JP2002097015A - Method for producing hydrogen cyanide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing hydrogen cyanide by ammoxidation of methanol with a high yield over a long period of time. In producing hydrogen cyanide by ammoxidation of methanol, iron antimonate is present as a crystalline phase, and molybdenum, bismuth, iron, potassium, M component,
N component, silica is an essential component, and the product of valence and atomic ratio of molybdenum as molybdic acid 20 is a metal element capable of forming a metal molybdate other than iron antimonate, that is, bismuth, iron, potassium, M, N The reaction is carried out using a fluidized bed catalyst in which the number 20 / p divided by the sum p of the product of the valence of the T component element and the atomic ratio is 0.8 to 1, and while appropriately adding a molybdenum-containing material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a catalyst and a reaction method suitable for producing hydrogen cyanide by ammoxidation of methanol.

[0002]

2. Description of the Related Art With respect to the production of hydrogen cyanide by ammoxidation of methanol, various catalysts have been disclosed as suitable catalysts. For example, Japanese Patent Publication No. 37-134
No. 60 discloses an oxide catalyst containing tin and antimony,
JP-B-51-35400 discloses a composite oxide catalyst of molybdenum and many other elements.
No. 39 discloses an oxide catalyst containing metal elements such as iron, cobalt, and nickel and antimony.

[0003] Since then, the improvement of these catalysts has been energetically continued. For example, Japanese Patent Publication No. 61-4771, Japanese Patent Publication No. 63-16330, Japanese Patent Application Laid-Open No. 4-18051, and Japanese Patent Publication No. 7-64555. An improved patent such as a gazette is disclosed.

[0004]

Although these prior art catalysts were effective in improving the hydrogen cyanide yield to some extent, further improvements are required, especially for catalysts having a high molybdenum content. Even if the initial yield of hydrogen cyanide is good, it is still insufficient in terms of reproducibility in catalyst production, structural stability, stable reaction over a long period of time, and the like.

[0005] For this reason, there has been a demand for a catalyst which satisfies the requirements of obtaining a good hydrogen cyanide yield and being stable with time in the use of a reaction. The present invention has been made to solve these problems, and particularly relates to a catalyst having a high molybdenum content as a catalyst suitable for producing hydrogen cyanide by ammoxidation of methanol using a fluidized bed.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that iron, antimony, molybdenum, bismuth, iron, potassium, M component and N component are contained as essential components. The total sum of the products of the valences and atomic ratios of metal elements capable of forming metal molybdates other than iron antimonate, that is, bismuth, iron, potassium, M, N and T component elements, is molybdenum of molybdenum. To exhibit good performance by adjusting the product of the valence and the atomic ratio as a product to be in a specific range not less than the stoichiometric value, and to react while appropriately adding a molybdenum-containing material to this. It was found that its performance could be effectively maintained for a long time.

The catalyst composition provides a high yield of hydrogen cyanide and has a stable catalyst structure, so that it can withstand long-term reaction use. If the molybdenum component is greater than the stoichiometric value calculated above, the excess molybdenum component will enter the interface of the metal molybdate which should function as a catalyst, causing functional inhibition or an undesirable reaction with iron antimonate. Or occur. If the content of the molybdenum component is too small, the hydrogen cyanide yield decreases and the change with time increases.

However, if this catalyst continues to react,
A decrease in the yield of hydrogen cyanide, which is mainly due to the escape of the molybdenum component, is observed. The reaction temperature of the ammoxidation reaction exceeds 400 ° C., which is considered to be inevitable for such a catalyst having a high molybdenum content. By reacting while adding and replenishing molybdenum-containing materials, it was possible to maintain a high hydrogen cyanide yield for a long time. Since the catalyst of the present invention is structurally stable, and the addition of the molybdenum-containing material can sufficiently recover the reaction results, and can be applied repeatedly, the combination of this method makes it possible to use the reaction for a longer period of time. It has become possible.

