KR101910966B1 - Method for preparing metal oxide catalyst and method for preparing acrylonitrile using the same - Google Patents

Abstract

The present invention relates to a process for producing a metal oxide catalyst and a process for producing acrylonitrile using the same, and more particularly, to a process for preparing a metal oxide catalyst for use in the ammoxidation reaction of propane, .
The metal oxide catalyst supported on the diluent according to the present invention has excellent thermal stability due to the introduction of a diluent, and has a high economic efficiency because it can achieve high performance even with a small amount of catalyst. In addition, active sites can be effectively distributed through diluents, greatly reducing side reactions and achieving higher catalyst productivity than when no diluent is used.
In addition, acrylonitrile can be easily prepared from propylene dianilpropane using the metal oxide catalyst, which can produce acrylonitrile directly from propane, thereby providing economical advantages and being able to actively cope with future market changes .

Description

METHOD FOR PREPARING METALLIC OXIDE CATALYST AND METHOD FOR PREPARING ACRYLONITRILE USING THE SAME,

The present invention relates to a process for producing a metal oxide catalyst and a process for producing acrylonitrile using the same, and more particularly, to a process for preparing a metal oxide catalyst for use in the ammoxidation reaction of propane, .

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 products that can be produced using propane, and is used for the production of industrial adhesives, fibers and polymer resins, and especially for the synthesis of 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 roughly divided into a propylene process and a sohio process using propane. First, the propylene process 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 is currently 95% and the selectivity of acrylonitrile is 80% (Non-Patent Document 2). In the reaction using propylene, the allyl intermediate formed by desorbing the hydrogen of propylene reacts with the nitrogen adsorbing species adsorbed on the catalyst surface and finally proceeds to produce acrylonitrile (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.

In addition, 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).

In recent years, a highly active multicomponent oxide catalyst having Mo-V-Te-Nb-O components has been developed and attracted much attention (Patent Document 1) And has a specific crystal structure of M1 and M2 directly associated with each other. 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 2). In addition, it is known that some of the reactions other than the ammoxidation reaction of propane are also highly active, and many studies have been conducted. However, since the catalyst is expensive and has low thermal stability, it has problems in commercialization (Non-Patent Document 5).

In order to solve the above problem, studies have been conducted to introduce a small amount of silica into a catalyst or introduce a diluent using silica sol (Patent Document 3). The diluent does not have a reactive activity per se, but has excellent thermal conductivity, which is used to prevent the formation of hot spots of the catalyst and to disperse the catalyst to improve its utilization. Catalysts using diluents are often used in bulk catalysts for economic reasons because they can exhibit the same performance activity with less catalyst amount. The Mo-V-Te-Nb-O catalyst used for the dehydrogenation of ethane is also known to exhibit more economical and high activity when alumina, titania, etc. are used as a diluent (Patent Document 4). Therefore, it is expected that the method using the diluent improves the thermal stability of the catalyst and improves the utilization thereof, thereby solving the above problems and reducing the production cost.

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. Also, the process using the currently developed propane is not 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 present invention also provides a reaction system that is more efficient than the conventional reaction system by selectively producing acrylonitrile through a propane ammoxidation reaction using the catalyst.

(Patent Document 1) United States Patent No. 6143690 (Patent Document 2) United States Patent No. 5422328 (Patent Document 3) US Patent No. 4624800 (Patent Document 4) United States Patent No. 8846996

(Non-Patent Document 1) J.-C. Volta, C. R. Acad. Sci., Ser. IIc: Chim., Vol. 3, pp. 717 (2000) (Non-Patent Document 2) D R.K. Grasselli, J. D. Burrington, D.J. Buttrey, P. DeSanto Jr., P. C. G., Lugmair, A.F. Volpe Jr., T. Weingand, Top. Catal. 23, 5 (2003) (Non-Patent Document 3) J. Belgacem, J. Kress, J.A. Osborn., J. Mol. Catal. A. 86, 267 (1994) (Non-Patent Document 4)] R.K. Grasselli, D.J. Buttrey, P. DeSanto Jr., J. D. Burrington, C.G. Lugmair, A.F. Volpe Jr., T. Weingand, Catal. Today 91, 251 (2004) (Non-Patent Document 5) R.K. Grasselli, J. D. Burrington, Handbook of heterogeneous catalysis, 2nd edn. VCH-Wiley, Weinheim, vol. 7, p. 3479 (2008)

Accordingly, it is an object of the present invention to provide a metal oxide catalyst for use in the ammoxidation reaction of propane.

