U.S. patent application number 09/478406 was filed with the patent office on 2001-07-26 for reaction and use of a solid mixed oxide composition as redox system in the said reaction.
Invention is credited to HECQUET, GERARD, PHAM, CHARLOTTE, SCHIRMANN, JEAN-PIERRE, SIMON, MICHEL.
Application Number | 20010009885 09/478406 |
Document ID | / |
Family ID | 9504239 |
Filed Date | 2001-07-26 |
United States Patent
Application |
20010009885 |
Kind Code |
A1 |
HECQUET, GERARD ; et
al. |
July 26, 2001 |
REACTION AND USE OF A SOLID MIXED OXIDE COMPOSITION AS REDOX SYSTEM
IN THE SAID REACTION
Abstract
Solid mixed oxides composition of formula (I):
Mo.sub.12V.sub.aSr.sub.bW.sub.cCu.sub.dSi.sub.eO.sub.x (I)
2.ltoreq.a.ltoreq.14, 0.1.ltoreq.B.ltoreq.6, 0.ltoreq.c.ltoreq.12,
0.ltoreq.d.ltoreq.6, 0.ltoreq.e.ltoreq.15; x is the quantity of
oxygen bonded to the other elements and depends on their oxidation
states, are used in the manufacture of acrylic acid by oxidation of
acrolein, the said solid composition reacting with acrolein
according to the redox reaction (1):
SOLID.sub.oxidized+ACROLEIN.fwdarw.SOLID.sub.reduced+ACRYLIC ACID
(1). To manufacture acrylic acid, a gaseous mixture of acrolein and
of water vapor and, if appropriate, of an inert gas is passed over
a solid composition of formula (I), to conduct the redox reaction
(1) by operating at a temperature of 200 to 500.degree. C., at a
pressure of 1.01.times.10.sup.4 to 1.01.times.10.sup.6 Pa (0.1 to
10 atmospheres), and with a residence time of 0.01 second to 90
seconds, in the absence of molecular oxygen.
Inventors: |
HECQUET, GERARD; (BETHUNE,
FR) ; SCHIRMANN, JEAN-PIERRE; (PARIS, FR) ;
SIMON, MICHEL; (SAINT-AVOLD, FR) ; PHAM,
CHARLOTTE; (SAVERNE, FR) |
Correspondence
Address: |
MILLEN, WHITE, ZELANO & BRANIGAN, P.C.
2200 CLARENDON BLVD.
SUITE 1400
ARLINGTON
VA
22201
US
|
Family ID: |
9504239 |
Appl. No.: |
09/478406 |
Filed: |
January 6, 2000 |
Current U.S.
Class: |
502/306 ;
502/113; 502/120; 502/312; 502/318; 502/321 |
Current CPC
Class: |
B01J 2523/00 20130101;
C07C 51/16 20130101; C07C 51/16 20130101; C07C 57/04 20130101; B01J
2523/00 20130101; B01J 2523/17 20130101; B01J 2523/24 20130101;
B01J 2523/55 20130101; B01J 2523/68 20130101; B01J 2523/69
20130101 |
Class at
Publication: |
502/306 ;
502/312; 502/318; 502/113; 502/120; 502/321 |
International
Class: |
B01J 023/00; B01J
023/22; B01J 023/72 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 27, 1997 |
FR |
97/02344 |
Claims
1. A process for the manufacture of acrylic acid from acrolein,
according to the redox reaction (1):
SOLID.sub.oxidized+ACROLEIN.fwdarw.SOLID.sub.r- educed+ARCYLIC ACID
(1), said process comprising passing a gaseous mixture of acrolein
and of water vapour and optionally of an inert gas over a solid
composition of formula (I): Mo.sub.12V.sub.aSr.sub.bW.sub.cC-
u.sub.dSi.sub.eO.sub.x (I) in which: a is between 1 and 14, limits
included, b is between 0.1 and 6, limits included, c is between 0
and 12, limits included, d is between 0 and 6, limits included, e
is between 0 and 15, limits included, and x is the quantity of
oxygen bonded to the other elements and depends on their oxidation
state, the said solid composition reacting with the acrolein at a
temperature of 200 to 500.degree. C., at a pressure of
1.01.times.10.sup.4 to 1.01.times.10.sup.6 Pa (0.1 to 10
atmospheres) and with a residence time of 0.01 second to 90
seconds, in the substantial absence of molecular oxygen.
