WO2019013116A1

WO2019013116A1 - Method for manufacturing catalyst, method for manufacturing unsaturated carboxylic acid, method for manufacturing unsaturated aldehyde and unsaturated carboxylic acid, and method for manufacturing unsaturated carboxylic acid ester

Info

Publication number: WO2019013116A1
Application number: PCT/JP2018/025649
Authority: WO
Inventors: 充菅野; 拓朗渡邉; 浩一谷元; 正範新田
Original assignee: 三菱ケミカル株式会社
Priority date: 2017-07-10
Filing date: 2018-07-06
Publication date: 2019-01-17
Also published as: MY192580A; SA519410852B1; CN110809494B; KR102364540B1; CN110809494A; JPWO2019013116A1; JP6798617B2; KR20200026933A

Abstract

A catalyst is provided with which a target product can be manufactured with high selectivity. The present invention is a method for manufacturing a catalyst that is used when subjecting unsaturated aldehyde to gas-phase catalytic oxidation using molecular oxygen and manufacturing unsaturated carboxylic acid, the catalyst containing at least molybdenum and phosphorus, wherein the method for manufacturing the catalyst includes a step for exposing a catalyst precursor containing a nitrogen-containing component to a pressure exceeding atmospheric pressure, and firing the catalyst precursor.

Description

Method of producing catalyst, method of producing unsaturated carboxylic acid, method of producing unsaturated aldehyde and unsaturated carboxylic acid, and method of producing unsaturated carboxylic acid ester

The present invention relates to a method of producing a catalyst, a method of producing an unsaturated carboxylic acid, a method of producing an unsaturated aldehyde and an unsaturated carboxylic acid, and a method of producing an unsaturated carboxylic acid ester.

A number of studies have been made on the method of producing the catalyst. The catalyst is generally produced by preparing a raw material liquid such as an aqueous solution or an aqueous slurry containing each element constituting the catalyst, and drying and calcining the raw material liquid.

For example, Patent Documents 1 to 3 describe the baking using a gas containing ammonia or water vapor, Patent Document 4 describes baking using a non-oxidative gas, and Patent Document 5 using a gas containing an oxygen-containing organic compound. There is. Moreover, in patent document 6, it describes about the baking method which consists of several processes which changed the gas to be used, and a calcination temperature. Patent Document 7 describes the gas flow rate to the catalyst precursor.

JP-A-58-61833 JP-A-58-67643 Japanese Patent Application Laid-Open No. 58-79545 JP-A-59-66349 JP-A-59-69148 JP 2012-245432 A JP, 2009-213969, A

However, the catalyst produced by the method described in Patent Documents 1 to 7 is a reaction for producing an unsaturated carboxylic acid by vapor phase catalytic oxidation of unsaturated aldehyde with molecular oxygen, or propylene, isobutylene, primary Gas-phase catalytic oxidation of at least one member selected from the group consisting of butyl alcohol, tertiary butyl alcohol and methyl tertiary butyl ether with molecular oxygen to produce corresponding unsaturated aldehydes and unsaturated carboxylic acids When used for the reaction, there is a problem that the selectivity of the desired product is not sufficient. For this reason, development of the manufacturing method of the catalyst which can manufacture a target product with higher selectivity is desired. The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a catalyst capable of producing a target product with high selectivity.

The above problems are solved by the following present inventions [1] to [16].

[1] A method for producing a catalyst containing at least molybdenum and phosphorus, which is used when producing unsaturated carboxylic acid by vapor phase catalytic oxidation of unsaturated aldehyde with molecular oxygen, which is a catalyst precursor containing a nitrogen-containing component A method for producing a catalyst, comprising the steps of calcining a body by applying pressure above atmospheric pressure.

[2] At least one selected from the group consisting of propylene, isobutylene, primary butyl alcohol, tertiary butyl alcohol and methyl tertiary butyl ether by gas phase catalytic oxidation with molecular oxygen and corresponding A method for producing a catalyst containing at least molybdenum and bismuth, which is used in producing unsaturated aldehyde and unsaturated carboxylic acid, wherein a catalyst precursor containing a nitrogen-containing component is calcined by exposing to pressure exceeding atmospheric pressure. A method of producing a catalyst comprising the steps.

[3] The method for producing a catalyst according to [1] or [2], wherein the unsaturated aldehyde is acrolein or methacrolein.

[4] When calcining the catalyst precursor, the catalyst according to any one of [1] to [3] is calcined under a gas flow of at least one selected from an oxygen-containing gas and an inert gas Method.

[5] The method for producing a catalyst according to any one of [1] to [4], wherein the pressure is 10 kPa (G) or more and 100 kPa (G) or less.

[6] The method for producing a catalyst according to [5], wherein the pressure is 20 kPa (G) or more and 80 kPa (G) or less.

