DE1244147B - Process for the production of unsaturated aldehydes and unsaturated carboxylic acids - Google Patents

Description

C 07C <f5 / 34

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

C07C

German class:

Number:
File number:
Registration date:
Display day:

C07c

1.2 ο-7/03

J. 244147

G42584IVb / 12ü
January 19, 1965
July 13, 1967

The invention relates to a process for the preparation of unsaturated and unsaturated aldehydes Carboxylic acids of the formula

Process for the production of unsaturated
Aldehydes and unsaturated carboxylic acids

^ ¹¹ O - t_.

in which R is a hydrogen atom or a methyl group and X represents a hydrogen atom or a hydroxyl group by gas phase catalytic oxidation of Propylene or isobutylene with oxygen-containing gases, characterized in that the oxidation is in the presence a catalyst is carried out, the

a) cobalt or nickel molybdates, a mixture of nickel molybdate and MoO ₃ , a mixture of nickel oxide and MoO ₃ , a copper phosphate, • pyrophosphate or polyphosphate,

b) TeO ₂ or, in the case of the presence of nickel molybdate, TeO ₂ or nickel tellurite and

c) HReO ₁ or Re ₂ O ₇

contains, the catalyst components when using a cobalt-containing catalyst in the ratio of about 800 mol CoMoO ₄ to 15 to 300 mol TeO ₂ to 1 to 10 mol HReO ₄ or its equivalent as Re ₂ O ₁ , when using a nickel-containing catalyst in the ratio of about 800 mol MoO _a to 160 to 800 mol NiO to 25 to 375 mol TeO ₂ to 1 to 6 mol HReO ₄ or its equivalent as Re ₂ O ₇ or when using a copper-containing catalyst in the ratio of about 100 mol of a copper phosphate to 10 to 30MoI TeO ₂ to 1 to 10 mol HReO ₄ or its equivalent are present _{as ReO 7.}

The catalytic conversion of propylene or isobutylene into acrolein or its mixtures with Acrylic acid or in methacrolein or its mixtures with methacrylic acid is known. The known Process have, inter alia, the disadvantage that the catalysts either have insufficient selectivity for the formation of the desired product or the conversion of hydrocarbons per pass into the unsaturated oxygen-containing product proportionately is low so that recycling of the unreacted hydrocarbon is required, or the Reaction conditions cannot be adjusted so that the desired product mixture is obtained will. Belgian patent 623 214 describes that 68% propylene per pass implemented if a nickel molybdate TeOj applicant:

The B. F. Goodrich Company,

Akron, Ohio (V. St. A.)

Representative:

Dr.-Ing. A. ν. Kreisler, Dr.-Ing. K. Schönwald,

Dr.-Ing. Th. Meyer,

Dipl.-Chem. Dr. rer. nat. J. F. Fues,

Patent attorneys, Cologne 1, Deichmannhaus

Named as inventor:

Dr. Jamal Shahab Eden, Akron, Ohio (V. St. A.): Dr. Charles Edgar Ziegler, Therwil (Switzerland)

Claimed priority:

V. St. v. America January 20, 1964
(338 571),

dated January 27, 1964
(340 506),

dated January 27, 1964
(340 543)

Catalyst is used at a reaction temperature of 367 ° C. Under these conditions, the yield of acrylic acid 25% and the yield of acrolein 7.5 ° / _0th The overall efficiency is therefore only about 22.1 ° / ₀ .

US Pat. No. 2,662,921 discloses a catalyst for the oxidation of propylene to acrolein, which mainly consists of TeO _{2 in} addition to small amounts of rhenium oxide. With this catalyst, however, only a maximum conversion of propylene to acrolein of 10.3 ° / ₀ is reached.

Since the combination of nickel molybdate-TeO ₂ known from Belgian patent specification 623 214 and the combination TcO ₂ -rhenium oxide known from US Pat from 32.2 to more than 70 ° / ₀

709 610,544

I 244 147

3 4

given at a conversion of the hydrocarbon used .. A solution of 80 g of concentrated from 68 to 100 ° / oP ^ro passage can be achieved. NH ₄ OH in 80 g of water was added dropwise to the addition of the mixture of cobalt (II) nitrate and ammonium molybdenum and / or the catalyst composition by adjusting the reaction conditions. After the addition, the composition of the mixture was stirred for another 30 minutes. The suspension was filtered and washed with hydrated products within a fairly further 1500 cm of water. The solids were boundaries to control. It is thus possible to re-suspend high levels twice in water and extract unsaturated aldehydes or to filter high levels. The solids were obtained each time after the unsaturated acid boil. Filtration washed with 1500 cm ^{3 of} water. To the

The copper phosphate TeO ₂ rhenium catalyst is io cobalt molybdate, different amounts of particularly effective for the production of methacro TeO ₂ and HReO ₄ in the form of fine powder were given from isobutylene. and distributed as evenly as possible by stirring. the

Amount of TeO ₂ and HReO "is different depending on

Reactants the desired ratio in the finished catalyst

15 from CoMoO ₄ to TeO ₂ to HReO ₄ or R ₂ O ₇ . To the

As a source of acid are relatively suitable production of a catalyst with CoMoO ₄ , TeO ₃ pure oxygen, air or mixtures of oxygen and HReO ₁ in a molar ratio of 800: 30: 1 with nitrogen containing more than 21% oxygen. the required amount of TeO _{2 is} 3.2 g and the amount of oxygen can also be diluted with inert gases such as neon, perrhenic acid or its equivalent as krypton, xenon or helium. 20 aminonium salt 0.250 g. In this phase the

Propylene or isobutylene is used as the olefin. Catalyst the form of a paste. The paste is used in the pure form. The olefins do not have to be dried in a vacuum oven at 80 ° C. They can contain substantial amounts of saturated alkanes or other hydrocarbons that are then fired ^{in an oven at 400 ° C. for 16 hours.} The catalyst is then used without disturbing the reaction. 25 desired grain size ground. For fixed bed systems

For hydrocarbons such as ethane, ethylene and propane, a sieve size of 0.84 to 2.00 ram is suitable. For or butane, are, not to any significant extent, fluidized bed systems that operate at normal pressure or something oxidizes and can therefore work as a diluent over it, are particles that make a sieve of a be used. They consume however a part mesh size of 177 μ but pass through one of the oxygen, so that its amount to achieve 30 sieves with a mesh size of 44 μ are retained, the best results must be adjusted regardless of the type of catalyst, most adherent.

