U.S. patent application number 10/303697 was filed with the patent office on 2003-06-26 for catalysts for producing methylamines and method for manufacturing the same.
This patent application is currently assigned to Mitsubishi Gas Chemical Company, Inc.. Invention is credited to Hidaka, Toshio, Higuchi, Katsumi, Kawai, Takeshi.
Application Number | 20030120117 10/303697 |
Document ID | / |
Family ID | 17799007 |
Filed Date | 2003-06-26 |
United States Patent
Application |
20030120117 |
Kind Code |
A1 |
Hidaka, Toshio ; et
al. |
June 26, 2003 |
Catalysts for producing methylamines and method for manufacturing
the same
Abstract
Catalysts useful for producing methylamines and having practical
catalyst life and large selectivity for dimethylamine comprise
crystalline silicoaluminophosphate molecular sieves which have a
molar ratio of silicon atom to aluminum atom in the range of
0.01-0.30.
Inventors: |
Hidaka, Toshio;
(Tsukuba-Shi, JP) ; Higuchi, Katsumi;
(Tsukuba-Shi, JP) ; Kawai, Takeshi; (Tsukuba-Shi,
JP) |
Correspondence
Address: |
Kendrew H. Colton
FITCH, EVEN, TABIN & FLANNERY
Suite 401L
1801 K Street, N.W.
Washington
DC
20006-1201
US
|
Assignee: |
Mitsubishi Gas Chemical Company,
Inc.
|
Family ID: |
17799007 |
Appl. No.: |
10/303697 |
Filed: |
November 26, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10303697 |
Nov 26, 2002 |
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10191963 |
Jul 10, 2002 |
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10191963 |
Jul 10, 2002 |
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09559751 |
Apr 27, 2000 |
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6495724 |
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09559751 |
Apr 27, 2000 |
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09418605 |
Oct 15, 1999 |
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Current U.S.
Class: |
564/479 ;
502/208 |
Current CPC
Class: |
C07C 209/16 20130101;
B01J 35/023 20130101; B01J 29/85 20130101; C01B 37/08 20130101;
C07C 209/16 20130101; B01J 2229/42 20130101; C07C 211/04
20130101 |
Class at
Publication: |
564/479 ;
502/208 |
International
Class: |
C07C 29/16 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 15, 1998 |
JP |
293772/98 |
Claims
1. A catalyst for producing methylamines, which comprises a
crystalline silicoaluminophosphate molecular sieve, the molar ratio
of silicon atom to aluminum atom being in the range of
0.01-0.30.
2. The catalyst for producing methylamines according to claim 1,
wherein the molar ratio of silicon atom to aluminum atom is in the
range of 0.05-0.25.
3. The catalyst for producing methylamines according to claim 1 or
2, wherein the average particle size of crystals of the crystalline
silicoaluminophosphate molecular sieve is 5 .mu.m or less measured
by a scanning electron microscope.
4. The catalyst for producing methylamines according to claim 1,
wherein the crystalline silicoaluminophosphate molecular sieve has
a cubic, rectangular parallelepipedic, spheroidal, hexagonal or
prismatic form.
5. The catalyst for producing methylamines according to claim 1,
wherein the crystalline silicoaluminophosphate molecular sieve is
of H-type or of H-type in which a part of the H-type is replaced
with at least one metal selected from Li, Na, Be, Mg, Ca, Sr, Y,
Ti, Zr, V, Nb, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Zn, B,
Ga, In, Ge, and Sn, or the crystalline silicoaluminophosphate
molecular sieve contains the metal or an oxide of the metal.
6. The catalyst for producing methylamines according to claim 1,
wherein the crystalline silicoaluminophosphate molecular sieve is
SAPO-34 in which a part of the H-type is replaced with at least one
metal selected from Ti, Y and Zr or which contains the metal or an
oxide thereof.
7. The catalyst for producing methylamines according to claim 1,
wherein the crystalline silicoaluminophosphate molecular sieve
comprises at least one constituting component selected from SAPO-5,
11, 17, 18, 26, 31, 33, 34, 35, 42, 43, 44, 47 and 56.
8. A method for manufacturing a catalyst for producing methylamines
which comprises mixing an aluminum compound, a phosphorus compound,
a silicon compound, an amine or ammonium salt and water so that the
molar ratio of them satisfies the following formula (1) in case the
aluminum compound, the phosphorus compound and the silicon compound
are expressed by Al.sub.2O.sub.3, P.sub.2O.sub.5 and SiO.sub.2,
respectively, and then subjecting the mixture to a hydrothermal
treatment:
Al.sub.2O.sub.3.(1.+-.0.2)P.sub.2O.sub.5.(0.5.+-.0.4)SiO.sub.2.(1.5.+-.0.-
5)Am.(75.+-.25)H.sub.2O (1) wherein Am denotes an amine or ammonium
salt having 3 to 24 carbon atoms.
