U.S. patent application number 10/938604 was filed with the patent office on 2005-03-10 for catalyst for epoxidation reactions.
This patent application is currently assigned to BASF Aktiengesellschaft. Invention is credited to Bassler, Peter, Gobbel, Hans-Georg, Krug, Georg, Muller, Ulrich, Rudolf, Peter, Teles, Joaquim Henrique.
Application Number | 20050054865 10/938604 |
Document ID | / |
Family ID | 31991705 |
Filed Date | 2005-03-10 |
United States Patent
Application |
20050054865 |
Kind Code |
A1 |
Muller, Ulrich ; et
al. |
March 10, 2005 |
Catalyst for epoxidation reactions
Abstract
The present invention relates to the manufacture of solid
materials or shaped bodies containing at least one zeolite and
being at least partly crystalline. Furthermore, the present
invention relates to the solid materials or shaped bodies as such
and to the use of these materials for reactions of compounds having
at least one C--C double bond with at least one hydroperoxide.
Specifically, the present invention relates to a process for the
manufacture of a solid material containing at least one zeolite and
being at least partly crystalline, wherein the synthesis of the
said solid material involves at least one partial step of
contacting at least one transition metal oxide source with at least
one epoxide or hydrolysate thereof prior to or during the at least
partial crystallization of said solid material.
Inventors: |
Muller, Ulrich;
(Neustadt/Mussbach, DE) ; Krug, Georg;
(Moerlenbach, DE) ; Bassler, Peter; (Viernheim,
DE) ; Gobbel, Hans-Georg; (Mannheim, DE) ;
Rudolf, Peter; (Ladenburg, DE) ; Teles, Joaquim
Henrique; (Otterstedt, DE) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
BASF Aktiengesellschaft
Ludwigshafen
DE
|
Family ID: |
31991705 |
Appl. No.: |
10/938604 |
Filed: |
September 13, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10938604 |
Sep 13, 2004 |
|
|
|
10243669 |
Sep 16, 2002 |
|
|
|
Current U.S.
Class: |
549/533 ;
502/60 |
Current CPC
Class: |
B01J 29/89 20130101;
C07D 301/12 20130101 |
Class at
Publication: |
549/533 ;
502/060 |
International
Class: |
C07D 301/06; B01J
029/04; B01J 029/87 |
Claims
1-19. (Canceled).
20. A catalytic material for epoxidation reactions containing at
least one zeolite and being at least partially crystalline,
obtainable by a process comprising the steps (I) at least partial
crystallization of at least one solid material containing at least
one zeolite out of a synthesis mixture, said mixture comprising at
least a silicon source, a transition metal oxide source and a
mineralizing and/or structure forming agent, resulting in a mixture
(I) containing at least said solid material and a mother liquor,
step (I) further comprising adding an epoxide or hydrolysate
thereof to the transition metal oxide source; (II) separating
and/or concentrating of the solid material from mixture (I),
wherein step (II) additionally includes drying of the solid
material; (C) calcining of the solid material at temperatures
higher than 400.degree. C.
21. The catalytic material of claim 20, wherein the silicon source
comprises at least one silicon oxide, the transition metal oxide
source comprises at least one titanate, and the mineralizing and/or
structure forming agent comprises at least one tetraalkylammonium
hydroxide.
22. The catalytic material of claim 20, wherein the silicon source
comprises at least tetraethoxy silicate, the transition metal oxide
source comprises at least tetrabutylorthotitanate, the mineralizing
and/or structure forming agent comprises at least
tetrapropylammonium hydroxide, and the epoxide or hydrolysate
thereof comprises at least propylene oxide or propylene glycol.
23. The catalytic material of claim 20, wherein the zeolite
contains Ti.
24. The catalytic material of claim 20, wherein the zeolite is a
titanium silicalite.
25. The catalytic material of claim 20, wherein in step (II), the
solid material is separated from the mother liquor by filtration,
ultrafiltration or diafiltration.
26. The catalytic material of claim 20, wherein in step (II), the
solid material is separated from the mother liquor by spray drying
or spray granulation.
27. The catalytic material of claim 20, said process further
comprising (S) shaping of the solid material to produce a shaped
body.
28. The catalytic material of claim 27, said process further
comprising drying the shaped body at a temperature of from about
30.degree. C. to about 140.degree. C. for a time from 1 to 20 h and
subsequently calcining the dried shaped body at a temperature of
from about 400.degree. C. to about 800.degree. C. for a time from
about 3 h to about 10 h.
29. The catalytic material of claim 28, said process further
comprising (W) bringing the dried and calcined shaped body in
contact with a composition containing water.
30. A catalytic material for epoxidation reactions containing at
least one zeolite and being at least partially crystalline,
obtainable by a process comprising a step (I), which step comprises
at least partial crystallization of at least one solid material
containing at least one zeolite out of a synthesis mixture, wherein
said process comprises contacting at least one transition metal
oxide source with at least one epoxide or hydrolysate thereof prior
to or during the at least partial crystallization, wherein step (I)
comprises (Ia) mixing of at least one hydrolyzable silicon source
with a mineralizing and/or structuring agent and water; (Ib) mixing
of at least one transition metal oxide source with an epoxide or a
hydrolysate thereof; (Ic) mixing of the mixtures from (Ia) and (Ib)
so that at least a part of the hydrolyzable compounds hydrolyzes;
(Id) distilling at least parts of the alcohol that has been formed
as a result of the at least partial hydrolysation of at least part
of the hydrolyzable compounds; (Ie) adding water to the bottom of
(Id); (If) reacting of the synthesis mixture resulting from (Ie) at
a temperature elevated with respect to room temperature to obtain a
mixture (I) of the solid material in its mother liquor, said
process further comprising (II) separating and/or concentrating of
the solid material in mixture (I), wherein (II) additionally
includes drying of the solid material; (C) calcining of the solid
material at temperatures higher than 400.degree. C.
31. The catalytic material of claim 30, wherein the hydrolyzable
silicon source comprises at least one silicon oxide, the
mineralizing and/or structuring agent comprises at least one
tetraalkylammonium hydroxide, and the transition metal oxide source
comprises at least one titanate.
32. The catalytic material of claim 30, wherein the epoxide is
propylene oxide and the hydrolysate of the epoxide is propylene
glycol.
33. The catalytic material of claim 32, wherein the hydrolyzable
silicon source comprises at least tetraethoxy silicate, the
mineralizing and/or structuring agent comprises at least
tetrapropylammonium hydroxide, the transition metal oxide source
comprises at least tetrabutylorthotitanate.
34. The catalytic material of claim 33, wherein in (Ib), the
transition metal oxide source is mixed with propylene glycol.
35. The catalytic material of claim 30, wherein the at least one
zeolite contains Ti and belongs to at least one of the following
structure classes consisting of the group of MFI, MEL, MWW, BEA and
any mixed structures thereof.
36. The catalytic material of claim 30, wherein the at least one
zeolite is a titanium silicalite.
37. The catalytic material of claim 30, wherein in step (II), the
solid material is separated from the mother liquor.
38. The catalytic material of claim 37, wherein in step (II), the
solid material is separated from the mother liquor by filtration,
ultrafiltration or diafiltration.
39. The catalytic material of claim 37, wherein in step (II), the
solid material is separated from the mother liquor by spray drying
or spray granulation.
40. The catalytic material of claim 30, said process further
comprising (S) shaping of the solid material to produce a shaped
body.
41. The catalytic material of claim 40, wherein (S) comprises
adding a binding material to the solid material.
42. The catalytic material of claim 41, wherein the binding
material is selected from the group consisting of hydrated silica
gel, silicic acid, tetraalkoxy silicates, tetraalkoxy titanates,
tetraalkoxy zirconates and mixtures of two or thereof.