Since some of the propylene or isobutylene will be converted to CO according to the most convenient method

and CO _{2 is} oxidized, it is very advantageous to prepare a supported catalyst as follows: A solution of the cobalt (II) salt in water is prepared in a stoichiometric excess of 30 to 100%, and oxygen is used in the reaction. Prefers ammonium molybdate in water and dissolves ammonium in an excess of about 66 mole percent. The tellurite in HNO ₃ solution, while the pH value of the maximum amount of oxygen cannot be determined, the latter is kept at 4 to 6, and produces a solution of HReO ₄ in water, but the mixture of olefin and oxygen must. The cobalt (II) compound that it is under the reaction salt is added to the molybdate solution. Then the conditions are not explosive. Tellurite solution and the solution of perrhenic acid

Water vapor is not an essential ingredient for added. Silica gel or the reaction is then added to the suspension, but the yields of diatomaceous earth or another carrier of the desired aldehydes and acids for any given particle size appear to improve the evacuated temperature and, at the same time, to improve the even distribution of the carrier to act as a heat-absorbing medium, which is stirred with and then filtered, washed and, for example, contributes to temperature control of the reaction. 16 hours at 400 ⁰ C is fired.

The reaction components can be any soluble or insoluble tellurite in proportion to the

from 1 to 3 moles of oxygen to 0 to 7 moles of steam are used during the catalyst preparation in TcO ₂ around per mole of said olefin. 50 can be converted is suitable. Likewise, everyone can

Rhenium compound can be used, which is in

The catalysts and their production Re ₂ O ₇ can be converted.

The preferred catalysts of this type are

The constituents of the cobalt-containing catalysts are those containing about 800 moles of cobalt molybdate, 20 to are used in the following proportions: 55 30 mol of tellurium dioxide and 1 to 2 mol of perrhenic acid

contain.

CoMoO ₄ 800 Mol rjj _e constituents of the nickel-containing catalysts

TeO ₂ 15 to 300 moles are used in the following proportions:

HReO ₄ or its equi- _{MoO 800 Mo} ,

valent as R ₂ O ₇ 1 b, s 10 Mo ₁ * ^. 160 to 800 moles

lMol (291g) Co (NOa) ₃ 6 H ₂ O were in 300 g HRcO ₁ or its equiva-

Dissolved in water. A solution of 177 g (NH ₄ ) _? Mo ₇ 0 ₂ 4 < lent as Rc ₂ O ₇ 1 to 6 mol

4 H ₂ O (1 molar equivalent) was obtained by heating and TeO _{2 from} 25 to 375 mol

Stir in 200 cm ^{3 of} water and then 65

Chilling made. The following composition is preferred: 800 mol

The solution of cobalt (II) nitrate was under molybdenum oxide, 670 to 750 moles of nickel oxide, 50 to

constant stirring to the ammonium molybdate solution 200 moles of TeO ₂ and 1 to 2 moles of R ₂ O ₇ .

The nickel-containing catalysts can take one of the following forms:

1. Mixture of the oxides of Ni, Mo, Te and HReO ₄ or Re ₂ O ₇ or

2. NiMoO ₄ containing TeO ₂ or nickel tellurite and HReO ₄ or Re ₂ O ₇ , or

3. a mixture of NiMoO ₄ , MoO ₃ , TeO ₃ and HReO ₄ or Re ₂ O ₇ .

To produce a catalyst of the type defined above under 1, it is only necessary to mix the ingredients well.

Catalysts of the type described under 2. are z. B. prepared as follows: Dissolve 101.79 g Ni (NOj) ₂ · 6H ₂ O in 100 cm ³ of water by heating to about 50 ⁰ C and 74.17 g of ammonium molybdate dissolved in 100 cm ³ of water at about 50 ⁰ C. Add the ammonium molybdate solution to the nickel nitrate. 4.2 g of tellurium dioxide are dissolved in 8 cm ^{3 of} concentrated HCl and the solution is added to the mixture. Then concentrated NH ₄ OH is added dropwise until the mixture is neutral. After addition of an aqueous solution of perrhenic acid or ammonium perrhenate is mixed well and evaporated in hot air at 80 to 90 ⁰ C to dryness. The dried catalyst to burn for about 16 hours at 400 ⁰ C. The rhenium compounds can of the remaining ingredients are added prior to drying of a paste as Perrhem'umsäure, ammonium or Re ₂ O. ₇ After firing, the catalyst is crushed and sieved.

For the preparation of catalysts which contain less than equivalent amounts of nickel (ie catalysts which contain a mixture of nickel molybdate and MoO ₃ ), the nickel salts are to be used in amounts below the equivalent amounts.

For the preparation of catalysts containing colloidal silica as a support, one can use the add the latter to the aqueous catalyst mixture before drying or vice versa. Then will the catalyst is treated in the manner described above.

