Title of Invention

A PROCESS FOR THE CATALYTIC EPOXIDATION OF OLEFINS WITH HYDROGEN PEROXIDE IN A CONTINOUS FLOW REACTION SYSTEM.

Abstract The invention described herein relates to a process for the catalytic epoxidation of olefins with hydrogen peroxide in a continuous flow reaction system, wherein the reaction mixture is passed through a fixed catalyst bed in down-flow operation mode and the reaction heat is at least partially removed during the course of the reaction. (FIG.)nil
Full Text PROCESS FOR THE EPOXIDATION OF OLEFINS
Prior Art
From EP-A 100 119 it is known that propene can be converted by hydrogen
peroxide into propene oxide if a titanium-containing zeolite is used as
catalyst.
Unreacted hydrogen peroxide cannot be recovered economically from the
epoxidation reaction mixture. Furthermore, unreacted hydrogen peroxide
involves additional effort and expenditure in the working up of the
reaction mixture. The epoxidation of propene is therefore preferably
carried out with an excess of propene and up to a high hydrogen peroxide
conversion. In order to achieve a high hydrogen peroxide conversion it
is advantageous to use a continuous flow reaction system. Such a
reaction system may comprise either one or more tubular flow reactors or
an arrangement of two or more flow mixing reactors connected in series.
Examples of flow mixing reactors are stirred tank reactors, recycle
reactors, fluidized bed reactors and fixed bed reactors with recycling
of the liquid phase.
In order to achieve a high reaction rate a high propene concentration in
the liquid phase is necessary. The reaction is therefore preferably
carried out under a propene atmosphere at elevated pressure with the
effect that a multiphase reaction system is in general present.
Furthermore the epoxidation of olefins with hydroperoxides is like most
oxidation reactions highly exothermic. Thus precautions have to be taken
to ensure sufficient removal of the heat generated by the exothermic
reaction in order to control the reaction. This problem is especially
pronounced in continuos flow systems using fixed bed reactors. Moreover
conversion and product selectivity in epoxidation reactions of olefins
are highly susceptible to temperature changes with the effect that
efficient temperature control is off uppermost importance.
In A. Gianetto, "Multiphase Reactors: Types, Characteristics and Uses",
in Multiphase Chemical Reactors: Theory, Design, Scale-up, Hemisphere
Publishing Corporation, 1986 criteria governing the choice between up-
flow and down-flow fixed bed multiphase reactors are given. Advantages
of up-flow regime compared to down-flow regime are:
better mixing resulting in improved heat and mass transfer;
at the same fluid flow rates the up-flow operation provides higher
volumetric gas/liquid mass transfer coefficients;
better liquid distribution in the cross section;
better heat dissipation and more uniform temperature;
better wetting of the catalyst and therefore increased catalyst
effectiveness;
slower aging of the catalyst
avoiding compacting of the catalyst bed.
Disadvantages are:
larger pressure drops and higher energy expenditure for pumping;
reactor has to comprise means to hold the catalyst in place in
case of high velocities;
higher mass transfer resistance inside the liquid and an increase
in possible homogeneous side reactions can occur.
In view of the advantages with respect to heat transfer and dissipation
up-flow operation of a fixed bed reactor for multiphase reaction systems
is the natural choice for highly exothermic reactions where temperature
control is important.
This is also reflected in WO 97/47614 where in example 8 reaction of
propene with hydrogen peroxide using a fixed bed tubular reactor having
a cooling jacket in up-flow operation is described. But nevertheless
yield and product selectivity are still insufficient for commercial
purposes.
EP-A 659 473 describes an epoxidation process wherein a liquid mixture
of hydrogen peroxide, solvent and propene is led over a succession of
fixed bed reaction zones connected in series in down-flow operation. No
temperature control means are present within the reactor to remove the
generated heat from the single reaction zones. Thus each reaction zone
can be considered as an independent adiabatic reactor. In each reaction
zone the reaction is performed to a partial conversion, the liquid
reaction mixture is removed from each reaction zone, is led over an
external heat exchanger to extract the heat of reaction, and the major
proportion of this liquid phase is then recycled to this reaction zone
and a minor proportion of the liquid phase is passed to the next zone.
At the same time gaseous propene is fed in together with the liquid feed
stock mixture, is guided in a parallel stream to the liquid phase over
the fixed bed reaction zones, and is extracted at the end of the
reaction system in addition to the liquid reaction mixture as an oxygen-
containing waste gas stream. Although this reaction procedure enables
