KR101340621B1 - Ferrite metal oxide catalysts using the spray-pyrolysis process, preparing method thereof and preparing method of 1,3-butadiene using the same - Google Patents

Abstract

The present invention relates to a method for producing ferrite metal oxide catalysts using a spray-pyrolysis process and catalysts and, more specifically, to a method for producing 1,3-butadiene is metal oxide catalyst which is prepared from a metal oxide precursor by a spray-pyrolysis process of metal, containing iron as a main catalyst and magnesium, manganese, or zinc as a cocatalyst; and a method for preparing 1,3-butadiene through oxidative dehydrogenation of n-butadiene using the same. [Reference numerals] (AA) Spray pyrolysis method;(BB,HH) Zinc (or magnesium, manganese) precursor;(CC,II) Iron precursor;(DD,JJ) Zinc (or magnesium, manganese)-iron mixed solution;(EE) Spray pyrolysis;(FF) Zinc-Iron ferrite metal oxide catalyst;(KK) Coprecipitation agent (4N sodium hydroxide, pH adjustment);(LL) Coprecipitation solution (mixing);(MM) Hydrothermal reaction and aging;(NN) Filtering and washing;(OO) Drying (120 °C, 4 hours);(PP) Drying (120 °C, 24 hours);(QQ) Plasticizing (650 °C, 4 hours);(RR) Zinc-iron ferrite metal oxide catalyst

Description

Ferrite metal oxide catalysts using the spray-pyrolysis process, preparing method etc. and preparing method of 1,3-Butadiene using the same }

The present invention relates to a method for preparing a ferrite metal oxide catalyst using a spray pyrolysis method, and more particularly, to a spray pyrolysis method in a metal oxide precursor including iron as a main catalyst and magnesium, manganese or zinc as a cocatalyst. And a method for producing 1,3-butadiene through an oxidative dehydrogenation of n -butene using the metal oxide catalyst prepared by the present invention.

1,3-butadiene, the main raw material of tires, which is growing in demand due to the growth of the automobile market every year, is usually produced by naphtha cracking of saturated hydrocarbons. Pyrolysis of naphtha results in a mixture of methane, ethane, ethylene, acetylene, propane, propylene, butane, butene, 1,3-butanediene and higher hydrocarbons of C ₅ or higher. The production of 1,3-butadiene through the above pyrolysis method is responsible for most of the total 1,3-butadiene supply, but other olefins, which are by-products as described above, are also synthesized and the energy cost required for the pyrolysis process is increased. The method of producing 1,3-butadiene is very inefficient.

Another manufacturing method is a method of directly dehydrogenating n -butene. In this method, the yield of 1,3-butadiene is higher than that of naphtha pyrolysis, but because of the endothermic reaction, a large amount of energy is required to maintain a high temperature reaction temperature, and carbon deposits are formed on the surface of the catalyst to activate the catalyst. Its disadvantage is that it requires a lot of energy for catalyst regeneration.

Overcoming this drawback is the oxidative dehydrogenation method of producing 1,3-butadiene by directly reacting n -butene with oxygen. The oxidative dehydrogenation process is carried out in the presence of steam. The added steam acts as a heat transporter and promotes vaporization of organic deposits on the catalyst, thus inhibiting carbonization of the catalyst to prevent deactivation. In addition, n -butene reacts with oxygen to convert 1,3-butadiene and water, and the water produced therein is stable and thermodynamically advantageous, and can lower the reaction temperature. In other words, oxidative dehydrogenation is thermodynamically stable and has good selectivity to olefins at low temperatures. In general, in the oxidative dehydrogenation reaction, radicals generated at the beginning of the reaction are important reaction intermediates, desorb from the surface of the catalyst during the reaction, move to the gas part, and participate in the homogeneous catalytic reaction. However, the oxidative dehydrogenation method in which n -butene and oxygen react to produce 1,3-butadiene is accompanied by side reactions such as partial oxidation and complete oxidation because oxygen is used as a reactant, and thus, these side reactions are suppressed to prevent 1,3 Developing catalysts with high selectivity and yield of butadiene is a key technology. Suitable catalysts for the preparation of 1,3-butadiene in n -butene by the oxidative dehydrogenation method are bismuth-molybdenum based oxides [APV Soares, LK Kimitrov, MCA Oliveira, L. Hilaire, MF Portela, RK Grasselli, Appl. Catal. A: Gem., Vol. 253, 191 (2003); P. Boutry, R. Montarnal, J. Wrzyszcz, J. Catal., Vol. 13, p. 75 (1969) ( β- Bi ₂ Mo ₂ O ₉ , γ- Bi ₂ MoO ₆ ); JC, Jung, H. Kim, AS Choi, Y.-M. Chung, TJ Kim, SJ Lee, S.-H. Oh, IK Song, J. Mol. Catal. A: Chem., Vol. 259, p. 166 (2006) ( α- Bi ₂ Mo ₃ O ₁₂ , β- Bi ₂ Mo ₂ O ₉ , γ- Bi ₂ MoO ₆ ) and ferrite catalyst [HH Kung, B. Kundalkar, MC Kung, WH Cheng, J. Phys. Chem., 84, 382 (1980); JA Toledo-Antonio, N. Nava, M. Martinez, X. Bolhimi, Appl. Catal. A: Gen., vol. 234, p. 137 (2002); H. Lee, JC Jung, H. Kim, Y.-M. Chung, TJ Kim, SJ Lee, S.-H. Oh, YS Kim, IK Song, Catal. Commun., Vol. 9, p. 1137 (2008); H. Lee, JC Jung, H. Kim, Y.-M. Chung, TJ Kim, SJ Lee, S.-H. Oh, YS Kim, IK Song, Catal. Lett., Vol. 122, p. 281 (2008); Korean Patent No. 10-0847206; Korean Patent No. 10-0888143; US Patent Publication No. 2012-0059208 or based on bismuth-molybdenum multiple metal oxide catalyst further comprising iron (US Pat. No. 4,423,281; US Patent No. 4,336,409; US Patent No. 3,110,746.