2. A process according to claim 1, wherein the redox reaction (1)
is conducted at a temperature of 250 to 450.degree. C.
3. A process according to claim 1, wherein the redox reaction (1)
is conducted at a pressure of 5.05.times.10.sup.4-5.05.times.
10.sup.5 Pa (0.5-5 atmospheres).
4. A process according to claim 3, wherein the redox reaction (1)
is conducted at a pressure of 5.05.times.10.sup.4-5.05.times.
10.sup.5 Pa (0.5-5 atmospheres).
5. A process according to claim 1, wherein the redox reaction (1)
is conducted with a residence time of 0.1 second to 30 seconds.
6. A process according to claim 4, wherein the redox reaction (1)
is conducted with a residence time of 0.1 second to 30 seconds.
7. A process according to claim 1, wherein once the solid
composition is converted to the reduced state, said solid
composition is regenerated according to the reaction (2):
SOLID.sub.reduced+O2.fwdarw. Solid.sub.oxidized (2) by heating in
the presence of an excess of oxygen or of an oxygen-containing gas
at a temperature of 250 to 500.degree. C., for the time needed for
the reoxidation of the solid composition.
8. A process according to claim 7, wherein the redox reaction (1)
and the regeneration are conducted in a two-stage device comprising
a reactor and a regenerator which operate simultaneously and in
which two charges of solid composition alternate periodically.
9. A process according to claim 7, wherein the redox reaction (1)
and the regeneration are conducted in the same reactor by
alternating the reaction and regeneration periods.
10. A process according to claim 1 further comprising prior to the
reaction, introducing the solid composition into a reactor and
flushing the resultant reactor with a continuous flow of an inert
gas to remove molecular oxygen.
11. A process according to claim 10, wherein the reaction is
conducted in the absence of molecular oxygen.
12. A process according to claim 1 further comprising heating the
solid composition to 200-500.degree. C. and introducing an aqueous
solution of acrolein over the solid composition to initiate the
reaction.
13. A process according to claim 10 further comprising heating the
solid composition to 200-500.degree. C. and introducing an aqueous
solution of acrolein over the solid composition to initiate the
reaction.
14. A process according to claim 1, wherein the solid composition
is of the formula
Mo.sub.12V.sub.4.8Sr.sub.0.5W.sub.2.4Cu.sub.2.2Ox.
15. A solid mixed oxide composition of the formula
Mo.sub.12V.sub.4.8Sr.su- b.0.5W.sub.2.4Cu.sub.2.2Ox, x being the
quantity of oxygen bonded to the other elements and depending on
their oxidation states.
Description
[0001] The present invention relates to the manufacture of acrylic
acid from acrolein by oxidation according to a redox reaction. The
invention also relates to the use of a solid mixed oxides
composition as redox system for the said reaction.
[0002] Industrial production of acrylic acid is at present carried
out by vapour phase catalytic oxidation of acrolein. All attempts
to improve this process have hitherto related to the development of
catalysts giving the highest possible conversion of acrolein and
the highest possible selectivity for the desired acrylic acid.
[0003] Thus, French Patent No. 2 222 349 describes a catalyst for
the preparation of acrylic acid by vapour phase catalytic oxidation
of acrolein using a gas containing molecular oxygen, this catalyst
including a catalytic oxide on an inert porous support, this
catalytic oxide having the following metal composition:
Mo.sub.12V.sub.2-14Z.sub.0.1-6W.sub.0-12Cu.sub.0-6
[0004] Z being at least one of Be, Mg, Ca, Ba and Sr, and at least
one of W and Cu being always present.