When a porous material in the form of microspheres is used as the carrier, e.g. B. silica gel with a surface area of about 325 m ² / g, it is advisable to first _{treat the silica with concentrated NH 4} OH, filter it until the material is fairly dry, then suspend the silica in water and dissolve the Add ammonium molybdate and nickel nitrate, the tellurium and rhenium compounds in portions before neutralization, while vacuum is applied to the mixture of ingredients in order to fill all the spaces in the silica gel with the catalyst. After all the constituents have been mixed, the supported catalyst is dried, calcined, crushed and sieved.

It is also possible to make the catalyst by first making a paste with the molybdate and nickel components and then mixing in the TeO ₂ and HRcO ₄ well.

The components of the copper-containing catalysts are used in the following proportions: 100 mol of copper phosphate, LO to 30 Mo] TeO ₂ and 1 to 10 mol of HReO ₄ or its equivalent as Re ₂ O ₇ .

The copper-containing catalysts are mixtures of a copper phosphate, such as Cu ₂ (POj) ₃ , Cu ₈ P ₂ O ₇ , or a copper polyphosphate, such as Cu ₅ (P ₃ O ₁₀ ) ₂ , with tellurium dioxide and perrhenic acid or Re ₂ O ₇ .

The catalysts can be supported as or unsupported catalysts in various ways getting produced. One of these methods is described below:

34.1 g of CuCl ₂ · 2 H ₂ O was dissolved in water.
1.6 g of TeO ₂ were added to the CuCl ₂ solution.

A solution from
Ig HReO ₄ in water became CuCl ₂ -TeO ₂ -

Mixture given.

23.3 g of 85% H ₃ PO ₄ were added to the mixture of the above ingredients.

Then 247.8 g of a dispersion of microspheroidal colloidal silica in water containing 30 to 35 percent by weight SiO ₂ were added to the remaining ingredients. After stirring well, the mixture was brought to dryness on the steam bath.

ao steamed and then burned ^{at 400 0 C for about 16 hours.} If necessary, drying can be carried out by spraying. The catalyst was then cooled, crushed and sieved to the desired sizes.

In another method of preparation, the TeO ₂ was dissolved in concentrated HCl to form a homogeneous mixture before the H ₃ PO _{4 was added.} Otherwise, the working steps were the same as those described above for the preparation of the copper-containing catalyst.

In another procedure, dry, finely divided Cu ₂ P ₂ O ₇ , TeO ₂ and Re ₂ O _{7 are} mixed and ground to the desired fineness in a ball mill and sieved. If a carrier is desired, it can be added to the ball mill with the remaining ingredients.

According to another method, a paste of Cu ₂ P ₂ O ₇ or another copper phosphate is first made, after which dry TcO ₂ and Re ₂ O ₇ or HReO _{4 are added} in the required amounts. The carrier can be mixed with the paste and then dried and fired as described above.

Finely divided refractory materials of low porosity are preferably used as supports. as Carriers are materials based on silicon dioxide, e.g. B. colloidal silica, kieselguhr, clay, Diatomaceous earth, also aluminum oxide, aluminum phosphate, zirconium oxide and silicon carbide. Preferred Colloidal silica, diatomaceous earth and a mixture of aluminum oxide and silicon dioxide are used as carriers.

Reaction conditions

The reaction is carried out at a temperature of about 300 to 50O ⁰ C. The temperature depends in part on the catalysts used, in part on the oxidized olefin and in part on the type of oxygen-containing product desired. For example, for the CoMoO ₄ -TcO ₂ -HReO ₄ - and Ni-MoO ₃ -TcO ₂ -HReO ₄ catalysts, the effective temperatures for the oxidation of propylene in the range 300-425 ⁰ C, with the range 350-425 ⁰ C is most advantageous.

For copper phosphate TeO ₂ -HReO ₄ catalysts is the best temperature range for the oxidation of propylene 420 to 480 ° C and for the oxidation of isobutylene 330-450 ⁰ C. For this reason, be

these temperature ranges are preferred for the copper-containing catalysts.

The contact time can range from about 2 to about 70 seconds, but one is preferred Contact time of about 5 to 40 seconds. The most advantageous contact time depends in part on the circumstances of the reaction components, partly from the olefin to be converted, partly from the reaction temperature and partly from the catalyst used away. ίο

Air, pure oxygen or a mixture of oxygen and inert gas can be used as the oxygen-containing gas be used. The reaction can be carried out in the presence of steam.

The reaction pressure is not critically important. It can be between reduced pressure and about 3.5 kg / cm ² .

The contact time in all experiments in the fluidized bed is the hot contact time in contrast to that Cold contact time, which is specified for all fixed-bed tests.

A cold contact time of 20 seconds corresponds to a hot contact time of around 8 seconds.

B e i s ρ i e 1 1

A number of experiments were carried out in a fixed bed reactor made up of a tube There was a high-silica glass 28 cm long and 22 mm outside diameter and three inlet openings contained, namely one for air, one for propylene and one for water vapor. The reactor was with three provided electrical heating coils, one of which covers the entire outer surface of the reactor and each others could only heat about half the length of the reactor. The exit vapors were through a Gas chromatograph passed for continuous analysis of the outlet gases.

The catalyst (60 cm ³ ), which contained CoMoO ₄ , TeO ₄ and HReO ₄ in a molar ratio of 800: 20.1, took up about 90 ° / _{0 of} the reactor volume. The gases were preheated before entering the reactor at about 25O ⁰ C.

The ratio of air to propylene was adjusted so that an excess of about 66 ° / "over the stoichiometric amount required to convert propylene and acrylic acid was present. To the The reactor was supplied with steam in an amount of 1 to 4 moles per mole of propylene.

