JP3872270B2 - Production method of hydrogen cyanide - Google Patents

Description

【００４９】
【発明の効果】
本発明のシアン化水素の製法は、高いシアン化水素収率を与えると共に、触媒構造が安定なものであるため、反応の経時安定性が向上し、モリブデン成分を補給添加する事により長期にわたり触媒性能維持が可能である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a catalyst and a reaction method suitable for producing hydrogen cyanide by ammoxidation of methanol.
[0002]
[Prior art]
Regarding the production of hydrogen cyanide by ammoxidation of methanol, various catalysts have been disclosed as suitable catalysts. For example, Japanese Patent Publication No. 37-13460 discloses an oxide catalyst containing tin and antimony, Japanese Patent Publication No. 51-35400 discloses a composite oxide catalyst of molybdenum and many other elements, and Japanese Patent Publication No. 54-39839. The publication discloses an oxide catalyst containing metal elements such as iron, cobalt, nickel and antimony.
[0003]
Thereafter, the improvement of these catalysts continued vigorously. For example, JP-B-61-4771, JP-B-63-16330, JP-A-4-118051, JP-B-7-64555, etc. Improved patents are disclosed.
[0004]
[Problems to be solved by the invention]
Although these prior art catalysts were effective in improving the hydrogen cyanide yield as such, further improvements have been demanded, particularly for catalysts with a high molybdenum content, the initial yield of hydrogen cyanide was good. However, it is still insufficient in terms of reproducibility in catalyst production, structural stability, or a stable reaction over a long period of time.
[0005]
For this reason, there has been a demand for a catalyst that can provide a good hydrogen cyanide yield and satisfy the requirements of being stable over time when used in a reaction. The present invention is intended to solve these problems. In particular, a catalyst having a high molybdenum content is improved as a catalyst suitable for producing hydrogen cyanide by ammoxidation reaction of methanol using a fluidized bed.
[0006]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventors have found that a catalyst containing iron antimonate, molybdenum, bismuth, iron, potassium, M component and N component as essential components other than iron antimonate. The sum of the products of the valence and atomic ratio of each of the metal elements capable of forming a metal molybdate, ie, bismuth, iron, potassium, M, N, and T, is the valence and atomic ratio of molybdenum as molybdic acid. By developing the product to have a specific range of more than the stoichiometric value, the product will exhibit good performance. I found that I could maintain it.
[0007]
This catalyst composition gives a high hydrogen cyanide yield and is stable as a catalyst structure, so that it can withstand long-term reaction use. When the molybdenum component is larger than the stoichiometric value calculated above, the excess molybdenum component enters the interface of the metal molybdate that should function as a catalyst, causing functional inhibition or an undesirable reaction with iron antimonate. May occur. On the other hand, when the content of the molybdenum component is too small, the yield of hydrogen cyanide decreases and the change with time increases.
[0008]
However, when this catalyst continues to react, a decrease in the yield of hydrogen cyanide, which is thought to be mainly due to the escape of the molybdenum component, is observed. The reaction temperature of the ammoxidation reaction exceeds 400 ° C., and this type of catalyst with a high molybdenum content is considered to be unavoidable. It was possible to maintain a high hydrogen cyanide yield for a long period of time by reacting while adding and replenishing molybdenum-containing material. The catalyst of the present invention is structurally stable, and the recovery of the reaction results is sufficiently achieved by the addition of the molybdenum-containing material, and this can be repeatedly applied. It has become possible.
[0009]
The addition of the molybdenum-containing material may be performed at the initial stage of the reaction. The catalyst is generally used for the reaction by optimizing the composition of the catalyst surface depending on the composition, preparation method, etc., but this is not always realized. When the molybdenum-containing material is first added and reacted, the target product yield may be increased. This is considered to be the result of optimization of the catalyst surface composition and structure including addition of molybdenum-containing material.
[0010]
As described above, the conventional catalyst has an insufficient hydrogen cyanide yield, and when the yield is lowered by long-term use, the performance recovery is insufficient even when a molybdenum-containing material is added. Provided a method capable of maintaining a high hydrogen cyanide yield over a long period of time.
