U.S. patent application number 10/582827 was filed with the patent office on 2007-07-19 for method for producing a catalytic preparation and use of said catalytic preparation.
Invention is credited to Elke Hirschberg, Regina Optehostert, Klaus Pipplies, Bernd Proft, Michael Wedler, Jochen Winkler.
Application Number | 20070167311 10/582827 |
Document ID | / |
Family ID | 34683591 |
Filed Date | 2007-07-19 |
United States Patent
Application |
20070167311 |
Kind Code |
A1 |
Proft; Bernd ; et
al. |
July 19, 2007 |
Method for producing a catalytic preparation and use of said
catalytic preparation
Abstract
A process is described for the production of a catalyst
preparation, in which the catalyst containing at least one
inorganic compound which is solid under standard conditions is
comminuted by means of a dispersion unit into particles having a
maximum average particle size d.sub.50.3 of 2 .mu.m, preferably a
maximum of 1 .mu.m, implemented in accordance with DIN 66141 and
DIN 66144, and is distributed at a concentration of from 1 to 50
wt. % (relative to the finished catalyst preparation) in a
liquid.
Inventors: |
Proft; Bernd;
(Neukirchen-Vluyn, DE) ; Hirschberg; Elke; (Moers,
DE) ; Optehostert; Regina; (Moers, DE) ;
Winkler; Jochen; (Rheurdt, DE) ; Pipplies; Klaus;
(Neukirschen-Vinyn, DE) ; Wedler; Michael;
(Duisburg, DE) |
Correspondence
Address: |
FULBRIGHT & JAWORSKI, LLP
666 FIFTH AVE
NEW YORK
NY
10103-3198
US
|
Family ID: |
34683591 |
Appl. No.: |
10/582827 |
Filed: |
December 9, 2004 |
PCT Filed: |
December 9, 2004 |
PCT NO: |
PCT/EP04/14026 |
371 Date: |
August 2, 2006 |
Current U.S.
Class: |
502/60 ; 502/216;
502/217; 502/300 |
Current CPC
Class: |
C09C 1/3623 20130101;
C01P 2006/12 20130101; B01J 37/0036 20130101; C01P 2004/62
20130101; C01P 2004/52 20130101; C01P 2004/61 20130101; C09C 3/041
20130101 |
Class at
Publication: |
502/060 ;
502/216; 502/217; 502/300 |
International
Class: |
B01J 27/053 20060101
B01J027/053; B01J 27/02 20060101 B01J027/02; B01J 29/04 20060101
B01J029/04 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 19, 2003 |
DE |
103 59 839.1 |
Claims
1-10. (canceled)
11. A process comprising producing a catalyst preparation by
comminuting a catalyst containing at least one inorganic compound
which is solid under standard conditions with a dispersion unit
into particles having a maximum average particle size d.sub.50.3 of
2 .mu.m, implemented in accordance with DIN 66141 and DIN 66144,
and is distributed at a concentration of from 1 to 50 wt. %,
relative to the finished catalyst preparation, in a liquid.
12. The process according to claim 11, wherein the catalyst is
distributed in a liquid at a concentration of from 20 to 40 wt %,
relative to the finished catalyst preparation.
13. The process according to claim 11, wherein the solid inorganic
compound is at least one compound selected from the group
consisting of titanium dioxide, titanium-dioxide-containing
substances, titanates, zeolites, aluminum oxide, boron oxides,
germanium dioxide, antimony(III) oxide, cerium oxides, barium
sulfate, zinc sulfide, and silicon dioxide.
14. The process according to claim 13, wherein the solid inorganic
compound is at least one compound selected from the group
consisting of hydrated titanium dioxide corresponding to the
composition yTiO.sub.2.zH.sub.2O (where y=1, z=0.01 to 2), and a
titanate corresponding to the composition
(MenO).sub.x.(TiO.sub.2).sub.y.(H.sub.2O).sub.z (where Me=Li, Na,
K, Rb, Cs, Mg, Ca, Sr, Ba; n=1 for Me=alkaline earth metal and n=2
for Me=alkali metal; x=0.0001 to 6; y=1; z=0.01 to 2).
15. The process according to claim 11, wherein the particles have a
maximum average particle size d.sub.50.3 of 1 .mu.m.