Among these catalysts, the ferrite catalyst has a spinel crystal structure, and the yield of 1,3-butadiene varies greatly in the oxidative dehydrogenation of n -butene depending on the type of divalent cation. In particular, zinc, manganese and magnesium ferrite have been reported to have higher selectivity of 1,3-butadiene than other types of metal ferrites (US Pat. No. 3,334,152; US Patent No. 3,284,536; US Patent No. 3,303,234; US Patent No. 3,849,545; US Patent 4,658,074; US Patent No. 3,937,748; Republic of Korea Patent No. 10-0888143].

In carrying out the oxidative dehydrogenation of n -butene, all of the ferrite catalysts of the above patents are subjected to oxidative dehydrogenation of n -butene using a ferrite catalyst having a spinel structure prepared by a physical mixing and coprecipitation method. As the preparation of 1,3-butadiene, the coprecipitation method is typically used in the preparation of a metal oxide catalyst, but 1) dissolving the precursor of the active metal, 2) alkaline coprecipitation in a solution in which the active metal precursor is dissolved Several steps such as adding a solution, 3) aging after coprecipitation, filtration and washing of the coprecipitated solution, 4) drying the obtained solid, and 5) calcining and activating the dried solid catalyst. There is a problem that wastewater is generated during the filtration and washing process after preparing the catalyst.

1. Republic of Korea Patent No. 10-0847206 2. Republic of Korea Patent No. 10-0888143 3. United States Patent Publication No. 2012-0059208 4. U.S. Patent 4,423,281 5. US Patent No. 4,336,409 6. US Patent No. 3,110,746 7. U.S. Patent No. 3,334,152 8. US Patent No. 3,284,536 9. US Patent No. 3,303,234 10. US Patent No. 3,849,545 11.U.S. Patent 4,658,074 12. US Patent No. 3,937,748

1.A.P.V. Soares, L.K. Kimitrov, M.C.A. Oliveira, L. Hilaire, M.F. Portela, R.K. Grasselli, Appl. Catal. A: Gem., Vol. 253, p. 191 (2003), 2.P. Boutry, R. Montarnal, J. Wrzyszcz, J. Catal., Vol. 13, p. 75 (1969) (β-Bi2Mo2O9, γ-Bi2MoO6) 3. J.C, Jung, H. Kim, A.S. Choi, Y.-M. Chung, T.J. Kim, S.J. Lee, S.-H. Oh, I.K. Song, J. Mol. Catal. A: Chem., Vol. 259, p. 166 (2006) (α-Bi2Mo3O12, β-Bi2Mo2O9, γ-Bi2MoO6) 4. H.H. Kung, B. Kundalkar, M.C. Kung, W.H. Cheng, J. Phys. Chem., 84, 382 (1980), J.A. Toledo-Antonio, N. Nava, M. Martinez, X. Bolhimi, Appl. Catal. A: Gen., vol. 234, p. 137 (2002) 5. H. Lee, J.C. Jung, H. Kim, Y.-M. Chung, T.J. Kim, S.J. Lee, S.-H. Oh, Y.S. Kim, I.K. Song, Catal. Commun., Vol. 9, p. 1137 (2008) 6, H. Lee, J. C. Jung, H. Kim, Y.-M. Chung, T.J. Kim, S.J. Lee, S.-H. Oh, Y.S. Kim, I.K. Song, Catal. Lett., Vol. 122, p. 281 (2008)

Accordingly, the present inventors have found that a catalyst having a uniform composition can be prepared by using an aqueous solution in which a metal precursor, which is a catalyst composition, is completely dissolved in water, without using a coprecipitation solution as a catalyst composition for n -butene oxidative dehydrogenation reaction. It was found that, by spray pyrolysis alone, the ferrite catalyst was simply developed economically and conveniently compared to the conventional method, and applied to the oxidative dehydrogenation of n -butene to maximize the production of 1,3-butadiene.