9. A method for manufacturing a catalyst for producing methylamines
which comprises mixing an aluminum compound, a phosphorus compound,
a silicon compound, an amine or ammonium salt and water with at
least one metal and/or a compound of the metal selected from Li,
Na, Be, Mg, Ca, Sr, Y, Ti, zr, V, Nb, Cr, Mn, Fe, Ru, Co, Rh, Ir,
Ni, Pd, Pt, Cu, Zn, B, Ga, In, Ge and Sn so that the molar ratio
satisfies the following formula (1) in case the aluminum compound,
the phosphorus compound and the silicon compound are expressed by
Al.sub.2O.sub.3, P.sub.2O.sub.5 and SiO.sub.2, respectively, and
then subjecting the mixture to a hydrothermal treatment:
Al.sub.2O.sub.3.(1.+-.0.2)P.sub.2O.sub.5.(0.5.+-.0.45)SiO.sub.-
2.(1.5.+-.0.5)Am.(75.+-.25)H.sub.2O (1) wherein Am denotes an amine
or ammonium salt having 3 to 24 carbon atoms.
10. A method for manufacturing a catalyst for producing
methylamines according to claim 8 or 9, wherein pseudo-boehmite is
used as the aluminum compound.
11. A method for producing methylamines which comprises allowing
methanol to react with ammonia in the presence of the crystalline
silicoaluminophosphate molecular sieve of claim 1.
12. A method for producing methylamines which comprises carrying
out a disproportionation reaction of monomethylamine in the
presence of the crystalline silicoaluminophosphate molecular sieve
of claim 1.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to catalysts for producing
methylamines and to method for manufacturing the catalysts.
Methylamines, particularly, dimethylamine are important as starting
materials for solvents represented by dimethylformamide, rubber
products, pharmaceuticals and surfactants.
[0003] 2. Description of the Prior Art
[0004] Methylamines are produced usually from methanol and ammonia
using solid acid catalysts such as silica-alumina, at a temperature
around 400.degree. C. Another known method comprises subjecting
monomethylamine to a disproportionation reaction. The main product
in the above methods for the production of methylamines is
trimethylamine which has the least demand. However, dimethylamine
is the most useful, and, therefore, methods for selectively
producing dimethylamine have been demanded.
[0005] Methods for producing methylamines using zeolites which are
more advantageous than conventional silica-alumina catalysts have
also been proposed. For example, these methods use zeolites such as
zeolite A (JP 56-69846 A), FU-1 (JP 54-148708 A), ZSM-5 (U.S. Pat.
No. 4,082,805), ferrierite and erionite (JP 56-113747 A), ZK-5,
Rho, chabazite and erionite (JP 61-254256 A), and mordenite (JP
56-46846 A, JP 58-49340 A, JP 59-210050 A, and JP 59-227841 A). In
addition, there is a method for producing methylamines in an amount
exceeding the thermodynamic equilibrium proportion, by using
silicoaluminophosphates (JP 2-734 A).
[0006] The present inventors filed patent applications, on the
basis of findings that silica-modified silicoaluminophosphates have
greater activity and selectivity for dimethylamine than known
zeolite catalysts and prior art silicoaluminophosphates (JP
Application Nos. 9-197232, 9-360124 and 10-025832). However, the
silica-modified silicoaluminophosphate catalysts have a problem of
decrease in initial activity, so that a further improvement in life
is demanded from a practical point of view.
SUMMARY OF THE INVENTION
[0007] The object of the present invention is to provide catalysts
for producing methylamines which have a practical catalyst life and
selectivity for dimethylamine and are free from the problem of
decrease in activity encountered in the silicoaluminophosphate
catalysts, and also methods for manufacturing the catalysts.
[0008] The inventors have found that crystalline
silicoaluminophosphates having specific properties and
compositional ratios which have never been referred to, in
particular, those which are replaced with specific elements or
those which are coated with the elements or oxides thereof have
smaller decrease of initial activity with time and are effectively
improved in catalyst life. As a result, a great improvement is
obtained in life of silicoaluminophosphates having excellent
initial activity and selectivity for dimethylamine as catalysts for
producing methylamines.
[0009] The present invention relates to crystalline
silicoalumonophosphate catalysts having improved life and being
useful as catalysts for producing methylamines which are mainly
composed of dimethylamine and produced by a reaction of methanol
with ammonia, a reaction of methanol with monomethylamine or a
disproportionation reaction of methylamines. The present invention
relates also to methods for manufacturing the catalysts.
[0010] In more detail, the present invention includes the following
aspects.
[0011] 1) The present invention relates to a catalyst for producing
methylamines which comprises a crystalline silicoaluminophosphate
molecular sieve having a molar ratio of silicon atom to aluminum
atom in the range of 0.01-0.30.
