JPH08266899A - Ammoxidation catalyst composition and production of nitrile compound using the same - Google Patents

Abstract

PURPOSE: To attain a high yield for hydrocyanic acid as well as acrylonitrile or methacrylonitrile and to suppress the reduction of the activity of a catalyst by using an ammoxidation catalyst represented by a specified formula when a nitrile compd. is produced by allowing propylene, isobutene or tert. butanol to react with molecular oxygen and ammonia. CONSTITUTION: This ammoxidation catalyst is represented by the formula, wherein X is one or more kinds of elements selected from among rare earth elements and yttrium, Y is one or more kinds of elements selected from among Ni, Co, Mn, Cr, In, Mg, Ca, Sr, Ba, Zn, Na and P, A is one or more kinds of elements selected from among K, Rb, Cs and Tl, (a), (b), (c), (d), (e), (f) and (g) show the atomic ratio of Mo:Bi:Fe:X:Y:A:O, 10<=a<=14, 0.001<=b<0.1, 0.1<=c<=4, 0.001<=d<=2, 0.1<=e<=12, 0.01<=f<=1.0 and (g) is the number of O atoms satisfying the valence requirements of the other elements.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ammoxidation catalyst composition used for producing a nitrile compound by reacting propylene, isobutene or tertiary butanol with molecular oxygen and ammonia. The present invention relates to a method for producing a nitrile compound.

[0002]

The reaction of propylene, isobutene or tertiary butanol with molecular oxygen and ammonia,
A method for producing a nitrile compound such as acrylonitrile, methacrylonitrile, acetonitrile and hydrocyanic acid by a so-called ammoxidation reaction is well known, and many catalysts used for this ammoxidation reaction have been proposed. For example, Japanese Patent Publication No. 38-17967 discloses molybdenum,
An oxide catalyst containing bismuth and iron is disclosed in JP-B-38-1.
No. 9111 proposes oxide catalysts containing antimony and iron, and these catalyst systems have been continuously improved from various viewpoints.

Among these improvements, the catalyst composition in the region where the Bi composition ratio is small is described in JP-B-57-2.
No. 6591 discloses a catalyst composed of an element selected from phosphorus, arsenic and bismuth in addition to molybdenum, cobalt and iron, and Japanese Patent Publication No. 59-50667 discloses molybdenum,
Germanium, tin, copper in addition to bismuth, iron, nickel and / or cobalt, potassium or cesium,
A catalyst composed of an element selected from silver, chromium, ruthenium, boron, gallium, indium, manganese, antimony, thorium, zirconium and yttrium is disclosed.

Regarding catalyst compositions using rare earth elements containing cerium, Japanese Patent Laid-Open Nos. 49-101331 and 57-180431 disclose molybdenum, bismuth, cerium, alkali metals, thallium, etc. Japanese Patent Publication No. 61-43094 discloses a catalyst containing the above element as a catalyst made of molybdenum, tungsten, bismuth and cerium. Further, Japanese Patent Publication No. 58-38424 discloses an oxide catalyst containing molybdenum, tellurium and cerium and one or more elements selected from iron, chromium, aluminum and bismuth, and Japanese Patent Publication No. 51-33888 discloses molybdenum. , Bismuth, iron, and at least one element selected from nickel and cobalt, and an alkali metal, a rare earth element,
An oxide catalyst composed of one or more elements selected from tantalum and niobium has a basic component of molybdenum, bismuth and iron in Japanese Patent Publication No. 61-26419 and contains cerium, lanthanum, neodymium, praseodymium, samarium,
An oxide catalyst containing at least one element selected from europium and gadolinium and at least one element selected from potassium, rubidium and cesium, and further disclosed in JP-A-59-204163 is molybdenum, bismuth, In addition to phosphorus and silicon, iron, cobalt, nickel,
JP-A-7-48334 discloses a catalyst containing two or more elements selected from copper, zirconium and potassium and one or more elements selected from manganese, cerium, thorium, yttrium, lanthanum and thallium. A catalyst containing a mixture of praseodymium and neodymium in addition to molybdenum, bismuth, iron and nickel is disclosed in Japanese Patent Application No. 6-206135, which is composed of molybdenum, bismuth and elements added to cerium, iron and nickel and an alkali metal. Oxide catalysts are disclosed.

