KR800001329B1 - Method of manufacture for acrylic and methycrylic acid - Google Patents

Abstract

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Description

Method for preparing methacrylic acid and acrylic acid

The present invention comprises a catalyst consisting of molybdenum, phosphorus, bismuth, copper, oxygen, halogen (one type selected from chlorine, bromine, iodine) and at least one of Fe, Cr, Ni, Mn, Sb, Te, Rh and Pd as necessary. The present invention relates to a process for producing acrylic acid and methacrylic acid by vapor phase oxidation of acrolein and metaacrolein with molecular oxygen.

Several types of catalysts are known which are effective when oxidizing acrolein and methacrolein to produce acrylic acid and methacrylic acid, respectively. However, the yield when using the previous catalysts was low. The catalyst of the present invention is a preferred catalyst having very high efficiency in producing acrylic acid and methacrylic acid. In particular, in the case of producing acrylic acid and methacrylic acid by gas phase oxidation of acrolein and metaacrolein with molecular oxygen in the presence of the catalyst of the present invention, a very high yield can be obtained and the selectivity to acrylic acid and methacrylic acid is also high.

The present invention relates to a method for producing acrylic acid or methacrylic acid by vapor-phase oxidation of acrolein or metaacrolein with molecular oxygen in the presence of steam at 200 to 500 ° C. using an oxide catalyst of the following structural formula.

Mo ₁₂ Pa Bib Cu c Mα Xe Of

In the above structural formula, M is at least one element selected from iron, chromium, nickel, manganese, tellurium, palladium, antimony and thorium, X is one halogen selected from chlorine, bromine and iodine and a, b and c are 0.001 to 10, d is 0 to 10, e is a positive number of 5 or less and f is the number of oxygen for the component to stabilize the equilibrium.

The catalyst of the present invention has very good yields in the production of methacrylic acid and acrylic acid, is easy to use, and has economical properties by inducing a reaction at low temperatures. In addition, the calorific value of the reaction is small, so that it is easy to control the reaction.

The most important point of the present invention is the use of a catalyst.

The catalyst of the present invention may be any catalyst as long as it has the above-described composition. This catalyst can be produced by a known treatment method, for example, by coprecipitation of a soluble salt and calcining a product.

The catalyst of the present invention preferably has a limit of composition. Ie a, b and c in the range of 0.01 to 5 and e in the range of 0 to 1.0. Also preferred are catalysts in which a is from 1 to 1.5, b is from 0.1 to 0.5, c is from 0.1 to 1.0, e is from 0.01 to 0.5, and e is preferably from 0.01 to 0.20 and α is zero. Particularly preferred catalysts are those wherein X is chlorine and the main concern is the fact that chlorine, bromine or iodine are present as essential catalyst components.

In preparing the catalyst, various catalyst components are first mixed and then the final product is calcined to obtain a catalyst.

There are many such methods of mixing-calcination, but no specific method is used to prepare the catalyst.

There are several ways to prepare a preferred catalyst, one of which is to add a residual component to an aqueous slurry or solution containing molybdenum and / or phosphorus, distill the aqueous mixture and calcinate the resulting catalyst to make a catalyst. to be.

Molybdenum used to prepare the catalyst of the present invention includes molybdenum trioxide, phosphomolybdic acid, molybdic acid, ammonium hepta molybdate and the like, and phosphorus compounds used in the present invention are orthophosphoric acid, metaphosphoric acid, tri Phosphoric acid, oromide, and pollutant. Other components of the catalyst include oxides, acetates, formates, sulfates, nitrates, carbonates, oxyhalides or halides.

The catalyst of the present invention may be prepared by mixing a catalyst component in an aqueous slurry or an aqueous solution, heating and drying, and then calcining the resulting catalyst.

More preferred as the catalyst of the present invention is after refluxing phosphoric acid and molybdenum trioxide (which may be used for economic reasons phospho molybdic acid) in water for 1.5 to 3 hours and adding the remaining components to the slurry (at least one of the components Halide or oxyhalide), which is prepared by boiling to a thick paste, drying in air at 110 ° to 120 ° C., and then calcining the resulting catalyst. However, it is not possible to determine exactly where the halogen atom in the catalyst of the present invention exists in the structure, but by infrared irradiation and X-ray inspection, the catalyst mainly consists of phosphomolybdate, and the halogen is in the form of molybdenum oxyhalide. It can be assumed to exist.

The present invention achieves good results when using a coated catalyst consisting of an inert support material having a diameter of 20 microns or more and having an outer surface and a coating of an active catalyst strongly adhering to the outer surface of the inert support. In particular, the coated catalyst consists of an inert support having an outer surface and an active catalyst material adhered to the outer surface.

