JP4182324B2 - Production method of aromatic amine production catalyst - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a process for producing a catalyst used in producing an aromatic amine by hydrogenating an aromatic nitrile. Aromatic amines are useful as raw materials for producing curing agents, synthetic resins, isocyanates and the like.
[0002]
[Prior art]
For hydrogenation of aromatic nitriles, catalyst systems using various metals have been proposed. For example, JP-A-51-101930 describes a method for producing benzylamine and dibenzylamine from benzonitrile. At this time, Raney nickel pellets, zirconium-promoter-reduced nickel supported on diatomaceous earth tablets, and platinum supported on alumina tablets are used as the catalyst. Japanese Patent Application Laid-Open No. 62-129257 describes a process for producing benzylamine in which benzonitrile is hydrogenated using Raney nickel or Raney cobalt in the presence of ammonia. Japanese Patent Application Laid-Open No. 5-97776 describes a method for obtaining benzylamine by hydrogenating benzonitrile using a cobalt-alumina catalyst. In JP-A-9-40630 and JP-A-10-202048, Raney catalyst containing nickel and / or cobalt is used to hydrogenate only one of two nitrile groups of an aromatic dinitrile, and aromatic cyanomethyl. A method for producing amines is described.
[0003]
These methods have the advantage that the yield of aromatic amine is high, but in any catalyst, high boiling point by-products generated during the reaction adhere to the catalyst, and the target amine yield decreases. In addition, hydrocracking as an activation regeneration operation performed after the decrease in activity causes rapid methane generation and catalyst collapse due to evaporation of liquid ammonia, resulting in an increase in the reaction differential pressure and a very long catalyst life. Short.
[0004]
[Problems to be solved by the invention]
An object of the present invention is to provide an aromatic amine production catalyst that can be used for a long period of time without degradation due to rapid methane generation and liquid ammonia evaporation due to hydrocracking as an activation regeneration operation performed after a decrease in activity. It is to provide a manufacturing method.
[0005]
[Means for Solving the Problems]
As a result of intensive studies on the above problems, the present inventors have prepared a precipitate obtained by adding an aqueous solution of a soluble salt of a metal component and a carrier to an alkaline aqueous solution and then shaping the precipitate as it is without drying. The present inventors have found that the catalyst is a catalyst that has no rapid methane generation due to hydrocracking as an activation regeneration operation performed after a decrease in activity and no collapse due to evaporation of liquid ammonia. That is, the present invention provides a precipitate obtained by adding a mixed aqueous solution of Ni and / or Co as a metal component and a soluble salt of silica, alumina, silica-alumina, titania and / or zirconia as a support to an aqueous alkaline solution. Or by adding a soluble salt aqueous solution of each of the metal component and the carrier separately to the alkaline aqueous solution and filtering the resulting mixture of precipitates, without drying the resulting 30% to 90% by weight precipitate. The present invention relates to a process for producing an aromatic amine production catalyst, which is molded as it is, dried, calcined and then reduced with hydrogen .
[0006]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be specifically described below.
Ni and / or Co is used as the metal component of the catalyst of the present invention.
As additional active ingredients, Li, Na, K, Rb, Cs, Be, Ca, Ba, Ti, Cu, Cr, Zn, Mn, Mg, Fe, Ga, Ge, Nb, Ru, Rh, Pd, Ir At least one metal component selected from the group consisting of Pt, Bi, Al, Si, In, Sr, Ce, and Mo can be used.
[0007]
As the soluble salt of the metal component of the present invention, an acidic salt is preferably used. For example, nitrates, sulfates, hydrochlorides, acetates and formates are used, and nitrates are preferably used.
[0008]
As the carrier of the present invention, a carrier that easily forms a gel, for example, silica, alumina, silica-alumina, titania, zirconia, and a combination thereof is used, and these are used for catalyst preparation in the form of a soluble salt. .
[0009]
In the alkaline aqueous solution of the present invention, alkali metal, alkaline earth metal and ammonium alkali hydroxide, alkali carbonate and hydrogen carbonate alkali are used.
[0010]
The catalyst of the present invention is obtained by adding a mixed aqueous solution of a soluble salt of a metal component and a carrier to an aqueous alkaline solution, or separately adding an aqueous soluble salt solution of each of the metal component and the carrier to an aqueous alkaline solution. The precipitate mixture thus obtained is filtered, and the obtained precipitate having a water content of 30 to 90% by weight is formed as it is without being dried. If the water content is higher than this, the catalyst shape cannot be maintained during molding, and if it is lower than this, the binding force of the carrier cannot be maintained, and a sufficiently strong catalyst cannot be obtained. Sudden generation of methane due to hydrocracking as an activation regeneration operation and catalyst collapse due to evaporation of liquid ammonia occur.