16. The process according to claim 11, wherein the following said
unit selected from the group consisting of a stirred ball mill, an
ultrasonic homogenizer, an ultrasonic disintegrator, a
high-pressure homogenizer, dispersing equipment based on the
high-power pulse-type technique, dispersing equipment based on the
impact jet process and an impact stream-type mill.
17. A process according to claim 11, wherein the liquid is at least
on liquid selected from the group consisting of water, a
C.sub.1-C.sub.20 alcohol, a diol, a carboxylic acid and a fatty
acid.
18. A method comprising performing a condensation reaction, a
polycondensation reaction, a transesterification of an ester, a
transamidation of an amide, a rearrangement or an olefin
polymerization with the catalyst preparation prepared by the
process of claim 11.
19. A method comprising performing a photocatalysis reaction with
the catalyst preparation prepared by the process of claim 11.
20. A method comprising boosting the effect of a catalyst enzyme
system with the catalyst prepared by the process of claim 11.
Description
[0001] The invention relates to a process for the production of a
catalyst preparation and the use thereof.
[0002] Solid catalysts are frequently utilised in the production of
polyesters. Such catalysts may, for example, be TiO.sub.2 or
compounds derived from TiO.sub.2. For example, EP 0736560 describes
catalysts comprising alkali metal titanate or alkaline earth metal
titanate.
[0003] In heterogeneous catalysis the catalyst is not dissolved in
the reaction medium but is present as a separate solid phase. In
one variant on this catalysis, the catalyst remains as a separate
solid phase within the system. In some cases, such as, for example,
in catalysis of esterification processes, the catalyst is added as
a powder which, however, dissolves in the course of the reaction.
Here, a continuous transition from heterogeneous to homogeneous
catalysis takes place.
[0004] The distribution of the catalyst in the reaction medium
greatly influences the course of the reaction.
[0005] It is in principle possible to supply a heterogeneous
catalyst in powder form to the reaction medium. However, in
continuous processes specifically, in addition to the disadvantage
of poor meterability of the powders, this method has deficiencies
in terms of distributing the catalyst rapidly in the reaction
medium. It is therefore prior art practice to utilise slurries of
the catalyst in liquids.
[0006] Since the catalyst particles settle readily when the
catalyst slurries are stored, such slurries must be agitated before
use, because otherwise the metering of the catalyst would in turn
not be sufficiently precise.
[0007] Stokes' law states that the rate of sedimentation .nu. is
proportional to the square of the diameters d of the catalyst
spherules and to the density difference .DELTA..rho. between solid
and liquid, and inversely proportional to the viscosity .eta. of
the suspending liquid; v = d 2 .DELTA. .times. .times. .rho. g 18
.times. .times. .eta. ( Stokes ` .times. .times. law ) ]
##EQU1##
[0008] It is apparent from the equation that over time all the
catalyst particles must settle, provided that their rate of
sedimentation is greater than their thermal (Brownian) motion.
[0009] In addition to gravity, the van der Waals force of
attraction, also known as the "dispersion force", also acts on the
particles. If not opposed by stabilising forces, for example a like
electrostatic charge, or adsorbed polymers, the dispersion force
causes flocculation to take place among the particles. If the
particles flocculate, then larger agglomerates arise which settle
all the more rapidly in accordance with Stokes' equation.
Flocculated, settled systems, on the other hand, have the advantage
that they can be agitated readily.
[0010] The opposite is the case with slurries, in which
sedimentation out of a flocculation-resistant distribution takes
place because of the size of the catalyst particles. Apart from the
disadvantage of settling to a very densely packed sediment now
barely able to be agitated, a further disadvantage of such systems
is that they generally contain undesirable auxiliary substances
(polymeric wetting and dispersing agents).
[0011] The object of the invention is to provide a process for the
production of a catalyst preparation, in which the disadvantages of
the prior art, namely in particular [0012] excessively coarse
distribution of the catalyst [0013] poor meterability of the
catalyst powder [0014] poor meterability of the catalyst when
settled slurries are used [0015] sedimentation of the catalyst to a
solid bottom sediment which cannot be agitated are avoided, and in
which the catalyst obtained is, on the one hand, sufficiently
stable in storage and, on the other, can deploy the maximum
catalytic activity.