The addition of the molybdenum-containing material may be performed at the beginning of the reaction. In general, the catalyst is used for the reaction after optimizing the surface composition of the catalyst according to the composition, preparation method, etc., but this is not always realized.
When the molybdenum-containing material is added first and reacted, the yield of the desired product may be increased. This is considered to be the result of optimization of the catalyst surface composition and structure including the addition of molybdenum-containing materials.

As described above, the conventional catalyst has an insufficient yield of hydrogen cyanide, and the recovery of the performance is insufficient even if a molybdenum-containing material is added when the yield is reduced due to long-term use. According to the present invention, there has been provided a method capable of maintaining a high hydrogen cyanide yield for a long period of time.

That is, the present invention provides a method for producing hydrogen cyanide, which comprises using a fluidized bed catalyst having a composition represented by the following empirical formula in producing hydrogen cyanide by ammoxidation of methanol, and a method for producing molybdenum. The present invention relates to a method for producing hydrogen cyanide, which comprises performing a reaction while adding a substance. (Fe Sba) b Mo10 B
ic Fed Kk Mm Nn Gg Qq Rr Tt Ox (SiO2) y (where, (Fe S
ba) indicates iron and antimony forming iron antimonate, Mo, Bi, Fe and K indicate molybdenum, bismuth, iron and potassium, respectively, and M indicates magnesium, calcium, strontium, barium, manganese, and cobalt. , Nickel, copper, at least one element selected from the group consisting of zinc and cadmium, N is chromium, yttrium, lanthanum, cerium, praseodymium, neodymium,
Samarium, aluminum, at least one element selected from the group consisting of gallium and indium, G is at least one element selected from the group consisting of ruthenium, rhodium, palladium, rhenium, osmium, iridium, platinum and silver, Q is Titanium, zirconium, vanadium, niobium, tantalum, tungsten, germanium, tin, at least one element selected from the group consisting of lead and antimony, R is at least one element selected from the group consisting of boron, phosphorus and tellurium, T is at least one element selected from the group consisting of lithium, sodium, rubidium, cesium and thallium, O is oxygen, Si is silicon, and subscripts a, b, c, d, k, m, n, g, q, r,
t, x and y indicate the atomic ratio, and when Mo = 10, a = 0.8 to 2, b = 0.
5-20, c = 0.1-2, d = 0.3-3, k = 0.05-2, m = 3-8, n = 0.
1 to 3, g = 0 to 0.5, q = 0 to 3, r = 0 to 3, t = 0 to 1, x = the number of oxygen in the metal oxide generated by combining the above components, y = 20 ~ 2
00. Further, the product 20 of the valence and the atomic ratio of molybdenum as molybdic acid is divided by the sum p of the product of the valence and the atomic ratio of bismuth, iron, potassium, M, N and T component elements.
p is 0.8 to 1. )

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. In the catalyst used in the present invention, iron antimonate is present as a crystalline phase, and molybdenum, bismuth, iron, potassium,
It is essential that M component, N component and silica are included,
Unless each component is within the above-mentioned composition range, the object of the present invention cannot be achieved. Iron antimonate is disclosed in
It is a compound represented by the chemical formula FeSbO4 described in JP-A-4-118051, JP-A-10-231125, and the like, and its presence can be confirmed by X-ray diffraction of the catalyst. Iron antimonate is essential for improving the yield of hydrogen cyanide and improving the physical properties of the catalyst.

Bismuth can exhibit good catalytic performance in a relatively small composition range. In general, if the amount of iron components other than iron antimonate is too large, the hydrogen cyanide yield will decrease. Conversely, if the amount is too small, the hydrogen cyanide selectivity at the initial stage of the reaction will increase, but the stability over time will deteriorate. The M component contributes to stabilization of the catalyst structure. M
As the components, magnesium, calcium, manganese, cobalt, nickel, zinc and the like are particularly preferable. N
Components are also effective in stabilizing the catalyst structure. As the N component, chromium, lanthanum, cerium, and the like, and preferably containing two of these elements, are more preferably used in combination with chromium and other elements. The T component contributes to the adjustment of the acidity of the catalyst together with the potassium component, and works to improve the selectivity of hydrogen cyanide and to suppress the generation of by-products. As the T component, particularly, rubidium and cesium are preferable.