the propene oxide yield to be raised compared to conventional tubular
reactors without the temperature control described in EP-A 659 473. it
nevertheless involves considerable additional costs on account of the
complexity of the reaction system required to carry out the process.
From US-A 5 849 937 a process for epoxidation of propene using
hydroperoxides especially organic hydroperoxides is known. The reaction
mixture is fed to a cascade of serially connected fixed bed reactors in
down-flow regime with respect to each single reactor. Similarly to the
teaching of EP-A 659 473 in each reactor only partial conversion is
accomplished and the reactors are not equipped with heat exchange means.
Like in EP-A 659 473 the reaction heat is removed by passing the
effluent from each reactor through heat exchangers prior to introducing
the reaction mixture to the next fixed bed reactor in series thereby
adding to the complexity of the reaction system.
The disadvantages of the reaction systems as discussed in EP-A 659 473
and US-A 5 849 937 are the complexity and thus the increased costs for
investment and the high susceptibility to changes of process parameters
like flow velocity due to the adiabaticly operated independent reaction
zones and reactors respectively.
In view of the cited prior art the object of the present invention is to
provide a process for the epoxidation of olefins that results in
improved conversion and product selectivity compared to WO 97/47614
while avoiding the disadvantages of the teachings of EP-A 659 473 and
US-A 5 849 937 which can be carried out using conventional reaction
systems.
Subject of the Invention
This object is achieved by a process for the catalytic epoxidation of
olefins with hydrogen peroxide in a continuous flow reaction system,
wherein the reaction mixture is passed through a fixed catalyst bed in
down-flow operation mode and the reaction heat is at least partially
removed during the course of the reaction. The process of the present
invention is therefore preferably conducted in a fixed bed reactor
comprising cooling means.
A particularly preferred embodiment of the present invention refers to a
process for the catalytic epoxidation of propene with hydrogen peroxide
in a continuous flow reaction system conducted in a multiphase reaction
mixture comprising an liquid aqueous hydrogen peroxide rich phase
containing methanol and an liquid organic propene rich phase, wherein
the reaction mixture is passed through a fixed catalyst bed in down-flow
operation mode and the reaction heat is at least partially removed
during the course of the reaction.
The present inventors have surprisingly discovered, contrary to the
general textbook knowledge as exemplified by A. Gianetto supra, that a
cooled fixed bed reactor can be successfully operated in a down-flow
operation to increase product selectivity and thereby overall product
yield compared to an up-flow operation as previously used in the prior
art. This effect is even more surprising since it is known that the
epoxidation of olefin is a highly exothermic reaction that is difficult
to control since this reaction has a considerably high activation
temperature and therefore has to be conducted at a certain minimum
temperature to achieve economically reasonable conversion. But on the
other hand the heat generated by the exothermic reaction has to be
effectively removed from the reactor since at increased temperatures
unwanted side reactions take place with the result that product
selectivity is decreased. The effect of limited temperature increase
within the catalyst bed is discussed to some extent in EP-A-659 473.
With respect to the examples it is disclosed that in conventional
tubular reactors temperature rise in the catalyst bed exceeds 15°C
whereas according to the examples in EP-A-659 473 the temperature rise
is 8°C at the most and in the preferred embodiment 5½°C. Thus according
to the teaching of EP-A-659 473 temperature rise within the catalyst bed
has to be kept as low as possible in order to achieve high yields of
propylene oxide. This reduced temperature rise could only be achieved
according to EP-A-659 473 by conducting the reaction in a single
reaction zone to only a partial conversion with the result that the
majority of the reaction mixture has to be recycled, and by
intermediately cooling the reaction mixture.
According to the teaching of A. Gianetto et al. when operating a
conventional tubular fixed bed reactor poor heat dissipation and
nonuniform temperature within the catalyst bed has to be expected in
case of downflow operation mode. Thus it has to be expected that by
using a downflow operation mode in a conventional cooled fixed bed
reactor without intermediate external cooling of the reaction mixture a
high temperature rise within the catalyst bed due to poor heat
dissipation would occur that should dramatically decrease product
selectivity and thus the yield. But contrary to this expectation, as