[0005]

The catalyst disclosed above has greatly improved the yield of acrylonitrile or methacrylonitrile, but in the region where the composition ratio of Bi is small, the yield of hydrocyanic acid in addition to acrylonitrile or methacrylonitrile is improved. Regarding the decrease in activity, it is not yet fully satisfactory.

The present invention is to provide a catalyst which gives a high yield of hydrocyanic acid in addition to acrylonitrile or methacrylonitrile, and which is also improved in terms of preventing a decrease in activity.

[0007]

[Means for Solving the Problems] As a result of extensive studies for solving the above problems, as an oxide catalyst, a general formula of Mo _a Bi _b Fe _c X _d Y _e A _f O _g (wherein X is a rare earth element) is obtained. One or more elements selected from elements and yttrium, Y is nickel, cobalt, manganese, chromium, indium, magnesium, calcium,
One or more elements selected from strontium, barium, zinc, sodium and phosphorus, A is one or more elements selected from potassium, rubidium, cesium and thallium, a, b, c, d, e, f and g are Representing the atomic ratio of molybdenum, bismuth, iron, X component, Y component, A component and oxygen, a is 10 to 14 and b is 0.0.
01 or more and less than 0.1, c is 0.1 to 4, d is 0.00
1-2, e is 0.1-12, f is 0.01-1.0, g
Is the number of oxygen atoms required to satisfy the valence requirements of the other elements present. ), The oxide represented by
When propylene, isobutene or tertiary butanol is reacted with molecular oxygen and ammonia to produce acrylonitrile or methacrylonitrile, a high yield of cyanic acid in addition to acrylonitrile or methacrylonitrile is obtained, and the activity is high. The present invention has been completed by discovering that the decrease in the temperature can be prevented.

That is, the present invention provides a catalyst composition for ammoxidation which can give a high yield of cyanide in addition to acrylonitrile or methacrylonitrile in a region where the composition ratio of Bi is small, and can prevent a decrease in activity. The present invention provides a method for producing a nitrile compound used.
The composition of the oxide catalyst of the present invention has an atomic ratio of bismuth of 0.001 or more and less than 0.1, preferably 0.00.
5 to 0.095, more preferably 0.01 to 0.09,
In addition, the X component, which is one or more kinds of elements selected from rare earth elements and yttrium, is 0.001 to 2, preferably 0.005 to 1, and more preferably 0.01 to 0.5. To do.

As the X component, at least one element selected from cerium, neodymium, praseodymium, lanthanum, samarium and yttrium is preferable, and at least one element selected from cerium, neodymium and praseodymium is particularly preferable. If the bismuth is less than 0.001, the activity is low and the yield of acrylonitrile or methacrylonitrile is reduced. When bismuth is 0.1 or more, the yield of acrylonitrile or methacrylonitrile is high, but the yield of hydrocyanic acid is low.

With respect to the X component, if it is less than 0.001, the activity decreases with the progress of the reaction. If the X component is larger than 2, the yield of acrylonitrile or methacrylonitrile decreases. That is, the composition ratio of bismuth is 0.001
In a very small composition range of less than 0.1 above, it is surprising that the condition that the X component, which is one or more elements selected from rare earth elements and yttrium, is 0.001 to 2 is surprising. It has been found that, in addition to acrylonitrile or methacrylonitrile, a high yield can be obtained for hydrocyanic acid, and an improved catalyst can be provided in terms of prevention of activity decrease.