It is also intended to synthesize acrylonitrile from propane having a low cost using the metal oxide catalyst.

According to an exemplary aspect of the present invention,

(a) preparing a precursor solution comprising a molybdenum precursor, a vanadium precursor, a tellurium precursor, and a niobium precursor;

(b) drying and calcining the precursor solution first; And

(c) injecting a diluent into the calcined sinter and secondly calcining the sintered calcined sinter, and a process for producing the metal oxide catalyst.

According to another exemplary aspect of the present invention, there is provided a method of manufacturing acrylonitrile using the metal oxide catalyst,

Wherein the metal oxide catalyst and propane are heat-treated under a nitrogen atmosphere to produce propylene by an ammoxidation reaction.

The metal oxide catalyst supported on the diluent according to the present invention has excellent thermal stability due to the introduction of a diluent, and has a high economic efficiency because it can achieve high performance even with a small amount of catalyst. In addition, active sites can be effectively distributed through diluents, greatly reducing side reactions and achieving higher catalyst productivity than when no diluent is used.

In addition, acrylonitrile can be easily prepared from propylene dianilpropane using the metal oxide catalyst, which can produce acrylonitrile directly from propane, thereby providing economical advantages and being able to actively cope with future market changes .

1 is a graph showing nitrogen adsorption / desorption isotherms of MVTN-X (X = Aerosil200, MCF, SBA15) catalysts prepared in Production Examples 1 to 3. FIG.
FIG. 2 is a graph showing X-ray diffraction analysis results of MVTN-X (X = Aerosil200, MCF, SBA15) catalysts prepared according to Production Examples 1 to 3.
3 is a graph showing the production results of acrylonitrile of Examples 1 to 3 produced using MVTN-X (X = Aerosil200, MCF, SBA15) catalysts prepared by Production Examples 1 to 3.
4 shows the results of acrylonitrile production in Examples 4 to 7 and Comparative Examples produced using MVTN-XMCF (X = 10, 15, 20, 40, 0 wt%) catalysts prepared in Production Examples 4 to 8 Fig.

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

The metal oxide catalyst to be provided in the present invention is for producing acrylonitrile using propane. The metal oxide catalyst can be used to provide acrylonitrile through ammoxidation reaction of propane.

According to an aspect of the present invention,

(a) preparing a precursor solution comprising a molybdenum precursor, a vanadium precursor, a tellurium precursor, and a niobium precursor;

(b) drying and calcining the precursor solution first; And

(c) adding a diluent to the calcined calcined material and calcining the calcined calcined material in a second step.

The step (a) is a step of preparing a precursor solution containing a molybdenum precursor, a vanadium precursor, a tellurium precursor and a niobium precursor, wherein the precursor solution is a mixture of a first precursor solution and a second precursor solution.

The step (a) comprises: (a-1) dissolving a molybdenum precursor, a vanadium precursor and a tellurium precursor in a first solvent to prepare a first metal precursor solution in which the molybdenum precursor, the vanadium precursor and the tellurium precursor are mixed (A-2) dissolving a niobium precursor and a reducing agent in a second solvent to prepare a second metal precursor solution, and (a-3) mixing the first metal precursor solution and the second metal precursor solution Followed by hydrothermal synthesis using an autoclave.

At this time, the precursor solution in step (a) is necessarily prepared by mixing the first precursor solution and the second precursor solution, and the reducing agent is added to the solvent together with the niobium precursor in the preparation of the second precursor solution, It is confirmed that this process does not deteriorate the activity of the catalyst even if the metal oxide catalyst finally produced is regenerated up to two times.

That is, when the molybdenum precursor, the vanadium precursor, the tellurium precursor and the niobium precursor are mixed together in the preparation of the precursor solution, the regenerating ability of the catalyst may be lowered. Therefore, The precursor solution is separately prepared and mixed, and the reducing agent must be separately dissolved in the solvent together with the niobium precursor.

Preferably, the molybdenum precursor, the vanadium precursor, and the tellurium precursor are mixed at an atomic ratio of 1: 0.05 to 5: 0.05 to 5, and in the step (a-1) A crystalline phase capable of inhibiting the activity of the compound can be formed. More preferably in an atomic ratio of 1: 0.4: 0.16.

The molybdenum precursor and the first solvent are preferably mixed in a weight ratio of 1: 1 to 30, more preferably 1: 6.

