DE2203710B2 - Process for the production of unsaturated aldehydes and acids - Google Patents

Description

corresponds to where A is an alkali metal, B is phosphorus, arsenic or a mixture of both and C is at least one element from group IIA and II B of the Periodic Table of the Elements, a is a number from 0 to less than 0.1, b is a number of 0 to 3, c is a number from 0.1 to 10, c / and e are each a number from 0.1 to 6, / is a number from 8 to 16 and χ is the number of oxygen atoms that saturate the valences of the others existing elements are sufficient.

30th

The invention relates to a process for the production of unsaturated aldehydes and acids from propylene, Isobutylene or mixtures thereof by reacting these olefins at a temperature in the range of about 260 to 482 ° C and at a pressure of about 0.5 to 5 atmospheres with a molecular oxygen containing gas in the presence of certain oxides of bismuth, molybdenum and other elements Catalysts; it relates in particular to a process for converting propylene and / or Isobutylene into the corresponding unsaturated aldehydes and unsaturated carboxylic acids acrolein, methacrolein, Acrylic acid or methacrylic acid.

From GB-PS 1182 824 a process for the production of unsaturated aldehydes such as acrolein is by Oxidation of olefins in the gas phase in the presence of oxides of iron, arsenic, molybdenum and Catalysts containing bismuth are known. However, the yields obtained are not satisfactory.

The method according to the invention is characterized in that the optionally on a carrier material applied catalyst of the empirical formula

⁵⁵

corresponds to where A is an alkali metal, B is phosphorus, arsenic or a mixture of both and C is at least one element from group II A and II B of the Periodic Table of the Elements, a is a number from 0 to less than 0.1, b is a number from 0 to 3, c is a number from 0.1 to 10, d and e are each a number from 0.1 to 6, / a number from 8 to 16 and χ is the number of oxygen atoms which saturate the valences of the others existing elements are sufficient.

The catalyst used according to the invention has a number of advantages, which to the effective and economic implementation

Contribute considerably to the procedure. So even at considerably lower temperatures they become higher Obtained yields of the desired end products. The catalyst has to do this under the reaction conditions of the process has an excellent redox resistance. Finally, the catalyst has a high Activity and selectivity for the conversion of olefins into useful oxygenated products a low bismuth content; therefore, the cost of the essential components of the catalyst is small amount. This low cost of the catalytic) components combined with the ease of use Manufacture of the catalyst make this catalyst very good from an economical point of view attractive.

The high activity of this catalyst with a low bismuth content is surprising with regard to in US-PS 29 41 007, in which a method for Production of unsaturated aldehydes and ketones from -olefins in the presence of one from bismuth molybdate or bismuth phosphorus molybdate existing catalyst, and US Pat. No. 3,171,859 in which a process for the production of unsaturated aldehydes in the presence of an oxide of iron, Bismuth, phosphorus and molybdenum-containing catalyst is described, and those specified there Degrees of conversion. Another advantage that is achieved with the method according to the invention is in that it is possible with this process to convert the olefins directly into unsaturated aliphatic acids to convert. Under suitable conditions, oxidation of olefins can lead to high yields are obtained on the unsaturated aliphatic acids and the investment costs for the plant in a technical one-step process for converting, for example, propylene to acrylic acid are considerable less than with the two-step process.

The reactants necessary for the preparation of the invention The unsaturated aldehydes and unsaturated carboxylic acids used are oxygen on the one hand and propylene or isobutylene and mixtures thereof. The olefins can be mixed with paraffin hydrocarbons, for example ethane, propane, butane and pentane may be mixed, for example the starting material be a propylene / program mixture. This makes it possible without special preparation to use ordinary refining streams. Without adverse effects, diluents, such as B. nitrogen and the carbon oxides, may be present in the reaction mixture.

