U.S. patent application number 10/244527 was filed with the patent office on 2004-03-18 for process for epoxidation and catalyst to be used therein.
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 | 20040054199 10/244527 |
Document ID | / |
Family ID | 31991907 |
Filed Date | 2004-03-18 |
United States Patent
Application |
20040054199 |
Kind Code |
A1 |
Muller, Ulrich ; et
al. |
March 18, 2004 |
Process for epoxidation and catalyst to be used therein
Abstract
The present invention relates to a process for treating a solid
material containing at least one zeolite and being at least partly
crystalline or treating a shaped body obtained from said solid
material wherein said solid material or shaped body is brought in
contact with a composition containing water after at least one of
the following steps of an integrated process for producing a solid
material or a shaped body containing at least one zeolite: (i)
after step (II) of separating the at least partly crystalline solid
material from its mother liquor or (ii) after step (S) of shaping
said solid material into a shaped body or (iii) after a step (C) of
calcining said solid material or said shaped body. The present
invention furthermore relates to the solid material obtainable by
the inventive process and the shaped body obtainable by the
inventive process. The present invention finally relates to the use
of the solid material or the shaped body as mentioned above as a
catalyst in chemical reactions, in particular in reactions of
compounds containing at least one C--C double bond with at least
one hydroperoxide.
Inventors: |
Muller, Ulrich; (Neustadt,
DE) ; Krug, Georg; (Morlenbach, DE) ; Bassler,
Peter; (Viernheim, DE) ; Gobbel, Hans-Georg;
(Kallstadt, DE) ; Rudolf, Peter; (Ladenburg,
DE) ; Teles, Joaquim Henrique; (Otterstadt,
DE) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
BASF Aktiengesellschaft
Ludwigshafen
DE
|
Family ID: |
31991907 |
Appl. No.: |
10/244527 |
Filed: |
September 17, 2002 |
Current U.S.
Class: |
549/523 ;
423/700 |
Current CPC
Class: |
C07D 301/12 20130101;
C07D 301/19 20130101; B01J 2229/36 20130101; Y02P 20/10 20151101;
B01J 29/89 20130101; B01J 37/10 20130101; B01J 2229/40
20130101 |
Class at
Publication: |
549/523 ;
423/700 |
International
Class: |
C07D 301/03 |
Claims
We claim
1. Process for treating a solid material or a shaped body
containing at least one zeolite and being at least partly
crystalline characterized in that said solid material or the shaped
body is brought in contact with a composition containing water
after at least one of the following steps of an integrated process
for producing a solid material or a shaped body: (i) after step
(II) of separating the at least partly crystalline solid material
from its mother liquor or (ii) after step (S) of shaping said solid
material into a shaped body or (iii) after a step (C) of calcining
said solid material or said shaped body.
2. Process according to claim 1, characterized in that the solid
material is brought in contact with a composition containing water
at temperatures elevated with respect to room temperature.
3. Process according to claim 1, characterized in that the
composition containing water is selected from the following group
comprising: deionized water, water vapor, steam, steam at pressures
elevated relative to ambient pressure, supercritical water, aqueous
solutions, ammonia water.
4. Process according to any of claims 1 to 3, characterized in that
the at least one zeolite contains Ti.
5. Process according to claim 4, characterized in that the at least
one zeolite containing Ti is selected from materials of the
structure classes MFI, MEL, MWW, BEA or any mixed structures
thereof.
6. Process according to claim 1, characterized in that the step of
bringing the solid material or the shaped body in contact with a
composition containing water is performed in a reactor that is used
for the synthesis or treatment of the solid material or in a
reactor in which the solid material or the shaped bodies made form
the solid material are used as catalysts in a chemical
reaction.
7. Integrated process for the production of a solid material
containing at least one zeolite, comprising at least the following
steps: (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; (II) separating and/or concentrating
of the solid material in mixture (I); (W) bringing the solid
material from step (II) in contact with a composition containing
water; (III) agglomerating or granulating or agglomerating and
granulating of the solid material from step (W); wherein step (m)
is optional.
8. Integrated process according to claim 7, characterized in that
after step (W), the solid material is separated from at least parts
of the composition containing water, i.e. a repetition of step (II)
is performed.
9. Integrated process according to claim 7, characterized in that
the method of separating and/or concentrating in step (II) is
selected from the following group consisting of: ultrafiltration,
spray-drying, spray granulating, bringing inert support bodies in
contact with the synthesis solution from (I).
