KR100193382B1 - Ammonia Oxidation Catalyst - Google Patents

Abstract

The present invention relates to a catalyst for ammonia oxidation reaction, and more particularly, to preparing a cyanide compound by ammonia oxidation of olefins with a five-component solid catalyst containing bismuth, iron, and nickel as the main component of molybdenum and phosphorus. It relates to a catalyst for ammonia oxidation represented by the following Chemical Formula 1 showing high conversion and selectivity.

[Formula 1]

_A · _b · P _c Mo Bi Fe · Ni · _{d e f} · O · X · Y / SiO ₂

In the above formula,

X is a cationic or anionic salt;

Y is water;

a, b, c, d, e and f represent the number of atoms, a, b, c, d and e are each an integer greater than 0 and less than or equal to 10, f is a, b, c, d, e It is a numerical value which changes according to the value of b, except that b / a = 0.2-5, c / a = 0.2-2, d / a = 0.1-5, and e / a = 0.1-5.

Description

Ammonia Oxidation Catalyst

The present invention relates to a catalyst for ammonia oxidation reaction, and more particularly, to preparing a cyanide compound by ammonia oxidation of olefins with a five-component solid catalyst containing bismuth, iron, and nickel as the main component of molybdenum and phosphorus. It relates to a catalyst for ammonia oxidation represented by the following Chemical Formula 1 showing high conversion and selectivity.

[Formula 1]

_A · _b · P _c Mo Bi Fe · Ni · _{d e f} · O · X · Y / SiO ₂

In the above formula,

X is a cationic or anionic salt;

Y is water;

a, b, c, d, e and f represent the number of atoms, a, b, c, d and e are each an integer greater than 0 and less than or equal to 10, f is a, b, c, d, e It is a numerical value which changes according to the value of b, except that b / a = 0.2-5, c / a = 0.2-2, d / a = 0.1-5, and e / a = 0.1-5.

Acrylonitrile, a typical cyanide compound, was prepared by reacting acetylene, ethylene oxide, and HCN, but this is avoided because the raw material is expensive. Currently, the ammonia oxidation reaction is mainly adopted for the industrial production of acrylonitrile and cyanide compounds, and it is also focusing on the development of catalysts for the ammonia oxidation reaction with better activity.

As a catalyst for the ammonia oxidation reaction, various cocatalysts are added to the Bi ₂ O ₃ -MoO ₃ series and the Mo-Bi-PO series catalysts, and the reaction temperature is also performed at atmospheric pressure in the range of 400 to 460 ° C. . Acrylonitrile prepared by the ammonia oxidation of propylene is polymerized in the presence of H ₂ O ₂ / Fe catalyst and used as a raw material for synthetic rubber and acrylic fiber such as ABS, AS, NBR, etc. Catalysts and Chemical Industry, Vol. 2 (1991)]. As such, cyanide is used as a core in all industries, and its use continues to be developed.

Bismuth-molybdenum oxide-based catalysts, which are typically used in the process of producing acrylonitrile, have added various promoters such as cobalt, iron, and alkali metals to improve selectivity and stability of the catalyst.

Reported examples of propylene ammonia oxidation catalysts are as follows.

In 1989, Standard Oil reported that the catalytic activity was increased by depositing pyrolysable materials, such as 1% boric acid and 2% molybdenum oxide, on the surface of molybdenum-based catalysts. 4,855,275].

In 1987, China Petrochemical Co., Ltd. [M / Mo / O] _L [A / B / C / Ni / Co / Na / Fe / Bi / Mo / O] _N (where L / N = 0.1 to It has been reported that acrylonitrile could be produced in a yield of 75.9% by adding metals such as M, A, B, and C to the multicomponent catalyst based on the present invention [Faming Zuanli Gongkai Shuomingshu CN 87,103,465].

In 1989, Nito Chemical Co., Ltd., based on molybdenum / bismuth / iron / nickel / silica, added potassium and the like to produce a catalyst having a propylene conversion of 98.8% [Japanese Patent No. 1,265,067]. It has been reported that a multicomponent catalyst composed of molybdenum / bismuth / iron / nickel / antimony / alkali metal / silica was developed to develop a catalyst capable of obtaining a propylene conversion of 99% (European Patent No. 337,779).