will be shown in more detail below in the examples, better product
selectivity at the same conversion compared to up-flow operation mode is
achieved and similar or even better overall yields based on hydrogen
peroxide compared to the most preferred embodiments in EP-A-659 473 are
obtainable although a conventional reactor system without intermediate
external cooling was used.
Detailed Description of the Invention
In the practice of the present invention any reactor having a fixed
catalyst bed and cooling means can be used. Adiabatic reaction
conditions as taught in EP-A 659 473 and US-A 5 849 937 should be
avoided. Preferably, tubular, multi-tubular or multi-plate reactors are
used. Most preferably, tubular reactors having a cooling jacket are
applied since they are standardly available at relatively low cost. As
cooling medium that is pumped through the cooling means, preferably the
cooling jacket, all standard cooling media like oils, alcohols, liquid
salts or water can be used. Water is most preferred.
The process according to the invention for the epoxidation of olefins,
preferably propene, is typically carried out at a temperature of 30° to
80°C, preferably at 40° to 60°C. According to a preferred embodiment of
the present invention the temperature profile within the reactor is
maintained such that the cooling medium temperature of the cooling means
of the tubular reactor is at least 40°C and the maximum temperature
within the catalyst bed is 60°C at the most, preferably 55°C. By
preference the temperature of the cooling medium is controlled by a
thermostat.
The maximum temperature within the catalyst bed is measured with a
plurality of suitable temperature measurement means like thermocouples
or a Pt-100 arranged approximately along the axis of the preferably
tubular reactor in suitable distances with respect to each other.
Whereby number, position within the reactor and distances between the
temperature measurement means are adjusted to measure the temperature of
the catalyst bed within the entire reactor as exact as necessary.
The maximum temperature of the catalyst bed can be adjusted by different
means. Depending on the selected reactor type the maximum temperature of
the catalyst bed can be adjusted by controlling the flow rate of the
reaction mixture passing through the reactor, by controlling the flow
rate of the cooling medium passing through the cooling means or by
lowering the catalyst activity, for instance by diluting the catalyst
with inert material.
The flow rate of the cooling medium is preferably adjusted to keep the
temperature difference between entry of the cooling medium into the
cooling means and exit below 5°C, preferably below 3°C, most preferably
2°C.
By selecting such a narrowly defined temperature profile within the
reactor an optimized balance between hydrogen peroxide conversion and
olefin oxide selectivity can be achieved.
The pressure within the reactor is usually maintained at 5 to 50 bar
preferably 15 to 30 bar.
According to a preferred embodiment the reaction mixture is passed
through the catalyst bed with a superficial velocity from 1 to 100 m/h,
preferably 5 to 50 m/h, most preferred 5 to 30 m/h. The superficial
velocity is defined as the ratio of volume flow rate/cross section of
the catalyst bed. Consequently the superficial velocity can be varied in
a given reactor by adjusting the flow rate of the reaction mixture.
Additionally it is preferred to pass the reaction mixture through the
catalyst bed with a liquid hourly space velocity (LHSV) from 1 to 20 h-1,
preferably 1.3 to 15 h-1.
Whenever the flow rate of the reaction mixture is adjusted to fulfill
the above defined requirements for superficial velocity and liquid
hourly space velocity particularly high selectivities can be achieved.
According to particularly preferred embodiment of the present invention
the process is conducted to maintain the catalyst bed in a trickle bed
state. It has been surprisingly discovered that if the trickle bed state
is maintained under certain flow conditions the effect of the present
invention i.e. the increased propene oxide selectivity will be
particularly pronounced.
These conditions are as follows:
G/? L? wherein
G is the gaseous superficial velocity defined as the gaseous flow rate
in mVh in the continuous flow reactor divided by the cross-section of
the catalyst bed in m2,
L is the liquid superficial velocity defined as the liquid flow rate in
mVh in the continuous flow reactor divided by the cross-section of the
catalyst bed in m2,
?G is the density of the gaseous phase in g/cm3,
?L is the density of the liquid phase in g/cm3,
?W is the density of water in g/cm3.
?Alr is the density of air in g/cm3,
sw is the surface tension of water in dyn/cm.
sL is the surface tension of the liquid phase in dyn/cm.
µL is the viscosity of the liquid phase in centipoise.
µw is the viscosity of water in centipoise.
In order to be able to operate the process continuously when changing