[0005] This catalyst can be prepared by adding a support (powdered
material or .alpha.-alumina, silicon carbide or similar beads) to
an aqueous solution in which compounds of the various catalyst
elements are dissolved, evaporating the aqueous solution to dryness
to deposit the catalyst elements on the support and calcining the
dried product between 300 and 800.degree. C.
[0006] The Applicant Company has now discovered that acrylic acid
can be manufactured by gas phase oxidation of acrolein in the
absence of molecular oxygen, by passing a gaseous mixture of
acrolein and water vapour and, if appropriate, of an inert gas over
a specific solid mixed oxides composition, which acts as a redox
system and supplies the oxygen necessary for the reaction.
[0007] The advantages of this new process are the following:
[0008] the disadvantage of an oxidation with molecular oxygen is
the overoxidation promoting the degradation of the products formed;
according to the present invention, since the operation is carried
out in the absence of molecular oxygen, the formation of CO.sub.x
(carbon monoxide and carbon dioxide), degradation products, is
reduced, and this allows the selectivity for acrylic acid to be
substantially increased;
[0009] the selectivity for acrylic acid remains good when the
degree of reduction of the solid composition increases;
[0010] once it has undergone a reduction and the progressive loss
of its activity, the solid composition can be easily regenerated by
heating in the presence of oxygen or of a gas containing oxygen
after a certain period of use; after the regeneration the solid
recovers its initial activity and can be employed in a new reaction
cycle;
[0011] the separation of the stages of reduction of the solid
composition and of its regeneration makes it possible:
[0012] to increase the selectivity for acrylic acid; and
[0013] to increase the partial pressure of acrolein, such a partial
pressure of acrolein feed being no longer restricted by the
existence of an explosive region of the acrolein+oxygen
mixture.
[0014] The subject of the present invention is therefore firstly
the use of a solid mixed oxides composition of formula (I):
Mo.sub.12V.sub.aSr.sub.bW.sub.cCu.sub.dSi.sub.eO.sub.x (I)
[0015] in which:
[0016] a is between 2 and 14, limits included,
[0017] b is between 0.1 and 6, limits included,
[0018] c is between 0 and 12, limits included,
[0019] d is between 0 and 6, limits included,
[0020] e is between 0 and 15, limits included, and
[0021] x is the quantity of oxygen bonded to the other
[0022] elements and depends on their oxidation states, in the
manufacture of acrylic acid by oxidation of acrolein, the said
solid composition reacting with acrolein according to the redox
reaction (1):
SOLID.sub.oxidized+ACROLEIN.fwdarw.SOLID.sub.reduced+ACRYLIC ACID
(1).
[0023] The oxides of the various metals forming part of the
composition of the mixed oxide of formula (I) can be employed as
raw materials in the preparation of this composition, but the raw
materials are not restricted to the oxides; as other raw materials
there may be mentioned:
[0024] in the case of molybdenum: ammonium molybdate and is
molybdic acid,
[0025] in the case of vanadium: ammonium metavanadate,
[0026] in the case of strontium: strontium hydroxide, carbonate or
nitrate,
[0027] in the case of tungsten: ammonium tungstate and tungstic
acid,
[0028] in the case of copper: copper hydroxide, carbonate or
nitrate,
[0029] and, in general, any compounds capable of forming an oxide
on calcination, namely metal salts of organic acids, metal salts of
inorganic acids, complex metal compounds and organic metal
compounds, and the like.
[0030] The source of silicon generally consists of colloidal
silica.