That is, in order to overcome the problems of the prior art, an effort was made to develop a ferrite catalyst having high activity in the oxidative dehydrogenation of n -butene without going through several stages of the catalyst preparation process, and the active metal precursor was dissolved in water. When the spray pyrolysis method is used without the coprecipitation step, it is possible to prepare a ferrite catalyst for preparing 1,3-butadiene, which is simpler than the conventional method. It was found that butadiene can be prepared to complete the present invention.

Accordingly, an object of the present invention is to provide a ferrite catalyst having high selectivity and yield of 1,3-butadiene in oxidative dehydrogenation of n -butene.

Another object of the present invention is to provide a method for producing a ferrite catalyst having high selectivity and yield of 1,3-butadiene by a simple process using spray pyrolysis.

Another object of the present invention is to provide a method for producing 1,3-butadiene having high selectivity and yield of 1,3-butadiene using the catalyst.

In order to solve the above problems, the present invention is to dissolve the precursor of the divalent metal and the precursor of iron in distilled water so that the molar ratio of at least one divalent metal and iron selected from magnesium, zinc and manganese is 1: 1.8 to 2.2. A first step of preparing a mixed solution; A second step of forming a catalyst powder by thermally pyrolyzing at a temperature of 600 to 1200 ° C. while spraying the mixed solution of the first step into a high temperature reactor using air of 1 to 7 atm by a gas spray method; It provides a method for producing a ferrite metal oxide catalyst, characterized in that.

In addition, the present invention is composed of a powder of a spray pyrolysis of the mixed solution of the precursor of the divalent metal and the precursor of iron so that the molar ratio of at least one divalent metal and iron selected from magnesium, zinc and manganese is 1: 1.8 to 2.2. It provides a ferrite metal oxide catalyst having a surface area of 20 to 100 m 2 / g, pore volume of 0.18 to 1 cm 3 / g.

The present invention also provides a method for producing 1,3-butadiene by oxidative dehydrogenation of n -butene in the presence of the ferrite metal oxide catalyst as described above.

As described above, the method for preparing the ferrite catalyst according to the present invention can be prepared using a spray pyrolysis method, so that the preparation of the ferrite catalyst can be made by a relatively simple synthetic route compared to the existing coprecipitation method, and thus the manufacturing time is shortened. It is advantageous to secure reproducibility.

In addition, the ferrite metal oxide catalyst prepared using the spray pyrolysis method according to the present invention as described above is superior in the selectivity of 1,3-butadiene compared to the ferrite metal oxide catalyst prepared using the conventional coprecipitation method of high yield. 1,3-butadiene can be produced and is very useful for mass production of 1,3-butadiene.

1 is a manufacturing process chart of the ferrite metal oxide catalyst prepared in Examples 1 to 3 and Comparative Examples 1 to 2 according to the present invention.
2 is a comparison result of the X-ray diffraction pattern and the main components of the ferrite metal oxide catalyst prepared in Examples 1 to 3 of the present invention.
3 is a comparison result of the X-ray diffraction pattern and the main components of the ferrite metal oxide catalyst prepared in Comparative Examples 1 and 2 of the present invention.
4 is a scanning electron microscope measurement result of the ferrite metal oxide catalyst prepared in Examples 2, 4 to 5 according to the present invention.
5 is a scanning electron microscope measurement result of the ferrite metal oxide catalyst prepared in Comparative Examples 1 and 2 of the present invention.

Hereinafter, the present invention will be described in more detail as one embodiment.

The present invention is characterized in that a ferrite metal oxide catalyst is prepared in the form of a catalyst powder by dissolving one or more precursors of divalent metal and iron selected from magnesium, zinc and manganese in distilled water at a specific molar ratio and pyrolyzing them by gas spraying. .

In the first step of the catalyst manufacturing process of the present invention, the divalent metal precursor and the iron precursor are dissolved in distilled water such that the molar ratio of at least one divalent metal selected from magnesium, zinc and manganese and iron is 1: 1.8 to 2.2. Prepare a mixed solution.

The precursor of the divalent metal used in the present invention may be used in the art, and is not particularly limited, but the iron precursor and the divalent metal precursor are selected from nitrate precursor, sulfate precursor, chloride precursor and carbonate precursor. It is preferable to use species or more. More preferred specific examples of the iron precursor are iron nitrate (Iron (III) nitrate), the zinc precursor is zinc nitrate (Zinc (II) nitrate), the magnesium precursor is magnesium nitrate (Magnesium (II) nitrate), and manganese It is preferable to use manganese nitrate (Manganese (II) nitrate) as the precursor.