In the step (a-2), the niobium precursor and the reducing agent are preferably mixed in an atomic ratio of 1: 1 to 10, more preferably 1: 3.5.

The niobium precursor and the second solvent are preferably mixed in a weight ratio of 1: 1 to 30, more preferably 1: 12.

The reducing agent is preferably at least one selected from the group consisting of oxalic acid, tartaric acid, malonic acid succinic acid and phthalic acid.

In the step (a-3), the step of mixing the first precursor solution and the second precursor solution may be performed by heating the solution in the reactor as required.

In this case, the heating time may vary depending on the amount of the solution or slurry to be mixed, but is preferably 1 to 24 hours at a temperature of 50 to 100 ° C, more preferably at a temperature of 80 ° C for 3 hours Lt; / RTI >

After the heating and stirring, the solution or slurry may be lowered to room temperature, and then each solution or slurry may be mixed.

The hydrothermal synthesis may be carried out by stirring at a temperature of 50 to 200 ° C for 1 to 100 hours, preferably at a temperature of 120 to 200 ° C for 12 to 60 hours, more preferably at 175 ° C ≪ / RTI > for 48 hours. If the temperature of the hydrothermal synthesis is less than 50 캜 or more than 200 캜, different kinds of crystal phases may be formed, which is not preferable.

Examples of the molybdenum precursor include ammonium heptamolybdate, molybdenum oxide, molybdenum chloride, molybdenum oxychloride, molybdenum acetylacetonate, molybdenum oxytriethoxide, phosphomolybdic acid, And silicomolybdic acid are preferable.

The vanadium precursor is preferably at least one selected from ammonium metavanadate, vanadyl sulfate, vanadium oxide, vanadium chloride, vanadium oxychloride, vanadium oxytriethoxide, vanadium acetylacetonate and vanadyl acetylacetonate .

The tellurium precursor is preferably at least one selected from tellurium chloride, tellurium acetylacetonate, tellurium oxide, and tellurium acid.

In addition, the niobium precursor is preferably at least one selected from ammonium niobium oxalate, niobium oxide, niobium chloride, and niobium oxide.

In the step (b), the precursor solution prepared in the step (a) is first dried and then fired.

In order to dry the precursor solution, the precursor solution is first filtered using the first solvent, the second solvent or a mixture thereof used in the step (a) It is preferred to dry for a period of time. More preferably, the precursor solution is filtered using water and then dried in an oven at 120 DEG C for 12 hours.

The first firing may be performed at a temperature of 300 to 1200 ° C for 1 to 24 hours, preferably at a temperature of 500 to 800 ° C for 1 to 8 hours. The firing is performed at a temperature of less than 300 DEG C, or when the firing temperature exceeds 1200 DEG C A crystalline phase having no catalyst activity may be formed, which is not preferable.

In the step (c), the fired sintered material is dissolved in the third solvent, the diluent is added, dried, and then fired.

When the diluent is added and dried, it can be performed by heating the solution in the reactor. In this case, the heating time and temperature may vary depending on the amount of the mixed solution, but it is preferably 5 to 24 hours at a temperature of 30 to 150 ° C, more preferably 3 to 6 hours at a temperature of 85 ° C And that it is the most efficient.

The first, second and third solvents used in the steps (a) and (b) may be the same or different from each other and each independently selected from water, methanol, ethanol, 1- , 4-methyl-1-hexanol, 4-methyl-1-heptanol, benzyl alcohol, 1,2-ethanediol, glycerol, ditel glycols and trimethylene glycol.

The diluent is preferably at least one selected from the group consisting of silica, alumina, titania, zirconia and niobium oxide, more preferably silica.

The silica may be any material conventionally used, but preferably at least one selected from silica sol, Aerosil 200, MCF and SBA 15.

The blending ratio of the fired product and the diluent is preferably 1: 0.01 to 1, and if it is out of the above range, the selectivity may be lowered. More preferably, the fired product and the diluent are mixed at a weight ratio of 1: 0.15.

The secondary firing is preferably performed at a temperature of 500 to 800 DEG C for 1 to 8 hours.