[0011]
That is, in the present invention, when producing hydrogen cyanide by ammoxidation of methanol, a fluidized bed catalyst having a composition represented by the following empirical formula is used, and a molybdenum-containing material is used for the production. The present invention relates to a method for producing hydrogen cyanide, characterized in that the reaction is carried out while adding. (Fe Sba) b Mo10 Bic Fed Kk Mm Nn Gg Qq Rr Tt Ox (SiO2) y
(Wherein (Fe Sba) represents iron and antimony forming iron antimonate, Mo, Bi, Fe and K represent molybdenum, bismuth, iron and potassium, respectively, M represents magnesium, calcium and strontium And at least one element selected from the group consisting of barium, manganese, cobalt, nickel, zinc and cadmium, N is selected from the group consisting of chromium, lanthanum, cerium, praseodymium, neodymium, samarium, aluminum, gallium and indium At least one element, G is at least one element selected from the group consisting of ruthenium and palladium, Q is at least one selected from the group consisting of titanium, zirconium, vanadium, niobium, tantalum, tungsten, germanium, tin and lead Element R, from the group consisting of boron, phosphorus and tellurium At least one element selected, T is at least one element selected from the group consisting of lithium, sodium, rubidium and cesium, O is oxygen, Si is silicon, and the subscripts a, b, c, d, k, m , N, g, q, r, t, x and y represent atomic ratios, and when Mo = 10, a = 0.8-2, b = 0.5-20, c = 0.1-2, d = 0.3-3, k = 0.05 to 2, m = 3 to 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 above components are combined The number of oxygen in the metal oxide produced is y = 20 to 200. Furthermore, the product 20 of the valence and the atomic ratio of molybdenum as molybdic acid is expressed by bismuth, iron, potassium, M, N and T component elements. The number 20 / p divided by the sum p of the product of the valence and atomic ratio is 0.8-1.
[0012]
DETAILED DESCRIPTION OF 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 it is essential that molybdenum, bismuth, iron, potassium, M component, N component and silica are included, and each component is within the above composition range. Otherwise, the object of the present invention cannot be achieved. Iron antimonate is a compound represented by the chemical formula of FeSbO4 described in JP-A-4-18051, JP-A-10-231125, etc., 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.
[0013]
Bismuth can exhibit good catalytic performance in a relatively small composition region. In general, when the amount of iron components other than iron antimonate contained is too large, the yield of hydrogen cyanide is lowered. On the other hand, when the amount is too small, the hydrogen cyanide selectivity at the initial stage of the reaction is increased, but the temporal stability is deteriorated. M component contributes to the stabilization of the catalyst structure. As the M component, magnesium, calcium, manganese, cobalt, nickel, zinc and the like are particularly preferable. N component is also effective in stabilizing the catalyst structure. As the N component, chromium, lanthanum, cerium, and the like are preferably included, and two of these elements are preferably included, and it is more preferable to use chromium and another element in combination. The T component contributes to the adjustment of the acidity of the catalyst together with the potassium component, and works to improve the hydrogen cyanide selectivity and suppress the production of by-products. As the T component, rubidium and cesium are particularly preferable.
[0014]
As the catalyst component, the aforementioned G, Q and R components can be further added. These are added as necessary for the purpose of stabilizing the catalyst structure, improving redox characteristics, adjusting acid and 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 a fluidized bed reaction. For that purpose, silica is used as a carrier component.
[0016]
What is important in the present invention is that raw material iron antimonate and other metal elements capable of producing metal molybdate, that is, bismuth, iron, potassium, M, N and T component raw materials and molybdenum component raw materials are mixed. When preparing, the valence of bismuth, iron and N component element is 3, the valence of M component element is 2, the valence of potassium and T component element is 1, and the valence is 2 as molybdenum molybdate. The product 20 of atomic ratio 10 is the sum p of products of valence and atomic ratio of metal elements that can form metal molybdates other than iron antimonate, that is, bismuth, iron, potassium, M, N and T component elements. It is prepared by mixing, spray-drying, and baking within a range where the divided number 20 / p is 0.8 to 1.
[0017]
Various methods for preparing iron antimonate have been proposed. For example, there are methods described in JP-A-4-18051, JP-A-10-231125, etc., and these methods may be selected and used. 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 improved hydrogen cyanide selectivity and improved physical properties as a fluidized bed catalyst.
