CS208792B2 - Method of making the acrolein and methacrolein - Google Patents

Description

The present invention relates to a process for the production of acrolein and methacrolin by gas-phase oxidation of propylene or isobutylene with molecular oxygen at elevated temperature in the presence of water vapor and other inert gas and also in the presence of a catalyst

Mo _a Fe _b GOcNidBi _e KIPgAxOy, where

A is at least one element selected from the group consisting of aluminum, rhenium, germanium and scandium, a is 12, b is 0.5 to 7.0, c is 0 to 15, d is 0 to 15, e is 0.1 to 15 4.0, f is 0.01 to 0.5, g is 0 to 4, x is 0.005 to 0.5, and y is a number which depends on the valence and atomic ratio of the other catalyst elements.

The present invention relates to a process for the production of acrolein and methacrolein by oxidation of suitable olefins in the presence of complex oxide catalysts. The process for producing acrolein and methacrolein from propylene and isobutylene usually consists in oxidizing the compounds in the gas phase with oxygen and most often air, in the presence of a catalyst consisting of oxygen compounds of elements such as molybdenum, cobalt, nickel, iron, bismuth, phosphorus , cadmium, zinc and tellurium.

According to British Patent No. 1,038,274, the process of oxidizing propylene to acrolein is carried out in the presence of a catalyst consisting of bismuth oxides, molybdenum and iron. This method achieves acrolein yield of not more than 75% f

The method of German Patent No. 2,038,749 relates to a process for the oxidation of propylene which is carried out in the presence of a catalyst comprising oxygenated compounds of bismuth, molybdenum, iron, nickel, cobalt, phosphorus and potassium. Furthermore, a catalyst for the oxidation of propylene is known, consisting of, in addition to the elements mentioned in the above-mentioned German patent, also tungsten, silicon and thallium.

The main drawback of the catalysts mentioned above - · · lies mainly in the low yield. of unsaturated aldehydes, which are obtained by oxidizing olefins using said catalysts and in the presence of thallium in the catalyst-forming compounds, which is a serious hazard to workers, not to mention environmental pollution by elements of toxic properties.

The invention is based on the oxidation of propylene or isobutylene in the vapor phase at a temperature of 250 to 450 ° C and at a pressure between atmospheric pressure of up to 1 MPa, in a gas mixture of 5 to 18% by volume of oxygen, 10 to 60% by volume of water. 20 to 70% by volume of inert gas and 1 to 10% by volume of propylene or isobutylene in the presence of a catalyst of the empirical formula

Ma _a Fe _b CocNic | Bi _e K _f P _g AxOy, where

A is at least one of aluminum, rhenium, germanium and scandium, a is 12, b is 0.5 to 7.0, c is 2 to 15, d is 1 to 15, e is 0.1 to 4, 0, f is 0.01 to 0.5, g is 0.2 to 4, x is 0.005 to 0.5 and y is a number which depends on the valence and atomic ratio of the other catalyst elements.

The contact time of the reactive gas mixture with the catalyst is 0.5 to 10 seconds. The reaction can be carried out both on the fixed catalyst bed and in the fluid bed.

According to the invention, a maximum of 99 mole% conversion of propylene or isobutylene, 90-97 mole% selectivity to acrolein and about 75 mole% selectivity to methacrolein can be achieved. .

The oxidation of propylene or isobutylene to acrolein or methacrolein is carried out according to the invention in the vapor phase in the presence of an oxidation catalyst of the above formula, supported on silica gel, diatomaceous earth, titanium dioxide or zirconium oxide, 450 ° C, at a pressure between atmospheric pressure up to 1 MPa, and a gas mixture consisting of 1 to 10% by volume of propylene or isobutylene, 5 to 18% by volume of molecular oxygen, 10 to 60% by volume of water vapor and 20 to 70% by volume is passed through the catalyst. inert gas.

The catalyst contact time is 0.5 to 10. seconds.

By the method of the invention, it is possible to achieve a high yield of olefin oxidation to the corresponding unsaturated aldehydes by passing the olefins through a catalyst composed of components such as aluminum, rhenium, scandium and germanium.

The process according to the invention is further illustrated by examples.

Example 1

The catalyst is produced at a temperature of · 95 · CJ by mixing solutions of catalyst-forming elements, which are in the form of metal salts, with the addition of microgranular silica "Arsil" as closed pore supports, and urea as blowing agents, in an amount of 3 · % By weight, based on the mass of the oxygenates of the catalyst, consisting of

MO [2Fe3 ^Co <| ^{5 N i2} 5 ^B ILKO, 07Po 5 ^and LO, 050y »and contains about 30% carrier.

cm 3 of the pelleted and at 600 ° C calcined catalyst are charged into a 25 mm diameter tube reactor made of stainless steel.

The catalyst is heated to a predetermined reaction temperature and then the desired reactants are introduced into the reactor. The bulk composition of the resulting gaseous reaction mixture is shown in Table 1 below.

Propylene is oxidized at a temperature of 320 to 480 ° C and the other production parameters are changed as shown in Table 1, which also shows the results of propylene oxidation. The amount of propylene oxidation products formed in the mixture after the reaction is determined by known analytical methods based on the calculation of propylene conversion as well as the selectivity and yield of acrolein and acrylic acid.

