KR20180077768A - Method for producing conjugated diene - Google Patents

Abstract

The present invention relates to a method and an apparatus for producing butadiene. According to the present invention, when butadiene is produced through oxidative dehydrogenation of butene, butane is used instead of nitrogen as a diluent gas. Instead of a conventional absorption method used when butadiene is separated from a reaction product when using a nitrogen, provided is a condensation method for liquefying and separating butadiene by using a low-temperature refrigerant or cooling water. A high boiling point material in condensed crude hydrocarbon is pre-removed prior to a purification step, and thus a process load of a purification part is reduced. Also, high purity butadiene can be obtained.

Description

[0001] METHOD FOR PRODUCING CONJUGATED DIENE [0002]

The present invention relates to a process for producing butadiene, and more particularly, to a process for producing butadiene, which is capable of securing high purity butadiene, such as reduction of energy and raw material costs, improvement of productivity, and the like.

Butadiene is used as an intermediary for many petrochemical products in the petrochemical market. It is one of the most important basic oil in the petrochemical market and its demand and value are gradually increasing.

Butadiene can be produced by extraction from C4 oil by naphtha cracking, direct dehydrogenation of butene, and oxidative dehydrogenation of butene.

The method of preparing butadiene through the oxidative dehydrogenation reaction of butenes uses the reaction of removing two hydrogen from butene by using oxygen as a reactant to produce butadiene. Since the product is stable water, it is thermodynamically And it is an exothermic reaction unlike the direct dehydrogenation reaction, so that a higher yield of butadiene can be obtained even at a lower reaction temperature than the direct dehydrogenation reaction. Thus, the preparation of butadiene by the oxidative dehydrogenation of butene can be an effective way to meet the increasing demand for butadiene.

Meanwhile, in the oxidative dehydrogenation process of butene, nitrogen, steam or the like is used as a diluting gas in addition to raw materials for the purpose of reducing the risk of explosion due to oxygen and eliminating reaction heat, A method of absorbing hydrocarbons in a reaction product by using a solvent to separate hydrocarbons from a reaction product containing a slight gas phase (COx, O _2, etc.), hydrocarbons, etc., and a method of liquefying hydrocarbons by cooling the reaction product The absorption method is mainly used in the method. This is because the method of liquefying and separating the reaction product requires a cryogenic refrigerant when liquefied due to a dilution gas present in the reaction product and a light gas stream or the like, which makes it difficult to secure the economical efficiency of the process due to an increase in equipment cost and operating cost .

In this regard, FIG. 1 is a view for explaining a conventional butadiene producing apparatus and method.

1, an oxidative dehydrogenation reaction unit 110 for producing an oxidative dehydrogenation reaction product comprising butadiene, oxygen (O ₂ ), steam, and butadiene from a reaction raw material containing nitrogen as a diluent gas; A cooling separation section 120 for separating water from the oxidative dehydrogenation reaction product obtained from the oxidative dehydrogenation reaction; An absorption separator 130 separating the C4 mixture and the hydrocarbons including butadiene or butadiene from the oxidation dehydrogenation reaction product in which the water is separated; And a purifier 140 separating butadiene from a stream containing butadiene separated from the absorption separator 130.

The oxidative dehydrogenation reaction unit 110 may be formed by reacting a reaction raw material containing butene, oxygen (O ₂ ), steam, diluent gas (N ₂ ), and unreacted butenes recovered in the purification unit, And may be driven under isothermal or adiabatic conditions using a bismuth molybdate-based catalyst.

The cooling separator 120 may be driven by a quencher or an indirect cooling system.

FIG. 1 illustrates an example of selectively separating butadiene only from the absorption separator 130. However, the absorption separator 130 selectively absorbs butadiene only from the reaction product from which water is removed, or the entire hydrocarbons including a C4 mixture A solvent capable of absorbing water can be used. For example, ACN (Acetonitrile), NMP (N-methylpyrrolidone), or DMF (dimethyl formamide) may be used as the selective absorption solvent. Toluene and xylene may be used as the total absorption solvent. COx and O ₂ separated from the absorption separator 130 and N ₂ used as a diluting gas are all incinerated or partially recovered to be reused and partially incinerated.