The results given in Table I show that good conversions of propylene per pass can be achieved at temperatures around 320 ⁰ C, that the ratio of acrolein to acrylic acid can be controlled by regulating the contact time or the temperature or both variables and that at a temperature of 350 ⁰ C about 50 ° / ₀ or more of desired products can be obtained with extremely high propylene conversions. They also show that extremely small amounts of the rhenium compound in the catalyst have a strong influence on the conversion and on the temperature at which the conversion is carried out.

Table I.

Oo excess H ₂ OC ₃ H ₆ -
relationship Contact time . AS = acrylic acid. temperature QHc sales yield
Mole percent
QH, AS Efficiency
Mole percent AS V Seconds ⁰ C 7o Acr. 32.6 Acr. 22.1 66 4th 20th 320 67.9 55.7 56.7 37.8 53.3 66 4th 20th 350 94.1 25.9 62.7 24.4 62.1 66 4th 28 350 99.0 11.0 60.5 11.0 60.5 66 4th 38 350 100 5.9 55.7 5.9 55.7 66 1 35 350 100 4.3 4.3 Acr. = Acrolein

For comparison, according to the Belgian Patent are given 587,683 contained best results, although a catalyst which CoMoO ₄ and TeO _2, but not containing rhenium, a conversion of 42 ° / ₀ propylene and yields of acrolein of 12% and to acrylic acid of 58%, based on the propylene converted ^{at 450 ° C.} The efficiency for acrolein formation is about 5% and for acrylic acid formation about 24% with an overall efficiency of 29% compared to a minimum efficiency of about 59.9%, which is calculated from the values in the table. In the process of Belgian patent 623 214, in which a CoMoO _r catalyst containing TeO _{2 is} used and the oxidation is carried out at 0.55 atmospheres, a propylene conversion of 81% with a 36% yield of acrylic acid and a 14% igen yield of acrolein indicated. The overall efficiency is 40.5% at a temperature of 433 ⁰ C.

Example 2

In order to determine the influence of water vapor, the following series of ^{tests were carried out at 350 °} C. with the catalyst described in Example 1. In all cases the oxygen excess was 66%, based on the propylene used.

Contact time
Seconds Table II Yield,
Acr. Mole percent
AS Efficiency
Acr. i, mole percent
AS Water - propylene -
relationship 28
35
37
25th Propylene urasat
Mole percent 10.2
9.5
22.3
32.5 58.4
57.8
45.6
39.3 9.8
9.5
10.2
26.8 56.1
57.5
44.6
32.4 4th
1
0
0 96.1
99.6
97.9
82.7

10

These values show that water is beneficial, but not essential, for obtaining good yields of acrolein and acrylic acid with the catalyst. Without the use of water, the yields are on Acrolein a little higher.

Example 3

This series of experiments was carried out with a catalyst which contained CoMoO ₄ , TeO ₂ and HReO ₄ in a molar ratio of 800: 15: 1. The S values obtained are shown in Table III below.

H ₈ OC ₃ H, -
relationship Contact time
Seconds Tabel III the end
MoIp
Acr. prey
percent
AS Effect
Molpi
Acr. gserad
ocent
AS CV excess
% 4th
4th
4th 28
28
20th temperature
⁰ C Propylene conversion
■ · / · 21.5
8.3
10.8 44.0
43.2
52.0 16.9
8.0
9.0 35.0
41.0
43.5 66
66
33 330
350
390 79.5
95.3
83.5

Example 4
The catalyst for these experiments was made to the 800: 30: 1. The contact time was 20 seconds in each case. The reaction temperature and the oxygen-propylene ratio were changed. the

The above-described manner using the results obtained in these experiments are compiled according to CoMoO ₄ —TeO ₂ —HReO ₄ in the ratio of standing.

Table IV

temperature O ₄ excess HjO propylene Propylene conversion yield
Mole percent Acr. AS Efficiency
'. Mole percent AS ⁰ C % relationship Mole percent 32.5 29.0 Acr. 28.4 380 33 4th 85.4 15.9 49.5 27.7 49.5 400 66 4th 100 19.9 40.2 15.9 38.7 400 66 4th 96.4 6.0 51.2 19.2 51.2 400 66 4th 99.8 1.7 39.6 6.0 39.6 410 100 4th 100.0 49.0 32.0 1.7 21.7 340 0 4th 67.8 33.2

When using this catalyst, the ratio of the end products obtained can be changed by changing the temperature or the level of excess oxygen can be varied considerably.

Example 5

The catalyst for these experiments contained cobalt molybdate, tellurium dioxide and HReO ₄ in a molar ratio of 800: 300: 10. All experiments were carried out with an oxygen excess of 66%, 4 moles of water per mole of propylene and a contact time of 20 seconds. The results of the tests are shown below.

Table V

Propylene
sales Yield in AS Efficiency
Mole percent AS Tempe
rature Mole percent,
related aiii
implemented 19.3 16.4 Mole percent Propylene 31.1 Acr. 29.6 ⁰ C 85.2 Acr. 27.6 63.7 26.3 385 95.2 74.8 16.1 55.0 16.1 405 95.4 57.8 48.8 420 100 51.2 26.5 445 26.5

These values show that with this catalyst at temperatures up to 445 ° C. the yields of acrolein and acrylic acid and the efficiency decrease. Analysis showed that the formation of oxides of carbon significantly increased when the temperature was increased from 420 to 445 ⁰ C. It was also found that with the high proportions of TeO _2, the ratio of acrolein to acrylic acid is considerably higher than when the TeO ₂ content is 20 to 30 mol per 800 mol of CoMoO ₄ .