and/or regenerating the epoxidation catalyst, two or more flow reactors
may if desired also be operated in parallel or in series in the before-
described manner.
Crystalline, titanium-containing zeolites especially those of the
composition (Ti02)x(SiO2)1-x where x is from 0.001 to 0.05 and having a MFI
or MEL crystalline structure, known as titanium silicalite-1 and
titanium silicalite-2, are suitable as catalysts for the epoxidation
process according to the invention. Such catalysts may be produced for
example according to the process described in US-A 4.410.501. The
titanium silicalite catalyst may be employed as a shaped catalyst in the
form of granules, extrudates or shaped bodies. For the forming process
the catalyst may contain 1 to 99% of a binder or carrier material, all
binders and carrier materials being suitable that do not react with
hydrogen peroxide or with the epoxide under the reaction conditions
employed for the epoxielation. Extrudates with a diameter of 1 to 5 mm
are preferably used as fixed bed catalysts.
When practicing the present invention it is preferred that the overall
feed stream to the reactor comprises an aqueous hydrogen peroxide
solution, an olefin and an organic solvent. Thereby these components may
be introduced into the reactor as independent feeds or one or more of
these feeds are mixed prior to introduction into the reactor.
Using the process according to the invention any olefins can be
epoxidized in particular olefins with 2 to 6 carbon atoms. The process
according to the invention is most particularly suitable for the
epoxidation of propene to propene oxide. For economic reasons it would
be preferred for an industrial scale process to use propene not in a
pure form but as a technical mixture with propane that as a rule
contains 1 to 15 vol.% of propane. Propene may be fed as a liquid as
well as in gaseous form into the reaction system.
The hydrogen peroxide is used in the process according to the invention
in the form of an aqueous solution with a hydrogen peroxide content of 1
to 90 wt.%, preferably 10 to 70 wt.% and particularly preferably 30 to
50 wt.%. The hydrogen peroxide may be used in the form of the
commercially available, stabilised solutions. Also suitable are
unstabilised, aqueous hydrogen peroxide solutions such as are obtained
in the anthraquinone process for producing hydrogen peroxide.
The reaction is preferably carried out in the presence of a solvent in
order to increase the solubility of the olefin, preferably propene, in
the liquid phase. Suitable as solvent are all solvents that are not
oxidised or are oxidised only to a slight extent by hydrogen peroxide
under the chosen reaction conditions, and that dissolve in an amount of
more than 10 wt.% in water. Preferred are solvents that are completely
miscible with water. Suitable solvents include alcohols such as
methanol, ethanol or tert. butanol; glycols such as for example ethylene
glycol, 1,2-propanediol or 1,3-propanediol; cyclic ethers such as for
example tetrahydrofuran, dioxane or propylene oxide; glycol ethers such
as for example ethylene glycol monomethyl ether, ethylene glycol
monoethyl ether, ethylene glycol monobutyl ether or propylene glycol
monomethyl ether, and ketones such as for example acetone or 2-butanone.
Methanol is particularly preferably used as solvent.
The olefin is preferably employed in excess relative to the hydrogen
peroxide in order to achieve a significant consumption of hydrogen
peroxide, the molar ratio of olefin, preferably propene, to hydrogen
peroxide preferably being chosen in the range from 1.1 to 30. The
solvent is preferably added in a weight ratio of 0.5 to 20 relative to
the amount of hydrogen peroxide solution used. The amount of catalyst
employed may be varied within wide limits and is preferably chosen so
that a hydrogen peroxide consumption of more than 90% preferably more
than 95%, is achieved within 1 minute to 5 hours under the employed
reaction conditions.
According to one embodiment of the resent invention reaction conditions
like temperature, pressure, selection of olefin and selection of solvent
and relative amounts of the components of the reaction mixture are
chosen to ensure the presence of only one aqueous liquid phase wherein
the olefin is dissolved. An additional gaseous olefin containing phase
may also be present.
But it is preferred to conduct the epoxidation of olefins with hydrogen
peroxide in a multiphase reaction mixture comprising an liquid aqueous
hydrogen peroxide rich phase containing an organic solvent having a
solubility in water of at least 10% by weight at 25°C and an liquid
organic olefin rich phase. Thereby an even better product selectivity
can be achieved.
As is appreciable by any person skilled in the art the presence of two
immiscible liquid phases in a reaction system comprising an olefin, an
water miscible organic solvent and an aqueous hydrogen peroxide solution
will depend on many different factors. First of all the presence of an