The purification unit 140 may be an ACN (acetonitrile) process, a NMP (N-methylpyrrolidone) process, or a DMF (dimethyl formamide) process as a conventional butadiene refining apparatus. So that the butadiene can be purified.

In general, however, a large amount of energy is used in the process of recovering most of the solvent and the recovery and purification of butadiene in the purification unit 140. Also, even if the absorption separation process is replaced with a condensation separation process, it is necessary to develop a manufacturing method and a manufacturing apparatus capable of improving the economical efficiency of the process such as energy, raw material cost and production cost because a cryogenic refrigerant is required.

Korea Patent Publication No. 2012-0103759

In order to solve the problems of the prior art as described above, the present invention relates to an absorption method used for separating butadiene from reaction products during the use of conventional nitrogen using butane instead of nitrogen as a diluent gas in the production of butadiene through oxidative dehydrogenation of butene The present invention provides a method for producing butadiene by which a high-purity butadiene can be obtained by removing a high boiling point substance from hydrocarbons obtained through condensation separation by employing a condensation separation method in which butadiene is liquefied and separated by using a low temperature refrigerant or cooling water .

These and other objects of the present invention can be achieved by the present invention described below.

In order to achieve the above object,

A process for producing an oxidative dehydrogenation reaction product comprising butadiene, oxygen (O ₂ ), steam, and diluent gas by passing the reaction raw material through an oxidative dehydrogenation reaction unit,

Separating the water while passing the oxidative dehydrogenation reaction product containing the butadiene through the cooling separator,

Passing the oxidized dehydrogenation reaction product separated from the water to the condensation separation unit, condensing the hydrocarbons and separating COx and O ₂ ,

Further separating COx and O ₂ while passing condensed n-butane, butene and butadiene-containing hydrocarbons through the deaeration section in the condensation separation section,

Separating the high boiling point material while passing through the high boiling point remover, the crude hydrocarbons including n-butane, butene and butadiene, from which COx and O ₂ are further separated and condensed;

Separating the butadiene while passing the crude hydrocarbon from which the high boiling point material has been removed to the refining unit,

Wherein the n-butane-butene-containing gas except for the butadiene separated from the purification unit is re-introduced into the oxidative dehydrogenation reaction unit, and the diluent gas is butane.

The present invention also provides an oxidative dehydrogenation reaction unit for obtaining an oxidative dehydrogenation reaction product comprising butadiene by oxidative dehydrogenation reaction of a reaction raw material containing butene, oxygen (O ₂ ), steam, and diluent gas;

A cooling separator for separating water from the oxidative dehydrogenation reaction product comprising the butadiene;

A condensation separator for condensing the hydrocarbons in the oxidative dehydrogenation reaction product containing the butadiene from which the water is separated, and separating COx and O ₂ ;

A deaerator for further separating CO x and O ₂ from hydrocarbons containing n-butane, butene and butadiene condensed in the condensation separator;

Rejection of high boiling point by the COx and O ₂ separated by the additional and separate the high boiling point material in the crude hydrocarbon containing condensed n- butane and butadiene claim; And

And a purifier for separating butadiene from the crude hydrocarbon from which the high boiling point material has been removed,

Wherein the n-butane and butene-containing gas excluding the butadiene separated from the purification unit is re-introduced into the oxidative dehydrogenation reaction unit, and the diluent gas is butane.

According to the present invention, instead of nitrogen as a diluent gas, butane is used to separate a C4 mixture and a gaseous product except for butadiene through a condensation separation method using a low-temperature refrigerant instead of the cryogenic refrigerant required in the conventional separation process The high boiling point material can be removed before the purification of the hydrocarbons obtained through condensation to obtain the high-purity butadiene while reducing the process load of the purification part. Thus, the economical efficiency of the process such as reduction of energy and raw material cost, And to provide a method for producing butadiene which can be obtained and an apparatus for producing the same.