For other compositions of the oxide catalyst of the present invention, the atomic ratio of molybdenum is 10-14, preferably 11-13, iron is 0.1-4, preferably 0.5-.
3, the ratio of the Y component representing one or more elements selected from nickel, cobalt, manganese, chromium, indium, magnesium, calcium, strontium, barium, zinc, sodium and phosphorus is 0.1-12, preferably 1- Further, the component Y is preferably at least one element selected from nickel, cobalt, manganese, chromium, magnesium and zinc. The ratio of the component A representing one or more elements selected from potassium, rubidium, cesium and thallium is 0.01 to 1.
It is 0, preferably 0.05 to 0.5.

As the carrier of the oxide catalyst of the present invention, oxides of silica, alumina, titania, zirconia and the like are used, and silica is used as a suitable carrier. The carrier is preferably used in the range of 30 to 70% by weight, preferably 40 to 60% by weight. The oxide catalyst of the present invention can be obtained by a known method, for example, by preparing raw materials, spray-drying the prepared solution, and finally calcining the dried product. When preparing the raw materials, it is preferable to use silica sol for silica, ammonium salt for molybdenum, and water-soluble compounds such as nitrate as other components. The atomization in the spray drying of the raw material liquid is preferably a centrifugal method, and the drying temperature is 100 to 400 ° C, preferably 150 to 300 ° C. If necessary, the dried product is pre-baked at 150 to 500 ° C, and then 500 to 750 ° C, preferably 550 to 550 ° C.
It is carried out in the temperature range of 700 ° C. for 1 to 20 hours.

Propylene using the oxide catalyst of the present invention,
The production of nitrile compounds by the reaction of isobutene or tertiary butanol with molecular oxygen and ammonia can be carried out in either a fluidized bed reactor or a fixed bed reactor.
Preference is given to working in a fluidized bed reactor. The raw materials propylene, isobutene, tertiary butanol and ammonia do not necessarily have to be highly pure, and industrial grade ones can be used.

Further, although it is usually preferable to use air as the oxygen source, it is also possible to use a gas whose oxygen concentration is increased by mixing oxygen with air. The composition of the raw material gas is such that the molar ratio of ammonia and air to propylene, isobutene or tertiary butanol is (propylene, isobutene or tertiary butanol) / ammonia / air = 1/0.
8 to 1.4 / 7 to 12, preferably 1 / 0.9 to 1.3
The range is / 8 to 11.

The reaction temperature is 350 to 550 ° C., preferably 400 to 500 ° C., and the reaction pressure is normal pressure to 3 atm. The contact time between the raw material gas and the catalyst is 0.5 to 20.
(Sec · g / cc), preferably 1 to 10 (sec · g
g / cc).

[0016]

The present invention will be described in detail below with reference to examples. In the examples and comparative examples, the conversion rate and the yield used to express the reaction results are defined by the following equations. Conversion (%) = (number of moles of reacted propylene, isobutene or tertiary butanol) / (supplied propylene,
Number of moles of isobutene or tertiary butanol) * 100 Acrylonitrile yield (%) = (number of moles of acrylonitrile produced) / (number of moles of propylene supplied) * 1
00 Yield of hydrocyanic acid (%) = 1/3 * (number of moles of hydrocyanic acid formed) /
(The number of moles of propylene supplied) * 100 In addition, the reactor is a 10-mesh wire net at 1 cm intervals.
Using a fluidized bed reaction tube made of bi-cold glass with an inner diameter of 25 mm, which contained two sheets, the amount W of the packed catalyst was 50 g, the reaction pressure P was 0.5 Kg / cm ² G, and the total supply gas amount F was 4.0 to 6.
The reaction temperature T is 430 at 0 cc / sec (NTP conversion).
Performed at ° C.

The contact time is defined by the following equation. Contact time (sec · g / cc) = (W / F) * 273 /
(273 + T) * (1.03 + P) /1.03 The composition of the supplied reaction gas is propylene / ammonia / air = 1 / 1.1 / 8.0 during the ammoxidation reaction of propylene.
The composition of the air is such that the oxygen concentration at the outlet of the reactor is 0.05.
A value such that ˜0.2% by volume was appropriately selected and used.

