature of
120.degree. C., and then roasted at a temperature of 540.degree. C.
for 6 h. FIG. 1 shows an X-ray diffraction (XRD) pattern of the
small-crystal-grain sample synthesized in this example. As shown in
the figure, the sample has shown the characteristic peaks of a
typical MFI-type zeolite. In addition, no impurity peaks have been
found, which indicates that the obtained product is a pure ZSM-5
molecular sieve. FIG. 2 is a scanning electron micrograph (SEM) of
the sample synthesized in this example. As shown in the figure, the
obtained small-crystal-grain ZSM-5 molecular sieve has a particle
size of 320 nanometers.
EXAMPLE 2
Repeat the operating procedures provided in Example 1 with the
exception that in this example, the nucleation process is carried
out at a temperature of 80.degree. C. for 3 h, and the
crystallization growth process is carried out at a temperature of
170.degree. C. for 3 h. The synthesized small-crystal-grain LSM-5
molecular sieve has a particle size of 270 nanometers.
EXAMPLE 3
Repeat the operating procedures provided in Example 1, with the
exception that in this example, the nucleation process is carried
out at a temperature of 120.degree. C. for 3 h, and the
crystallization growth process is carried out at a temperature of
170.degree. C. for 3 h. The synthesized small-crystal-grain ZSM-5
molecular sieve has a particle size of 390 nanometers.
EXAMPLE 4
Repeat the operating procedures provided in Example 1, with the
exception that in this example, the nucleation process is carried
out at a temperature of 100.degree. C. for 3 h, and the
crystallization growth process is carried out at a temperature of
150.degree. C. for 3 h. The synthesized small-crystal-grain ZSM-5
molecular sieve has a particle size of 290 nanometers.
EXAMPLE 5
Repeat the operating procedures provided in Example 1, with the
exception that in this example, the nucleation process is carried
out at a temperature of 100.degree. C. for 1 h, and the
crystallization growth process is carried out at a temperature of
170.degree. C. for 3 h. The synthesized small-crystal-grain ZSM-5
molecular sieve has a particle size of 390 nanometers.
EXAMPLE 6
Repeat the operating procedures provided in Example 1, with the
exception that in this example, the nucleation process is carried
out at a temperature of 100.degree. C. for 3 h, and the
crystallization growth process is carried out at a temperature of
170.degree. C. for 1 h. The synthesized small-crystal-grain ZSM-5
molecular sieve has a particle size of 280 nanometers.
EXAMPLE 7
Repeat the operating procedures provided in Example 1, with the
exception that in this example, the nucleation process is carried
out at a temperature of 100.degree. C. for 1 h, and the
crystallization growth process is carried out at a temperature of
170.degree. C. for 1 h. The synthesized small-crystal-grain ZSM-5
molecular sieve has a particle size of 330 nanometers.
EXAMPLE 8
Repeat the operating procedures provided in Example 1, with the
exception that in this example, the nucleation process is carried
out at a temperature of 120.degree. C. for 1 h, and the
crystallization growth process is carried out at a temperature of
160.degree. C. for 1 h. The synthesized small-crystal-grain ZSM-5
molecular sieve has a particle size of 300 nanometers.
EXAMPLE 9
Repeat the operating procedures provided in Example 1, with the
exception that in this example, the nucleation process is carried
out at a temperature of 110.degree. C. for 1 h, and the
crystallization growth process is carried out at a temperature of
168.degree. C. for 1 h. The synthesized small-crystal-grain ZSM-5
molecular sieve has a particle size of 350 nanometers.
EXAMPLE 10
Repeat the operating procedures provided in Example 1, with the
exception that in this example, the amount of the templating agent
added to the system is 23.5 mL, and the synthesized
small-crystal-grain ZSM-5 molecular sieve has a particle size of
270 nanometers.
EXAMPLE 11
Repeat the operating procedures provided in Example 1, with the
exception that in this example, the amount of the templating agent
added to the system is 11.7 mL, and the synthesized
small-crystal-grain ZSM-5 molecular sieve has a particle size of
450 nanometers.
EXAMPLE 10
Repeat the operating procedures provided in Example 1, with the
exception that in this example, the amount of sodium aluminate
added to the system is 0.3 g, and the synthesized
small-crystal-grain ZSM-5 molecular sieve has a particle size of
300 nanometers.
EXAMPLE 12
Repeat the operating procedures provided in Example 1, with the
exception that in this example, the amount of sodium aluminate
added to the system is 0.12 g, and the synthesized
small-crystal-grain ZSM-5 molecular sieve has a particle size of
270 nanometers.
EXAMPLE 13
Repeat the operating procedures provided in Example 1, with the
exception that in this example, the nucleation process is carried
out at a temperature of 60.degree. C. for 3 h, and the
crystallization growth process is carried out at a temperature of
170.degree. C. for 3 h. The synthesized small-crystal-grain ZSM-5
molecular sieve has a particle size of 400 nanometers.
* * * * *