[0018]
This iron antimonate is mixed with the other component raw materials, but in order to construct a preferable catalyst structure, particularly in a composition region with a small amount of bismuth and iron like the catalyst composition of the present invention, the above value of 20 / pe is used. It is important to set 0.8 to 1. This family of catalysts consists of multiple phases, and each must have an organic relationship. However, when the 20 / p value is less than 0.8, the metal element that should be the counter ion of molybdic acid becomes an oxide or the like without forming molybdate, and the selectivity of the target product in the catalytic reaction It is easy to damage. In addition, it was found that it is difficult to establish a good relationship between the polyphases in a composition region larger than 1. This is considered to be one of the causes of deterioration in reproducibility in the production of the catalyst in the conventional composition region. When this value is larger than 1, free molybdenum enters between these phases as an oxide, which may inhibit the catalytic function or cause an undesirable reaction with iron antimonate during catalyst preparation.
[0019]
The method for preparing the catalyst of the present invention may be selected and applied from the methods disclosed in the above prior art. Molybdenum component materials include molybdenum oxide, ammonium paramolybdate, etc., bismuth component materials include bismuth oxide, bismuth nitrate, bismuth carbonate, bismuth oxalate, etc., and iron component materials include iron nitrate, iron oxalate, etc. However, potassium nitrate, potassium hydroxide and the like are used as the potassium component raw material, and respective oxides, hydroxides, nitrates and the like are used as the M, N, G and T component raw materials. Q component raw materials include respective oxides, hydroxides, nitrates, oxygen acids or salts thereof, and R component raw materials include boric acid and boric anhydride in the case of boron, orthophosphoric acid and the like in the case of phosphorus, In the case of tellurium, metal tellurium, tellurium dioxide, tellurium trioxide, telluric acid and the like are used. As the silica raw material, silica sol, fumed silica or the like is used, but it is convenient to use silica sol.
[0020]
Iron antimonate is mixed with other ingredients to prepare a slurry. The catalyst raw materials are mixed, the pH of the slurry is adjusted as necessary, and heat treatment is added to prepare a catalyst slurry. When manufacturing by adjusting the pH to 3-8, which is relatively high, a chelating agent such as ethylenediaminetetraacetic acid, lactic acid, citric acid, tartaric acid, gluconic acid is used in accordance with the method described in Japanese Patent No. 2747920 to suppress gelation of the slurry. Etc. should coexist. When manufacturing by adjusting the pH to 1 to 3 which is relatively low, the coexistence of a chelating agent is not necessarily required, but good results may be obtained by adding a small amount.
[0021]
The slurry thus prepared is spray dried. The spray drying device may be a general device such as a rotary disk type or a nozzle type. The conditions are adjusted so that a catalyst having a preferable particle size as a fluidized bed catalyst can be obtained. After drying, it is fired at 200 to 500 ° C., and further fired at 500 to 700 ° C. for 0.1 to 20 hours. The firing atmosphere is preferably an oxygen-containing gas. Although it is convenient to carry out in air, a mixture of oxygen and nitrogen, carbon dioxide, water vapor or the like can also be used. A box furnace, tunnel furnace, rotary furnace, fluidized furnace, or the like is used for firing. The particle size of the fluidized bed catalyst thus produced is preferably 5 to 200 μm.
[0022]
When using a molybdenum-containing fluidized bed catalyst for the production of hydrogen cyanide, a method for maintaining the yield of the target product by adding a molybdenum-containing material during the reaction as described above is known. However, unless it is applied to a catalyst having a stable catalyst structure, the effect cannot be sufficiently expected. The catalyst of the present invention is structurally stable even when used for a long period of time at a temperature exceeding 400 ° C. at which this kind of reaction is carried out. The reaction can be continued while maintaining Even with such a structurally stable catalyst, the molybdenum component gradually evaporates from the catalyst under the reaction conditions, and it is likely that the catalyst structure will be damaged, and the molybdenum content is added before this becomes critical. It becomes necessary to do.
[0023]
Examples of the molybdenum-containing material used here include metal molybdenum, molybdenum trioxide, molybdic acid, ammonium dimolybdate, ammonium paramolybdate, ammonium octamolybdate, ammonium dodecamolybdate, and phosphomolybdic acid. Further, these molybdenum-containing materials may be used by being supported on an inert substance or a catalyst. Although it can be used in the form of gas or liquid, it is practical to use these solid molybdenum components as powder. In particular, a method using a molybdenum component enriched in a catalyst is effective. This method is a preferred mode of use because the use efficiency of the added molybdenum is good and troubles due to precipitation of molybdenum oxide in the system are suppressed. The method described in Japanese Patent Publication No. 2-56939 or Japanese Patent Application Laid-Open No. 11-33400 can be applied to the production method of the molybdenum-enriched catalyst.