[0016] The object is achieved by a process for the production of a
catalyst preparation, in which the catalyst, containing at least
one inorganic compound which is solid under standard conditions, is
comminuted by means of a dispersion unit into particles having a
maximum average particle size d.sub.50.3 of 2 .mu.m, preferably a
maximum of 1 .mu.m, implemented in accordance with DIN 66141 and
DIN 66144, and is distributed at a concentration of from 1 to 50
wt. %, preferably 20 to 40 wt. % (relative to the finished catalyst
preparation) in a liquid. The particle size is preferably measured
by laser diffraction.
[0017] Surprisingly, without the aid of wetting or dispersing
agents or otherwise any auxiliary substance which stabilises the
suspension, the catalyst can in this way be produced as a paste
which is solidified in the resting state. The paste does not begin
to flow until a minimum shear stress, the yield point To, is
reached.
[0018] The yield point of the catalyst paste rises as the catalyst
concentration increases and the particle size decreases,
respectively. The yield point of the catalyst paste can be adjusted
by varying the catalyst concentration and the particle size. The
catalyst paste preferably has a yield point .tau..sub.0 of at least
0.1 Pa at 23.degree. C. (room temperature), particularly preferably
1 to 30 Pa and most particularly preferably 5 to 30 Pa, at
23.degree. C. The yield point is determined in accordance with DIN
53019 in the Z2 DIN cylinder measuring system (described in the
data sheet "Data for the standard measuring system in accordance
with DIN 53019" for Viscolab/Rheolab MC 10 from Physika
Me.beta.technik GmbH, Stuttgart) and evaluation in accordance with
Bingham. For this purpose, the sample (catalyst paste) is charged
into the Z2 standard measuring system where it is first left to
rest at room temperature for a period of 24 hours. Measuring takes
place with 100 measuring points with a measuring time of 5 sec per
measuring point within the shear rate range 0 to 100 l/s (linear
ramp).
[0019] The process described guarantees that the stable catalyst
paste can be brought by agitation to a form in which it is readily
meterable and can be mixed effectively into the reaction mixture,
with the catalyst activity being put to optimal use. Here, the
catalyst is present in colloidal form and is unusually stable in
storage. Even when the suspension is stored for a year, the
catalyst does not settle and retains its full activity. It is
furthermore advantageous that the utilisation of auxiliary
substances for creating a yield point (for example polyurethane
thickeners, polyacrylate thickeners, cellulose ether, highly
disperse silica) is superfluous.
[0020] The inorganic compound which is solid under standard
conditions (catalyst or catalyst constituent) can, for example, be
selected from the following substances: titanium dioxide,
titanium-dioxide-containing substances, titanates, zeolites,
aluminium oxide, boron oxides, germanium dioxide, antimony(III)
oxide, cerium oxides, barium sulfate, zinc sulfide, silicon dioxide
or mixtures of these substances.
[0021] Titanium dioxide and the titanium-containing catalysts
described in EP 0736560: hydrated titanium dioxide corresponding to
the composition
yTiO.sub.2.zH.sub.2O (where y=1, z=0.01 to 2), or a titanate
corresponding to the composition
(MenO).sub.x.(TiO.sub.2).sub.y.(H.sub.2O).sub.z (where Me=Li, Na,
K, Rb, Cs, Mg, Ca, Sr, Ba; n=1 for Me=alkaline earth metal and n=2
for Me=alkali metal; x=0.0001 to 6; y=1; z=0.01 to 2).
are particularly preferred here.
[0022] Stirred ball mills, ultrasonic homogenizers, or ultrasonic
disintegrators, high-pressure homogenisers, dispersing equipment
based on the high-power pulse-type technique, dispersing equipment
based on the impact jet process (for example counter-jet-type
mills) or impact stream-type mills (for example microjet
dispersers) can, for example, be utilised as the dispersion unit.
Stirred ball mills are particularly preferred.
[0023] The catalyst can be pre-dispersed or formed into a slurry in
the liquid before the comminution. For this, dissolvers, stirrers
(for example straight-arm paddle agitators, cage-type agitators or
toothed-disk stirrers), Hoesch turbines or Ystral mills can be
used. The catalyst is then brought to the desired particle size in
the liquid by means of one of the dispersion units described
above.