[0031] In accordance with specific embodiments, solid compositions
of formula (I) can be prepared by mixing, with stirring, aqueous
solutions of ammonium paratung-state, ammonium metavanadate,
ammonium molybdate and copper nitrate and strontium nitrate, adding
colloidal silica if appropriate, and then drying them and calcining
them in air between 300 and 600.degree. C., preferably between 350
and 500.degree. C.
[0032] Another subject of the present invention is a process for
the manufacture of acrylic acid from acrolein, according to which
process a gaseous mixture of acrolein and of water vapour and, if
appropriate, of an inert gas such as nitrogen is passed over a
solid composition of formula (I) defined above, to conduct the
redox reaction (1) as indicated above, by operating at a
temperature of 200 to 500.degree. C., especially from 250 to
450.degree. C., at a pressure of 1.01.times.10.sup.4 to
1.01.times.10.sup.6 Pa (0.1 to 10 atmospheres), especially from
5.05.times.10.sup.4 to 5.05.times.10.sup.5 Pa (0.5-5 atmospheres)
and with a residence time of 0.01 second to 90 seconds, especially
from 0.1 second to 30 seconds, in the absence of molecular
oxygen.
[0033] The acrolein/water vapour volume ratio in the gaseous phase
is not critical and may vary within wide limits.
[0034] During the redox reaction (1), the solid composition
undergoes a reduction and a gradual loss of its activity. This is
why, once the solid composition has changed to the reduced state,
regeneration of the said solid composition is conducted according
to the reaction (2):
SOLID.sub.reduced+O.sub.2.fwdarw.SOLID.sub.oxidized (2)
[0035] by heating in the presence of an excess of oxygen or of an
oxygen-containing gas at a temperature of 250 to 500.degree. C.,
for the time needed for the reoxidation of the solid
composition.
[0036] After the regeneration, which can be carried out in
temperature and pressure conditions which are identical with or
different from those of the redox reaction, the solid composition
recovers an initial activity and can be employed in a new reaction
cycle.
[0037] The redox reaction (1) and the regeneration may be conducted
in a two-stage device, namely a reactor and a regenerator which
operate simultaneously and in which two charges of solid
composition alternate periodically; the redox reaction (1) and the
regeneration may also be conducted in the same reactor by
alternating the reaction and regeneration periods.
[0038] The preparation of acrylic acid according to the invention
takes place according to a stoichiometric and noncatalytic
reaction.
[0039] The following examples illustrate the present invention
without, however, restricting its scope. The conversions,
selectivities and yields are defined as follows: 1 Conversion ( % )
= Number of moles of acrolein which have reacted Number of moles of
acrolein introduced .times. 100 Selectivity ( % ) for acrylic acid
= Number of moles of acrylic acid formed Number of moles of
acrolein which have reacted .times. 100 Selectivity ( % ) for
acetic acid = Number of moles of acetic acid formed Number of moles
of acrolein which have reacted .times. 100
EXAMPLE 1(a)
Preparation of a Solid of Formula
Mo.sub.12V.sub.4.8Sr.sub.0.5W.sub.2.4Cu.- sub.2.2O.sub.x, x being
the quantity of oxygen bonded to the other elements and depending
on their oxidation states
[0040] 3.6 g of ammonium paratungstate, 3.0 g of ammonium
metavanadate and 12.4 g of ammonium heptamolybdate are introduced
into 100 g of water and heated to 100.degree. C. 3.0 g of copper
nitrate and 0.62 g of strontium nitrate are introduced into 5 g of
water and heated to 100.degree. C. The second solution is added to
the first and the resulting solution is then evaporated to dryness
and then calcined for 4 hours at 400.degree. C.
EXAMPLE 1(b) (Comparative):
Preparation of Acrylic Acid from Acrolein
[0041] 50 mg of a solid prepared according to Example 1(a) are
charged into a tubular reactor and the reactor is then flushed with
a continuous flow of 20 ml/minute of air and heated to 300.degree.