Any source of oxygen can be used in the process of the present invention. the end For economic reasons, however, air is preferably used as the oxygen source. From the purely technical From a standpoint, relatively pure molecular oxygen gives equivalent results. That The molar ratio of oxygen to olefin in the feed mixture in the reaction vessel should be within of the range 5: 1 to 0.5: 1 and a ratio of about 1: 1 to 3: 1 is preferred

It was found that in some cases by water in the introduced into the reaction kettle Gas mixture, the selectivity of the reaction and the yield of unsaturated aldehydes and / or acids can be improved. However, water is not essential, since water will be used in the course of the reaction is formed. In general, the molar ratio of water added is 7.11 olefin when water

3 4

added, within the range of about 0.25 removal of the carbonyl and carboxylic acid compounds.

up to 20: 1. Ratios on the order of 1: 1 to the resulting product mixture remaining

up to 4: 1 are particularly useful. to remove carbon dioxide and water with the

The reaction occurs at a temperature within the remainder of the unreacted olefin and oxygen of the range from about 260 to about 482 ° C through-5 containing mixture and fed into the reactor leads. The preferred temperature range is about recycled a In the event that instead of 288 to about 399 ° C The pressure at which the reaction of molecular oxygen is air as an oxidizing agent is carried out, has a certain influence on the one used, can that after the separation Conversion and the reaction should be at about atmospheric product and the other carbonyl product pressure or at a pressure slightly above atmospheric with a non-polar solvent, for example r pressure (2 to 5 atmospheres). a hydrocarbon reaction, are washed, The apparent contact time is not critical and it is used to recover unreacted olefin and in Contact times can be within the range of this case can the residual gases about 0.1 to about 50 seconds will be applied, which will be discarded. It can also include the addition of one optimum contact time will of course vary depending on the inhibitor used to prevent the olefin from being converted, but in general the unsaturated products will generally be ionized during the winning contact time of 1 second to 15 seconds, preferably in stages.

The yield of unsaturated carboxylic acids is in the process according to the invention

due to higher reaction temperatures, higher ratios, the catalyst used is one

Oxygen to olefin and longer contact times, a mixture, a complex or a compound

th favored and the reverse applies to the oxides of the empirical formula given at the beginning.

Yields of unsaturated aldehydes. When one is a preferred catalyst composition

maximum yield of unsaturated acids is desirable in which A is potassium and C is a group metal

is, it is favorable to mean the formed unsaturated aldehyde II A of the Periodic Table of the Elements

Again about the catalysts according to the invention to 25 and the atomic ratios of the elements in the above

recycle. The recycling of the implemented empirical formula lie within the range, ie the

Aldehyde can mean a is a number from 0 to 0.09 with the recycling of the process, b is a number from 0 to

steam and / or unreacted olefin 1, c is a number from 0.1 to 7, d and e are each a number of

be combined. 1 to 4 and / the number 12. Most preferred is one

In general, to carry out the invention 30 catalyst composition in which the metal of the

according to the method any device group II A of the Periodic Table of the Elements

which is used for the implementation of magnesium

Oxidation reactions in the vapor phase is suitable. The catalyst according to the invention can be carried out according to one of the numerous methods of preparation carried out continuously or intermittently by catalysts known to those skilled in the art, the. The catalyst bed can be made up. For example, the catalyst Fixed bed when using a particulate or can be produced by co-precipitation of the pelletized catalyst with large particles, or various components. The jointly failed alternatively around a so-called »fluidized bed or fluidized mass can then be dried and transferred to a suitable bed «act. The fluidized bed reactor can be milled from a size 40. Alternatively, the common open column can consist or the reactor can slurried a sam precipitated material and after Majority of perforated, spray-dried over the entire length of the usual methods. Of the Column horizontally stacked trays catalyst can in the usual way in oil to contain, as in US Patent 32 30 246 pellets are extruded or formed into spheres, is described. The reactor can be before or after the 45 Alternatively, the catalyst components can with Introduction of the initial reaction mixture onto which the carrier is mixed and in the form of the slurry Reaction temperature are brought. In the case of a subsequently dried or silicon dioxide However, it is preferred on an industrial scale, or any other carrier can be impregnated with the process continuously and in ned. A particularly abrasion-resistant form of the One such system is the circulation of the 50 catalyst can be prepared by adding the unreacted olefin provided. Although the support material to the catalyst in two stages, Catalyst is redox-resistant, it may be required- first regenerating or reactivating a mixture of the active catalyst cases by adding torkomponenten and 0 to 60 wt .-% of the total the catalyst is produced and heat-treated at an elevated temperature with air in the carrier material and Contact then brings the rest of the carrier material to the

The reaction products can be after any powdered form of the heat treated catalyst

known methods can be obtained. One such adds a more detailed description of how to make one

Method consists in removing the exhaust gases from attrition resistant catalyst in the below

the reactor with cold water or a suitable example given below.