The oxidation conditions and results are summarized in Table 1.

Example 2

A catalyst is prepared which consists of:

MO] ₂ Fe _{: 3} Go ₃ Ni ₂ Bi i K д P e R e ₄ O _y and contains 35% by weight of very fine silica "Aerosil 200".

Ammonium carbonate is added to the ammonium molybdate solution during the catalyst synthesis in an amount of 20% by weight based on the weight of the catalytically acting oxygen compound.

Example 3

A catalyst is prepared which consists of:

Mo _J2 Fe ₂ Co ₅ Ni ₄ Bii PiGe _{0 (} 050 _y and contains 30% ^(by weight "Arsil" as carrier).

12% by weight of urea, based on the weight of the active ingredient, are introduced into the catalyst preparation.

Example 4

A catalyst is prepared which consists of:

MOj2Fe3CO _^<4R 5NÍ _2; - _BÍiKo> () _j 7Po 5SCo o50y and _also contains 15% by weight of zinc oxide as a carrier.

During production, 15% of urea and oxalic acid, based on the weight of active catalyst mass, are used as blowing agents. Urea and oxalic acid are used in a 2: 1 ratio.

Example 5

A catalyst is prepared which consists of:

Mo _{l2 Fe3Co4>} 5NÍ2 /> BiiKo _J (IP) Alo ^ .osGeo / ísOy and contains 10% by weight of minced · porcelain as carriers.

During production, 5% by weight of starch, based on the weight of the catalytically active mass, is used as blowing agent.

Example 1 a d 6

A catalyst is prepared which consists of:

Mo ₁₂ Fe ₂ CO'5NÍ2 5BiiKoiP IAL _{t 0} o ^ ^^ Reo Oy and which contains 30 wt% ,, Arsilu "as carriers.

In the preparation of the catalyst, 15% by weight of melamine, based on the weight of the catalytically active crumb, is added.

Example 7

A catalyst is prepared which consists of:

МО ^! 12РезС04 (5 tit12 (5В11Коо7Ро, 5к ^е О? Й5иео ^ 052Со, 050у) and contains 1% by weight of titanium dioxide as carrier.

During production, 5% by weight of sucrose, based on the weight of the catalytically active mass, is added before the catalyst is formed.

Example 8

A catalyst having the composition is produced

MonFejCo NbBýKfji P ^ _o ^ ^ Geo Alo ^ Oy and contains 30% by weight of "Aerosil" as carriers.

During production, 10% by weight of urea is added before shaping the catalyst.

Example 9 (Comparative)

A catalyst is prepared which consists of:

M0 ₁₂ Fe3CO4 _/ 5Ne ₂₎ 5BiCo ₍ 07₽0 ₎ 50y and contains 30% by weight of silica · "Arsil" as carrier. The catalyst is shaped without the addition of a blowing agent.

Propylene is oxidized with the catalysts shown in Examples 2 to 9. Example 1 is carried out using a mixture of reactants consisting of 6% by volume propylene, 59% by volume air and 35% by volume steam vapor.

The apparent contact time, calculated at 0 ° C and 0.1 MPa, is 3.6 seconds. The process is carried out at atmospheric pressure. The reaction temperature and oxidation results are shown in Table 2 below.

Example 10

Using a catalyst and a reactor as in Example 1, a vapor gas mixture consisting of 6.5% isobutylene, 60% air and 33.5% water vapor is oxidized, the percentages being by volume.

The reaction temperature is 400 ^° C and the contact time is 5 seconds. Using these conditions, 98.5% isobutylene is reacted, with a selectivity of 75.3% to methacrolein.

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Example Table 2 Reaction temperature ° C Propylene Conversion ^! ° / o Selectivity% mol. Yield% / mol. Acrolein Acrylic acid Acrolein Acrylic acid 2 360 96.2 95.3 2.5 91.7 2.4 3 380 96.9 93.9 2.2 91.0 2.1 4 380 94.7 92.4 1,8 87.5 1.7 5 380 95.3 93.8 2.6 89.4 2.5 6 380 96.1 93.4 96.0 2.7 92.3 2.6 7 380 95.8 2.4 92.0 2.3 8 380 97.2 96.7 2.1 94.0 2,0 9 380 91.0 92.1 4Д 83.8 3.7

Claims (1)

OBJECT OF THE INVENTION Process for producing acrolein or methacrolelin by oxidizing a gas mixture containing 1 to 10% by volume of propylene or isobutylene, 5 to 18% by volume of molecular oxygen, 10 to 60% by volume of water vapor and 20 to 70% by volume of inert gas at 250 up to 450 ° C at a pressure between atmospheric pressure and 1.0 MPa and in the presence of an oxygen catalyst containing molybdenum, iron, cobalt, nickel, bismuth, potassium and phosphorus, characterized in that the reaction is carried out in the presence of a catalyst of empirical formula Mo _and Fe _b Co _c NidBi _e PGA _{Row x} O _y, where A is at least one element that the groups comprising aluminum, rhenium, germanium and scandium, a is 12, b is 0.5 to 7.0, c is 2 to 15, d is 1 to 15, e is 0.1 to 4, 0, f is 0.01 to 0.5, g is 0.2 to 4, x is 0.005 to 0.5 and у is a number that depends on the valence and atomic ratio of the other catalyst elements.