additional olefin rich liquid organic phase will depend on the
temperature and pressure applied in the reactor and the selected olefin.
Preferably the applied pressure is at or above the vapor pressure of
the olefin at the chosen temperature. Furthermore it will depend on the
selection of the organic solvent. Suitable as organic solvent are all
solvents that dissolve in an amount of more than 10 wt.% in water at
25°C. Preferred are solvents that dissolve in an amount of more than 30
wt.% in water at 25°C preferably more than 50 wt.% in water at 25°C. The
most preferred solvents are completely miscible with water. In principle
all solvents as exemplified above can also be used in this preferred
embodiment as long as the conditions are met to ensure the presence of
two liquid phases.
Additionally the presence of a second organic olefin rich phase will
depend on the relative amounts of olefin, water and solvent. The amount
of solvent is chosen to achieve sufficient solubility of the olefin in
the hydrogen peroxide rich aqueous phase in order to get the desired
rate of reaction. At a given temperature , pressure, olefin and solvent
the relative amounts of ingredients can be adjusted to ensure formation
of a second liquid organic phase. I.e. to ensure the formation of a
second liquid organic olefin rich phase the amount of olefin has to be
selected in excess of the amount soluble in the aqueous phase at the
chosen temperature and pressure.
A simple means of experimentally confirming the presence of a second
liquid organic phase at the reaction conditions is by collecting a
sample of the reaction mixture in a container equipped with a sight
glass at the temperature and pressure used in the process.
Alternatively, the reactor may be equipped with a sight glass at a
suitable position to observe the phase boundary directly during the
reaction. In case of a continuous flow reactor the sight glass is
preferably positioned near the outlet of the reactor effluent to have an
optimal control that two liquid phases are present through out the
entire residence time within the reactor.
Thus a person skilled in the art can without any effort verify whether
when applying certain selections for olefins, solvents and reaction
parameters a two-liquid phase system as required by the present
invention is present and can adjust by variation of the parameters as
discussed above in detail the reaction system in order to establish a
second liquid organic phase.
According to a most preferred embodiment of the present invention the
olefin is selected to be propene, and methanol is used as a solvent. For
example for a reaction mixture comprising propene, methanol, and aqueous
hydrogen peroxide at a reaction temperature between 30°C and 80°C, a
pressure from 5 to 50 bar the ratio of propene flow to total flow in
case of a continuous flow system can be adjusted to be in the range of
0.1 to 1, preferably 0.2 to 1 in order to obtain a second liquid organic
phase.
An additional gas phase comprising olefin vapor and optionally an inert
gas i.e. a gas that does not interfere with the epoxidation can be
additionally present according to the present invention. Adding an inert
gas is useful to maintain a constant pressure inside the reactor and to
remove oxygen gas formed by the decomposition of a small part of the
hydrogen peroxide charged to the reactor.
The present invention will be explained in more detail referring to the
following examples:
Examples 1 and 2 and Comparative Examples 1-4
A titanium-silicate catalyst was employed in all examples. The titanium-
silicate powder was shaped into 2 mm extrudates using a silica sol as
binder in accordance with example 5 in EP 00 106 671.1. The H202 employed
was prepared according to the anthraquinone process as a 40 wt-% aqueous
solution.
Epoxidation is carried out continuously in a reaction tube of 300 ml
volume, a diameter of 10 mm and a length of 4 m. The equipment is
furthermore comprised of three containers for liquids and relevant pumps
and a liquid separating vessel. The three containers for liquids
comprised methanol, the 40% H202 and propene. The 40% H202 was adjusted
with ammonia to a pH of 4.5. The reaction temperature is controlled via
an aqueous cooling liquid circulating in a cooling jacket whereby the
cooling liquid temperature is controlled by a thermostat. The reactor
pressure was 25 bar absolute. Mass flow of the feeding pumps was
adjusted to result in a propene feed concentration of 21.5 wt-%, a
methanol feed concentration of 57 wt-% and an H202 feed concentration of
9.4 wt-%.
When performing the examples and comparative examples flow mode
(downflow (DF) mode or upflow (UF) mode) as well as the cooling jacket
temperature and the total mass flow were varied as indicated in Table 1.
The flow rate was adjusted to achieve comparable conversions. The
product stream was analyzed by gas chromatography and the H202 conversion