Solvent washes to the reaction products 60 The alkali metal can be in the form of an oxide or

to remove from it. The final extraction of the products of any salt which, when calcined, will form the oxide

can be carried out in a conventional manner. Preferred salts are

will. The effectiveness of the washing process can reduce nitrates, which are easily available and easily soluble,

When using water as a detergent improves bismuth can be in the form of an oxide or in the form

if a suitable salt of any kind is added to the water, which upon calcining the oxide

Adding wetting agent. If provided in the invention, are introduced. Most preferred are

moderate process of molecular oxygen as Oxyda- water-soluble salts that are inside the catalyst

tion center! is used, which can be easily disDeared after the and which in the heat treatment

formation of stable oxides. The most preferred salt for the introduction of bismuth is bismuth nitrate for the introduction of the iron component Any iron compound can be used in the catalyst which, on calcination, yields oxides As with the other elements, the water-soluble salts are preferred because of the ease with which they are can be dispersed uniformly within the catalyst. Most preferred is ferric nitrate. Group II metals of the periodic System? of the elements can be introduced in a similar manner. However, the metals can of Group II of the Periodic Table of the Elements also in the form of the insoluble carbonates or Hydroxides are introduced into the catalyst, which result in the heat treatment of the oxides. To the Introduction of the molybdenum component can be any molybdenum oxide, for example the dioxide, trioxide, Pentoxide or sesquioxide, preferably a hydrolyzable or decomposable one Molybdenum salt, such as B. molybdenum halide is used A preferred starting material is ammonium heptamolybdate. Arsenic can be introduced in the form of ortho-arsenic acid. The phosphorus can be found in The form of an alkali metal, alkaline earth metal or ammonium salt are introduced, but it is preferably introduced in the form of phosphoric acid other elements can be introduced starting from the metal, the metal with a oxidizing acid, such as. B. nitric acid, oxidized and then incorporated the nitrate into the catalyst. in the in general, however, the nitrates are readily available and form a very convenient starting material.

Other variations of the starting materials are obvious to the person skilled in the art, in particular r> when the above-mentioned preferred starting materials for reasons of economy in the large-scale production are unsuitable. In general, any compounds which the desired catalyst components can be used provided that they are upon heating to a temperature within the range specified below, the oxides for the erfindungsger. give an external catalyst.

C sr catalyst can be used without a support 4> who 's and has excellent activity. The Katilysator can also be combined with a carrier were on and preferably he will with at least 10 to combined to about 90% by weight, based on the total composition, of a carrier compound. All known carrier materials, such as. B. silicon dioxide, aluminum oxide, zirconium oxide, titanium oxide, alundum, silicon carbide, aluminum oxide-silicon dioxide, inorganic phosphates, such as. B. aluminum phosphate, silicates, aluminates, borates, carbonates and Materials such as B. pumice stone, montmorillonite and the like., Which are among the when using the catalyst occurring reaction conditions are stable, can be used.

The catalytic activity of the system is increased t> o by heating to an elevated temperature. In general, the catalyst mixture is dried and heated to a temperature of about 260-982 ⁰ C _1, preferably from about 482 to about 7O4 ° C for about 1 to about 24 hours or more. If the activity to is not sufficient, the catalyst can be heated further to a temperature above approximately 538 ^° C., but below a temperature which is suitable for the Catalyst is harmful In general, the activation of the catalyst at the higher temperatures is carried out within a shorter time the activation is sufficient under the given conditions is determined by a stain test of a sample of the Material determined for the catalytic activity. Activation is best carried out in an open Chamber carried out, allowing air or oxygen to circulate, so that the consumed oxygen can be replaced. In addition, there is also a pretreatment or activation of the catalyst before it Use with a reducing agent in the presence of a limited amount of air at a temperature favorable within the range of 260 to 538 ° C. A preferred process for the preparation of the catalyst according to the invention and a more detailed description of the process according to the invention are given in the following examples.