43. The catalytic material of claim 41, wherein the binding
material is selected from the group consisting of tetramethoxy
silicate, tetraethoxy silicate and silica sols.
44. The catalytic material of claim 41, wherein (S) comprises
milling the solid material and mixing the milled solid material
with silica sol, a dispersion of polystyrene, cellulose,
polyethylene oxide and water, kneading the resulting mixture and
molding the kneaded mixture.
45. The catalytic material of claim 44, wherein molding is
extrusion molding.
46. The catalytic material of claim 45, the extrudates obtained
having a diameter ranging from about 2 to about 5 mm.
47. The catalytic material of claim 40, said process further
comprising drying the shaped body at a temperature of from about
30.degree. C. to about 140.degree. C. for a time from 1 to 20 h and
subsequently calcining the dried shaped body at a temperature of
from about 400.degree. C. to about 800.degree. C. for a time from
about 3 h to about 10 h.
48. The catalytic material of claim 47, said process further
comprising (W) bringing the dried and calcined shaped body in
contact with a composition containing water.
49. The catalytic material of claim 48, wherein the composition
containing water is water in its liquid phase or water steam.
50. A shaped body for the use as catalyst for reactions of
compounds having at least one C--C double bond with at least one
hydroperoxide, said shaped body comprising at least one solid
material containing at least one zeolite, said zeolite containing
Ti and being selected from the group consisting of MFl, MEL, MWW,
BEA and any mixed structures thereof, and said solid material being
at least partially crystalline, wherein the shaped body is
obtainable by a process comprising a step (I), which step comprises
at least partial crystallization of the at least one solid material
containing at least one zeolite out of a synthesis mixture, wherein
said process comprises contacting at least one transition metal
oxide source with at least one epoxide or hydrolysate thereof prior
to or during the at least partial crystallization, wherein step (I)
comprises (Ia) mixing of at least one hydrolyzable silicon source
with a mineralizing and/or structuring agent and water; (Ib) mixing
of at least one transition metal oxide source with an epoxide or a
hydrolysate thereof; (Ic) mixing of the mixtures from (Ia) and (Ib)
so that at least a part of the hydrolyzable compounds hydrolyzes;
(Id) distilling at least parts of the alcohol that has been formed
as a result of the at least partial hydrolysation of at least part
of the hydrolyzable compounds; (Ie) adding water to the bottom of
(Id); (If) reacting of the synthesis mixture resulting from (Ie) at
a temperature elevated with respect to room temperature to obtain a
mixture (I) of the solid material in its mother liquor, said
process further comprising (II) separating and/or concentrating of
the solid material in mixture (I), wherein (II) additionally
includes drying of the solid material; (C) calcining of the solid
material at temperatures higher than 400.degree. C.; (S) shaping of
the solid material to produce a shaped body.
51. The shaped body of claim 50, wherein the hydrolyzable silicon
source comprises at least one silicon oxide, the mineralizing
and/or structuring agent comprises at least one tetraalkylammonium
hydroxide, and the transition metal oxide source comprises at least
one titanate.
52. The shaped body of claim 50, wherein the hydrolyzable silicon
source comprises at least tetraethoxy silicate, the mineralizing
and/or structuring agent comprises at least tetrapropylammonium
hydroxide, the transition metal oxide source comprises at least
tetrabutylorthotitanate, wherein the epoxide is propylene oxide and
the hydrolysate of the epoxide is propylene glycol.
53. The shaped body of claim 50, wherein the at least one zeolite
is a titanium silicalite.
54. The shaped body of claim 50, wherein (S) comprises adding a
binding material to the solid material, the binding material being
selected from the group consisting of tetramethoxy silicate,
tetraethoxy silicate and silica sols.
55. The shaped body of claim 50, wherein (S) comprises milling the
solid material and mixing the milled solid material with silica
sol, a dispersion of polystyrene, cellulose, polyethylene oxide and
water, kneading the resulting mixture and molding the kneaded
mixture by extrusion molding, wherein extrudates are obtained
having a diameter ranging from about 2 to about 5 mm.
56. The shaped body of claim 50, said process further comprising
drying the shaped body at a temperature of from about 30.degree. C.
to about 140.degree. C. for a time from 1 to 20 h and subsequently
calcining the dried shaped body at a temperature of from about
400.degree. C. to about 800.degree. C. for a time from about 3 h to
about 10 h.
57. The shaped body of claim 56, said process further comprising
(W) bringing the dried and calcined shaped body in contact with a
composition containing water.
58. The shaped body of claim 57, wherein the composition containing
water is water in its liquid phase or water steam.
59. The shaped body of claim 50, wherein in step (II), the solid
material is separated from the mother liquor by filtration,
ultrafiltration or diafiltration.
60. The shaped body of claim 50, wherein in step (II), the solid
material is separated from the mother liquor by spray drying or
spray granulation.
61. A shaped body for the use as catalyst for the epoxidation of
propene with hydrogen peroxide, said shaped body comprising at
least one solid material containing a titanium silicalite zeolite
and being at least partially crystalline, wherein the shaped body
is obtainable by a process comprising a step (I), which step
comprises at least partial crystallization of the at least one
solid material containing the zeolite out of a synthesis mixture,
wherein said process comprises contacting tetrabutylorthotitanate
with propylene oxide or propylene glycol prior to or during the at
least partial crystallization, wherein step (I) comprises (Ia)
mixing of tetraethoxy silicate with tetrapropylammonium hydroxide
and water; (Ib) mixing of tetrabutylorthotitanate with propylene
oxide or propylene glycol; (Ic) mixing of the mixtures from (Ia)
and (Ib) so that at least a part of the hydrolyzable compounds
hydrolyzes; (Id) distilling at least parts of the alcohol that has
been formed as a result of the at least partial hydrolysation of at
least part of the hydrolyzable compounds; (Ie) adding water to the
bottom of (Id); (If) reacting of the synthesis mixture resulting
from (Ie) at a temperature elevated with respect to room
temperature to obtain a mixture (I), said process further
comprising (II) separating of the solid material in mixture (I) by
filtration, ultrafiltration, diafiltration, spray-drying or
spray-granulation, wherein (II) additionally includes drying of the
solid material; (C) calcining of the separated solid material at
temperatures higher than 400.degree. C.; (S) shaping of the solid
material to produce a shaped body comprising milling the solid
material and mixing the milled solid material with silica sol, a
dispersion of polystyrene, cellulose, polyethylene oxide and water,
kneading the resulting mixture and molding the kneaded mixture by
extrusion molding, wherein extrudates are obtained having a
diameter ranging from about 2 to about 5 mm; said process further
comprising drying the extrudates at a temperature of from about
30.degree. C. to about 140.degree. C. for a time from 1 to 20 h and
subsequently calcining the dried shaped body at a temperature of
from about 400.degree. C. to about 800.degree. C. for a time from
about 3 h to about 10 h.
62. The shaped body of claim 61, wherein separation in (II) is
filtration, ultrafiltration or diafiltration.
63. The shaped. body of claim 61, said process further comprising
(W) bringing the dried and calcined extrudates in contact with a
composition containing water, wherein the composition containing
water is water in its liquid phase or water steam.
Description
[0001] The present invention relates to the manufacture of solid
materials or shaped bodies containing at least one zeolite and
being at least partly crystalline. Furthermore, the present
invention relates to the solid materials or shaped bodies as such
and to the use of these materials for reactions of compounds having
at least one C--C double bond with at least one hydroperoxide.