[7] The method for producing a catalyst according to any one of [1] to [6], wherein the highest temperature in the calcination is 300 ° C. or more and 700 ° C. or less.

[8] The method for producing a catalyst according to [7], wherein the maximum value of the temperature in the calcination is 350 ° C. or more and 400 ° C. or less.

[9] The method for producing a catalyst according to any one of [1] to [8], wherein the nitrogen-containing component is at least one selected from the group consisting of ammonium roots and nitrate roots.

[10] The method for producing a catalyst according to [1], wherein the catalyst precursor contains a heteropoly acid structure.

[11] The method for producing a catalyst according to [10], wherein the heteropoly acid structure is a Keggin heteropoly acid structure.
[12] A method for producing an unsaturated carboxylic acid, which comprises producing an unsaturated carboxylic acid by gas phase catalytic oxidation of unsaturated aldehyde with molecular oxygen in the presence of a catalyst produced by the method according to [1].

[13] A method for producing an unsaturated carboxylic acid, comprising: preparing a catalyst by the method according to [13]; Method.
[14] [2] at least one member selected from the group consisting of propylene, isobutylene, primary butyl alcohol, tertiary butyl alcohol and methyl tertiary butyl ether in the presence of the catalyst produced by the method according to [14] [2] A method for producing unsaturated aldehydes and unsaturated carboxylic acids, which comprises the step of vapor phase catalytic oxidation of H 2 O with molecular oxygen to produce corresponding unsaturated aldehydes and unsaturated carboxylic acids.

[15] A catalyst is prepared by the method described in [2], and is selected from the group consisting of propylene, isobutylene, primary butyl alcohol, tertiary butyl alcohol and methyl tertiary butyl ether in the presence of the catalyst A method for producing unsaturated aldehydes and unsaturated carboxylic acids, wherein at least one is subjected to gas phase catalytic oxidation with molecular oxygen to produce corresponding unsaturated aldehydes and unsaturated carboxylic acids.

[16] A method for producing an unsaturated carboxylic acid ester, which esterifies the unsaturated carboxylic acid produced by the method according to any one of [12] to [15].

According to the present invention, it is possible to provide a catalyst capable of producing a target product with high selectivity.

[Method of producing catalyst]
The first embodiment of the process for producing a catalyst according to the present invention is a catalyst comprising at least molybdenum and phosphorus, which is used in the vapor phase catalytic oxidation of unsaturated aldehyde with molecular oxygen to produce unsaturated carboxylic acid. It is a manufacturing method. The method includes the steps of calcinating a catalyst precursor containing a nitrogen-containing component by applying a pressure above atmospheric pressure.

In addition, the second embodiment of the process for producing a catalyst according to the present invention comprises at least one selected from the group consisting of propylene, isobutylene, primary butyl alcohol, tertiary butyl alcohol and methyl tertiary butyl ether. This is a method for producing a catalyst containing at least molybdenum and bismuth, which is used in producing gas phase catalytic oxidation with molecular oxygen to produce the corresponding unsaturated aldehyde and unsaturated carboxylic acid. The method includes the steps of calcinating a catalyst precursor containing a nitrogen-containing component by applying a pressure above atmospheric pressure.

In the method according to the present invention, attention is paid to the pressure at the time of calcination of the catalyst precursor, and the desired product is obtained with high selectivity by calcinating the catalyst precursor containing the nitrogen-containing component under a pressure exceeding atmospheric pressure. A producible catalyst can be obtained. The reason is considered as follows. That is, the structure of the catalyst precursor changes in the process of desorption of the nitrogen-containing component during the calcination, and a catalyst active point preferable for the intended reaction is formed. At this time, desorption of the nitrogen-containing component is suppressed by exposing the catalyst precursor to a pressure higher than atmospheric pressure. As a result, it is presumed that the structural change of the catalyst occurs at a slower rate than in the case of calcining under a pressure less than atmospheric pressure, and a homogeneous active point structure is formed by the catalyst surface. In the prior art, the effects of pressure at the time of firing have not been studied in detail.

The process according to the present invention is a catalyst containing at least molybdenum and phosphorus (hereinafter referred to as a catalyst for producing unsaturated carboxylic acid, which is used when producing unsaturated carboxylic acid by gas phase catalytic oxidation of unsaturated aldehyde with molecular oxygen to produce unsaturated carboxylic acid Also used in the manufacture of By carrying out the reaction using the catalyst, unsaturated carboxylic acids can be produced with higher selectivity. The unsaturated aldehyde is preferably acrolein or methacrolein because it can produce acrylic acid or methacrylic acid with higher selectivity. In addition, it is preferable that the catalyst contains a heteropoly acid structure, particularly a Keggin-type heteropoly acid structure, because unsaturated carboxylic acid can be produced with higher selectivity.

