DE1197441B - Process for the production of acrolein - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

C 07c

German KL: 12 ο - 7/03

Number: 1197441

File number: E 23392IV V12 ο

Filing date: August 17, 1962

Opening day: July 29, 1965

The invention relates to a process for the production of acrolein by oxidizing propylene with Oxygen or gases containing oxygen at elevated temperature in the presence of a solid, Molybdenum and bismuth containing catalyst.

It is known (see British patent specification 821 909 and French patent specification 1 272 358), to use catalysts for the production of unsaturated aldehydes and ketones from α-monoolefins, which contain bismuth and molybdenum. The "> known catalysts are made by reaction Made from bismuth salts with molybdic acid or phosphomolybdic acid and represent bismuth molybdates or bismuth phosphorus molybdates. The known catalysts develop their greatest activity in * 5 Presence of water vapor. The amounts of catalyst required to carry out the known process are relatively large, the yields of process products, based on the amounts of catalyst used, however small.

It is also known e.g. B. from German Auslegeschrift 1 079 615, in the production of acrolein by oxidation of propylene with oxygen as catalysts, oxygen acids of the elements boron, Phosphorus, chromium, molybdenum, tungsten or vanadium with metals of atomic numbers 25 to 30 too use. However, the degrees of conversion that can be achieved in this known process are not especially high.

Process for the production of acrolein

Applicant:

Eastman Kodak Company, Rochester, N.Y.

(V. St. A.) Representative:

Dr.-Ing. W. Wolff and H. Bartels, patent attorneys, Stuttgart 1, Lange Str.

Named as inventor:

Edgar Lamar McDaniel,

Howard Seth Young, Kingsport, Term.

(V. St. A.)

Claimed priority:

V. St. v. America August 21, 1961 (132 556)

Gases at elevated temperature in the presence of a solid catalyst containing molybdenum and bismuth. It is characterized in that the oxidation at temperatures of 300 to 600 ⁰ C in counter-In other known methods are Kataly- a catalyst consisting of a mixture used, the most essential component of bismuth oxide and a heteropolyacid of copper or a copper connection exists. formula

These processes have the disadvantage that satisfactory [Ce (Mo O)]

Low yields can only be obtained if the

olefin to be oxidized is carried out in a large excess, 35, the proportion of both based on the oxygen used for the oxidation, catalyst constituents in the mixture 3 to each is used. As a result, the concentration is 75 percent by weight.

Tration of reaction products into the reactor The used for the production of the catalysts

leaving gases is relatively small and that large volumes of heteropolyacid can be produced from its ammonium salt have to be circulated by gases. 40 can be made. The manufacture of ammonium der The invention was therefore based on the object, a dodecamolybdenum is known. For the production To develop a process for the production of acrolein, the salt can, for example, a solution of 600 g that does not have the disadvantages of the known processes ammonium heptamorybdate tetrahydrate ^ OOOmlWas. In particular, a continuous water should be heated to the boil, whereupon during a A feasible procedure can be developed which is carried out in a period of 30 minutes with vigorous stirring The presence of a catalyst is carried out, which is a solution of 100 g of cerium ammonium nitrate in 1000 ml is thermally very stable, which is added dropwise through saturated carbon water. When adding the cerium hydrogens is not adversely affected, easy solution falls a canary-yellow, crystalline low-regeneration and remains highly active for a long time. knock out. After the cerium salt solution completely The invention relates to a method for 50 has been added, the precipitate and Production of acrolein by oxidation of the solution to cool for about 15 hours or stand-propylene left with oxygen or containing oxygen, whereupon the precipitate with the surviving

509 628/392

3 4

Slurried the liquid again, then 2 minutes. The oxygen can also be diluted with other dilutions is allowed to settle and average the cloudy liquid, such as. B. carbon dioxide, or inert gases, is decanted. The yellow crystalline precipitate, like argon, may be dilute.

is then decanted three times with 500 ml. The method of the invention is carried out at temperatures

