WO2007032228A1

WO2007032228A1 - Methods for recovery of molybdenum and process for preparation of catalysts

Info

Publication number: WO2007032228A1
Application number: PCT/JP2006/317548
Authority: WO
Inventors: Tomomasa Tatsumi; Hiroyuki Naitou; Toru Kuroda
Original assignee: Mitsubishi Rayon Co., Ltd.
Priority date: 2005-09-16
Filing date: 2006-09-05
Publication date: 2007-03-22
Also published as: JPWO2007032228A1

Abstract

The invention aims at providing methods for recovering molybdenum in a state usable as the raw material in the production of catalysts from a molybdenum-containing substance and a process for producing catalysts by use of the recovered molybdenum. The recovery of molybdenum according to the invention is conducted either by using a molybdenum-containing substance further containing bismuth or vanadium as the additional component, an alkali, and water and recovering molybdenum as an aqueous solution, or by roasting a mixture of a molybdenum-containing substance with an alkali and extracting the roasted mixture with water. Further, a molybdenum-containing precipitate can be obtained by the addition of an acid to the obtained solution. Additionally, catalysts containing molybdenum as the essential component can be prepared by using the obtained molybdenum -containing aqueous solution or precipitate.

Description

Specification

Molybdenum recovery method and catalyst production method

Technical field

The present invention relates to a method for recovering at least molybdenum from a molybdenum-containing material containing at least molybdenum, and a method for producing a catalyst using the recovered molybdenum.

Background art

[0002] Molybdenum-containing materials containing at least molybdenum are used, for example, in the production of (meth) acrolein and (meth) acrylic acid by vapor phase contact acid of propylene, isobutylene, or tert-butyl alcohol. Molybdenum bismuth iron-based complex oxide catalysts, molybdenum-vanadium complex oxide catalysts used in the production of acrylic acid using acrolein gas-phase contact acid, etc. are widely known.

[0003] Generally, in an industrial gas phase oxidation reaction, the catalyst is premised on the use for a certain period, and the catalyst after the use period is taken out from the reaction tube and replaced with a newly produced catalyst. At this time, the used spent catalyst contains many elements useful as catalyst production raw materials, such as molybdenum, bismuth, conoleto, nickel, vanadium, rubidium, cesium, and these elements, particularly the main components. Development of technology for recovering and reusing molybdenum has become a very important issue both economically and in reducing the burden on the environment

[0004] Regarding the reuse of spent catalyst, molybdenum bismuth-monoiron complex acid used in the production of (meth) acrolein and (meth) acrylic acid by propylene, isobutylene, or gas phase catalytic acid of tert-butyl alcohol. For metal catalysts, a regeneration method in which the spent catalyst used in the reaction is mixed with molybdenum oxide that is substantially inert to the reaction (see, for example, Patent Document 1), the spent catalyst used in the reaction, and unused in the reaction A method of using the composite oxide catalyst in the coexistence in the reaction (for example, see Patent Document 2) is known. In addition, in the case of molybdenum-vanadium-based composite oxide catalysts used in the production of acrylic acid by acrolein gas-phase contact acid, etc., a regeneration method in which a molybdenum-containing solution is added to the spent catalyst used in the reaction and calcined. (For example, refer to Patent Document 3), used catalyst 5 ~: LOO m There is known a regeneration method (for example, see Patent Document 4) in which the material is pulverized, reshaped, and fired.

[0005] In addition, with regard to the recovery and reuse of molybdenum and the like from spent catalysts, heteropolyacid catalysts used in the production of methacrylic acid by gas-phase catalytic acid of methacrolein, etc., the spent catalyst used in the reaction is used. Disperse in water and dissolve in Al force, then adjust the pH to recover a precipitate containing at least molybdenum and phosphorus and Z or arsenic. Recover the catalyst using the recovered precipitate. There are known methods for producing such catalysts (see, for example, Patent Documents 5 and 6).

Patent Document 1: Japanese Patent Laid-Open No. 07-165663

Patent Document 2: Japanese Patent Laid-Open No. 09-012489

Patent Document 3: Japanese Patent Laid-Open No. 2003-305367

Patent Document 4: Japanese Unexamined Patent Application Publication No. 2004-000936

Patent Document 5: Japanese Patent Laid-Open No. 2001-029799

Patent Document 6: International Publication No. 2005Z79983 Pamphlet

Disclosure of the invention

Problems to be solved by the invention

However, in the catalyst regeneration methods disclosed in Patent Documents 1 to 4 and the like, the catalyst is regenerated up to a certain level of activity, but the regenerated catalyst is used for gas phase contact. When the oxidation reaction is performed, there is a problem that the yield of the target product is lower than when a catalyst produced by a normal method is used.

[0007] Further, the methods for recovering molybdenum and the like disclosed in Patent Documents 5 and 6 are methods for recovering a precipitate containing at least molybdenum and phosphorus, which is a heteropolyacid-based catalytic force. In addition to containing bismuth or vanadium, its molybdenum-containing properties are known to recover molybdenum.

[0008] Therefore, an object of the present invention is a method for recovering molybdenum in a state in which it can be used as a raw material for catalyst production from a molybdenum-containing material containing at least molybdenum, in particular, a recovered used molybdenum-containing material. The present invention provides a method for producing a catalyst using molybdenum. Means for solving the problem

[0009] The inventors of the present invention diligently studied to solve the above problems, and disperse a molybdenum-containing material containing at least molybdenum and containing bismuth or vanadium in water, dissolving it in an alkali, and separating it. The present inventors have found a method for recovering molybdenum in a state where it can be used for the production of various catalysts containing molybdenum. In addition, a method for recovering molybdenum in a state where it can be used for the production of various catalysts containing molybdenum is also found by extracting with water water the roasted product obtained by adding alkali to at least molybdenum-containing material containing molybdenum. The present invention has been reached.

That is, the present invention has a step of obtaining a molybdenum-containing aqueous solution in which at least molybdenum is dissolved in water using a molybdenum-containing material containing at least molybdenum and containing bismuth or vanadium, an alkali, and water. This is a method for recovering molybdenum.

[0011] The present invention also includes (d) a step of mixing a molybdenum-containing material containing at least molybdenum and an alkali, (e) a step of roasting the obtained mixture at 600 to 1000 ° C, and f) extracting molybdenum contained in the obtained baked product with water to obtain a molybdenum-containing aqueous solution in which at least molybdenum is dissolved in water.

[0012] Further, the present invention includes (X) a step of adding an acid to the molybdenum-containing aqueous solution to adjust the pH of the molybdenum-containing aqueous solution to 3 or less to produce a molybdenum-containing precipitate, and (y) And the step of separating the molybdenum-containing precipitate.

[0013] Furthermore, the present invention is a method for producing a catalyst, characterized in that a catalyst containing at least molybdenum is produced using the molybdenum-containing aqueous solution or the molybdenum-containing precipitate obtained by the above method.

The invention's effect

[0014] According to the present invention, molybdenum can be recovered from a molybdenum-containing material containing at least molybdenum, in particular, a recovered used molybdenum-containing material in a state where it can be used as a raw material for catalyst production. Also, using the recovered molybdenum, it has the same performance as a new catalyst. Can be produced.

BEST MODE FOR CARRYING OUT THE INVENTION

[0015] The present invention is a method for recovering molybdenum from a molybdenum-containing material containing at least molybdenum, and is suitable for recovering molybdenum from molybdenum-containing material containing at least molybdenum and containing bismuth or vanadium. Examples of the molybdenum-containing material include a catalyst used in the production reaction of (meth) acrolein and Z or (meth) acrylic acid by vapor phase catalytic oxidation of propylene, isobutylene, and tert-butyl alcohol, acrolein, and the like. Examples include catalysts used in the production reaction of acrylic acid by gas phase catalytic oxidation.

[0016] In the case of a catalyst for the production of (meth) acrolein and Z or (meth) acrylic acid by propylene, isobutylene and tert-butyl alcohol! /, Any gas phase catalytic acid, the following formula (1) The composition is preferred! /.

[0017] Mo Bi Fe M ¹ X ¹ Y ¹ Ζ ¹ Si Ο (1)

a b c d e f g h i

(In the formula, Mo, Bi, Fe, Si, and O represent molybdenum, bismuth, iron, silicon, and oxygen, respectively, and M ¹ is at least one element selected from the group consisting of conoleto and nickel power. X ¹ represents at least one element selected from the group consisting of chromium, lead, manganese, calcium, magnesium, niobium, silver, barium, tin, tantalum, and zinc carbonate, and Y ¹ represents phosphorus. Represents at least one element selected from the group consisting of boron, sulfur, selenium, tellurium, cerium, tungsten, antimony and titanium, and Z ¹ is selected from the group consisting of lithium, sodium, potassium, rubidium, cesium and thallium. Indicates at least one selected element: a, b, c, d, e, f, g, h, and i represent the atomic ratio of each element, and when a = 12, b = 0.01-3 , C = 0.01-5, d = l-12, e = 0 to 8, f = 0 to 5, g = 0.001 to 2, h = 0 to 20, and i is an oxygen atomic ratio necessary to satisfy the valence of each component.)