Example6

A supported catalyst was prepared as follows: 349.5 g of cobalt (II) nitrate were dissolved in 21% concentrated NH ₁ OH. 212.9 g of ammonium molybdate were added to this solution; Then 8.6 g of tellurous acid and 0.377 g of HRcO _{4 were} separately dissolved in water and the mixture of cobalt (II) nitrate and

Ammonium molybdate added. ■

Microspheroidal silica (144.0 g) with a

A surface of about 350 m / g was added to 600 cm ^{3 of} concentrated ammonium hydroxide. The mixture was held at 65 ° C for 3 hours. The silica was filtered and allowed to air dry.

The silica was placed in a flask, followed by part of the solution containing the remaining ingredients contained, was added. The flask was evacuated to cover the spaces with the silica Filling in the catalytic converter. The process was started after adding the remaining mixture of cobalt nitrate, Ammonium molybdate, telluric acid, andperhenic acid are repeated.

The whole mixture was then placed in a beaker and dried on the water bath. The catalyst was then dried for 4 hours in an oven with forced ventilation at 9O ⁰ C. It was then ^{burned at 400 °} C. for 48 hours, comminuted and sieved. This catalyst

709 610/544

contained 80OMoI CoMoO ₄ , 30MoI TeO ₂ , 1 mol HReO ₄ and 400 mol SiO ₂ .

40 g of catalyst with a screen size of 0.84 to 2.00 mm were placed in the reactor. In each case, oxygen in excess of 66 ° / ₉ and 4 moles of water vapor per mole of propylene were used. The cold contact time was 13 seconds. The results of the tests are shown below.

Propylene
sales
Mole percent Tabel VI Wirkui
Molp
Acr. igsgtad
percent
AS Tempe
rature
⁰ C 84.3
94.3
97.8 Foreign
Molp
Acr. Teut
percent
AS 21.0
15.0
14.5 48.0
52.3
40.2 355
380
400 25.0
16.0
14.8 57.0
55.5
41.1

12th

When using colloidal silica in aqueous suspension as the carrier, the catalyst produced by the preferred method by precipitating the constituents on the silica particles.

Example 7

In these experiments, the catalyst contained ίο 800 moles of cobalt molybdate, 30 moles of TeO ₂ and 10 moles of HReO ₄ . It was produced in the manner described above and also used with a screen size of 0.84 to 2.00 mm. In all experiments, oxygen in excess of 66 ° / ₀ and 4 moles of water per mole of propylene were added to the reactor. The data for these experiments are summarized below.

Table VII

Contact time
Seconds temperature
⁰ C Propylene conversion
MoJ percent Acr. yield
Mole percent
I AS λ
Acr. Virku
Molp degree
percent
AS 20th
20th
38 370
400
350 92.8
100
94 56.3
26.2
53.8 52.2
26.2
50.6 29.1
38.5
29.9 31.4
38.5
31.8

Example 8

The table below shows the results obtained with a catalyst containing 800 mol of cobalt molybdate, 60 mol of TeO ₂ and 2 mol of HReO ₄ . The feed contained oxygen in excess of 66% and 4 moles of water vapor per mole of propylene. The contact time was 20 seconds.

Table VIII

temperature

⁰ C

355
375
400

Propylene conversion
Mole percent

57.6
77.0
87.0

yield

Mole percent

Acr. I AS

88.0
72.0
51.0

9.5

23.4
32.2

Efficiency

Mole percent

Acr. I AS

50.7
55.4
44.4

5.5
18.0
21.8

In all of the above examples, air was used as the source of oxygen. Comparable results however, are readily obtained when technically pure oxygen or oxygen-enriched Air can be used. Furthermore, all of the experiments described above were carried out in fixed bed reactors carried out.

To carry out the process in the fluidized bed, a catalyst must be used which has a different particle size than the catalyst used in the fixed bed system (0.84 to 2.00 mm). Of the Catalyst was therefore ground finer and the portion that a sieve with a mesh size of 177 μ. passed, but was retained by a sieve with a mesh size of 44 μ, used for the experiments. In the case of fluidized bed systems, it is also advisable to use a catalyst with the lowest possible density, especially supported catalysts to be used.

Example 9

In this series of tests, 133 g of a catalyst which contained 800 mol of CoMoO ₄ , 30MoI of TeO ₂ and 1 mol of HReO ₄ were introduced into the reactor. The catalyst took a height of about 18 cm. Air was preheated to a temperature just below the reaction temperature and introduced into the reactor at a pressure just sufficient to achieve good fluidization of the catalyst. The reactor part was also heated electrically to a temperature which was just below the temperature desired for the reaction. The water was passed through an evaporator, mixed with the air and the mixture passed through the heater where its temperature was raised to the desired value. Propylene was introduced into the heated stream of air and steam and the whole mixture was introduced into the reactor from below. The volume of the air, the steam and the propylene is dosed by measuring devices so that the ratio of reaction components and diluents can be adjusted to the desired value. The temperature measurements in the reactor parts are made with thermostats. The product leaving the reactor is passed through a water-cooled condenser, and the vapors from the condenser are passed through two dry ice traps, where all vapors of the organic compounds formed in the reaction are condensed. The uncondensed gases are passed through a gas meter, where their volume is measured, and then through a vapor phase chromatograph, where their composition is determined. The results of these tests are summarized below.

H ₂ O / C ₃ H _e

Contact time, seconds *

Temperature, ° C

C ₃ H _e urea rate, mole percent

Yield, mol percent, based on converted C ₃ H _e

Acrolein

Acrylic acid

Efficiency, mole percent

Acrolein

Acrylic acid

• = hot contact time.

2.4
4.80
8.4
350
97.6

16.2
53.1

15.8
51.8

2.71
4.58
8.4
300
56.7

47.9
41.5

27.2
23.5

2.44 5.44 7.3 350
96.4

8.5 56.6

8.3 54.8

2.65 4.66 8.2 350 89.5

14.4 52.8

12.9 47.3

The condensed liquids are also analyzed for their composition.