In addition, in order to increase the solubility of each precursor used in preparing the mixed solution of the first step, by maintaining the temperature of the solution 10 ~ 80 ℃, preferably 15 ~ 60 ℃, more preferably 25 ~ 40 ℃ It is desirable to allow the precursor to dissolve completely.

In the second step in the catalyst preparation method of the present invention, the mixed solution of the first step is thermally pyrolyzed at a temperature of 600 to 1200 ℃ while spraying into the high temperature reactor using a gas of 1 to 7 atm by air spraying catalyst Form a powder.

In the second step, the mixed solution of the first step is introduced into a spray pyrolysis apparatus to produce a catalyst powder by a spray spray pyrolysis method. The catalyst powder is prepared by a spray spray pyrolysis method. Atmospheric pressure, preferably 1.5 to 5 atm, more preferably 2 to 4 atm, and the internal temperature of the spray pyrolysis apparatus is 600 to 1200 ° C, preferably 650 to 1000 ° C, more preferably 700 to 900 ° C. The ferrite catalyst obtained by uniformly dispersing an active metal component composed of a divalent metal and iron can be obtained. If the internal temperature of the spray pyrolysis apparatus is too low, there may be a problem that the desired catalyst crystals cannot be obtained. If the temperature is too high, the catalyst may melt to form a high melt, or the crystal structure of the catalyst may change, thus maintaining a temperature within the above range. It is desirable to. At this time, it is better to maintain the pressure in consideration of the correlation with temperature. If the pressure is too low, it is difficult to form a catalyst of desirable physical properties, and if it is too high, the process is difficult and economically disadvantageous, but due to high melt formation or deformation of crystal structure. This can result in lower catalyst performance.

As such, the catalyst is prepared in a powder form in which the mixed solution of the precursor of the divalent metal and the precursor of iron is spray pyrolyzed so that the molar ratio of at least one divalent metal selected from magnesium, zinc and manganese and iron is 1: 1.8 to 2.2. The catalyst is then made of a ferrite metal oxide catalyst having a surface area of 20 to 100 m 2 / g and a pore volume in the range of 0.18 to 1 cm 3 / g. At this time, if the surface area and pore volume of the catalyst is too small, the contact area of n -butene and the catalyst is small, and the conversion rate is low. If the catalyst is too large, the contact time increases and the amount of by-products is increased.

Ferrite metal oxide catalyst according to the present invention as described above is n - 1, 3-butadiene as a catalyst for butene from n - and the conversion of n-butene 75 to 90%, preferably 84 ~ 90%, of 1,3-butadiene Selectivity is 72 to 90%, preferably 80 to 90%.

The ferrite metal oxide catalyst of the present invention is characterized in that the powdery catalyst itself has high durability, long life and high reaction activity without a support. Therefore, it can be used without using a support separately. According to the present invention, the powdered ferrite metal oxide catalyst of the present invention may further include a support, if necessary. When the support is included, the support is not particularly limited, but one selected from alumina, silica, or silica-alumina may be used. It is preferable to use.

Meanwhile, the ferrite metal oxide catalyst prepared according to the present invention is used as a catalyst for the preparation of 1,3-butadiene, and the present invention provides an oxidative dehydrogenation reaction of n -butene in the presence of the ferrite metal oxide catalyst as described above. It includes a method for producing 1,3-butadiene.

The reactants for the reaction in the oxidative dehydrogenation of n -butene used in the method for producing 1,3-butadiene using the catalyst of the present invention further include a mixture of air and steam in addition to n -butene. N -butene is preferably used in a C ₄ mixture having a content of 50 to 75% by weight. Herein, the C ₄ mixture may include 0.5 to 25% by weight of n -butane and include 0.5 to 10% by weight of impurities except n -butene and n -butane. The mixing ratio of the reactants is n -butene: air: steam = 4 to 12% by volume: 15 to 45% by volume: 45 to 80% by volume is more preferable, more preferably 5 to 9% by volume: 16 to 30% by volume: 60 It is recommended to use the volume ratio of ~ 78% by volume. The air refers to general air containing 79% by volume of nitrogen and 21% by volume of oxygen. When the mixing ratio of the reactants is outside the above range, the reaction activity may decrease or the by-products may increase. The injection amount of n -butene and air may be controlled by a mass flow controller, and the injection amount of steam may be controlled by a microflow pump.

The injection amount of the reactant may be injected at a space velocity of 150 to 700 h ⁻¹ based on n -butene (GHSV, Gas Hourly Space Velocity), preferably at a space velocity of 175 to 600 h ⁻¹ , and more preferably. Preferably it is injected at a space velocity of 200 ~ 500 h ^-1 . If the space velocity is less than 150 h ^-1, the amount of the product per unit time may be low, and there may be a problem in profitability. If the space velocity exceeds 700 h ^{- 1} , the time for n -butene to react with the catalyst is short, resulting in an increase in unreacted product. The yield of 1,3-butadiene can be lowered.