More preferably, the first firing and the second firing may be performed in two stages. That is, the firing (primary and secondary) is first heat treated in an oxygen atmosphere at 200 to 350 ° C for 1 to 6 hours, then heated at a temperature of 500 to 700 ° C for 1 to 10 hours in a nitrogen atmosphere under an inert gas Heat treatment can be performed. If the calcination is carried out in two stages as described above, the impurities on the precursor can be removed through the first oxygen calcination and the crystallinity of the desired catalyst can be obtained through the second inert gas calcination. However, in some cases, it may be omitted in the case of primary oxygen firing.

Further, it is more preferable that the firing is performed in a tubular firing furnace (firing furnace), in order to maximize the firing efficiency by suppressing the loss of oxygen and nitrogen which are gases to be introduced. That is, when another kind of calcining furnace is used, loss of the gas is a concern, which is undesirable because the activity of the finally produced catalyst may be lowered.

According to another aspect of the present invention, there is provided a process for producing acrylonitrile using the metal oxide catalyst, wherein the metal oxide catalyst and propane are preferably prepared by an ammoxidation reaction of propane by heating under a nitrogen atmosphere .

The reaction temperature for promoting the ammoxidation reaction of the propane is preferably 300 to 800 ° C, and more preferably 300 to 500 ° C. If the reaction temperature is lower than 300 ° C, the propane is not sufficiently activated, and if it is higher than 500 ° C, it is not preferable due to decomposition reaction of propane.

The reaction product of the propane for ammonia oxidation reaction is a mixed gas containing propane, oxygen, ammonia and nitrogen, and has a volume ratio of propane: oxygen: ammonia: nitrogen of 1: 0.5-20: 0.1-10: 1: 50: 1, preferably 1: 1-5: 0.5-3: 5-20, more preferably 1: 3: 1.2: 15.

If the ratio of oxygen is out of the above range, the complete oxidation reaction occurs excessively or the activity of the catalyst becomes low. If the ratio of ammonia is out of the above range, the activity of the catalyst also decreases to decrease the selectivity of acrylonitrile, and it may cause problems in process stability, which is not preferable.

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) To 20,000 h < ^{-1 &} gt ;, and more preferably from 300 to 3,000 h < ^-1 >.

If the space velocity is less than 300 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 > is not preferable because the catalytic action can not sufficiently take place while the reactant passes through the catalyst layer.

Hereinafter, the present invention will be described in more detail with reference to Examples and the like, but the scope and content of the present invention can not be construed to be limited or limited by the following Examples. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the present invention as set forth in the following claims. It is natural that it belongs to the claims.

In addition, the experimental results presented below only show representative experimental results of the embodiments and the comparative examples, and the respective effects of various embodiments of the present invention which are not explicitly described below will be specifically described in the corresponding part.

(Preparation Examples 1 to 3: Preparation of Mo-V-Te-Nb metal oxide catalyst according to diluent characteristics)

A solution A was prepared by dissolving 20.97 g of ammonium heptamolybdate (AHM), 10.65 g of vanadyl sulfate hydrate and 4.55 g of telluric acid in 120 g of distilled water to prepare a solution A, Niobic acid (2.54 g) and oxalic acid dihydrate (6.32 g) were dissolved in 30 g of distilled water to prepare solution B. The two precursor solutions were stirred at a temperature of 85 캜 for 3 hours, cooled to room temperature, and mixed to prepare a precursor aqueous solution. The precursor aqueous solution was hydrothermally synthesized at a temperature of 175 ° C through an autoclave for 48 hours, filtered using distilled water, and dried in an oven at 120 ° C for 12 hours. Thereafter, the dried catalyst was subjected to a heat treatment for 2 hours while maintaining the temperature at 600 ° C. in a tubular fired apparatus of nitrogen atmosphere to obtain a solid material.

5 g of the solid material thus obtained and 1 g of the diluent were dissolved in 80 g of distilled water, stirred at 85 캜 for 5 hours, and sufficiently dried. Finally, Mo-V-Te-Nb (MVTN) metal oxide catalysts were prepared by heat treatment for 2 hours while maintaining the temperature at 600 ° C in a nitrogen-atmosphere fired furnace.

MVTN-Aerosil 200 (Production Example 1), MVTN-MCF (Production Example 2), MVTN-MCF (Production Example 2) and the like were prepared by using silica (SiO ₂ ) as a diluent, -SBA15 (Preparation Example 3).

division Characteristics of silica Size of pores Specific surface area Preparation Example 1 (Aerosil 200) - 200 m ² / g Preparation Example 2 (MCF) 10-35 nm 500-1000 m ² / g Production Example 3 (SBA15) 5-15 nm 500-800 m ² / g

( Manufacturing example  4 to 8: Depending on the diluent content Mo -V- Te - Nb  Preparation of Metal Oxide Catalyst)

V-Te-Nb (MVTN-XMCF) diluted in MCF was prepared in the same manner as in Preparation Example 1 except that the content of the diluent was adjusted to 10, 15, 20, 40 and 0 wt% , X = 10, 15, 20, 40, 0 wt%).