1 is a view for explaining a conventional butadiene production apparatus and a production method thereof.
FIGS. 2 and 3 are diagrams for explaining a butadiene production apparatus and a production method according to the present invention.

Hereinafter, the butadiene production method and the production apparatus of the present invention will be described in detail.

The butadiene production method and apparatus of the present invention introduces a condensation separation process in which butane is used as a diluting gas, introduces a high boiling point removal unit for removing high boiling point substances from hydrocarbons obtained through a condensation separation process, And a gas containing n-butane and butene except for the butadiene is fed into the oxidation dehydrogenation reaction section. When the condensation separation process is introduced, even if the absorption and separation process performed using the cryogenic refrigerant in the existing absorption separation process is excluded, the oxidation dehydrogenation reaction products including hydrocarbons can be easily separated to reduce the process load and energy consumption By introducing a high boiling point material removal process after the condensation separation process, the process load of the purification section can be reduced and high purity butadiene can be obtained. Also, the application of the recycle stream can significantly reduce the amount of untreated gas that is released into the atmosphere.

Hereinafter, the method and apparatus for producing butadiene of the present invention will be described in detail with reference to the drawings. 2 and 3 are diagrams for explaining the apparatus and method for producing butadiene according to the present invention.

2, first, a reaction raw material containing butene, oxygen (O ₂ ), steam, and diluent gas (butane) is passed through an oxidative dehydrogenation reaction unit 310 to produce an oxidative dehydrogenation reaction including butadiene And the flow B1 discharged in the oxidative dehydrogenation process flows into the cooling separator 320 to separate the water. At this time, the reaction raw material joins with the discharge flow B7 generated after the purification treatment in the purification process and another discharge flow B8, and flows into the oxidation dehydrogenation reaction unit 310. Butane, O ₂ , CO x, H ₂ O and the like may be included in the discharged stream B 2 in the oxidative dehydrogenation reaction step. The discharged stream B ₂ generated after the cooling and separation may contain butadiene, n Butane, butene, O ₂ , COx, and the like.

The exhaust stream B2 generated after the cooling and separating condenses the hydrocarbons while passing through the condensation separator 330 and the exhaust stream B4 'generated after the condensation separation is introduced into the deaerator 350, The discharge stream B4 'may include n-butane condensed in the condensation separator 330, hydrocarbons including butene and butadiene. In the condensate separation process, condensed hydrocarbons, COx, and O ₂ may be condensed through the compression / cooling of the hydrocarbons by using cooling water or the like.

A discharge flow (B4 ') occurs after said separating condensate are the flows into the degassing unit 350, separated by additional COx, O ₂ is separated further includes a discharge flow (B4 ") occurs after the degassing COx and O Butane, butane and butadiene except for ₂ , and the effluent stream B4 " may flow into the high boiling point refiner 360 and the high boiling point material may be removed. The degassing may contain a further draw stream (B5) is separated COx and O ₂ occurs later, since it can be incinerated.

The discharged stream B4 '' generated after the removal of the high boiling point may contain crude hydrocarbon from which a high boiling point material has been removed and may be introduced into the purification unit 340 to purify the butadiene more effectively.

The exhaust stream (B7) generated after the purification may contain abundant n-butane residue to form a recirculation flow into the oxidation dehydrogenation reaction unit (310), and another exhaust stream (B8) may contain residual butenes and mix with fresh butenes to form a recycle stream to be fed into the oxidative dehydrogenation reactor (310).

The heat generated by incineration of COx and O ₂ separated from the condensation separation unit or the heat generated by incineration of COx and O ₂ separated from the deaeration unit may be heated up or recycled in the purification unit A heat exchange unit may be provided between the condensation separation unit and the oxidative dehydrogenation reaction unit or between the condensation separation unit and the deaeration unit or between the condensation separation unit and the oxidation dehydrogenation reaction unit and the deaeration unit.

