KR101569233B1 - A method for increase-producing 1,3-butadiene from oxidative dehydrogenation reaction of n-butene and an apparatus thereof - Google Patents

Abstract

The present invention relates to a process for the production of butadiene through an oxidative dehydrogenation reaction of n-butene and an apparatus for use in the process, and more particularly to a process for producing a hydrocarbon-containing feedstock from a hydrocarbon-containing feed through an olefin plant, -butene rich stream is fed to an olefin conversion stage where n-butene is converted to propylene by reaction with ethylene, while C4-raffinate-3, which is the residual stream in the olefin conversion stage, Butadiene is converted into 1,3-butadiene in the butadiene step of the above-mentioned butadiene yielding a 1,3-butadiene mixture, and the obtained 1,3-butadiene mixture is purified, Butane and 1,3-butadiene, and the oxidation dehydrogenation reaction of n-butene circulated to the olefin plant It provides a method and apparatus through evaporation of the butadiene used therein.
According to the present invention, C4 Raffinate-3, which is incinerated for use as fuel after the olefin conversion step, is recycled through oxidative dehydrogenation of n-butene to produce normal and isotactic butane and 1 , 3-butadiene can be vaporized and can be immediately applied to a commercialization process.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for the production of butadiene by an oxidative dehydrogenation reaction of n-butene,

The present invention relates to a process for the production of butadiene through an oxidative dehydrogenation reaction of n-butene and an apparatus for use in the process, and more particularly to a process for producing a hydrocarbon-containing feedstock from a hydrocarbon-containing feed through an olefin plant, -butene rich stream is fed to an olefin conversion stage where n-butene is converted to propylene by reaction with ethylene, while C4-raffinate-3, which is the residual stream in the olefin conversion stage, Butadiene is converted into 1,3-butadiene in the butadiene step of the above-mentioned butadiene yielding a 1,3-butadiene mixture, and the obtained 1,3-butadiene mixture is purified, Butane and 1,3-butadiene, and the oxidation dehydrogenation reaction of n-butene circulated to the olefin plant It relates to a method of evaporating butadiene and apparatus used therein through.

In the olefin plant, naphtha is separated into ethylene, propylene, and crude C4 from an olefin plant, and the crude C4 is extracted and distilled to obtain C4-Raffinate-1 obtained after extraction of butadiene. (C4-Raffinate-3) after extraction of 1-butene from residual C4-Raffinate-2 after extraction of isotyping .

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At this time, C4-Raffinate-3 contains butene, but it is difficult to separate and it is generally burned for use as a fuel. However, when the amount of C4-raffinate-3 is large, the incineration cost is increased, and n-butene containing about 15% is also significant.

The present inventors have continued intensive research to solve the above-mentioned problems. As a result, they have found that, even if n-butene is converted into propylene by an olefin conversion apparatus without a complicated process, the residual C4- 3), a multi-component bismuth molybdate catalyst composed only of a metal component having high activity for the oxidative dehydrogenation reaction of n-butene was suitably applied to the step of purifying butadiene, .

Namely, since C4-Raffinate-3 used in the present invention contains normal type butane and at least 15 wt% of n-butene, the present inventors have succeeded in converting n-butene to butadiene Through the treatment of appropriately purifying, butadiene can be vaporized, the present invention has been accomplished.

It is therefore an object of the present invention to provide a process for the production of butadiene through the oxidative dehydrogenation reaction of butene which can be suitably purified by converting n-butene in the remainder C4-Raffinate-3 obtained from the olefin conversion step to butadiene, And a device used therefor.

In order to accomplish the above-mentioned object, a method for the production of butadiene through an oxidative dehydrogenation reaction of n-butene,
The n-butene rich stream in the hydrocarbon-containing fraction obtained from the hydrocarbon-containing feed through the olefin plant is fed to the olefin conversion stage and n-butene is reacted with ethylene in the olefin conversion stage to produce propylene However,

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The residual stream of the olefin conversion step, C4-raffinate-3, continues to the butadiene step, and in the butadiene step, n-butene is converted to 1,3-butadiene to give 1,3- The 1,3-butadiene dihydrate mixture obtained through the purification step is obtained as a mixture of normal type and isotactic butane and 1,3-butadiene, and is circulated to the olefin plant.