[0012] 2) The present invention further relates to a method for
manufacturing a catalyst for producing methylamines. It comprises
mixing an aluminum compound, a phosphorus compound, a silicon
compound, an amine or ammonium salt and water so that the molar
ratio of them satisfies the following formula (1) when the aluminum
compound, the phosphorus compound and the silicon compound are
expressed by Al.sub.2O.sub.3, P.sub.2O.sub.5 and SiO.sub.2,
respectively, and then subjecting the mixture to a hydrothermal
treatment:
Al.sub.2O.sub.3.(1.+-.0.2)P.sub.2O.sub.5.(0.5.+-.0.45)SiO.sub.2.(1.5.+-.0.-
5)Am.(75.+-.25)H.sub.2O (1)
[0013] wherein Am denotes an amine or ammonium salt having 3 to 24
carbon atoms.
[0014] 3) The present invention further relates to a method for
producing methtylamines which comprises allowing methanol to react
with ammonia in the presence of the crystalline
silicoaluminophosphate molecular sieve mentioned in the above
1).
[0015] 4) The present invention further relates to a method for
producing methtylamines which comprises subjecting monomethylamine
to a disproportionation reaction in the presence of the crystalline
silicoaluminophosphate molecular sieve mentioned in the above
1).
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] For selective production of methylamines, especially,
dimethylamine, preference for the molecular sieves is to have an
effective micropore size ranging from 0.3 to 0.6 nm. According to
the IUPAC structural code of zeolites and their analogous
compounds, mention may be made of, for example, 8-membered
ring-structural ABW, AEI, AFX, APC, ATN, ATT, ATV, AWW, CHA, DDR,
EAB, ERI, GIS, JBW, KFI, LEV, LTA, MER, MON, PAU, PHI, RHO, RTE,
RTH, and VNI; 9-membered ring-structural CHI, LOV, RSN, and VSV;
10-membered ring-structural DAC, EPI, FER, LAU, MEL, MFI, MFS, MTT,
NES, TON, and WEI; and 12-membered ring-structural AFS, AFY, ATO,
CAN, GME, MAZ, MEI, MTW, OFF, RON, and VET.
[0017] The present invention uses the crystalline
silicoaluminophosphate molecular sieves (SAPO) having the above
structures. The crystalline silicoaluminophosphate molecular sieves
are products wherein a part of P or Al--P bond is replaced with Si
by an isomorphic replacement, in a crystalline aluminum phosphate
compound (ALPO) having a chemical composition of the following
formula (2) which is represented by oxide mole ratios, excluding
crystalline water and organic bases of structure directing agents
(for example, JP 57-77015 A):
Al.sub.2O.sub.3.(1.0.+-.0.2)P.sub.2O.sub.5 (2).
[0018] Examples are SAPO-17, 18, 26, 31, 33, 34, 35, 37, 40, 41,
42, 44, 47 and 56, and especially preferred are SAPO-17, 18, 34,
35, 44, 47 and 56. Herein, the relationship between the SAPO
numbers and their structures is mentioned, for example, in
Encyclopedia of Inorganic Chemistry, Vol. 8, 4369 (1994). The IUPAC
codes corresponding to SAPO-17, 18, 34, 35, 44, 47 and 56 are ERI,
AEI, CHA, LEV, CHA, CHA, and AFX, respectively. The most preferred
is SAPO-34 of chabazite structure.
[0019] These crystalline silicoaluminophosphate molecular sieves
can be relatively readily manufactured using an aluminum compound,
a phosphorus compound, a silicon compound, an amine or quaternary
ammonium salt as a structure directing agent, and water.
[0020] As methods for manufacturing the crystalline
silicoaluminophosphate molecular sieves, there are known methods as
described in, for example, JP 59-35018 A and a method for
manufacturing catalysts for producing methylamine as described in
JP Application No. 9-197232 in which the sequence of addition of
starting materials or the temperature range is specified. Anyone of
the two methods can be employed. Various products different in
properties can be obtained depending on compositions or pHs of the
starting mixtures, orders of addition of the starting materials,
varieties of the structure directing agents, and/or conditions of
hydrothermal synthesis.
[0021] However, in order to obtain those which have large activity
and selectivity as catalysts for producing methylamine together
with satisfactory catalyst life, it is most important that an
atomic ratio of silicon to aluminum which constitute the
crystalline silicoaluminophosphate molecular sieves falls within
the range of 0.01-0.30. Furthermore, it is preferred that an
average crystal grain size of the crystalline
silicoaluminophosphate molecular sieves measured by a scanning
electron microscope (SEM) is 5 .mu.m or less, that the crystal has
a cubic, rectangular parallelepipedic, spheroidal, hexagonal or
prismatic form, and that both the size and the form of the crystal
are uniform and regular. When the size of the crystal is 5 .mu.m or
less and the form of the crystal is as mentioned above, catalyst
activity and selectivity are further improved and the catalyst life
is further prolonged.