The term " curd hydrocarbon " refers to crude hydrocarbons commonly used in this technical field. Unless otherwise specified, hydrocarbons including butadiene and the like obtained from the oxidative dehydrogenation reaction product, Refers to raw materials.

The term " COx " refers to CO, CO ₂ unless otherwise determined.

The butene may be 1-butene, 2-butene or a mixture thereof. The raw material gas containing butene is not particularly limited in the case of raw material gas containing butene which can be generally used for the production of butadiene.

For example, the butene can be obtained from a hydrocarbon mixture containing butenes, such as butene gas of high purity, raffinate-2, raffinate-3, and the like among the C4 oils produced by naphtha cracking.

The steam is a gas which is injected for the purpose of preventing the coking of the catalyst and eliminating the reaction heat while reducing the risk of explosion of the reactant in the oxidative dehydrogenation reaction.

On the other hand, the oxygen (O ₂ ) reacts with butene as an oxidizing agent to cause a dehydrogenation reaction.

The catalyst packed in the reactor is not particularly limited as long as it can produce butadiene by oxidative dehydrogenation reaction of butene, and may be, for example, a ferrite catalyst or a bismuth molybdate catalyst.

In one embodiment of the present invention, the catalyst may be a ferrite-based catalyst. Among them, use of zinc ferrite, magnesium ferrite, and manganese ferrite may enhance the selectivity of butadiene. The type and amount of the reaction catalyst may vary depending on the specific conditions of the reaction.

The diluent gas may be butane.

The oxidative dehydrogenation reaction unit 310 may include butene, oxygen (O ₂ ), steam and residues from which the butadiene is separated from the purifier 340. The oxidation dehydrogenation reaction unit 310 may include n -Butane and butene as a reaction raw material and is driven under isothermal or adiabatic conditions using a ferritic catalyst.

For example, the oxygen (O ₂ ) contained in the reaction raw material may be introduced in a gaseous form having a purity of 90% or more, 95% or more, and preferably 98% or more.

The gas form having a purity of 90% or more may mean that oxygen (O ₂ ) is not introduced from the air but is introduced in the form of pure oxygen gas. Thus, the amount of the active ingredient, So that the amount of the components contained in the reaction raw material fed into the reactor can be individually controlled.

For example, the reaction conditions in the oxidative dehydrogenation reaction unit 210 may be a molar ratio of butene: oxygen: water vapor: diluent gas (n-butane) = 1: 0.5-3: 0.1-20: 0.1-20, It is possible to achieve economical efficiency of processes such as reduction of energy and raw material costs and improvement of productivity.

As a specific example, the oxidative dehydrogenation reaction unit 310 may be configured such that the mole ratio of oxygen to butene is 0.5 to 3: 1, the mole ratio of steam to butene is 0.1 to 20: 1, the mole ratio of n-butane- 1, the reaction pressure is atmospheric pressure ~ 10 atm, and the reaction temperature is 150 ~ 650 ° C. Within this range, it is possible to achieve economical efficiency of the process such as reduction of energy and raw material costs and improvement of productivity.

The cooling separator 320 may be driven by a quencher or an indirect cooling method, for example, the quenching temperature may be 0 to 100 ° C.

For example, the condensation separator 330 may have a single-stage single compression structure, a multi-stage compression structure of two to ten stages, or a multi-stage compression structure of one or two stages. The reason for performing the above-described multi-step compression is that, when compressed from the initial pressure to the target pressure at one time, not only a lot of power is required but also heat due to gas compression is generated and the gas expands and the compression efficiency is lowered. So that the heat generated in the compression process can be cooled using a cooler.

The condensation condition in the condensation separator 330 may be determined so as to have a range in which the flow exceeds the explosion range (above the explosion upper limit or below the critical oxygen concentration) in consideration of unreacted oxygen.