(Examples 1 to 7: Preparation of acrylonitrile using silica-supported MVTN catalyst)

The reaction for preparing acrylonitrile by the ammoxidation reaction of propane was carried out using the MVTN catalysts prepared in Production Examples 1 to 7.

In this embodiment, the ratio of the gas used was set to be 1: 3: 1.2: 15 for propane: oxygen: ammonia: nitrogen, and the amount of gas injected was set to a gas hourly space velocity (GHSV) Was 1,000 h < ^{-1 &} gt ;. Prior to the ammoxidation reaction of propane, the catalyst (0.2 g) was charged in a quartz reactor for activation of the catalyst, and the temperature was raised to a reaction temperature of 380 ° C at a rate of 5 ° C / min. Propane, oxygen, and ammonia were passed through the catalyst layer to conduct the propane ammoxidation reaction. In this 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) "

(Comparative Example: Preparation of acrylonitrile using MVTN catalyst)

Acrylonitrile was prepared in the same manner as in Example 1 except that the MVTN catalyst not supported on silica of Production Example 8 was used.

(Test Example 1: Characteristic Analysis of Metal Oxide Catalyst)

1 is a graph showing nitrogen adsorption / desorption isotherms of MVTN-X (X = Aerosil200, MCF, SBA15) catalysts prepared in Production Examples 1 to 3. FIG.

Referring to FIG. 1, all of the prepared catalysts showed pore characteristics of the silica used as a diluent, and the sintered solid powder was mixed with the diluent, so that the specific surface area was not high in all the catalysts. In addition, the diluents used were silica with significantly different pore and physical properties, and the effect of the pore and physical properties of the diluent on the reaction activity could be predicted.

Table 2 summarizes the results of nitrogen adsorption / desorption experiments of MVTN-X (X = Aerosil200, MCF, SBA15) catalysts prepared according to the above Production Examples 1 to 3, respectively. Referring to Table 2, the specific surface area of the prepared metal oxide catalyst was about 25-40 m ² g ^-1 , and the pore size of the pore size diluent remained unchanged.

division Specific surface area
(m ² / g) Pore volume
(cm < ³ > / g) Pore size
(nm) silica (Aerosil 200) 205 0.79 - silica (MCF) 806 1.11 16.1 silica (SBA15) 641 0.94 7.2 Production Example 1 27 0.3 - Production Example 2 34 0.15 16.1 Production Example 3 37 0.19 8.2

FIG. 2 is a graph showing X-ray diffraction analysis results of MVTN-X (X = Aerosil200, MCF, SBA15) catalysts prepared according to Production Examples 1 to 3.

Referring to FIG. 2, since the calcined solid powder was mixed with the diluent, the catalysts confirmed the peaks of the same M1 and M2 structures of the solid powder. No peaks or effects related to the silica used as a diluent were identified.

(Test Example 2: Production yield analysis of acrylonitrile using metal oxide catalyst)

3 is a graph showing the production results of acrylonitrile of Examples 1 to 3 produced using MVTN-X (X = Aerosil200, MCF, SBA15) catalysts prepared by Production Examples 1 to 3.

Referring to FIG. 3, higher propane conversion rates were observed than in the comparative example (MVTN bulk) where no reference diluent was used in all catalysts in the same active phase. This is believed to be due to the fact that the active phases, which have not been effectively dispersed in the MVTN bulk catalyst, can contact the reactants more. In the case of selectivity for acrylonitrile, different results were obtained depending on the diluent used. As a result of the experiment, it was found that the diluent having relatively small mesopore characteristics such as SBA15 had a negative effect on the selectivity, and Aerosil200 and MCF silica having no pore or relatively large size were considered to be suitable diluents. The results of the reaction of each catalyst are shown in Table 3 below.

Category (Unit,%) Propane conversion rate Aconitril selectivity Acrylonitrile water Example 1 89 51.8 46 Example 2 87 51 44.5 Example 3 87.6 42.9 37.6 Comparative Example 67.4 51.5 34.7

4 shows the results of acrylonitrile production in Examples 4 to 7 and Comparative Examples produced using MVTN-XMCF (X = 10, 15, 20, 40, 0 wt%) catalysts prepared in Production Examples 4 to 8 Fig.