Washed water, filtered and air getrock- 5 of 300 to 600 ⁰ C, particularly 350 to about 500 ⁰ C, net. The salt decomposes at least partially when carried out. Since the reaction is not particularly dependent on the high pressure applied to the preparation of the catalysts, the process can be carried out both at atmospheric temperatures to the acid. Sphere pressure, at pressures less than one

The preparation of the catalyst mixture used in the process of the invention is carried out at atmospheric pressure or at overpressure, is carried out in the manner known as the gas space velocity, which defines a mixture of bismuth oxide and heteropoly acid as the number of volumes of the feed gas or ammonium salt of the heteropoly acid under normal conditions , which are passed per hour through an elevated temperature, for example 450 to 600 ⁰ C, 1 volume of the catalyst mixture, is calcined for several hours. Instead of can also be chosen very differently. Bismuth oxide can also be used with another bismuth compound.

be used. Suitable bismuth compounds The catalyst mixture can both in the form of a

For example, bismuth oxide, bismuth carbonate, solid bed and a fluidized bed are used Bismuth hydroxide, bismuth nitrate, bismuth oxalate, bismuth. Working in a fluidized bed reactor is mother oxide, bismuth pentoxide and bismuth oxysulphate. particularly useful because the temperature of the Metallic bismuth can also be used, since the strongly exothermic reaction that takes place is easy to use can be controlled at least in part during the calcination.

oxidized with the formation of bismuth oxide. The proportion of the catalyst mixture can be used as such or on

of bismuth oxide and heteropolyacid in the catalyst are used, deposited on an inert carrier, Sator mixture is in each case 3 to 75%, preferably The use of a carrier has proven to be particularly 10 to about 59% based on the weight of the proven beneficial. Suitable supports consist of a catalyst mixture. for example made of silicon dioxide, pumice stone, kieselguhr,

The titanium dioxide, aluminum oxide, magnesium oxide, Mi catalysts used in the process of the invention maintain their activity for a long time, are 30 loops made of silicon dioxide and aluminum oxide, thermally stable and can be treated with magnesium oxide, zirconium oxide, thorium oxide, clays with a gas containing molecular oxygen and silica gel.

easily regenerated. These catalysts have to be used to carry out the process of the invention

the further advantage that they are very suitable for one after the usual for the implementation of the fluidized bed principle working process are suitable. 35 known catalytic reactions in the gas phase The catalysts also have the property that devices such as tubular Resie not, like many other known oxidation catalysts, which are continuous or discontinuous generators, which may be carried along in propylene, can be operated and are constructed in such a way saturated hydrocarbons are inactivated. Hence, the feed gas with the catalyst in can e.g. B. a larger amounts of propane containing 40 intimate contact can come. The ones from the reactor Propylene can be used as the starting material, gases are converted into suitable cooling and escaping without the conversion of the propylene in acrolein separation devices and carried out in a known manner and the yield of acrolein adversely affected separately. For example, those from the reactor will. Also, no significant leaking gases with cold water or a Amounts of formaldehyde obtained, which is when many 45 other suitable solvents are brought into contact known high-temperature oxidation processes to wash out the reaction products. In Hydrocarbons is the case. In such a case, acrolein can be washed out as well

It has been found that the two catalyst can be isolated by distillation. That is not reversed the propylene added in the process of the invention can be fed back into the system applied catalyst mixture, used on its own, 50. Any catalyst consumed are ineffective. can normally be caused by heating in contact with air

According to the method of the invention, acrolein will be reactivated wisely under reaction conditions produced from propylene according to the following equation: For those described in the following examples

rvt - m rw -i_ η _> _ γη - rw mn _ι_ w η experiments, a fluidized bed reactor was made difficult