10. Integrated process for the production of a shaped body
containing at least one zeolite, comprising at least the following
steps: (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; (II) separating and/or concentrating
of the solid material in mixture (I); (W) bringing the solid
material from step (II) in contact with a composition containing
water; (III) agglomerating or granulating or agglomerating and
granulating of the solid material from step (W); wherein step (III)
is optional and wherein, after step (W) or after step (III), at
least one step (S) of shaping the solid material into a shaped body
is performed.
11. Integrated process according to claim 10, characterized in that
the at least one step of shaping the solid material is selected
from the following group comprising: pelletizing, pressing,
extruding, sintering, roasting, briquetting.
12. Integrated process according to claim 10, characterized in that
the step (W) is performed after the step (S) of shaping the solid
material is performed, wherein said step (W) either replaces the
step (W) performed after step (II) or is performed in addition to
the step (W) performed after step (II).
13. Integrated Process according to any of the claims 7 to 12,
characterized in that after at least one of the steps (II), (W) or
(III), a step (C) of calcining the solid material and/or the shaped
body is performed.
14. Integrated process according to claim 13, characterized in that
said step of calcining is performed at temperatures higher than
400.degree. C.
15. Solid material obtainable by a process of treating a solid
material containing at least one zeolite and being at least partly
crystalline, wherein said solid material is brought in contact with
a composition containing water after at least one of the following
steps of an integrated process for producing said solid material:
(i) after step (II) of separating the at least partly crystalline
material from its mother liquor or (ii) after a step (C) of
calcining said solid material or said shaped body.
16. Solid material according to claim 15, characterized in that it
contains Ti.
17. Solid material according to claim 15, characterized in that it
displays a discernible hump, i.e. an increased UV/VIS absorption,
over materials that have not been brought in contact with a
composition containing water, in the region from 250 to 350 nm.
18. Solid material according to any of the claims 15 to 17,
characterized in that it is shaped into a shaped body in a step (S)
and that in addition to the step of bringing the solid material in
contact with a composition containing water or instead of said
step, the shaped body is brought in contact with a composition
containing water, either directly after the step (S) of shaping the
solid material into a shaped body or after a subsequent step (C) of
calcining said shaped body.
19. Use of the solid material or the shaped body according to any
of the claims 15 to 18 or of the solid material or the shaped body
obtained according to any of the claims 1 to 14 as a catalyst or a
co-catalyst in the reaction of at least one compound with at least
one C--C-double bond with at least one hydroperoxide.
Description
[0001] The present invention relates to a process for treating a
solid material containing at least one zeolite and being at least
partly crystalline or treating a shaped body obtained from said
solid material wherein said solid material or shaped body is
brought in contact with a composition containing water after at
least one of the following steps of an integrated process for
producing a solid material or a shape body containing at least one
zeolite: (i) after step (II) of separating the at least partly
crystalline solid material from its mother liquor or (ii) after
step (S) of shaping said solid material into a shaped body or (iii)
after a step (C) of calcining said solid material or said shaped
body. The present invention furthermore relates to the solid
material obtainable by the inventive process and the shaped body
obtainable by the inventive process. The present invention finally
relates to the use of the solid material or the shaped body as
mentioned above as a catalyst in chemical reactions, in particular
in reactions of compounds containing at least one C--C double bond
with at least one hydroperoxide.
[0002] Integrated processes for the manufacture of solid materials
containing a zeolite and said solid materials as such are described
in the prior art. Particularly to be mentioned is WO 98/5529. The
focus of this reference is on the binding materials used to forming
and/or compacting the solid materials containing a zeolite into a
shaped body. The WO 98/5529 is silent as to a treatment of the
solid material obtained from the synthesis solution with any
composition containing water.
[0003] Also to be mentioned is DE 102 32 406.9 which relates to an
integrated process for manufacturing solid materials containing a
zeolite. Said document describes various methods for separating the
solid material from its mother liquor, including methods of
ultra-filtration and spray-drying. However, said document does not
teach the subsequent treatment of the materials so separated from
the mother liquor with a composition containing water or such a
treatment at any other subsequent stage of the integrated
process.
[0004] The object of the present invention was to provide a process
for producing a solid material or a shaped body containing at least
one zeolite and being at least partially crystalline, wherein said
process provides a catalytic material is improved over the
materials of the prior art with respect to at least one catalytic
performance characteristic.