In the case of a catalyst for producing acrylic acid by vapor phase catalytic oxidation of acrolein, a catalyst having the composition of the following formula (2) is preferable.

[0018] Mo VA ² X ² Y ² Ο (2)

j k 1 m η ο

(Where Μο, V and Ο represent molybdenum, vanadium and oxygen, respectively, and Α ² is at least selected from the group consisting of iron, cobalt, chromium, aluminum and strontium force. Indicates a kind of element, X ² is germanium, boron, arsenic, selenium, silver, kaen, sodium

Y ² represents magnesium, titanium, manganese, copper, zinc, zirconium, niobium, and at least one element selected from the group consisting of tellurium, lithium, antimony, phosphorus, potassium, and barium And at least one element selected from the group consisting of tungsten, tantalum, calcium, tin and bismuth. j, k, 1, m, n and o represent the atomic ratio of each element.When j = 12, k = 0.01-6, 1 = 0-5, m = 0-10, n = 0- 5 and o is the number of oxygen atoms necessary to satisfy the valence of each component. )

In addition, as the molybdenum-containing material for recovering molybdenum, those usually used in the production reaction of (meth) acrolein and Z or (meth) acrylic acid, the production reaction of acrylic acid, etc. are used. It is not particularly limited to use a material that is no longer used, or one that has been withdrawn from the reaction tube during use.

In the present invention, molybdenum is recovered from the molybdenum-containing material by a method including a step of obtaining an aqueous solution containing at least molybdenum using a molybdenum-containing material, an alkali, and water. That is, in order to recover molybdenum from the molybdenum-containing material, a molybdenum-containing aqueous solution is obtained by bringing the molybdenum-containing material into contact with an alkali so as to be dissolved in water.

[0020] Molybdenum-containing physical strength containing at least molybdenum In the first embodiment for recovering molybdenum, first, a dispersion is prepared in which a molybdenum-containing material containing at least molybdenum and containing bismuth or vanadium is dispersed in water ( Step (a)). Then, an alkali is added to the dispersion to adjust the pH of the dispersion to 8 or more (step (b)). By adjusting the pH, at least a part of molybdenum in the molybdenum-containing material is dissolved in water.

[0021] The alkali that can be used here is not particularly limited, and examples thereof include sodium hydroxide, potassium hydroxide, potassium hydroxide, sodium carbonate, aqueous ammonia, and the like. Sodium is preferred. When all or part of the molybdenum-containing material is in a reduced state, air calcination, chlorination, hydrogen peroxide treatment, etc. before adding alkali, or chlorination, hydrogen peroxide treatment, etc. after adding alkali It is preferable to oxidize with. The amount of alkali added is preferably such that the pH becomes 8.5 to 13 which is the amount that makes the pH of the dispersion 8 or higher. [0022] Further, after pH adjustment, it is preferable to hold for a certain period of time in order to dissolve molybdenum. The holding time at this time is preferably about 0.5 to 24 hours, and the temperature of the liquid is preferably from room temperature to about 90 ° C. Although it may be left still during the holding, it is preferable to stir.

[0023] Dispersion force insoluble matter whose pH is adjusted to 8 or more as described above is removed, and a molybdenum-containing aqueous solution in which molybdenum is dissolved in water can be obtained as a filtrate (step (c)). The method for removing the insoluble matter is not particularly limited, and for example, general methods such as filtration separation such as gravity filtration, pressure filtration, vacuum filtration, filter press, and centrifugal separation can be applied.

[0024] Molybdenum-containing physical force containing at least molybdenum In the second embodiment for recovering molybdenum, first, a molybdenum-containing material containing at least molybdenum and an alkali are mixed (step (d)), and the resulting mixture is mixed. Roast at 600-1000 ° C (step (e)). Then, molybdenum contained in the obtained roasted product is extracted with water (step (f)). By doing so, at least a part of molybdenum contained in the roasted product is dissolved and extracted in water, and a molybdenum-containing aqueous solution in which molybdenum is dissolved in water can be obtained as an extract. In this embodiment, the present invention can also be applied when the molybdenum-containing material does not contain bismuth or vanadium, but is suitable when the molybdenum-containing material contains bismuth or vanadium.

[0025] The alkali that can be used here is not particularly limited, and examples thereof include sodium hydroxide, sodium carbonate, sodium bicarbonate, and the like, and sodium carbonate and sodium hydroxide are particularly preferable. The amount of alkali added is preferably 1 or more times the equivalent of molybdenum, tandastene and vanadium contained in the molybdenum-containing material. Although there is no problem even if the amount of alkali added is large, it is contained in the molybdenum-containing material because the amount of the cleaning liquid used to remove sodium element can be reduced by washing the recovered molybdenum-containing precipitate described later. Less than twice the equivalent of molybdenum, tungsten and vanadium elements is preferred.

[0026] The roasting conditions are 600 to 1000 ° C in an oxygen-containing gas atmosphere such as air. If the roasting temperature is less than 600 ° C, molybdenum extraction is insufficient and the recovery rate is low. When the roasting temperature exceeds 1000 ° C, the recovery rate decreases due to the scattering of molybdenum. The roasting time is preferably 0.5 hours or more.

[0027] The molybdenum-containing aqueous solution obtained by the above method can be used as a molybdenum raw material. This is a form of molybdenum recovery that can be used for the production of a catalyst. However, it is preferable to adjust the pH to recover molybdenum as a molybdenum-containing precipitate containing at least molybdenum. Specifically, an acid is added to the obtained molybdenum-containing aqueous solution to adjust the pH of the molybdenum-containing aqueous solution to 3 or less, thereby producing a molybdenum-containing precipitate containing at least a part of molybdenum (step (X)). It is preferable to recover the molybdenum as a molybdenum-containing precipitate by separating the molybdenum-containing precipitate (step (y)).

[0028] The acid that can be used here is not particularly limited, and examples thereof include strong acids such as hydrochloric acid, nitric acid, and sulfuric acid, and nitric acid or hydrochloric acid is preferable. The amount of acid added is preferably such that the pH of the molybdenum-containing aqueous solution is 3 or less, particularly preferably 2 or less.

[0029] After pH adjustment, it is preferable to hold for a certain period of time for precipitation. The holding time at this time is preferably about 0.5 to 24 hours, and the temperature of the liquid is preferably from room temperature to about 90 ° C. Although it may be left still during the holding, it is preferable to stir.

[0030] A method for separating the molybdenum-containing precipitate is not particularly limited, and general methods such as gravity filtration, pressure filtration, vacuum filtration, filtration separation such as a filter press, and centrifugal separation can be used. The separated molybdenum-containing precipitate may be washed as necessary to remove impurities. In this case, the washing liquid may be selected in consideration of the use and solubility of the molybdenum-containing precipitate. For example, pure water, a thin aqueous solution of ammonium nitrate, salt and ammonium, etc. may be used. It is preferable that the molybdenum-containing precipitate after the washing is not more than 0.1 mol with respect to 12 mol of sodium element and chlorine power molybdenum element contained in the molybdenum-containing precipitate. Therefore, the cleaning conditions are set.

[0031] When the molybdenum-containing material used for the recovery contains silicon, it is preferable to adjust the pH of the molybdenum-containing aqueous solution to 4 to 8 to precipitate and remove it.

[0032] Further, phosphorus may be contained in the molybdenum-containing material used for recovery. Depending on the composition or preparation method of the catalyst produced using the recovered molybdenum-containing aqueous solution or molybdenum-containing precipitate, it is preferable to remove part or all of phosphorus. As a method of removing phosphorus, the pH of the molybdenum-containing aqueous solution is adjusted to 6 to 12, preferably 7 to L 1. Then, it is preferable to add a solution containing magnesium element and ammonia water to form a precipitate containing at least magnesium and phosphorus, and to separate and remove the precipitate. Here, it is preferable that the amount of magnesium element and ammonia to be added is 1 mol or more per 1 mol of phosphorus element. The compound having a magnesium element to be used is not particularly limited, and magnesium chloride, magnesium sulfate, magnesium nitrate and the like can be used.

[0033] In the molybdenum vanadium-based complex oxide catalyst used for the production of acrylic acid, vanadium is contained in the molybdenum-containing aqueous solution. Depending on the composition or preparation method of the catalyst produced using the recovered molybdenum-containing aqueous solution or molybdenum-containing precipitate, it is preferable to remove part or all of vanadium. The method for removing vanadium is not particularly limited. For example, after adjusting the pH of a molybdenum-containing aqueous solution containing vanadium in addition to molybdenum to 3.5 to 7.5, it is adsorbed and removed with a weakly basic anion exchange resin. Examples of the method include a method of precipitation separation using ammonium sulfate.