As the catalyst component, G, Q and R
Ingredients can be added. These are added as needed for the purpose of stabilizing the catalyst structure, improving the oxidation-reduction properties, adjusting the acidity / basicity, and the like. As the G component, palladium, silver and the like are preferable, and as the Q component, zirconium, vanadium, niobium, tungsten, tin, antimony and the like are preferable. The R component is added in a small amount as necessary for the purpose of improving hydrogen cyanide selectivity and adjusting by-products.

[0015] The method of the present invention is carried out by a fluidized bed reaction. Therefore, the catalyst needs to have physical properties suitable for the fluidized bed reaction. For that purpose, silica is used as a carrier component.

What is important in the present invention is that the metal elements capable of forming the raw material iron antimonate and other metal molybdates, namely, bismuth, iron, potassium, M, N and T
When the component raw material and the molybdenum component raw material are mixed and prepared, bismuth, iron and the valence of the N component element are 3, the valence of the M component element is 2, the valence of potassium and the T component element are 1,
The product 20 of the valency of molybdenum as molybdic acid 2 and the atomic ratio 10 is 20 as a metal element capable of forming a metal molybdate other than iron antimonate, that is, bismuth, iron, potassium, M, N
And the number divided by the sum p of the products of the valences and atomic ratios of the T component elements
It is prepared by mixing, spray-drying, and firing in a range where 0 / p is 0.8 to 1.

Various methods for preparing iron antimonate have been proposed. For example, JP-A-4-118051,
There are methods described in, for example, Japanese Patent Application Laid-Open No. 10-231125. In the production of the catalyst of the present invention, it is important that iron antimonate is prepared in advance by these methods and then mixed with other catalyst component raw materials. This iron antimonate may contain a small amount of elements other than antimony and iron. The presence of iron antimonate contributes to improvement of hydrogen cyanide selectivity and improvement of physical properties as a fluidized bed catalyst.

This iron antimonate is mixed with the other component raw materials. In order to construct a preferable catalyst structure, particularly in a composition region where bismuth and iron are small as in the catalyst composition of the present invention, the above-mentioned 20 / It is important that the value of pe be between 0.8 and 1. The catalysts of this system consist of multiple phases, each of which must have an organic relationship. However, when the 20 / p value is smaller than 0.8, the metal element that is to be a counter ion of molybdic acid becomes an oxide without forming molybdate, and the selectivity of the target product in the catalytic reaction is reduced. Is likely to be impaired.
It was also found that it was difficult to establish a good relationship between the polyphases in a composition region larger than 1. It is considered that this was one of the causes of deterioration in reproducibility in the production of the catalyst in the conventional composition range. If this value is larger than 1, free molybdenum will enter between these phases as an oxide, and will become a hindrance factor of the catalyst function or cause an undesirable reaction with iron antimonate during catalyst preparation.

The method for preparing the catalyst of the present invention may be selected from the methods disclosed in the above-mentioned prior arts and applied. As a raw material of the molybdenum component, molybdenum oxide, ammonium paramolybdate, etc., as a raw material of the bismuth component, bismuth oxide, bismuth nitrate, bismuth carbonate, bismuth oxalate, etc., and as an iron component raw material, iron nitrate, iron oxalate, etc. However, potassium nitrate, potassium hydroxide and the like are used as potassium component raw materials, and respective oxides, hydroxides, nitrates and the like are used as M, N, G and T component raw materials. As the Q component raw materials, respective oxides, hydroxides, nitrates, oxyacids or salts thereof, and the like, as the R component raw materials, boric acid and boric anhydride for boron, and orthophosphoric acid for phosphorus, In the case of tellurium, metallic tellurium, tellurium dioxide,
Tellurium trioxide, telluric acid and the like are used. As the silica raw material, silica sol, fumed silica and the like are used, and it is convenient to use silica sol.