[0022] Atomic ratio of silicon to aluminum should be samll. The
larger the ratio, the shorter the catalyst life. However, as the
ratio is smaller, crystallinity and form are so degraded that
uniform crystals can hardly be obtained. Furthermore, size of
crystals becomes uneven. Therefore, the ratio (Si/Al) is preferably
in the range of 0.01-0.30, especially preferably in the range of
0.05-0.25. In the case of the above composition (Si/Al), atomic
ratio of phosphorus to aluminum is preferably in the range of
0.7-0.9.
[0023] As the aluminum compounds used as the starting materials,
preferred are pseudo-boehmite and aluminum alkoxides having 3 to 24
carbon atoms, such as aluminum isopropoxide. Pseudo-boehmite is
especially preferred because use of it results in the longer
crystal life though the reasons are not certain.
[0024] As the silicon compounds used as the starting materials,
especially preferred are silica, silica sol, orthosilicic acid, and
the like. The aluminum compounds and the silicon compounds usually
contain alkali metals or alkaline earth metals as impurities. Such
impurities usually facilitate an improvement in selectivity in
reaction or initial activity as far as they are in a small amount.
However, if they are contained in an amount exceeding a certain
level, they sometimes have adverse influence on the catalyst life.
Accordingly, the content of impurities should be 200 ppm or
less.
[0025] As the phosphorus compounds used as the starting materials,
especially preferred is orthophosphoric acid, but they are not
limited thereto.
[0026] As the structure directing agents, preferred are amine or
ammonium salts having 3 to 24 carbon atoms. Examples of them are
trimethylamine, triethylamine, triethanolamine, isopropylamine,
dibutylamine, dipentylamine, dihexylamine, piperidine, choline,
morpholine, cyclohexylamine, 2-methylpyridine, 4-methylpyridine,
tripropylamine, quinuclidine, N-methylcyclohexylamine,
N,N-dimethylbenzylamine, N,N-dimethylethanolamine,
N,N-diethylethanolamine, N,N-dimethylpiperazine, tetraethylammonium
hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium
hydroxide.
[0027] Metals and/or metal compounds can be added to the
crystalline silicoaluminophosphate molecular sieves in order to
improve methylamine catalysts in respect to activity, selectivity
and catalyst life. As the metal species to be added, preferred are
Li, Na, Be, Mg, Ca, Sr, Y, Ti, Zr, V, Nb, Cr, Mn, Fe, Ru, Co, Rh,
Ir, Ni, Pd, Pt, Cu, Zn, B, Ga, In, Ge, and Sn. Ti, Y and Zr are
especially preferred. That is, preferred are crystalline
silicoaluminophosphate molecular sieves of H-type in which a part
of the H-type is replaced with at least one metal selected from the
species mentioned above. Alternatively, the same molecular sieves
may be used, as long as they contain the metals or oxides of the
metals. Especially preferred are the crystalline
silicoaluminophosphate molecular sieves of H-type in which a part
of the H-type is replaced with at least one metal selected from Ti,
Y and Zr, and the same molecular sieves which contain titanium
oxide, yttrium oxide or zirconium oxide.
[0028] One of manufacturing procedures for the crystalline
silicoaluminophosphate molecular sieves containing the metals
and/or the metal oxides is as follows. An aluminum compound, a
phosphorus compound, a silicon compound, an amine or ammonium salt
and water are mixed with at least one metal and/or a compound of
the metal selected from Li, Na, Be, Mg, Ca, Sr, Y, Ti, Zr, V, Nb,
Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Zn, B, Ga, In, Ge and
Sn so that the molar ratio satisfies the following formula (1). The
aluminum compound, phosphorus compound and silicon compound are
expressed by Al.sub.2O.sub.3, P.sub.2O.sub.5 and SiO.sub.2,
respectively. Then, the mixture is subjected to a hydrothermal
treatment.
Al.sub.2O.sub.3.(1.+-.0.2)P.sub.2O.sub.5.(0.5.+-.0.45)SiO.sub.2.(1.5.+-.0.-
5)Am.(75.+-.25)H.sub.2O (1)
[0029] wherein Am denotes an amine or ammonium salt having 3 to 24
carbon atoms.
[0030] The metal compounds to be added in this case are preferably
in the form of water-soluble salts thereof such as nitrates,
sulfates and hydrochlorides, Alternatively, metal alkoxides may be
used. Furthermore, it is preferred that the metals are contained in
an amount of 0.05-20% by weight in the silicoaluminophosphate.