Specifically, the present invention relates to a process for the
manufacture of a solid material containing at least one zeolite and
being at least partly crystalline, wherein the synthesis of the
said solid material involves at least one partial step of
contacting at least one transition metal oxide source with at least
one epoxide or hydrolysate thereof prior to or during the at least
partial crystallization of said solid material.
[0002] The synthesis of solid materials containing at least Si and
Ti, in particular of titanium zeolithes used for applications in
catalysis, is of particular commercial importance and has resulted
in a large body of prior art. By way of example, U.S. Pat. No.
4,666,692 and U.S. Pat. No 4,410,501 are cited in the general
context of the manufacture of titanium silicalites.
[0003] An integrated process for producing solid materials
containing Si and Ti and shaped bodies produced therefrom is
described, e.g. in WO 98/55229.
[0004] The scientific publication "Studies of the synthesis of
titanium silicalite, TS-1" from A. Thangaraj et al. [Zeolites 12
(1992) 943 ff] relates to a procedure to obtain TS-1, wherein the
precipitation of titanium oxide during the hydrolysis of the
alkoxides in the synthesis mixture is minimized or avoided by
adding, in a step separate step, isopropyl alcohol to the titanium
source. Not only is it found that the amount of metal oxide
precipitation indeed decreases, but also that more Ti is built into
the silicalite framework. However, said publication is silent as to
the use of other compounds to be added to a transition metal oxide
source and is silent as to the effect such treatment has on the
catalyst actually used in a chemical reaction, e.g. an epoxidation
reaction.
[0005] Referring to said scientific publication, U.S. application
2001/0041162 A 1 describes the use of alcohols having a pK.sub.a
value lower than that of water, more specifically the use of
2-ethoxyethanol, in order to avoid precipitation metal oxides such
as anatase, from the synthesis solution. As a result it is found
that indeed the molar fraction of precipitated Ti in anatase form
is significantly reduced. However, no significant effect on
important performance characteristics of the catalyst actually used
for epoxidation reactions were identified, in particular on epoxide
selectivity.
[0006] The object of the present invention was to provide a
catalyst, and a process for the manufacture thereof, that results
in improved performance characteristics of catalysts based on
zeolite materials, in particular with respect to selectivity and
activity, over the prior art.
[0007] Surprisingly, it has been found that by adding the epoxide
that is the product of the desired catalyzed epoxidation reaction,
or a hydrolysate thereof, to the transition metal oxide source, the
performance characteristics of the catalyst obtained from the
synthesis mixture comprising the transition metals oxide source so
treated, is improved over a corresponding catalyst that had not
been subjected to the inventive step of adding an epoxide or
hydrolysate thereof to the transition metal oxide source.
[0008] The catalytic material (solid material or shaped body)
obtainable by the inventive process of adding an epoxide or
hydrolysate thereof can be used for any catalytic reaction in which
it improves at least one reaction parameter or catalyst performance
characteristic, such as selectivity, yield, activity, over the
respective values obtained using catalytic material that has not
been subjected to the inventive treatment of adding an epoxide or
hydrolysate thereof to the transition metal oxide source.
[0009] Preferably, the catalytic material obtainable by the
inventive process is used in reactions of compounds containing at
least one C--C-double bounds with at least one hydroperoxide, i.e.
in epoxidation reactions.
[0010] In the following, a glossary of the most important
expressions used in the framework of the present invention are
defined.
[0011] A "synthesis mixture" as used in the context of the present
invention pertains to any mixture which yields, by means of
crystallization, a mixture containing a solid material that is at
least partially crystalline and a fluid material. Preferably, the
synthesis mixture contains at least a Si source (Si precursor), a
transition metal oxide source (transition metal precursor) and a
mineralizing and/or structure forming agent. In particular,
reference is made to all synthesis mixtures known to the expert in
the field of zeolite preparation, particularly the hydrothermal
treatment of gels. The synthesis mixture may be a sol, gel,
solution, or a suspension. The synthesis mixture may be obtained by
mixing two separate solutions.
[0012] "Zeolites" as used in the context of the present invention
are crystalline alumosilicates with well-ordered channel or cage
structures containing micropores. The expression "micronore" as
used in the context of the present invention corresponds to the
definition given in "Pure Applied Chemistry", Vol. 45, p. 71 ff.,
in particular p. 79 (1976). According to this definition,
micropores are pores with a pore diameter of less than 2 nm. The
network of these zeolites is made of SiO.sub.4 and
AlO.sub.4-tetrabedra that are bridged via shared oxygen bonds. An
overview of the known structures can be found in, example given, W.
M. Meier and D. H. Olson in "Atlas of Zeolite Structure Types",
Elsevier, 4.sup.th Ed., London 1996. In addition to micropores,
solid materials or shaped bodies according to the invention may
contain mesopores or macropores as well.
[0013] "Solid materials" as obtained, for example, after the
crystallization of the synthesis mixture, are to be understood in
the context of the present invention as any known material which
displays at least the following properties: (i) it contains at
least one zeolite material and (ii) is different from the synthesis
mixture described before in the sense that a separation of said
solid material from its mother liquor is possible and/or
concentrating of the solid material by, e.g., ultra-filtration is
possible. Typically, the solid material prevails as particles
suspended in the mother liquor.
[0014] A "mother liquor" in the context of the present invention is
any liquid phase that may contain a unlimited number of substances
dissolved therein, however in itself is not a solid material. In
particular, the mother liquor may contain adjuvants dissolved
therein. In the sense of the present invention, a mother liquor can
only occur after step (I) of the integrated process as described
above. Typically, a mother liquor is the liquid phase in which the
solid material is suspended in the form of particles. Said mixture
(I) is then subjected to step (II) of separating and/or
concentrating of the solid material in mixture (I).
[0015] The term "epoxide" as used in the context of the present
invention, refers to any compound with at least two adjacent carbon
atoms, wherein at least those two carbon atoms are, at least
partly, chemically bound to one mutual oxygen atom. By way of
example, propylene oxide is mentioned. A "hydrolysate" of an
epoxide is the product of the reaction of the epoxide with any
compound leading to hydrolysis, e.g. water. By way of example,
propylene glycol is mentioned as the hydrolysate of the above
mentioned propylene oxide.
[0016] Step (II) of the present invention relates to concentrating
and/or separating of the solid material in the mother liquor and/or
from the mother liquor, wherein the mixture (I) containing the
solid material is obtained from step (I). The term "concentrating
and/or separating" is to be understood in the context of the
present invention as any step that at least results in that at the
end of step (II), the solid material content in the mixture is
increased and/or the solid material is separated partly or entirely
from the mother liquor.
[0017] The complete "separation" of the solid material from the
mixture (the suspension) is explicitly contained in the definition
of "concentrating" as an extreme case. Such methods of separating
and/or concentrating include, but are only limited to, spray-drying
or ultra-filtration and will be described in more detail below. The
terms "filtration", "ultra-filtration", and "spray-drying" as well
as other methods of concentrating and/or separating the solid
material from the mother liquor are described in detail in DE 102
324 06.9, the respective content of which is hereby incorporated by
reference.
[0018] A "shaped body" as used in the context of the present
invention is to be understood to be any three dimensional entity,
which can be obtained by any of the shaping steps (S) mentioned
below. The shaped body is obtained in a typical manner by means of
compacting of the solid material described above. Said solid
material may originate from steps (II) and/or (III), using optional
steps of calcining (C).
[0019] The expressions "granulating" and "agglomerating" as used in
the context of the present invention are to be seen as synonymous
and describe, respectively, any conceivable process that can be
used to increase the diameter of the particles obtained from step
(II). Said increase of the particle diameter can be achieved by
baking the particles together or by growing on the particles layer
by layer. The process of granulating thereby includes but is not
limited to processes taking advantage of the phenomenon of wetting
of the particles by at least one liquid. Furthermore, binding
materials may be added to the mixture in order to enhance or enable
the agglomerating and/or granulating of the particles.