[0024]
These molybdenum-containing materials are added to the reactor continuously or intermittently from time to time. The addition timing and addition amount may be appropriately determined depending on the transition of the reaction, but the addition amount at a time is preferably in the range of 0.05 to 2% by weight as molybdenum with respect to the packed catalyst. Even if a large amount is added at a time, it will escape to the outside of the reaction system and will be consumed wastefully, and will be deposited and deposited in the reactor, or will adhere to the heat exchanger and cause operational problems. So be careful.
[0025]
Ammoxidation of methanol is usually performed using a feed gas having a composition range of methanol / ammonia / oxygen of 1 / 0.9 to 1.3 / 0.8 to 10 (molar ratio) at a reaction temperature of 370 to 500 ° C. and a reaction pressure of normal pressure to 500 kPa. Do. Apparent contact time is 0.1-20 seconds. As the oxygen source, it is convenient to use air, but this may be diluted with water vapor, carbon dioxide gas, saturated hydrocarbon or the like, or may be enriched with oxygen.
[0026]
【Example】
Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.
[0027]
Catalyst activity test Hydrogen cyanide by ammoxidation of methanol was synthesized to evaluate the activity of the catalyst.
The catalyst is packed in a fluidized bed reactor with an inner diameter of 25 mm and a height of 400 mm, and a mixed gas of methanol / ammonia / air = 1 / 1.2 / 9.5 (2.0 as oxygen) (molar ratio) is gas line. It was sent at a speed of 4.5 cm / sec. The reaction pressure was 100 kPa.
In addition, the molybdenum component was added suitably at the time of reaction. As for the molybdenum component, 0.1 to 0.2% by weight of molybdenum was added at intervals of 50 to 150 hours with respect to the packed catalyst using several molybdenum compounds and a catalyst enriched with the molybdenum component.
[0028]
The contact time and hydrogen cyanide yield in the 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 (%) = number of moles of hydrogen cyanide produced / number of moles of methanol supplied × 100
[0029]
Example 1
_{Composition, Fe 3 Sb 3.3 Mo 10 Bi} 0.4 Fe 1.3 K 0.2 Ni 6 Cr 0.8 Ce 0. 1 P _0.2 B _0.2 O _x A catalyst of (SiO ₂ ) ₃₅ (the oxygen atomic ratio x is a value naturally determined by the valence of other elements, so the description of oxygen is omitted hereinafter) was prepared as follows.
Dissolve 346.9 g of ammonium paramolybdate in 3000 g of pure water, then add 4.5 g of 85% phosphoric acid and 2.4 g of boric acid. A solution prepared by dissolving 57.2 g of bismuth nitrate, 4.0 g of potassium nitrate, 342.8 g of nickel nitrate, 62.5 g of chromium nitrate, 8.5 g of cerium nitrate, and 25.0 g of citric acid was mixed with 270 g of 3.3% nitric acid. To this was added a solution prepared by dissolving 104.2 g of iron nitrate and 25.0 g of citric acid in 270 g of pure water. Next, 2065.8 g of 20% silica sol was added. While stirring the slurry, 15% aqueous ammonia was added to adjust the pH to 2. This was heat-treated at 98 ° C. for 1.5 hours. Further, 733.8 g of 20% iron antimonate slurry prepared separately was added. The slurry thus prepared was spray-dried with a rotary disk 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 fluidized and fired at 660 ° C. for 3 hours.
[0030]
In addition, the iron antimonate slurry used here was prepared as follows.
Nitric acid (65 wt%) 1110.1g and pure water 615.3g are mixed, and electrolytic iron powder 133.3g is added little by little. After the iron powder was completely dissolved, 384.7 g of antimony trioxide powder was mixed, and 10% aqueous ammonia was added dropwise with stirring to adjust the pH to 1.8. The slurry was heated at 98 ° C. for 3 hours with stirring. The slurry was dried with a spray dryer at an inlet temperature of 330 ° C. and an outlet temperature of 160 ° C., and then calcined at 250 ° C. for 2 hours and at 400 ° C. for 2 hours. Further, it was calcined at 850 ° C. for 3 hours in a nitrogen stream. After firing, it was pulverized and mixed with pure water to obtain a 20% iron antimonate slurry. In the following examples and comparative examples, the iron antimonate slurry thus prepared was used.
[0031]
Example 2
Composition was prepared by the same method as _{Fe 3 Sb 3.3 Mo 10 Bi 0.4} Fe 1.1 K 0.3 Ni 4 Co 2 Cr 0.8 Ce 0.5 P 0.2 Catalyst Example 1 is a (SiO _{2) 35,} fired under the conditions shown in Table 1 did. However, nitrate was used as the Co raw material.