was determined by titration. Propene selectivity was calculated as the
ratio of the amount of propene oxide relative to the total amount of
propene oxide and oxygen containing hydrocarbons formed during the
epoxidation reaction such as 1-methoxy-2-propanol, 2-methoxy-l-propanol
and 1,2-propanediol.
Table 1:
When comparing CE1 and CE2 with CE3 and CE4 it is evident that product
selectivity strongly depends on the reaction temperature with decreasing
selectivity with increasing temperature. Thus good heat dissipation and
uniform temperature is important. In this respect a person skilled in
the art would prefer the up-flow mode. Surprisingly, as can be seen from
comparing E1 and CE2 the results in down-flow mode are even better at
the same reaction temperature.
UF - up-flow mode
DF = down-flow mode
WE CLAIM:
1. A process for the catalytic epoxidation of olefins with
hydrogen peroxide in a continuous flow reaction system? wherein
the reaction mixture is passed through a fixed catalyst bed in
down-flow operation mode wherein a fixed bed reactor comprising
cooling means is used and the reaction heat is at least partially
removed during the course of the reaction, the reaction
temperature being from 30 to 80ºC? and the reactor being
maintained at 5 to 50 bar.
2. The process as claimed in claim 1 wherein the fixed bed
reactor is a tubular reactor and the cooling means is a cooling
jacket.
3. The process as claimed in any of the preceding claims,
wherein the reaction mixture is passed through the catalyst bed
with a superficial velocity from 1 to 100 m/h? preferably 5 to 50
m/h. most preferably 5 to 30 m/h.
4. The process as claimed in any of the preceding claims,
wherein the reaction mixture is passed through the catalyst bed
with a liquid hourly space velocity (LHSV) from 1 to 20 h-1
preferably 1.3 to 15 h-1.
5. The process as claimed in any of the preceding claims,
wherein the fixed catalyst bed is maintained in a trickle bed
state.
6. The process as claimed in claim 5, wherein trickle bed
state is maintained under following flow conditions:
G/? L? wherein
G is the gaseous superficial velocity defined as the gaseous flow
rate in m3/h in the continuous flow reaction system divided by
the cross-section of the catalyst bed in m2.
L is the liquid superficial velocity defined as the liquid flow
rate in m3/h in the continuous flow reaction system divided by
the cross-section of the catalyst bed in m2.
PG is the density of the gaseous phase in g/cm3.
PL is the density of the liquid phase in g/cm3
Pw is the density of water in g/cm3
PAir is the density of air in g/cm3,
sw is the surface tension of water in dyn/cm.
sL is the surface tension of the liquid phase in dyn/cm,
µL is the viscosity of the liquid phase in
centipoise,
mw is the viscosity of water in centipoise.
7. The process as claimed in any of the preceding claims,
wherein the reaction temperature is preferably from 40 to 60ºC.
8. The process as claimed in claim 7, wherein a temperature
profile within the reactor in maintained such that the cooling
medium temperature of the cooling means is at least 40ºC and the
maximum temperature within the catalyst bed is 60ºC at the most.
9. The process as claimed in any of the preceding claims,
wherein the pressure within the reactor is maintained preferably
at 15 to 30 bar.
10. The process as claimed in any of the preceding claims,
wherein the overall feed stream to the reactor comprises an
aqueous hydrogen peroxide solution, an olefin and an organic
solvent.
11. The process as claimed in claim 10, wherein the reaction
is conducted in a multiphase reaction mixture comprising a
liquid aqueous hydrogen peroxide rich phase containing an organic
solvent having a solubility in water of at least 10% by weight at
25ºC and a liquid organic olefin rich phase.
12. The process as claimed in any of the claims 10 and 11
wherein the organic solvent is metahnol.
13. The process as claimed in any of the preceding claims,
wherein a titanium- containing zeolite is used as catalyst.
14. The process as claimed in any of the preceding claims,
wherein the olefin is propene.
15. A process for the catalytic epoxidation of propene with
hydrogen peroxide in a continuous flow reaction system conducted
in a multiphase reaction mixture comprising a liquid aqueous
hydrogen peroxide rich phase containing methanol and a liquid
organic propene rich phase, wherein the reaction mixture is
passed through a fixed catalyst bed in down-flow operation mode
and the reaction heat is at least partially removed during the
course of the reaction.
A process for the catalytic epoxidation of olefins with
hydrogen peroxide in a continuous flow reaction system, wherein
the reaction mixture is passed through a fixed catalyst bed in
down-flow operation mode wherein a fixed bed reactor comprising
cooling means is used and the reaction heat is at least partially
removed during the course of the reaction, the reaction
temperature being from 30 to 80ºC, and the reactor being
maintained at 5 to 50 bar.