[0020] A "binding material" as used in the context of the present
invention is to be understood to be any material that enables a
physical, chemical, or physical-chemical bond between the
substances constituting the particle. Such binding materials may be
used in the step (S) of shaping or forming the solid materials into
a shaped body as well. Reference is made to the description of
binding materials in that context.
[0021] The inventive treatment of of adding an epoxide or
hydrolysate thereof to the transition metal oxide source is
preferably part of an integrated process, namely an integrated
process producing a mechanically stable solid material or a shaped
body containing at least one zeolite material. Schematically, such
an integrated process can be characterized by the following
steps:
[0022] (I) at least partial crystallization of at least one solid
material containing at least one zeolite out of a synthesis
mixture, resulting in mixture (I) containing at least said solid
material and a mother liquor;
[0023] (II) separating and/or concentrating of the solid material
from mixture (I);
[0024] (W) bringing the solid material from step (II) in contact
with a composition containing water;
[0025] (III) agglomerating or granulating or agglomerating and
granulating of the solid material from step (W);
[0026] wherein steps (W) and (III) are optional. Step (II) may
additionally include the drying and/or washing of the solid
material, possibly also in several iterations.
[0027] Additionally, and/or optionally the following steps may be
part of the integrated process as well:
[0028] (S) shaping of the solid material into shaped bodies
subsequent to steps (W) or (III);
[0029] (C) Calcining of the solid material and/or the shaped body
at temperatures higher than 400.degree. C.;
[0030] wherein the step (C) of calcining may be performed at least
once after at least one of the following steps of the integrated
process: (II), (W), or (III).
[0031] In a preferred embodiment, step (W) is performed after step
(S) of shaping the solid material.
[0032] In the present application, the inventive solid material
containing at least one zeolite material or the shaped body
obtainable therefrom is discussed in the context of applications in
the field of catalysis. This, however, cannot be construed as a
limitation of the use of the solid material and/or the shaped body
to the field of catalysis. The explicit discussion of examples in
the field of catalysis is illustrative only. The inventive material
may be used in other fields as well.
[0033] In the following, the individual steps of the integrated
process for producing a solid material and/or shaped body are
summarized, wherein the solid material and/or the shaped body
contain at least one zeolite material and is/are at least partially
crystalline. Of particular importance is the step (I) containing
the inventive partial step (Ib)
[0034] Step I: (Partial) Crystallization of the Synthesis
Mixture
[0035] According to the present invention, step (I) of the at least
partial crystallization of at least one solid material containing
at least one zeolite out of a synthesis mixture, resulting in
mixture (I) containing at least said solid material and a mother
liquor comprises at least the following partial steps:
[0036] (Ia) mixing of at least one hydrolyzable silicon source with
a mineralizing and/or structuring agent and water;
[0037] (Ib) mixing of at least one transition metal oxide source
with an epoxide or a bydrolysate thereof;
[0038] (Ic) mixing of the mixtures from (Ia) and (Ib) so that at
least a part of the hydrolyzable compounds hydrolyzes;
[0039] (Id) distilling at least parts of the alcohol that has been
formed as a result of the at least partial hydrolysation of at
least part of the hydrolyzable compounds;
[0040] (Ie) adding water to the bottom of (Id);
[0041] (If) reacting of the synthesis mixture resulting from (Ie)
at a temperature elevated with respect to room temperature.
[0042] Preferably, steps (Ia) and (Ib) are performed in separate
containers.
[0043] In a preferred embodiment, the hydrolyzable silicon source
comprises at least one silicon oxide, the mineralizing and/or
structuring agent comprises at least one tetraalkylammoniun
hydroxide, the transition metal oxide source comprises at least one
titanate and the epoxide or hydrolysate thereof comprises at least
the epoxide or the hydrolysate thereof of the reaction for which
the solid material is ultimately used as a catalyst.
[0044] In a further preferred embodiment, the hydrolyzable silicon
source comprises at least tetraethoxy silicate, the mineralizing
and/or structuring agent comprises at least tetrapropylammonium
hydroxide, the transition metal oxide source comprises at least
tetrabutylorthotitanate and the epoxide or the hydrolysate thereof
comprises at least propylene oxide or propylene glycol, with
propylene glycol being particularly preferred.
[0045] As far as the least one zeolite material resulting from said
synthesis step (I) is concerned, no limitations exist. Preferably,
a zeolite containing titanium, zirconium, chromium, niobium, iron,
bor, vanadium is employed. Particularly preferred, a zeolite
containing titanium is employed, wherein zeolites known to the
expert in the field as "titanium silicates" (TS) are particularly
preferred.
[0046] Such zeolites containing titanium, in particular those
displaying a crystalline structure of the MFI-type as well as ways
for producing them are described, for example, in WO 98/55228, WO
98/03394, WO 98/03395, EP-A 0 311 983, or EP-A 405 978. The
respective content of these documents is-hereby incorporated by
reference. In addition to Si and Ti, said zeolite materials may
contain additional elements, such as aluminum zirconium, tin, iron,
cobalt, nickel, gallium, bor, or small amounts of fluorine. It is
preferred that the titanium of the zeolite is partly or completely
replaced by vanadium, zirconium, or niobium, or any mixture of two
or more of these components.
[0047] Zeolites containing titanium and displaying a MFI-structure
are known to yield a characteristic pattern in x-ray diffraction.
Furthermore, these materials display a vibration band in the
infrared (IR) at approximately 960 cm.sup.-1. Therefore, it is
possible to distinguish the zeolites containing titanium from
crystalline or amorphous TiO.sub.2-phases or from alkaline metal
titanates.
[0048] In a further preferred embodiment, the at least one zeolite
material is selected from the following group: zeolites containing
at least one of the following elements: titanium, germanium,
tellurium, vanadium, chromium, niobium, zirconium, particularly
those having a pentasil zeolite structure, in particular the
structural types that can be, via x-ray diffraction, assigned to
the structure types of ABW--, ACO--, AEI--, AEL-, AEN--, AET-,
AFG-, AFI--, AFN--, AFO--, AFR--, AFS--, AFT-, AFX--, AFY--, AHT-,
ANA-, APC--, APD-, AST-, ATN--, ATO--, ATS--, ATT-, ATV--, AWO--,
AWW--, BEA-, BIK--, BOG-, BPH--, BRE-, CAN--, CAS--, CFT-, CGF--,
CGS--, CHA-, CHI--, CLO--, CON--, CZP--, DAC--, DDR--, DFO--, DFT-,
DOH--, DON--, EAB--, EDI--, EMT-, EPI--, ERI--, ESV--, EUO--,
FAU--, FER--, GIS--, GME-, GOO--, HEU--, IFR--, ISV--, ITE-, JBW--,
KFI---LAU--, LEV--, LIO--, LOS--, LOV--, LTA-, LTL-, LTN--, MAZ-,
MEI--, MEL-, MEP--, MER--, MFI--, MFS--, MON--, MOR--, MSO--,
MTF--, MTN--, MTT-, MTW--, MWW--, NAT-, NES--, NON--, OFF--, OSI--,
PAR--, PAU--, PHI--, RHO--, RON--, RSN--, RTE-, RTH--, RUT-, SAO--,
SAT-, SBE-, SBS--, SBT-, SFF--, SGT-, SOD-, STF--, STI--, STT-,
TER--, THO--, TON--, TSC--, VET-, VFI--, VNI--, VSV--, WIE-, WEN--,
YUG-, ZON, as well as mixed structures of at least two or more of
the aforementioned structures. Furthermore, it is conceivable to
use zeolites containing titanium with the structure of ITQ-4,
ITQ-9, SSZ-24, TTM-1, UTD-1, CIT-1 or CIT-5. Further zeolites
containing titanium are such of the structure types ZSM-48 or
ZSM-12.