C. An injection of an aqueous solution of 12% by weight of
acrolein, containing 1.1.times.10.sup.-6 mol of acrolein, is
introduced onto the solid. 97% of the acrolein is converted with
selectivities for acrylic acid and for acetic acid of 56% and 4%
respectively.
EXAMPLE 2
Preparation of Acrylic Acid from Acrolein by a Redox Reaction
[0042] After the treatment of Example 1(b) the reactor is flushed
with a continuous flow of 17 ml/minute of nitrogen and heated to
300.degree. C. An injection of an aqueous solution of 12% by weight
of acrolein, containing 1.1.times.10.sup.-6 mol of acrolein, is
introduced onto the solid. 99.1% of the acrolein is converted with
selectivities for acrylic acid and for acetic acid of 65% and 6.5%
respectively.
EXAMPLE 3
[0043] After having conducted the reaction of Example 2 the same
solid is again subjected to eleven successive injections of
acrolein in the same test conditions as Example 2. The performance
values obtained are reported in Table 1. (Injection No. 1
corresponds to Example 2).
1 TABLE 1 Acrolein Selectivity Selectivity Injection conversion for
acrylic for acetic No. (%) acid (%) acid (%) 1 99.1 65 6.5 2 98.2
79 6.5 3 96.5 81 5.9 4 95.7 86 5.3 5 92.8 89 3.9 6 89.8 90 3.6 7
85.5 90 3.3 8 83.4 92 3.1 9 83.9 91 3.4 10 84.0 89 3.4 11 73.6 90
3.6 12 70.8 91 3.6
EXAMPLE 4
[0044] After the reducing treatment of Example 3 the solid is
regenerated for 2 hours at 300.degree. C. under a flow of air and
then placed back under a flow of nitrogen. Twenty-four new
successive injections of aqueous solution of 12% by weight of
acrolein, containing 1.1.times.10.sup.-6 mol of acrolein, are
introduced onto the solid.
[0045] The performance values obtained are reported in
2 TABLE 2 Acrolein Selectivity Selectivity Injection conversion for
acrylic for acetic No. (%) acid (%) acid (%) 1 99.5 61 5.3 2 90.8
79 3.8 3 97.7 84 5.3 4 94.2 90 4.0 5 93.0 88 3.8 6 91.4 89 3.5 7
83.2 91 2.9 8 82.3 90 3.0 9 82.4 90 3.3 10 78.6 90 3.4 11 71.4 91
3.6 12 68.5 89 3.8 13 67.8 90 3.7 14 62.5 90 3.7 15 61.5 89 3.7 16
58.1 90 3.8 17 56.2 92 3.8 18 54.7 91 3.7 19 54.1 91 3.7 20 49.1 92
3.9 21 47.5 92 3.9 22 49.1 92 3.7 23 47.8 93 3.7 24 42.6 94 3.9
[0046] The preceding examples can be repeated with similar success
by substituting the generically or specifically described reactants
and/or operating conditions of this invention for those used in the
preceding examples.
[0047] The entire disclosure of all applications, patents and
publications, cited above and below, and of corresponding French
application No. 97/02344, are hereby incorporated by reference.
[0048] From the foregoing description, one skilled in the art can
easily ascertain the essential characteristics of this invention,
and without departing from the spirit and scope thereof, can make
various changes and modifications of the invention to adapt it to
various usages and conditions.
[0049] As for the expression "in the substantial absence of
molecular oxygen" in the claims, it is to be understood that the
greater the removal of oxygen from the reactor prior to the
reaction, the better the selectivity to acrylic acid will be.
However, a chemical engineer will readily recognize that the extent
of removal of molecular oxygen is a cost/benefit problem. For
example, it might be very expensive to remove final traces of
molecular oxygen to obtain only a slight improvement. Thus, the
word "substantial" is intended to convey an absence of molecular
oxygen which leads to an improved result as compared to a process
where no effort is made to eliminate molecular oxygen, for example
those processes set forth in the comparative examples.
* * * * *