[0031] The mixtures are subjected the hydrothermal treatment. The
hydrothermal treatment of the starting mixture is carried out in
the same manner regardless of whether addition of metals and/or
metal compounds have been effected. That is, the treatment is
effected until crystalline silicoaluminophosphate is obtained,
preferably in a pressurized container having Teflon lining at a
temperature of 100-250.degree. C. under autogeneous pressure
usually over a period of 1-200 hours. Then, the product thus
obtained is subjected to filtration, decantation or centrifugal
separation in order to separate crystals. In this case, it is
preferred to effect repeated washing until the washing water is
neutral. Thereafter, the product is dried by keeping it usually at
80-150.degree. C. Moreover, the product is calcined in an oxidizing
atmosphere such as air or in an air stream at a temperature of
350-700.degree. C., preferably 500-600.degree. C.
[0032] Alternatively, the addition of the metals and/or metal
compounds to the crystalline silicoaluminophosphate molecular
sieves may be carried out in such a manner that hydrogen in the
crystalline silicoaluminophosphate molecular sieves of H-type is
replaced with the metals of the metal compounds. The other approach
is uniformly mixing the metals or metal oxides with the crystalline
silicoaluminophosphate molecular sieves before shaping. The
procedures for addition of the metals and/or metal oxides to the
crystalline silicoaluminophosphate molecular sieves are not
critical. No matter how the procedure may be, the product catalysts
are in the form where a part of H-type of the catalysts is replaced
with metal elements, or contain the metals or metal oxides.
[0033] The crystalline silicoaluminophosphate molecular sieves of
the present invention can be suitably used, as they are, as
catalysts for a reaction of methanol with ammonia, reaction of
monomethylamine with methanol, and conversion reaction to
dimethylamine according to a disproportionation reaction of
monomethylamine or the like. Moreover, the crystalline
silicoaluminophosphate molecular sieves of the present invention
can be used for the other catalytic reactions. Furthermore, the
present catalyst may be used as admixtures with other suitable
molecular sieves. Suitable other molecular sieves to be admixed
are, for example; aluminosilicates such as chabazite, mordenite,
erionite, ferrierite, epistilbite, clinoptilolite, paulingite,
phillipsite, levynite, zeolite-A, rho, ZK-5, FU-1, and ZSM-5.
Furthermore, clay minerals such as kaolinite, halloysite, nacrite,
montmorillonite, and illite may be optionally selected and added to
the crystalline silicoaluminophosphate molecular sieves as
binders.
[0034] When catalysts comprising the crystalline
silicoaluminophosphate molecular sieves of the present invention
are used for production of methylamines through a reaction of
methanol with ammonia, production of methylamines through a
reaction of methanol with monomethylamine, or production of
methylamines through disproportionation reaction of
monomethylamine, the reactions are conducted, preferably, in a
flowing system on a gaseous fixed bed or fluidized bed, or in a
system of supplying nitrogen or hydrogen during the flowing.
[0035] Reaction temperature in the production of methylamines or in
the disproportionation reaction of monomethylamine is preferably
200-400.degree. C., especially preferably 250-350.degree. C.
Reaction pressure is not critical. The reaction can be conducted
under reduced pressure or under pressure, but preferably is
conducted under pressure of 0.1-10 MPa. Naturally, the embodiments
of the present invention are not limited to only the above
descriptions.
EXAMPLES
[0036] The present invention will more fully be explained
referreing to the following examples and comparative examples. In
these examples and comparative examples, reactions were conducted
in a flowing reaction apparatus provided with material tanks,
material feeding pumps, inert gas charging devices, reaction tubes
(inner diameter of 13 .O slashed., length of 300 mm, made of SUS
316L), sampling tanks, back pressure valves, etc. After 4 hours
from the reaction reaching a steady state, the product sample was
taken over 1 hour, and analyzed by a gas chromatography to obtain
the composition distribution.
Catalyst Preparation Example 1
[0037] Zirconia-modified SAPO-34:
[0038] A mixture of 35% tetraethylammonium hydroxide (75.7 g) and
pure water (42.3 g) was cooled to 5.degree. C., and thereto was
added aluminum isopropoxide (40.9 g) over a period of 3 minutes,
followed by subjecting the mixture to high-speed stirring for 15
minutes. Then, thereto were added silica sol (9 g) and zirconia
(1.2 g), and the mixture was subjected to high-speed stirring for 5
minutes until it became homogeneous. Furthermore, 85% phosphoric
acid (23.1 g) was added, and the mixture was similarly stirred for
5 minutes, followed by milling for 1 hour. The resulting mixture
was heated at 200.degree. C. for 4 hours in an autoclave. The
product was subjected to centrifugal separation and washing with
water repeatedly 4 times, and then dried overnight at 110.degree.
C. Furthermore, the product was calcined at 600.degree. C. for 4
hours in the air to obtain white crystal powder (22 g). XRD
analysis of this powder gave a diffraction pattern corresponding to
that of SAPO-34. The XRD pattern was sharp and showed a high
crystallinity. The powder was observed by a scanning electron
microscope to find that the crystal had a cubic form of about 1
.mu.m and was highly uniform in both the size and the shape.
