KR20120079617A - Process for preparing mo-bi based multi-metal oxide catalyst - Google Patents

Abstract

PURPOSE: A manufacturing method of MO-BI based composite metal oxide is provided to improve selectivity by applying an effective catalyst activation regulation method. CONSTITUTION: A manufacturing method of MO-BI based composite metal oxide comprises the following steps: manufacturing a catalyst suspension by dissolving molybdenum based compound, bismuth based compound, salt of a first metal, salt of a second metal, and salt of a third metal; adjusting pH of the catalyst suspension as 0.1-3.3 by adding organic alkali; and desiccating the catalyst suspension. The first metal one or more which are selected from Fe, Zn, Cr, Mn, Cu, Ru, Pd, Ag, and Ru. The second metal is one or more which are selected from Co, Cd, Ta, Pt, and Ni. The third metal is one or more which are selected from Na, K, Li, Rb, Cs, Ca, Mg, Sr, and Ba.

Description

Method for producing M-metal composite metal oxide {PROCESS FOR PREPARING Mo-Bi BASED MULTI-METAL OXIDE CATALYST}

The present invention relates to a method for producing a Mo-Bi-based composite metal oxide, and more particularly, the present invention by applying an effective catalyst activity control method to produce (meth) acrylic acid and acrolein from propylene and the like in excellent yield It relates to a method for producing a Mo-Bi-based composite metal oxide.

Processes for producing unsaturated fatty acids from olefins via unsaturated aldehydes are representative of catalytic vapor phase oxidation. In the partial oxidation reaction of olefins, molybdenum and bismuth containing complex oxides, molybdenum and vanadium containing complex oxides, or mixtures thereof are used as catalysts. Process of oxidizing propylene or isobutylene to produce (meth) acrylic acid via (meth) acrolein, oxidizing naphthalene or orzaylene to produce phthalic anhydride or partially oxidizing benzene, butylene or butadiene to produce maleic anhydride The process is typical.

Generally, the final product (meth) acrylic acid is produced by two stages of catalytic gas phase partial oxidation from propylene, propane, isobutylene, t-butylalcohol or methyl-t-butylether (hereinafter referred to as propylene). Is generated. That is, in the first step, propylene or the like is oxidized by oxygen, dilute inert gas, water vapor, and any amount of catalyst to produce (meth) acrolein, and in the second step, oxygen, dilute inert gas, water vapor, and any amount of catalyst The (meth) acrolein is oxidized to produce (meth) acrylic acid. The first stage catalyst is a multi-component metal oxide based on Mo-Bi, and mainly oxidizes propylene to produce (meth) acrolein. In addition, some (meth) acrolein continues to oxidize on this catalyst to produce some (meth) acrylic acid. The second stage catalyst is a multi-component metal oxide based on Mo-V. The second stage catalyst mainly oxidizes (meth) acrolein in the (meth) acrolein-containing mixed gas generated in the first stage to mainly produce (meth) acrylic acid.

The reactor for performing such a process may be provided to perform the above two steps in one apparatus, or may be provided to perform the two steps of processes in different devices.

As mentioned above, in most fixed bed gas phase catalytic reactions, the reactant concentration is a reaction in which the reactant concentration is lowered and the product is increased from the reactor inlet to the outlet. The characteristic of the fixed-bed gas phase catalytic reaction is that hot spots are generated at the front end of the catalyst layer where the concentration of the reactants is high. The by-products thus generated cause deactivation due to catalyst poisoning, and such high temperature conditions cause catalyst component sublimation and sintering to shorten catalyst life. In order to solve this problem, a number of catalysts having different occupied spaces and techniques for filling a plurality of catalysts prepared by varying the type or component ratio of the D (alkali) component in the catalyst composition so that the activity increases from the inlet to the outlet direction are provided. There are known techniques for filling a plurality of reaction zones so that the occupied space becomes smaller toward the outlet direction. (A) preparation of several different catalysts in terms of (a) occupancy volume, (b) calcination temperature and / or (c) alkali metal element and / or amount, and each reaction tube in a high bed cylindrical tube reactor. The reaction zone provided by separating the catalyst layer of the catalyst into two or more layers in the axial direction of the tube is known to increase the catalytic activity from the starting gas inlet direction to the outlet direction.

As described above, a multi-component metal oxide catalyst for producing acrolein acrylic acid from propylene based on Mo-Bi (one stage catalyst) and a multi-component metal oxide catalyst for producing acrylic acid from acrolein based on Mo-V (two stage catalyst) The activity control technology for) is a catalyst activity control technology through alkali metal type and / or amount control and catalyst calcining temperature control, activity control technology by changing the occupied area of the catalyst, and a mixture of a catalyst and an inert material This is known. In the commercialization process, the catalyst activity is controlled by adjusting the alkali metal type and amount, and therefore, a small amount of alkali metal is used so that it is not uniformly distributed. In addition, the activity control method through the control of the catalyst firing temperature also has a limitation in regulating the catalyst activity reproducibly due to non-uniform temperature variation in the kiln.