In an embodiment of the present invention, the refrigerant used in the condensing and separating unit 330 may be any one selected from the group consisting of cooling water, ethylene glycol, an ethylene glycol aqueous solution having a concentration of 20 to 100% by weight, propylene glycol, a propylene glycol aqueous solution having a concentration of 30 to 100% Propylene-based solvents, and propylene-based solvents.

 The propylene-based solvent is, for example, a compound containing propylene or propylene, and may be a substance having a boiling point of -10 ° C or less or -10 to -50 ° C.

Conventionally, when nitrogen is used as a diluent gas and a gas product is separated by a general distillation method, it is required to use a refrigerant at a very low temperature. In the present invention, a lower grade refrigerant can be used by introducing butane into a diluent gas.

As a specific example, the refrigerant may be cooling water, cooling water at 0 to 40 ° C, or cooling water at 5 to 30 ° C. In this case, the extrusion discharge temperature may be 250 ° C or less, or 50 to 250 ° C, May be 120 占 폚 or lower, or 20 to 80 占 폚.

When COx and O ₂ separated from the condensation separator 330 are incinerated, heat generated by incineration can be recycled in the oxidation dehydrogenation reactor 310.

The deaerator 350 may be driven by stripping or degassing using a conventional column, for example.

The COx and O _{2 that} are further separated from the deaerator 350 may be recycled in the oxidizing dehydrogenation reactor 310 when incinerated.

The high boiling point remover 360 may be driven by a distillation method, for example.

By first removed prior to the COx and O ₂ is the purified high-boiling substances in the added hydrocarbons include n- butane and the condensed butadiene separated as it is possible to obtain a highly pure butadiene.

The high-boiling substance may be, for example, aromatic hydrocarbons such as benzene, styrene and phenol, butadiene dimer, acetopyrone, benzophenone or anthrequinone.

The purification unit 340 may be a conventional apparatus for purifying butadiene. If necessary, it may be a process capable of applying separated butadiene, for example, an ACN (Acetonitrile) process, an NMP (N-methylpyrrolidone) process, DMF (dimethyl formamide) process.

In the purifier 340, the butadiene can be recovered as highly pure butadiene by removing the solvent and low boiling point components.

In one embodiment of the present invention, the purity of finally obtained butadiene through the series of steps may be 95.0 to 99.9%.

FIG. 3 is a view in which CO ₂ and O ₂ separated from the degassing unit 450 are introduced into a condensing system (not shown) by replacing the discharge flow B 5 generated after degassing with the discharge flow B 6 introduced into the condensing system And the gas separation efficiency can be improved by circulating the gas to the condensation separator 430.

Unless otherwise specified, the condensing system refers to a system including a compressor 431, a heat exchanger 432, and a condensation separator 430.

3, first, a reaction raw material containing butene, oxygen (O ₂ ), steam, and a diluent gas (butane) is passed through an oxidative dehydrogenation reaction unit 410 to produce an oxidative deoxidation reaction including butadiene And the product flows into the cooling separator 420 along the flow B1 discharged in the oxidative dehydrogenation process, and the water is separated. At this time, the reaction raw material joins with the discharge flow B7 generated after the purification treatment in the purification process and another discharge flow B8, and flows into the oxidation dehydrogenation reaction unit 410. The discharge flow B1 discharged from the oxidative dehydrogenation process may include butadiene, n-butane, butene, O ₂ , COx, H ₂ O and the like. n-butane, butene, O ₂ , COx, and the like.

The exhaust stream B4 'generated after the condensation and separation is introduced into the deaeration unit 450 and the exhaust stream B4' is condensed by the condensate separation unit 430, ) May include n-butane condensed in the condensation separator 430, and hydrocarbons including butene and butadiene. In the condensate separation process, condensed hydrocarbons, COx, and O ₂ may be condensed through the compression / cooling of the hydrocarbons by using cooling water or the like.