And the oxidative dehydrogenation reaction is preferably performed under the temperature range of 300 ~ 500 ℃, preferably 330 ~ 470 ℃, more preferably 350 ~ 450 ℃ temperature range, when the reaction temperature is less than 350 ℃ If the temperature is too low to perform, and the catalyst may be that not active and not become a problem, the partial oxidation reaction well, reaction at temperatures in excess of 500 ℃ C ₁ Maintaining the temperature in the above range may be a problem because decomposition products or complete oxidation of C ₃ may occur.

Ferrite metal oxide catalyst prepared by the spray pyrolysis method of the present invention has a simpler manufacturing method than the conventional ferrite oxide catalyst for producing 1,3-butadiene, which is advantageous for securing reproducibility, and has a high yield because of excellent reaction activity and selectivity. , 3-butadiene can be prepared.

The ferrite metal oxide catalyst prepared by the spray pyrolysis method further includes a mixed gas of air and steam in addition to n -butene as an oxidative dehydrogenation reaction of n -butene, and n -butene has a content of 50 to 75 weight percent C ₄ mixture is used. The C ₄ mixture contains 0.5-25 wt% of n -butane and contains 0.5-10 wt% of impurities except n -butene and n -butane. The mixing ratio of the reactants is n -butene: air: steam = 4 to 12% by volume: 15 to 45% by volume: 45 to 80% by volume is preferred, more preferably 5 to 9% by volume: 16 to 30% by volume: 60 It is recommended to use the volume ratio of ~ 78% by volume. The air refers to general air containing 79% by volume of nitrogen and 21% by volume of oxygen. When the mixing ratio of the reactants is outside the above range, the reaction activity may decrease or the by-products may increase. The injection amount of n -butene and air can be controlled by a mass flow controller, and the injection amount of steam is controlled by a microflow pump.

The injection amount of the reactant may be injected at a space velocity of 150 to 700 h ⁻¹ based on n -butene (GHSV, Gas Hourly Space Velocity), preferably at a space velocity of 175 to 600 h ⁻¹ , and more preferably. Preferably it is injected at a space velocity of 200 ~ 500 h ^-1 . If the space velocity is less than 150 h ^-1 , there may be a problem in profitability due to the small amount of product per unit time, and if it exceeds 700 h ^-1 , the time for n -butene to react with the catalyst is short, resulting in an increase in unreacted substances. The yield of, 3-butadiene may be lowered.

And the oxidative dehydrogenation reaction is preferably performed under the temperature range of 300 ~ 500 ℃, preferably 330 ~ 470 ℃, more preferably 350 ~ 450 ℃ temperature range, when the reaction temperature is less than 350 ℃ If the temperature is too low, there may be a problem that the partial oxidation reaction does not occur well because the catalyst is not activated, and when the reaction is performed at a temperature exceeding 500 ° C., decomposition products or complete oxidation of C ₁ to C ₃ may occur. Therefore, it is preferable to maintain the temperature in the above range.

Ferrite metal oxide catalyst prepared by the spray pyrolysis method of the present invention has a simpler manufacturing method than the conventional ferrite oxide catalyst for producing 1,3-butadiene, which is advantageous for securing reproducibility, and has a high yield because of excellent reaction activity and selectivity. , 3-butadiene can be prepared.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the examples.

Example 1 Preparation of Zinc-Iron Ferrite Metal Oxide Catalysts

A zinc-iron ferrite metal oxide catalyst was prepared by spray pyrolysis based on the process diagram shown in FIG. 1.

1017.1 g of iron nitrate (Fe (NO ₃ ) ₃ · 9H ₂ O, SAMCHUN, 98%) and 384.2 g of zinc nitrate (Zn (NO ₃ ) ₂ · 6H ₂ O, SAMCHUN, 98%) were added to 1,500 g of distilled water. The solution was sufficiently stirred at 2 hours for 2 hours to prepare a solution containing zinc / iron at 1.0 / 2.0 molar ratio. Thereafter, the prepared mixed solution was pyrolyzed by spraying air into the reactor of the spray pyrolysis apparatus with air as a transport gas at 0.75 L per hour. At this time, the spray pyrolysis conditions were the zinc-iron ferrite metal oxide catalyst was prepared by operating the air pressure of 3 atm, reactor temperature of 750 ℃.