The iron antimonate is mixed with other component raw materials to prepare a slurry. The catalyst raw materials are mixed, the pH of the slurry is adjusted if necessary, and a heat treatment or the like is added to prepare a catalyst slurry. When the pH is adjusted to a relatively high value of 3 to 8, a chelating agent such as ethylenediaminetetraacetic acid, lactic acid, citric acid, tartaric acid, and gluconic acid is used according to the method described in Japanese Patent No. 2747920 to suppress gelation of the slurry. It is good to coexist. When producing by adjusting the pH to a relatively low value of 1 to 3, coexistence of a chelating agent is not always necessary, but good results may be obtained by adding a small amount in some cases.

The slurry thus prepared is spray-dried. As the spray drying device, a general device such as a rotating disk type or a nozzle type may be used. The conditions are adjusted so that a catalyst having a preferable particle size as a fluidized bed catalyst is obtained. After drying, 20
After firing at 0-500 ° C, 0.1-20 at 500-700 ° C
Bake for hours. The firing atmosphere is preferably an oxygen-containing gas. It is convenient to carry out in air, but it is also possible to use a mixture of oxygen and nitrogen, carbon dioxide gas, water vapor and the like. For firing, a box furnace, a tunnel furnace, a rotary furnace, a fluidized furnace, or the like is used. The particle size of the fluidized bed catalyst produced in this way is 5 to 2
The thickness is preferably set to 00 μm.

When a molybdenum-containing fluidized bed catalyst is used for the production of hydrogen cyanide, there is known a method for maintaining the yield of the desired product by adding a molybdenum-containing material during the reaction as described above. However, the effect cannot be expected sufficiently unless it is applied to a catalyst having a stable catalyst structure. The catalyst of the present invention performs this type of reaction.
Even if the reaction is carried out at a temperature exceeding 0 ° C. for a long period of time, it is structurally stable. Therefore, by adding a molybdenum-containing material, the reaction can be continued while maintaining a reaction result equal to or higher than the initial one. Even with such a structurally stable catalyst, the molybdenum component volatilizes slowly from the catalyst under the reaction conditions, possibly causing damage to the catalyst structure, and the molybdenum-containing material is added before this becomes crucial. Need to be done.

Examples of the molybdenum-containing material used here include molybdenum metal, molybdenum trioxide, molybdic acid, ammonium dimolybdate, ammonium paramolybdate, ammonium octamolybdate, ammonium dodecamolybdate, and phosphomolybdate. . Further, these molybdenum-containing substances may be used by being supported on an inert substance or a catalyst. Although it can be used as a gas or a liquid, it is practical to use these solid molybdenum components as a powder. In particular, a method of using a molybdenum component enriched in a catalyst is effective. This method is a preferred mode of use, in that the added molybdenum is used efficiently and troubles due to deposition of molybdenum oxide in the system are suppressed. The manufacturing method of molybdenum-rich catalyst
The method described in JP-A-2-56939 or JP-A-11-33400 can be applied.

These molybdenum contents are added to the reactor from time to time, either continuously or intermittently. The timing and amount of addition may be appropriately determined according to the course of the reaction, but the amount added at one time is preferably in the range of 0.05 to 2% by weight of molybdenum with respect to the charged catalyst. Even if a large amount is added at one time, it escapes out of the reaction system unnecessarily and is wasted.
Care must be taken as it may cause operational problems due to deposition in the reactor and adhesion to the heat exchanger.

In the ammoxidation of methanol, methanol / ammonia / oxygen is usually 1 / 0.9 to 1.3 / 0.8 to 10 (molar ratio).
The reaction is performed at a reaction temperature of 370 to 500 ° C. and a reaction pressure of normal pressure to 500 kPa using a supply gas having a composition range of Apparent contact time is 0.1-20
Seconds. As the oxygen source, it is convenient to use air, which may be diluted with steam, carbon dioxide, saturated hydrocarbon, or the like, or may be used after being enriched with oxygen.