The post-condensation separate discharge flow occurs (B4 ') is added COx, O ₂ is separated flows into the degassing unit 450, and separated further has a discharge flow (B4 ") occurs after the degassing COx and O may include a hydrocarbon containing the crude condensed n- butane, butene and butadiene, except _2, and the discharge flow (B4 ") it may be introduced into the high boiling point remover 460, a high-boiling material removal. May contain another draw stream (B6) is added and the separated COx O ₂ occurs after the deaeration and was circulated to the condenser is added to the condensation separation system 430 can improve the gas separation efficiency.

The discharge stream B4 '' 'generated after removing the high boiling point may contain crude hydrocarbon from which a high boiling point material is removed, and the discharge stream B4' '' may be introduced into the refining unit 440 to remove butadiene It can be refined more effectively.

The effluent stream B7 generated after the purification may contain abundant n-butane residue and form a recirculation flow to be fed into the oxidative dehydrogenation reaction unit 410, and another effluent stream generated after the purification B8 may contain residual butenes and mix with fresh butene to form a recycle stream to be fed into the oxidative dehydrogenation reaction unit 410. [

Referring to FIG. 2, an example of a production apparatus used in the above production method is an apparatus for oxidative dehydrogenation of a reaction raw material containing butene, oxygen (O ₂ ), steam and diluent gas (butane) An oxidation dehydrogenation reaction unit 310 for obtaining an oxidation dehydrogenation reaction product; A cooling separation part (320) for separating water from the oxidative dehydrogenation reaction product comprising butadiene; A condensation separator 330 for condensing hydrocarbons in the oxidative dehydrogenation reaction product containing the butadiene from which the water is separated and separating COx and O ₂ ; A deaerator 350 for further separating COx and O ₂ from a discharge flow B4 'containing hydrocarbons containing n-butane, butene and butadiene condensed in the condensing separator 330; The degassing unit 350 add a high boiling point remover for removing high boiling substances from the exhaust stream (B4 "), including the condensed hydrocarbons, except for COx and O ₂ separated in (360); (B4 ''') containing crude hydrocarbons from which the high boiling point material has been removed is introduced into the purifier 340.

The n-butane-containing gas other than the butadiene separated from the purifier 340 is discharged to the oxidative dehydrogenation reactor 310 and the exhaust stream B7 is discharged from the purifier 340, A butane-containing gas except for butadiene joins the fresh butene and has a discharge flow B8 which is reintroduced into the oxidative dehydrogenation reaction unit 310. [

Another discharge stream B3 of the condenser / separator 330, or another discharge stream B5 of the deaerator may be incinerated.

In reference to FIG. 3 as an example of another manufacturing apparatus, butene, oxygen (O _2), water vapor (steam) and a dilution gas (butane) oxidative dehydrogenation, which was a reaction raw material digestion reaction dehydroxylation containing butadiene the An oxidative dehydrogenation reaction unit 310 for obtaining a reaction product; A cooling separation section (420) for separating water from the oxidative dehydrogenation reaction product comprising the butadiene; A condensation separator 430 in which hydrocarbons are condensed and COx and O ₂ are separated from the oxidative dehydrogenation reaction product comprising the butadiene in which the water is separated; A deaerator 450 for further separating COx and O ₂ from the discharge flow B4 'containing hydrocarbons containing n-butane, butene and butadiene condensed in the condensation separator 430; The degassing unit 450, except the added and COx O ₂ separated into high boiling point remover for removing high boiling substances from the exhaust stream (B4 "), including the condensed crude hydrocarbon-in 460; (B4 ''') containing the crude hydrocarbons from which the high boiling point material has been removed is introduced into the purification unit 440.

The n-butane-containing gas excluding the butadiene separated from the purifying section 440 has a discharge flow B7 to be re-introduced into the oxidative dehydrogenation reaction section 410, A gas containing butane except for butadiene joins the fresh butene and is configured to have a discharge flow B8 that is reintroduced into the oxidative dehydrogenation reaction unit 410. [

Added containing the COx and O ₂ separate discharge flow (B6) in the degassing unit 450 is configured such that rotation to the condensation separation unit 430.