55 fusible glass is used. The reactor passed

Here, with the theoretical molar ratio, a cylinder with a conical bottom can be used. The ratio of propylene to oxygen is 1: 1. The reactor had a height of 25 cm and an inner diameter. However, molar ratios of propylene diameter of 4 cm in the lower part and a throughput to oxygen of 1: 0.05 to about 1:10 diameter of 5.5 cm in the upper part can also be used. The loading will. Optionally, the reaction can also be carried out in the presence of water in the presence of water. That and created a fluidized bed. The heating water acts as a diluent. The reactor can be done electrically,
in amounts from about 0.05 to about 2 moles per mole of the gases and vapors exiting the reactor

Propylene can be added. Since there was no nitrogen, traps were cooled with a dry ice bath Exerting influence on the reaction can be introduced as an oxidizing 65. The condensate obtained almost passed Means instead of oxygen also uses air made entirely from acrolein and water. They don't will. If air is used, the ratio of condensable gases should be through a valve from oxygen to nitrogen are approximately 1: 4. derived from a flow meter. In particular

At intervals, samples were taken from the gas flow and the traps removed from the cooling bath and thawed. The condensate was then diluted with water. The traps were washed with water. The entire aqueous solution was then analyzed. The gas samples contained im generally about 80% nitrogen, while the remainder of 20% practically consists of propylene, oxygen, carbon dioxide and carbon monoxide.

Below is the average contact time Understand time during which the reactants under reaction conditions in one Linger volume corresponding to that of the catalyst bed.

The rate of formation of acrolein results from the so-called space-time yield, i.e. H. the Number of grams of acrolein that are formed per liter of catalyst in one hour (abbreviated g / l / hour).

The percentage conversion of propylene into acrolein results from the equation:

Number of moles of acrolein formed Number of moles of propylene consumed

100.

Comparative example

The superiority of the catalysts used in the process of the invention over catalysts, made by reacting bismuth salts with molybdic acid or phosphomolybdic acid and which are referred to as bismuth molybdates or bismuth phosphorus molybdates results from the following comparative example. Propylene was once with a catalyst according to the invention

o dung and, on the other hand, converted to acrolein with a catalyst according to British patent specification 821 999. The experiments were carried out in the fluidized bed reactor described. The temperature was 430 ° C. The following were introduced into the reactor per minute:

168 cm ³ propylene,

938 cm ³ air,

503 cm ^{3 of} water vapor.

All extra information contained in the following table relates to acrolein. The abbreviation KG / EM means catalyst weight in the reactor / reaction mixture fed into the reactor per minute in cubic centimeters.

KG / EM 100

Method of the invention

Degree of conversion
in ° / o

Yield in%

Space-time yield

British Patent Procedure

Degree of conversion
in %

yield
in %

Space-time yield

1.54
3.11
6.22
9.33

23.8
25.1
23.1
21.4

61.7 54.66 45.7 44.2

10.3
18.6
21.9
24.3

50.4
70.0
63.7
56.1

51.8
46.6
36.8
33.2

The following results from the results obtained: According to the process of the invention, optimum results are obtained with amounts of catalyst which are significantly less than the amounts that have to be used in the known method. While according to the process of the invention with lower catalyst concentrations, higher degrees of conversion are obtained than with higher catalyst concentrations, it is with the known Procedure exactly the other way around. The productivities are significantly greater than in the method of the invention in the case of the known method.

example 1

400 g of an aqueous silica brine with a solids content of 30% were placed in a beaker which was placed on an electric hot plate. 151 g of powdered ammonium dodecamolybdenum cerate were slowly added to the sol with stirring. A canary-yellow sludge was created, which was heated to boiling while stirring. A solution of 308 g of bismuth nitrate in 200 ml of dilute nitric acid was then slowly added. After further heating with stirring, the mixture thickened. It was transferred to an evaporating dish and dried in an oven at 130 ⁰ C. The product formed was then calcined in a muffle furnace ^{at 500 ° C. for 4 hours.}

The catalyst mixture consisted of 37% bismuth oxide, 33% dodecamolybdic acid and 30% SiO ₂ . The mixture was pulverized and sieved, whereupon 146 ml of the catalyst with a particle size of about 0.11 to 0.35 mm were introduced into the reactor described. A gas stream consisting of 164 ml of propylene, 917 ml of air and 639 ml of water vapor was then passed into the reactor per minute, measured under normal conditions. The reaction ^{temperature was 425 °} C. and the contact time was 2 seconds. 7.34 g of acrolein were obtained within 60 minutes. This corresponded to a degree of conversion of 29.8%> a yield of 55.0% and a space-time yield of 50.2 g / l / hour.