By molding without drying, the binding strength of the carrier is maintained and a strong catalyst can be obtained. When dried and molded by adding a binder or water, the carrier binding strength is not maintained, and a sufficiently strong catalyst cannot be obtained. Therefore, rapid methane by hydrocracking as an activation regeneration operation performed after the activity is reduced. And catalyst collapse due to evaporation of liquid ammonia occurs.
[0011]
In the present invention, the proportion of the support in the catalyst is in the range of 20 to 80% by weight. If the ratio of the carrier is less than this range, rapid methane generation due to hydrocracking as an activation regeneration operation performed after the activity declines, and catalyst collapse due to evaporation of liquid ammonia occurs. As a result, a sufficient amine yield cannot be obtained.
[0012]
In the present invention, the catalyst is produced by a coprecipitation method or a kneading method for precipitation of each component. For example, when preparing a catalyst in which Ni is supported on a zirconia support, an aqueous nickel salt solution such as nickel nitrate and nickel sulfate is poured into an aqueous ammonium hydrogen carbonate solution to obtain a nickel carbonate slurry, and zirconium nitrate is added to the slurry. Then, an aqueous zirconium salt solution such as zirconium sulfate and an aqueous ammonium hydrogen carbonate solution are simultaneously poured to deposit zirconium carbonate to obtain a precipitated slurry. The precipitate slurry is filtered to obtain a precipitate.
[0013]
The catalyst of the present invention can be molded by a wet granulation method that has been put into practical use industrially. For example, an extrudate or extrudate produced by the method described in paragraphs 18 to 32 of the Chemical Engineering Special Issue Factory Operation Series (Granulation Edition) (issued in 1963 by Kagaku Kogyo Co., Ltd.) For example, a molded product that is sized with a sizing machine is used. After the precipitate is filtered, a precipitate having a water content of 30 to 90% by weight is formed as it is, dried at 30 to 150 ° C., and then fired. The catalyst can be washed either after filtration of the precipitated slurry or after drying.
[0014]
Firing is carried out for several hours or more in an air atmosphere at 200 to 500 ° C., preferably 250 to 450 ° C., on the molded dry product. The molded body obtained by the above method is subjected to hydrogen reduction. Reduction is 200 to 600 ° C., preferably 200 to 500 ° C., SV = 100 to 1000 Hr ⁻¹ , preferably ¹ to 80%, preferably 1 to 60% in hydrogen gas (the rest is an inert gas such as nitrogen gas) for several hours. Do.
[0015]
The catalyst of the present invention can be suitably used when an aromatic nitrile compound is hydrogenated to produce an aromatic amine.
The aromatic nitrile compound is an aromatic nitrile such as benzonitrile, phthalonitrile, isophthalonitrile, terephthalonitrile or the like having one or more cyano groups on the aromatic ring. The raw material aromatic nitrile compound may contain a substituent not involved in the reaction. Examples of the substituent not involved in the reaction include an alkyl group, an alkoxy group, a halogen group, an amino group, an amide group, and a hydroxyl group. In the hydrogenation reaction of an aromatic nitrile, the reactivity varies greatly depending on the substituents on the aromatic ring. However, when the catalyst of the present invention is used, the reaction proceeds efficiently even for those having these substituents.
For the reaction, either a batch method or a flow method can be used. Reaction temperature is 20-200 degreeC, Preferably it is the range of 40-180 degreeC. If the reaction temperature is lower than this range, the conversion rate of the starting nitriles is low. On the other hand, if the reaction temperature is higher than this range, the production of high-boiling compounds of the target amines increases, so that the yield of the target products decreases.
The contact time between the reaction liquid and the catalyst varies depending on the type of raw material, the raw material, the solvent and hydrogen charging composition, the reaction temperature and the reaction pressure, but is usually in the range of 0.1 to 5.0 hours.
In the present invention, the reaction product is separated from the solvent and recovered using a known method. For example, after the gas component and the liquid component are separated from the reaction system, the liquid component is recovered and recovered by distillation.
[0016]
【Example】
Next, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited by these examples.