[0026]

The present invention will be described below in more detail with reference to examples and comparative examples.

Activity test of the catalyst Hydrogen cyanide was synthesized by ammoxidation of methanol to evaluate the activity of the catalyst. The inner diameter of the catalyst flow section is 25 mm,
A 400 mm high fluidized bed reactor is filled with a catalyst, and a mixed gas of methanol / ammonia / air = 1 / 1.2 / 9.5 (2.0 as oxygen) (molar ratio) with a gas linear velocity of 4.5 cm / sec.
Sent by The reaction pressure was 100 kPa. Note that a molybdenum component was appropriately added during the reaction. With respect to the molybdenum component, 0.1 to 0.2% by weight of molybdenum was added at intervals of 50 to 150 hours to the charged catalyst using several molybdenum compounds and a catalyst enriched in the molybdenum component.

The contact time and hydrogen cyanide yield in Examples and Comparative Examples are defined by the following equations. Contact time (sec) = catalyst volume based on apparent bulk density (ml) /
Supply gas flow rate converted to reaction conditions (ml / sec) Hydrogen cyanide yield (%) = moles of hydrogen cyanide generated / moles of supplied methanol × 100

Example 1 The composition was Fe_ThreeSb_3.3 Mo_Ten Bi_0.4 Fe_1.3K_0.2Ni₆ Cr_0.8
Ce_0.1P_0.2B_0.2O_x (SiO_Two)₃₅(The atomic ratio x of oxygen is
Since the value is naturally determined by the valence of the element,
The description of the prime is omitted. ) Is prepared as follows
did. Ammonium paramolybdate in 3000 g of pure water 346.
Dissolve 9 g, then add 4.5 g of 85% phosphoric acid and 2.4 g of boric acid
Add. To this liquid 3.3% nitric acid 270 g bismuth nitrate 57.2
g, potassium nitrate 4.0 g, nickel nitrate 342.8 g,
62.5 g, cerium nitrate 8.5 g, and citric acid 25.0 g
The liquid was mixed. Add 104.2 g of iron nitrate to 270 g of pure water
A solution in which 25.0 g of acid was dissolved was added. Then 20% silica sol 20
65.8g was added. While stirring this slurry, 15% ammonia
Water was added to adjust the pH to 2. Add this at 98 ° C for 1.5 hours.
Heat treated. In addition, separately prepared 20% iron antimonate
733.8g of rally was added. Slurry prepared in this way
The rotating disk type spray dryer has an inlet temperature of 330 ° C and an outlet temperature of 1
Spray dried at 60 ° C. 2 hours at 250 ℃
Heat treatment at 400 ° C for 2 hours, and finally fluidized firing at 660 ° C for 3 hours
Done.

The iron antimonate slurry used here was prepared as follows. 1110.1 g of nitric acid (65% by weight) and 615.3 g of pure water are mixed, and 133.3 g of electrolytic iron powder is added little by little. After the iron powder was completely dissolved, 384.7 g of antimony trioxide powder was mixed, and 10% ammonia water was added dropwise with stirring to adjust the pH to 1.8. While stirring this slurry 9
Heated at 8 ° C for 3 hours. The slurry was dried by a spray drier at an inlet temperature of 330 ° C. and an outlet temperature of 160 ° C., and calcined at 250 ° C. for 2 hours and 400 ° C. for 2 hours. 850 ° C in a nitrogen stream 3
Fired for hours. After firing, the mixture was ground and mixed with pure water to obtain a 20% iron antimonate slurry. The iron antimonate slurry thus prepared was used in the following Examples and Comparative Examples.

Example 2 The composition was Fe ₃ Sb _3.3 Mo ₁₀ Bi _0.4 Fe _1.1 K _0.3 Ni ₄ Co ₂ Cr
The _0.8 Ce _0.5 P _0.2 catalyst is (SiO _{2) 3 5} were prepared in the same manner as in Example 1 was fired under the conditions shown in Table 1. However, nitrate was used as the Co raw material.