Example 2

A gas stream consisting of 101 ml of propylene, 665 ml of air and 403 ml of water vapor, measured under normal conditions, was introduced per minute into the reactor described above, which was filled with a catalyst mixture consisting of 37% bismuth oxide, 33% dodecamolybdic acid and 30% silicon dioxide The reaction ^{temperature was 450 °} C. and the contact time was 3 seconds. After an operating time of 1 hour, 4.94 g of acrolein were obtained, corresponding to a degree of conversion into acrolein of 32.6%, a yield of 56.4% and a space-time yield of 33.8 g / l / hour.

Example 3

150 g of the catalyst described in Example 1 were filled into the fluidized bed reactor. The reactor temperature was 449 ° C. Per minute was in the reactor is made of 302 ml propylene, 1788 ml air and 1200 ml water vapor, measured under normal

7 8

conditions, existing gas flow fed in. The contact time was 1 second from 267 ml of propylene and 1332 ml of air. Existing gas streams were introduced into the reactor in one hour. The 9.12 g of acrolein corresponding to a degree of conversion reactor temperature was 483 ° C. and the contact time of 20.1%, a yield of 41.9% ^UI * d of 2.7 seconds. 2.85 g of acrolein space-time yield of 62.4 g / l / hour were obtained in 30 minutes. 5 corresponding to a degree of conversion of 14.2%

and a yield of 30%. Example 4

Example 9

150 g of the catalyst described in Example 1

A catalyst consisting of 82% was filled, whereupon a gas stream, silica, 8% bismuth oxide and 10% dodecamolyb consisting of 117 ml of propylene, 643 ml of air and 478 ml of diacid into the reactor, manufactured. For this purpose, 66.6 g of dilute nitric acid were introduced into 40 ml of water vapor, measured under normal conditions, with heating. The reactor temperature was given as bismuth nitrate pentahydrate. At the same time, 408 ^° C. and the contact time were 3 seconds. 4.14 g of acrolein, corresponding to a stabilized 30% strength silica brine, were added to a 2-1 beaker with 1093 g of ammonia. The degree of conversion of 23.6%, a yield of sol, was acidified with 43 ml of dilute nitric acid (Ver-45.3% and a space-time yield of 28.3 g / l / ratio of nitric acid to water = 1: 3) . Hour received. Then, while stirring, 47.7 g of pulverized material was obtained

ao ammonium dodecamolybdoceratoctahydrate in the sol

Example 5 given. Then the slurry

the bismuth nitrate solution added. It was then

150 g of the 37% bismuth oxide, 33% dodecamolyb- the slurry was stirred for a further 70 minutes under diceric acid and 30% silicon dioxide. The slurry was then transferred to a catalyst in the fluidized bed described and transferred to a reactor with stirring, whereupon it was evaporated to dryness on a steam bath every minute. The 107 ml propylene, 692 ml air and 427 ml water vapor, dish was then left to stand overnight in an oven at a temperature of 120 ° C., measured under normal conditions. Thereupon gas flow was introduced into the reactor. The preparation was the 3-hour heating at reactor temperature was 410 ⁰ C and the contact time 30 250 ⁰ C and heating for 2 hours at 45O ⁰ C in a 3 seconds. 6.72 g of acrolein muffle furnace were calcined in one hour. The calcined preparation was crushed and finely ground according to a degree of conversion to acrolein of 41.8%, a yield of 71.1% and a 150 ml of the catalyst thus obtained

Space-time yield of 46 kg / l / hour was obtained. was now in the fluidized bed reactor described