Examples 1 to 4

The catalysts of these examples were prepared according to the processes described in US Pat. No. 2,941,007 and US Pat. No. 3,171,859

Examples 5, 7 to 9 and 11 to 14

The catalysts used in these examples were prepared by essentially the same procedure as described below using the appropriate starting materials. A catalyst with the composition 80% by weight K ₀ .o7Mg4 ₅ Fe4Bi2Po.5Moi20si / 20 _{% by weight SiO 2} was prepared by dissolving 70.6 g (NH ₄ JeMOzO ₂₄ · 4 H2O in water with minimal heating. To this, 1.9 g of H ₃ PO ₄ (85% by weight) and 76.7 g of colloidal silicon dioxide sol (30% by weight) were added successively with stirring. The solution was stirred for 15 minutes at room temperature. To this solution 53.7 g of Fe (NOj) ₃ ■ 9 H ₂ O, dissolved in water, were added and then 38.5 g of Mg (NO ₃ J ₂ · 6 H ₂ O, 0.23 g of KNO ₃ and 32, 4 g of Bi (NO ₃ ) ₃ · 5 H ₂ O dissolved in water containing 8 cm ^{3 of} concentrated HNO 3 (68% by weight) was added. The slurry was heated with constant stirring until gelation occurred. The gel became then at about 132 ⁰ C dried. The resulting catalyst for 5 hours at 316 ° C for 20 hours heat-treated at 549 ⁰ C and then brought to a particle size of 0.84-0.42 mm.

Example 6

A non-supported catalyst of the composition Mg ₄₁ SFe ₄ Bi ₂ Po ₁ SMOi ₂ OsI was prepared by dissolving 70.6 g (ΝΗ ₄ ) 6Μθ7θ24 · 4H ₂ O in water with minimal heating; g of H ₃ PO ₄ (85% by weight) were added. The solution was stirred at room temperature for 15 minutes. 53.7 g of Fe (NO ₃ ) ₃ .9 H ₂ O, dissolved in water, were added _{to this solution, followed by 38.5 g of Mg (NO 3} ) _2. 6 H ₂ O and 32.4 g of Bi (NO ₃ J ₃ · 5 H ₂ O dissolved in water containing 6 cm ^{3 of} concentrated HNO ₃ (68% by weight) was added. The slurry was heated with constant stirring until gelation occurred. The gel became then dried at about 132 ° C. The catalyst obtained was heat-treated for 5 hours at 316 ° C. and for 20 hours at 549 ° C. and then brought to a size of 0.84-0.42 mm.

Example 10

An abrasion-resistant catalyst with the composition 60% by weight Mg ₄₅ Fe ₄ Bi ₂ Po ₁ SMOi ₂ O ₅ IMO% by weight SiO ₂ was prepared by dissolving 706 g (ΝΗ ₄ ) δΜθ7θ2 ₄ · 4 H ₂ O in 570 cm ³ Water with minimal heating and subsequent mixing with 19 g of 85% H ₃ PO ₄ . To this solution were added 767 g of 30% silica sol and then successively an _{aqueous solution containing 537 g of Fe (NO 3 I 3} · 9 H ₂ O in 250 cm ^{3 of} water and a 385 g of Mg (NO ₃ I ₂ · 6 H ₂ O in ^{aqueous solution containing 190 cm 3 of} water was added to this vigorously stirred solution. A solution consisting of 324 g of Bi (NO ₃ I ₃ · 5 H ₂ O, 30 cm ^{3 of} 68% HNO ₃ and 380 cm ^{3 of} water) was added. The slurry was heated with stirring until a non-fluid cake was obtained, the solid was then treated for 5 hours at a temperature of 316 ° C. After mechanically pulverizing the dry solid, 1000 g of powder containing 1125 g of 30% silica sol and a sufficient amount of water to make a 40 weight percent solids slurry, the mixture was milled in a porcelain ball mill for 20 minutes, and the resulting slurry then passed in a 135 cm diameter Bowen spray dryer with an inlet temperature of Spray-dried at 288 ° C and an outlet temperature of 177 ° C. The microspherical product obtained in the spray dryer was placed in an oven at 138 ° C. The temperature was increased to a temperature of 316 ° C. over a period of 1 hour and held at this temperature for 3 hours. Before the material was discharged into the fluidized bed reactor for testing, the catalyst was subjected to a final calcination at 593 ° C. for 15 hours.