[0034] In the present invention, the molybdenum-containing aqueous solution and the recovered molybdenum-containing precipitate obtained in this manner (hereinafter collectively referred to as "recovered molybdenum-containing material") are used as the catalyst production raw material. it can. The state of the recovered molybdenum-containing material used in the catalyst production is not particularly limited, and may be in a solution state, a wet state, or a dry state. In addition, when it is desired to use the catalyst in the form of an oxide, it is possible to use these recovered molybdenum-containing materials, particularly those obtained by calcining the recovered molybdenum-containing precipitates. (Hereinafter, this fired product is also a form of “recovered molybdenum-containing material”). The firing conditions are preferably 300 to 600 ° C in an oxygen-containing gas atmosphere such as air, and the firing time is preferably 0.5 hours or more.

[0035] In the present invention, the method for producing a catalyst using the recovered molybdenum-containing material is not particularly limited, and it is used as a raw material from various methods such as a coprecipitation method, an evaporation to dryness method, and an oxide mixing method. It is suitably selected according to the state of the recovered molybdenum-containing material.

[0036] The molybdenum raw material used for the production of the catalyst may be only the recovered molybdenum-containing material. If necessary, the molybdenum raw material or molybdenum recovered by a method other than the above-described recovery method may be used. Ore isotope It can be used together with other molybdenum raw materials such as molybdenum raw materials used in the production of ordinary catalysts. Examples of the molybdenum raw material used for normal catalyst production include molybdenum molybdenum salts, oxides, halides, oxygen acids, and the like. Specific examples thereof include ammonium molybdate and triacids. And molybdenum, molybdic acid, and salt molybdenum. The production method of the molybdenum raw material used for normal catalyst production is not particularly limited. For example, crude molybdenum trioxide obtained by roasting molybdenum ore is washed with nitric acid, dissolved in ammonia water, purified, Next, the molybdic acid obtained by adjusting the pH with nitric acid was dissolved again in aqueous ammonia, and then concentrated and crystallized to obtain paramolybdic acid ammonium and paramolybdic acid ammonium-molybdbudene acid. For example, molybdenum trioxide obtained by firing sinter.

[0037] In addition, raw materials other than the molybdenum raw material used for the production of the catalyst are not particularly limited, and a combination of nitrate, carbonate, acetate, ammonium salt, oxide, halide, oxygen acid, etc. of each element. Can be used. For example, bismuth, bismuth nitrate, bismuth, bismuth chloride, etc .; vanadium, ammonium metavanadate, vanadium pentoxide, etc .; phosphorous, phosphoric acid, phosphorus pentoxide, etc. Ammonium phosphate can be used.

[0038] Specific catalyst production methods include, for example, production of (meth) acrolein and Z or (meth) acrylic acid by any gas phase catalytic oxidation of propylene, isobutylene, and tert-butyl alcohol. In the case of producing a molybdenum bismuth iron-based composite oxide catalyst, for example, there may be mentioned a method of firing a slurry containing at least bismuth and an iron element together with a molybdenum raw material containing a recovered molybdenum-containing material. The molybdenum-vanadium complex oxide catalyst used in the production of acrylic acid by vapor phase catalytic oxidation of acrolein is calcined by drying a slurry containing at least the vanadium element together with the molybdenum raw material containing the recovered molybdenum-containing material. And the like. Examples of the heteropolyacid catalyst used in the production of methacrylic acid by vapor phase contact acid of methacrolein include a method of firing a dry slurry containing at least phosphorus together with a molybdenum raw material containing a recovered molybdenum-containing material. .

[0039] Further, in the production of the catalyst, the catalyst structure contained in the recovered molybdenum-containing material used as a raw material. In consideration of the content of impurities derived from the elements, the amount of counter ions contained in the raw material may be added when the amount of the raw material containing these elements is adjusted. For example, when the amount of vanadium element is adjusted by reducing the amount of ammonium metavanadate, the amount of potassium ions is reduced by adding ammonia water to the lack of ammonium ions. When the amount of potassium nitrate is adjusted by reducing the amount of potassium nitrate or cesium nitrate added, the insufficient nitrate ions can be adjusted by adding nitric acid or the like.

[0040] In the production of the catalyst of the present invention, the liquid temperature of the solution or slurry may be the same as in the case of normal catalyst production that does not use the recovered molybdenum-containing material of the present invention. It may be different from the usual catalyst production in part or all. The liquid temperature is preferably appropriately determined from the particle size distribution of the precipitated particles in the slurry, the moldability of the obtained powder, the pore distribution of the catalyst, the reaction results of the catalyst, and the like.

In the present invention, the method for drying the slurry is not particularly limited, and a drying method using a box-type dryer, a spray dryer, a drum dryer, a slurry dryer, or the like can be used. The dried product (catalyst precursor) obtained at this time is preferably in the form of a powder in consideration of molding. The dried product may be molded as it is, or may be molded after firing. For example, molybdenum bismuth monoiron complex oxide used in the production of (meth) acrolein and Z or (meth) acrylic acid. For the catalyst, it is preferable that the dried product is calcined in the range of 200 to 400 ° C. for about 1 to 5 hours, shaped as necessary or supported on an inert carrier, and then calcined.

[0042] Since the firing conditions vary depending on the raw material of the catalyst used, the catalyst composition, and the preparation conditions, for example, in the case of a molybdenum bismuth-iron-based complex oxide catalyst, an oxygen-containing gas such as air is used. Firing is carried out under conditions of 400 to 650 ° C, preferably 450 to 600 ° C for 0.5 hour or more, preferably 1 to 40 hours under circulation and under Z or inert gas. In the case of a molybdenum-vanadium-based composite oxide catalyst, similarly, under an oxygen-containing gas flow such as air and Z or inert gas flow, 250 to 500 ° C, preferably 300 to 450 ° C, 0.5 hours or more, preferably Bake for 1 to 40 hours. Further, in the case of a heteropolyacid catalyst, it is also 300 to 500 ° C, preferably 300 to 450 ° C under an oxygen-containing gas flow such as air and Z or inert gas flow, preferably at 300 to 450 ° C for 0.5 hour or more. Baking is preferably performed for 1 to 40 hours. [0043] In the present invention, the molding method is not particularly limited, and examples thereof include tableting molding, extrusion molding, granulation, and support. Examples of the supported catalyst carrier include inert carriers such as silica, alumina, silica′alumina, silicon carbide and the like. In molding, for example, inorganic salts such as barium sulfate and ammonium nitrate, graphite, etc., for the purpose of controlling the specific surface area, pore volume and pore distribution of the molded product and increasing mechanical strength. Additives such as lubricants, celluloses, starches, polybutyl alcohol, stearic acid and other organic substances, silica sols, hydroxide sols such as alumina sols, inorganic fibers such as whiskers, glass fibers and carbon fibers Moyo.

[0044] The reaction conditions for carrying out the gas phase catalytic oxidation reaction using the catalyst produced by the method of the present invention are not particularly limited, and known reaction conditions can be applied. The following are the reaction conditions for producing (meth) acrolein or methacrolein by vapor phase catalytic oxidation of propylene, isobutylene, and tert butyl alcohol, and acrylic acid is produced by vapor phase catalytic oxidation of acrolein. The reaction conditions in this case and the reaction conditions in the case of producing methacrylic acid by the gas phase contact acid of methacrolein will be described.

[0045] Produce acrolein (in the case of propylene) or methacrolein (in the case of isobutylene or tert-butyl alcohol) from propylene, isobutylene, and tert-butyl alcohol! In this case, the concentration of the raw material in the raw material gas is preferably 1 to 20% by volume, and more preferably 3 to 10% by volume, which can be varied over a wide range. In addition, the raw material may contain a small amount of impurities that do not substantially affect the reaction. The raw material gas may contain such impurities.

[0046] Although the source gas needs to contain molecular oxygen, the amount of molecular oxygen in the source gas is preferably 0.4 to 4 times the molar amount of the raw material, particularly 0.5 to 3 times. Mole is preferred. Although it is industrially advantageous to use air as the molecular oxygen source of the raw material gas, air enriched with pure oxygen and oxygen can be used if necessary. The raw material gas is preferably diluted with an inert gas such as nitrogen or carbon dioxide, water vapor or the like.

[0047] The reaction pressure of the gas phase catalytic oxidation is from atmospheric pressure to several atmospheres. The reaction temperature is usually 200-450. C, preferably 250-400 ° C. The contact time between the raw material gas and the catalyst is usually 1.5 to 15 seconds, preferably 2 to 7 seconds. [0048] A catalyst for producing acrolein or methacrolein by any gas phase catalytic oxidation of propylene, isobutylene, and tert-butyl alcohol has a composition represented by the following formula (1): Is preferred.

[0049] Mo Bi Fe M ¹ X ¹ Y ¹ Z ¹ Si O (1)

a b c d e f g h i

When acrylic acid is produced by acrolein gas-phase contact acid, the concentration of acrolein in the raw material gas can be varied over a wide range, preferably 1-20% by volume, especially 3-10% by volume. . The raw material acrolein may contain a small amount of impurities such as water and lower saturated aldehyde that do not substantially affect the reaction. The raw material gas contains such acrolein-derived impurities. Anyway.