Example 10

This series of experiments was carried out in a fluidized bed with a catalyst on colloidal silica containing a small amount of sodium. The catalyst contained 800 moles of CoMoO ₄ , 30 moles of TeO ₂ and 1 mole of HReO ₄ and 800 moles of silica. The amount of catalyst was 260 g. At rest, this amount assumed a height of 30 cm in the reactor. The test conditions and results are summarized in the following table.

Table X Table XI

Ois / C ₃ H _e 2.57 2.77

H ₂ O / C ₃ H, 4.17 4.32

Contact time, seconds 9.0 9.1

Temperature, ⁰ C 350 375

C ₃ H ₄ conversion, mole percent 67.7 78.3

Yield, mole percent based on converted C ₃ H ₄

Acrolein 41.4 29.1

Acrylic acid 37.5 37.5

Efficiency, mole percent

Acrolein 28.0 22.8

Acrylic acid 25.4 29.4

Example 11

The following experiments were carried out in a fluidized bed with a supported catalyst which _{contained 800 mol of CoMoO 4} , 30 mol of TeO ₂ , 1 mol of HReO ₄ and a total of 800 mol of silica.

The silica support was prepared by adding 690 mol of microspheroidal silica gel with a surface area of about 350 m ^a / g to an aqueous suspension of colloidal silica containing silica in an amount corresponding to _{160 mol of SiO 2.} The mixture of the two silicas was stirred well, added to an aqueous paste of the remaining ingredients and mixed in by stirring for half an hour, after which it was dried, calcined, crushed and classified. It took 177 g to fill the reactor to a height of 30 cm at rest. The results obtained in these experiments are summarized below.

₂₅ O ₂ / C ₃ H,

H _a O / C ₃ H _e

Contact time, seconds

Temperature, ⁰ C

C ₈ H ₄ - rate, mole percent

Yield, mol percent, based on converted C ₃ H,

Acrolein,

Acrylic acid

Efficiency, mole percent

Acrolein

Acrylic acid

2.68 3.98 8.8 350 80.0

32.8 44.9

26.2 35.9

2.62 3.62 8.6 375 88.3

20; 5

43.7

18.1 38.6

If microspheroidal silica is used alone as the carrier, the catalyst must be produced by precipitation of the CoMoO ₄ on the silica particles in order to fill the surface as much as possible. The tellurium compound and the rhenium compound can be added to the enclosed silica prior to drying and firing.

B e i s ρ i e 1 12

The catalyst used in this experiment contained 670 mol NiO, 800 mol MoO ₃ , 50 mol TeO ₈ and 1 mol HReO ₄ . It was produced by dissolving the required amounts of ammonium molybdate and nickel (II) nitrate ^{separately in water at 50 °} C. and adding the ammonium molybdate solution to the nickel nitrate solution. A solution of the required amount of tellurium dioxide in a small amount of concentrated HCl is added at 50 ^° C. to the solution of the nickel and molybdenum salts; the aqueous solution does not contain any precipitation in this phase. The mixture is then _{neutralized with concentrated NH 4} OH, a precipitate separating out. After adding the required amount of ammonium perrhenate, the mixture is carefully mixed, dried and ^{fired at 400 °} C. for 16 hours. The finished catalyst was crushed and on a sieve fraction

sieved from 0.84 to 2.00 mm for fixed bed tests and 44 to 177 μ for fluidized bed tests.

About 60 cm ^{3 of} the catalyst were placed in the fixed bed reactor described in Example 1. The gaseous product emerging from the reactor was passed through a drying tube and then through a vapor phase chromatograph for continuous analysis of the reaction products.

Before entering the reactor the feed gases are preheated to a temperature of about 120 to 200 ⁰ C. The feed contained air in an amount corresponding to 2.5 moles of oxygen per mole of propylene and 4 moles of water vapor per mole of propylene. The cold contact time was calculated to be 18 seconds.

At a temperature of 390 ⁰ C 83.3 ° / ₀ of propylene were reacted. The acrolein yield was 37% and the acrylic acid yield 39.7%. The efficiencies were 30.8 and 33.1 ° / _0th At 400 ° C the propylene conversion was 87.6%, the yield of acrolein 26.8% and the yield of acrylic acid 49.7 ° / _0th The efficiencies were 23.5 and 43.5 »/ ο-

Another catalyst, which contained 800 moles of NiO, 800 moles of MoO ₃ , 50 moles of TeO ₂ and 1 mole of HReO ₄ , was used with the same ratio of reactants and with the same contact time in the fluidized bed.

temperature
⁰ C Propylene
υ rasatz
% Acrolein
ausbcute
% Acrylic acid
yield
% 380
405 78.9
88.8 69.9
54.1 1.8.1
25.5

Example 13

ίο

A catalyst was prepared by dissolving 176.6 g of Mo ₇ O ₂₄ · 4H ₂ O in 400 cm ^{3 of} water, dissolving 191.93 g of Ni (NO ₃ ) ₂ and dissolving 89.37 g of NiSO ₄ · 6H ₈ O in 400 cm ^{3 of} water, addition of the nickel salt solution to the molybdate solution and neutralization with ammonia. The precipitate was then nitrated and washed by resuspending in water until the wash water was only a faint green color. Tellurium dioxide and Re ₂ O ₇ were added to the paste in such amounts that catalysts were obtained which contained 400 mol NiO, 400 mol MoO ₃ , 25 mol TeO ₃ and 1 mol HReO ₄ or 500 mol NiO, 500 mol MoO ₃ , 25 Contained moles of TeO ₂ and 1 mole of HReO ₄ .