Example 3 Composition of Fe_Three Sb_3.3 Mo_Ten Bi_0.4 Fe_1.3 K_0.2Ni_5.5 Zn_0.2 
Cr_1.5 Ce_0.6La_0.2 Ge _0.2B_0.2 (SiO_Two)₃₅Is a catalyst
Prepared in the same manner as in Example 1 and fired under the conditions shown in Table 1.
did. However, nitrates were used as La, Zn, and Ge raw materials.

Example 4 The composition was Fe ₃ Sb _3.3 Mo ₁₀ Bi _0.3 Fe _1.5 K _0.2 Ni ₅ Mg ₁ Cr
_A catalyst of _0.5 Ce _0.3 Pr _0.2 (SiO ₂ ) ₃₅ was prepared in the same manner as in Example 1, and calcined under the conditions shown in Table 1. Where P
r, Mg raw materials used nitrate.

Example 5 The composition was Fe ₃ Sb _3.3 Mo ₁₀ Bi _0.5 Fe _1.3 K _0.1 Ni _5.75 Mn _0.5
A catalyst that was Cr _0.8 Ce _0.75 Pd _0.01 Rb _0.1 P _0.1 B _0.1 (SiO ₂ ) ₄₀ was prepared as follows. Dissolve 321.1 g of ammonium paramolybdate in 3000 g of pure water, then add 85% phosphoric acid
2.1 g and 1.1 g of boric acid are added. Bismuth nitrate 44.1 g, potassium nitrate 1.8 g, nickel nitrate 30
4.1 g, manganese nitrate 26.1 g, chromium nitrate 58.2 g, cerium nitrate 59.2 g, palladium nitrate 0.4 g, rubidium nitrate 2.7
g and a solution in which 25 g of citric acid were dissolved. Then 20%
2185.6 g of silica sol was added, and 15% aqueous ammonia was added dropwise with stirring to adjust the pH to 7.7. This was heat-treated at 98 ° C. for 1.5 hours. Add 95.5 g of iron nitrate and 2 citric acid to 270 g of pure water
A solution in which 5 g was dissolved was added, and 679.3 g of a separately prepared 20% iron antimonate slurry was added.

The slurry thus prepared was spray-dried with a rotating disk type spray dryer at an inlet temperature of 330 ° C. and an outlet temperature of 160 ° C. The dried particles were heat-treated at 250 ° C. for 2 hours and 400 ° C. for 2 hours, and finally subjected to fluid firing at 670 ° C. for 3 hours.

Example 6 When the composition was Fe_ThreeSb_3.3 Mo_Ten Bi_0.8 Fe_1.3K_0.2 Ni_5.5Cr
_0.8Ce_0.4In_0.2W_0.5P _0.2(SiO_Two)₆₀The catalyst that is
It was prepared as described above. Paratungstic acid in 3000 g of pure water
Dissolve 19.2 g of ammonium and then paramolybdic acid
Mix and dissolve 260 g of ammonium, and add 3.4 g of 85% phosphoric acid
added. To this solution 57.2 g of bismuth nitrate in 270 g of 3.3% nitric acid,
3.0 g of potassium nitrate, 235.5 g of nickel nitrate, chromium nitrate 4
7.1 g, cerium nitrate 25.6 g, indium nitrate 3.5 g, que
A solution in which 25 g of acid was dissolved was mixed. Then 20% silica sol
2655.1 g were mixed. While stirring this slurry,
Monia water was added dropwise to adjust the pH to 5. 98 ° C under reflux
Heat treatment was performed for 1.5 hours. Add 77.4g of iron nitrate to 270g of pure water
Add a solution prepared by dissolving 25 g of citric acid, and add
550 g of the prepared 20% iron antimonate slurry was added.