35 brought. The reactor was at a temperature

Example 6 heated ^from 404 ⁰ C. Then it was in the reactor

a gas stream consisting of 159 ml propylene, 944 ml

150 g of the catalyst described in Example 1, air and 477 ml of steam, are fed in. the were placed in the fluidized bed reactor described - acrolein yield was 37.6%, the space-time filled, whereupon a gas flow per minute, consisting of 40 yield 16 g / l / hour, from 331ml propylene, 1654 ml air and 1325 ml

Water vapor, measured under normal conditions, example 10

was introduced into the reactor. The reactor temperature was 45O ⁰ C and the contact time was 1 second, it is a catalyst consisting of 25% announce to. In one hour, 10.3 g of acrolein were produced from silicic acid, 15% bismuth oxide and 60% dodeca, corresponding to a degree of conversion of 20.7%, a molybdenum acid. The preparation took place, yield of 46.1% and a space-time yield as described in Example 9, starting from 124.9 g of 70.5 g / l / hour. Bismuth nitrate pentahydrate, 285.2 g ammonium dodeca-

molybdenum acid octahydrate and 333.3 g silica

Example7 5 ° ^so "· ^ ¹⁰ - Catalyst were at a temperature of

404 ⁰ C and a contact time of 2.3 seconds per

Using 150 g of the described minute 196 ml of propylene and 1161 ml of air reacted. The catalyst was in the fluidized bed described. The acrolein yield was 52.1%, the space-time reactor a gas flow per minute consisting of 152 ml yield 48.7 g / l / hour. Propylene, 852 ml air and 575 ml water vapor, 55

measured under normal conditions, implemented. The example 11

Reactor temperature was 435 ° C and the contact time

2.1 seconds. 8.96 g of acrolein were obtained in 80 minutes. A catalyst consisting of 10%

corresponding to a degree of conversion of 29.4%. Silica, 50% bismuth oxide and 40% dodecamino Yield of 52.3% and a space-time 60 lybdic acid. Making the kata yield of 44.8 g / l / hour. lysators took place as described in Example 9, from

starting from 520 g of bismuth nitrate toentahydrate, 238.5 g

Example 8 Ammonium Dodecamolybdenic Acid and 166.7g Kie

selsäuresol. At one temperature on the catalyst

This example shows that the method of the invention, 65 out of 370 ⁰ C and a contact time of 1.5 Seauch without water vapor is temperature feasible. In the reactor described per minute 369 ml of propylene and 2180 ml of air, 200 g of the example 1 were reacted. The yield of acrolein was 23.7%, the catalyst described was charged. The space-time yield per minute is 33.2 g / l / hour.

No protection is claimed here for the manufacture of the catalysts.

Claims (4)

Patent claims: 1. Process for the production of acrolein by oxidation of propylene with oxygen or Oxygen-containing gases at elevated temperature in the presence of a solid, molybdenum and Bismuth-containing catalyst, characterized in that the oxidation at Temperatures from 300 to 600 ° C in the presence of a catalyst consisting of a mixture from bismuth oxide and a heteropoly acid of the formula H ₈ [Ce (Mo ₂ O ₇ ) ₆ ] * 5 is carried out, the proportion of the two catalyst components in the mixture in each case 3 to 75 percent by weight. 2. The method according to claim 1, characterized in that the method at a temperature from 350 to about 500 ° C. 3. Process according to Claims 1 and 2, characterized in that the oxidation is in the presence takes place by air. 4. The method according to claim 2 or 3, characterized in that the molar ratio of propylene to oxygen is about 1: 0.05 to about 1:10 and the catalyst is 37 percent by weight Bismuth oxide, 33 percent by weight dodecamolybdic acid and 30% silicon dioxide as Carrier exists. Considered publications:
German Auslegeschriften Nos. 1 070 612, 1 079 615; French Patent No. 1,272,358;
British Patent No. 821,999;
U.S. Patent Nos. 2,451,485, 2,776,316. 509 628S92 7.65 © Bundesdruckerei Berlin