The condensate separator 430, a discharge flow (B3) contains a separate COx and O ₂ in can be incinerated.

The condensate separation unit (330, 430) of COx and by the heat generated incinerate O _2, or the heat generated by burning the COx and O ₂ separated by the degassing unit 350 raw material Heat-up (heat up away from the Or between the condensation separators 330 and 430 and the oxidative dehydrogenation reactors 310 and 410 or between the condensate separators 330 and 430 and the deasphalting units 330 and 430 so as to be recycled in the purification units 340 and 440, Heat exchange means may be provided between the condensation separators 330 and 430 and the oxidative dehydrogenation reaction units 310 and 410 and the deaeration units 350 and 450 between the condensation units 350 and 450.

By using the butadiene production method of the present invention and the production apparatus used therein, it is possible to complement the disadvantages of the production method using nitrogen as a diluting gas in a conventional butadiene production process and to increase the treatment effect, Thereby maximizing the energy efficiency. Also, since the butadiene production method of the present invention can be directly used for the purification / manufacture of various materials (ACN, NMP, DMF, etc.) described above, it can be applied to various processes.

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 or scope of the present invention. Such variations and modifications are intended to be within the scope of the appended claims.

[ Example ]

Example  One

Oxygen was 1: 0.9, butene: water vapor = 1: 5, using raffinate-3 having the composition shown in Table 1 below as a raw material, using butane as a diluent gas, , Butene: butane = 1: 4 was obtained by oxidative dehydrogenation reaction. The water was removed from the cooling separator and the condensed water was discharged at a compression discharge temperature of 80 ° C The mixture was pressurized with a two-stage compressor and the hydrocarbons were condensed to 40 ° C using cooling water. The oxidative dehydrogenation reaction product containing the condensed hydrocarbons is removed from the deasphalted portion such as COx and O ₂ and then the high boiling point substance in the condensed crude hydrocarbon is removed from the high boiling point removing agent, DMF was used to obtain butadiene with a recovery of 91.5% and a final degree of 99.5% by weight.

At this time, the discharge flow of the oxidative dehydrogenation reaction section is measured by gas chromatography, and the discharge flows B1, B2, B3, B5, B4 '' and B4 '' 'of the cooling separation section, (AspenPlus) are shown in Table 2 below.

The amount of solvent used in the purification part was 350 ton / hr, and the content of impurities in the solvent recovered in the purification part and the amount of energy used in recovering the solvent are shown in Tables 3 and 4, respectively.

Comparative Example  One

Oxygen was 1: 0.9, butene: steam: 1: 5, and water was used as a raw material using raffinate-3 having the composition shown in Table 1 below, using butane as a diluent gas, An oxidative dehydrogenation reaction product containing butadiene was obtained by oxidative dehydrogenation reaction of a reaction raw material having a molar ratio of butene: butane = 1: 4, and after removal of water from the cooling separation section, The mixture was pressurized with a two-stage compressor and the hydrocarbons were condensed to 40 ° C using cooling water. The oxidative dehydrogenation reaction product containing the condensed hydrocarbons is removed from the deaeration section such as COx and O ₂ and then introduced into the purification section without passing through the high boiling point removal section. DMF is used as the solvent in the purification process, 91.5%, and a final degree of 99.5% by weight of butadiene.

At this time, the discharge flow of the oxidative dehydrogenation reaction section was measured by gas chromatography, and the composition in the discharge flows (B1, B2, B3, B5, B4 ") of the cooling separation section, the condensation separation section and the purification section, (AspenPlus) are shown in Table 3 below.

The amount of solvent used in the purification part was 350 ton / hr, and the content of impurities in the solvent recovered in the purification part and the amount of energy used in recovering the solvent are shown in Tables 3 and 4, respectively.