In 1989, Shanghai General Petrochemical Plant, based on molybdenum / bismuth / iron / chromium / manganese oxides, prepared a catalyst mixed with additives of A, B, C, and D on silica. Zuanli Shenqing Gongkai Shuomingshu CN 1,031,662].

In 1991, Asahi Chemical Co., Ltd. obtained 80.2% of acetonitrile at 460 ° C by oxidizing propylene ammonia on a catalyst supported with molybdenum / bismuth / iron / potassium / sodium / phosphorus on silica and in the presence of acetone. [Japanese Patent No. 3,246,269].

In 1991, China's Changchun Institute of Applied Chemistry developed 50% (nickel-cobalt-iron-bismuth-phosphorus-potassium-additive oxide) / 50% silica catalysts to determine the mechanism and structure of the active phase [Cuihua Xuebao, 1991 , 12 (6), 433-8].

In 1990, Nito Chemical Co., Ltd. applied iron-antimony-phosphorus-additive oxide / silica catalysts to oxygenated dehydrogenation, alkene aromatic compounds and ammonia oxidation of olefins. Acetonitrile was obtained with a yield of 72.1% [European Patent No. 404,529]. It was reported that% acetonitrile was obtained (European Patent 383,598).

In addition, Standard Oil Co., Ltd. has developed and reported a catalyst using an additive based on an antimony / bismuth / cerium / molybdenum oxide catalyst [US Pat. No. 4,921,828]. In 1990, Nito Chemical Co., Ltd. developed a process for producing a catalyst that reduces the combustibility of ammonia based on molybdenum / bismuth / iron or tellurium oxides.The catalyst was used to convert propylene to 98.5%, yielding 85.5%. It was reported that acetonitrile was obtained (Japanese Patent No. 259,046).

In Russia in 1990, cobalt / bismuth / molybdenum / nickel / iron oxides supported on silica were used to investigate the loading effects of silica [Zh, Fiz, Khim. 1990, 64 (8), 2179-85].

In 1989, Nito Chemical Co., Ltd. focused on the use of inexpensive metal catalysts with 98.1% conversion at 420 ° C using phosphorus / sodium or potassium / molybdenum / bismuth / iron / antimony / nickel oxides. (European Patent No. 331,351).

In 1988, the Changchun Institute of Applied Chemistry in China studied the effect of cerium on multicomponent oxides of phosphorus / molybdenum / bismuth / iron / cerium / potassium. Cerium inhibits the sublimation of molybdenum trioxide (MoO ₃ ) and stabilizes the active phase. [Yingyong Huaxue, 1988, 5 (2), 13-17].

In 1987, Mitsubishi Chemical Co., Ltd. reported that 99% of propylene conversion was obtained using a molybdenum / tungsten / bismuth / lead / boron / antimony / chromium or iron oxide catalyst as a catalyst supported on silica [Japanese Patent] 62,176,543].

In 1987, Standard Oil Co. investigated a method for preparing a catalyst based on bismuth-molybdenum. For example, potassium / nickel / cobalt / iron / chromium / bismuth / tungsten / molybdenum oxide supported on silica. Was prepared to establish optimal conditions [US Pat. No. 4,659,689].

In 1985, Levinta and Vasila used partial catalysts and ammonia with a catalyst containing molybdenum, bismuth, iron, copper, nickel, phosphoric acid and silica with 5-10% KOH added. Oxidation reaction was reported [Rom. RO 88,173].

In 1985, Standard Oil manufactured A / B / C / Iron / bismuth / molybdenum oxide catalysts (A is an alkali metal, B is cobalt or nickel or two mixtures, and C is phosphorus or arsenic or two mixtures). It has been reported to show high activity even at low temperatures.