[0017]
Example 1
(Catalyst preparation) 251.6 g of ammonium hydrogen carbonate NH ₄ HCO ₃ was dissolved in 1.8 kg of pure water, and the temperature was raised to 40 ° C. and held well with stirring. Nickel nitrate hexahydrate Ni (NO ₃ ) ₂ · 6H ₂ O 255.1 g, copper nitrate trihydrate Cu (NO ₃ ) ₂ · 3H ₂ O 15.0 g, chromium nitrate nonahydrate Cr (NO ₃ ) and ₃ · _9H 2 _O30.3g and zirconium nitrate aqueous solution 189.3g containing 25 wt% as ZrO ₂ were dissolved in 40 ° C. pure water of 1.5 kg, the mixed metal solution was prepared. The mixed metal aqueous solution maintained at 40 ° C. was added to the aqueous ammonium hydrogen carbonate solution with good stirring to prepare a precipitation slurry. The slurry was heated to 80 ° C. and held at the same temperature for 30 minutes. The precipitate slurry was washed by filtration to obtain a precipitate having a water content of 70% by weight. This precipitate was extruded at 3.0 mmφ, dried at 110 ° C. overnight, and baked in an air atmosphere at 380 ° C. for 18 hours. This molded product was reduced at 400 ° C. in a hydrogen stream.
[0018]
(Catalyst decay test) In a 100 ml autoclave, 50 of the above catalyst and 10 g of liquid ammonia were charged, heated to 120 ° C. and allowed to stand for 18 hours. Thereafter, when the catalyst was extracted, no cracks or cracks were found in the catalyst.
[0019]
(Catalyst activity test) A 100 ml autoclave was charged with 3.2 g of isophthalonitrile, 10.4 g of mesitylene, 10.0 g of liquid ammonia and 2.0 g of the above catalyst, and pressurized to 10.8 MPa (gauge) with hydrogen. The autoclave was shaken at 120 ° C. until no change in pressure was observed. When this product solution was analyzed, the conversion rate of isophthalonitrile was 99.3 mol%, and the yield of metaxylylenediamine was 78.6 mol%.
[0020]
Example 2
(Catalyst activity test) A 100 ml autoclave was charged with 3.2 g of terephthalonitrile, 10.4 g of mesitylene, 10.0 g of liquid ammonia and 2.0 g of the catalyst prepared in Example 1 , and hydrogen was added to 10.8 MPa (gauge). Pressurized. The autoclave was shaken at 120 ° C. until no change in pressure was observed. When this product solution was analyzed, the conversion rate of terephthalonitrile was 99.4 mol%, and the yield of paraxylylenediamine was 81.2 mol%.
[0021]
Example 3
(Catalyst preparation) 168.7 g of sodium carbonate Na ₂ CO ₃ was dissolved in 1.4 kg of pure water, and the temperature was raised to 40 ° C. and held well with stirring. Nickel nitrate hexahydrate Ni (NO ₃ ) ₂ · 6H ₂ O 255.1 g, copper nitrate trihydrate Cu (NO ₃ ) ₂ · 3H ₂ O 15.0 g, chromium nitrate nonahydrate Cr (NO ₃ ) and ₃ · _9H 2 O 30.3g and zirconium nitrate aqueous solution 189.3g containing 25 wt% as ZrO ₂ were dissolved in 40 ° C. pure water of 1.5 kg, the mixed metal solution was prepared. The mixed metal aqueous solution kept at 40 ° C. was added to the sodium carbonate aqueous solution with good stirring to prepare a precipitation slurry. The slurry was heated to 80 ° C. and held at the same temperature for 30 minutes. The precipitate slurry was washed by filtration to obtain a precipitate having a water content of 74% by weight. This precipitate was extruded at 3.0 mmφ, dried at 110 ° C. overnight, and baked in an air atmosphere at 380 ° C. for 18 hours. This molded product was reduced at 400 ° C. in a hydrogen stream.
[0022]
(Catalyst decay test) In a 100 ml autoclave, 50 of the above catalyst and 10 g of liquid ammonia were charged, heated to 120 ° C. and allowed to stand for 18 hours. Thereafter, when the catalyst was extracted, no cracks or cracks were found in the catalyst.