In order to accomplish the above object, an apparatus for vaporizing butadiene through an oxidative dehydrogenation reaction of n-butene,

A n-butene rich stream among the hydrocarbon-containing fractions obtained from the hydrocarbon-containing feed through the olefin plant is supplied to the olefin conversion unit through a pipeline, and in the olefin conversion unit, n- Reacted and converted to propylene,

The residue stream of C4- raffinate-3 of the olefin conversion device leads in order to increase production of butadiene unit and the purification unit for switching the n- butenes to 1,3-butadiene, wherein the purification unit CO, CO ₂ discharge line, An aldehyde / water discharge line, and a 1,3-butadiene mixture mixture discharge line, and the 1,3-butadiene vapor mixture is circulated to the olefin plant.

Hereinafter, the present invention will be described in detail.

The present invention relates to a process for the conversion of a n-butene rich stream in a hydrocarbon-containing fraction obtained from a hydrocarbon-containing feed through an olefin plant to an olefin conversion stage wherein n-butene is reacted with ethylene To propylene,
The residual stream of the olefin conversion step, C4-raffinate-3, continues to the butadiene step, and in the butadiene step, n-butene is converted to 1,3-butadiene to give 1,3- The 1,3-butadiene dihydrate mixture is purified through a purification step to obtain a mixture of normal and isotactic butane and 1,3-butadiene, and is circulated to the olefin plant.

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The step of vaporizing butadiene from such C4-raffinate-3 can be carried out by using a bismuth-molybdate-based catalyst to react the n-butene: oxygen: steam in the molar ratio of 1: 0.5 to 10: Lt; RTI ID = 0.0 > 380 C < / RTI > and a space velocity of 50 to 2000 h-1.

Specifically, the amount of air, which is another reactant, with the C4 mixture is precisely controlled using a mass flow controller. In order to inject steam, liquid water is supplied to each reactor by injecting water using a syringe pump. The temperature of the portion where the liquid water is injected is maintained at 150 to 300 ° C, preferably 180 to 250 ° C, and the water injected by the syringe pump is immediately vaporized to completely mix with other reactants (C4 mixture and air) To pass through the catalyst layer.

The bismuth-molybdate catalyst is a multicomponent bismuth molybdate catalyst, which is a catalyst having a molar composition ratio of Mo 1-15, Bi 1-10, Fe 1-10, Co 1-10, and Cs 0.01-1.5 And is preferably a catalyst having a molar composition ratio of Mo 1-15, Bi 1-10, Fe 1-10, Co 1-10, K 0.01-1.5, and Cs 0.01-1.5.

Specifically, the bismuth-molybdate-based catalyst is a multicomponent bismuth molybdate catalyst composed of five kinds of metal components, and includes a metal component having a divalent cation, a metal component having a trivalent cation, cesium, bismuth and molybdenum as a component , And it is possible to produce various multicomponent bismuth molybdate catalysts depending on the kinds of constituents and the ratio thereof. As the metal component having a divalent cation, cobalt and nickel are preferably used, and most preferably, cobalt is used. According to one embodiment of the present invention, a multicomponent bismuth molybdate consisting of cobalt, cesium, iron, bismuth and molybdenum The highest activity was observed in the oxidative dehydrogenation reaction using the libate catalyst. Potassium can be included here.

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The metal precursor for preparing these catalysts can be any metal conventionally used in the art. In the present invention, cesium nitrate is used as a precursor of cesium and cobalt nitrate (cobalt nitrate) is used as a precursor of cobalt. Iron nitrate is used as a precursor of iron, bismuth nitrate is used as a precursor of bismuth, and ammonium molybdate is used as a precursor of molybdenum. In order to maximize the yield of butadiene production to be achieved in the present invention, the molar ratio of cesium / cobalt / iron / bismuth / molybdenum precursor is preferably 0.01 to 1.5 / 1 to 10/1 to 5 / 2/5 to 20, preferably 1/9/3/1/12.