In 1982, A / D / E / G / iron / bismuth / molybdenum oxide catalysts (A for rare earth metals, D for alkali metals, E for nickel, cobalt, zinc, cadmium, calcium or mixtures thereof, G for phosphorus, boron, Arsenic or a mixture thereof) was applied to ammonia oxidation of olefins to obtain high activity, and in particular, the activity of Ni _10.5 FeBiPMoO ₅₇ / SiO ₂ catalyst was measured and compared. [US Pat. No. 4,192,776,4,503,001 number]. However, the catalysts exemplified in these patents contain excess nickel and molybdenum. In general, the higher the content of nickel in the catalyst consisting of the constituents, the lower the activity of the catalyst and the reaction proceeds unstable, and if the content of molybdenum is excessive, the activity of the catalyst is reduced by the sublimation of molybdenum trioxide and the catalyst loss during the reaction. Compositional changes may occur. Therefore, excessive use of nickel or molybdenum should be avoided.

As described above, all catalysts for ammonia oxidation reactions are multi-component oxides, which increase the activity of the reactants and the stability of the catalysts by various components, and to identify mechanisms and active phases by various characteristics analysis. It was. However, the disadvantage of the multi-component catalyst is that there is a limit in the characterization through characterization, in particular, it does not help much in identifying the reaction activity or the reaction path and activity for the active phase.

Therefore, it is desirable to develop a catalyst having a minimum component and maximum activity rather than a multicomponent catalyst in terms of economic and research value.

In addition, since the activity of the catalyst is very different depending on the type of reactor used, product analysis method, reaction conditions (pretreatment and reaction temperature, contact time, amount of catalyst), etc. Is not easy and should always be considered. Therefore, the focus of new catalyst development is to include the minimum amount of components and show the maximum effect on the reactants, that is, increase in activity as described above.

Therefore, the inventors of the present invention have tried to develop a new catalyst that can improve the conversion of olefins and the selectivity of cyanide during ammonia oxidation of olefins, even though they contain minimal components. Including bismuth, iron, and nickel in an appropriate proportion, the reaction activity is increased, as well as the catalyst component is significantly reduced compared to the previously reported patents. The present invention was completed by finding that there is a great difference in hygroscopicity and reaction activity.

The present invention comprises five kinds of components, and an object thereof is to provide a five-component solid catalyst that exhibits high conversion and selectivity in ammonia oxidation of olefins.

The present invention is a solid catalyst containing molybdenum (Mo), phosphorus (P), bismuth (Bi), iron (Fe) and nickel (Ni), the solid catalyst for ammonia oxidation reaction represented by the following formula (1) It is characterized by a solid catalyst.

[Formula 1]

_A · _b · P _c Mo Bi Fe · Ni · _{d e f} · O · X · Y / SiO ₂

Wherein X, Y, a, b, c, d, e and f are as defined above, respectively.

Referring to the present invention in more detail as follows.

According to the present invention, molybdenum (Mo), phosphorus (P), bismuth (Bi), iron (Fe), and nickel (Ni) are contained in specific composition ratios. The present invention relates to a five-component solid catalyst of a novel composition useful for preparing cyanide compounds.

Referring to the manufacturing process of the solid catalyst according to the present invention in more detail.

First, a salt containing molybdenum is added to water, and the temperature is gradually raised to completely dissolve. Then, the silica sol is mixed with a desired ratio while stirring. To this is added a salt containing bismuth, iron and nickel, respectively, followed by phosphoric acid (H ₃ PO ₄ ). Then, the mixed solution is adjusted to pH 2-5 by adding an acid or base solution, and concentrated by removing water with heating and stirring at around 100 ° C. in order to adjust the reaction rate and easily remove the residue to prepare a solid product. The resulting solid product is dried in an oven at 30 to 150 ° C. for 1 to 15 hours to completely remove moisture, and then calcined at 200 ° to 400 ° C. for 1 to 5 hours and at 400 ° to 600 ° C. for 1 to 5 hours to produce 10 to 100 mesh. After pulverizing (mesh), it is baked at 500-700 degreeC for 1 to 5 hours.