60 cm * of each catalyst was placed in the plague bed

a5 reactor given. The proportions of the reaction components were the same as in the previous example. The contact time was 18 seconds.

catalyst temperature
° c Propylene conversion
· /. ■ Acrolein yield
⁰ A. Acrylic acid yield
% Ni: Mo: Te: Re 400: 400: 25: 1 355 77.93 63.4 25.7 375 93.1 54.5 31.9 Ni: Mo: Te: Re 500: 500: 25: 1 .. 360 89.5 36.2 41.9 370 94.3 24.5 47.65 Ni: Mo: Te: Re 660: 660: 80: 1 340 72.9 34.1 24.4 Ni: Mo: Te: Re 800: 800: 40: 1 330 50 33.8 22.5

This example illustrates that when small amounts of rhenium are used, the reaction at lower temperatures with good propylene conversions and good yields of acrolein and acrylic acid runs.

The following experiment illustrates the results obtained in a fluidized bed reactor with an unsupported catalyst. A tube made of high-silica glass with an inner surface area of 9.08 cm ² and a length of 1.5 inches served as the reactor. The reactor was heated from the outside with an electrical heating resistor. Devices were provided for preheating the reaction components. A plate-shaped glass frit was provided at the bottom of the reactor in order to prevent the catalyst from penetrating into the outlet openings of the reactants. In these experiments, the catalyst was whirled up with hot air or a mixture of hot air and steam. The reactor temperature was set to a value which was 30 to 50 ° C. below the desired oxidation temperature of the propylene. Propylene was then introduced into the reactor and the reaction was allowed to proceed at the desired temperature. In all cases the gases entering the reactor were heated to about 250-300 ° C before coming into contact with the catalyst.

Oxygen-containing gas (air) was diluted with superheated steam prior to mixing with propylene. The feed mixture contained 1.5 moles of oxygen and 4.2 moles of water vapor per mole of propylene. The hot contact time was 17.6 seconds and the temperature 325 ° C. The catalyst contained 660 mol NiO, 800 mol MoO ₃ , 50 mol TeO ₂ and 1 mol HReO ₄ .

It was made in the manner described in Example 12.

89% of the propylene was converted under these reaction conditions. The yield of acrolein was 13.9%, the yield of acrylic acid was 36.1% and the efficiency was 12.4 and 32.1%, respectively.

B e i s ρ i e 1 14

40 cm ^{3 of} a catalyst prepared by method 1 for copper-containing catalysts with 50 moles of Cu ₂ P _? O ₇ , 5 moles of TeO ₂ and 2 moles of HReO ₁ to 620 moles of colloidal silica were placed in the reactor described in Example 1. The reactor was heated to about 280 to 300 ⁰ C, followed by steam at a temperature of about 25O ⁰ C inserted through an opening in the reactor. The required amount of propylene was mixed with the steam immediately before entering the reactor. Oxygen (supplied as air) in the required amount was introduced into the reactor through a separate inlet opening.

The reactor was then heated to the temperature indicated in the table. The contact time is

it is the cold contact time. The hot contact time is about 40% of the cold contact time mentioned.
The gases emerging from the reactor were passed through a phase chromatograph and analyzed. The condensed liquids were weighed, evaporated and passed through a vapor phase chromatograph for analysis. The ones with the different

passed through a capacitor. The results obtained without condensation are shown below ized gases were put together immediately by a steam.

Oj / C.H. H1O / C.H « Contact time temperature C, H «conversion Acrolein yield Efficiency Seconds ⁰ C Mole percent Mole percent Mole percent 1.1 4.4 10.8 420 45.3 71.7 32.5 1.1 4.4 18.9 425 45.3 71.3 32.2 1.5 4.4 9.1 470 54.7 65.5 35.8 2.0 3.4 9.1 480 66.1 68.4 45.2 2.1 5.1 18.3 430 75.6 60.7 45.9 2.1 4.3 9.3 430 80.4 55.6 44.7

Example 15

The catalyst consisted of 50 mol Cu ₂ P ₃ O ₇ , 5MoI TeO ₈ and 2MoI HReO ₄ on 620MoI SiO ₂ . The reaction mixture consisted of 1.1 moles of oxygen, which was supplied as air, and 4.4 moles of water vapor per mole of propylene. The reaction was carried out at 425 ° C. in the reactor described above. The cold contact time was 18.85 seconds. The propylene conversion was 48.7% and the acrolein yield was 69.9%, corresponding to an efficiency of 34.0 / ₀ . _{Example 6}

A number of experiments were carried out using different ratios of the catalyst components were used and the ratio of oxygen to propylene and of water vapor to Propylene was changed. The reaction conditions for each experiment and the results are as follows Table compiled.

Catalyst (mole) TeO ₈ HReO ₄ SiO, Contact time O ₄ ZC ₃ H, H ₂ O / C, H, Tempe
rature Propylene
sales Acrolein
yield Effects
ff rad Cu _s P ₈ O, 15th 1 310 Seconds ⁰ C Mole percent Mole percent 50 20th 1 1240 10.5 2.5 4.5 420 86.3 67.8 58.5 100 15th 1 620 11 1.1 4.3 445 76.5 70.1 53.6 50 10 1 620 12.5 2.5 3.6 420 61.4 83.0 51.0 50 5 2 620 9.3 2.1 4.3 440 70.6 72.6 51.2 50 5 1 620 18.3 2.1 5.1 430 75.6 60.7 45.9 50 10 1 1240 14th 2.2 4.5 435 67.4 63.5 42.8 100 30th 1 1240 9.6 2.1 3.7 460 55.0 75.5 41.5 100 15th 1 620 9.3 1.5 4.3 450 54.9 68.6 37.7 50 15th 1 310 12.5 2.5 3.6 420 61.4 83.0 51.6 50 15th 1. 155 10.5 2.5 4.5 420 86.3 67.8 58.5 50 11.0 1.5 4.5 440 41.4 91.0 37.7

The molar ratio of the components in the catalyst is the same as that used in its preparation became. The contact time is the cold contact time.