Documents:

1129-kolnp-2003-granted-abstract.pdf

1129-kolnp-2003-granted-claims.pdf

1129-kolnp-2003-granted-correspondence.pdf

1129-kolnp-2003-granted-description (complete).pdf

1129-kolnp-2003-granted-examination report.pdf

1129-kolnp-2003-granted-form 1.pdf

1129-kolnp-2003-granted-form 18.pdf

1129-kolnp-2003-granted-form 2.pdf

1129-kolnp-2003-granted-form 3.pdf

1129-kolnp-2003-granted-form 5.pdf

1129-kolnp-2003-granted-gpa.pdf

1129-kolnp-2003-granted-letter patent.pdf

1129-kolnp-2003-granted-reply to examination report.pdf

1129-kolnp-2003-granted-specification.pdf


Patent Number 213956
Indian Patent Application Number 01129/KOLNP/2003
PG Journal Number 04/2008
Publication Date 25-Jan-2008
Grant Date 23-Jan-2008
Date of Filing 05-Sep-2003
Name of Patentee DEGUSSA AG.
Applicant Address 40474 DUSSELDORF GERMANY
Inventors:
# Inventor's Name Inventor's Address
1 HAAS, THOMAS 60322, FRANKFURT GERMANY
2 HOFEN WILLI SUDRING 54,63517 RODENBACH GERMANY
3 SAUER JORG, VON-DEM-BUSCHE-STRASSE GERMANY
4 THIELE GEORG JULIUS-LEBER-STRASSE GERMANY
PCT International Classification Number B22D 13/06
PCT International Application Number PCT/EP02/02288
PCT International Filing date 2002-03-04
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 01105248.7 2001-03-05 Germany