The slurry thus prepared was spray-dried with a rotating disk type spray dryer under the conditions of an inlet temperature of 330 ° C. and an outlet temperature of 160 ° C. The dried particles are dried at 250 ° C for 2 hours,
Heat treatment was performed for 670 ° C. for 3 hours.

Example 7 The composition was Fe ₃ Sb _3.3 Mo ₁₀ Bi _0.5 Fe ₂ K _0.2 Ni ₄ Mg _1.5 Cr
_A catalyst of _0.5 Ce _0.5 Al _0.1 Nb _0.1 (SiO ₂ ) ₃₅ was prepared in the same manner as in Example 6, and calcined under the conditions shown in Table 1. However, nitrate was used for the Al and Mg raw materials, and niobium hydrogen oxalate was used for the Nb raw material.

Example 8 The composition was Fe _1.5 Sb _1.7 Mo ₁₀ Bi _0.5 Fe ₁ K _0.2 Ni ₄ Co _1.5 Cr
_A catalyst of ₂ Ce _0.5 Ru _0.05 Cs _{0.0 5} P _0.3 (SiO ₂ ) ₃₅ was prepared in the same manner as in Example 6, and calcined under the conditions shown in Table 1. However, nitrates were used as Co, Ru, and Cs raw materials.

Example 9 The composition was Fe_Five Sb_5.5Mo_Ten Bi_0.5 Fe_1.3 K_0.2 Ni₆Cr₁ Ce
_0.2 Zr_0.2 P_0.1(SiO_Two) ₃₅Is the same as in Example 6.
And calcined under the conditions shown in Table 1. However, Zr
 The raw material used was zirconium oxynitrate.

Example 10 The composition was Fe ₇ Sb _7.7 Mo ₁₀ Bi _0.5 Fe _1.2 K _0.2 Ni _5.75 Cr _1.5
A catalyst of Ce _0.5 Sm _0.1 Nd _0.1 V _0.1 Te _0.25 (SiO ₂ ) ₃₅ was prepared in the same manner as in Example 6, and calcined under the conditions shown in Table 1. However, nitrates were used for Sm and Nd raw materials, ammonium metavanadate was used for V raw materials, and telluric acid was used for Te raw materials.

Comparative Example 1 Composition of Fe_ThreeSb_3.3 Mo_Ten Bi_0.4 Fe_0.6K_0.2Ni₆ Cr_0.8 Ce
_0.4P_0.2 B_0.2 (SiO_Two) ₃₅Is the same as in Example 1.
It was prepared by the method and calcined under the conditions shown in Table 1.

Comparative Example 2 The composition was Fe ₃ Sb _3.3 Mo ₁₀ Bi _0.4 Fe _1.1 K _0.2 Ni ₆ P _0.2 B
_A catalyst of _0.2 (SiO ₂ ) ₃₅ was prepared in the same manner as in Example 1 and calcined under the conditions shown in Table 1.

Comparative Example 3 Composition of Fe_Three Sb_3.3 Mo_TenBi_1.2 Fe_1.3 K_0.2 Ni_5.5 Zn_0.2
Cr_1.5 Ce_0.6La_0.2Ge _0.2B_0.2 (SiO_Two)₃₅Is a catalyst
Prepared in the same manner as in Example 6 and calcined under the conditions in Table 1.
did.

Comparative Example 4 The composition was Fe ₃ Sb _3.3 Mo ₁₀ Bi _0.4 Fe ₂ K _0.2 Ni ₆ Zn _0.2 Cr
_A catalyst of _1.5 Ce _0.6 La _0.2 Ge _0.2 B _0.2 (SiO ₂ ) ₃₅ was prepared in the same manner as in Example 6, and calcined under the conditions shown in Table 1.

The molybdenum-enriched catalysts used in Examples 7 to 10 and Comparative Examples 3 to 4 were prepared by impregnating each of the catalysts with an aqueous solution of ammonium paramolybdate, followed by drying and calcining. .

Using the catalysts of these Examples and Comparative Examples,
Under the above reaction conditions, an ammoxidation reaction of methanol was performed. The results are shown in the table below.