[0023]
(Catalyst activity test) A 100 ml autoclave was charged with 3.2 g of isophthalonitrile, 10.4 g of mesitylene, 10.0 g of liquid ammonia and 2.0 g of the above catalyst, and pressurized to 10.8 MPa (gauge) with hydrogen. The autoclave was shaken at 120 ° C. until no change in pressure was observed. When this product solution was analyzed, the conversion rate of isophthalonitrile was 99.0 mol%, and the yield of metaxylylenediamine was 77.3 mol%.
[0024]
Example 4
(Catalyst activity test) A 100 ml autoclave was charged with 3.2 g of terephthalonitrile, 10.4 g of mesitylene, 10.0 g of liquid ammonia and 2.0 g of the catalyst prepared in Example 3, and the hydrogen was adjusted to 10.8 MPa (gauge). Pressurized. The autoclave was shaken at 120 ° C. until no change in pressure was observed. When this product solution was analyzed, the conversion of terephthalonitrile was 99.7 mol%, and the yield of paraxylylenediamine was 80.6 mol%.
[0025]
Example 5
(Catalyst preparation) 47.84 g of ammonium hydrogen carbonate NH ₄ HCO ₃ was dissolved in 1.0 kg of pure water, and the temperature was raised to 40 ° C. and held well with stirring. 160.0 g of nickel nitrate hexahydrate Ni (NO ₃ ) ₂ .6H ₂ O was dissolved in 1.0 kg of pure water at 40 ° C. to prepare a metal aqueous solution. The aqueous metal solution maintained at 40 ° C. was added to the aqueous ammonium hydrogen carbonate solution with good stirring to prepare a nickel carbonate precipitation slurry and maintained at 40 ° C. Further, 57.68 g of sodium silicate containing 56.0 wt% as SiO ₂ and 20.0 wt% as Na ₂ O was dissolved in 608 g of pure water at 40 ° C. to prepare a sodium silicate aqueous solution. Further, 38.21 g of 61.0 wt% nitric acid HNO ₃ was dissolved in 344 g of pure water at 40 ° C. to prepare a nitric acid aqueous solution. The sodium silicate aqueous solution and the nitric acid aqueous solution were simultaneously poured into a nickel carbonate precipitation slurry to deposit silica. The slurry was heated to 80 ° C. and held at the same temperature for 30 minutes. The precipitate slurry was washed by filtration to obtain a precipitate having a water content of 87% by weight. This precipitate was extruded at 3.0 mmφ, dried at 110 ° C. overnight, and baked in an air atmosphere at 380 ° C. for 18 hours. This molded product was reduced at 400 ° C. in a hydrogen stream.
[0026]
(Catalyst decay test) In a 100 ml autoclave, 50 of the above catalyst and 10 g of liquid ammonia were charged, heated to 120 ° C. and allowed to stand for 18 hours. Thereafter, when the catalyst was extracted, no cracks or cracks were found in the catalyst.
[0027]
(Catalyst activity test) A 100 ml autoclave was charged with 3.2 g of isophthalonitrile, 10.4 g of mesitylene, 10.0 g of liquid ammonia and 2.0 g of the above catalyst, and pressurized to 10.8 MPa (gauge) with hydrogen. The autoclave was shaken at 120 ° C. until no change in pressure was observed. When this product solution was analyzed, the conversion rate of isophthalonitrile was 98.7 mol%, and the yield of metaxylylenediamine was 79.6 mol%.
[0028]
Example 6
(Catalyst activity test) A 100 ml autoclave was charged with 3.2 g of terephthalonitrile, 10.4 g of mesitylene, 10.0 g of liquid ammonia and 2.0 g of the catalyst prepared in Example 5 , and hydrogen was added to 10.8 MPa (gauge). Pressurized. The autoclave was shaken at 120 ° C. until no change in pressure was observed. When this product solution was analyzed, the conversion of terephthalonitrile was 99.9 mol%, and the yield of paraxylylenediamine was 81.2 mol%.
[0029]
Comparative Example 1
(Catalyst preparation) The precipitate slurry prepared in Example 1 was filtered and washed, and then subjected to suction filtration so that the water content was 20% by weight. This precipitate was extruded at 3.0 mmφ, dried at 110 ° C. overnight, and baked in an air atmosphere at 380 ° C. for 18 hours. This molded product was reduced at 400 ° C. in a hydrogen stream.
[0030]
(Catalyst decay test) In a 100 ml autoclave, 50 of the above catalyst and 10 g of liquid ammonia were charged, heated to 120 ° C. and allowed to stand for 18 hours. Thereafter, when the catalyst was extracted, cracks and cracks were found in 35 catalysts.