The support forms the inner core of the catalyst. This support should be inert and the diameter should be at least 20 microns.

As a support to be used in a conventional reactor in the present invention, a sphere having a diameter of 0.2 to 2 cm is preferable, and such an inert support includes aluminium, silica, alumina-silica, silicon carbide, titania, zirconia, and the like. Especially preferred are rhodium, silica, alumina, alumina-silica and the like.

The catalyst should contain a suitable amount of catalytically active component and a support, the limit of which is reduced by the balance of the relative activity of the active ingredient and the support, preferably 10 to 100% by weight of the catalytic activity based on the weight of the support. It contains an ingredient.

The coated catalyst can be prepared in several ways. The basic method first partially wets the support with a suitable liquid. At this time, the entire outer surface should not be wetted. If the whole surface is wet, touch it to dry. If the support is wet, the active ingredient may clump into several masses when the catalytically active ingredient is coated on the support.

This partially wet support is contacted with a powder of catalytically active ingredient and the mixture is slowly stirred until a catalyst is formed. Stirring at this time is most commonly performed by placing a partially wet support in a rotating tube and adding the catalytically active component until it is no longer absorbed by the support.

Such a method is economically helpful to the present invention.

Calcination of the catalyst is carried out by heating the dried catalyst component at 300 to 700 ℃. Different kinds of calcination methods produce different kinds of catalysts. The most suitable calcination conditions for the catalyst of the invention are described in the examples.

The reactants used in the reaction of the present invention are metaacrolein and oxygen. Molecular oxygen is supplied mainly to the reaction in the air, but oxygen gas can also be supplied. The amount of oxygen to be used is preferably about 0.5 to 4 moles per mole of methacrolein.

The reaction temperature varies depending on the type of catalyst used. In general, the reaction temperature is about 200 to 500 ° C, preferably 250 to 370 ° C.

The reaction is carried out in a stationary or fluidized bed and the contact time is from 1 second to 20 seconds of water. The reaction pressure may be atmospheric pressure or lower or higher, but about 0.5 to 4 atm is preferable.

When used in the reactor, the catalyst can be used in a supported or unsupported state and the support includes aluminium, silica, alumina, boronphosphate, zirconia, silicon carbide, titania and the like.

The catalyst is coated on the fixed bed with the catalytically active ingredient acrolein or metacrolein and an inert support.

Alternatively, the active ingredient and the support may be mixed before the inert support is coated.

It is also understood that by the present invention, acrolein or metaacrolein can be gas phase oxidized using the catalyst of the present invention while a small amount of chlorine, iodine or bromine or inorganic or organic halides can be added to the feed.

Using the catalyst of the present invention has the advantage that it is possible to produce acrylic acid or methacrylic acid in a high yield while reducing the amount of by-products.

[Example 1-9]

Various catalysts of the present invention are prepared as follows.

Example 1

_{Mo 12 P 1 · 32 Bi 0} · 5 Cu 0 · 25 Cl 0 · 06 Ox

A. Dissolve 89.6 g (0.6 mol Mo) of molybdenum trioxide and 7.6 g (0.067 mol P) of 85% -phosphoric acid in 500 ml of distilled water to form a slurry, and heat-stirr it for 3 hours to form phosphomolybdic acid (yellow green). Then 2.5 g (0.0125 mol Cu) of copper acetate was added thereto (no color change), and a solution of 7.9 g (0.025 mol Bi) of bismuth chloride in 4 ml of concentrated hydrochloric acid was added thereto.

The mixture is boiled, dried and dried overnight at 110 ° C. in air. The catalyst is ground and screened with 20-30 mesh and then calcined at 400 ° C. under an air supply of 40 ml / min.

B. A large batch of catalyst is prepared by dissolving 3500 ml of distilled water, 432 g of molybdenum trioxide, 38 g of phosphoric acid, 12.5 g of copper acetate, and 39.5 g of bismuth chloride in 25 ml of concentrated hydrochloric acid. The mixture was then boiled and dried at 110 ° C. in an oven overnight, then crushed, screened and calcined under air supply at 400 ° C., 40 ml / min.

Example 2-9

These catalysts are calcined in the same manner as in Example 1.

Example 2

_{Mo 12 P 1 · 32 Bi 0} · 5 Cu 0 · 25 Cl 0 · 04 Ox

Prepared in the same manner as in Example 1B.

Example 3

_{Mo 12 P 1 · 32 Bi 0} · 5 Cu 0 · 25 Cl 0 · 05 Ox

In the method of Example 1, 118.3 g of commercial phosphomolybdic acid and 1.84 g of 85% phosphoric acid instead of molybdenum trioxide and phosphoric acid were prepared.