[0049] Zeolites containing titanium of the structure MFI, MEL or
MFI/MEL mixed structures, as well as MWW, BEA or mixed structures
thereof are preferred in the context of the present invention.
Further preferred in the context of the present invention are these
zeolite catalysts containing titanium that are referred to, in
general, as "TS-1", "IS-2" or "TS-3", as well as zeolites
containing titanium displaying a structure that is isomoirphous to
.beta.-zeolite.
[0050] If necessary, or advantageous, additional compounds may be
added. The reaction or mixing of each partial step of step (I) is
performed in an open container or in a pressure-tight container
(autoclave), optionally at elevated temperatures, over the course
of several hours or days. Thereby, a product that is at least
partly crystalline is obtained.
[0051] As far as the duration of the inventive partial step is
concerned, no limitations exist, so long as the partial step
results in an improved performance of the catalyst over a catalyst
that had not been subjected to that partial step. As a measure for
the increased performance, improved activity, selectivity and/or
yield may be used. Increased mechanical stability or improved
properties that are otherwise relevant for the process of interest
can be used as well. In a preferred embodiment, the inventive
partial step (Ib) consists of mixing the transition metal oxide
source with the epoxide or hydroxide and stirring until the
solution is transparent to the eye.
[0052] Step (II): Separating and/or Concentrating
[0053] In step (II) the solid material is separated from the mother
liquor and/or is concentrated in the mother liquor. Step (II) is
performed with mixture (I) from step (I). Methods of separating
and/or concentrating include but are not limited to the following:
filtration, ultrafiltration, diafiltration, centrifuge methods,
spray drying, spray granulating, etc.
[0054] This step (II) of concentrating and/or separating is
preferably performed prior step (W) of bringing the solid material
in contact with a composition containing water and after the step
(I) of crystallizing the solid material. The purpose of step (II)
is to increase the solid content in the mixture resulting from step
(I). For details of filtration and/or concentration, reference is
made to DE 10232406.9, the entire contents of which are hereby
incorporated by reference.
[0055] Preferably, the solid material is concentrated first and
then separated from the mother liquor by filtration. For example,
the method of ultrafiltration may be used for concentrating the
solid material in the retentate, while the solid material may be
separated from all or parts of the mother liquor by means of
conventional filtration. With respect to conventional filtration,
all methods known to the expert in the art may be used such as cake
filtration or methods involving a centrifuge.
[0056] In another-preferred embodiment, step (II) consists of
bringing an inert support body in contact with the synthesis
mixture from step (I). As far as the "inert support body" is
concerned, no limitations exist, so long as the inert support body
does not react noticeably with the synthesis mixture or any
component thereof and said inert support body is capable of
accommodating, at least partly, the solid material contained in the
synthesis mixture from step (I), preferably-in the form of a (thin)
film. Such inert support bodies may include but are not limited to:
beads or pellets made form technical ceramic materials such as
alumosilicate ceramics, alkali alumosilicate ceramics, aluminum
oxide based ceramics (e.g. mullit), magnesium silicates (e.g.
steatit, cordierit). The use of steatit or mullit is preferred.
Said inert support bodies may be porous or dense, wherein the use
of dense support bodies is preferred.
[0057] Said support bodies may be brought in contact with the
synthesis mixture from step (I) by means of all methods known to
expert in the context of bringing a solid body in contact with a
fluid medium. Spraying of the synthesis mixture onto the support
bodies, dipping the support bodies into the synthesis mixture or
saturating/soaking of the inert support bodies in the synthesis
mixture are preferred. In case the method of bringing in contact is
soaking/dipping/saturating, in a preferred embodiment, the
soaked/dipped,/saturated support bodies are exposed to an
atmosphere with a partial pressure of the liquid medium of the
synthesis mixture (e.g. water) lower than the pressure of the pure
liquid, so that the liquid medium may, at least partly,
evaporate.
[0058] As a result of said step of bringing inert support bodies in
contact with the synthesis mixture from step (I), a (thin) film
containing the solid material containing at least one zeolite and
being at least partly crystalline forms on the support body and/or
in the pores, if the support body is porous. The thickness of the
film so formed may range from 1 .mu.m to 1500 .mu.m. In a preferred
embodiment, the thickness of the film ranges from 5 .mu.m to 50
.mu.m. The result of this embodiment is referred to a "solid
material" in the context of the present application and is
processed the same way the solid material obtained by spray drying
or ultrafiltration.
[0059] The solid material obtained after step (II) may now be
optionally subjected to at least one step of washing and to at
least one step of drying of the solid material. Furthermore, after
the at least one step of drying, the solid material may also be
calcined at temperatures of 400.degree. C. and higher (see
description-of the step (C) of calcining given below).
[0060] Step (W): Treatment of the Solid Material With a Composition
Containing Water
[0061] Subsequent to step (II) of concentrating and/or separating,
the solid material may be subjected to a treatment of bringing the
solid material in contact with a composition containing water.
[0062] As far as the term "bringing in contact" is concerned, any
method is conceivable, in which the solid material is brought in
physical contact with a composition containing water. This
includes, but is not limited to: forming a slurry, suspension or
mixture of the solid material in or with the composition containing
water, the composition being preferably in a liquid phase, spraying
the solid material with the composition containing water,
subjecting the solid material to the composition containing water
in the form of vapor and/or steam. It is particularly preferred to
form a slurry of the solid material with the composition containing
water in a stirring tank.
[0063] Preferably, the same stirring tank is used for step (W) that
has already been used for crystallizing the solid material out of
the synthesis mixture. In order to further the physical contact
between the solid phase and the composition containing water, any
means for stirring or otherwise mechanically acting the mixture
containing the solid material and the composition containing water
known to the expert in this field can be employed. Other methods of
mixing and/or agitating, such as ultrasound agitation, magnetic
stirring and the like are conceivable as well. Preferably the
slurry of the solid material is brought in contact with a
composition containing water in a tank vessel with a mechanical
stirring device.
[0064] As far a the composition containing water is concerned, any
substance can be used that contains, at least in parts, water in
any of its modifications. These modifications include the liquid
phase, the solid phase, vapor, steam, super critical water.
Furthermore, the water may by mixed with other substances.
Preferably water is used as such in the liquid phase or as steam.
If water is used in the liquid phase, deionized water is preferred.
Any method to deionize water known to the expert in the art is
included, such as distillation or removing of electrolytes over an
ion exchanger. While not preferred, the use of water containing
salt and/or of water that is acidic or basic is conceivable as
well.
[0065] For specific applications, bringing the solid materials in
contact with an aqueous ammonia solution may be preferred. In this
case, a solution of ammonia in water is preferred, wherein the
content of ammonia in water, given in % by weight with respect to
the total weight, ranges from 5 to 60, preferably from 10 to 30. If
a composition containing water and ammonia is used, step (W) is
preferably performed at pressures elevated with respect to ambient
pressure and not exceeding several hundred bars.
[0066] As far as the ratio, given in weight-percent, between the
amount of solid material and the composition containing water is
concerned, no principal limitations exist, save for the fact that
the mixture or slurry should have viscous or hydraulic properties
conducive to mechanical stirring.
[0067] Furthermore, it is preferred that the treatment of bringing
the solid material in contact with a composition containing water
is performed at a temperature elevated with respect to room
temperature. Temperatures between room temperature and 750.degree.