The cesium, cobalt, iron, and bismuth precursors are simultaneously dissolved in distilled water, and the molybdenum precursor is separately dissolved in distilled water and then mixed with each other. At this time, an acidic solution (for example, nitric acid) Can be added. When the precursors are completely dissolved, the precursor solution containing cesium, cobalt, iron, and bismuth is injected into the molybdenum-containing precursor solution to deposit the metal components. The coprecipitated solution is stirred for 0.5 to 24 hours, preferably 1 to 2 hours, so that sufficient coprecipitation is achieved.

Moisture and other liquid components are removed from the stirred solution to obtain a solid component sample. The obtained solid sample is dried at 20 to 300 ° C, preferably 150 to 200 ° C for 24 hours. The thus-produced solid catalyst was placed in an electric furnace and heat-treated at 300 to 800 ° C, preferably 400 to 600 ° C, and more preferably 450 to 500 ° C to prepare a bismuth-molybdate catalyst.

The catalysts of the present invention thus obtained were found to be highly active in n-butene, but inactive in n-butane, as described in the following examples.

According to the present invention, the oxidative dehydrogenation reaction of 1-butene and 2-butene is carried out by adsorbing n-butene, which is a reactant, in the catalyst, and then reacting with hydrogen in the butene in which oxygen is adsorbed in the catalyst lattice to form 1,3- And water, and the reaction proceeds with a pathway in which the molecular oxygen as a reactant fills the vacancy site of the catalyst lattice.

In addition, it is preferable that the above-mentioned butadiene-containing step is carried out using a shell-and-tube reactor having a multi-tube filled with the bismuth-molybdate-based catalyst and having a refrigerant circulation unit on the outside thereof, Do.

When the butadiene is subjected to the step of purifying it, the conversion of n-butene to 1,3-butadiene can be 95.4 to 95.9%, as is clear from the following examples.

The 1,3-butadiene vapor mixture obtained from the butadiene vaporization step advantageously comprises extractive distillation as a purification step. The extractive distillation is preferably configured so that the three product streams described above can be produced. Concretely, it is subjected to extractive distillation at room temperature and atmospheric pressure to remove liquid water and a by-product component of a solid phase, and CO and CO ₂ in a gaseous phase to obtain a reaction product containing normal and isotactic butane and 1,3-butadiene.

The obtained normal and isotactic butane and 1,3-butadiene-containing reactants may be further circulated to the olefin plant to separate the butane and 1,3-butadiene, or, if necessary, To the n-butene rich stream in the fraction, and circulating the n-butene rich stream.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is illustrated by comparing exemplary embodiments schematically shown in the drawings with the prior art.

An olefin plant (not shown) according to the prior art shown in Fig. 1 is operated using a naphtha supplied to the cracking furnace 1 through a line. It is also possible to provide the plant with a plurality of cracking furnaces, which convert the naphtha into cracking gases, which are supplied to a scrubber and fed to a fractionation step (not shown) by a compressor. In the fractionation step, olefin, pyrolysis gasoline, pyrolysis oil and light gas are removed through the ethylene line (3) and propylene line (4) and the like. At this time, the ethylene line 3 may be connected to the olefin conversion device 8 to be described later and converted to propylene.

Hydrocarbons having a crude carbon number of 4 obtained in the fractionation step are supplied to the first extraction distillation unit 6 through the line 5. In the primary extraction distillation unit 6, butadiene is extracted to convert to butadiene rubber, and C4-raffinate-1 is obtained as the remainder. The obtained C4-raffinate-1 is fed to a secondary extraction distillation unit 7, and isotyped butene is extracted and converted to MMA, and the remainder is C4-raffinate-2. The thus obtained C4-raffinate-2 is supplied to the olefin conversion device 8. [

For reference, the olefin conversion device 8 is not limited to this, but a commonly used catalyst bed phase reactor may be used.

Further, in the olefin conversion device 8, n-butene is extracted and converted to propylene to obtain C4-raffinate-3 (C4 Raffinate-3). The C4-raffinate-3 thus obtained has been incinerated for use as a fuel.

2, which is a process diagram according to an embodiment of the present invention, the C4-Raffinate-3 obtained in FIG. 1 is fed to a butadiene-distillation apparatus and 1,3-butadiene, A mixed mixture of aldehydes such as butane isobutane, CO, CO ₂ , acrolein and water is obtained.