In the method according to the present invention, at least one selected from the group consisting of propylene, isobutylene, primary butyl alcohol, tertiary butyl alcohol and methyl tertiary butyl ether is subjected to vapor phase catalytic oxidation with molecular oxygen Used for producing a catalyst containing at least molybdenum and bismuth (hereinafter also referred to as a catalyst for producing unsaturated aldehyde and unsaturated carboxylic acid) used in producing the corresponding unsaturated aldehyde and unsaturated carboxylic acid. Be By performing the reaction using the catalyst, unsaturated aldehydes and unsaturated carboxylic acids can be produced with higher selectivity. The unsaturated aldehyde is preferably acrolein or methacrolein, and the unsaturated carboxylic acid is preferably acrylic acid or methacrylic acid from the viewpoint of selectivity.

The composition of the catalyst obtained by the method according to the present invention is not particularly limited, but when the catalyst is the catalyst for producing unsaturated carboxylic acid, from the viewpoint of being able to produce unsaturated carboxylic acid with higher selectivity, The catalyst preferably has a composition represented by the following formula (1).

P _α1 Mo _α2 V _α3 Cu _α4 A _α5 E _α6 G _α7 O _α8 (1)
In formula (1), P, Mo, V, Cu and O are element symbols which show phosphorus, molybdenum, vanadium, copper and oxygen, respectively. A represents at least one element selected from the group consisting of antimony, bismuth, arsenic, germanium, zirconium, tellurium, silver, selenium, silicon, tungsten and boron. E represents at least one element selected from the group consisting of potassium, rubidium, cesium, thallium, magnesium and barium. G is at least one selected from the group consisting of iron, zinc, chromium, calcium, strontium, tantalum, cobalt, nickel, manganese, titanium, tin, lead, niobium, indium, sulfur, palladium, gallium, cerium and lanthanum Indicates an element. α1 to α8 represent atomic ratios of respective elements, and when α2 = 12, α1 = 0.5 to 3, α3 = 0.01 to 3, α4 = 0.01 to 2, α5 = 0 to 3, preferably 0 .01 to 3, .alpha.6 = 0.01 to 3, .alpha.7 = 0 to 4, and .alpha.8 is an atomic ratio of oxygen necessary to satisfy the valences of the respective elements.

When the catalyst obtained by the method according to the present invention is the catalyst for producing the above-mentioned unsaturated aldehyde and unsaturated carboxylic acid, the unsaturated aldehyde and the unsaturated carboxylic acid can be produced at a higher selectivity because The catalyst preferably has a composition represented by the following formula (2).

_{_{_{_{Mo α9 Bi α10 Fe α11 X α12}}}} A 'α13 E' α14 G 'α15 Si α16 O α17 (2)
In formula (2), Mo, Bi, Fe, Si and O are element symbols showing molybdenum, bismuth, iron, silicon and oxygen, respectively. X represents at least one element selected from the group consisting of cobalt and nickel. A ′ represents at least one element selected from the group consisting of chromium, lead, manganese, calcium, magnesium, niobium, silver, barium, tin, tantalum and zinc. E ′ represents at least one element selected from the group consisting of phosphorus, boron, sulfur, selenium, tellurium, cerium, tungsten, antimony and titanium. G ′ represents at least one element selected from the group consisting of lithium, sodium, potassium, rubidium, cesium and thallium. α9 to α17 represent atomic ratios of respective elements, and when α9 = 12, α10 = 0.01 to 3, α11 = 0.01 to 5, α12 = 1 to 12, α13 = 0 to 8, α14 = 0 to 5 .Alpha.15 = 0.001-2 and .alpha.16 = 0-20, and .alpha.17 is an atomic ratio of oxygen necessary to satisfy the valences of the respective elements.

The method for producing a catalyst according to the present invention is not particularly limited as long as it includes a step of firing a catalyst precursor containing a nitrogen-containing component by applying a pressure exceeding atmospheric pressure (hereinafter also referred to as a firing step). However, the method comprises the steps of preparing a raw material liquid containing each element constituting the catalyst (hereinafter also referred to as raw material liquid preparation step) and drying the raw material liquid to obtain a catalyst precursor (hereinafter drying step). It is preferable from the viewpoint of obtaining a catalyst capable of producing the target product with higher selectivity, which also includes the calcination step). In addition, the method may include a step of forming a catalyst precursor (hereinafter also referred to as a forming step), as necessary, between the drying step and the firing step.

