KR101937872B1 - Catalysts for propane ammoxidation, preparation method thereof and method for producing acrylonitrile using the same - Google Patents

Abstract

The catalyst developed by the present invention is superior in thermal stability to a catalyst having a bulk form supported on alumina and has an advantage in economic efficiency because it is made of an element having a relatively low price. It also has the potential to be easily applied because it does not have a specific crystal structure.
Also, through the pretreatment process described in the present invention, the catalyst of the same component can exhibit higher reactivity under the same reaction conditions. Also, the side reaction of the product can be reduced.
In addition, the catalyst developed by the present invention shows a high yield at a higher space velocity than the optimum space velocity of other catalysts used in the propane ammoxidation reaction. Accordingly, an effective and economical process can be designed because a large amount of product can be produced per unit time.

Description

TECHNICAL FIELD The present invention relates to a catalyst for propane ammoxidation reaction, a process for preparing the same, and a process for producing acrylonitrile using the same,

The present invention relates to a catalyst for propane ammonia oxidation reaction, a process for producing the same, and a process for preparing acrylonitrile using the same, and more particularly, to a process for producing propane ammoxidation The present invention relates to a process for preparing a catalyst for reaction, and a process for producing acrylonitrile using the catalyst.

Propane is a basic alkane composed of three carbons, one of the materials that is currently mostly used as an energy source due to its low reactivity despite its industrial value. However, as the development of shale gas mainly in North America has been activated recently, it is expected that the supply of low-priced propane will increase, and attempts are being made to produce products using propane as a direct raw material. A representative example thereof is acrylonitrile. Acrylonitrile is one of the high value-added products that can be produced using propane, and is used for the production of industrial adhesives, fibers and polymer resins, and in particular polyacrylonitrile, an organic precursor material of carbon fibers.

The process of using the alkane as a direct raw material including the propane which has been attempted so far is mostly low in activity due to the low reactivity of the alkane, and thus there are few cases of commercialization successfully. However, recent developments of catalysts using alkane have shown great promise as catalysts for producing desired products with high selectivity at the same time showing high reactivity to stable structure of alkane. A typical example is the production of maleic anhydride using butane. The present reaction using a vanadium-phosphorus oxide catalyst system showed high activity and selectivity using low-reactivity butane, and successfully commercialized and maintained a stable yield over a long period of time (Non-Patent Document 1).

Representative reactions for producing acrylonitrile can be classified into Sohio process using propylene and process using propane. The Sohio process using propylene is a representative example of a successfully developed partial oxidation process. Since the introduction of the Sohio process in the early 1960s, the conversion rate of the bismuth molybdenum series catalyst was about 95% and the selectivity of acrylonitrile 80% or more (Non-Patent Document 2). The reaction using propane proceeds in the order of finally producing acrylonitrile while the allyl intermediate formed by desorbing hydrogen of the propane reacts with nitrogen adsorbed species adsorbed on the catalyst surface (Non-Patent Document 3).

Since the process using propane is very low in reactivity than propylene, it is necessary to develop a catalyst having excellent activity and resistance to high temperature long contact time. At present, the process using propylene is operated at a high yield, and therefore, a propane process catalyst having a low yield of propane and a high yield is required to replace it. In spite of the difficulty of reaction, propane is more competitive than propylene, and shale gas is developed and considered as a future-oriented raw material. Therefore, it is being tried by companies such as BP, Mitsubishi and Asahi in Japan, Has succeeded in commercializing the technology through the ammoxidation reaction of acrylonitrile to produce acrylonitrile.

The process using propane proceeds largely in the order of the dehydrogenation reaction of propane and the ammonia oxidation reaction of the produced propylene. The less reactive propane adsorbs first on the catalyst surface and is oxidized and activated by the lattice oxygen. Propane in which hydrogen is desorbed on the surface of the catalyst is activated again as an intermediate in allyl form at the base point of the catalyst and finally acrylonitrile is produced by the ammonia species on the surface of the catalyst (Non-Patent Document 4).