The reactor for the butadiene vapor deposition apparatus used in the present invention is not limited thereto, but it is preferable to use a two-stage reactor connected in series through a pipeline to sequentially perform an oxidative dehydrogenation reaction in view of reaction efficiency.

At this time, it is particularly preferable that the reactor is filled with a bismuth molybdate-based catalyst as a catalyst-fixed phase.

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The mixture obtained from the butadiene distillation unit is fed to a refinery and is branched into a CO, CO ₂ outlet line, an aldehyde / water outlet line and a mixture outlet line of normal / isotactic butane and 1,3-butadiene. At this time, the purification apparatus may be an extractive distillation step.

This is because C4-raffinate-3 itself is difficult to separate due to its small difference in boiling point as shown in Table 1 below, but 1,3-butadiene can be separated from the C4 mixture by extractive distillation, and CO2, H2O, Aldehyde and the like are easily separated because of a large difference in boiling point with C4.

matter Boiling point (absolute temperature, K) matter Boiling point (absolute temperature, K) Isotyped butane 262.00 CO2 194 Isotyped butene 266.70 H2O 283 1-butene 266.80 Acrolein 330 1,3-butadiene 268.60 n-butane 273.00 trans-2-butene 274.20 Cis-2-butene 276.84

In the present invention, the mixture obtained in the mixture discharge line of normal / isotactic butane and 1,3-butadiene may be separated using an additional refining apparatus or the like, or may be connected to the remaining line of the olefin plant through a pipeline, It is also possible to do.

According to the present invention, the oxidative dehydrogenation of the residual n-butene of C4-Raffinate-3, which is incinerated for use as fuel after the olefin conversion step, is recycled to produce normal and isotactic butane And 1,3-butadiene, and has the advantage of being immediately applicable to commercialization processes.

The method and apparatus according to the present invention can produce high value-added C4 raffinate-3 at low cost by directly producing 1,3-butadiene with high utilization value from C4 raffinate- .

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic illustration of an apparatus for producing olefins from hydrocarbon mixtures according to prior art.
FIG. 2 is a schematic view of an apparatus for the production of 1,3-butadiene from C4-Raffinate-3 remaining after production of an olefin from a hydrocarbon mixture according to an embodiment of the present invention.

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

Preparation Example 1: Preparation of bismuth-molybdate-based catalyst [

Cobalt nitrate hexahydrate (Co (NO ₃ ) ₂ .6H ₂ O) was used as a precursor of cobalt and iron nitrate 9 hydrate (Fe ( NO _{3) 3} and 9H ₂ O), as the bismuth precursor is bismuth nitrate pentahydrate (Bi (NO _{3) 2} and 5H ₂ O), a molybdenum precursor is ammonium molybdate tetrahydrate ((NH ₄₎ 6Mo ₇ O ₂₄ .4H ₂ O) was used. Other metal precursors dissolve well in distilled water, but since bismuth nitrate pentahydrate is well soluble in strong acidic solutions, nitric acid solution is added to distilled water to dissolve bismuth nitrate pentahydrate separately.

The molar ratio of cesium: cobalt: iron: bismuth: molybdenum was fixed at 1: 9: 3: 1: 12 to prepare a catalyst.

(Fe (NO ₃ ) ₃ .9H ₂ O) of 3.94 g and cesium nitrate hexahydrate as a precursor of cesium, 7.94 g of cobalt nitrate hexahydrate (Co (NO ₃ ) ₂ .6H ₂ O) and 3.66 g of iron nitrate 9 hydrate Then, 1.47 g of bismuth nitrate pentahydrate (Bi (NO ₃ ) ₂ .5H ₂ O) was added to 15 mL of distilled water to which 3 mL of nitric acid had been added, and dissolved by stirring. After confirming that the bismuth was completely dissolved, the bismuth solution was added to the solution containing the precursor of cesium, cobalt and iron to prepare an acid solution in which the precursors of cesium, cobalt, iron and bismuth were dissolved.

Further, 6.36 g of ammonium molybdate tetrahydrate ((NH ₄ ) 6 Mo ₇ O ₂₄揃₄ H ₂ O) was dissolved in 100 ml of distilled water and stirred to prepare separately. An acidic solution in which the prepared nickel, iron, and bismuth precursors had been dissolved was dropped one by one into the molybdate solution.