[0050] The source gas must contain molecular oxygen, but the amount of molecular oxygen in the source gas is preferably 0.4 to 4 times the mol of acrolein, particularly 0.5 to 3 times. Mole is preferred. It is industrially advantageous to use air as the molecular oxygen source of the source gas, but air enriched with pure oxygen and oxygen can also be used if necessary. The raw material gas is preferably diluted with an inert gas such as nitrogen or carbon dioxide, water vapor or the like.

[0051] The reaction pressure of gas phase catalytic oxidation is from atmospheric pressure to several atmospheres. The reaction temperature is usually 200-450. C, preferably 250-400 ° C. The contact time between the raw material gas and the catalyst is usually 1.5 to 15 seconds, preferably 2 to 7 seconds.

[0052] A catalyst for producing acrylic acid by vapor phase contact acid of acrolein is represented by the following formula (2) U, which has a composition represented by U, is preferred.

[0053] Mo VA ² X ² Y ² Ο (2)

j k 1 m η ο

(In the formula, Μο, V and Ο represent molybdenum, vanadium and oxygen, respectively, and Α ² represents at least one element selected from the group consisting of iron, cobalt, chromium, aluminum and strontium, and X ² shows germanium, boron, arsenic, selenium, silver, Keimoto, sodium, tellurium, lithium, antimony, phosphorus, at least one element selected from potassium and Bariumuka Ra group consisting, Upsilon ^2, It represents at least one element selected from the group consisting of magnesium, titanium, manganese, copper, zinc, zirconium, niobium, tungsten, tantalum, calcium, tin and bismuth j, k, 1, m , N and o represent the atomic ratio of each element, and when j = 12, k = 0.01-6, 1 = 0-5, m = 0-10, n = 0-5, o is the above Necessary to satisfy the valence of each component The number of oxygen atoms.

Further, when producing methacrylic acid by gas phase contact acid of methacrolein, the concentration of methacrolein in the raw material gas is preferably 1 to 20% by volume which can be changed over a wide range.

In particular, 3 to 10% by volume is preferable. The raw material methacrolein may contain a small amount of impurities that do not substantially affect the reaction, such as water and lower saturated aldehydes. However, the raw material gas contains such impurities derived from methacrolein. It may be.

[0054] Although the source gas needs to contain molecular oxygen, the amount of molecular oxygen in the source gas is 0.4 to 4 times the molar force of methacrolein, particularly 0.5 to A 3-fold mole is preferred. Although it is industrially advantageous to use air as the molecular oxygen source of the source gas, air enriched with pure oxygen can be used if necessary. The source gas is preferably diluted with an inert gas such as nitrogen or carbon dioxide, or water vapor.

[0055] The reaction pressure of the gas phase catalytic oxidation is from atmospheric pressure to several atmospheres. The reaction temperature is usually 200-450. C, preferably 250-400 ° C. The contact time between the raw material gas and the catalyst is usually 1.5 to 15 seconds, preferably 2 to 7 seconds.

[0056] The catalyst for producing methacrylic acid by gas-phase catalytic oxidation of methacrolein is preferably one having a composition represented by the following formula (3).

[0057] Mo PX ³ Y ³ O (3)

P q r s t

(Where Mo, P and O represent molybdenum, phosphorus and oxygen, respectively, X ³ is potassium , Rubidium, represents at least one element selected from the group also cesium and thallium force, Y ³ iron, the Leto, nickel, copper, zinc, magnesium, calcium, strontium arm, Bruno potassium, titanium, vanadium, chromium , Tungsten, Manganese, Silver, Boron, Ca, Aluminum, Gallium, Germanium, Tin, Lead, Arsenic, Antimony, Bismuth, Niobium, Tantalum, Zirconium, Indium, Zio, Selenium, Tellurium, Lanthanum and Cerium Represents at least one element. p, q, r, s and t represent the atomic ratio of each element, and when ρ = 12, q = 0.1 to 3, r = 0.01 to 3, s = 0 to 3, and t Is the atomic ratio of oxygen necessary to satisfy the atomic ratio of each component. )

Example

[0058] Hereinafter, the present invention will be described by way of examples. In the examples, “parts” is parts by mass, and quantitative analysis of contained elements (or molecules) was performed by ICP emission spectrometry and atomic absorption spectrometry. Analysis of raw materials and products in the production of acrolein, methacrolein, acrylic acid, or methacrylic acid was performed by gas chromatography. The recovery rate of molybdenum, the conversion rate of propylene, isobutylene, acrolein, or methacrolein as raw materials, and the selectivity and yield of the produced acrolein, methacrolein, acrylic acid, or methacrylic acid are as follows. Defined in

[0059] a) Molybdenum recovery

Recovery rate (mass%) = (W / W) X 100

Here, W is the mass of recovered molybdenum, and W is the mass of molybdenum contained in the catalyst used for recovery.

[0060] b) Conversion rate of raw material propylene, isobutylene, acrolein, or methacrolein, selectivity and yield of acrolein, methacrolein, acrylic acid, or methacrylic acid produced

Conversion (mol%) = (B / A) X 100

Selectivity (mol%) = (C / B) X 100

Yield (mol%) = (CZA) X 100

Where A is the number of moles of propylene, isobutylene, acrolein, or methacrolein supplied, and B is the number of reacted propylene, isobutylene, acrolein, or methacrolein. C is the number of moles of acrolein, methacrolein, acrylic acid or methacrylic acid produced.

[0061] [Reference Example 1]

(Manufacture of acrolein production catalyst A)

In 1000 parts of pure water, 500 parts of ammonium paramolybdate, 6.2 parts of ammonium tungstate, 1.4 parts of potassium nitrate, 27.5 parts of antimony trioxide, and bismuth trioxide 66. 0 parts were added and stirred with heating (Liquid A). Separately, 114.4 parts of iron nitrate, 295.3 parts of cobalt nitrate, and 35.1 parts of zinc nitrate were sequentially dissolved in 1000 parts of pure water (solution B). After the liquid B was made into an aqueous slurry of the liquid A, the aqueous slurry was dried with a spray dryer (dryer inlet temperature: 300 ° C.). The dried powder thus obtained was calcined at 300 ° C for 1 hour, then formed into a 3mm diameter cylinder with a diameter and height of 3mm, and calcined at 510 ° C for 3 hours. A (Composition excluding oxygen atoms: Mo Bi Fe Co Zn W

12 1. 2 1. 2 4. 3 0. 5 0. 1

Sb K;) was obtained.

0. 8 0. 06

[0062] (Acrolein production test A)

The catalyst A for acrolein production is packed in a reaction tube, and a mixed gas of 5% by volume of propylene, 12% by volume of oxygen, 10% by volume of steam, and 73% by volume of nitrogen is reacted at 310 ° C and contact time is 3.6. In seconds, propylene conversion 98.4%, acrolein selectivity 90.1%, acrylic acid selectivity 5.9%, acrolein yield 88.7%, acrylic acid yield 5. It was 8%.

[Example 1]

(Molybdenum recovery A1)

The catalyst after the production of acrolein of Reference Example 1 for 2000 hours was recovered. 100 parts of this recovered catalyst contained 43.9 parts of molybdenum, 0.7 part of tungsten, 9.6 parts of bismuth, 2.6 parts of iron, 3.7 parts of antimony, 9.7 parts of corundol, and 1.3 parts of zinc. Part and potassium 0.1 part. The composition of elements excluding oxygen atoms is Mo Bi Fe Co Zn W Sb K

12 1. 2 1. 2 4. 3 0. 5 0. 1 0. 8 0. 600 parts of the recovered catalyst was dispersed in 2400 parts of pure water. 45% by mass

. 06

After adding 800 parts of sodium hydroxide aqueous solution and stirring at 60 ° C. for 3 hours (ρΗ was 12.6 at this time), the insoluble part was filtered off to obtain a molybdenum-containing aqueous solution. Obtained in this way 36% by mass hydrochloric acid was added to the obtained molybdenum-containing aqueous solution to adjust the pH to 1.0, and the mixture was stirred and maintained at 30 ° C for 3 hours with stirring. The precipitate thus formed was filtered and washed with a 2% by mass aqueous ammonium nitrate solution to obtain a molybdenum-containing precipitate (recovered molybdenum-containing material A1). The recovered molybdenum-containing material A1 contained 257.4 parts of molybdenum, 3.6 parts of tungsten and 0.1 part of potassium. The recovery rate of molybdenum at this time is 97.8%.