The present invention is to provide a method for producing a Mo-Bi-based composite metal oxide having excellent selectivity as a more effective and reproducible catalyst activity control method to produce (meth) acrylic acid and acrolein in high yield from propylene and the like. do.

The present invention provides a method for producing a Mo-Bi-based composite metal oxide represented by Formula 1, Molybdenum-based compound; Bismuth compounds; Salts of at least one metal selected from the group consisting of Fe, Zn, Cr, Mn, Cu, Pd, Ag, and Ru; Salts of at least one metal selected from the group consisting of Co, Cd, Ta, Pt, and Ni; Dissolving a salt of at least one metal selected from the group consisting of Na, K, Li, Rb, Cs, Ca, Mg, Sr, and Ba in water to prepare a catalyst suspension, and adding organic alkali to the catalyst suspension. To adjust the pH of the catalyst suspension to 0.1 to 3.3, and to dry the catalyst suspension provides a method for producing a Mo-Bi composite metal oxide.

[Formula 1]

Mo _a Bi _b M ¹ _c M ² _d M ³ _e M ⁴ _f M ⁵ _g M ⁶ _h O _i

Where

Mo is molybdenum,

Bi is bismuth,

M ¹ is at least one element selected from the group consisting of W, Sb, As, P, Sn, and Pb,

M ² is at least one element selected from the group consisting of Fe, Zn, Cr, Mn, Cu, Pd, Ag, and Ru,

M ³ is at least one element selected from the group consisting of Co, Cd, Ta, Pt and Ni,

M ⁴ is at least one element selected from the group consisting of Al, Zr, V and Ce,

M ⁵ is at least one element selected from the group consisting of Se, Ga, Ti, Ge, Rh and Au,

M ⁶ is at least one element selected from the group consisting of Na, K, Li, Rb, Cs, Ca, Mg, Sr, and Ba,

a, b, c, d, e, f, g, h, and i represent the atomic ratio of each element,

When a = 12, b is 0.01-20, c is 0-20, d is 0.001-15, e is 0.001-20, f is 0-20, g is 0-10, h is 0.001-10, i is It is a numerical value determined according to the oxidation state of each said component.

The present invention also provides a Mo-Bi-based composite metal oxide prepared according to the above production method and represented by Chemical Formula 1.

The present invention also provides a method for producing (meth) acrylic acid from at least one reactant selected from the group consisting of propylene, propane, isobutylene, t-butyl alcohol or methyl-t-butyl ether, wherein the Mo-Bi system Provided are methods for producing (meth) acrylic acid and (meth) acrolein using a composite metal oxide as a catalyst.

Hereinafter, a method of preparing a Mo-Bi-based composite metal oxide according to a specific embodiment of the present invention and a Mo-Bi-based composite metal oxide prepared according to the present invention, and a method of preparing (meth) acrylic acid using the same as a catalyst will be described in detail. Shall be. However, this is presented as an example of the invention, whereby the scope of the invention is not limited, it is apparent to those skilled in the art that various modifications to the embodiments are possible within the scope of the invention.

Unless specifically stated throughout this specification, "comprising" or "containing" means including any component (or component) without particular limitation, and excludes the addition of other components (or components). Cannot be interpreted as.

According to one embodiment of the invention, in the method for producing a Mo-Bi-based composite metal oxide represented by the formula (1), Molybdenum-based compound; Bismuth compounds; Salts of at least one metal selected from the group consisting of Fe, Zn, Cr, Mn, Cu, Pd, Ag, and Ru; Salts of at least one metal selected from the group consisting of Co, Cd, Ta, Pt, and Ni; Dissolving a salt of at least one metal selected from the group consisting of Na, K, Li, Rb, Cs, Ca, Mg, Sr, and Ba in water to prepare a catalyst suspension, and adding organic alkali to the catalyst suspension. Thereby adjusting the pH of the catalyst suspension to 0.1 to 3.3, and drying the catalyst suspension may be provided a method for producing a Mo-Bi composite metal oxide.

[Formula 1]

Mo _a Bi _b M ¹ _c M ² _d M ³ _e M ⁴ _f M ⁵ _g M ⁶ _h O _i

Wherein Mo is molybdenum; Bi is bismuth; M ¹ is at least one element selected from the group consisting of W, Sb, As, P, Sn and Pb; M ² is at least one element selected from the group consisting of Fe, Zn, Cr, Mn, Cu, Pd, Ag and Ru; M ³ is at least one element selected from the group consisting of Co, Cd, Ta, Pt and Ni; M ⁴ is at least one element selected from the group consisting of Al, Zr, V and Ce; M ⁵ is at least one element selected from the group consisting of Se, Ga, Ti, Ge, Rh and Au; M ⁶ is at least one element selected from the group consisting of Na, K, Li, Rb, Cs, Ca, Mg, Sr, and Ba; a, b, c, d, e, f, g, h, and i represent the atomic ratio of each element; When a = 12, b is 0.01-20, c is 0-20, d is 0-15, e is 0-20, f is 0-20, g is 0-10, h is 0-10, i is It is a numerical value determined according to the oxidation state of each said component, Preferably, when a = 12, b is 0.01-15, c is 0-10, d is 0.001-10, e is 0.001-10, f is 0- 15, g is 0-10, h is 0.001-10, i is a numerical value determined according to the oxidation state of each said component.