The resulting mixed solution was stirred for 1 hour at room temperature using a magnetic stirrer, and then a solid sample was obtained from the precipitated solution using a vacuum or centrifugal concentrator. The obtained solid sample was dried at 175 DEG C for 24 hours. The resulting solid catalyst was placed in an electric furnace and heat treated at a temperature of 475 DEG C to prepare a bismuth-molybdate catalyst.

The prepared catalysts were confirmed successfully prepared by the X- ray diffraction and elemental composition analysis (ICP-AES), X- ray diffraction analysis, the catalyst is _{β-CoMoO 4, Fe 2 (} MoO 4) 3, α- Bi ₂ Mo ₃ O ₁₂ and γ-Bi ₂ MoO ₆ , and it was confirmed that the amount of metal precursors desired by us in the analytical error range was precisely determined through elemental component analysis (ICP-AES) .

The elemental composition ratio of the catalyst prepared according to Production Example 1 was 1: 9.0: 3.2: 1.0: 11.4 in terms of the relative ratio of Cs: Co: Fe: Bi: Mo to other metal components relative to Bi.

PREPARATION EXAMPLE 2 Preparation of Bismuth-Molybdate Catalyst-

Cobalt nitrate hexahydrate (Co (NO ₃ ) ₂ .6H ₂ O) was used as a precursor of cobalt and iron nitrate 9 hydrate (Fe ( NO _{3) 3} and 9H ₂ O), as the bismuth precursor is bismuth nitrate pentahydrate (Bi (NO _{3) 2} and 5H ₂ O), a molybdenum precursor is ammonium molybdate tetrahydrate ((NH ₄₎ 6Mo ₇ O ₂₄ .4H ₂ O) was used. Other metal precursors dissolve well in distilled water, but since bismuth nitrate pentahydrate is well soluble in strong acidic solutions, nitric acid solution is added to distilled water to dissolve bismuth nitrate pentahydrate separately.

The molar ratio of cesium: cobalt: iron: bismuth: molybdenum was fixed at 1.1: 9.1: 3.1: 1.1: 12.1 to prepare a catalyst.

(Fe (NO ₃ ) ₃ .9H ₂ O) of 3.94 g and cesium nitrate hexahydrate as a precursor of cesium, 7.94 g of cobalt nitrate hexahydrate (Co (NO ₃ ) ₂ .6H ₂ O) and 3.66 g of iron nitrate 9 hydrate Then, 1.47 g of bismuth nitrate pentahydrate (Bi (NO ₃ ) ₂ .5H ₂ O) was added to 15 mL of distilled water to which 3 mL of nitric acid had been added, and dissolved by stirring. After confirming that the bismuth was completely dissolved, the bismuth solution was added to the solution containing the precursor of cesium, cobalt and iron to prepare an acid solution in which the precursors of cesium, cobalt, iron and bismuth were dissolved.

Further, 6.36 g of ammonium molybdate tetrahydrate ((NH ₄ ) 6 Mo ₇ O ₂₄揃₄ H ₂ O) was dissolved in 100 ml of distilled water and stirred to prepare separately. An acidic solution in which the prepared nickel, iron, and bismuth precursors had been dissolved was dropped one by one into the molybdate solution.

The resulting mixed solution was stirred for 1 hour at room temperature using a magnetic stirrer, and then a solid sample was obtained from the precipitated solution using a vacuum or centrifugal concentrator. The obtained solid sample was dried at 175 DEG C for 24 hours. The resulting solid catalyst was placed in an electric furnace and heat treated at a temperature of 475 ° C to prepare a catalyst.

The prepared catalysts were confirmed successfully prepared by the X- ray diffraction and elemental composition analysis (ICP-AES), X- ray diffraction analysis, the catalyst is _{β-CoMoO 4, Fe 2 (} MoO 4) 3, α- Bi ₂ Mo ₃ O ₁₂ and γ-Bi ₂ MoO ₆ , and it was confirmed that the amount of metal precursors desired by us in the analytical error range was precisely determined through elemental component analysis (ICP-AES) .