Raw material liquid preparation process
At a raw material liquid preparation process, the raw material liquid containing each element which comprises a catalyst is prepared. In the production of the catalyst for unsaturated carboxylic acid production, the raw material liquid contains at least molybdenum and phosphorus. Further, in the production of the catalyst for producing the unsaturated aldehyde and the unsaturated carboxylic acid, the raw material liquid contains at least molybdenum and bismuth. When the raw material liquid contains these elements, it is possible to produce a catalyst for unsaturated carboxylic acid production with a high selectivity of the desired product, or a catalyst for unsaturated aldehyde and unsaturated carboxylic acid production. About the kind and ratio of each element which comprise a catalyst, when this catalyst is a catalyst for unsaturated carboxylic acid manufacture, it can be set as the element and atomic ratio shown, for example by said Formula (1). When the catalyst is a catalyst for producing unsaturated aldehyde and unsaturated carboxylic acid, for example, the element and atomic ratio can be set to the formula (2).

The preparation method of the raw material solution is not particularly limited, but a method of preparing a slurry-like raw material solution by charging the raw material of each element into water, heating to 30 to 100 ° C. and stirring is preferable. The amount of water used is preferably 200 to 1000 parts by mass with respect to a total of 100 parts by mass of the raw material of each element.

It does not specifically limit as a raw material of each element, The oxide of each element, nitrate, carbonate, ammonium salt etc. can be selected suitably, and can be used. For example, as a raw material of molybdenum, molybdic acid, molybdenum trioxide, ammonium paramolybdate and the like can be used, and molybdic acid and molybdenum trioxide are preferable. As a raw material of phosphorus, orthophosphoric acid, phosphorus pentoxide, ammonium phosphate etc. can be used. As a raw material of vanadium, ammonium metavanadate, vanadium pentoxide etc. can be used. In addition, copper nitrate, copper sulfate, copper carbonate and the like can be used as a raw material of copper. Further, as a raw material of bismuth, bismuth nitrate, bismuth oxide, bismuth acetate, bismuth hydroxide and the like can be used. One of these raw materials may be used, or two or more thereof may be used in combination.

In the method according to the present invention, since the catalyst precursor contains a nitrogen-containing component, the raw material liquid preferably contains a nitrogen-containing component. Examples of the nitrogen-containing component include ammonium roots, nitrate roots, nitrogen-containing heterocycles and the like, but at least one selected from the group consisting of ammonium roots and nitrate roots, the viewpoint of selectivity of the target product It is preferable from Here, the ammonium root in the present invention is a generic name of ammonia (NH ₃ ) which can be ammonium ion (NH ₄ ⁺ ), and ammonium contained in ammonium-containing compounds such as ammonium salts. Examples of the ammonium-containing compound include ammonium carbonate, ammonium bicarbonate, ammonium nitrate, ammonium acetate, ammonium vanadate, ammonium salts of elements constituting a catalyst, and the like. Further, the nitrate root in the present invention is a general term for nitrogen oxide ions such as nitrate ion (NO ₃ ⁻ ) and nitrite ion (NO ₂ ⁻ ). As a nitrate root, the nitrate ion contained in the nitrate of a catalyst structural element is mentioned, for example. One of these may be used, or two or more may be used in combination. In addition, you may make it a nitrogen-containing component be contained in a raw material liquid by using ammonium salt and nitrate of each element as a raw material of each said element.

The preparation scale of the raw material liquid is not particularly limited, but the lower limit of the amount of the raw material of the main element is preferably 100 g or more, and more preferably 1 kg or more. The upper limit is preferably 10 t or less, more preferably 1 t or less. By setting such a scale, a good raw material solution can be stably prepared.

(Drying process)
In the drying step, the raw material liquid obtained in the raw material liquid preparation step is dried to obtain a catalyst precursor. Although there is no restriction | limiting in particular in the drying method of a raw material liquid, For example, the evaporation-to-dryness method, spray-drying method, drum drying method, flash drying method etc. are mentioned. There are no particular restrictions on the type and type of dryer used for drying, the temperature at the time of drying, the atmosphere, and the like. By changing the drying conditions, physical properties such as flowability and moldability of the catalyst precursor can be controlled, so it is preferable to set conditions according to the purpose.

When the method according to the present invention is used for the production of the catalyst for unsaturated carboxylic acid production, the catalyst precursor obtained preferably has a heteropolyacid structure from the viewpoint of producing unsaturated carboxylic acid with higher selectivity. It is more preferable to include a Keggin type heteropoly acid structure. In addition, it can be confirmed by measuring a catalyst precursor by infrared absorption analysis whether the catalyst precursor contains a heteropoly acid structure (Keggin type heteropoly acid structure). For example, when the catalyst precursor contains a Keggin-type heteropolyacid structure, the obtained infrared absorption spectrum has characteristic peaks in the vicinity of 1060, 960, 870, 780 cm ^-1 .