The inventors of the present invention, more effectively than the prior art by controlling the activity of the Mo-Bi-based composite metal oxide catalyst used in the production of (meth) acrylic acid and (meth) acrolein from propylene and the like by adjusting the pH in the coprecipitation reaction step The present invention was completed by confirming that it is possible to prepare (meth) acrylic acid and (meth) acrolein in high yield by controlling activity.

In particular, the present invention is not a technique for achieving activity control by changing the content of alkali metal or the type of alkali metal as a new activity control method of the Mo-Bi-based metal oxide catalyst as the first stage reaction catalyst, but using a basic solution. After adjusting the pH of the catalyst suspension in which the salt of the metal component contained in water to 0.1 to 3.3, and drying it to produce a Mo-Bi-based composite metal oxide, it is excellent in reproducibility and stable catalyst of uniform quality Can be produced by According to the present invention, as described above, using the method of adjusting the pH to the optimum range, it is possible to produce a catalyst having a uniform catalyst composition, easy activity control and excellent reproducibility.

First, the Mo-Bi-based composite metal oxide production method of the present invention comprises the steps of preparing a catalyst suspension by dissolving or dispersing a salt of a metal component included in the composite metal oxide together with molybdenum-based compound and bismuth-based compound in water. do.

The metal component may be one or more selected from the group consisting of Fe, Zn, Cr, Mn, Cu, Pd, Ag, and Ru, and 1 selected from the group consisting of Co, Cd, Ta, Pt, and Ni. One or more species may be used, and one or more species selected from the group consisting of Na, K, Li, Rb, Cs, Ca, Mg, Sr, and Ba may be used.

In addition, the catalyst suspension is a salt of a metal selected from the group consisting of W, Sb, As, P, Sn, Pb, Al, Zr, V, Ce, Se, Ga, Ti, Ge, Rh, and Au. It may further include.

The molybdenum-based compound, bismuth-based compound, and the salt of the metal component is not particularly limited, and may be any compound that can be dissolved in water, including each metal component. For example, as starting materials, compounds which are already oxides or which can be converted into oxides by heating (ie, calcination) in the presence of at least oxygen, such as halides, nitrides, formates, oxalates, citrates, acetates, carbonates , Amine complexes, ammonium salts, hydroxides and the like can be used. At this time, the molybdenum-based compound, bismuth-based compound, and the salt of the metal component may be used in a content determined according to the stoichiometry based on the composition of each component contained in the final Mo-Bi-based composite metal oxide.

After preparing the catalyst suspension as described above, the method for producing the Mo-Bi composite metal oxide of the present invention comprises the step of adjusting the pH of the catalyst suspension to 0.1 to 3.3 by adding organic alkali to the catalyst suspension. .

The pH of the catalyst suspension can be adjusted to an optimum range according to the use of the final catalyst using organic alkalis, i.e., basic solutions such as pyridine, ammonia and the like. Here, the organic alkali may be an amine compound including an alkyl group having 1 to 12 carbon atoms or an aryl group, for example, pyridine, ammonia, methylamine, ethylamine, and the like.

The pH of the catalyst suspension adjusted by adding the basic solution as described above may be in the range of 0.1 to 3.3, preferably 0.3 to 3.1, more preferably 0.5 to 3.0. By maintaining the pH of the catalyst suspension in which the salt of the metal component included in the final catalyst is dissolved in water in the above-described range to produce a Mo-Bi composite metal oxide, it is possible to stably produce a catalyst of excellent reproducibility and uniform quality have.

In particular, the pH of the catalyst suspension can be adjusted according to the specific catalyst application of the finally produced Mo-Bi-based composite metal oxide. That is, when the Mo-Bi-based composite metal oxide is used as a catalyst in the first stage reaction in which (meth) acrolein and / or (meth) acrylic acid is produced from propylene or the like, the reaction gas in the reactor is filled in the reactor. The catalyst charged on the inlet side is called a front catalyst, and the catalyst charged on the reaction gas outlet side is called a rear catalyst. In this case, the pH of the catalyst suspension may be finely controlled to vary the catalytic activity depending on whether the Mo-Bi-based composite metal oxide is used as a front catalyst or a rear catalyst.

For example, when the Mo-Bi composite metal oxide is used as the front catalyst in the first step reaction, the sintering, fouling, recrystallization active phase sublimation due to the rapid exothermic reaction It is desirable to maintain lower activity than rear catalyst so that a phenomenon such as (sublimation of active phase) occurs to damage the catalyst or prevent channeling in the reactor. As such, in order to achieve an optimum range of activity as a front catalyst in the first stage reaction in which (meth) acrolein and / or (meth) acrylic acid are produced, the pH of the catalyst suspension is at least 1.0 or from 1.0 to 3.3. Can be adjusted high. That is, by increasing the pH of the catalyst suspension to increase the catalytic activity control effect, it is also possible to induce the prepared catalyst activity to be adjusted to a lower range to perform a stable reaction. On the other hand, when using the Mo-Bi-based composite metal oxide as a rear catalyst in the first step reaction, it is to maintain a high activity compared to the front catalyst to improve the conversion and yield of the overall process desirable.