The active ingredient used in the preparation of the solid catalyst of the present invention as described above is added in the form of a salt, these salts are relatively well soluble in water has a condition that can be uniformly mixed during the production of the catalyst . For example, a salt containing molybdenum is ammonium molybdatetetrahydrate (NH ₄ ) ₆ Mo ₇ O ₂₄ 4H ₂ O], and a salt containing bismuth is bismuth nitrate pentahydrate, Bi ( NO ₃ ) ₃ · 5H ₂ O], and salts containing iron include iron (III) nitrate nonahydrate, Fe (NO ₃ ) ₃ .9H ₂ O], and salts containing nickel. It is particularly preferable to use nickel nitrate hexahydrate, Ni (NO ₃ ) ₂ .6H ₂ O.

In addition, each active ingredient is to be contained within the content range of the formula (1), the activity of the catalyst can vary greatly depending on the content of each ingredient. In the case of molybdenum, when the mole ratio of Mo / Bi is less than 0.2, it is not reactive, and when it exceeds 5, molybdenum trioxide is generated during the reaction and sublimation occurs, resulting in loss of the catalyst. In the case of phosphorus, if the molar ratio of P / Bi is less than 0.2, the reaction activity is sharply lowered, and if it is more than 2, there is a problem that the oxidation reaction is excessively progressed by increasing the hygroscopicity of the catalyst and increasing acidity. In the case of iron, when the molar ratio of Fe / Bi is less than 0.1, the conversion of propylene is lowered, and the use of excess of 5 does not affect the activity of the catalyst.

The solid catalyst of the present invention prepared by the above-described manufacturing process is almost yellow ocher color and has a low hygroscopicity to moisture and is easy to store.

The solid catalyst of the present invention prepared by the above production method was confirmed its composition by a specific surface area and pore volume measuring instrument, infrared spectroscopy analyzer, thermogravimetric analyzer, X-ray diffraction analyzer.

In order to measure the activity of the catalyst prepared as described above, after filling the catalyst in the SUS 316 reactor, the composition of the incoming reactant was propylene / ammonia / oxygen / nitrogen = 1/1 / 2.52 / 9.48 (molar ratio) and the contact time was The ammoxidation reaction was performed at the reaction temperature of 455 degreeC by 3.6 second.

Hereinafter, the present invention will be described in more detail with reference to the following Examples, but the present invention is not limited thereto.

Example 1

Preparation of 50% (Bi, Mo, P _0.6 , Fe _0.8 , Ni _0.8 oxide) / 50% SiO ₂ catalyst

3.64 g of ammonium molybdate ((NH ₄ ) ₆ Mo ₇ O ₂₄ .4H ₂ O) was dissolved in 30 ml of water with gentle heating, and 28.6 g of silica sol was added with stirring (A solution). And nitrate of bismuth _{[Bi (NO 3) 2 ·} 5H 2 O] 10 g, iron nitrate _{[Fe (NO 3) 2 ·} 9H 2 O] 6.67 g and nickel nitrate _{[Ni (NO 3) 2 ·} 6H 2 O] 4.80 A solution was prepared by dissolving g in 20 ml of 10% nitric acid (B solution). The solution A prepared above was added to the solution B. Then, 1.43 g of 85% phosphoric acid was added and 25% aqueous ammonia was added to adjust the pH of the solution to 3 (nickel = 0.8).

Example 2

50% (Bi, Mo, P _0.6 , Fe _0.8 , Ni _0.2 oxide) / Production of 50% SiO ₂

Nickel nitrate [Ni (NO ₃ ) ₂ .6H ₂ O] was prepared in the same manner as in Example 1 except that 1.20 g was used instead of 4.80 g (nickel = 0.2).

Example 3

50% (Bi, Mo, P _0.6 , Fe _0.8 , Ni _0.4 oxide) / Preparation of 50% SiO ₂

Nickel nitrate [Ni (NO ₃ ) ₂ .6H ₂ O] was prepared in the same manner as in Example 1 except that 2.40 g was used instead of 4.80 g (nickel = 0.4).

Example 4

50% (Bi, Mo, P _0.6 , Fe _0.8 , Ni _0.6 oxide) / Preparation of 50% SiO ₂

Nickel nitrate [Ni (NO ₃ ) ₂ .6H ₂ O] was prepared in the same manner as in Example 1 except that 3.60 g was used instead of 4.80 g (nickel = 0.6).