The amount of the nitrogen-containing component contained in the obtained catalyst precursor is not particularly limited, and can be, for example, 0.5 to 7.0% by mass.

(Molding process)
In the forming step, the catalyst precursor obtained in the drying step is formed. There is no particular limitation on the molding method, and known dry and wet molding methods can be applied. For example, tablet molding, press molding, extrusion molding, granulation molding and the like can be mentioned. The shape of the molded article is also not particularly limited, and examples thereof include a cylindrical shape, a ring shape, and a spherical shape. Further, at the time of molding, it is preferable to mold only the catalyst precursor without adding a carrier or the like to the catalyst precursor, but if necessary, known additives such as graphite and talc may be added.

(Firing process)
In the calcination step, the obtained catalyst precursor containing a nitrogen-containing component is calcined by being exposed to a pressure exceeding atmospheric pressure. The pressure to which the catalyst precursor is exposed is preferably 10 kPa (G) or more, more preferably 20 kPa (G) or more, and still more preferably 30 kPa (G) or more. The pressure is preferably 100 kPa (G) or less, more preferably 80 kPa (G) or less, and still more preferably 70 kPa (G) or less. By the pressure being 10 kPa (G) or more, desorption of the nitrogen-containing component is suppressed, and a homogeneous active site structure is formed by the catalyst surface. In addition, when the pressure is 100 kPa (G) or less, desorption of the nitrogen-containing component from the catalyst precursor is not excessively inhibited, and a decrease in the reaction rate of the catalyst can be suppressed. "KPa (G)" indicates a gauge pressure, and the atmospheric pressure + gauge pressure is the actual pressure.

In addition, let the said pressure be the pressure in the temperature fixed process from temperature rising process of a baking process. Moreover, the value of the pressure is a value obtained by measuring any one point in the container when firing is performed in a container having no spatial distribution of pressure, and the pressure may be generated when flowing gas in a tubular firing container, etc. In systems where there is a spatial distribution of, the pressure is at the lowest point in the system, such as the pressure at the firing gas outlet. Moreover, the inside of the system here means the range from the baking gas inlet of a baking container to a baking gas outlet. The method for measuring the pressure in the system is not particularly limited, but can be measured, for example, by providing a pressure gauge upstream of the calcination gas outlet and as close as possible to the calcination gas outlet. Further, the method of increasing the pressure is not particularly limited, but in the case of firing under gas flow as described later, for example, a pipe for the gas outlet is extended, a pressure control valve is provided at the gas outlet This can be achieved by, for example, throttling the valve or connecting the gas outlet to a trap tank filled with water or the like.

Although there is no restriction | limiting in particular in the kind of atmospheric gas at the time of baking a catalyst precursor, Oxygen-containing gas, such as air, or inert gas is preferable. Here, the inert gas refers to a gas which does not reduce the catalytic activity, and includes nitrogen, carbon dioxide gas, helium, argon and the like. As said gas, air, nitrogen, the mixed gas of oxygen and air, or these mixed gas are more preferable, and air is further more preferable. Also, the gas may include water vapor. The content of water vapor is preferably 0.01 to 5% by volume based on the whole gas to be circulated, and more preferably, the lower limit is 0.05% by volume or more and the upper limit is 2% by volume or less. There is no particular limitation on the method of supplying the atmosphere gas at the time of firing, and the inside of the firing container may be filled with the atmosphere gas, and then the container may be closed and fired. Gas flow always supplying the atmosphere gas into the firing container Although baking may be performed below, baking under gas flow is preferable from the viewpoint of catalyst activity.

The lower limit of the highest temperature in the firing is preferably 300 ° C. or more, more preferably 320 ° C. or more, still more preferably 350 ° C. or more, and particularly preferably 370 ° C. or more. The upper limit of the maximum temperature is preferably 700 ° C. or less, more preferably 450 ° C. or less, still more preferably 400 ° C. or less, and particularly preferably 390 ° C. or less. When the calcination temperature is 300 ° C. or more, desorption of the nitrogen-containing component is promoted, and when the calcination temperature is 700 ° C. or less, it is possible to suppress the decrease in specific surface area due to the thermal decomposition or sintering of the catalyst. Here, the highest temperature means the temperature of the highest temperature portion of the temperature of the inner wall surface of the calcining vessel in contact with the catalyst precursor. Although the measuring method in particular of temperature is not restrict | limited, The method of using a thermocouple is preferable.

A preferable range of the residual amount of the nitrogen-containing component in the obtained catalyst can be, for example, 0.001 to 1 mmol / g per unit mass of catalyst although it depends on the use method of the catalyst.