At this time, the activity of the front catalyst may be 50% to 90%, preferably 55%, more preferably 85%, more preferably 60% to 80% of the activity of the rear catalyst have.

After adjusting the pH of the catalyst suspension in such an optimal range, the method for producing the Mo-Bi composite metal oxide of the present invention includes the step of drying the catalyst suspension. The drying step may first be evaporated to a solid containing the catalyst suspension.

Meanwhile, the Mo-Bi composite metal oxide prepared according to the present invention may be used alone by drying the catalyst itself as described above, or may be used by being supported by an inert carrier. When using the inert carrier together, the pH-adjusted catalyst suspension may be further carried out in contact with the inert carrier to carry the catalyst prior to the drying step. For example, the catalyst suspension may be supported on the carrier by a conventional supporting method such as vacuum, nozzle injection, or the like. The carrier may be porous or nonporous alumina, silica-alumina, silicon carbide, titanium dioxide, magnesium oxide, aluminum sponge, or the like. In addition, the carrier may be a cylindrical type, a hollow cylindrical shape, a sphere, but the shape is not particularly limited. For example, the cylindrical catalyst size preferably has a ratio (L / D) of length to diameter (outer diameter) in the range of 1 to 1.3, more preferably L / D = 1 ratio. In the case of cylindrical and spherical shapes, the outer diameter of the catalyst is preferably 3 to 10 mm, more preferably 5 to 8 mm.

In addition, the dried composite metal oxide may be further performed in the form of powder, tablets, granules through a grinding process. In this case, inorganic fibers such as glass fibers and various kinds of whiskers, which are widely known for the effect of improving the strength and friction resistance of the catalyst, can be added. In addition, in order to control the properties of the catalyst to have excellent reproducibility, additives well known as powder binders such as ammonium nitrate, cellulose, starch, polyvinyl alcohol, stearic acid and the like can be used.

The method for producing the Mo-Bi-based composite metal oxide of the present invention further comprises calcining the molded product or the product supported on the carrier at 300 to 600 ° C. for about 1 to 10 hours or more under a flow of 0.2 to 2 m / s. It may include. Firing may be carried out with an inert gas or an oxidizing atmosphere (e.g., air or a mixed gas atmosphere of inert gas and oxygen), other reducing atmospheres (e.g., inert gas, oxygen and a mixed gas of NH ₃ , CO and / or H ₂₎ . Atmosphere). In addition, the firing time may be from several minutes to several hours, and may generally be shortened as the temperature increases.

Meanwhile, according to another embodiment of the present invention, Mo-Bi-based composite metal oxide prepared by the method as described above may be provided. In particular, the Mo-Bi composite metal oxide may be represented by the following Chemical Formula 1.

[Formula 1]

Mo _a Bi _b M ¹ _c M ² _d M ³ _e M ⁴ _f M ⁵ _g M ⁶ _h O _i

Wherein Mo is molybdenum; Bi is bismuth; M ¹ is at least one element selected from the group consisting of W, Sb, As, P, Sn and Pb; M ² is at least one element selected from the group consisting of Fe, Zn, Cr, Mn, Cu, Pd, Ag and Ru; M ³ is at least one element selected from the group consisting of Co, Cd, Ta, Pt and Ni; M ⁴ is at least one element selected from the group consisting of Al, Zr, V and Ce; M ⁵ is at least one element selected from the group consisting of Se, Ga, Ti, Ge, Rh and Au; M ⁶ is at least one element selected from the group consisting of Na, K, Li, Rb, Cs, Ca, Mg, Sr, and Ba; a, b, c, d, e, f, g, h, and i represent the atomic ratio of each element; When a = 12, b is 0.01-20, c is 0-20, d is 0.001-15, e is 0.001-20, f is 0-20, g is 0-10, h is 0.001-10, i is It is a numerical value determined according to the oxidation state of each said component, Preferably, when a = 12, b is 0.01-15, c is 0-10, d is 0.001-10, e is 0.001-10, f is 0- 15, g is 0-10, h is 0.001-10, i is a numerical value determined according to the oxidation state of each said component.

The Mo-Bi composite metal oxide of the present invention may be used as a catalyst, and in particular, may be used as a catalyst for catalytic partial oxidation.

Further, according to another embodiment of the present invention, by using the Mo-Bi-based composite metal oxide represented by the formula (1) as a catalyst, propylene, propane, isobutylene, t-butyl alcohol or methyl-t-butyl ether A method for preparing (meth) acrylic acid and acrolein from one or more reactants selected from the group consisting of can be provided.

In the method for preparing (meth) acrylic acid and acrolein of the present invention, when the Mo-Bi-based composite metal oxide catalyst is filled in a reactor, the catalyst on the reaction gas inlet side of the reactor, that is, the front catalyst, reacts with the reaction gas outlet. It can be packed to be prepared using a catalyst suspension at a higher pH compared to the side catalyst, ie the rear catalyst.