Moreover, the powder was subjected to ICP analysis to find that the
atomic ratio of silicon to aluminum was 0.20. This crystal was
compression molded and then pulverized to obtain catalyst 1
comprising uniform particles of 1-2 mm.
Catalyst Preparation Example 2
[0039] SAPO-34:
[0040] A crystal of SAPO-34 which was high in crystallinity and in
cubic form having a particle size of about 1 .mu.m and having
uniform size and shape was obtained in the same manner as in
Catalyst Preparation Example 1, except that zirconia powder was not
added. The atomic ratio of silicon to aluminum was 0.21. This
crystal was compression molded and then pulverized to obtain
catalyst 2 comprising uniform particles of 1-2 mm.
Catalyst Preparation Example 3
[0041] SAPO-34:
[0042] A mixture of 85% phosphoric acid (23.1 g) and pure water
(75.3 g) was cooled to 5.degree. C., and thereto was added
diethanolamine as a structure directing agent (31.6 g) over a
period of 10 minutes, followed by stirring for 2 hours. Then,
thereto was added silica sol (12 g), and the mixture was subjected
to high-speed stirring for 5 minutes until it became homogeneous.
Furthermore, pseudo-boehmite (CATAPAL B manufactured by Condea Co.,
Ltd.) (14.4 g) was added as an aluminum source, followed by
stirring for 2 hours. This mixture was heated at 200.degree. C. for
60 hours in an autoclave. The product was subjected to centrifugal
separation and washing with water, and then dried overnight at
110.degree. C. Furthermore, the product was calcined at 600.degree.
C. for 4 hours in the air to obtain white crystalline powder (20
g). This crystal was SAPO-34 which had a cubic form of about 1
.mu.m in particle size and was highly uniform in both the size and
the shape. Moreover, the powder was subjected to ICP analysis to
find that the atomic ratio of silicon to aluminum was 0.20. The
resulting SAPO-34 was subjected to the same treatment as in
Catalyst Preparation Example 1 to obtain catalyst 3.
Catalyst Preparation Example 4
[0043] SAPO-34:
[0044] SAPO-34 which had an atomic ratio of silicon to aluminum of
0.10 and was in cubic form having a particle size of about 1 .mu.m
and uniform in both the size and the shape was obtained in the same
manner as in Catalyst Preparation Example 3, except that an amount
of the silica sol was 6 g. The resulting SAPO-34 was subjected to
the same treatment as in Catalyst Preparation Example 1 to obtain
catalyst 4.
Catalyst Preparation Example 5
[0045] SAPO-34:
[0046] SAPO-34 which had an atomic ratio of silicon to aluminum of
0.15 and was in cubic form having a particle size of about 1 .mu.m
and uniform in both the size and the shape was obtained in the same
manner as in Catalyst Preparation Example 3, except that an amount
of the silica sol was 9 g. The resulting SAPO-34 was subjected to
the same treatment as in Catalyst Preparation Example 1 to obtain
catalyst 5.
Catalyst Preparation Example 6
[0047] SAPO-34:
[0048] SAPO-34 crystal was obtained in the same manner as in
Catalyst Preparation Example 1, except that 35%-tetraethylammonium
hydroxide was added after aluminum isopropoxide and phosphoric acid
were added. The resulting crystal was in platy form having a
particle size of about 1 .mu.m. This was subjected to the same
treatment and molding as in Catalyst Preparation Example 1 to
obtain catalyst 6.
Catalyst Preparation Example 7
[0049] SAPO-5:
[0050] Catalyst 7 comprising SAPO-5 which was in cubic form having
a particle size of 1 .mu.m or less and uniform in both the size and
the shape and having an atomic ratio of silicon to aluminum of 0.15
was obtained in the same manner as in Catalyst Preparation Example
3, except that an amount of diethanolamine was 41.2 g.
Catalyst Preparation Example 8
[0051] SAPO-44:
[0052] Catalyst 8 comprising SAPO-44 of chabazite structure was
obtained in the same manner as in Catalyst Preparation Example 2,
except that cyclohexylamine was used in place of the
tetraethylammonium hydroxide as the structure directing agent. This
catalyst was in cubic form and had a particle size of 20-100
.mu.m.
Catalyst Preparation Example 9
[0053] SAPO-47:
[0054] Catalyst 9 comprising SAPO-47 of chabazite structure was
obtained in the same manner as in Catalyst Preparation Example 2,
except that methylbutylamine was used in place of the
tetraethylammonium hydroxide as the structure directing agent. This
catalyst was in cubic form and had a particle size of 40-100
.mu.m.