[0024] The catalyst can also be dry-comminuted and then formed into
a slurry in the liquid in a dissolver, stirrer (for example
straight-arm paddle agitator, cage-type agitator or toothed-disk
stirrer), a turbine or an Ystral mill.
[0025] The following relationship generally applies to the choice
of particle size and catalyst concentration: The smaller the
particle size, the lower the selected catalyst concentration should
be within the limits indicated, and vice versa.
[0026] The following substances are preferably utilised
individually or in mixture as the liquid: water, alcohols having 1
to 20 C atoms (for example methanol, ethanol, propanol (all
isomers), butanol (all isomers), diols such as alkane diols or
cycloalkane diols having 2 to 12 C atoms (for example ethylene
glycol, 1,3-propanediol, 1,4-butanediol, 1,4-cyclohexane
dimethanol), carboxylic acids (for example formic acid, ethanoic
acid, propanoic acid, butanoic acid, pentanoic acid) or fatty
acids.
[0027] The process according to the invention can, for example, be
carried out as follows (with no limitations being, however,
associated therewith):
[0028] Where it is not already present in powder form, the catalyst
material is powdered in known manner, stirred into the liquid and
pre-dispersed (for example using a toothed-disk dissolver). The
suspension obtained is then treated by means of a dispersion unit
(for example a bead mill) until the average particle size
d.sub.50.3 reaches a maximum value of 2 .mu.m, preferably a maximum
of 1 .mu.m. The catalyst preparations produced according to the
invention are used, inter alia, in condensation and
polycondensation reactions (for example the amidation of carboxylic
acids, esterifications of carboxylic acids and their hydrolysis),
in transesterifications of esters, in transaaidations of amides, in
rearrangements (for example alpha-pinene into camphene, aldol
reaction) and in olefin polymerisation.
[0029] The catalyst preparation produced according to the invention
can furthermore be used in photocatalysis. Thus, for example a
TiO.sub.2-containing catalyst preparation can be introduced into a
medium which is polluted with noxious bacterial or chemical
substances, with the noxious substances being oxidised in the
presence of light. Areas for utilising such photocatalysts are
paints, lacquers, finishes, paper, wallcoverings, self-cleaning
surfaces or antibacterial surfaces.
[0030] A further possible use for the catalyst preparation is to
boost the effect of catalyst enzyme systems. For this, for example,
enzymes can be added during the production of the catalyst
preparation to the inorganic compound distributed in the liquid.
The enzymes settle out on the surface of the solid. The enzymes are
advantageously present there in distributed form and are at the
same time immobile.
[0031] The invention is explained in greater detail with reference
to the Embodiment Example which follows:
EXAMPLE 1
Production of a Stable Titanium-Containing Catalyst Preparation
[0032] 280 g of a pulverulent Ti-containing catalyst having a Ti
content of 48.1 wt. %, a specific BET surface of 71.5 m.sup.2/g and
an average particle size d.sub.50.3 of 2.7 .mu.m, which has been
produced in accordance with the method described In EP 0736560,
were stirred into 520 g monoethylene glycol by means of a
toothed-disk dissolver (diameter 4 cm, speed 1300 r.p.m.) and
dispersed for 45 minutes. The suspension thus formed was ground in
a stirred ball mill (Dispermat SL, 125 ml grinding compartment, 100
ml glass beads, diameter 1 mm) for 20 minutes at 3000 r.p.m. and 50
minutes at 4000 r.p.m. in a circulating process. The suspension was
separated from the beads and the coarse fraction by way of a sieve
(56 .mu.m mesh). The particle size determination (laser
diffraction, Helos) showed an average particle diameter d.sub.50.3
of 0.92 .mu.m with a breadth of distribution of B.sub.90/10=1.5
.mu.m. The solids content was around 35 wt. %. After three days'
storage at 80.degree. C. the suspension also showed no bottom
sediment formation. The dispersed suspension was charged into a Z2
DIN measuring system and left to stand at room temperature for 48
hours. Measurement took place with 100 measuring points with a
measuring time of 5 sec per measuring point within the shear rate
range of 0 to 100 l/s (linear ramp). The shear stress (on
commencing shear stressing) of the suspension was determined at
.tau..sub.0=22.6 Pa (measurement in accordance with DIN 53019, Z2
DIN, evaluation in accordance with Bingham).
* * * * *