Process conditions for the reaction for producing (meth) acrylic acid may be those that are generally used to prepare (meth) acrylic acid and (meth) acrolein from reactants such as propylene by gas phase catalytic oxidation. For example, in the range of 250-400 ° C., a gas mixture atmosphere containing propylene space velocity as starting gas 100 hr ⁻¹ , molecular oxygen to and an inert gas acting as a diluent (eg, nitrogen, carbon dioxide, vapor, etc.) The intended reaction may be carried out by contacting with the Mo-Bi based composite metal oxide catalyst under conditions such as temperature, pressure in the range of 0.1 to 3 kg / cm ² G, and the like.

The Mo-Bi composite metal oxide catalyst is filled with a catalyst on the reaction gas inlet side, that is, a front catalyst, in the reactor, so that at least 20% or 20% to 50% of the total filling height is preferably 25%. Or at least 25% to 50%, more preferably at least 30% or 30% to 50%. The shear catalyst of the Mo-Bi-based composite metal oxide may be filled in a range of 20% or more or 20% to 50% of the total filling height in terms of activity control.

In the method for preparing (meth) acrylic acid and acrolein of the present invention, the Mo-Bi-based composite metal oxide catalyst is charged with a shear catalyst to effectively control the catalytic activity, thereby yielding a yield of (meth) acrolein and (meth) acrylic acid by 89%. Above, preferably 90% or more can be significantly improved, acrylic acid and acrolein can be produced in high yield.

In the present invention, matters other than those described above can be added or subtracted as required, and therefore, the present invention is not particularly limited thereto.

The present invention provides a method for preparing a Mo-Bi-based composite metal oxide exhibiting activity suitable for the specific use of the catalyst according to the filling position in the reactor by introducing an effective catalyst activity control technology to adjust the pH of the catalyst suspension to the optimum range Provided are the prepared Mo-Bi based composite metal oxides, (meth) acrylic acid and acrolein using the same.

In particular, the Mo-Bi-based composite metal oxide prepared according to the present invention, in the preparation of (meth) acrolein and (meth) acrylic acid from propylene or isobutylene, undergoes reaction of a hot spot site in the first step. By effectively suppressing, it is possible not only to secure excellent thermal stability of the reaction catalyst, but also to produce high yields of (meth) acrylic acid and acrolein, and to perform a high load operation, thereby exhibiting excellent performance. Moreover, there is an effect that can easily adjust the catalyst activity according to the purpose by adjusting the pH of the catalyst suspension rather than adjusting the activity only by the amount of the alkali metal.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the scope of the present invention is not limited to the following examples.

Example  One

Solution (1) was prepared by dissolving 1,000 g of ammonium molybdate while heating and stirring 2,500 mL of distilled water at 70-85 ° C. A solution (2) was prepared by adding 274 g of bismuth nitrate, 228 g of iron nitrate, and 4.7 g of potassium nitrate to 400 mL of distilled water, mixing well, and adding 71 g of nitric acid. Solution (3) was prepared by dissolving 686 g of cobalt nitrate in 200 mL of distilled water. After the solution (2) and (3) was mixed, the catalyst suspension was prepared by mixing the solution (1) while maintaining the temperature of the solution at 40 ~ 60 ℃.

The pH of the suspension was adjusted to 0.50 using a 5% solution of aqueous ammonia in the catalyst suspension.

The pH adjusted suspension was dried to pulverize the resulting catalyst solids up to 150 μm. The pulverized catalyst powder was mixed for 2 hours and then molded into a cylinder. At this time, the outer diameter of the catalyst was molded to a size of 4.0 to 8.0 mm, and calcined at 480 ° C. for 5 hours in an air atmosphere to prepare a final Mo-Bi composite metal oxide catalyst (catalyst A). At this time, the composition ratio of the catalyst elements excluding oxygen is _{Mo 12 Bi 1 .2 Fe 1 .2} Co 5 K 0. _{1 was} .

Example  2

A final Mo-Bi composite metal oxide catalyst (catalyst B) was prepared in the same manner as in Example 1, except that the pH of the suspension was adjusted to 1.0 using a 5% solution of ammonia water in the prepared catalyst suspension.

Example  3

A final Mo-Bi composite metal oxide catalyst (catalyst C) was prepared in the same manner as in Example 1 except that the pH of the suspension was adjusted to 1.5 by using a 5% solution of ammonia water in the prepared catalyst suspension.

Example  4

A final Mo-Bi composite metal oxide catalyst (catalyst D) was prepared in the same manner as in Example 1 except that the pH of the suspension was adjusted to 2.0 using a 5% solution of aqueous ammonia in the prepared catalyst suspension.

Example  5

A final Mo-Bi composite metal oxide catalyst (catalyst E) was prepared in the same manner as in Example 1 except that the pH of the suspension was adjusted to 2.5 by using a 5% solution of ammonia water in the prepared catalyst suspension.

Example  6

A final Mo-Bi composite metal oxide catalyst (catalyst F) was prepared in the same manner as in Example 1, except that the pH of the suspension was adjusted to 3.0 using a 5% solution of ammonia water in the prepared catalyst suspension.

Comparative example  One

A final Mo-Bi composite metal oxide catalyst (catalyst G) was prepared in the same manner as in Example 1, except that the drying process was performed without a separate pH adjustment step (pH = 0.05).