Comparative Catalyst Preparation Example 1
[0055] SAPO-34:
[0056] Catalyst 10 comprising SAPO-34 which had an atomic ratio of
silicon to aluminum of 0.35 was obtained in the same manner as in
Catalyst Preparation Example 3, except that an amount of silica sol
was 24.0 g.
Comparative Catalyst Preparation Example 2
[0057] SAPO-34:
[0058] Catalyst 11 comprising SAPO-34 which had an atomic ratio of
silicon to aluminum of 0.004 was obtained in the same manner as in
Catalyst Preparation Example 3, except that an amount of silica sol
was 1.0 g.
Example 1
[0059] To a reaction tube filled with the catalyst 1 (4.5 g, 10 ml)
was fed a mixture of methanol and ammonia (weight ratio, 1:1) at a
rate of 15 g/h and a gas hourly space velocity (GHSV) of 1500
h.sup.-1 to effect a reaction under a pressure of 2 MPa and a
temperature of 330.degree. C. The results of the initial reaction
were shown below.
1 Methanol conversion ratio: 98.8% Selectivity: Monomethylamine 33
wt % Dimethylamine 63 wt % Trimethylamine 4 wt %
[0060] After lapse of 150 hours, conversion ratio of methanol was
92.0% and no change was seen in amine selectivity. An accelerated
life test was conducted with a GHSV of 2500 h.sup.-1 using the same
catalyst as above. As a result, the conversion ratio of methanol
after lapse of 150 hours was 92.0%, and this test condition
corresponded to 10 times accelerated life test as compared to that
of the GHSV of 1500 h.sup.-1.
Example 2
[0061] The same accelerated life test as in Example 1 was conducted
using the catalyst 2 at a GHSV of 2500 h.sup.-1338 . The initial
methanol conversion ratio was 98.2%, and the conversion ratio after
lapse of 150 hours was 89.0%.
Example 3
The same accelerated life test as in Example 1 was conducted using
the catalyst 3 at a GHSV of 2500 h.sup.-1. The methanol conversion
ratio after lapse of 150 hours was 91.8%.
Example 4
[0062] The same accelerated life test as in Example 1 was conducted
using the catalyst 4 at a GHSV of 2500 h.sup.-1. The methanol
conversion ratio after lapse of 150 hours was 93.2%.
Example 5
[0063] The same accelerated life test as in Example 1 was conducted
using the catalyst 5 at a GHSV of 2500 h.sup.-1. The methanol
conversion ratio after lapse of 150 hours was 92.4%.
Example 6
[0064] The same accelerated life test as in Example 1 was conducted
using the catalyst 6 at a GHSV of 2500 h.sup.-1. The methanol
conversion ratio after lapse of 150 hours was 79.5%.
Example 7
[0065] The same accelerated life test as in Example 1 was conducted
using the catalyst 7 at a GHSV of 2500 h.sup.-1. The methanol
conversion ratio after lapse of 150 hours was 77.5%.
Example 8
[0066] The same accelerated life test as in Example 1 was conducted
using the catalyst 8 at a GHSV of 2500 h.sup.-1. The methanol
conversion ratio after lapse of 150 hours was 69.5%.
Example 9
[0067] The same accelerated life test as in Example 1 was conducted
using the catalyst 9 at a GHSV of 2500 h.sup.-1. The methanol
conversion ratio after lapse of 150 hours was 72.0%.
Example 10
[0068] A dispersion of 5 wt % of stabilized zirconia in water was
added to the catalyst 3 before subjected to molding. The mixture
was well stirred until it became homogeneous, followed by drying
overnight at 110.degree. C. and then calcining at 600.degree. C.
for 4 hours to obtain a catalyst. The resulting catalyst was
subjected to the same life test as in Example 1. The methanol
conversion ratio after lapse of 150 hours was 94.5%.
Example 11
[0069] A dispersion of 5 wt % of chromium oxide powder in water was
added to the catalyst 3 before subjected to molding. The mixture
was well stirred until it became homogeneous, followed by drying
overnight at 110.degree. C. and then calcining at 600.degree. C.
for 4 hours to obtain a catalyst. The resulting catalyst was
subjected to the same life test as in Example 1. The methanol
conversion ratio after lapse of 150 hours was 92.6%.
Example 12
[0070] A dispersion of 5 wt % of tin oxide powder in water was
added to the catalyst 3 before subjected to molding. The mixture
was well stirred until it became homogeneous, followed by drying
overnight at 110.degree. C. and then calcining at 600.degree. C.
for 4 hours to obtain a catalyst. The resulting catalyst was
subjected to the same life test as in Example 1. The methanol
conversion ratio after lapse of 150 hours was 92.0%.
Example 13
[0071] A dispersion of 5 wt % of yttria oxide powder in water was
added to the catalyst 3 before subjected to molding. The mixture
was well stirred until it became homogeneous, followed by drying
overnight at 110.degree. C. and then calcining at 600.degree. C.
for 4 hours to obtain a catalyst. The resulting catalyst was
subjected to the same life test as in Example 1. The methanol
conversion ratio after lapse of 150 hours was 92.0%.