The shape of the firing vessel is not particularly limited, and may be box-shaped or tubular, but it is preferable to use a tubular firing vessel having a cross-sectional area of 2 to 100 cm ² . By the cross-sectional area being 2 cm ² or more, industrial productivity is improved. Moreover, temperature control becomes easy and generation | occurrence | production of a hot spot can be suppressed because this cross-sectional area is 100 cm < ² > or less.

[Method for producing unsaturated carboxylic acid]
The unsaturated aldehyde is gas phase catalytically oxidized with molecular oxygen in the presence of the catalyst produced by the process according to the invention. That is, the method for producing unsaturated carboxylic acid according to the present invention comprises the steps of producing a catalyst by the method according to the present invention, and performing catalytic vapor phase oxidation of unsaturated aldehyde with molecular oxygen in the presence of the catalyst Have. By using the catalyst produced by the method according to the present invention, unsaturated carboxylic acids can be produced with higher selectivity than in the prior art. As unsaturated aldehyde, acrolein or methacrolein is preferable, and methacrolein is more preferable. Hereinafter, the case where methacrolein is used as the unsaturated aldehyde will be described. In the method, for example, by contacting a catalyst with a raw material gas containing methacrolein and molecular oxygen, methacrolein is gas phase catalytically oxidized by molecular oxygen to obtain methacrylic acid.

The concentration of the raw material compound in the raw material gas is not limited and can be set to any concentration, but it is preferably 1 to 20% by volume, the lower limit is 3% by volume or more, and the upper limit is 10% by volume or less. The molecular oxygen concentration in the raw material gas is preferably 0.5 to 4.0 mol with respect to 1 mol of the raw material compound, and the lower limit is particularly preferably 1.0 mol or more and the upper limit is more preferably 3.0 mol or less. In addition, an inert gas such as nitrogen or carbon dioxide gas may be added to the source gas for dilution, or steam may be added. The reaction pressure can be set in the range from atmospheric pressure to several hundreds kPa (G). The reaction temperature is preferably 230 to 450 ° C. from the viewpoint of the yield of the desired product, and the lower limit is particularly preferably 250 ° C. or more and the upper limit is more preferably 400 ° C. or less.

[Method for producing unsaturated aldehyde and unsaturated carboxylic acid]
At least one selected from the group consisting of propylene, isobutylene, primary butyl alcohol, tertiary butyl alcohol and methyl tertiary butyl ether in the presence of the catalyst produced by the process according to the invention, by means of molecular oxygen Gas phase catalytic oxidation. That is, the method for producing unsaturated aldehyde and unsaturated carboxylic acid according to the present invention comprises the steps of producing a catalyst by the method according to the present invention, propylene, isobutylene, primary butyl alcohol, Vapor phase catalytic oxidation of at least one member selected from the group consisting of secondary butyl alcohol and methyl tertiary butyl ether with molecular oxygen. By using the catalyst produced by the method according to the present invention, unsaturated aldehydes and unsaturated carboxylic acids can be produced with higher selectivity than conventional. The unsaturated aldehyde is preferably acrolein or methacrolein, and more preferably methacrolein. The unsaturated carboxylic acid is preferably acrylic acid or methacrylic acid, and more preferably methacrylic acid. The conditions of the gas phase catalytic oxidation reaction can be the same as the method for producing the unsaturated carboxylic acid.

[Method for producing unsaturated carboxylic acid ester]
The method for producing an unsaturated carboxylic acid ester according to the present invention esterifies the unsaturated carboxylic acid obtained by the method according to the present invention. According to the method, gas phase catalytic oxidation of unsaturated aldehydes or at least one gas phase selected from the group consisting of propylene, isobutylene, primary butyl alcohol, tertiary butyl alcohol and methyl tertiary butyl ether Unsaturated carboxylic acid esters can be obtained using unsaturated carboxylic acids obtained by catalytic oxidation. Examples of the alcohol to be reacted with the unsaturated carboxylic acid include methanol, ethanol, isopropanol, n-butanol, isobutanol and the like. Examples of the unsaturated carboxylic acid ester to be obtained include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate and butyl (meth) acrylate. The reaction can be carried out in the presence of an acidic catalyst such as a sulfonic acid type cation exchange resin. The reaction temperature is preferably 50 to 200 ° C.

Hereinafter, the present invention will be described in detail by way of examples and comparative examples, but the present invention is not limited to these examples. "Part" in an Example and a comparative example means a mass part. The molar ratio of the catalyst composition was calculated by analyzing the component in which the catalyst was dissolved in aqueous ammonia by ICP emission analysis.

The analysis of the source gases and products in the production of methacrylic acid was carried out using gas chromatography. From the results of gas chromatography, the conversion of methacrolein and the selectivity of methacrylic acid were determined by the following formula.