[0032]
Example 3
A catalyst having a composition of Fe ₃ Sb _3.3 Mo ₁₀ Bi _0.4 Fe _1.3 K _0.2 Ni _5.5 Zn _0.2 Cr _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 1, and Table 1 It baked on the conditions of this. However, nitrates were used as raw materials for La, Zn and Ge.
[0033]
Example 4
Composition is Fe ₃ Sb _3.3 Mo ₁₀ Bi _0.3 Fe _1.5 K _0.2 Ni ₅ Mg ₁ Cr _0.5 Ce _0.3 Pr _0.2 A catalyst of (SiO ₂ ) ₃₅ was prepared in the same manner as in Example 1, and calcined under the conditions shown in Table 1. However, nitrates were used as raw materials for Pr and Mg.
[0034]
Example 5
A catalyst having a composition of Fe ₃ Sb _3.3 Mo ₁₀ Bi _0.5 Fe _1.3 K _0.1 Ni _5.75 Mn _0.5 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 2.1 g of 85% phosphoric acid and 1.1 g of boric acid. This solution and 3.3% nitric acid 270g, bismuth nitrate 44.1g, potassium nitrate 1.8g, nickel nitrate 304.1g, manganese nitrate 26.1g, chromium nitrate 58.2g, cerium nitrate 59.2g, palladium nitrate 0.4g, rubidium nitrate 2.7g, citric acid 25g Was mixed with the solution. Next, 2185.6 g of 20% 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. To this was added a solution prepared by dissolving 95.5 g of iron nitrate and 25 g of citric acid in 270 g of pure water, and 679.3 g of 20% iron antimonate slurry prepared separately was further added.
[0035]
The slurry thus prepared was spray-dried with a rotary disk 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 fluidized and fired at 670 ° C. for 3 hours.
[0036]
Example 6
A catalyst having a composition of Fe ₃ Sb _3.3 Mo ₁₀ Bi _0.8 Fe _1.3 K _0.2 Ni _5.5 Cr _0.8 Ce _0.4 In _0.2 W _0.5 P _0.2 (SiO ₂ ) ₆₀ was prepared as follows.
19.2 g of ammonium paratungstate was dissolved in 3000 g of pure water, then 260 g of ammonium paramolybdate was mixed and dissolved, and 3.4 g of 85% phosphoric acid was further added. A solution prepared by dissolving 57.2 g of bismuth nitrate, 3.0 g of potassium nitrate, 235.5 g of nickel nitrate, 47.1 g of chromium nitrate, 25.6 g of cerium nitrate, 3.5 g of indium nitrate, and 25 g of citric acid was mixed with 270 g of 3.3% nitric acid. Subsequently, 2655.1 g of 20% silica sol was mixed. While stirring the slurry, 15% aqueous ammonia was added dropwise to adjust the pH to 5. This was heat-treated at 98 ° C. for 1.5 hours under reflux. A solution prepared by dissolving 77.4 g of iron nitrate and 25 g of citric acid in 270 g of pure water was added thereto, and 550 g of a 20% iron antimonate slurry prepared separately was further added thereto.
[0037]
The slurry thus prepared was spray-dried with a rotary disk spray dryer under conditions of 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 calcination at 670 ° C. for 3 hours.
[0038]
Example 7
A catalyst having a composition of Fe ₃ Sb _3.3 Mo ₁₀ Bi _0.5 Fe ₂ K _0.2 Ni ₄ Mg _1.5 Cr _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 the conditions shown in Table 1 Baked in. However, nitrates were used for the Al and Mg raw materials, and niobium hydrogen oxalate was used for the Nb raw material.
[0039]
Example 8
Composition is Fe _1.5 Sb _1.7 Mo ₁₀ Bi _0.5 Fe ₁ K _0.2 Ni ₄ Co _1.5 Cr ₂ Ce _0.5 Ru _0.05 Cs _0.05 P _0.3 A catalyst of (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 raw materials for Co, Ru and Cs.
[0040]
Example 9
Composition is Fe ₅ Sb _5.5 Mo ₁₀ Bi _0.5 Fe _1.3 K _0.2 Ni ₆ Cr ₁ Ce _0.2 Zr _0.2 P _0.1 A catalyst of (SiO ₂ ) ₃₅ was prepared in the same manner as in Example 6, and calcined under the conditions shown in Table 1. However, Zr raw material was zirconium oxynitrate.