Comparative example  2

Except for preparing a Mo-Bi-based composite metal oxide represented by the following Chemical Formula 3 by applying 7 g of potassium nitrate to a method of controlling the amount of alkali metals without a separate pH adjustment step (pH = 0.05) to the prepared catalyst suspension Then, a final Mo-Bi composite metal oxide catalyst (catalyst H) was prepared in the same manner as in Comparative Example 1. At this time, the composition ratio of the catalyst elements excluding oxygen is _{Mo 12 Bi 1 .2 Fe 1 .2} Co 5 K 0. ₁₅ .

Comparative example  3

Except for preparing a Mo-Bi-based composite metal oxide represented by the following formula (4) by applying 8.1 g of potassium nitrate to the amount of alkali metal without a separate pH adjustment step (pH = 0.05) to the prepared catalyst suspension Then, the final Mo-Bi composite metal oxide catalyst (catalyst I) was prepared in the same manner as in Comparative Example 1. At this time, the composition ratio of the catalyst elements excluding oxygen is _{Mo 12 Bi 1 .2 Fe 1 .2} Co 5 K 0. ₁₇ .

Comparative example  4

Except for preparing a Mo-Bi-based composite metal oxide represented by the following Chemical Formula 5 by applying 9.5 g of potassium nitrate to a method of controlling the amount of alkali metals without a separate pH adjustment step (pH = 0.05) to the prepared catalyst suspension. Then, a final Mo-Bi composite metal oxide catalyst (catalyst J) was prepared in the same manner as in Comparative Example 1. At this time, the composition ratio of the catalyst elements excluding oxygen is _{Mo 12 Bi 1 .2 Fe 1 .2} Co 5 K 0. _{20 was} .

Comparative example  5

A Mo-Bi-based composite metal oxide catalyst was prepared in the same manner as in Example 1 except that the pH of the suspension was adjusted to 3.5 by using a 5% solution of ammonia water in the prepared catalyst suspension, but the catalyst properties were severely modified. It was impossible to mold itself.

Experimental Example  One

An inner diameter of 1 inch and a length of 80 cm stainless steel reaction tube heated with molten nitrate was filled with 5 cm of inert alumina silica from the inlet to the outlet of the reaction gas, followed by Examples 1 to 6 and Comparative Examples 1 to 1 as a first stage catalyst. 30 cm of the catalyst prepared according to (catalysts A to J) were charged.

The reaction conditions may be adopted those generally used for producing (meth) acrylic acid and (meth) acrolein from reactants such as propylene by gas phase catalytic oxidation. For example, as a starting gas, it contains at least 4% by volume of reactants such as propylene, 10-20% by volume of molecular oxygen and 60-80% by volume of an inert gas serving as a diluent (e.g. nitrogen, carbon dioxide, steam, etc.). The gas mixture is contacted with a catalyst of the present invention at a temperature in the range from 250 to 500 ° C., a pressure in the range from 0.1 to 3 kg / cm ² G and a space velocity in the range from 300 to 5,000 hr ⁻¹ (STP) to carry out the intended reaction. . Analysis of the reactants and products was carried out using a gas chromatograph analyzer to determine the results of each catalytic reaction experiment.

For the first stage catalytic reaction as described above, the reactant (propylene) conversion and yield were calculated according to Formulas 1, 2, and 3 below.

[Equation 1]

[Equation 2]

[Equation 3]

Experimental results of the Mo-Bi-based composite metal oxide catalysts (catalysts A to J) prepared according to Examples 1 to 6 and Comparative Examples 1 to 4 are shown in Table 1 below.

division Suspension pH Alkali metals
Content (exponential h value) Propylene
Conversion rate
(%, 300 ℃) Acrylic acid +
Acrolein
Selectivity (mol%) Acrylic acid +
Acrolein
Yield (mol%) Example 1 (catalyst A) 0.50 0.1 86.38 93.59 80.84 Example 2 (catalyst B) 1.00 0.1 83.58 93.54 78.18 Example 3 (catalyst C) 1.50 0.1 79.57 94.56 75.24 Example 4 (catalyst D) 2.00 0.1 75.14 94.22 70.80 Example 5 (catalyst E) 2.50 0.1 70.08 96.63 67.02 Example 6 (catalyst F) 3.00 0.1 65.57 95.42 62.57 Comparative Example 1 (catalyst G) 0.05 0.1 93.60 97.31 86.96 Comparative Example 2 (catalyst H) 0.05 0.15 88.03 92.21 81.17 Comparative Example 3 (Catalyst I) 0.05 0.17 89.83 92.93 83.30 Comparative Example 4 (Catalyst J) 0.05 0.20 88.15 91.71 80.84

As shown in Table 1, the Mo-Bi-based composite metal oxides of Examples 1 to 6 prepared by adjusting the pH of the catalyst suspension in an optimal range according to the present invention are easily adjusted according to the pH change and have excellent characteristics. It can be seen that indicates. In particular, as the pH of the suspension is increased from 0.50 to 3.0, it can be seen that the yield according to the catalytic activity of the prepared Mo-Bi composite metal oxide is adjusted in a consistent direction from 80.84% to 62.57%. Accordingly, the present invention provides Mo- having an optimum range of catalytic activity according to reaction conditions such as the first and second stage catalyst configurations and temperature, so that (meth) acrylic acid and acrolein can be produced in high conversion and excellent yield. It can be seen that the Bi-based composite metal oxide can be prepared.