Examples 2 to 3: Preparation of magnesium-iron, manganese-iron ferrite metal oxide catalyst

The ferrite metal oxide catalyst was prepared in the same manner as in Example 1 except that the divalent metal was changed to zinc and manganese. Preparation of the mixed solution was performed in Example 2, iron nitrate (Fe (NO ₃ ) ₃ · 9H ₂ O, SAMCHUN, 98%) 1017.1 g and magnesium nitrate (Mg (NO ₃ ) ₂ · 6H ₂ O, 98%, SAMCHUN ) 324.4 g was added to 1,500 g of distilled water, and the mixture was sufficiently stirred at room temperature for 2 hours to prepare a solution containing magnesium / iron in a molar ratio of 1.0 / 2.0. In Example 3, iron nitrate (Fe (NO ₃ ) ₃ · 1017.1 g of 9H ₂ O, SAMCHUN, 98%) and 366.9 g of manganese nitrate (Mn (NO ₃ ) ₂ · 4H ₂ O, 98%, SAMCHUN) were added to 1,500 g of distilled water and stirred well at room temperature for 2 hours. After preparing a solution containing manganese / iron in a molar ratio of 1.0 / 2.0, a ferrite metal oxide catalyst was prepared in the same manner as in Example 1. The characteristics of the prepared catalyst are shown in Table 1 below.

Comparative Examples 1 and 2: Preparation of zinc-iron and magnesium-iron ferrite metal oxide catalysts using coprecipitation method

A zinc-iron ferrite metal oxide catalyst was prepared using a coprecipitation method based on the process diagram shown in FIG. 1.

205.98 g of iron nitrate (Fe (NO ₃ ) ₃ · 9H ₂ O, SAMCHUN, 98%) and 75.98 g of zinc nitrate (Zn (NO ₃ ) ₂ · 6H ₂ O, SAMCHUN, 98%) were added to 500 ml of distilled water. The solution was sufficiently stirred to melt well at to prepare a solution containing zinc / iron at 1.0 / 2.0 molar ratio. Thereafter, 4N sodium hydroxide aqueous solution was added to the zinc-iron mixed aqueous solution until the pH was 9.0, and stirred to prepare a coprecipitation solution of Zn (OH) ₂ -Fe (OH) ₃ . The coprecipitation solution was hydrothermally reacted at room temperature for 3 hours, at 60 ° C. for 6 hours, and at 90 ° C. for 12 hours. The co-precipitated metal oxide was sufficiently filtered with Buchner funnel and vacuum filter, dried with distilled water for 24 hours at 120 ° C., and heat-treated at 650 ° C. for 4 hours to prepare a zinc-iron ferrite metal oxide catalyst. It was.

A magnesium-iron metal oxide catalyst was also prepared in the same manner as in Comparative Example 1, except that the coprecipitation solution was 205.98 g of iron nitrate (Fe (NO ₃ ) ₃ · 9H ₂ O, SAMCHUN, 98%) and magnesium nitrate (Mg (NO ₃ )). ₂ · 6H ₂ O, SAMCHUN, 98%) 91.1 g was added to 500 ml of distilled water, and the mixture was sufficiently stirred at room temperature to prepare a solution containing magnesium / iron in a molar ratio of 1.0 / 2.0. The characteristics of the catalyst are shown in Table 1 below.

division Mole ratio Remarks Zn Mg Mn Fe Example 1 1.0 - - 2.0 Spray pyrolysis Example 2 - 1.0 - 2.0 Spray pyrolysis Example 3 - - 1.0 2.0 Spray pyrolysis Comparative Example 1 1.0 - - 2.0 Copyspace Comparative Example 2 - 1.0 - 2.0 Copyspace

Examples 4-5: Preparation of magnesium-iron ferrite metal oxide catalysts having different water concentrations

In the same manner as in Example 2, but by adjusting the water concentration to prepare a magnesium-iron ferrite metal oxide catalyst having a different concentration of the precursor. The composition ratio is shown in Table 2 below.

division Precursor concentration (% by weight) Iron precursor amount (g) Magnesium Amount (g) Water quantity (g) Example 4 31.0 1017.1 324.1 3,000 Example 2 47.2 1017.1 324.1 1,500 Example 5 64.1 1017.1 324.1 750

Examples 6 to 8: Preparation of magnesium-iron ferrite metal oxide catalysts having different solution input rates

In the same manner as in Example 2, a magnesium-iron ferrite metal oxide catalyst was prepared by adjusting the feed rate of the catalyst mixture solution. Composition ratios and catalyst mixed solution input rates are shown in Table 3 below.

division Catalyst Mixed Solution Input (L / h) Iron precursor amount (g) Magnesium Amount (g) Water quantity (g) Example 2 0.75 1017.1 324.1 1,500 Example 6 0.50 1017.1 324.1 1,500 Example 7 1.00 1017.1 324.1 1,500

Test Example 1: X-ray diffraction analysis (XRD) test of the prepared ferrite metal oxide catalyst