[0005] Surprisingly, it has been found that the catalytic
properties of solid materials containing at least one zeolite can
be significantly improved, in particular with respect to their
selectivity, if the solid material is subjected to an additional
treatment with a composition containing water. The inventive step
of treating the solid material containing zeolite with a
composition containing water can be performed after at least one of
the following two steps of the integrated process for producing a
solid material containing at least one zeolite: (i) after step (II)
of separating the at least partly crystalline solid material from
its mother liquor or (ii) after a step (C) of calcining said solid
material.
[0006] Similarly, the catalytic properties of a shaped body are
improved if the shaped body is subjected to the inventive treatment
with a composition containing water after a step (S) of shaping a
shaped body from the solid material described above, optionally in
conjunction with a step (C) of calcining.
[0007] Advantageously, the treatment of the solid material
containing at least one zeolite with a composition containing
water, can be performed in either the reactor that is used for
synthesizing the solid material containing at least one zeolite
(autoclave) or in the reactor in which the solid material or the
shaped bodies made from said solid materials are used as catalysts,
i.e. in the reaction container. Therefore, the inventive process
does not require an additional (reaction) stage.
[0008] The catalytic material (solid material or shaped body)
obtainable by the inventive process described above 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 with a composition containing water.
[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.
[0010] The present invention relates to the above-described process
for producing a solid material containing at least one zeolite, to
the solid material obtainable by this process, to the shaped body
obtainable from the solid material that is produced according to
the inventive process, as well as to use of the solid material
and/or the shaped body in chemical reactions, in particular in
epoxidation reactions.
[0011] In the following, a glossary of the most important
expressions used in the framework of the present invention are
defined.
[0012] 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.
[0013] As far as the phases involved in or resulting from the
reaction of the synthesis mixture are concerned, after the reaction
of the synthesis mixture, it is preferred to obtain a mother liquor
containing a solid material in suspension. In the context of the
present application, the solid material should be (i) at least
partially crystalline and (ii) contain at least one zeolite
material.
[0014] "Zeolites" as used in the context of the present invention
are crystalline alumosilicates with well-ordered channel or cage
structures containing micropores. The expression "micropore" 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-tetrahedra that are bridged via shared oxygen bonds. An
overview of the known structures can be found in, example given, W.
M. Meier und 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.
[0015] "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.
[0016] 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).
[0017] 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.
[0018] 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.
[0019] 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).
[0020] 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.
[0021] 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 material into
a shaped body as well. Reference is made to the description of
binding materials in that context.
[0022] The inventive treatment of a solid material or a shaped body
produced therefrom, both containing at least one zeolite and being
at least partially crystalline, with a composition containing water
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:
[0023] (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;
[0024] (II) separating and/or concentrating of the solid material
from mixture (I);
[0025] (W) bringing the solid material from step (II) in contact
with a composition containing water;
[0026] (III) agglomerating or granulating or agglomerating and
granulating of the solid material from step (W);
[0027] wherein step (III) is optional. Step (II) may additionally
include the drying and/or washing of the solid material, possibly
also in several iterations.
[0028] In a preferred embodiment, step (II) is repeated after step
(W).
[0029] Additionally, and/or optionally the following steps may be
part of the integrated process as well:
[0030] (S) shaping of the solid material into shaped bodies
subsequent to steps (W) or (III);
[0031] (C) Calcining of the solid material and/or the shaped body
at temperatures higher than 400.degree. C.;
[0032] 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).
[0033] In a preferred embodiment, step (W) is performed after step
(S) of shaping the solid material, wherein said step (W) either
replaces the step (W) performed after step (II), as described in
the embodiment above, or is performed in addition to a step (W)
performed after step (II).
[0034] 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.
[0035] 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 (W) representing
the inventive step.
[0036] Step I: (Partial) Crystallization of the Synthesis
Mixture
[0037] As far as the least one zeolite material to be present in
the inventive solid material and/or the inventive shaped body 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.
[0038] 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.
[0039] 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.
[0040] Typically, said zeolites containing titanium, zirconium,
niobium, iron, and/or vanadium are produced by starting with a
synthesis mixture, i.e. an aqueous solution of a SiO.sub.2-source,
a source for titanium, zirconium, chromium, niobium, iron, and/or
vanadium, such as titanium oxide, titanium dioxide, or the
respective metal oxide, as well as an organic base containing
nitrogen to be used as a template. The term "template", in this
context refers to materials that can be used as a mineralizing
agent or as a structuring agent or both.