Up to now, many catalysts including heteropoly acid (Patent Document 1) and metal complex oxides have been applied to the ammonia addition oxidation reaction of propane. The most widely used catalyst for the propane ammoxidation reaction is a catalyst having vanadium and antimony (Patent Document 2), showing a selectivity of about 60%. Recently, in addition to vanadium and antimony-based catalysts, high-activity multicomponent oxide catalysts such as Mo-V-Te-Nb-O have been developed and attracted much attention. The Mo-V-Te-Nb-O catalyst system has a specific crystal structure of M1 and M2 directly related to the reaction. In the case of the M1 structure, the M2 structure is known to be more effective for the ammonia addition oxidation reaction of propylene in the ammonia addition oxidation reaction of propane (Patent Document 3). In the case of the above-mentioned catalysts, it is known that some of the reactions other than the ammoxidation reaction of propane also exhibit high activity, and many studies have been conducted. However, it has some problems such as evaporation over time due to the volatility of the tellurium component (Non-Patent Document 5). Accordingly, it is required to develop a new propane dehydrogenation process which solves the above problem and reduces the production cost.

On the other hand, researches for changing the state of the catalyst through the preparation of the catalyst and the pretreatment, which are not the components of the catalyst, are also receiving much attention. Especially, the catalysts for propane ammoxidation reaction are known to show a large yield difference depending on the preparation method and the pretreatment process. In this connection, studies have been made to improve the activity of the catalyst through such a method as using a basic solution (Patent Document 4). The most prominent example of the pretreatment process affecting the activity of the catalyst is the reaction to produce maleic anhydride using butane. The vanadium-phosphorus catalyst in this reaction is known to exhibit stable activity after pretreatment for about 100 hours in the reactant composition (Non-Patent Document 6).

As stated, propylene was preferred as a feedstock rather than propane in terms of economy in the process up to now, but it is expected that considerable economic benefits will be gained from the process using propane due to the lowering of propane and the development of catalysts. However, the present propane process has not been successfully commercialized due to some problems.

Accordingly, the present inventors have designed and manufactured a catalyst system capable of economically and efficiently producing acrylonitrile through the reaction of producing acrylonitrile using propane. The aim of the present invention is to find a more efficient reaction system than the conventional reaction system by selectively producing acrylonitrile through the propane ammoxidation reaction using the catalyst.

Therefore, the inventors of the present invention have found that when a catalyst for propane ammoxidation reaction, in which a metal oxide containing molybdenum, vanadium and phosphorus is supported on an alumina carrier, acrylonitrile can be produced using the catalyst, .

Patent Document 1: Korean Patent Laid-Open Publication No. 10-2005-0043737 Patent Document 2: Korean Patent Publication No. 10-0443453 Patent Document 3. US Patent No. 5422328 Patent Document 4: Korean Patent Publication No. 10-0373895

Non-Patent Document 1. Volta, J.C. R. Acad. Sci. Ser: IIC, Chim., 3, (2000): 717-723 Non-patent document 2. Grasselli, Robert K., et al. Top. Catal. 23, (2003): 5-22. Non-patent document 3. Belgacem, J., J. Kress, and J. A. Osborn. J. Mol. Catal., 86, (1994): 267-285. Non-patent document 4. Grasselli, Robert K., et al. Catal. Today., 91, (2004): 251-258. Non-Patent Document 5. Grasselli, R. K. JD Burrington in Handbook of Heterogeneous Catalysis, 7, (2008): 3479. Non-patent document 6. Hutchings, Graham J., et al. J. Catal., 197, (2001): 232-235.

SUMMARY OF THE INVENTION The present invention has been accomplished in view of the above problems, and an object of the present invention is to provide a catalyst for propane ammonia oxidation reaction in which a metal oxide containing molybdenum, vanadium and phosphorus is supported on an alumina carrier, And to provide a method for producing ronitril.

In order to achieve the above object, the present invention provides a catalyst for propane ammoxidation reaction comprising (i) alumina, and (ii) metal complex oxides of molybdenum, vanadium and phosphorus supported on the alumina.

A weight ratio of molybdenum to alumina is 1-30 wt%; The weight ratio of vanadium is 0.1-10 wt%; The weight ratio of phosphorus may be 0.1-10 wt%;

The catalyst may have a BET specific surface area of 150-250 m ² / g and a pore size of 2-50 nm.

The present invention also provides a process for producing a precursor solution, comprising: (a) mixing a molybdenum precursor, a vanadium precursor, a reducing agent and a solvent to obtain a precursor solution; (b) mixing the precursor solution, phosphorus precursor and alumina precursor to prepare a mixed solution; (c) drying the mixed solution to obtain a solid; And (d) heat treating the solid material in an inert gas atmosphere to obtain a catalyst in which molybdenum, vanadium and phosphorus metal complex oxides are supported on alumina.