On the other hand, it can be seen that the composite metal oxide of Comparative Examples 1 to 4 prepared by only changing the alkali metal content without a separate pH control is unable to control the catalyst activity consistently. Particularly, when the alkali metal content is 5 g (h value 0.1) of potassium nitrate in Comparative Example 1 and 7 g of potassium nitrate (h value 0.15) is used in Comparative Example 2, the yield according to catalytic activity is 81.17% at 81.96%. Reduced to%. However, when using potassium nitrate 8.1 g (h value 0.17) in Comparative Example 3, the yield was increased to 83.30% according to the catalytic activity, and when using 9.5 g of potassium nitrate (h value 0.20) in Comparative Example 4 again. Reduced to 80.84%. Thus, it can be seen that when the alkali metal content is changed as in Comparative Examples 1 to 4, it is impossible to control the catalytic activity of the Mo-Bi composite metal oxide.

Experimental Example  2

Manufacturing example  1-6 and comparison Manufacturing example  One

Mo-Bi-based composite metal oxide catalysts (catalysts A to G) prepared according to Examples 1 to 6 and Comparative Example 1 were used as front and rear catalysts as shown in Table 2 below ( Metha) acrylic acid and (meth) acrolein were subjected to the preparation reaction.

At this time, the catalyst performance was verified through the catalyst filling (operation time 1,000 hours) and activity experiment as follows.

First, an inner diameter of 1 inch and a 3 m length stainless steel reaction tube heated with molten nitrate was filled with 150 mm of inert material alumina silica from the inlet to the outlet of the reaction gas, followed by Examples 1 to 6 and Comparative Example. The catalyst prepared according to 1 (catalysts A to G) was charged 2,800 mm in the manner shown in Table 2 below.

Particularly, Preparation Examples 1 to 6 used a catalyst having a controlled activity (catalysts A to F) as shear catalysts by adjusting the pH to an optimum range according to Examples 1 to 6, and separately using a conventional pH according to Comparative Example 1 A high activity catalyst (catalyst G), which was prepared without control and without activity control, was used as a post catalyst so that the front and post catalysts were arranged in the direction of increasing activity. However, in Comparative Example 1, both the shear catalyst and the post-catalyst were filled with a high activity catalyst (catalyst G) without activity control prepared without separate pH adjustment in a conventional manner according to Comparative Example 1.

The reaction test results of Preparation Examples 1 to 6 and Comparative Preparation Examples using Mo-Bi-based composite metal oxide catalysts (catalysts A to G) prepared according to Examples 1 to 6 and Comparative Example 1 are shown in Table 2 below. .

division Shear catalyst Postcatalyst Propylene conversion
(%, 300 ℃) Acrylic Acid + Acrolein
Yield (mol%) ingredient Filling
Length
(mm) ^* Filling
ratio
(%) ingredient Filling
Length
(mm) ^* Filling
ratio
(%) Production Example 1 Catalyst A 800 28.60 Catalyst G 2,000 71.40 96.24 89.40 Production Example 2 Catalyst B 800 28.60 Catalyst G 2,000 71.40 96.13 93.10 Production Example 3 Catalyst C 800 28.60 Catalyst G 2,000 71.40 95.84 92.50 Production Example 4 Catalyst D 1,000 35.70 Catalyst G 1,800 64.30 94.32 93.78 Production Example 5 Catalyst E 1,200 42.85 Catalyst G 1,600 57.20 94.12 91.64 Production Example 6 Catalyst F 1,500 53.57 Catalyst G 1,300 46.43 94.87 89.13 Comparative Preparation Example 1 Catalyst G 800 28.60 Catalyst G 2,000 71.40 96.75 88.13 ^* L / OD = 1, L: catalyst length, OD: catalyst outer diameter

As shown in Table 2, according to the present invention, by adjusting the pH of the catalyst suspension to an optimum range, the Mo-Bi-based composite metal oxide catalysts (catalysts A to F) of Examples 1 to 6, whose catalyst activity was adjusted, were sheared ( Front) Production Examples 1 to 6 used as catalysts show that the reaction yield is very good, with 89.13% to 93.78%. On the other hand, in the case of Comparative Preparation Example 1, in which the shear catalyst and the post-catalyst were both filled with the Mo-Bi-based composite metal oxide catalyst of Comparative Example 1 (catalyst G) prepared in a conventional manner without separate pH adjustment, the reaction yield was It can be seen that the drop significantly to 88.13%.

Thus, by using the Mo-Bi-based composite metal oxide catalyst (catalysts A to F) of Examples 1 to 6 in which the catalyst activity was adjusted by adjusting the pH of the catalyst suspension to an optimum range according to the present invention, a shear catalyst was prepared. In Examples 1 to 6, it can be seen that, as the activity control of the first stage catalyst inhibits the reaction of the hot spot site, it is possible to produce not only the thermal stability and high yield of acrylic acid but also the high load operation.