[0041] If necessary, or advantageous, additional compounds may be
added. The reaction of the synthesis mixture is performed in a
pressure-tight container (autoclave) at elevated temperatures over
the course of several hours or days. Thereby, a product that is at
least partly crystalline is obtained. In the context of the present
invention, this step of producing a solid material containing
zeolite and being at least partly crystalline,is referred to as
step (I).
[0042] In the context of step (I), in a preferred embodiment, at
least one template substance is used that yields a specific and
desired pore size. In principle there are no restriction with
respect to the at least one template substance, apart from the fact
that said template substances have to contribute, at least partly,
to pore formation. Suited template compounds may be quaternary
ammonium salts such as tetrapropylammonium hydroxide,
tetrapropylammoniumbromide, tetraethylammoniumhydroxide,
tetraethylammonium bromide or diamine or other template substances
known from the literature.
[0043] 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-, CFI-, 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-, MET-, MEL-, MEP-, MER-, NFI-, NWS-, 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.
[0044] 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", "TS-2" or "TS-3", as well as zeolites
containing titanium displaying a structure that is isomorphous to
.beta.-zeolite.
[0045] Step (II): Separating and/or Concentrating
[0046] 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.
[0047] This step (II) of concentrating and/or separating is
preferably performed prior to the inventive 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.
[0048] 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.
[0049] In a 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.
[0050] 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.
[0051] 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.
[0052] 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).
[0053] Step (W): Treatment of the Solid Material with a Composition
Containing Water
[0054] Subsequent to step (II) of concentrating and/or separating,
the solid material may be subjected to the inventive treatment of
bringing the solid material in contact with a composition
containing water.
[0055] 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.
[0056] 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.
[0057] 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.
[0058] For specific applications, bringing the solid material 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.
[0059] 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.
[0060] 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.
[0061] As far as the duration of the inventive treatment is
concerned, no limitations exist, so long as the treatment results
in an improved performance of the catalyst over a catalyst that had
not been subjected to that treatment. 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 treatment is
performed for the duration of 12 to 24 hours.
[0062] The inventive 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 inventive 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).
[0063] In a preferred embodiment, performing step (W) after step
(II) is optional if, but only if, the step (W) is performed at a
later stage of the integrated process, for example after step (S)
as described below or after step (S) in conjunction with step (C).
In summary, step (W) has to be performed at least once during the
integrated process for producing a solid material or a shaped body
containing at least one zeolite.
[0064] After 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.
[0065] Step (III): Agglomerating/Granulating
[0066] 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.
[0067] Post-Treatment
[0068] 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.
[0069] Step (S): Shaping of the Solid Material
[0070] 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
(III), 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 inventive step (W). However, if the
solid material so far has not been subjected to the inventive
treatment (W), the inventive 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).
[0071] 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.
[0072] 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.
[0073] 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.
[0074] 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
afore-mentioned substances. Tetraalkoxy silicates such as
tetramethoxy silicates, tetraethoxy silicates, tetrapropoxy
silicates or tetrabutoxy silicates are preferred. Tetramethoxy
silicates or tetraethoxy silicates and silica sols are particularly
preferred.
[0075] 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 98155229 and to DE
10232406.9 whose respective content is incorporated into the
present application by reference.
[0076] 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.
[0077] 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.
[0078] 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, polyacrylates,
polymethacrylates, polyolefins, polyamids, 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.
[0079] 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 during 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.
[0080] 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.
[0081] 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 apparatus 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.
[0082] 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
described, for example, in "Ullmann's Enzyklopdie der Technischen
Chemie", 4.sup.th Edition, Vol. 2, p. 205 if. (1972).
[0083] 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.
[0084] The technique of co-extruding can be employed as well. Here,
two materials are co-extruded simultaneously. Preferably the
aforedescribed 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.
[0085] 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.
[0086] 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.
[0087] Post-Treatment of the Shaped Body
[0088] 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.
[0089] 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.
[0090] 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 inventive 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. If the step (W) has not been performed at any point
during the integrated process as described above, the
implementation of the step (W) at this point is mandatory. If said
step (W) has been performed before at least once, the
implementation of said step is optional.
[0091] 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.
[0092] 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 as such.
[0093] First of all, the invention relates to a solid material
obtainable by a process of treating a solid material containing at
least one zeolite and being at least partly crystalline, wherein
said solid material is brought in contact with a composition
containing water after at least one of the following steps of an
integrated process for producing said solid material: (i) after
step (II) of concentrating or separating the at least partly
crystalline solid material from its mother liquor via, example
given, filtration or spray drying, or (ii) after the same step with
the additional optional step of drying and/or calcining (C) of the
solid material.