Methacrolein reaction rate (%) = (R / F) × 100
Methacrylic acid selectivity (%) = (P / R) × 100
In the formula, F is the number of moles of methacrolein supplied per unit time, R is the number of moles of methacrolein reacted in unit time, and P is the number of moles of methacrylic acid generated per unit time.

The selectivity of methacrylic acid changes with the conversion of methacrolein. Therefore, as for the selectivity of methacrylic acid in the gas phase catalytic oxidation reaction using each catalyst, it is preferable to compare the reaction rates of methacrolein with the same value. Therefore, in the following examples and comparative examples, the contact time is changed by appropriately adjusting the amount of the catalyst used for the reaction under a constant reaction gas flow rate, and the reaction rate of methacrolein is equalized to about 40%. Indicates

Example 1
(1) Raw material liquid preparation process 100 parts of molybdenum trioxide, 4.06 parts of ammonium metavanadate, 6.67 parts of 85 mass% phosphoric acid, 0.84 parts of antimony trioxide and copper nitrate 2.80 to pure water 400 parts I added a department. This was made into a slurry while stirring, and the obtained slurry was heated at 90 ° C. for 3 hours. While maintaining this at 90 ° C., a solution of 11.3 parts of cesium carbonate dissolved in 40.3 parts of pure water was added and held for 30 minutes. Then, a solution of 8.34 parts of ammonium carbonate dissolved in 37.5 parts of pure water was added. Subsequently, the raw material liquid was obtained by hold | maintaining 90 degreeC for 30 minutes.

(2) Drying Step The obtained raw material solution was heated at 101 ° C. and evaporated to dryness with stirring. Thereafter, the obtained solid was dried at 90 ° C. for 16 hours to obtain a catalyst precursor. The resulting catalyst precursor contained a Keggin-type heteropolyacid structure. Further, the composition except oxygen of the catalyst precursor was _{_{_{_{Mo 12 V 0.6 P 1.0 Sb 0.1}}}} Cu 0.2 Cs 1.2 (NH 4) 3.0.

(3) Forming Step The obtained catalyst precursor was formed into a ring shape having an outer diameter of 5 mm, an inner diameter of 2 mm and a length of 5 mm by a tablet forming machine.

(4) Firing Step The molded product of the obtained catalyst precursor is filled in a stainless steel pipe having an inner diameter of 27.5 mm and a length of 6 m, and the catalyst precursor is calcined at 380 ° C. under an air flow of space velocity 370 h ⁻¹ . I got a catalyst. At this time, the baking gas outlet was connected to an exhaust gas component trap tank filled with water, and the pressure in the main baking step was 64 kPa (G). The holding time at 380 ° C. during firing was 16 hours. In firing, the maximum temperature was 380.degree. From the obtained catalyst, a nitrogen-containing component of 0.001 to 1.0 mmol / g was detected per unit mass of the catalyst.

The obtained catalyst was charged in a reaction tube, a reaction gas was introduced, and methacrylic acid was produced by gas phase catalytic oxidation under the following reaction conditions. The results are shown in Table 1.

(Reaction conditions)
Reaction gas: Mixed gas of 4% by volume of methacrolein, 10% by volume of oxygen, 15% by volume of steam and 71% by volume of nitrogen Reaction temperature: 310 ° C.
Reaction pressure: 101 kPa (G)
Contact time: 1.8 seconds.

Comparative Example 1
By reducing the amount of water in the exhaust gas component trap tank connected to the calcining gas outlet than in Example 1, the pressure in the calcining step was set to 0 kPa (G), and the catalyst precursor was calcined at 380 ° C. for 12 hours A catalyst was produced in the same manner as Example 1 except for the following. In addition, the reaction was carried out in the same manner as in Example 1 except that the contact time was changed to 1.5 seconds using the obtained catalyst. The results are shown in Table 1.

Comparative Example 2
The catalyst was prepared in the same manner as in Example 1 except that the pressure in the calcination step was set to 0 kPa (G) by reducing the amount of water in the exhaust gas component trap tank connected to the calcining gas outlet than in Example 1. Manufactured. In addition, the reaction was performed in the same manner as in Example 1 except that the contact time was changed to 1.2 seconds using the obtained catalyst. The results are shown in Table 1.

Example 2
A catalyst was produced in the same manner as in Example 1 except that a pressure control valve was provided at the calcination gas outlet, the pressure in the calcination step was 64 kPa (G), and the catalyst precursor was calcined at 382 ° C. for 16 hours. In addition, the reaction was carried out in the same manner as in Example 1 except that the contact time was changed to 1.7 seconds using the obtained catalyst. The results are shown in Table 1.

[Example 3]
By reducing the amount of water in the exhaust gas component trap tank connected to the calcining gas outlet than in Example 1, the pressure in the calcining step was 54 kPa (G), and the catalyst precursor was calcined at 382 ° C. for 14 hours A catalyst was produced in the same manner as Example 1 except for the following. In addition, the reaction was carried out in the same manner as in Example 1 except that the contact time was changed to 1.7 seconds using the obtained catalyst. The results are shown in Table 1.