The weight ratio of the aluminum precursor and the solvent may be 1: 1-30.

The molar ratio of the sum of molybdenum to vanadium and the reducing agent may be 1: 0.1-5.

The drying may be carried out at a temperature of 50-200 占 폚 and a reduced pressure for 1-60 hours.

The inert gas atmosphere may be an atmosphere in which an inert gas selected from argon, nitrogen, neon, helium, and a mixture of two or more of these gases is supplied.

The heat treatment may be performed at 200-1200 ° C for 1-24 hours.

The heat treatment may be performed under an atmosphere further including a reducing gas.

The present invention also relates to a process for the production of propane by reacting a mixed gas of propane, oxygen, ammonia and nitrogen at a temperature of 300-800 ° C and a total space velocity of propane, oxygen and ammonia of 100-20000 h ^-1 . ≪ / RTI > In another aspect, the present invention provides a process for producing acrylonitrile.

The method for preparing acrylonitrile may further include a step of pretreating the catalyst for propanols oxidation reaction according to the present invention at 100-600 ° C for 1-10 hours under a mixed atmosphere of an inert gas and a reducing gas .

The volume ratio of propane, oxygen, ammonia, and nitrogen may be 1: 0.5-20: 0.1-10: 1-50.

According to the present invention, it is possible to produce a catalyst for propane ammoxidation reaction in which a metal oxide containing molybdenum, vanadium and phosphorus is supported on an alumina support, and thereby acrylonitrile can be produced with high yield.

1 is a nitrogen adsorption / desorption isotherm graph of 8.1 Mo-1.9 V-XP / Al (X = 0, 0.6, 1.2, 2.3, 3.5 weight%) catalysts prepared from Examples 1 to 5 of the present invention.
2 shows X-ray diffraction (XRD) characteristics of the 8.1 Mo-1.9 V-XP / Al (X = 0, 0.6, 1.2, 2.3, 3.5 wt%) catalyst prepared from Examples 1-5 of the present invention Graph.
3 is a graph showing the reaction activity results of 8.1 Mo-1.9 V-XP / Al (X = 0, 0.6, 1.2, 2.3, 3.5 weight%) catalyst prepared from Examples 1 to 5 of the present invention.
4 is a graph showing the tendency of the reaction activity tendency after the reaction of 8.1 Mo-1.9 V-XP / Al (X = 0, 0.6, 1.2, 2.3, 3.5 weight%) catalyst prepared from Examples 1 to 5 of the present invention for 6 hours to be.

In the following, various aspects and various embodiments of the present invention will be described in more detail.

The present invention provides a catalyst for propane ammoxidation reaction comprising (i) alumina, and (ii) metal complex oxides of molybdenum, vanadium and phosphorus supported on the alumina.

A complex oxide catalyst comprising molybdenum (Mo), vanadium (V), tellurium (Te) and niobium (Nb) is known as a conventional catalyst for propaniloxidation reaction. Such a complex oxide catalyst is known as orthorhombic _{) Mo 7 .8 V 1 .2 NbTe} 0 .94 O 28 .9 (Pba2: a = 21.1337 Å; b = 26.6440 Å; c = 4.01415 Å; z = 4) (M1) and similar hexagonal crystal (pseudo-hexagonal ) Having a specific crystal structure of (Mo) _4.6 7V _1.33 Te _1.82 O _19.82 (Pmm 2: a = 12.6294 Å; b = 7.29156 Å; c = 4.02010 Å; z = Have been reported. However, there is a problem that the complex oxide catalyst causes deterioration of the catalyst due to volatilization of the tellurium from the catalyst during the production of acrylonitrile, and when the tellurium or niobium among the components of the catalyst is excluded, it has no specific crystal structure of M1 and M2 And low reactivity. On the other hand, the catalyst for propanetriol oxidation reaction according to the present invention is a simple metal oxide catalyst having no specific crystal structure, and includes P (phosphorus) except for tellurium and niobium components, thereby exhibiting high activity for propane ammoxidation reaction And it was confirmed that there was an effect of showing a high yield of acrylonitrile even at a space velocity higher than the optimal space velocity of conventional catalysts.