[0064] (Manufacture of acrolein production catalyst A1)

After dispersing the whole amount of the recovered molybdenum-containing material A1 obtained above in pure water 950 parts, it was heated and stirred example mosquitoes卩135 parts 29 mass ^_0/0 aqueous ammonia. To this was added 0.8 parts of ammonium paratungstate, 1.1 parts of potassium nitrate, 26.1 parts of antimony trioxide and 62.5 parts of bismuth trioxide, and the mixture was further heated and stirred (Liquid A). . Separately, 108.4 parts of iron nitrate, 279.8 parts of nitrate nitrate, and 33.3 parts of zinc nitrate were sequentially dissolved in 950 parts of pure water (solution B). After B liquid is added to A liquid to make an aqueous slurry, drying, calcination, molding, and calcination are performed in the same manner as in the manufacture of acrolein production catalyst A of Reference Example 1 to obtain acrolein production catalyst A 1. It was. The composition of this acrolein production catalyst A1 excluding oxygen atoms is the same as that of the acrolein production catalyst A produced in Reference Example 1. Mo Bi Fe Co Zn W Sb K

12 1. 2 1. 2 4. 3 0. 5 0. 1 0. 8

0. 06

[0065] (Acrolein production test Al)

Using this acrolein production catalyst A1, acrolein was produced under the same reaction conditions as in acrolein production test A of Reference Example 1. As a result, the propylene conversion rate was 98.3% and acrolein selectivity was 90.2%. The selectivity for acrylic acid was 5.8%, the yield of acrolein was 88.7%, and the yield of acrylic acid was 5.7%. .

[Comparative Example 1]

(Molybdenum recovery A2)

Recovery of Molybdenum in Example 1 In A1, the amount of 45% by weight aqueous sodium hydroxide and sodium hydroxide was changed to 200 parts (pH after addition was 7.1). In the same manner as in recovery A1, “recovered molybdenum-containing material A2” was obtained. Contains recovered molybdenum Product A2 contained 110.9 parts molybdenum, 3.0 parts tungsten, and 0.18 parts potassium. At this time, the recovery rate of molybdenum was 42.1%, which greatly reduced the recovery rate of molybdenum.

[0067] [Reference Example 2]

(Manufacture of catalyst acrolein B)

To 1000 parts of pure water, 500 parts of ammonium paramolybdate, 6.2 parts of ammonium tungstate, and 1.4 parts of potassium nitrate were added and dissolved at 60 ° C (solution A). Separately, 41.9 parts of 60 mass% nitric acid aqueous solution was added to 1000 parts of pure water, and after homogenizing, 103.0 parts of bismuth nitrate was dissolved. To this, 133.5 parts of iron nitrate, 295.3 parts of corn nitrate, and 14.0 parts of zinc nitrate were sequentially added and dissolved (solution B). Liquid B was added to liquid A to obtain an aqueous slurry, and then 6.9 parts of antimony trioxide was aged at 80 ° C. for 1 hour, and then evaporated to dryness. The cake-like material thus obtained was dried at 120 ° C, calcined at 300 ° C for 1 hour, and then pulverized. After that, it was pressure-molded into a cylindrical shape with a diameter and height of 3 mm, and calcined at 500 ° C for 6 hours.

12 0. 9 1. 4 4

Zn W Sb K) was obtained.

.3 0. 2 0. 1 0. 2 0. 06

[0068] (Acrolein production test B)

As a result of producing acrolein using this acrolein production catalyst B under the same reaction conditions as in acrolein production test A of Reference Example 1, the propylene conversion was 99.5% and the acrolein selectivity was 91.0. %, The selectivity of acrylic acid was 6.6%, the yield of acrolein was 90.5%, and the yield of acrylic acid was 6.6%.

[Example 2]

(Molybdenum recovery B1)

The catalyst after the production of acrolein of Reference Example 2 for 2000 hours was recovered. 100 parts of this recovered catalyst contained 47.1 parts molybdenum, 0.8 parts tungsten, 7.7 parts bismuth, 3.2 parts iron, 1.0 part antimony, 10.4 parts connort, 0.5 parts zinc. Part, and 0.1 part potassium. The composition of elements excluding oxygen atoms is Mo Bi Fe Co Zn W Sb

12 0. 9 1. 4 4. 3 0. 2 0. 1 0. 2

K. 600 parts of this recovered catalyst is mixed with 350 parts of sodium carbonate,

0. 06

It was inserted into a tally kiln and baked at a baking temperature of 800 ° C for 1 hour to obtain a baked product. Then obtained The roasted product was mixed with pure water and stirred at 60 ° C. for 3 hours, and then the insoluble part was filtered off to obtain a molybdenine-containing aqueous solution. From the molybdenum-containing aqueous solution thus obtained, a molybdenum-containing precipitate (recovered molybdenum-containing material B1) was obtained in the same manner as molybdenum recovery A1 in Example 1. The recovered molybdenum-containing material B1 contained 274.8 parts molybdenum, 4.2 parts tungsten, and 0.1 parts potassium. The molybdenum recovery rate at this time was 97.3%.

[0070] (Production of acrolein production catalyst B1)

After dispersing the whole amount of the recovered molybdenum-containing compound B 1 obtained above in pure water 1000 parts, heated and stirred example mosquitoes卩29 mass ^_0/0 aqueous ammonia 144 parts. To this, 0.3 part of ammonium paratungstate and 1.2 parts of potassium nitrate were added and dissolved at 60 ° C. (solution A). Separately, 42.4 parts of a 60% by weight nitric acid aqueous solution was added to 1000 parts of pure water, and after homogenizing, 104.2 parts of bismuth nitrate was dissolved. To this, 135.0 parts of iron nitrate, 298.7 parts of cobalt nitrate, and 14.2 parts of zinc nitrate were sequentially added and dissolved (solution B). Liquid B was added to liquid A to prepare an aqueous slurry, 7.0 parts of antimony trioxide was added, and the mixture was aged at 80 ° C. for 1 hour, and then evaporated to dryness. The cake-like material thus obtained was dried at 120 ° C, calcined at 300 ° C for 1 hour, and then pulverized. Thereafter, it was pressure-molded into a cylindrical shape having a diameter and height of 3 mm, and calcined at 500 ° C. for 6 hours to obtain acrolein production catalyst B 1. The composition of this acrolein production catalyst B 1 excluding oxygen atoms is the same as that of the acrolein production catalyst B produced in Reference Example 2.

BiFeCoZnWSbK.

12 0. 9 1. 4 4. 3 0. 2 0. 1 0. 2 0. 06

[0071] (Acrolein production test Bl)

Using this acrolein production catalyst B1, acrolein was produced under the same reaction conditions as in acrolein production test A of Reference Example 1. As a result, the propylene conversion was 99.6% and the acrolein selectivity was 90.8%. The selectivity for acrylic acid was 6.8%, the yield of acrolein was 90.4%, and the yield of acrylic acid was 6.8%. .

[Comparative Example 2]

(Molybdenum recovery B2)

Recovery of molybdenum in Example 2 In B1, except that the roasting temperature was changed to 1200 ° C Recovery of molybdenum in Example 2 “Recovered molybdenum-containing material B2” was obtained in the same manner as in the recovery Bl. The recovered molybdenum-containing material B2 contained 178.9 parts of molybdenum, 4.2 parts of tungsten, and 0.06 parts of potassium. At this time, the recovery rate of molybdenum was 63.3%, and the recovery rate was greatly reduced.

[Comparative Example 3]

(Molybdenum recovery B3)

In the molybdenum recovery B1 of Example 2, “recovered molybdenum-containing material B3” was obtained in the same manner as the molybdenum recovery B1 of Example 2, except that the roasting temperature was changed to 400 ° C. The recovered molybdenum-containing material B3 contained 115.9 parts molybdenum, 2.4 parts tungsten, and 0.18 parts potassium. At this time, the recovery rate of molybdenum was 41.0%, and the recovery rate dropped significantly.

[0074] [Reference Example 3]

(Production of methacrolein production catalyst C)

In 500 parts of pure water, 500 parts of ammonium paramolybdate, 6.2 parts of ammonium tungstate, and 27.6 parts of cesium nitrate were added and dissolved at 60 ° C (solution A). ). Separately, 49.9 parts of a 60% by weight nitric acid aqueous solution was added to 1000 parts of pure water, and after homogenizing, 80.1 parts of bismuth nitrate was dissolved. To this, 200.2 parts of iron nitrate, 295.3 parts of Konol nitrate, 85.8 parts of nickel nitrate, and 14.0 parts of zinc nitrate were sequentially added and dissolved (solution B). Liquid B was added to the liquid A to form an aqueous slurry, and then 38.5 parts of antimony trimonate was aged at 80 ° C. for 1 hour, and then evaporated to dryness. The cake-like material thus obtained was dried at 120 ° C, calcined at 300 ° C for 1 hour, and then pulverized. After that, it was pressure-molded into a cylindrical shape with a diameter and height of 3 mm, and calcined at 500 ° C for 6 hours to produce catalyst C for methacrolein C (formation to remove oxygen atoms: Mo Bi Fe Ni Co Zn W Sb Cs).