In order to confirm the crystal structure of the prepared catalyst was analyzed by an X-ray diffractometer (Siemens D-5005, Cukα = 1.5418 Å) using Ni-filter at 40 kV and 40 mA conditions, the analysis results are shown in Figure 2, Same as 3. 2 and 3, the crystal structure of the ferrite metal oxide catalyst was slightly different depending on the type of transition metal regardless of the preparation method. The zinc-iron and magnesium-iron ferrite catalysts of Examples 1 and 2 and Comparative Examples 1 and 2 were mostly spinel structures [MgFe ₂ O ₄ , JCPDS Card # 73-1270, ZnFe ₂ O ₄ , JCPDS Card # 65-3111 ], α -Fe ₂ O ₃ crystal structure [JCPDS Card # 33-0664] was present in the mixture it is. In the manganese-iron ferrite catalyst of Example 3, the FeMnO ₃ crystal structure was mostly, and the spinel structure and the α- Fe ₂ O ₃ crystal structure were partially mixed.

Test Example 2: Characterization of the Ferrite Metal Oxide Catalyst (Surface Area)

The surface area and pore volume of the catalyst prepared in Examples and Comparative Examples were measured using a volumetric nitrogen adsorption apparatus (Mirae SI, NanoPorisity-XQ), and then the surface area and pore volume were calculated using the BET equation. 4 is shown.

division Surface area (m ² / g) Pore volume (cm ³ / g) Example 1 30 0.21 Example 2 54 0.51 Example 3 59 0.47 Comparative Example 1 11 0.09 Comparative Example 2 29 0.20

Test Example 3 Characterization of the Ferrite Metal Oxide Catalyst (Shape)

Particle sizes and shapes of the catalysts prepared in Examples and Comparative Examples were measured using a scanning electron microscope (SEM, JEOL, JSM-7500F) and are shown in FIGS. 4 and 5. The catalysts of Examples 1 to 3 prepared by spray pyrolysis were spherical in shape and uniform in size to 10 to 50 μm.

Experimental Example 1: n -butene oxidative dehydrogenation reaction experiment

The catalyst prepared in Example and Comparative Example was charged to a quartz reactor at a space velocity (GHSV) of 400 h ⁻¹ , and activated at 400 ° C. while flowing air. 1,3-butadiene was subjected to oxidative dehydrogenation using a mixed gas having a mixing ratio of n -butene: air: steam at 400 ° C. at 10 vol%: 40 vol%: 50 vol% by using a mass flow controller. Was prepared. The reactor was designed to supply steam to the reactant using an initial micro metering pump, but to set a preheating section to vaporize the steam before being injected into the fixed bed reactor and to be injected into the reactor together with other reactants.

The catalytic activity was analyzed by sending the product of the oxidative dehydrogenation reaction to a gas chromatograph equipped with a thermal conductivity detector and a flame ion detector from 10 minutes after the reactant passed through the catalyst bed. The conversion of n -butene, 1,3-butadiene selectivity, and 1,3-butadiene yield are shown in Table 6 below. n -butene conversion, 1,3-butadiene selectivity, and 1,3-butadiene yield were calculated using Equations 1 to 3, respectively.

Equation 1: n -butene conversion

Equation 2: 1,3-butadiene selectivity

Equation 3: 1,3-butadiene yield

The composition of the C ₄ mixture used as a reactant is shown in Table 5 below.

Furtherance weight % C ₁ C ₃ 0.4 iso -butane 1.2 n -butane 23.3 1-butene 40.9 trans -2-butene 23.3 cis -2-butene 10.9 Sum 100

The n -butene oxidative dehydrogenation reaction results of the ferrite metal oxide catalysts of Examples 1 and 2 and Comparative Examples 1 and 2 are shown in Table 6 below.

division Conversion Rate
(%) 1,3-butadiene selectivity
(%) 1,3-butadiene yield
(%) Example 1 85.5 75.4 64.5 Example 2 84.7 77.9 65.9 Comparative Example 1 70.3 77.7 54.8 Comparative Example 2 78.0 70.3 55.5 [ n -butene oxidative dehydrogenation reaction condition]
Reaction temperature: 400 ℃
Response time: 7 h
Space Speed: 400 h ^-1
Reactant content (% by volume): n -butene / air / steam-10/40/50

After 7 hours of reaction time, the oxidative dehydrogenation product contains not only 1,3-butadiene but also carbon dioxide produced by complete oxidation and by-products of C ₁ to C ₃ by decomposition reaction. As shown in Table 6, the ferrite metal oxide catalyst of the example prepared by the spray pyrolysis method of the present invention has a slightly lower selectivity of 1,3-butadiene than the catalyst prepared by the conventional co-precipitation method (comparative example). The yield of 3-butadiene was 64.5% and 65.9%, which was about 10% higher.