Example 4
A catalyst was produced in the same manner as in Example 2 except that the pressure in the firing step was changed to 10 kPa (G) by the pressure control valve and the catalyst precursor was fired at 380 ° C. for 16 hours. In addition, the reaction was carried out in the same manner as in Example 1 except that the contact time was changed to 1.4 seconds using the obtained catalyst. The results are shown in Table 1.

[Example 5]
A catalyst was produced in the same manner as in Example 4 except that the pressure in the firing step was changed to 30 kPa (G) by the pressure control valve. In addition, the reaction was carried out in the same manner as in Example 1 except that the contact time was changed to 1.5 seconds using the obtained catalyst. The results are shown in Table 1.

As shown in Table 1, in Examples 1 to 5 in which the catalyst was produced by the method according to the present invention, methacrylic acid was able to be produced with a high selectivity as compared with Comparative Examples 1 and 2.

Claims

A method for producing a catalyst containing at least molybdenum and phosphorus, which is used in producing unsaturated carboxylic acid by gas phase catalytic oxidation of unsaturated aldehyde with molecular oxygen,
A method for producing a catalyst, comprising the step of calcining a catalyst precursor containing a nitrogen-containing component by applying pressure above atmospheric pressure.
Gas-phase catalytic oxidation of at least one member selected from the group consisting of propylene, isobutylene, primary butyl alcohol, tertiary butyl alcohol and methyl tertiary butyl ether with molecular oxygen, and the corresponding unsaturated aldehydes And a method for producing a catalyst containing at least molybdenum and bismuth, which is used in producing unsaturated carboxylic acid,
A method for producing a catalyst, comprising the step of calcining a catalyst precursor containing a nitrogen-containing component by applying pressure above atmospheric pressure.
The method for producing a catalyst according to claim 1 or 2, wherein the unsaturated aldehyde is acrolein or methacrolein.
The method for producing a catalyst according to any one of claims 1 to 3, wherein the catalyst precursor is calcined under at least one gas flow selected from an oxygen-containing gas and an inert gas when the catalyst precursor is calcined.
The method according to any one of claims 1 to 4, wherein the pressure is 10 kPa (G) or more and 100 kPa (G) or less.
The method for producing a catalyst according to claim 5, wherein the pressure is 20 kPa (G) or more and 80 kPa (G) or less.
The method for producing a catalyst according to any one of claims 1 to 6, wherein the maximum value of the temperature in the calcination is 300 ° C or more and 700 ° C or less.
The method for producing a catalyst according to claim 7, wherein the maximum value of the temperature in the calcination is 350 ° C or more and 400 ° C or less.
The method for producing a catalyst according to any one of claims 1 to 8, wherein the nitrogen-containing component is at least one selected from the group consisting of ammonium roots and nitrate roots.
The method for producing a catalyst according to claim 1, wherein the catalyst precursor comprises a heteropoly acid structure.
The method for producing a catalyst according to claim 10, wherein the heteropoly acid structure is a Keggin heteropoly acid structure.
A method for producing an unsaturated carboxylic acid, which comprises subjecting an unsaturated aldehyde to gas phase catalytic oxidation with molecular oxygen in the presence of a catalyst produced by the method according to claim 1 to produce an unsaturated carboxylic acid.
A method for producing an unsaturated carboxylic acid, comprising producing a catalyst by the method according to claim 1 and catalytically oxidizing the unsaturated aldehyde with molecular oxygen in the presence of the catalyst to produce an unsaturated carboxylic acid.
A molecule of at least one selected from the group consisting of propylene, isobutylene, primary butyl alcohol, tertiary butyl alcohol and methyl tertiary butyl ether in the presence of the catalyst produced by the method according to claim 2 A process for producing unsaturated aldehydes and unsaturated carboxylic acids, which comprises the step of vapor phase catalytic oxidation with oxygen to produce corresponding unsaturated aldehydes and unsaturated carboxylic acids.
A catalyst is produced by the method according to claim 2, and at least one selected from the group consisting of propylene, isobutylene, primary butyl alcohol, tertiary butyl alcohol and methyl tertiary butyl ether in the presence of the catalyst. A method for producing unsaturated aldehydes and unsaturated carboxylic acids, which comprises the step of vapor phase catalytic oxidation of H 2 O with molecular oxygen to produce corresponding unsaturated aldehydes and unsaturated carboxylic acids.
The manufacturing method of the unsaturated carboxylic acid ester which esterifies the unsaturated carboxylic acid manufactured by the method of any one of Claims 12-15.