12 0. 7 2. 1 2. 5 4. 9 0. 2 0. 1 0. 7 0. 6

[0075] (Production test C of methacrolein)

The catalyst C for producing methacrolein is charged into a reaction tube, and a mixed gas of 5% by volume of isobutylene, 12% by volume of oxygen, 10% by volume of water vapor, and 73% by volume of nitrogen is reacted at 340 ° C and contact time is 3.6 seconds. The conversion rate of isobutylene was 97.7%, the selectivity of methacrolein was 89.1%, the selectivity of methacrylic acid was 3.0%, the yield of methacrolein was 87.1%, Yield 2.9%.

[Example 3]

(Molybdenum recovery C1)

The catalyst after the production of methacrolein of Reference Example 3 for 2000 hours was recovered. 100 parts of this recovered catalyst contained 40.4 parts of molybdenum, 0.6 part of tungsten, 5.1 parts of bismuth, 4.1 parts of iron, 3.0 parts of antimony, 5.1 parts of nickel, and 10.1 parts of Conor. , 0.5 parts of zinc, and 2.8 parts of cesium. It should be noted that the elements of elements other than oxygen atoms are Mo Bi Fe

12 0. 7 2. 1

Ni Co Zn W Sb Cs. 600 parts of the recovered catalyst is converted to 2400 parts of pure water.

2. 5 4. 9 0. 2 0. 1 0. 7 0. 6

Dispersed. To this was added 800 parts of 45% by weight sodium hydroxide aqueous solution and stirred at 60 ° C for 3 hours (the pH was 12.8 at this time), and then the insoluble part was filtered off to obtain a molybdenum-containing aqueous solution. Obtained. From the molybdenum-containing aqueous solution thus obtained, a molybdenum-containing precipitate (recovered molybdenum-containing material C1) was obtained in the same manner as the molybdenum recovery A1 of Example 1. The recovered molybdenum content C1 contained 235.8 parts molybdenum, 3.0 parts tungsten, and 6.6 parts cesium. At this time, the recovery rate of molybdenum was 97.2%.

[0077] (Production of catalyst for production of methacrolein C1)

After dispersing the whole amount of the resulting recovered molybdenum-containing material C1 in the pure water 870 parts, it was heated and stirred with 29 mass ^_0/0 aqueous ammonia 123.5 parts. To this, 1.1 parts of ammonium paratungstate and 14.3 parts of cesium nitrate were added and dissolved at 60 ° C (solution A). Separately, 36.4 parts of 60% by weight nitric acid aqueous solution was added to 870 parts of pure water, and after homogenizing, 69.5 parts of bismuth nitrate was dissolved. In this solution, 173.7 parts of iron nitrate, 256.3 parts of nitrate nitrate, 74.5 parts of nickel nitrate, and 12.2 parts of zinc nitrate were sequentially added and dissolved (solution B). Liquid B was added to liquid A to form an aqueous slurry, and then 33.4 parts of antimony trioxide was aged at 80 ° C for 1 hour, and then evaporated to dryness. The cake-like material thus obtained was dried at 120 ° C, calcined at 300 ° C for 1 hour, and then pulverized. Thereafter, it was pressure-formed into a cylindrical shape having a diameter and height of 3 mm, and calcined at 500 ° C. for 6 hours to obtain catalyst C1 for producing methacrolein. The composition of this catalyst for producing methacrolein C1 excluding oxygen atoms is Mo Bi Fe Ni Co Zn W Sb Cs which is the same as the catalyst C for producing methacrolein prepared in Reference Example 3. there were.

[0078] (methacrolein production test CI)

As a result of producing methacrolein under the same reaction conditions as in the methacrolein production test C of Reference Example 3 using this catalyst C1 for producing methacrolein, the conversion rate of isobutylene was 99.8% and the selectivity of methacrolein. 88.9%, selectivity of methacrylic acid 3.2%, yield of methacrolein 86.9%, yield of methacrylic acid 3.1%, same as catalyst C for production of methacrolein in Reference Example 3 It was performance of.

[Example 4]

(Production of methacrolein production catalyst C2)

Recovery of molybdenum in Example 3 in 1000 parts of pure water After the total amount of the recovered molybdenum-containing material C2 obtained in the same manner as in C1 was dispersed, 123.5 parts of 29% by mass ammonia water was added and calorie heat was added. After stirring, 65 parts of ammonium molybdate was added and further heated and stirred. Ammonium paratungstate (1.9 parts) and cesium nitrate (17.9 parts) were added thereto and dissolved at 60 ° C (solution A). Separately, 41.8 parts of 60% by weight nitric acid aqueous solution was added to 1000 parts of pure water, and the mixture was homogenized, and then 79.9 parts of bismuth nitrate was added and dissolved. In this solution, 199.7 parts of iron nitrate, 294.7 parts of nitric nitrate, 85.7 parts of nickel nitrate, and 14.0 parts of zinc nitrate were sequentially added to dissolve (solution B). Liquid B was added to liquid A to form an aqueous slurry, and then 38.4 parts of antimony trioxide was aged at 80 ° C. for 1 hour, and then evaporated to dryness. The cake-like material thus obtained was dried at 120 ° C, calcined at 300 ° C for 1 hour, and then pulverized. Thereafter, it was pressure-molded into a cylinder with a diameter and height of 3 mm, and calcined at 500 ° C. for 6 hours to obtain catalyst C2 for producing methacrolein. The composition of this catalyst for producing methacrolein C2 excluding oxygen atoms is the same as that of the catalyst for producing methacrolein C prepared in Reference Example 3 Mo Bi Fe Ni Co Z

12 0. 7 2. 1 2. 5 4.9 n W Sb Cs.

0. 2 0. 1 0. 7 0. 6

[0080] (methacrolein production test C2)

As a result of producing methacrolein under the same reaction conditions as the methacrolein production test C of Reference Example 3 using this catalyst for producing methacrolein C2, the conversion rate of isobutylene was 97.7% and the selectivity of methacrolein. 89.2%, methacrylic acid selectivity 2.8%, methacrolein yield 87.1%, methacrylic acid yield 2.7%, same as catalyst C for production of methacrolein in Reference Example 3. Etc.

[0081] [Reference Example 4]

(Production of catalyst D for production of methacrolein)

1000 parts of pure water, 500 parts of ammonium paramolybdate, 6.2 parts of ammonium tungstate, 23.0 parts of cesium nitrate, 27.5 parts of antimony trioxide, and bismuth trioxide 33 0 parts was added and stirred with heating (Liquid A). Separately, 1000 parts of pure water, 190.7 parts of iron nitrate, 68.6 parts of nickel nitrate, 446.4 parts of cobalt nitrate, 23.5 parts of lead nitrate, and 85% by weight aqueous phosphoric acid solution 1.4 The parts were sequentially held and dissolved (B solution). After the B liquid was made into an aqueous slurry in the A liquid, the aqueous slurry was dried with a spray dryer (dryer inlet temperature: 300 ° C.). After calcining at ° C for 1 hour, it was formed into a cylinder with a diameter and height of 3 mm, and calcined at 510 ° C for 3 hours to produce methacrolein production catalyst D (composition excluding oxygen atoms: Mo Bi Fe Ni Co Pb PW Sb Cs)

12 0. 6 2 1 6. 5 0. 3 0. 05 0. 1 0. 2 0. 5

[0082] (Production test D of methacrolein D)

As a result of producing methacrolein under the same reaction conditions as in the methacrolein production test C of Reference Example 3 using this catalyst D for producing methacrolein, the conversion rate of isobutylene was 97.4% and the selectivity of methacrolein was 89. The selectivity of methacrylic acid was 3.8%, the yield of methacrolein was 87.5%, and the yield of methacrylic acid was 3.7%.

[0083] [Example 5]

(Molybdenum recovery D1)

The catalyst after the production of methacrolein of Reference Example 4 for 2000 hours was recovered. The recovered catalyst (100 parts) contains 41.3 parts of molybdenum, 0.7 parts of tungsten, 4.5 parts of bismuth, 4.0 parts of iron, 0.9 parts of antimony, 2.1 parts of nickel, and 13.8 parts of nickel. Part, 2.2 parts lead, 0.1 part phosphorus, and 2.3 parts cesium. In this recovery catalyst, the elemental yarn excluding oxygen was Mo Bi Fe Ni Co Pb P W Sb Cs. This recovered catalyst 6

12 0. 6 2 1 6. 5 0. 3 0. 05 0. 1 0. 2 0. 5

00 parts were dispersed in 2400 parts of pure water. To this was added 800 parts of 45% by weight aqueous sodium hydroxide solution and stirred at 60 ° C. for 3 hours (the pH was 12.3 at this time), and the insoluble part was filtered off. The resulting solution was neutralized with 36 mass% hydrochloric acid, and then magnesium chloride hexahydrate After adding a solution of 5 parts of pure water in 1 part and adding 29% by mass of ammonia water to adjust the pH to 9, hold at 30 ° C for 3 hours with stirring, and filter the precipitate. An aqueous solution containing molybdenum was obtained. From the molybdenum-containing aqueous solution thus obtained, a recovered molybdenum-containing precipitate (recovered molybdenum-containing material D1) was obtained in the same manner as the molybdenum recovered A1 of Example 1. The recovered molybdenum-containing material D1 contained 241.8 parts of molybdenum, 3.6 parts of tungsten, and 5.4 parts of cesium. At this time, the recovery rate of molybdenum was 97.6%.