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PREPARATION EXAMPLE 3 Preparation of Bismuth-Molybdate-based Catalyst-

Cobalt nitrate hexahydrate (Co (NO ₃ ) ₂ .6H ₂ O) was used as a precursor of cobalt and iron nitrate 9 hydrate (Fe ( NO _{3) 3} and 9H ₂ O), as the bismuth precursor is bismuth nitrate pentahydrate (Bi (NO _{3) 2} and 5H ₂ O), a molybdenum precursor is ammonium molybdate tetrahydrate ((NH ₄₎ 6Mo ₇ O ₂₄ .4H ₂ O) was used. Other metal precursors dissolve well in distilled water, but since bismuth nitrate pentahydrate is well soluble in strong acidic solutions, nitric acid solution is added to distilled water to dissolve bismuth nitrate pentahydrate separately.

The molar ratio of cesium: cobalt: iron: bismuth: molybdenum was fixed at 1.5: 9.5: 3.5: 1.5: 12.5 to prepare a catalyst.

(Fe (NO ₃ ) ₃ .9H ₂ O) of 3.94 g and cesium nitrate hexahydrate as a precursor of cesium, 7.94 g of cobalt nitrate hexahydrate (Co (NO ₃ ) ₂ .6H ₂ O) and 3.66 g of iron nitrate 9 hydrate Then, 1.47 g of bismuth nitrate pentahydrate (Bi (NO ₃ ) ₂ .5H ₂ O) was added to 15 mL of distilled water to which 3 mL of nitric acid had been added, and dissolved by stirring. After confirming that the bismuth was completely dissolved, the bismuth solution was added to the solution containing the precursor of cesium, cobalt and iron to prepare an acid solution in which the precursors of cesium, cobalt, iron and bismuth were dissolved.

Further, 6.36 g of ammonium molybdate tetrahydrate ((NH ₄ ) 6 Mo ₇ O ₂₄揃₄ H ₂ O) was dissolved in 100 ml of distilled water and stirred to prepare separately. An acidic solution in which the prepared nickel, iron, and bismuth precursors had been dissolved was dropped one by one into the molybdate solution.

The resulting mixed solution was stirred for 1 hour at room temperature using a magnetic stirrer, and then a solid sample was obtained from the precipitated solution using a vacuum or centrifugal concentrator. The obtained solid sample was dried at 175 DEG C for 24 hours. The resulting solid catalyst was placed in an electric furnace and heat treated at a temperature of 475 ° C to prepare a catalyst.

The prepared catalysts were confirmed successfully prepared by the X- ray diffraction and elemental composition analysis (ICP-AES), X- ray diffraction analysis, the catalyst is _{β-CoMoO 4, Fe 2 (} MoO 4) 3, α- Bi ₂ Mo ₃ O ₁₂ and γ-Bi ₂ MoO ₆ , and it was confirmed that the amount of metal precursors desired by us in the analytical error range was precisely determined through elemental component analysis (ICP-AES) .

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PREPARATION EXAMPLE 4 Preparation of Bismuth-Molybdate-based Catalyst-

Cobalt nitrate hexahydrate (Co (NO ₃ ) ₂ .6H ₂ O) was used as a precursor of cobalt and iron nitrate 9 hydrate (Fe ( NO _{3) 3} and 9H ₂ O), as the bismuth precursor is bismuth nitrate pentahydrate (Bi (NO _{3) 2} and 5H ₂ O), a molybdenum precursor is ammonium molybdate tetrahydrate ((NH ₄₎ 6Mo ₇ O ₂₄ .4H ₂ O) was used. Other metal precursors dissolve well in distilled water, but since bismuth nitrate pentahydrate is well soluble in strong acidic solutions, nitric acid solution is added to distilled water to dissolve bismuth nitrate pentahydrate separately.

The molar ratio of cesium: cobalt: iron: bismuth: molybdenum was fixed at 1.5: 9.9: 3.9: 1.9: 12.9 to prepare a catalyst.