Example 5

50% (Bi, Mo, P _0.6 , Fe _0.8 , Ni _1.0 oxide) / Preparation of 50% SiO ₂

Nickel nitrate [Ni (NO ₃ ) ₂ .6H ₂ O] was prepared in the same manner as in Example 1 except that 6.00 g was used instead of 4.80 g (nickel = 1.0).

Example 6

50% (Bi, Mo, P _0.6 , Fe _0.8 , Ni _1.2 oxide) / Preparation of 50% SiO ₂

Nickel nitrate [Ni (NO ₃ ) ₂ .6H ₂ O] was prepared in the same manner as in Example 1 except that 7.20 g was used instead of 4.80 g (nickel = 1.2).

Comparative Example 1

Preparation of 50% (Bi, Mo, P _0.6 , Fe _0.8 ) / 50% SiO ₂

It was prepared in the same manner as in Example 1 except that nickel nitrate was not added.

Comparative Example 2

Preparation of 50% (BiMoMo P _0.6 ) / 50% SiO ₂

It was prepared in the same manner as in Example 1, except that nickel nitrate and iron nitrate were not added.

Comparative Example 3

50% (Bi, Mo, P _0.6 , Fe _0.8 , Ni ₆ oxide) / Preparation of 50% SiO ₂

Nickel nitrate [Ni (NO ₃ ) ₂ .6H ₂ O] was prepared in the same manner as in Example 1, except that 36 g was used instead of 4.80 g (nickel = 6).

Experimental Example

In order to observe the activity of the catalysts prepared in Examples 1 to 6 and Comparative Examples 1 to 3, 1.5 cc of catalyst was charged to a SUS 316 reactor having an inner diameter of 10.75 mm and a length of 160 mm, and the reaction mixture was brought to have a contact time of 3.6 seconds. Ammonia oxidation was carried out at 455 ° C. with propylene / ammonia / oxygen / nitrogen = 1/1 / 2.52 / 9.48 (molar ratio).

TABLE 1

According to the results of Table 1, the conversion rate and selectivity may vary depending on the composition of the active metal, in particular, there is a large difference in conversion rate and selectivity depending on the content of nickel or the addition of nickel and iron. In addition to nickel, molybdenum and phosphorus are used as the basis, and the results vary greatly depending on the amount of bismuth and iron.

The present invention focuses on the development of a catalyst for ammonia oxidation according to the nickel content. It can be seen that the five-component solid catalyst of the present invention exhibits a very high activity (in acrylonitrile production) by exhibiting about 90% conversion for propylene and about 80% for acrylonitrile.

Particularly, in the present invention, only five economic aspects of the multi-component catalysts known to date are made up of components that have high activity. In the ammonia oxidation of the catalysts disclosed in the existing patents and literatures, there are no mentions of additional products such as acetonitrile, acrolein and other by-products, but the present invention can control the production of these additional products.

Claims (2)

In a solid catalyst containing molybdenum (Mo), phosphorus (P), bismuth (Bi), iron (Fe) and nickel (Ni), the solid catalyst is represented by the following formula (1) Solid catalyst. [Formula 1] _A · _b · P _c Mo Bi Fe · Ni · _{d e f} · O · X · Y / SiO ₂ In the above formula, X is a cationic or anionic salt; Y is water; a, b, c, d, e and f represent the number of atoms, a, b, c, d and e are each an integer greater than 0 and less than or equal to 10, f is a, b, c, d, e It is a numerical value which changes according to the value of b, except that b / a = 0.2-5, c / a = 0.2-2, d / a = 0.1-5, and e / a = 0.1-5. The method of claim 1, wherein Mo is ammonium molybdate [(NH ₄ ) ₆ Mo ₇ O ₂₄ .4H ₂ O], and Bi is bismuth nitrate [Bi (NO ₃ ) ₃ .5H ₂ O]. A solid catalyst for ammonia oxidation, characterized in that it is derived from silver iron nitrate [Fe (NO ₃ ) ₃ · 9H ₂ O] and Ni is derived from nickel nitrate [Ni (NO ₃ ) ₂ · 6H ₂ O], respectively. .