[0084] (Production of methacrolein production catalyst D1)

After dispersing the whole amount of the resulting recovered molybdenum-containing compound D 1 above the pure water 900 parts, was heated and stirred with 29 mass ^_0/0 aqueous ammonia 126.6 parts. To this, 0.4 parts of ammonium paratungstate and 16.6 parts of cesium nitrate were added and dissolved at 60 ° C (solution A). Separately, 37.3 parts of a 60% by weight nitric acid aqueous solution was added to 900 parts of pure water, and after homogenizing, 71.3 parts of bismuth nitrate was dissolved. To this, 178.2 parts of iron nitrate, 262.8 parts of nitrate nitrate, 76.4 parts of nitrate-nickel and 12.5 parts of zinc nitrate were sequentially added and dissolved (solution B). After liquid B was mixed with liquid A to form an aqueous slurry, 34.3 parts of antimony trioxide was aged at 80 ° C for 1 hour, and then evaporated to dryness. The cake-like material thus obtained was dried at 120 ° C., calcined at 300 ° C. for 1 hour, and then pulverized. Thereafter, calo-pressure was formed into a cylindrical shape having a diameter and height of 3 mm, and calcined at 500 ° C. for 6 hours to obtain catalyst D1 for producing methacrolein. The composition excluding oxygen atoms of the catalyst D1 for producing methacrolein was the same Mo Bi Fe Ni Co Zn W Sb Cs as the catalyst C for producing methacrolein produced in Reference Example 3.

12 0. 7 2. 1 2. 5 4. 9 0. 2 0. 1 0. 7 0. 6

[0085] (methacrolein production test Dl)

As a result of producing methacrolein under the same reaction conditions as the methacrolein production test C of Reference Example 3 using this catalyst for producing methacrolein Dl, the conversion of isobutylene was 97.6% and the selectivity of methacrolein. 89. 2%, selectivity of methacrylic acid 3.0%, yield of methacrolein 87.1%, yield of methacrylic acid 2.9%, same as catalyst C for production of methacrolein in Reference Example 3 It was performance of.

[0086] [Reference Example 5]

(Manufacture of catalyst for acrylic acid production E) In 1000 parts of pure water, 100 parts of ammonium paramolybdate, 5.0 parts of ammonium tungstate, and 16.6 parts of ammonium metavanadate were dissolved. To this was added a solution of 9.5 parts of iron nitrate in 200 parts of pure water, and further, a solution of 5.5 parts of cobalt nitrate in 200 parts of pure water, and 4.1 parts of manganese nitrate in 200 parts of pure water. The solution dissolved in the part was sequentially added. Next, water glass represented by the general formula Na 0 · 2.2SiO · 2.2Η Η 3. 9 parts pure water 30 parts

2 2 2

The dissolved solution was added, and 49.6 parts of 20 mass% silica sol (dispersion medium: water) was further added. The mixture was evaporated to dryness while stirring with heating. The obtained solid was dried at 130 ° C for 16 hours, then formed into a cylindrical shape with a diameter and height of 5 mm, and calcined at 380 ° C for 5 hours to produce catalyst E (oxygen atoms) Except for: Mo V Fe Co Si Na Mn W

12 3 0. 5 0. 4 4. 3 0. 7 0. 3 0. 4

)

[0087] (Acrylic acid production test E)

The catalyst E for acrylic acid production is filled into a reaction tube, and a mixed gas of 5% by volume of acrolein, 10% by volume of oxygen, 30% by volume of steam, and 55% by volume of nitrogen is reacted at 270 ° C and contact time 3. As a result, the conversion of acrolein was 98.6%, the selectivity of acrylic acid was 95.0%, and the yield of acrylic acid was 93.7%.

[Example 6]

(Molybdenum recovery E1)

The catalyst after the acrylic acid of Reference Example 5 was produced for 2000 hours was recovered. 100 parts of this recovered catalyst contained 47.0 parts of molybdenum, 6.2 parts of vanadium, 0.7 parts of iron, 4.9 parts of silicon, 0.7 parts of sodium, 1.0 part of cobalt, and 0.7 parts of manganese. Part, and 3.0 parts tungsten. Note that the elements of the recovered catalyst except for oxygen are composed of Mo V Fe Co Si.

12 3 0. 5 0. 4 4. 3

Na Mn W. 100 parts of the recovered catalyst was dispersed in 400 parts of pure water. This

0. 7 0. 3 0. 4

To this was added 130 parts of 45% by weight sodium hydroxide / sodium hydroxide solution and stirred at 60 ° C for 3 hours (the pH was 12.4 at this time), and then the insoluble part was filtered off to obtain a solution. . Subsequently, 36% by mass hydrochloric acid was added to adjust the pH to 6.0, followed by stirring at 60 ° C. for 3 hours. The insoluble part was filtered off to obtain a molybdenum-containing aqueous solution. The molybdenum-containing aqueous solution thus obtained was passed through a weakly basic ion exchange resin (manufactured by Organone, trade name: XE-583) column. From this molybdenum-containing aqueous solution after the liquid flow, the same procedure as in Molybdenum recovery A1 in Example 1 was used for recovery. A molybdenum-containing precipitate (recovered molybdenum-containing material E1) was obtained. The recovered molybdenum-containing material E 1 contained 45.8 parts of molybdenum. At this time, the recovery rate of molybdenum was 97.4%.

[0089] (Production of acrylic acid production catalyst E1)

After dispersing the whole amount of the recovered molybdenum-containing material E1 obtained above in pure water 850 parts, was heated and stirred with 29 mass ^_0/0 aqueous ammonia 24.0 parts. In this, 4.2 parts of ammonium paratungstate and 14.0 parts of ammonium metavanadate were dissolved. To this, a solution of 8.0 parts of iron nitrate dissolved in 170 parts of pure water was added. Further, a solution of 4.6 parts of cobalt nitrate dissolved in 170 parts of pure water, and 3.5 parts of manganese nitrate were added to 170 parts of pure water. The solution dissolved in the part was sequentially added. Next, water glass represented by the general formula Na 0 · 2.2SiO · 2.2Η 3. 3. 3 parts into 25 parts pure water

2 2 2

The dissolved solution was added, and 41.8 parts of 20 mass% silica sol (dispersion medium: water) was further added. The mixture was evaporated to dryness, dried, molded and calcined in the same manner as in the production of the acrylic acid production catalyst soot in Reference Example 5 to obtain an acrylic acid production catalyst E1. The composition excluding oxygen atoms of this acrylic acid production catalyst E1 was Mo V Fe Co Si Na Mn W similar to the acrylic acid production catalyst した produced in Reference Example 5.

12 3 0. 5 0. 4 4. 3 0. 7 0. 3 0. 4

[0090] (Acrylic acid production test El)

This acrylic acid production catalyst El was used to produce acrylic acid under the same reaction conditions as in acrylic acid production test E in Reference Example 5. As a result, acrolein conversion was 98.4% and acrylic acid was selected. The rate was 95.3% and the yield of acrylic acid was 93.8%, which was the same performance as the catalyst E for acrylic acid production in Reference Example 5.

[0091] [Reference Example 6]

(Production of methacrylic acid production catalyst F)

500 parts of ammonium paramolybdate and 6.2 parts of ammonium paratungstate were dissolved at 60 ° C in 750 parts of pure water, and 9.9 parts of germanium diacid germanium were further dispersed ( A liquid). Separately, 200 parts of pure water, 27.2 parts of 85% by weight aqueous phosphoric acid solution, 11.4 parts of copper nitrate, 20.6 parts of nickel nitrate, 23.0 parts of cesium nitrate, and 19.9 parts of potassium nitrate were sequentially added. In addition, dissolved (solution B). Liquid B was added to the liquid A to form an aqueous slurry, and 16.6 parts of ammonium metavanadate were aged at 85 ° C. for 2 hours and then evaporated to dryness. Like this The cake-like material obtained in this way was dried at 120 ° C and pulverized, then formed into a cylindrical shape with a diameter and height of 3 mm, and calcined at 380 ° C for 4 hours. The composition excluding oxygen atoms: Mo P Cs KV Cu Ge Ni W) was obtained.

12 1 0. 5 0. 5 0. 6 0. 2 0. 4 0. 3 0. 1

[0092] (Production test F of methacrylic acid)

This catalyst F for producing methacrylic acid is filled in a reaction tube, and a mixed gas of 5% by volume of methacrolein, 10% by volume of oxygen, 30% by volume of water vapor and 55% by volume of nitrogen is reacted at 290 ° C and contact time is 3.6 seconds. The conversion of methacrolein was 87.5%, the selectivity of methacrylic acid was 85.6%, and the yield of methacrylic acid was 74.9%.