C. are preferred. Temperatures between 100.degree. C. and
250.degree. C. are particularly preferred, while temperatures
between 120.degree. C. and 175.degree. C. are further
preferred.
[0068] The treatment (W) of the solid material with a composition
containing water can be performed with any type of solid material.
The solid material may be the material obtained from step (II)
without drying or calcining. However, it is preferred that the
solid material from step (II) has been dried and/or calcined before
the treatment. It is further preferred, that the solid material has
been washed, dried and optionally calcined prior to step (W). It is
further preferred that the solid material has been obtained by
spray granulation and/or ultrafiltration (in conjunction with
conventional filtering).
[0069] After the optional step (W) has been performed, i.e. after
the solid material has been brought into contact with the
composition containing water, the composition containing water may
be removed from the solid material and/or the solid material may be
concentrated in the composition containing water. To achieve this
end, step (II) may be repeated. This is, the mixture containing the
solid material and composition containing water may be subjected
to, example given, sprayed drying, ultrafiltration, or
ultrafiltration in conjunction with conventional filtration. It may
be only subjected to conventional filtration as well.
[0070] Step (III): Agglomerating/Ranulating
[0071] Subsequent to step (W), the solid particles can be increased
in their size using any method of agglomerating and/or granulating
known to the expert in the field. For a list of methods used in
this context, reference is made to DE 10232406.9, the respective
contents of which are hereby incorporated by reference.
[0072] Post-Treatment
[0073] In order to improve the catalytic performance of the end
product, subsequent to step (W) or to step (III) or subsequent to
both, it is optionally possible to perform at least one step of
post-treatment of the material, including but not limited to the
following steps: drying, washing, calcining, treating of the solid
material with a hydrogen peroxide solution. Any combination of
these steps is conceivable as well. It is also possible to treat
this solid material containing at least one zeolite material with
compounds containing alkaline metal, in order to transform the
zeolitic material from the H-form into the cationic form. The solid
material obtained after step (W) or after step (III) or after any
of the two steps in conjunction with any of the steps of post
treatment mentioned here, can then be processed further to a shaped
body, as described below.
[0074] Step (S): Shaping of the Solid Material
[0075] The starting point for the process to produce a shaped body
containing zeolite is either the solid material after step (II) or
the solid material after step (W) or the solid material after step
(II), optionally involving any of the steps of post-treatment
mentioned in the proceeding paragraph. As it has been mentioned
above, if the process so far has involved at least one step (W) of
bringing the solid material in contact with a composition
containing water, the material obtained after step (S) does not
need to be subjective to an step (W). However, if the solid
material so far has not been subjected to the treatment (W), the
step of bringing the shaped body in contact with at least one
composition containing water has to be performed after the step (S)
of shaping the solid material or after said step (S) in conjunction
with a step (C).
[0076] In any case, the step (S) of shaping the solid material
involves at least one step of forming a three dimensional material
that contains at least one zeolite material. As far as this
specific (at least one) step of shaping the solid materials is
concerned, reference is made to WO 98/55229 and to DE 10232406.9
whose respective content is incorporated into the present
application by reference.
[0077] Preferably, a binding material is added to the solid
material resulting from any of the steps mentioned above. Further
adjuvants that may be added to the solid material prior to the step
(S) include but are not limited to: mixtures containing at least
one alcohol and water, if suitable one or more organic substances
increasing the viscosity, and further substances known from the
prior art.
[0078] Preferably, the solid material is milled and mixed with
silica sol, a dispersion of polystyrene, cellulose and
polyethlylene oxide (PEO), as well as with water. Said mixture is
homogenized in any type of kneading apparatus. In lieu of kneading,
any method of bringing the substances into physical contact may be
used. Preferably, the mass obtained by this method shows plastic
flow. The shaped body can then be obtained from this mass, example
given, by means of molding, in particular extrusion molding, or by
any other method of extrusion known to the expert in the field.
[0079] As far as the binding materials are concerned, in principle,
every substance can be used that achieves cohesion between the
particles that is increased over the cohesion achieved without the
presence of the binding material. Preferred binding materials are
selected from the following group consisting of hydrated silica
gel, silicic acid, tetraalkoxy silicates, tetraalkoxy titanates,
tetraalkoxy zirconates or mixtures of two or more of the
aforementioned substances. Tetraalkoxy silicates such as
tetramethoxy silicates, tetraethoxy silicates, tetrapropoxy
silicates or tetrabutoxy silicates are p referred. Tetramethoxy
silicates or tetraethoxy silicates and silica sols are particularly
preferred.
[0080] Further preferred binding materials are amphiphilic
substances, i.e. molecules with a polar and a non-polar part The
use of graphite is conceivable as well. As far as further binding
materials are concerned, reference is made to WO 98/55229 and to DE
10232406.9 whose respective content is incorporated into the
present application by reference.
[0081] Said binding materials can be used either alone or as
mixtures of two or more of these, or they can be used together with
other materials to be used for enabling or enhancing the binding of
materials containing zeolite, such as oxides of silicate, bor,
phosphor, zirconium, and/or titanium. By way of example, clays are
also to be mentioned.
[0082] In the process of shaping the solid material into a shaped
body, up to approximately 80% by weight of binding materials with
respect to the total mass of the shaped body are to be used. It is
preferred to use from approximately 10 to approximately 75% by
weight of binding materials, while using 25% to approximately 45%
is particularly preferred
[0083] In the framework of the process to produce a shaped body,
polymers may be added with the intent to create pores of a certain
size, a certain volume or a certain size distribution. In the
context of the present invention, polymers are preferred that can
be dispersed, emulsified or suspended in aqueous solvents. Said at
least one polymer is preferably selected from the group of polymer
vinyl compounds, such as polystyrene, polyaciylates,
polymethacrylates, polyolefins, polyaminds, or polyesters. These
polymers are removed from the shaped bodies after the process of
forming and/or shaping by means of calcining the shaped body. If
polymers are added, the content of polymer during the production of
the shaped body amounts to from approx. 5 to approx. 90% by weight,
preferably from approx. 15 to approx. 75% by weight, wherein a
content ranging from 25 to 55% by weight is particularly preferred.
The amounts given in weight-% refer to the amount of polymer in the
solid material containing zeolite, respectively.
[0084] Furthermore, it is preferred to add a pasting agent. As far
as the pasting agent is concerned, any substances known from the
prior art to improve the mixing, kneading, or flow properties of
the mass can be used. Preferably, organic hydrophilic polymers are
used, such as cellulose, starch, polyacrylates, polymethacrylates,
polyvinylalcohol, polyvinyl pyrrolidon, polyisobutene,
polytetrahydrofuran. Primarily, these substances enable or improve
the formation of a plastic mass durng the process of kneading,
forming, and/or drying by means of bridging the primary particles.
Moreover, these adjuvants enable or enhance the mechanical
stability of the shaped body during the steps of forming or
drying.
[0085] These substances are removed from the shaped body by means
of calcining after the step of shaping. Further adjuvants are
described in EP-A 0 389 041, EP-A 0 200 260, and in WO 95/19222,
the entire contents of which are hereby incorporated by
reference.
[0086] In a preferred embodiment, after having added the binding
material to the solid material containing at least one zeolite, the
organic substance increasing viscosity is added and the mass is
homogenized for 10 to 180 minutes in the kneading appaatus or in
the extruder. The temperature applied to the mass is typically
about 10.degree. C. under the boiling point of the pasting agent.
The pressure is either ambient pressure or is slight over-pressure.