(Fe (NO ₃ ) ₃ .9H ₂ O) of 3.94 g and cesium nitrate hexahydrate as a precursor of cesium, 7.94 g of cobalt nitrate hexahydrate (Co (NO ₃ ) ₂ .6H ₂ O) and 3.66 g of iron nitrate 9 hydrate Then, 1.47 g of bismuth nitrate pentahydrate (Bi (NO ₃ ) ₂ .5H ₂ O) was added to 15 mL of distilled water to which 3 mL of nitric acid had been added, and dissolved by stirring. After confirming that the bismuth was completely dissolved, the bismuth solution was added to the solution containing the precursor of cesium, cobalt and iron to prepare an acid solution in which the precursors of cesium, cobalt, iron and bismuth were dissolved.

Further, 6.36 g of ammonium molybdate tetrahydrate ((NH ₄ ) 6 Mo ₇ O ₂₄揃₄ H ₂ O) was dissolved in 100 ml of distilled water and stirred to prepare separately. An acidic solution in which the prepared nickel, iron, and bismuth precursors had been dissolved was dropped one by one into the molybdate solution.

The resulting mixed solution was stirred for 1 hour at room temperature using a magnetic stirrer, and then a solid sample was obtained from the precipitated solution using a vacuum or centrifugal concentrator. The obtained solid sample was dried at 175 DEG C for 24 hours. The resulting solid catalyst was placed in an electric furnace and heat treated at a temperature of 475 ° C to prepare a catalyst.

The prepared catalysts were confirmed successfully prepared by the X- ray diffraction and elemental composition analysis (ICP-AES), X- ray diffraction analysis, the catalyst is _{β-CoMoO 4, Fe 2 (} MoO 4) 3, α- Bi ₂ Mo ₃ O ₁₂ and γ-Bi ₂ MoO ₆ , and it was confirmed that the amount of metal precursors desired by us in the analytical error range was precisely determined through elemental component analysis (ICP-AES) .

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≪ Comparative Example 1 &

The results of analysis of C4-raffinate-3 obtained in the sequential process according to FIG. 1 are shown in Table 2 below.

division Raffinate-3 (wt%) C3 0.0 Isotyped butane 10.2 Normal type butane 64.0 Isotyped butene 5.4 1-butene 8.2 2-butene (trans) 5.7 2-butene (cis) 3.3 1,2-butadiene 0.0 1,3-butadiene 0.0

≪ Example 1 >

The C4-raffinate-3 obtained in Comparative Example 1 was fed into a shell-and-tube reactor packed with 200 ml of the catalyst prepared in Production Example 1 as a reactor for a butadiene distillation apparatus.

The ratio of oxygen / n-butene was 0.75, the ratio of steam / n-butene was 6, and the ratio of nitrogen / n-butene was 10. The temperature in the reactor was 340 ° C.

Thus, it was confirmed that the material discharged from the reactor for the butadiene distillation apparatus was composed of 1,3-butadiene, normal type and isotactic butane, CO, CO ₂ , acrolein, and water.

These materials were fed into a distillation column as a refining device, and the material fed through the butadiene / butane mixture discharge line could be separated into 1,3-butadiene, normal / isotyped butane and others via an additional purification device.

The reaction temperature, the conversion of normal type butane, the conversion of 1-butene, the selectivity of 1,3-butadiene, and the yield of 1,3-butadiene were respectively calculated for the reactor for the butadiene vaporizer.

≪ Example 2 >

The bismuth-molybdate-based catalyst obtained in Production Example 2 was charged in the former reactor, and the bismuth-molybdate catalyst obtained in Production Example 3 was charged in the subsequent reactor. The same procedure as in Example 1 was repeated, The same process as in Example 1 was repeated except that the molybdate-based catalyst was charged and the butadiene reaction was repeated twice.

≪ Example 3 >

The same procedure as in Example 2 was repeated except that a two-stage reactor connected in parallel with the distillation column and connected in parallel via a pipeline was used. The distillation column was composed of a C4 mixture containing normal butene and a 1-butene- Steam is supplied to the upper reactor among the two-stage reactors, the upper reactor is filled with the bismuth molybdate-based catalyst prepared in Production Example 2 as a catalyst-fixed phase, and the lower reactor of the two- Containing high boiling fraction and air and steam were fed as the remainder separated from the distillation column and the bismuth molybdate-based catalyst prepared in Production Example 4 was charged in the lower stage reactor on the catalyst-fixed phase. Was repeated.

<Example 4>

The same process as in Example 1 was repeated except that the temperature was changed to 380 캜, and the same process as in Example 1 was repeated.