X-ray diffraction analysis of the catalyst for propane ammoxidation reaction according to the present invention showed effective peaks in the range of 2? = 23 to 38, 2? = 34 to 40 and 2? = 52 to 55 And molybdenum oxide peak in which a large amount of molybdenum was aggregated was observed through this, and the effective peak was shown in the range of 2? = 43 ° to 48 ° and 2θ = 64 ° to 70 °, whereby the characteristic peak on gamma alumina Respectively. In addition, it was confirmed that vanadium and phosphorus-related characteristic peaks did not appear.

The weight ratio of molybdenum to alumina is 1-30 wt%, preferably 15-25 wt%; The weight ratio of vanadium is 0.1-10 wt%, preferably 1-5 wt%; If the weight ratio of the components constituting the catalyst is less than the lower limit value, the number of active sites of the catalyst may be decreased. In this case, The oxidation activity is reduced and the conversion of propane is reduced. When it is contained in excess of the upper limit value, the active sites of the catalyst are dense and the sintering phenomenon is caused to result in the increase of the effective active sites or the pores of the carrier. There is a problem that the performance is deteriorated.

The catalyst may have a BET specific surface area of 150-250 m ² / g, preferably 180-200 m ² / g, and a pore size of 2-50 nm, preferably 6.0-8.0 nm. The catalyst for the propane ammoxidation reaction according to the present invention shows typical characteristics of a mesoporous material and is effective in increasing the catalytic activity by increasing the adsorption amount of the catalyst while increasing the specific surface area of the particles.

The present invention also provides a process for producing a precursor solution, comprising: (a) mixing a molybdenum precursor, a vanadium precursor, a reducing agent and a solvent to obtain a precursor solution; (b) mixing the precursor solution, phosphorus precursor and alumina precursor to prepare a mixed solution; (c) drying the mixed solution to obtain a solid; And (d) heat treating the solid material in an inert gas atmosphere to obtain a catalyst in which molybdenum, vanadium and phosphorus metal complex oxides are supported on alumina.

The molybdenum precursor may be at least one selected from the group consisting of ammonium heptamolybdate, molybdenum oxide, molybdenum chloride, molybdenum oxychloride, molybdenum acetylacetonate, molybdenum oxytriethoxide, phosphomolybdic acid and silicomolybdic acid , But not limited thereto, any of the commonly used precursors can be used, and preferably ammonium heptamolybdate can be used.

The vanadium precursor may be at least one selected from ammonium metavanadate, vanadyl sulfate, vanadium oxide, vanadium chloride, vanadium oxychloride, vanadium oxytriethoxide, vanadium acetylacetonate and vanadyl acetylacetonate, Any of the precursors conventionally used may be used without limitation, and ammonium metavanadate can be preferably used.

The phosphorus precursor may be at least one selected from the group consisting of phosphorous acid, phosphonic acid, phosphinic acid, ammonium hydrogenphosphate, phosphorous halide, ester phosphorous and phosphoric acid, but not limited thereto, any of the commonly used precursors can be used, Phosphoric acid can be used.

Wherein the alumina precursor is selected from the group consisting of aluminum oxide, aluminum hydroxide, aluminum nitrate, aluminum chloride, aluminum acetylacetonate, aluminum butoxide, aluminum ethoxide, aluminum fluoride, aluminum iodide, aluminum isopropoxide, And aluminum phosphate. However, it is not limited thereto, and any conventionally used precursor may be used, and aluminum oxide may be preferably used.

The reducing agent may be at least one selected from oxalic acid, tartaric acid, malonic acid, succinic acid, and phthalic acid, but is not limited thereto. Preferably, oxalic acid can be used.

The solvent may be selected from the group consisting of water, methanol, ethanol, 1-propanol, 2-propanol, butanol, 1-heptanol, 4-methyl-1-hexanol, Diol, glycerol, deuterene glycol, and trimethylene glycol, but is not limited thereto. Preferably, water can be used.

The weight ratio of the aluminum precursor and the solvent may be 1: 1-30. When the solvent is less than the lower limit of the weight ratio, the molybdenum precursor, the vanadium precursor, the phosphorus precursor, and the aluminum precursor are not properly mixed, The amount to be supported on the alumina may be small, preferably 1: 5.

The molar ratio of the molybdenum and vanadium and the reducing agent may be 1: 0.1-5. When the reducing agent is less than the lower limit of the molar ratio, the molybdenum precursor and the vanadium precursor are not properly reduced to metal, There is a problem in that it is not economical to use a large amount of reducing agent unnecessarily. Preferably 1: 1-2.