Example 16

A catalyst with the composition 80% by weight Ko.o7Mg ₄ . ₅ Fe4Bi ₂ Po.5Moi ₂ 0 ₅ | / 20 wt .-% SiO _{2 produced} as follows:

212 g of (NH ₄ ) ^ MOtO ₂₄ · 4 H ₂ O were dissolved in water with minimal heating, then 5.7 g of H ₃ PO ₄ (85% by weight) and 230 g of colloidal silica sol (30% by weight) were added in succession with stirring. -%) admitted. 161 g of Fe (NO ₃ I ₃ · 9 H ₂ O, dissolved in water, were added _{to this solution, and then 115.5 g of Mg (NO 3 I 2} ■ 6 H ₂ O and 0.69 g of KNO ₃ , dissolved in water, were added one after the other. 97.2 g of Bi (NO ₃ I ₃ · 5 H ₂ O, dissolved in water containing 9 cm ^{3 of} concentrated HNO ₃ (68% by weight) were added to the vigorously stirred slurry.

Table I.

Conversion of propylene into acrolein and acrylic acid

Molar ratio of the starting material: C _{3 VLuPtZH 2} O = 1/11/4

Catalyst volume = 5 cm '

Particle size of the catalyst = 0.84-0.42 mm, lead = 15 minutes

Running time = 30 minutes

give. The slurry was stirred continuously for about 15 minutes. The slurry was then spray-dried and the powder obtained in the spray dryer was further dried ^{in an oven at 110 ° C. for 16 hours.} The dry powder obtained was mixed well with 1% by weight of graphite and compacted into pellets 0.109 cm × 0.327 cm in size by means of a conventional pelletizing machine. The pellets were heated to 232 ° C. for 5 hours to obtain the

κι nitrates to decompose and then they were 20 hours long calcined at 549 ° C.

The reactor used to carry out the oxidation reactions in Examples 1 to 15 was a standard reactor with a fixed bed of catalyst. The catalyst volume was about 5 cm ³ and the size of the catalyst particles was 0.84-0.42 mm. The gases were metered into the reactor with rotameters. The reaction products were obtained by washing the reactor effluent gases with water and then analyzed by gas chromatography.

The percentage conversions given in the examples in the unsaturated oxygen-containing hydrocarbon compounds are defined as follows:
Conversion into an unsaturated aldehyde or into an unsaturated carboxylic acid in mol% per pass

Moles of aldehyde or acid obtained
M il used olefin

100.

The oxidation reactions that occur with the catalyst compositions of the invention using of propylene and isobutylene as the hydrocarbon feedstock are disclosed in US Pat

η summarized the following Tables I and II. These Data are compared to the conversions reported in US Pat. Nos. 2,941,007 and 3,171,859 Catalyst compositions were obtained in Examples 1 to 4 of Table I and in Example 14 of Table II are given. The data in these tables show that those with the invention Catalysts obtained per pass conversions (conversions) in acrolein, methacrolein, acrylic acid and methacrylic acid were significantly higher than those obtained with the known catalysts were obtained. The catalysts of the invention gave comparable yields of unsaturated Aldehydes and unsaturated acids in both fixed bed reactors and fluidized bed reactors Use of pelletized or fluid-type catalysts.

Bei- catalyst composition

Reaction temperature ^{in 0 C}

Contact part in seconds

Mole percent conversion per pass in

Acrolein

Acrylic acid

1 50% Bi, PMo, ₂ O, ₂ /50% SiO ₂

2 50% Βί, ΡΜο, ₂ Ο ₅₂ /50% SiO ₂

360
360

5.0

22.8
35.6

3.5

10

continuation

example
No.