In principle, the order of adding additional components to the
solid material and the binder is not believed to be critical. The
mass obtained as described above is kneaded until a plastic mass
can be extruded.
[0087] In the context of the present invention, those methods for
forming a shaped body from a solid material are preferred, in which
the forming can be performed in commercially available extruders.
Preferably, extrudates of a diameter ranging from approx. 1 to
approx. 10 mm are used, particularly preferred are extrudates with
diameters ranging from approx. 2 to approx. 5 mm. Extruders that
can be used in the context of the steps described here are
descnred, for example, in "Ullmann's Enzyklopdie der Technischen
Chemie", 4.sup.th Edition, Vol. 2, p. 205 ff. (1972).
[0088] In principle, all methods of shaping and of forming that are
known to the expert in the art can be used. Next to extrusion,
other known methods are briquetting, pelleting, pressing,
sintering, or roasting.
[0089] The technique of co-extruding can be employed as well. Here,
two materials are co-extruded simultaneously. Preferably the afore
described active material (solid material according to the
invention) is extruded together with an inert material i.e. a
material that does not react noticeably with the active material.
Preferably, the matrix of the extruder is designed so that the
active material is extruded as a layer on the inert material.
Therefore, strands result, whose core is made of the inert material
and whose outer layer is the active solid material. In a preferred
embodiment, the thickness of the active layer ranges from 1 to 1500
.mu.m, preferably from 5 to 50 .mu.m
[0090] The use of binding materials or other adjuvants is in any
event optional. The materials to be compacted may be dry or moist
or may prevail as a slurry.
[0091] The step of shaping and/or forming can be performed at
ambient pressure or at a pressure that is elevated with respect to
ambient pressure, for example, in a pressure range from 1 bar to
700 bars. Furthermore, the shaping and/or forming can be performed
at ambient temperature or at a temperature increased with respect
to ambient temperature, example given, a temperature which is
ranging from 20.degree. C. to approx. 300.degree. C. If drying
and/or sintering is part of the shaping and/or forming step,
temperatures of up to 1500.degree. C. are conceivable. Furthermore,
the step of compacting and of forming can be performed at ambient
atmosphere or in a controlled atmosphere. Controlled atmospheres
include but are not limited to inert gas atmospheres, reducing
atmospheres, or oxidizing atmospheres.
[0092] Post-Treatment of the Shaped Bode
[0093] After forming and/or shaping (S) the shaped bodies, they are
typically dried at temperatures ranging from approx. 30.degree. C.
to approx. 140.degree. C. for a time interval ranging, typically
from 1 h to 20 h. Subsequent to this step, the shaped body is
calcined at temperatures ranging from approx. 400.degree. C. to
approx. 800.degree. C. and for a time interval ranging from approx.
3 h to approx. 10 h. Calcining can be performed at ambient
pressure, preferably in air or in a mixture containing air or under
inert conditions.
[0094] In another step of post-treatment, the extrudates obtained
as described above may be milled and/or crushed. The milling and/or
crushing preferably leads to a granulate with an average particle
diameter ranging from 0.1 to approx. 5 mm. Particle diameters
ranging from approx. 0.5 to 2 mm are particularly preferred.
[0095] Subsequent to the step (S) or subsequent to said step (S) in
conjunction with any step of post-treatments such as (in
particular) drying and calcining, the treatment of bringing the
solid material, in this case a shaped body, in contact with a
material containing water, i.e., the step (W) may be performed.
[0096] If the step (W) is performed at this point, i.e. after the
step (S) or the steps (S) and (C) in conjunction, everything that
has been disclosed before about the specific embodiments of said
step of (W) is valid here as well. In a preferred embodiment,
however, the shaped body is charged into the reactor that is used
for the desired reaction, typically an epoxidation reaction, and
said shaped body, is subjected to the treatment with the
composition containing water, in the reactor. Preferably the
treatment consists in exposing and/or bringing in contact of the
shaped body with water steam.
[0097] In addition to the process for producing a solid material
and/or a shaped body as described above, the present invention also
relates to the respective material or shaped body as such.
[0098] In particular, the solid material according to the invention
is obtainable by a sequence of the following steps:
[0099] (I) at least partial crystallization of at least one solid
material containing at least one zeolite out of a synthesis
mixture, resulting in mixture (I) containing at least said solid
material and a mother liquor,
[0100] (II) separating and/or concentrating of the solid material
from mixture (I);
[0101] (W) bringing the solid material from step (II) in contact
with a composition containing water,
[0102] (III) agglomerating or granulating or agglomerating and
granulating of the solid material from step (W);
[0103] wherein the steps (III) and (W) are optional. Step (II) may
additionally include the drying and/or washing of the solid
material, possibly also in several iterations.
[0104] Here, the inventive partial step (Ib) is part of the above
mentioned step (I):
[0105] (Ia) mixing of at least one hydrolyzable silicon source with
a mineralizing and/or structuring agent and water;
[0106] (Ib) mixing of at least one transition metal oxide source
with an epoxide or a hydrolysate thereof;
[0107] (Ic) mixing of the mixtures from (Ia) and (Ib) so that at
least a part of the hydrolyzable compounds hydrolyzes;
[0108] (Id) distilling at least parts of the alcohol that has been
formed as a result of the at least partial hydrolysation of at
least part of the hydrolyzable compounds;
[0109] (Ie) adding water to the bottom of (Id);
[0110] (If) reacting of the synthesis mixture resulting from (Ie)
at a temperature elevated with respect to room temperature.
[0111] Furthermore, the present invention relates to a shaped body
obtained from the solid material described above. The shaped body
is obtained by subjecting the solid material to a step (S) of
shaping, as described in detail above, and (optionally) to a step
(C) of calcining. The sequence of the steps is schematically shown
below:
[0112] (I) at least partial crystallization of at least one solid
material containing at least one zeolite out of a synthesis
mixture, as described above in (Ia) to (If), resulting in mixture
(I) containing at least said solid material and a mother
liquor;
[0113] (II) separating and/or concentrating of the solid material
in mixture (I);
[0114] (III) agglomerating or granulating or agglomerating and
granulating of the solid material from step (W);
[0115] (S) shaping of the solid material from step (II) or
(III)
[0116] Hereby, the following step (W) can optionally be performed
after step (II) or after step (S) or after step (II) and after step
(S):
[0117] (W) bringing the shaped body from step (S) in contact with a
composition containing water;
[0118] Finally the present invention relates to the use of the
inventive materials, i.e. the solid material and/or the shaped
bodies as catalysts. The materials obtainable by the inventive
process or the materials obtained by the inventive process are
particularly suited for catalytic reactions involving compounds
with at least one C--C-double bond. Particularly preferred is the
reaction of at least one compound containing at least one
C--C-double bound with at least one hydrogen peroxide. These
reactions are also referred to as epoxidation reactions. As far as
further possible reactions are concerned for which said catalysts
maybe employed, reference is made to DE 102 32 406.9 the respective
contents of which (in particular pages 27 and 28) are hereby
incorporated by reference.
EXAMPLE C1
COMPARATIVE EXAMPLE
[0119] In a four neck flask, 658 g of tetraethoxysilane are mixed
with 20.8 g of tetraethylorthotitanate. While stirring, a solution
of 340 g of tetrapropylaiimoniumhydroxide (40% by weight, in water)
and 563 g of deionized water is added slowly thereto.
[0120] The solution is stirred at room temperature for one hour.
Subsequently, the alcohol formed due to hydrolysis is distilled at
a bottom temperature of 92.degree. C. The bottom (915 g) is filled
with water to 1600 g.