The drying may be performed at a temperature of 50-200 ° C and a reduced pressure for 1 to 60 hours. The drying may be performed by a drying method selected from a rotary evaporator drying method, a spray drying method, and a evaporative drying method, but is not limited thereto.

As a specific example, if carried out by rotary evaporator drying, it can be carried out by stirring for 1 to 60 hours at a temperature of 50 to 200 DEG C, preferably at a temperature of 60 to 100 DEG C for 1 to 3 hours ≪ / RTI > As the heating source for drying, it is preferable to use water heated by steam, an electric heater, or oil.

It can also be carried out by spraying and heating the mixture solution or slurry when carried out by spray drying. The spray drying can be carried out by centrifugal separation, the advective nozzle method or the high-pressure nozzle method. As the heating source for drying, it is preferable to use steam or air heated by an electric heater or the like. It is also preferable that the temperature of the spray dryer inlet is 150 to 300 ° C.

It can also be carried out by heating the solution in a beaker when carried out by evaporative drying. The heating time may vary depending on the amount of the mixture solution or slurry, and the preferred heating time is 5 minutes to 24 hours, and may be carried out at a temperature of 30-150 ° C. And more preferably at 60-85 DEG C for 30 minutes to 5 hours.

The inert gas atmosphere may be an atmosphere in which an inert gas selected from argon, nitrogen, neon, helium, and a mixture of two or more of these gases is supplied.

The heat treatment may be performed at 200 to 1200 ° C, preferably 500 to 700 ° C, for 1 to 24 hours, preferably 1 to 8 hours, and may be performed under an atmosphere further containing a reducing gas. It is preferable that ammonia is used as the reducing gas, and the oxygen concentration of the above-mentioned gas is preferably 1000 ppm or less.

Further, the heat treatment may be performed in two stages. As a specific example, the dried solid (catalyst precursor) is first heat-treated at 200-350 ° C and 1-6 hours under oxygen-containing air conditions, and then the heat-treated catalyst is heated at 500-700 ° C And a time of 1 to 10 hours.

The present invention also relates to a process for the production of propane by reacting a mixed gas of propane, oxygen, ammonia and nitrogen at a temperature of 300-800 DEG C and a total space velocity of propane, oxygen and ammonia of 100-20000 h < ^{-1 &} gt ;.

When the reactant is fed to the reactor in the ammoxidation reaction of propane, the amount of the reactant to be injected can be controlled by using a mass flow rate controller. The amount of the reactant to be injected is preferably 100 to 100 g / hr (Gas Hourly Space Velocity) -20,000 h < ^{-1 &} gt ;, and more preferably 2,000-7,000 h < ^{-1 &} gt ;. If the space velocity is less than 100 h ^-1, coking may occur as a by-product while the reaction of the catalyst occurs in a limited region, and hot spots may be generated due to heat released during the reaction. h < ^{-1 &} gt ;, the catalytic action may not sufficiently take place while the reactant passes through the catalyst layer.

The method for preparing acrylonitrile may further include a step of pretreating the catalyst for propanols oxidation reaction according to the present invention at 100-600 DEG C for 1-10 hours under a mixed atmosphere of an inert gas and a reducing gas By activating the catalyst through the pretreatment process, the catalyst of the same component can exhibit higher reactivity under the same reaction conditions, and the side reaction of the product can be reduced. If the reaction temperature is lower than 100 ° C, the propane is not sufficiently activated. If the reaction temperature is higher than 600 ° C, the decomposition reaction of propane may occur. . Further, it is more preferable that the reaction is carried out at 250-500 DEG C for 1-3 hours at which the structural change of the catalyst is easily occurred. The reducing gas affects the structure and oxidation state of the catalyst at a temperature higher than a certain level, thereby making it possible to make favorable conditions for the ammoxidation reaction of propane. As a specific example, it is preferred that the pretreatment comprises ammonia gas, which is a transporting nitrogen and a reducing gas.

The volume ratio of propane, oxygen, ammonia and nitrogen may be in the range of 1: 0.5-20: 0.1-10: 1-50, preferably 1: 2-4: 0.5-2: 5-15, more preferably 1: 1.5: 12.

When the ratio of oxygen is out of the above range, the complete oxidation reaction is excessively generated or the activity of the catalyst is lowered. When the ratio of ammonia is out of the above-mentioned range, the activity of the catalyst is also decreased and the selectivity of acrylonitrile . And the process stability may be problematic.