[0094] In particular, the solid material is obtainable by a
sequence of the following steps:
[0095] (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;
[0096] (II) separating and/or concentrating of the solid material
from mixture (I);
[0097] (W) bringing the solid material from step (II) in contact
with a composition containing water;
[0098] (III) agglomerating or granulating or agglomerating and
granulating of the solid material from step (W);
[0099] wherein step (III) is optional. Step (II) may additionally
include the drying and/or washing of the solid material, possibly
also in several iterations. In a preferred embodiment, step (II) is
repeated after step (W).
[0100] Said inventive solid material is further characterized by
its particular UV/VIS spectra. These spectra clearly indicate, that
the material obtained by the inventive process is different from
the material that is obtained without using the inventive treatment
of bringing the solid material in contact with a composition
containing water. This is illustrated in FIG. 1.
[0101] FIG. 1 shows on the horizontal axis, i.e. the x-axis, the
UV/VIS wavelength given in nm and it shows on the vertical axis,
i.e. the y axis, the absorbance in Kubelka-Munk representation.
Starting from the left, the lower curve represents the data taken
with a solid material obtained by the conventional process, i.e.
without subjecting the solid material to the inventive step
(W).
[0102] By contrast, starting from the left, the upper line shows
the respective data obtained from a solid material that has been
subjected to the inventive step (W), but otherwise has been
prepared the same way as the (non-inventive) material represented
by the lower curve. It can be clearly seen that between
approximately 200 nm and approximately 350 nm a pronounced hump in
the UV/VIS absorbance appears. This pronounced hump is not observed
for a solid material that has not been subjected to the inventive
step (W).
[0103] Overall, the inventive solid material is characterized by an
additional hump or increase in the UV/VIS absorbance in the range
between approximately 200 and approximately 350 nm, particularly in
the range from 250 to 350 nm.
[0104] 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.
[0105] If the solid material as described above has been subjected
to the inventive treatment (W), the shaped body obtained from that
solid material does not have to be subjected to the inventive
treatment (W). However, if the solid material has not been
subjected from the inventive step (W), the shaped body as obtained
by any of the steps (S) mentioned above, has to be subjected to a
inventive step (W), consisting in this case of bringing the shaped
body in contact with a composition containing water.
[0106] 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
may be 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.
EXAMPLES
Example 1
[0107] Inventive Treatment (W) of a Solid Material
[0108] 100 g of a calcined titanium zeolite spray granulate
(content with respect to titanium 1.5% by weight) are charged into
a steel autoclave that can be stirred. The titanium zeolite
granulate is stirred together with 1080 g of deionized water at 300
rpm. The duration of the treatment is 24 hours and the temperature
is 175.degree. C. After the treatment has been finished, the
content of the autoclave is filtered over a nutsch filter and is
rinsed three times with a total amount of 1500 ml of deionized
water.
[0109] The filter cake is dried for four hours at 120.degree. C.
under air atmosphere. Finally, the mass is calcined for three hours
at 550.degree. C. The final yield is 90 g and the material displays
a content in titanium of 1.5 weight %.
Example 2
[0110] Shaping of the Inventive Material from Example 1
[0111] 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.
[0112] 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.
[0113] 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.
[0114] 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. The pore volume as obtained by mercury porosimetry
(DIN 66133) is 0.84 ml/g.
Example 3
[0115] Oxidation Using the Inventive Shaped Body
[0116] 13.5 g of the catalyst described in Example 2 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/hour of
propylene (96% by volume of propylene). Temperatures were regulated
between 20 and 40.degree. C.
[0117] The analysis of the product mixture emerging from the
reactor results in that after 96 hours, the selectivity for
propylene oxide (with respect to H.sub.2O.sub.2) was 96.4%. After
416 hours a selectivity of 96% was measured. The formation of
oxygen (selectivity with respect to H.sub.2O.sub.2)was measured to
be 0.6% after 96 hours and 0.6% even after 416 hours.
Comparative Example
[0118] Using a catalyst that has not been subjected to the
inventive treatment (W) given in Example 1, the following values
have been obtained for the selectivity (under otherwise equal
conditions): after 90 hours the selectivity of propylene oxide
(with respect to H.sub.2O.sub.2) was 96.5%. After 427 hours a
selectivity of only 91.3% was measured. The formation of oxygen
(selectivity with respect to H.sub.2O.sub.2) was measured to be
0.6% after 90 hours but already 1.3% after 427 hours.
* * * * *