[Example 7]

(Production of methacrylic acid production catalyst F1)

Recovery of molybdenum in Example 1 in 710 parts of pure water Disperse the entire amount of the recovered molybdenum-containing material F1 obtained in the same manner as in A1, then add 135 parts of 29 mass% aqueous ammonia and dissolve at 60 ° C. did. In this, 0.8 parts of ammonium paratungstate was dissolved, and 9.4 parts of germanium dioxide was further dispersed (liquid A). Separately, 190 parts of pure water, 25.8 parts of 85% by weight aqueous phosphoric acid, 10.8 parts of copper nitrate, 19.5 parts of nickel nitrate, 21.8 parts of cesium nitrate and 11.0 parts of potassium nitrate Sequentially added and dissolved (solution B). A liquid B was added to the liquid A to form an aqueous slurry, and 15.7 parts of ammonium metavanadate were aged at 85 ° C. for 2 hours, and then evaporated to dryness. The cake-like material thus obtained was dried, shaped and calcined in the same manner as in the production of the methacrylic acid production catalyst F in Reference Example 6 to obtain a methacrylic acid production catalyst F1. The formation of this methacrylic acid production catalyst F1 by removing oxygen atoms is the same as the methacrylic acid production catalyst F produced in Reference Example 6 Mo P Cs K V Cu Ge Ni W

12 1 0. 5 0. 5 0. 6 0. 2 0. 4 0. 3 0.

[0094] (Methacrylic acid production test Fl)

This methacrylic acid production catalyst F1 was used to produce methacrylic acid under the same reaction conditions as methacrylic acid production test F of Reference Example 6. As a result, the methacrolein conversion rate was 87.3% and the selection of methacrylic acid. The ratio was 85.7% and the yield of methacrylic acid was 74.8%, which was the same performance as the catalyst F for producing methacrylic acid of Reference Example 6.

[Example 8] (Molybdenum recovery F2)

The catalyst after the methacrylic acid of Reference Example 6 was produced for 2000 hours was recovered. 100 parts of this recovered catalyst were 56.2 parts molybdenum, 1.5 parts phosphorus, 3.2 parts cesium, 1.0 part potassium, 1.5 parts nonadium, 0.6 parts copper, 1.4 parts germanium. , 0.9 parts of nickel and 0.9 parts of tungsten. Note that the elements of this recovered catalyst excluding oxygen are composed of Mo P

12 1

Cs K V Cu Ge Ni W. 500 parts of this recovered catalyst

0. 5 0. 5 0. 6 0. 2 0. 4 0. 3 0. 1

A molybdenum-containing aqueous solution was obtained in the same manner as in the recovery of molybdenum in Example 2 B1. After neutralizing this solution to pH 7 with 36% by mass hydrochloric acid, a solution prepared by dissolving 64.5 parts of magnesium chloride hexahydrate in 200 parts of pure water and 14.5 parts of 29% by mass ammonia water were added, and 29 Mass% aqueous ammonia was added to adjust the pH to 9, and the mixture was kept at 30 ° C. for 3 hours with stirring, and the produced precipitate and the solution (molybdenum-containing aqueous solution) were separated by filtration. From the molybdenum-containing aqueous solution thus obtained, a molybdenum-containing precipitate (recovered molybdenum-containing material F2) was obtained in the same manner as in the molybdenum recovery B1 of Example 2. The recovered molybdenum-containing material F2 contained 272.0 parts molybdenum, 6.5 parts vanadium, 3.8 parts tungsten, 1.1 parts potassium and 6.5 parts cesium. The molybdenum recovery rate at this time was 96.8%.

(Production of methacrylic acid production catalyst F2)

After the entire amount of the recovered molybdenum-containing material F2 obtained in Example 8 in pure water 750 parts were dispersed, were dissolved 29 weight ^_0/0 aqueous ammonia 142.7 parts by mosquitoes卩Ete 60 ° C. To this, 0.8 part of ammonium pantandasterate was dissolved, and 9.9 parts of germanium diacid germanium was further dispersed (solution A). Separately, 200 parts of pure water, 27.2 parts of 85 mass% phosphoric acid aqueous solution, 11.4 parts of copper nitrate, 20.6 parts of nickel nitrate, 13.5 parts of cesium nitrate, and 9.1 parts of potassium nitrate were sequentially added. It dissolved (liquid B). Liquid B was added to the liquid A to make an aqueous slurry, 1.7 parts of ammonium metavanadate was added and aged at 85 ° C for 2 hours, and then evaporated to dryness. The cake-like material thus obtained was dried, shaped and calcined in the same manner as in the production of methacrylic acid production catalyst F in Reference Example 6 to obtain methacrylic acid production catalyst F2. The composition of this catalyst F2 for producing methacrylic acid, excluding oxygen atoms, was the same Mo P Cs KV Cu Ge Ni W as the catalyst F for producing methacrylic acid produced in Reference Example 6. [0097] (Methacrylic acid production test F2)

This methacrylic acid production catalyst F2 was used to produce methacrylic acid under the same reaction conditions as in methacrylic acid production test F of Reference Example 6. As a result, the methacrolein conversion rate was 87.4% and the selection of methacrylic acid. The ratio was 85.7% and the yield of methacrylic acid was 74.9%, which was the same performance as Catalyst F for producing methacrylic acid in Reference Example 6.

Industrial applicability

[0098] According to the present invention, molybdenum can be recovered in a higher yield than a molybdenum-containing material containing at least molybdenum, so that the molybdenum-containing material after use can be used effectively. Further, by using the present invention, a catalyst can be produced from a recovered molybdenum-containing material recovered from a molybdenum-containing material containing at least molybdenum, and a molybdenum-containing material containing at least molybdenum, particularly a catalyst for acrolein production, methacrolein. The catalyst for production, the catalyst for producing acrylic acid, and the catalyst for producing methacrylic acid can be effectively utilized even after use.

Claims

The scope of the claims

[1] Molybdenum comprising a step of obtaining a molybdenum-containing aqueous solution in which at least molybdenum is dissolved in water by using a molybdenum-containing material containing at least molybdenum and containing bismuth or vanadium, an alkali, and water. Recovery method.

[2] (a) preparing a dispersion in which the molybdenum-containing material is dispersed in water;

(b) adding alkali to the dispersion to adjust the pH of the dispersion to 8 or higher;

(c) removing the dispersion liquid insoluble matter whose pH has been adjusted to 8 or more to obtain a molybdenum-containing aqueous solution in which at least molybdenum is dissolved in water;

The method for recovering molybdenum according to claim 1, comprising:

[3] (d) mixing a molybdenum-containing material containing at least molybdenum and an alkali;

(e) the obtained mixture is roasted at 600-: LOOO ° C;

(f) extracting molybdenum contained in the obtained roasted product with water to obtain a molybdenum-containing aqueous solution in which at least molybdenum is dissolved in water;

A method for recovering molybdenum, comprising:

[4] The molybdenum-containing material is a catalyst used for gas phase catalytic oxidation of propylene, nobylene, and tert-butyl alcohol! /, Which has a composition represented by the following formula (1): The method for recovering molybdenum according to any one of claims 1 to 3.

Mo Bi Fe M ¹ X ¹ Y ¹ Ζ ¹ Si Ο (1)

a b c d e f g h i

[5] The catalyst according to any one of claims 1 to 3, wherein the molybdenum-containing material is a catalyst for use in a gas phase catalytic acid of acrolein having a composition represented by the following formula (2). To recover the molybdenum.

Mo VA ² X ² Y ² Ο (2)

j k 1 m η ο

(In the formula, Μο, V and Ο represent molybdenum, vanadium and oxygen, respectively, Α ² represents at least one element selected from the group consisting of iron, cobalt, chromium, aluminum and strontium, and X ² represents germanium, shown boron, arsenic, selenium, silver, Keimoto, sodium, tellurium, lithium, antimony, phosphorus, potassium, and at least one element selected from Bariumuka Ra group consisting, Upsilon ² are magnesium, titanium And at least one element selected from the group consisting of manganese, copper, zinc, zirconium, niobium, tungsten, tantalum, calcium, tin and bismuth j, k, 1, m, n and o represents the atomic ratio of each element, and when j = 12, k = 0.01-6, 1 = 0-5, m = 0-10, n = 0-5, Necessary to satisfy the valence The number of oxygen atoms.

[6] (X) adding an acid to the molybdenum-containing aqueous solution to adjust the pH of the molybdenum-containing aqueous solution to 3 or less to produce a molybdenum-containing precipitate;

(y) separating the molybdenum-containing precipitate;

The method for recovering molybdenum according to any one of claims 1 to 5, further comprising:

[7] Using the molybdenum-containing aqueous solution obtained by the molybdenum recovery method according to any one of claims 1 to 5, or the molybdenum-containing precipitate obtained by the molybdenum recovery method according to claim 6, A method for producing a catalyst, comprising producing a catalyst containing at least molybdenum.

8. The method for producing a catalyst according to claim 7, wherein another molybdenum raw material is used in combination.