Hereinafter, production examples and embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

Examples 1 to 5: Preparation of 18.1Mo-1.9V-XP / Al catalyst

1.66 g of ammonium heptamolybdate and 0.22 g of ammonium metavanadate were dissolved in 25 g of distilled water and 2.85 g of oxalic acid was mixed at the same time to prepare a precursor solution. The precursor solution was stirred at 85 ° C for 1 hour and then phosphoric acid was added thereto so that the content of phosphorus was 0, 0.6, 1.2, 2.3 and 3.5% by weight based on the carrier. Then, 5 g of commercial alumina was added thereto, The mixture was stirred at a temperature of 85 DEG C for 3 hours and mixed. Thereafter, the mixture was injected into a rotary evaporator, and at the same time, it was dried using a hot water bath at 85 캜 under reduced pressure by an aspirator. Then, the dried catalyst was finally subjected to a heat treatment for 2 hours while maintaining the temperature at 550 ° C in a tubular fired apparatus of a nitrogen atmosphere to obtain a catalyst of the final form, and the thus-prepared catalyst was calcined at 18.1Mo-1.9V-XP / Al. At this time, the content of molybdenum was 18.1 wt%, the content of vanadium was 1.9 wt%, the amount of phosphorus was X (wt%), and the contents of phosphorus were in Examples 1 to 5, respectively.

Comparative Examples 1 to 4: Preparation of 18.1Mo-1.9V-0.6P-XM / Al catalyst

A catalyst was prepared in the same manner as in Example 1 except that one of Te, Sb, Bi and Nb was used as an additional metal (M).

An additional metal precursor (telluric acid, antimony oxide, bismuth nitrate, ammonium niobium oxalate) was added to the precursor solution of Example 1 so that the molar ratio of vanadium base metal was 0.5. Then, the catalyst was dried and heat-treated in the same manner as in Example 1 to prepare a molybdenum-vanadium-phosphorus-addition metal M (Te, Sb, Bi, Nb) catalyst supported on alumina. Each prepared catalyst was named 18.1Mo-1.9V-0.6P-XM / Al. At this time, the content of molybdenum was 18.1 wt%, the content of vanadium was 1.9 wt%, the amount of phosphorus was 0.6 wt%, the content of additional metal (M) was expressed as X (wt% Nb in Comparative Examples 1 to 4, respectively.

Experimental Example 1: Characterization of 18.1Mo-1.9V-XP / Al Catalyst

1 is a nitrogen adsorption / desorption isotherm graph of 8.1 Mo-1.9 V-XP / Al (X = 0, 0.6, 1.2, 2.3, 3.5 weight%) catalysts prepared from Examples 1 to 5 of the present invention. As can be seen from FIG. 1, all of the catalysts produced exhibit an IV-type nitrogen adsorption / desorption isotherm, which is characteristic of typical mesoporous materials and exhibits a H2-type hysteresis loop. It can be seen that the catalysts are formed mainly of pores in the form of ink-bottles.

Table 1 below summarizes the results of nitrogen adsorption / desorption experiments of 18.1 Mo-1.9 V-XP / Al (X = 0, 0.6, 1.2, 2.3, 3.5 wt%) catalysts prepared from Examples 1 to 5 . The specific surface area of the catalyst prepared from Table 1 is about 180-200 m ² / g, and the average pore size is about 6.0-7.5 nm. Also, the pore volume tends to decrease as the amount of phosphorus loaded increases. As the amount of phosphorus increases, the volume of the pore decreases gradually.

catalyst Specific surface area (m ² / g) Pore volume (cm ³ / g) Pore size (nm) 18.1Mo-1.9V / Al 192 0.36 7.5 18.1 Mo-1.9 V-0.6 P / Al 193 0.36 7.4 18.1 Mo-1.9 V-1.2 P / Al 197 0.35 7.2 18.1 Mo-1.9 V-2.3 P / Al 187 0.32 6.8 18.1 Mo-1.9 V-3.5 P / Al 192 0.31 6.4

2 shows X-ray diffraction (XRD) characteristics of the 8.1 Mo-1.9 V-XP / Al (X = 0, 0.6, 1.2, 2.3, 3.5 wt%) catalyst prepared from Examples 1-5 of the present invention Graph. Referring to FIG. 2, all of the catalysts of Examples 1 to 5 showed characteristic peaks on gamma alumina, and molybdenum oxide peaks in which an excess amount of molybdenum clusters appeared. The peak related to vanadium or phosphorus was not observed and it was judged that vanadium and phosphorus were well dispersed therefrom.