Referring to FIG. 4, it can be seen that the selectivity of acrylonitrile is not significantly different as the amount of MCF increases, but is greatly lowered in Example 7 (MVTN-40MCF). It was considered that there was no significant change in the selectivity because the same active phase was used in the same amount. When excess MCF was used, the flow of the reactant was greatly disturbed and the selectivity to complete oxidation was greatly increased. The conversion of propane and the yield of acrylonitrile were increased and decreased. It is considered that the conversion rate is increased by the effectively distributed active phase as the MCF diluent is introduced, and when the excessive MCF is used, the conversion rate is slightly decreased as the reaction heat is easily exchanged through the diluent to decrease the temperature at which the active phase is sensed . The results of the reaction of each catalyst are shown in Table 4 below.

Category (Unit,%) Propane conversion rate Aconitril selectivity Acrylonitrile water Example 4 81.2 50.7 41.2 Example 5 94.5 53.2 50.3 Example 6 89.5 49.7 44.5 Example 7 86.5 28.8 24.9 Comparative Example 67.4 51.5 34.7

Therefore, the metal oxide catalyst supported on the silica according to the present invention promotes the ammoxidation reaction of propane, thereby remarkably improving the production yield of acrylonitrile.

Also, by using the metal oxide catalyst, acrylonitrile can be synthesized from propane, and a large amount of acrylonitrile can be provided at a low production cost.

Claims (15)

(a) preparing a precursor solution comprising a molybdenum precursor, a vanadium precursor, a tellurium precursor, and a niobium precursor;
(b) drying and calcining the precursor solution first; And
(c) injecting a diluent into the calcined fired powder and secondarily firing the fired calcined powder,
In the step (c), the weight ratio of the sintered material to the diluent is 1: 0.01 to 1,
The diluent is silica,
The precursor solution including the molybdenum precursor, the vanadium precursor, the tellurium precursor, and the niobium precursor is a mixture of the first metal precursor solution and the second metal precursor solution,
The first metal precursor solution is prepared by dissolving a molybdenum precursor, a vanadium precursor, and a tellurium precursor in a first solvent,
The second metal precursor solution is prepared by dissolving a niobium precursor and a reducing agent in a second solvent, the Mo-V-Te-Nb metal oxide catalyst prepared according to the process for producing a metal oxide catalyst; And
Propane is prepared by ammoxidation reaction of propane by heat treatment in a nitrogen atmosphere,
The ammoxidation reaction of propane is carried out at a temperature of 300 to 800 ° C under a condition that the total space velocity of propane, oxygen and ammonia is 100 to 20,000 h ^-1 ,
Wherein the volume ratio of propane, oxygen, ammonia, and nitrogen introduced into the propane is 1: 2-4: 0.5-2: 5-20.
delete delete delete delete The method according to claim 1,
Wherein the reducing agent is at least one selected from the group consisting of oxalic acid, tartaric acid, malonic acid, succinic acid, and phthalic acid.
The method according to claim 1,
The first solvent and the second solvent may be the same or different and each independently selected from the group consisting of water, methanol, ethanol, 1-propanol, 2-propanol, butanol, 1-heptanol, Is at least one selected from the group consisting of 1-heptanol, benzyl alcohol, 1,2-ethanediol, glycerol, deetelene glycol and trimethylene glycol.
The method according to claim 1,
The molybdenum precursor is 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 ≪ / RTI >
The method according to claim 1,
Wherein the vanadium precursor is at least one selected from ammonium metavanadate, vanadyl sulfate, vanadium oxide, vanadium chloride, vanadium oxychloride, vanadium oxytriethoxide, vanadium acetylacetonate and vanadyl acetylacetonate A process for the production of acrylonitrile.
The method according to claim 1,
Wherein the tellurium precursor is at least one selected from tellurium chloride, tellurium acetylacetonide, tellurium oxide, and tellurium oxide.
The method according to claim 1,
Wherein the niobium precursor is at least one selected from ammonium niobium oxalate, niobium oxide, niobium chloride, and niobium oxide.
The method according to claim 1,
Wherein the calcination in steps (b) and (c) is performed at a temperature of 300 to 1,200 ° C for 1 to 24 hours.
delete delete delete

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