Example 4

_{Mo 12 P 1 · 32 Bi 0} · 5 Cu 0 · 25 Cl 0 · 055 Ox

In the method of Example 1, 15 ml of concentrated nitric acid was used instead of hydrochloric acid.

Example 5

_{Mo 12 P 1 · 32 Bi 0} · 5 Cu 0 · 25 Cl 0 · 06 Ox

In the method of Example 1, 5.8 g (0.025 mol Bi) of bismuth oxide was prepared instead of bismuth chloride.

Example 6

_{Mo 12 P 1 · 32 Bi 0} · 5 Cu 0 · 25 Ox

Performed by the method of Example 1, without using halogen and hydrochloric acid is prepared using 5.8 g (0.025 mol Bi) bismuth oxide instead of bismuth chloride.

Example 7

_{Mo 12 P 1 · 32 Bi 0} · 5 Cu 0 · 25 Ox

In the method of Example 6, instead of bismuth oxide, 12.1 g of Bi (No ₃ ) ₃ .5H ₂ O was prepared.

Example 8

Mo ₁₂ P ₁ · 32 Cu ₀ · 15 Bi ₀ · 3 Fe ₀ · 1 Cr ₀ · 1 Ni ₀ Cl ₀ · 04 Ox

86.4 g (0.6 mol Mo) of molybdenum trioxide and 7.6 g (0.067 mol P) of 85% phosphoric acid are dissolved in 500 ml of distilled water to form a slurry. 1.5 g (0.0075 mol Cu) copper acetate, 4.8 g (0.015 mol Bi) bismuth chloride, 5 ml concentrated hydrochloric acid, 1.4 g (0.005 mol Fe) ferric chloride hydrate, 0.4 g (0.005 mol Cr) Chromium oxide and 0.9 g (0.005 mole Ni) nickel acetate are added.

Example 9

_{Mo 12 P 1 · 32 Cu 0} · 2 Bi 0 · 4 Sb 0 · 1 Ni 0 · 05 Cl 0 · 04 Ox

Dissolve 86.4 g (0.6 mol Mo) of molybdenum trioxide and 7.6 g (0.067 mol P) of 85% -phosphoric acid in 500 ml of distilled water to form a slurry, which is heated and refluxed (yellow green) for 0.7 g (0.005). When molar sb) antimony oxide is added, it becomes dark green with 2 g (0.01 mole Cu) copper acetate, 6.3 g (0.02 mole Bi) mischloride chloride, 3.5 ml concentrated hydrochloric acid, and 0.4 g (0.0025 mole Ni) nickel Acetate is added.

Example 10-18

This example relates to a process for producing methacrylic acid using the various catalysts of the present invention.

The catalyst used here is manufactured by the method as mentioned above in various component ratios.

The catalyst particles were filled into a 20 cc fixed bed reactor consisting of a 0.3 cm axial thermowell tube of 1.3 cm in diameter and the reactor was heated to the reaction temperature under air supply, followed by metaacrolein: air: vapor 1: 6.2: 5.2 It is fed at a rate of and brought into contact with the catalyst for 4 to 5 seconds.

The reaction was carried out for 1 to 5 hours and the product was collected and analyzed.

The reaction conditions and results are shown in Table I. The following definitions were used to determine the carbon atoms in the feed and product.

TABLE I

Example 19-21

Effect of Calcination of Catalyst and Reaction Temperature on Preparation of Methacrylic Acid Using Mo ₁₂ P ₁ · 32 Bi ₀ · 5 Cu ₀ · 25 Cl ₀ · 04 Ox Catalyst

Example 19-20

The catalyst of Example 2 was calcined at 400 ° C. for 3 hours in the absence of air and reacted with metaacrolein at 343 ° C.

The second reaction proceeds at 377 ° C.

Example 21

The catalyst of Example 2 is reacted by the method of Example 19 but the catalyst is calcined in the presence of air and reacted with metaacrolein at 313 ° C. The results are shown in Table II below.

TABLE II

Therefore, the calcination of the appropriate catalyst and the reaction temperature are very important for obtaining the desired yield of methacrylic acid according to the present invention.

[Examples 22-28]

Preparation of methacrylic acid using the catalyst of the present invention

Example 22

A catalyst consisting of 20% Mo ₁₂ P ₁ · 32 Bi ₀ · 5 Cu ₀ · 25 Cl ₀ · 07 Of + 80% alundum is prepared as follows.