Experimental Example 2 n -butene oxidative dehydrogenation reaction (reaction condition change)

Using the magnesium-iron ferrite metal oxide catalyst prepared in Example 2, and carried out by the experimental method of Experimental Example 1, in order to select the optimum reaction conditions, the space velocity is 250 h ^-1 , the reaction temperature is 370 ℃ , The composition of the reaction was changed to n -butene: air: steam mixing ratio of 8.6% by volume: 30.4% by volume: 61% by volume is shown in Table 7 below.

division Conversion Rate (%) Selectivity of 1,3-butadiene (%) 1,3-butadiene yield (%) Experimental Example 2
(Example 2) 86.0 81.6 70.2 Experimental Example 1
(Example 2) 84.7 77.8 65.9

Experimental Example 3 Results of n -butene Oxidative Dehydrogenation of Magnesium-Fe Ferrite Metal Oxide Catalysts of Examples 4 to 5

Using the magnesium-iron ferrite metal oxide catalyst prepared in Examples 4 to 5, and the reaction results by the experimental method of Experimental Example 2 are shown in Table 8.

division Precursor concentration
(weight%) Conversion Rate
(%) 1,3-butadiene
Selectivity
(%) 1,3-butadiene
yield
(%) Example 4 31.0 85.3 85.7 73.1 Example 2 47.2 86.0 81.6 70.2 Example 5 64.1 88.9 82.2 73.1 [ n -butene oxidative dehydrogenation reaction condition]
Reaction temperature: 370 ℃
Response time: 7 h
Space Speed: 250 h ^-1
Reactant content (% by volume): n -butene / air / steam-8.6 / 30.4 / 61.0

Experimental Example 4 Results of n -butene Oxidative Dehydrogenation of Magnesium-Fe Ferrite Metal Oxide Catalysts of Examples 6 to 7

Using the magnesium-iron ferrite metal oxide catalyst prepared in Examples 6 to 7, the reaction results of the experimental method of Experimental Example 2 are shown in Table 9 below.

division Solution input speed
(L / h) Conversion Rate
(%) 1,3-butadiene
Selectivity (%) 1,3-butadiene
yield(%) Example 6 0.50 88.4 82.1 72.6 Example 2 0.75 86.0 81.6 70.2 Example 7 1.0 87.2 81.6 71.2 [ n -butene oxidative dehydrogenation reaction condition]
Reaction temperature: 370 ℃
Response time: 7 h
Space Speed: 250 h ^-1
Reactant content (% by volume): n -butene / air / steam-8.6 / 30.4 / 61.0

Through the above Examples, Comparative Examples, Test Examples and Experimental Examples, the ferrite metal oxide catalyst prepared by the spray pyrolysis method of the present invention has a higher 1,3-butadiene selectivity and yield than the catalyst prepared by the conventional coprecipitation method. It was confirmed to be an excellent catalyst.

In addition, the metal oxide catalyst prepared by the spray pyrolysis method of the present invention has a simpler manufacturing method than the existing coprecipitation method, is economical because there is no additional treatment process, and it is easy to secure catalyst reproducibility, thereby stably producing 1,3-butadiene. It is expected that a single process can be secured.

Ferrite metal oxide catalysts prepared according to the invention are used for the preparation of 1,3-butadiene.

Claims (8)

The molar ratio of magnesium and iron is 1; A first step of dissolving the nitrate precursor of magnesium and the nitrate precursor of iron in distilled water so as to be 1.8 to 2.2;
A second step of forming a catalyst powder by thermally decomposing the mixed solution of the first step at a temperature of 650 to 750 ° C. while spraying the mixed solution of the first step into a high temperature reactor using air of 2 to 4 atm by a gas spray method
Method for producing a ferrite metal oxide catalyst comprising a.
delete The method of claim 1, wherein the temperature of the solution is maintained at 15 to 60 ° C. when the mixed solution is prepared in the first step.
Prepared according to claim 1, the mixed solution of the nitrate precursor of magnesium and the nitrate precursor of iron is composed of a spray pyrolysis powder phase so that the molar ratio of magnesium and iron is 1: 1.8 to 2.2, the surface area is 30 ~ 100 A ferrite metal oxide catalyst, characterized in that m 2 / g and pore volume is 0.21 to 1 cm 3 / g.
A method for producing 1,3-butadiene prepared by oxidative dehydrogenation of n -butene in the presence of a ferrite metal oxide catalyst according to claim 4.
The method of claim 5, wherein the reactant of the oxidative dehydrogenation reaction includes n -butene, air and steam, and the mixing ratio of the reactants is n -butene: air: steam = 4 to 12% by volume: 15 to 45 Volume%: 1,3-butadiene production method characterized in that 45 to 80% by volume.
The method for preparing 1,3-butadiene according to claim 6, wherein the reactant is injected at a space velocity of 150 to 700 h ⁻¹ based on n -butene in the oxidative dehydrogenation reaction.
The method of claim 6, wherein the oxidative dehydrogenation reaction is performed at a temperature in a range of 300 to 500 ° C. 7.

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