Experimental Example 2: Propane ammoxidation reaction on 18.1Mo-1.9V-XP / Al catalyst

Acrylonitrile production reaction was carried out by the ammoxidation reaction of propane using 18.1 Mo-1.9 V-XP / Al (X = 0, 0.6, 1.2, 2.3, 3.5 weight%) catalyst prepared in Example 1 .

The ratio of the gas used in the propane ammoxidation reaction was set to be propane: oxygen: ammonia: nitrogen = 1: 3: 1.5: 12. The amount of the reactant was injected so that the gas hourly space velocity (GHSV) of propane, oxygen and ammonia was 5,000 h ^-1 . Prior to the ammonia oxidation reaction of propane, the catalyst (0.2 g) was charged in a quartz reactor to activate the catalyst, and then the temperature was raised to 480 ° C. at a rate of 5 ° C./min, and nitrogen and ammonia gas Respectively. After the reaction temperature was reached for sufficient pretreatment of the catalyst, it was maintained under a reducing gas atmosphere for 2 hours. Thereafter, propane gas and oxygen reacted through the catalyst layer to conduct a propane ammoxidation reaction. In this experimental example, conversion of propane, product selectivity, and yield of acrylonitrile were calculated by the following equations (1), (2) and (3), respectively.

[Equation 1]

&Quot; (2) "

&Quot; (3) "

3 is a graph showing the reaction activity results of 8.1 Mo-1.9 V-XP / Al (X = 0, 0.6, 1.2, 2.3, 3.5 weight%) catalyst prepared from Examples 1 to 5 of the present invention. It can be seen that the yield is constant in all the catalysts for 6 hours without significant change.

4 is a graph showing the reaction activity tendency of the 8.1 Mo-1.9 V-XP / Al (X = 0, 0.6, 1.2, 2.3, 3.5 weight%) catalyst prepared in Examples 1 to 5 of the present invention after 6 hours of reaction Fig. It was confirmed that the reaction yield increased and decreased with the addition of phosphorus, indicating that the addition of suitable phosphorus improved the conversion of propane and the selectivity of acrylonitrile while affecting the surface structure of the catalyst do. The results of the reaction of each catalyst after 6 hours of reaction are summarized in Table 2 below. The yields of the respective catalysts were 18.1Mo-1.9V-0.6P / Al> 18.1Mo-1.9V-1.2P / Al> 18.1Mo-1.9 V / Al> 18.1Mo-1.9V-2.3P / Al> 18.1Mo-1.9V-3.5P / Al.

catalyst Propane conversion (%) Acrylonitrile selectivity (%) Acrylonitrile
Yield (%) 18.1Mo-1.9V / Al 78.9 34.3 27.1 18.1 Mo-1.9 V-0.6 P / Al 81 36.4 29.5 18.1 Mo-1.9 V-1.2 P / Al 78 35.9 28.1 18.1 Mo-1.9 V-2.3 P / Al 57.7 29.6 17.1 18.1 Mo-1.9 V-3.5 P / Al 48.3 27.9 13.5

Experimental Example  3: untreated 18.1 Mo -1.9V- XP / Al  Propane on the catalyst Ammoxidation  reaction

The propane ammoxidation reaction was carried out without pretreatment with ammonia using 8.1 Mo-1.9 V-XP / Al (X = 0, 0.6, 1.2, 2.3, 3.5 wt%) catalyst prepared in Examples 1 to 5 of the present invention To prepare an acrylonitrile.

In the case of the ratio of the gas or the reaction condition, the same procedure as in Example 1 was carried out, and only the nitrogen was flowed without ammonia during the heating process. The results are shown in Table 3 below after 6 hours reaction of 18.1Mo-1.9V-XP / Al catalyst without pretreatment. As can be seen from the following Table 3, it can be seen that the propane conversion, acrylonitrile selectivity, and acrylonitrile yield are improved when the activated catalyst is used through the pretreatment process as compared to the non-activated catalyst.

catalyst Propane conversion (%) Acrylonitrile selectivity (%) Acrylonitrile
Yield (%) 18.1 Mo-1.9 V-0.6 P / Al (pretreatment) 81 36.4 29.5 18.1 Mo-1.9 V-0.6 P / Al
(No preprocessing) 73.6 33.6 24.7

Experimental Example 4: Propane ammoxidation reaction on 18.1Mo-1.9V-0.6P-XM / Al catalyst