[0031]
(Catalyst activity test) A 100 ml autoclave was charged with 3.2 g of isophthalonitrile, 10.4 g of mesitylene, 10.0 g of liquid ammonia and 2.0 g of the above catalyst, and pressurized to 10.8 MPa (gauge) with hydrogen. The autoclave was shaken at 120 ° C. until no change in pressure was observed. When this product solution was analyzed, the reaction rate of isophthalonitrile was 99.3 mol%, and the yield of metaxylylenediamine was 78.3 mol%.
[0032]
Comparative Example 2
(Catalyst activity test) A 100 ml autoclave was charged with 3.2 g of terephthalonitrile, 10.4 g of mesitylene, 10.0 g of liquid ammonia and 2.0 g of the catalyst prepared in Comparative Example 1, and adjusted to 10.8 MPa (gauge) with hydrogen. Pressurized. The autoclave was shaken at 120 ° C. until no change in pressure was observed. When this product solution was analyzed, the conversion of terephthalonitrile was 99.8 mol%, and the yield of paraxylylenediamine was 82.3 mol%.
[0033]
Comparative Example 3
(Catalyst preparation) The precipitate slurry prepared in Example 1 was filtered and washed, and then dried until the water content became 10% by weight. Water was added to the dried product to a moisture content of 70% by weight. This precipitate was extruded at 3.0 mmφ, dried at 110 ° C. overnight, and baked in an air atmosphere at 380 ° C. for 18 hours. This molded product was reduced at 400 ° C. in a hydrogen stream.
[0034]
(Catalyst decay test) In a 100 ml autoclave, 50 of the above catalyst and 10 g of liquid ammonia were charged, heated to 120 ° C. and allowed to stand for 18 hours. Thereafter, when the catalyst was extracted, cracks and cracks were observed in 20 catalysts.
[0035]
(Catalyst activity test) A 100 ml autoclave was charged with 3.2 g of isophthalonitrile, 10.4 g of mesitylene, 10.0 g of liquid ammonia and 2.0 g of the above catalyst, and pressurized to 10.8 MPa (gauge) with hydrogen. The autoclave was shaken at 120 ° C. until no change in pressure was observed. When this product solution was analyzed, the isophthalonitrile reaction rate was 99.0 mol% and the metaxylylenediamine yield was 79.2 mol%.
[0036]
Comparative Example 4
(Catalyst activity test) A 100 ml autoclave was charged with 3.2 g of terephthalonitrile, 10.4 g of mesitylene, 10.0 g of liquid ammonia and 2.0 g of the catalyst prepared in Comparative Example 3 , and hydrogen was adjusted to 10.8 MPa (gauge). Pressurized. The autoclave was shaken at 120 ° C. until no change in pressure was observed. When this product solution was analyzed, the conversion of terephthalonitrile was 99.9 mol%, and the yield of paraxylylenediamine was 81.1 mol%.
[0037]
【The invention's effect】
When the aromatic amine is produced, by using the catalyst of the present invention, the catalyst collapse caused by hydrocracking as the activation regeneration operation is suppressed, and the catalyst can be used for a long period of time.
Therefore, by using the catalyst of the present invention, an aromatic amine can be produced from an aromatic nitrile very economically, and the industrial significance of the present invention is great.

Claims (3)

A precipitate obtained by adding a mixed aqueous solution of Ni and / or Co as a metal component and a soluble salt of silica, alumina, silica-alumina, titania and / or zirconia as a carrier to an alkaline aqueous solution, or a metal component The mixture of precipitates obtained by adding each soluble salt aqueous solution of the carrier separately to the aqueous alkaline solution is filtered, and the resulting precipitate having a water content of 30 to 90% by weight is molded as it is without drying, and dried. A method for producing an aromatic amine production catalyst, characterized by hydrogen reduction after calcination . (1) Ni and / or Co, and (2) Li, Na, K, Rb, Cs, Be, Ca, Ba, Ti, Cu, Cr, Zn, Mn, Mg, Fe, Ga, Ge, 2. The process for producing an aromatic amine production catalyst according to claim 1, which is at least one selected from the group consisting of Nb, Ru, Rh, Pd, Ir, Pt, Bi, Al, Si, In, Sr, Ce and Mo. . The process for producing an aromatic amine production catalyst according to claim 1 or 2, wherein the soluble salt of the metal component is an acidic salt.