[0041]
Example 10
Composition was prepared in the same manner as _{Fe 7 Sb 7.7 Mo 10 Bi 0.5} Fe 1.2 K 0.2 Ni 5.75 Cr 1.5 Ce 0.5 Sm 0. 1 Nd 0.1 V 0.1 Te 0.25 Catalyst Example 6 is a (SiO _{2) 35,} Firing was performed under the conditions shown in Table 1. However, nitrates were used for the Sm and Nd materials, ammonium metavanadate was used for the V materials, and telluric acid was used for the Te materials.
[0042]
Comparative Example 1
A catalyst having a composition of Fe ₃ Sb _3.3 Mo ₁₀ Bi _0.4 Fe _0.6 K _0.2 Ni ₆ Cr _0.8 Ce _0.4 P _0.2 B _0.2 (SiO ₂ ) ₃₅ was prepared in the same manner as in Example 1, and calcined under the conditions shown in Table 1. did.
[0043]
Comparative Example 2
A catalyst having a composition of Fe ₃ Sb _3.3 Mo ₁₀ Bi _0.4 Fe _1.1 K _0.2 Ni ₆ P _0.2 B _0.2 (SiO ₂ ) ₃₅ was prepared in the same manner as in Example 1, and calcined under the conditions shown in Table 1.
[0044]
Comparative Example 3
A catalyst having a composition of Fe ₃ Sb _3.3 Mo ₁₀ Bi _1.2 Fe _1.3 K _0.2 Ni _5.5 Zn _0.2 Cr _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 Table 1 It baked on the conditions of this.
[0045]
Comparative Example 4
A catalyst having a composition of Fe ₃ Sb _3.3 Mo ₁₀ Bi _0.4 Fe ₂ K _0.2 Ni ₆ Zn _0.2 Cr _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 Table 1 It baked on the conditions of this.
[0046]
The molybdenum-enriched catalysts used in Examples 7 to 10 and Comparative Examples 3 to 4 were prepared by impregnating an ammonium paramolybdate aqueous solution based on each catalyst, followed by drying and firing.
[0047]
Using the catalysts of these Examples and Comparative Examples, methanol ammoxidation reaction was performed under the above reaction conditions. The results are shown in the table below.
[0048]
[Table 1]

[0049]
【The invention's effect】
The hydrogen cyanide production method of the present invention provides a high yield of hydrogen cyanide and has a stable catalyst structure, so that the reaction stability over time is improved, and the catalyst performance can be maintained for a long time by replenishing and adding a molybdenum component. It is.

Claims (3)

A method for producing hydrogen cyanide, which comprises 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 (SiO2) y
(Wherein (Fe Sba) represents iron and antimony forming iron antimonate, Mo, Bi, Fe and K represent molybdenum, bismuth, iron and potassium, respectively, M represents magnesium, calcium and strontium And at least one element selected from the group consisting of barium, manganese, cobalt, nickel, zinc and cadmium, N is selected from the group consisting of chromium, lanthanum, cerium, praseodymium, neodymium, samarium, aluminum, gallium and indium At least one element, G is at least one element selected from the group consisting of ruthenium and palladium, Q is at least one selected from the group consisting of titanium, zirconium, vanadium, niobium, tantalum, tungsten, germanium, tin and lead Element R, from the group consisting of boron, phosphorus and tellurium At least one element selected, T is at least one element selected from the group consisting of lithium, sodium, rubidium and cesium, O is oxygen, Si is silicon, and the subscripts a, b, c, d, k, m , N, g, q, r, t, x and y represent atomic ratios, and when Mo = 10, a = 0.8-2, b = 0.5-20, c = 0.1-2, d = 0.3-3, k = 0.05 to 2, m = 3 to 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 above components are combined The number of oxygen in the metal oxide produced is y = 20 to 200. Furthermore, the product 20 of the valence and the atomic ratio of molybdenum as molybdic acid is expressed by bismuth, iron, potassium, M, N and T component elements. The number 20 / p divided by the sum p of the product of the valence and atomic ratio is 0.8-1. The method for producing hydrogen cyanide according to claim 1, wherein the reaction is carried out while adding a molybdenum-containing material. The method for producing hydrogen cyanide according to claim 2, wherein the molybdenum-containing material to be added is a molybdenum-enriched catalyst.