[0121] This batch is reacted in a steel autoclave at 175.degree. C.
and for 24 hours while being stirred After the mixture has cooled
down, it consists of a white suspension. Therefrom, the solid
material is filtrated, rinsed with water and dried at 120.degree.
C. for 24 hours. Subsequently, said material is calcined in air two
times for 5 hours, respectively, at a temperature of 450.degree.
C.
[0122] The yield in isolated solid material is 190 g. The content
in Ti of the zeolite of MFI--structure thus obtained is 2.1% by
weight.
[0123] The following test of the catalytic material as described
above has been performed: In a pressure-tight glass reactor, 0.5 g
of said catalyst was mixed with 45 ml of methanol. At a temperature
of 0.degree. C., 20 ml of propylene were dosed in and subsequently,
by means of a pump, 18 g of hydrogen peroxide (30% by weight, in
water; Merck) were metered in. After a reaction time of 5 hours,
the mixture is expanded (pressure relieved) and the liquid phase is
analyzed by means of gas chromatography. The reaction mixture
contains 8.7% by weight of propylene oxide.
EXAMPLE C2
[0124] The catalyst material as described above is shaped into a
shaped body according to the following procedure: 60 g of the
inventive solid material as described in Example C1 are milled and
mixed with the following substances: 56.5 g of silica sol (Ludox AS
40% by weight SiO.sub.2), a total amount of 32.9 g of a polystyrene
dispersion (43.5 weight % of polymer), 2.7 g of methyl cellulose
(Walocel) and 0.88 g of polyethylene oxide (PEO). 20 g of water are
added to the mass. Said mass is homogenized in a kneading
apparatus.
[0125] However, the materials are not added at the same time.
Specifically, during the process of kneading, the polystyrene
dispersion is added within 5 minutes, and after 10 minutes the
silica sol is added slowly. After 10 further minutes of kneading,
the PEO is added and gobbled for a further 10 minutes.
Subsequently, water is added in portions of 5 ml, respectively.
[0126] The paste so obtained is formed after a total of 60 minutes
of kneading and at a extrusion pressure of 70 bars via a extruder
having a matrix of 1.5 nm holes. This way the solid material is
alternately formed into strands.
[0127] The shaped body obtained this way is dried for four hours at
120.degree. C. (heating ramp of 2 K per minute). Finally, the
shaped body is calcined at 490.degree. C. for four hours (heating
ramp 1 K per minute). The atmosphere is air. The yield is 65.24 g.
The content in titainium of the shaped body produced this way is
1.4% by weight.
[0128] Said shaped body was subjected to a long term test for
selectivity: 13.5 g of the shaped bodies were loaded into a tube
reactor (1.3 m length). The catalyst was exposed at a pressure of
about 20 bars to a feed of 48 g/hour of methanol, 8.2 g/hour of
hydrogen peroxide (40% by weight) and 4.7 g/bour of propylene (96%
by volume of propylene). Temperatures were regulated between 20 and
40.degree. C.
[0129] The analysis of the product mixture emerging from the
reactor results in that after 230 hours, the selectivity for
propylene oxide (with respect to H.sub.2O.sub.2) was 91%. The
formation of oxygen (selectivity with respect to H.sub.2O.sub.2)was
measured to be 2.4% and the unwanted side product methoxy propanol
was formed with a selectivity of 3.3%.
EXAMPLE 1
Catalyst According to the Present Invention
[0130] In a four neck flask, 613 g of tetraethoxysilane are mixed
with a solution of 316 g of tetrapropylamnoniumhydroxide (40% by
weight, in water) and 523 g of deionized water.
[0131] Separately, 18.1 g of tetrabutylorthotitanate are dissolved
in 109 g of propylene glycol until a clear solution forms.
[0132] Said solution is dosed dropwise into the mixture of
tetraethoxysilane and tetrapropylammoniumhydroxide described above.
The resulting solution is stirred for 30 minutes. Subsequently, the
alcohol formed due to hydrolysis is distilled at a bottom
temperature of 92.degree. C. The bottom (953 g) is filled with
water to 1600 g.
[0133] This batch is reacted in a steel autoclave at 175.degree. C.
and for 24 hours while being stirred. The cooled down mixture
consists of a white suspension. Therefrom, the solid material is
filtrated, rinsed with water and dried at 120.degree. C. for 24
hours. The yield of dried product was 209 g Subsequently, said
material is calcined in air two times for 5 hours, respectively, at
a temperature of 450.degree. C. The mass loss due to calcination
was measured to be 13% by weight.
[0134] The content in Ti of the zeolite of MFI-structure thus
obtained is 1.9% by weight
[0135] The following test of the catalytic material as described
above has been performed: In a pressure-tight glass reactor, 0.5 g
of said catalyst was mixed with 45 ml of methanol. At a temperature
of 0.degree. C., 20 ml of propylene were dosed in and subsequently,
by means of a pump, 18 g of hydrogen peroxide (30% by weight, in
water, Merck) were metered in. After a reaction time of 5 hours,
the mixture is expanded (pressure relieved) and the liquid phase is
analyzed by means of gas chromatography. The reaction mixture
contains 9.7% by weight of propylene oxide. Despite the lower
content in Ti of the zeolite, the inventive catalyst is shown to be
significantly more active than the respective catalyst from the
comparative example C1.
EXAMPLE 2
Catalyst According to the Present Invention
[0136] The catalyst material as described in Example 1 is shaped
into a shaped body according to the following procedure: 60 g of
the inventive solid material as described in Example 1 are milled
and mixed with the following substances: 56.5 g of silica sol
(Ludox AS 40% by weight SiO.sub.2), a total amount of 32.9 g of a
polystyrene dispersion (43.5 weight % of polymer), 2.7 g of methyl
cellulose (Walocel) and 0.88 g of polyethylene oxide (PEO). 20 g of
water are added to the mass. Said mass is homogenized in a kneading
apparatus.
[0137] However, the materials are not added at the same time.
Specifically, during the process of kneading, the polystyrene
dispersion is added within 5 minutes, and after 10 minutes the
silica sol is added slowly. After 10 further minutes of kneading,
the PEO is added and gobbled for a further 10 minutes.
Subsequently, water is added in portions of 5 ml, respectively.
[0138] The paste so obtained is formed after a total of 60 minutes
of kneading and at a extrusion pressure of 70 bars via a extruder
having a matrix of 1.5 mm holes. This way the solid material is
alternately formed into strands.
[0139] The shaped body contained this way is dried for four hours
at 120.degree. C. (heating ramp of 2 K per minute). Finally, the
shaped body is calcined at 490.degree. C. for four hours (heating
ramp 1 K per minute). The atmosphere is air. The yield is 65.24 g.
The content in titainium of the shaped body produced this way is
1.1% by weight.
[0140] Said shaped body was subjected to a long term test for
selectivity: 13.5 g of the shaped bodies were loaded into a tube
reactor (1.3 m length). The catalyst was exposed at a pressure of
about 20 bars to a feed of 48 g/hour of methanol, 8.2 g/hour of
hydrogen peroxide (40% by weight) and 4.7 g/bour of propylene (96%
by volume of propylene). Temperatures were regulated between 20 and
40.degree. C.
[0141] The analysis of the product mixture emerging from the
reactor results in that after 215 hours, the selectivity for
propylene oxide (with respect to H.sub.2O.sub.2) was 95.3%. The
formation of oxygen (selectivity with respect to H.sub.2O.sub.2)was
measured to be 0.6% and the unwanted side product methoxy propanol
was formed with a selectivity of 2.4%.
[0142] Therefore, the catalyst of the invention not only shows
increased activity over a catalyst that has not been subjected to
the inventive partial step, but is otherwise obtained the same way,
but also improved selectivity.
* * * * *