[0048]

[Table 1]

[0049]

According to the process for producing hydrogen cyanide of the present invention, a high yield of hydrogen cyanide is obtained, and the stability of the reaction is improved because the catalyst structure is stable. The catalyst performance can be maintained.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) C01B 33/20 C01B 33/20 // B01J 8/24 B01J 8/24 F term (Reference) 4G069 AA02 AA08 BB06A BB06B BC02A BC03A BC03B BC04A BC05A BC05B BC06A BC06B BC09A BC10A BC10B BC12A BC13A BC16A BC16B BC17A BC18A BC18B BC19A BC21A BC22A BC23A BC23B BC25A BC25B BC26A BC26B BC32A BC35A BC35B BC36A BC40A BC42A BC42B BC43A BC43B BC44A BC44B BC50A BC51A BC51B BC54A BC54B BC55A BC55B BC56A BC58A BC58B BC59A BC59B BC60A BC60B BC62A BC62B BC64A BC66A BC66B BC67A BC67B BC68A BC68B BC70A BC70B BC71A BC72A BC72B BC73A BC74A BC75A BD03A BD03B BD05A BD05B BD07A BD07B BD10A BD10B CB53 DA08 EB18Y FB57 4BA07 BA17 BA12 BA17 BA12 BA17 BA12 BA17 BA12 BA26 BA28 BA29 BA30 BA32 BA33 BA34 BA36 BA37 BA38 BA40 BA41 BA42 BA44 BA45 BA46 BA48 BA49 BA52 BA53 BA56 BA57 BA58 BA59 BA60 BA64 BA65 BA66 BA70 BA72 BA73 BD20 CF01 FB11 FE04 GA01 UA01 U B38

Claims (3)

[Claims] 1. A method for producing hydrogen cyanide, comprising using a fluidized bed catalyst having a composition represented by the following empirical formula when producing hydrogen cyanide by ammoxidation of methanol. (Fe Sba) b Mo10 Bic Fed Kk Mm Nn Gg Qq Rr Tt Ox (Si
O2) y (wherein (Fe Sba) represents iron and antimony forming iron antimonate, Mo, Bi, Fe and K represent molybdenum, bismuth, iron and potassium, respectively, M is magnesium, At least one element selected from the group consisting of calcium, strontium, barium, manganese, cobalt, nickel, copper, zinc and cadmium; N is chromium, yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, aluminum, gallium and indium At least one element selected from the group consisting of, G is at least one element selected from the group consisting of ruthenium, rhodium, palladium, rhenium, osmium, iridium, platinum and silver, and Q is titanium, zirconium, vanadium, niobium , Tantalum, tungsten, germanium, tin, lead and aluminum R is at least one element selected from the group consisting of boron, phosphorus and tellurium; T is at least one element selected from the group consisting of
Is at least one element selected from the group consisting of lithium, sodium, rubidium, cesium and thallium,
O is oxygen, Si is silicon, and subscripts a, b, c, d, k, m,
n, g, q, r, t, x and y indicate the atomic ratio, and when Mo = 10, a =
0.8-2, b = 0.5-20, c = 0.1-2, d = 0.3-3, k = 0.05-2,
m = 3 ~ 8, n = 0.1 ~ 3, g = 0 ~ 0.5, q = 0 ~ 3, r = 0 ~ 3, t = 0 ~
1, x = the number of oxygen of the metal oxide generated by combining the above components, and y = 20 to 200. Further, the product 20 of the valence and atomic ratio of molybdenum as molybdic acid is calculated by summing the product of the valence and the atomic ratio of bismuth, iron, potassium, M, N and T component elements p
The number 20 / p divided by 0.8 is 0.8 to 1. ) 2. The method for producing hydrogen cyanide according to claim 1, wherein the reaction is carried out while adding a molybdenum-containing substance. 3. The method for producing hydrogen cyanide according to claim 2, wherein the molybdenum-containing substance to be added is a molybdenum-enriched catalyst.