Catalyst composition

Reaction contact cell mole percent conversion temperature in seconds per cycle in in C

3 50% Fe ₄₅ Bi ₄₅ PMo | ₂ O ₅₂ /50% SiO ₂

4 50% Fe ₄₅ Bi ₄ . ₅ PMo ₁₂ O ₅₂ /50% SiO ₂

5 80% Mg _f ,, ₅ Fe ₃ Bi | P ₍₎ , 5MO | ₂ O ₄ , / 20% SiO,

6 100% Mg ₄ 5Fe ₄ Bi ₂ P ₀ SMOi ₂ O ₅ ,

7 80% Mg _4. , Fe ₄ Bi ₂ P ₀ . ₅ MON | ₂ O ₅₁ /20% SiO ₂

8 80% Mg ₄ "Fe ₄ Bi ₂ P", ₅ MO | ₂ O _M / 20% SiO ₂

9 80% Mg ₄ 5Fe ₄ Bi ₂ P _{11 5} Mü | ₂ O ₅₁ /20% SiO ₂

10 60% Mg ₄₅ Fe ₄ Bi ₂ P ", ₅ MO | ₂ O _5l / 40% SiO ₂ abrasion resistant (particle size 0.30-0.18 mm)

11 80% K ₀₀₇ Mg ₄₅ Fe ₄ Bi ₂ P ₀₅ Mo ₁₂ O ₅ , ^ '/ ,, SiO ₂

12 80% ₄₅ Mg Fc ₄ Bi ₂ As _above .5MO | ₂ O ₅₁ /20% SiO ₂

13 80% Mg ₄₅ Fe ₄ Bi ₂ Mo ₁₂ O ₅₀ /20% SiO ₂

319
360
360
360
319
360
360
319

Table Il

Conversion of isobutylene into methacrolein and methacrylic acid, reaction temperature = 360 ° C
Contact line = 2.5 seconds
Molar ratio iC ₄ Vair / H ₂ O = 1/11/4

example

Catalyst Composition 2.5 5.0 5.0 5.0 2.5 2.5 5.0 2.5

5.0 2.5 2.5

Acrolein acrylic acid 22.0 3.9 48.5 6.8 64.4 10.6 78.3 5.7 67.3 7.8 54.3 17.2 51.2 20.6 64.2 8.6 71.7 12.1 68.3 10.2 65.9 5.3

Mole percent conversion per pass to

Methacrolein

Methacrylic acid

50% Fe ₄₅ Bi ₄₅ P | Mo | ₂ O ₅₂ /50% SiO ₂ 100% Mg ₄₅ Fe ₄ Bi ₂ P ₀ SMo ₁₂ O ₅ I 28.6 48.5

4.0 4.8

Table III

Conversion of propylene to acrolein and acrylic acid or isobutylene to methacrolein and methacrylic acid

Contact time: 5 seconds

Molar ratio: C ₃ H ₆ or iC ₄ H ₈ / air / H ₂ O = 1/11/4

By-catalyst product
game

Temp.% Yield per pass

C Total acrolein acrylic acid

16 80% Rb ₀₀₅ Mg ₇ Fe ₃ BiP _{0 5} MoI ₂ C ^ on 20% SiO ₂

17 80% Cs ₀ U ₅ Mg ₇ Fe ₃ BiP ₀₅ MOi ₂ O ^ on 20% SiO ₂

18 80% K ₀₀₇ Ca, Mg ₃₅ Fe ₄ Bi ₂ P ₀₅ MOi ₂ O., to 20% SiO ₂

19 80% K ₀₀₇ Be ₁ Mg ₃₅ Fe ₄ Bi ₂ P ₀₅ MOi ₂ O _x to 20% SiO ₂

20 80% Ku _-07 Zn ₂ Mg _2-5 Fe ₄ Bi ₂ P _0-5 Mo ₁₂ O _x on 20% SiO ₂

21 80% K _0-07 Cd ₁ Mg ₆ Fe ₃ Bi ₁ P _0-5 Mo ₁₂ O _x on 20% SiO ₂

22 90% Cs _0-09 Ca ₂ MgSFe ₃ BiP _0-2 Mo ₁₂ O _x on 10% SiO ₂

311 74.9 8.3 83.2 330 73.8 7.2 81.0 360 72.1 10.3 82.4 360 74.2 9.9 84.1 360 66.9 5.9 72.8 360 71.8 7.4 79.2 360 75.4 63 81.7

Claims (1)

Claim: Process for the production of unsaturated aldehydes and acids from propylene, isobutylene or mixtures thereof by reacting these olefins at a temperature in the range of about 260 to 482 "C and at a pressure of about 03 to 5 Atmospheres with a molecular oxygen-containing gas in the gas phase in the presence a catalyst containing oxides of bismuth, molybdenum and other elements, thereby characterized in that the catalyst optionally applied to a support material of Molecular formula