Example 14
[0072] A dispersion of 5 wt % of indium oxide powder in water was
added to the catalyst 3 before subjected to molding. The mixture
was well stirred until it became homogeneous, followed by drying
overnight at 110.degree. C. and then calcining at 600.degree. C.
for 4 hours to obtain a catalyst. The resulting catalyst was
subjected to the same life test as in Example 1. The methanol
conversion ratio after lapse of 150 hours was 92.0%.
Comparative Example 1
[0073] The same accelerated life test as in Example 1 was conducted
using the catalyst 10 at a GHSV of 2500 h.sup.-1. The methanol
conversion ratio after lapse of 150 hours was 68.5%.
Comparative Example 2
[0074] The same accelerated catalyst life test as in Example 1 was
conducted using the catalyst 11 at a GHSV of 2500 h.sup.-1. The
methanol conversion ratio after lapse of 150 hours was 69.0%.
Example 15
[0075] To a reaction tube filled with the catalyst 1 (2.0 g, 4.0
ml) was fed monomethylamine at a GHSV of 2500 h.sup.-1 under a
reaction pressure of 2 MPa and a temperature of 350.degree. C. to
conduct an accelerated life test. The results of disproportionation
reaction to produce ammonia and dimethylamine from monomethylamine
were shown below.
2 Monomethylamine conversion ratio: 83.1% Selectivity:
Dimethylamine 97 wt % Trimethylamine 3 wt %
[0076] The conversion ratio of monomethylamine after lapse of 150
hours was 82.8%.
Example 16
[0077] The accelerated life test in disproportionation of
monomethylamine was conducted in the same manner as in Example 15
using the catalyst 2 at a GHSV of 2500 h.sup.-1. The
monomethylamine conversion ratio after lapse of 150 hours was
82.2%.
[0078] The results of the reactions of methanol with ammonia and
the disproportionation reactions of monomethylamine in Examples of
the present invention and Comparative Examples are shown in Table
1.
3 TABLE 1 Conversion Particle ratios at life test size Preparation
Initial 150 h Catalysts Si/Al .mu.m Shapes methods* % %
(Accelerated life test) Ex. 1 1 (ZrSAPO-34) 0.20 1 cubic A 98.8
92.0 Ex. 2 2 (SAPO-34) 0.21 1 cubic A 98.2 89.0 Ex. 3 3 (SAPO-34)
0.20 1 cubic B 98.6 91.8 Ex. 4 4 (SAPO-34) 0.10 1 cubic B 97.8 93.2
EX. 5 5 (SAPO-34) 0.15 1 cubic B 98.2 92.4 Ex. 6 6 (SAPO-34) 0.16 1
platy A 94.3 79.5 Ex. 7 7 (SAPO-5) 0.15 1 cubic A 82.4 77.5 Ex. 8 8
(SAPO-44) 0.30 20-100 cubic B 79.2 69.5 Ex. 9 9 (SAPO-47) 0.29
40-100 cubic B 82.0 72.0 Ex. 10 3a (Zr + 3) 0.20 1 cubic B 98.8
94.5 Ex. 11 3b (Cr + 3) 0.20 1 cubic B 98.8 92.6 Ex. 12 3c (Sn + 3)
0.20 1 cubic B 98.8 92.0 Ex. 13 3d (Y + 3) 0.20 1 cubic B 98.8 92.0
Ex. 14 3e (In + 3) 0.20 1 cubic B 98.8 92.0 Comp. 10 (SAPO-34) 0.35
1 cubic B 92.2 68.5 Ex. 1 Comp. 11 (SAPO-34) 0.004 1 cubic B 90.6
69.0 Ex. 2 (Disporportionation reaction) Ex. 15 1 (ZrSAPO-34) 0.20
1 cubic A 83.1 82.8 Ex. 16 2 (SAPO-34) 0.20 1 cubic A 82.8 82.2
Notes 1. Reaction conditions: Temperature 330.degree. C.; pressure
2 MPa; GHSV 2500 h.sup.-1 2. Preparation methods*: A (aluminum
source: aluminum isopropoxide) B (aluminum source: aluminum
pseudo-boehmite)
[0079] The results of Examples and Comparative Examples show that
the catalysts of the present invention produce only a small amount
of trimethylamine which has little demand in the production of
methylamines through the reaction of methanol with ammonia or the
production of dimethylamine through a disproportionation reaction
of methylamines. The present catalysts have a prolonged life than
conventional catalysts. Therefore, the catalysts and the
manufacturing methods thereof provided by the present invention are
useful for selective production of dimethylamine, and the present
invention has very large industrial values.
* * * * *