Example 17

A fixed bed catalyst which contained 50MoI Cu _a Psj0 ₇ , 15 mol TeO ₂ and 1 mol HReO ₄ and was impregnated onto 31OMoI AlPO ₄ was used in this experiment, which was carried out in the manner described in Example 1. The O ₂ -C ₃ H _e ratio was 2: 2, the H ₂ OC ₃ H ₆ ratio 3: 5, the temperature of 450 ⁰ C and the cold contact time 14.1 seconds. Under these conditions 63.6% of the propylene were converted, acrolein being obtained in a yield of 76.1%, corresponding to an efficiency of 48.4%.

Example 18

The fixed bed catalyst for this experiment consisted of 50 mol Cu ₂ P ₂ O ₇ , 15 mol TeO ₂ , 1 mol HReO ₄ to 620 mol ZrO ₂ . The O ₂ -C ₃ H ₆ ratio was 1: 1, the H ₂ OC ₃ H ₆ ratio 4: 3, the contact time 11.2 seconds and the reaction temperature 450 ° C. This catalyst gave 53.2% Propylene implemented. The acrolein yield was 70%, corresponding to an efficiency of 37.2%.

_so B is ρ ie 1 19

The reactor described in Example 1 was ^{filled with 40 cm 3 of} a catalyst, the constituents of which, namely 50 mol Cu ₂ P ₂ O ₇ , 10 mol TeO ₂ , 1 mol HReO ₄ , were applied by impregnation to 620 mol of a microspheroidal colloidal silica as a carrier was. A feedstock containing isobutylene, oxygen (supplied as air) and water vapor in a molar ratio of 1: 2: 4.1 was passed through the fixed catalyst bed at such a rate that the cold contact time was 9.5 seconds. At 330 ° C., 93.6% of the isobutylene used were converted, methacrolein being obtained in a yield of 56.8%, corresponding to an efficiency of 53.2%.

B e i s ρ i e 1 20

The catalyst contained 50 moles of Cu ₂ P ₂ O ₇ , 15 moles of TeO ₂ , 1 mole of HReO ₄ to 310 moles of a microspherical

709 610/544

dalen colloidal silica. The feed contained isobutylene, oxygen (supplied as air) and water vapor in a molar ratio of 1: 1.5: 4.1. The speed of the insert was adjusted so that the cold contact time was 27.5 seconds. At 36O ⁰ C all of the isobutylene has been converted in use, wherein methacrolein was obtained in a yield of 58.3 ° / _0th The reactor described in Example 1 was with a

Filling of 40 cm ^{3 of} the catalyst used as a fixed bed.

Example 21

The catalyst for this series of experiments contained 50 moles of Cu _? P ₉ O ₇ , 5 moles of TeO ₂ and 2 moles of HReO ₄

620MoI SiO ₂ . The results obtained with various ratios of oxygen to isobutylene are shown below.

O _t Q / H " 4.0
4.0
4.7 Contact time
Seconds temperature
⁰ C C ₄ H _r conversion
Mole percent yield
of methacrolein
Mole percent Efficiency
Mole percent 1.0
1.3
2.0 18.6
9.0
10.4 420
440
450 76.6
50.8
88.1 56.6
70.7
49.6 43.4
35.9
43.7

Claims (6)

Patent claims: 1. Process for the preparation of unsaturated aldehydes and unsaturated carboxylic acids of formula CH ₄ = c —er ^s x in which R is a hydrogen atom or a methyl group and X represents a hydrogen atom or a hydroxyl group by gas phase catalytic oxidation of propylene or isobutylene with oxygen-containing gases, characterized in that that the oxidation is carried out in the presence of a catalyst which a) cobalt or nickel molybdates, a mixture of nickel molybdate and MoO ₃ , a mixture of nickel oxide and MoO ₃ , a copper phosphate, pyrophosphate or polyphosphate, b) TeO ₂ or, in the case of the presence of nickel molybdate, TeO ₂ or nickel teurite and c) HReO ₄ or Re ₂ O ₇ contains, the catalyst components when using a cobalt-containing catalyst in a ratio of about 800 mol CoMoO ₄ to 15 to 300 mol TeO ₂ to 1 to 10 mol HReO ₄ or its equivalent as Re ₂ O ₇ , when using a 35 40 nickel-containing catalyst in a ratio of about 800 mol MoO ₃ to 160 to 800 mol NiO to 25 to 375 mol TeO ₂ to 1 to 6 mol HReO ₄ or its equivalent as Re ₂ O ₇ or when using a copper-containing catalyst in a ratio of about 100 mol of a copper phosphate to 10 to 30 mol TeO ₂ to 1 to 10 mol of HReO ₄ or its equivalent as Re ₂ O ₇ , are present. 2. The method according to claim 1, characterized in that the oxidation in the presence of Steam is carried out. 3. The method of claim 1 or 2, characterized in that the oxidation is carried out at about 300 to 500 ⁰ C. 4. The method according to claims 1 to 3, characterized in that the oxidation at a Contact time of the gases with the catalyst is carried out from about 2 to 70 seconds. 5. Process according to Claims 1 to 4, characterized in that the oxidation of propylene or isobutylene is carried out with oxygen in a molar ratio of 1 to about 1 to 3. 6. Process according to Claims 1 to 5, characterized in that the oxidation is in the presence a catalyst applied to a silica-containing support material is carried out. Considered publications:
U.S. Patent No. 2,662,921. 709 610/544 7.67 © Bundesdruckerei Berlin