[0018]

Example 1 Composition is Mo₁₂Bi_0.04Ce_0.08Fe_2.0C
o_8.0K_0.20The oxide represented by 50% by weight of silica
The catalyst supported on was prepared as follows. 30 wt%
SiO₂Take 1666.7 g of silica sol containing
3.9 wt% nitric acid 375.8 g and 3.9 g bis nitrate bis
Mass [Bi (NO₃)₃・ 5H₂O], 6.9 g of sodium nitrate
Lithium [Ce (NO₃)₃・ 6H₂O], 160.4 g
Iron nitrate [Fe (NO₃)₃・ 9H₂O], 462.4 g
Cobalt nitrate [Co (NO₃) ₂・ 6H₂O] and 4.
0 g of potassium nitrate [KNO₃] Is added to the solution
Finally, 420.6g of Paramorib in 847.2g of water
Ammonium decanoate [(NH_Four)₆Mo₇O_{twenty four}・ 4H₂O]
Was added to the solution. The raw material mixture obtained here
It was sent to a co-current type spray dryer and dried at about 200 ° C.
The atomization of the preparation liquid is performed by a plate type rotating machine installed in the center of the upper part of the dryer.
It was carried out using an atomizer equipped with a trochanter. The powder obtained
Is preheated in an electric furnace at 400 ° C for 1 hour, then at 550 ° C
It was calcined for 2 hours to obtain a catalyst.

Contact time of 6. with 50 g of the catalyst obtained.
When the ammoxidation reaction of propylene was carried out at 0 (sec · g / cc), the conversion rate after 20 hours from the start of the reaction was 9
8.5%, acrylonitrile yield is 77.0%, hydrocyanic acid yield is 6.2%, conversion rate after 120 hours is 98.2%, acrylonitrile yield is 76.8%, hydrocyanic acid yield is 6. 0%
Met.

[0020]

Examples 2 to 4 and Comparative Examples 1 to 2 In the same manner as in Example 1, the oxides having the compositions shown in Table 1 were mixed with 50% by weight of silica.
The catalyst supported on was manufactured, and the ammoxidation reaction of propylene was carried out. The results are shown in Table 1.

[0021]

[Table 1]

[0022]

INDUSTRIAL APPLICABILITY The catalyst of the present invention gives a high yield not only of acrylonitrile or methacrylonitrile but also of hydrocyanic acid in the production of a nitrile compound in the ammoxidation reaction of propylene, isobutene or tertiary butanol, and decreases the activity. Was also achieved at the same time.

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Claims (2)

[Claims] 1. An oxide catalyst having a general formula of Mo _a Bi _b Fe _c X _d Y _e A _f O _g (wherein X is at least one element selected from rare earth elements and yttrium, and Y is nickel or cobalt). , Manganese, chromium, indium, magnesium, calcium,
One or more elements selected from strontium, barium, zinc, sodium and phosphorus, A is one or more elements selected from potassium, rubidium, cesium and thallium, a, b, c, d, e, f and g are Representing the atomic ratio of molybdenum, bismuth, iron, X component, Y component, A component and oxygen, a is 10 to 14 and b is 0.0.
01 or more and less than 0.1, c is 0.1 to 4, d is 0.00
1-2, e is 0.1-12, f is 0.01-1.0, g
Is the number of oxygen atoms required to satisfy the valence requirements of the other elements present. A) Ammoxidation catalyst composition for producing a nitrile compound by reacting propylene, isobutene or tertiary butanol represented by) with molecular oxygen and ammonia. 2. A catalyst composition for ammoxidation according to claim 1, which is used when a nitrile compound is produced by reacting propylene, isobutene or tertiary butanol with molecular oxygen and ammonia. Method for producing nitrile compound.