(M = Te, Sb, Bi, Nb) catalyst prepared in Comparative Example 1 under the same conditions as Experimental Example 2, Ronitril production reaction was carried out. The metals added to this reaction were selected based on the elements that helped hydrogen desorption or structural stability. The activity of the catalyst when the additional metal is introduced is summarized in Table 4 below. As can be seen from the following Table 4, the catalyst comprising the metal complex oxide of molybdenum, vanadium and phosphorus according to the present invention has a higher propane conversion and higher catalytic activity than the catalyst containing further metals of tellurium, antimony, bismuth and niobium, The yield of nitrile can be confirmed.

catalyst Propane
Conversion Rate (%) Acrylonitrile selectivity (%) Yield of acrylonitrile (%) 18.1 Mo-1.9 V-0.6 P / Al 81 36.4 29.5 18.1 Mo-1.9 V-0.6 P-2.4 Te / Al 72.3 35.3 25.5 18.1 Mo-1.9 V-0.6 P-2.3 Sb / Al 63 34.8 21.9 18.1Mo-1.9V-0.6P-3.9Bi / Al 67.9 38.3 25.9 18.1Mo-1.9V-0.6P-1.7Nb / Al 75.7 35.8 27.1

Therefore, according to the present invention, it is possible to provide a catalyst for propane ammoxidation reaction in which a metal oxide containing molybdenum, vanadium and phosphorus is supported on an alumina support, and it is possible to provide acrylonitrile even under high space velocity conditions by pre- And can be produced at a high yield.

Claims (13)

A catalyst for propane ammoxidation reaction comprising (i) alumina, and (ii) a metal complex oxide of molybdenum, vanadium and phosphorus supported on the alumina,
Wherein the weight ratio of molybdenum to alumina is 1-30 wt%, the weight ratio of vanadium is 0.1-10 wt%, and the weight ratio of phosphorus is 0.1-2.0 wt%
Wherein the catalyst has no specific crystal structure. delete The method according to claim 1,
Wherein the catalyst has a BET specific surface area of 150-250 m ² / g and a pore size of 2-50 nm. (a) mixing a molybdenum precursor, a vanadium precursor, a reducing agent and a solvent to obtain a precursor solution;
(b) mixing the precursor solution, phosphorus precursor and alumina precursor to prepare a mixed solution;
(c) drying the mixed solution to obtain a solid; And
(d) heat treating the solid material in an inert gas atmosphere to obtain a catalyst in which a metal complex oxide of molybdenum, vanadium and phosphorus is supported on alumina, the method comprising the steps of:
Wherein the weight ratio of molybdenum to alumina is 1-30 wt%, the weight ratio of vanadium is 0.1-10 wt%, and the weight ratio of phosphorus is 0.1-2.0 wt%
Wherein the catalyst for propane ammoxidation reaction does not have a specific crystal structure. 5. The method of claim 4,
Wherein the weight ratio of the alumina precursor and the solvent is 1: 1-30. 5. The method of claim 4,
Wherein the molar ratio of the molybdenum to vanadium and the reducing agent is 1: 0.1-5. 5. The method of claim 4,
Wherein the drying is carried out at a temperature of 50-200 deg. C and a reduced pressure for 1-60 hours. 5. The method of claim 4,
Wherein the inert gas atmosphere is an atmosphere in which an inert gas selected from argon, nitrogen, neon, helium, and a mixture of two or more gases is supplied. 5. The method of claim 4,
Wherein the heat treatment is carried out at 200 to 1200 ° C for 1 to 24 hours. 5. The method of claim 4,
Wherein the heat treatment is performed in an atmosphere further containing a reducing gas. Wherein the mixed gas of propane, oxygen, ammonia and nitrogen is heated at a temperature of 300-800 DEG C and a total space velocity of the propane, oxygen and ammonia is 100-20000 h < ^-1 > in the presence of the catalyst for propane- And reacting the acrylonitrile with a solvent. 12. The method of claim 11,
A process for preparing acrylonitrile according to claim 1, further comprising the step of pre-treating the catalyst for the propane ammoxidation reaction in a mixed atmosphere of an inert gas and a reducing gas at 100-600 DEG C for 1-10 hours . 12. The method of claim 11,
Wherein the volume ratio of propane, oxygen, ammonia, and nitrogen is 1: 0.5-20: 0.1-10: 1-50.

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