Claims (11)

In the manufacturing method of Mo-Bi-based composite metal oxide represented by the formula (1),
Molybdenum compounds; Bismuth compounds; Salts of at least one metal selected from the group consisting of Fe, Zn, Cr, Mn, Cu, Ru, Pd, Ag, and Ru; Salts of at least one metal selected from the group consisting of Co, Cd, Ta, Pt, and Ni; Dissolving a salt of at least one metal selected from the group consisting of Na, K, Li, Rb, Cs, Ca, Mg, Sr, and Ba in water to prepare a catalyst suspension,
Adding organic alkali to the catalyst suspension to adjust the pH of the catalyst suspension to 0.1 to 3.3, and
Drying the catalyst suspension
Method for producing a Mo-Bi-based composite metal oxide comprising:
[Formula 1]
Mo _a Bi _b M ¹ _c M ² _d M ³ _e M ⁴ _f M ⁵ _g M ⁶ _h O _i
In this formula,
Mo is molybdenum,
Bi is bismuth,
M ¹ is at least one element selected from the group consisting of W, Sb, As, P, Sn, and Pb,
M ² is at least one element selected from the group consisting of Fe, Zn, Cr, Mn, Cu, Pd, Ag, and Ru,
M ³ is at least one element selected from the group consisting of Co, Cd, Ta, Pt and Ni,
M ⁴ is at least one element selected from the group consisting of Al, Zr, V and Ce,
M ⁵ is at least one element selected from the group consisting of Se, Ga, Ti, Ge, Rh and Au,
M ⁶ is at least one element selected from the group consisting of Na, K, Li, Rb, Cs, Ca, Mg, Sr, and Ba,
a, b, c, d, e, f, g, h, and i represent the atomic ratio of each element,
When a = 12, b is 0.01-20, c is 0-20, d is 0.001-15, e is 0.001-20, f is 0-20, g is 0-10, h is 0.001-10, i is It is a numerical value determined according to the oxidation state of each component. The method of claim 1,
The catalyst suspension is added with a salt of a metal selected from at least one of the group consisting of W, Sb, As, P, Sn, Pb, Al, Zr, V, Ce, Se, Ga, Ti, Ge, Rh, and Au. Method for producing a Mo-Bi-based composite metal oxide comprising a. The method of claim 1,
Method for producing a Mo-Bi composite metal oxide having a pH of the catalyst suspension of 0.3 to 3.1. The method of claim 1,
The organic alkali is a method for producing a Mo-Bi composite metal oxide is an amine compound containing an alkyl group or an aryl group having 1 to 12 carbon atoms. The method of claim 1,
Method for producing a Mo-Bi-based composite metal oxide further comprising the step of firing the composite metal oxide at 300 to 600 ℃. Mo-Bi composite metal oxide prepared according to any one of claims 1 to 5, represented by the formula (1).
[Formula 1]
Mo _a Bi _b M ¹ _c M ² _d M ³ _e M ⁴ _f M ⁵ _g M ⁶ _h O _i
In this formula,
Mo is molybdenum,
Bi is bismuth,
M ¹ is at least one element selected from the group consisting of W, Sb, As, P, Sn, and Pb,
M ² is at least one element selected from the group consisting of Fe, Zn, Cr, Mn, Cu, Pd, Ag, and Ru,
M ³ is at least one element selected from the group consisting of Co, Cd, Ta, Pt and Ni,
M ⁴ is at least one element selected from the group consisting of Al, Zr, V and Ce,
M ⁵ is at least one element selected from the group consisting of Se, Ga, Ti, Ge, Rh and Au,
M ⁶ is at least one element selected from the group consisting of Na, K, Li, Rb, Cs, Ca, Mg, Sr, and Ba,
a, b, c, d, e, f, g, h, and i represent the atomic ratio of each element,
When a = 12, b is 0.01-20, c is 0-20, d is 0.001-15, e is 0.001-20, f is 0-20, g is 0-10, h is 0.001-10, i is It is a numerical value determined according to the oxidation state of each component. The method of claim 6,
Mo-Bi composite metal oxide used as a catalyst. The method of claim 6,
Mo-Bi composite metal oxide used as a catalyst for catalytic partial oxidation. A process for preparing (meth) acrylic acid and (meth) acrolein from at least one reactant selected from the group consisting of propylene, propane, isobutylene, t-butyl alcohol or methyl-t-butyl ether. A method for producing (meth) acrylic acid and (meth) acrolein using the Mo-Bi composite metal oxide according to any one of claims 8 as a catalyst. 10. The method of claim 9,
In filling the reactor with the Mo-Bi-based composite metal oxide catalyst, the catalyst on the reaction gas inlet side of the reactor is filled in the slurry solution at a higher pH condition than the catalyst on the reaction gas outlet side (meta ) Acrylic acid and (meth) acrolein production method. 10. The method of claim 9,
Method of producing (meth) acrylic acid and (meth) acrolein so that the Mo-Bi-based composite metal oxide catalyst is filled more than 20% of the total filling height.