&Lt; Comparative Example 2 &

The same procedure as in Example 1 was repeated except that the temperature condition was changed to 420 캜 in Example 1.

Each conversion rate was calculated according to the following equation.

[Equation 1]

n-butene conversion ratio = (n-butene reacted / n-butene supplied) X 100

&Quot; (2) &quot;
Butadiene selectivity = (moles of produced 1,3-butadiene / moles of n-butene reacted) x 100

In comparison with Comparative Example 2 containing other metals, the improved results were confirmed in Examples 1-4 of the present invention. Among the Comparative Examples 2 and 3, in which the C4 mixture was treated with a catalyst alone in a single reactor, Of Example 2-3 of the present invention in which the catalyst was separately applied to a continuous reactor or a parallel reactor.

Further, improved results can be confirmed in Examples 1 and 4 of the present invention as compared to Comparative Example 3 in which the temperature condition is out of range as a specific condition.

It was confirmed that the effect of 1,3-butadiene on the production of C4-raffinate-3 was comparable to that of Comparative Example 1, and that it was immediately applicable to the commercialization process.

1: cracking furnace (NCC)
2, 3, 4,
6, 7: Extraction distillation unit
8: Olefin conversion device
9: Butadiene vaporizer
10, 14: Purification device
11: CO, CO ₂ emission line
12: Aldehyde / water discharge line
13: 1,3-Butadiene and isotactic butane-containing mixture discharge line

Claims (17)

The n-butene rich stream in the hydrocarbon-containing fraction obtained from the hydrocarbon-containing feed through the olefin plant is fed to the olefin conversion stage and n-butene is reacted with ethylene in the olefin conversion stage to produce propylene However,
The residual stream of the olefin conversion step, C4-raffinate-3, continues to the butadiene step, and in the butadiene step, n-butene is converted to 1,3-butadiene to give 1,3- Butadiene is fed to the olefin plant through a purification step to obtain a mixture of normal and isotactic butane and 1,3-butadiene, and the molar ratio of molybdenum (Mo), isobutene A bismuth-molybdate catalyst including bismuth (Bi), iron (Fe), cobalt (Co) and cesium (Cs)
The bismuth-molybdate catalyst is a catalyst having a molar composition ratio of Mo 1-15, Bi 1-10, Fe 1-10, Co 1-10, K 0.01-1.5, and Cs 0.01-1.5, or Mo 1- 15, Bi 1-10, Fe 1-10, Co 1-10, and Cs 0.01-1.5.
A process for the production of butadiene by oxidative dehydrogenation of n - butene. delete delete delete The method according to claim 1,
The butadiene step is carried out at a reaction temperature of 320 to 380 占 폚 and a reaction temperature of 50 to 2000 占 폚, using a bismuth-molybdate-based catalyst in a reactant containing n-butene: oxygen: steam in a molar ratio of 1: 0.5 to 10: RTI ID = 0.0 &gt; h-1 &lt; / RTI &gt;
A process for the production of butadiene by oxidative dehydrogenation of n - butene. delete delete The method according to claim 1,
Wherein the butadiene-vaporizing step is carried out using a shell-and-tube reactor having a multi-tube filled with the bismuth-molybdate-based catalyst and fixed thereon, and having a refrigerant circulating unit at the outside thereof
A process for the production of butadiene by oxidative dehydrogenation of n - butene. 6. The method of claim 5,
The conversion of n-butene to 1,3-butadiene in the butadiene-yielding step is 95.4 to 95.9%.
A process for the production of butadiene by oxidative dehydrogenation of n - butene. The method according to claim 1,
Wherein the purification step comprises distilling the mixture at room temperature and atmospheric pressure to remove liquid water, by-product components in the solid phase, and gaseous CO and CO ₂ from the 1,3-butadiene-
A process for the production of butadiene by oxidative dehydrogenation of n - butene. The method according to claim 1,
The isotactic butane and 1,3-butadiene-containing reactants which have undergone the purification steps are then circulated to the olefin plant to separate each butane and 1,3-butadiene; &Lt; RTI ID = 0.0 &gt;
A process for the production of butadiene by oxidative dehydrogenation of n - butene. delete delete delete delete delete delete

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