105.9 g (0.6 mol M) of ammonium heptamolybdate, (NH ₄ ) ₆ Mo ₇ O ₂₄ 4H ₂ O was dissolved in 500 ml of distilled water, stirred and boiled, and 7.9 g (0.025 mol Bi) of bismuth chloride was added thereto. After adding a solution dissolved in 15 ml of concentrated hydrochloric acid, 2.5 g (0.0125 mole Cu) of copper acetate, 7.7 g (0.066 mole P) of phosphoric acid and 2.5 G hydrazine hydrate are added. The mixture is boiled, dried and dried overnight at 110 ° C. The material is ground and screened to 80 mesh or less, then 50 g of Alundum is moistened with 1.8 g of water and 16.7 g of catalyst powder is added in equal portions to 5 times and coated on Norton SA 5223 1/8 ″ Alundumball. Alundum rolls into a jar. The resulting material is dried overnight at 110-120 ° C. in an oven.

Example 23

_{20% Mo 12 P 1 · 32} Bi 0 · 5 Cu 0 · 25 Cl 0 · 16 Of + 80% Al rundum

By the above-mentioned method, it is manufactured in the absence of hydrazine hydrate.

Example 24

_{15% Mo 12 P 1 · 32Bi} 0 · 5Cu 0 · 25Cl 0 · 06Of + 85% Al rundum

The catalyst active ingredient was prepared by the method of Example 1A, ground and then screened to 50 mesh or less. Then, 25 g of Alundum was moistened with 1.3 g of water and 4.17 g of catalyst powder was added at once to add Norton 5223 1/8 ″ Alun. Coating on Doomball. The material thus produced is dried overnight at 125 ° C. in an oven.

Example 25

_{25% Mo 12 P 1 · 32Bi} 0 · 5Cu 0 · 25Cl 0 · 06Of + 75% Al rundum

In the method of Example 24, Alundum is moistened with 1.8 g of water and 6.94 g of catalyst component powder is added in two equal parts.

Example 26

_{40% Mo 12 P 1 · 32Bi} 0 · 5Cu 0 · 25Cl 0 · 06Of + 60% Al rundum

In the method of Example 24, Alunduum was soaked with 2.1 g of water, 11.1 g of catalyst component powder was added in three equal parts, and the catalyst was dried overnight at 110 ° C. in an oven.

Example 27

_{25% Mo 12 P 1 · 32Bi} 0 · 5Cu 0 · 25Cl 0 · 06Ox + 75% Al rundum

The catalyst active ingredient was prepared by the method of Example 1B, and then pulverized and screened to 50 mesh or less. Then, 50 g of Alundum of 10 to 30 mesh was soaked with 4 g of water and 3 times of 16.7 g of catalyst powder 3 times, 6.7 g is added once to coat Norton SA 5223 Alunduum 10/30 mesh particles. The resulting material is dried at 110-120 ° C.

Example 28

_{35% Mo 12 P 1 · 32Bi} 0 · 5Cu 0 · 25Cl 0 · 06Ox + 65% Al rundum

In the method of Example 27, alunduum was soaked with 2.2 g of water and 26.9 g of catalyst component powder of 80 mesh or less were added in equal portions four times.

Example 29-48

This example relates to a process for producing methacrylic acid using several types of catalysts of the present invention.

The catalyst is made using various component ratios in a similar manner as described above, and calcined in air at 400 ° C. to form an active catalyst containing an Alundum support that is strongly and continuously adhered to the coating mole of the active catalyst.

The catalysts prepared in Examples 22-28 were placed in the reactors described in Examples 10-18, respectively, and the reactors were heated to the reaction temperature in the presence of air, and then the metacrolein: air: vapor: nitrogen was added in a ratio of 1: 5.3: 5.6: 4.6. It is fed at a rate and brought into contact with the catalyst for 2.5 to 2.7 seconds. The reaction conditions and results are shown in Table III.

TABLE III

Example 49

The catalyst of Example 1A, by the method described in Examples 10-18.

Acrylic acid is prepared from acrolein using Mo ₁₂ P ₁ .32Bi ₀ .5Cu ₀ .25Cl ₀ .06Of. As a result, a 75.1% one-pass yield, a total conversion of 85.3%, and a selectivity of 88% were obtained at 317 ° C.

Claims (1)

A method for producing methacrylic acid or acrylic acid by gas phase oxidation of methacrolein or acrolein, respectively, at 200 to 500 ° C., in the presence of steam, if necessary, using a catalyst of the following structural formula. Mo ₁₂ Pa Bib Cuc Md Xe Of In the above structural formula, M is at least one element selected from iron, chromium, nickel, manganese, tellurium, palladium, antimony, rhodium or mixtures thereof, X is at least one halogen selected from chlorine, bromine or iodine, a, b And c is 0.001 to 10, d is 0 to 10, e is 0 to 5, and f is the number of oxygen to stabilize the equilibrium of the components.