Furtherance mole% weight% 1-butene 0.00 0.00 Trans-2-butene 43.20 42.77 Cis-2-butene 28.80 28.51 n-butane 28.00 28.72

The reaction part 310 and
The cooling / Condensation separator 330, deaerator 350, and
Refuse refuse (360) Pressure (kg / cm ² g) 1.0 1.0 0.3 10.2 9.0 9.5 4.5 Temperature (℃) 350 350 40 40 15 79 52 Mass flow rate (kg / hr) Reactant B1 B2 B3 B5 B4 '' B4 '' ' Oxygen 12,203 1,945 1,920 1,795 125 - - nitrogen - - - - - - - COx - 4,080 4.025 2,828 1,194 - - water 38,167 46,375 6,627 29 15 - - Light stay * - 3 3 2 2 - - Carbonyl and aldehyde - 73 61 3 11 46 41 1-butene - 210 209 10 One 198 198 1,3-butadiene - 18,755 18,742 901 157 17,683 17,683 n-butane 98,512 98,512 98,501 3,953 382 94,166 94,163 Acetylene - 23 23 One One 21 21 Trans-2-butane 14,264 1,787 1,786 71 6 1,709 1,709 Cis-2-butane 9,510 610 609 23 2 585 585 High boiling point material ** - 283 137 One - 136 4 toluene - - - - - - - DMF - - - - - - - Sum 172,656 172,656 132,644 9,616 1,896 114,545 114,405

The reaction unit 310 and the cooling separation unit 320, The condensation separator 330 and the deaerator 350 Pressure (kg / cm ² g) 1.0 1.0 0.3 10.2 9.0 9.5 Temperature (℃) 350 350 40 40 15 79 Mass flow rate (kg / hr) Reactant B1 B2 B3 B5 B4 '' Oxygen 12,203 1,945 1,920 1,795 125 - nitrogen - - - - - - COx - 4,080 4.025 2,828 1,194 - water 38,167 46,375 6,627 29 15 - Light stay * - 3 3 2 2 - Carbonyl and aldehyde - 73 61 3 11 46 1-butene - 210 209 10 One 198 1,3-butadiene - 18,755 18,742 901 157 17,683 n-butane 98,512 98,512 98,501 3,953 382 94,166 Acetylene - 23 23 One One 21 Trans-2-butane 14,264 1,787 1,786 71 6 1,709 Cis-2-butane 9,510 610 609 23 2 585 High boiling point material ** - 283 137 One - 136 toluene - - - - - - DMF - - - - - - Sum 172,656 172,656 132,644 9,616 1,896 114,545

The low boiling material than the current C4, except COx, O _2: * Light group stay

** High boiling point substances: aromatic hydrocarbons such as benzene, styrene and phenol, butadiene dimer, acetopyrone, benzophenone or anthrequinone

division The
The impurity content (wtppm) in the recovered solvent Final butadiene recovery rate Carbonyl and aldehyde High boiling point material (weight%) Example 1 1.1 0.0 91.5 Comparative Example 1 1.2 51.5 91.5

division Energy usage (Gcal / hr) High boiling point removal tower Refining part Sum Example 1 9 63 72 Comparative Example 1 - 104 104

As shown in Tables 2 to 4, in Example 1 according to the present invention, the content of the high-boiling substance in the discharge flow B4 '' 'charged into the refiner was 4 kg / hr, whereas in Comparative Example 1, The high boiling point content in stream (B4 '') was very high at 136 kg / hr. In Example 1, the content of high boiling point impurities in the solvent recovered by removing the high boiling point material in crude hydrocarbons was lowered in comparison with Comparative Example 1, so that high purity butadiene was obtained while reducing the processing load of the purification portion.

As shown in Table 5, the energy consumption of Example 1 according to the present invention is 72 Gcal / hr, whereas the energy consumption of the first embodiment is 104 Gca / hr. Could.

110, 310, 410: oxidative dehydrogenation reaction unit
120, 320, 420:
130:
330, 430: condensation separator
140, 340, 440:
350, 450:
360, 460: High boiling point remover
431: Compressor
432: heat exchanger

Claims (14)

A process for producing an oxidative dehydrogenation reaction product comprising butadiene, oxygen (O ₂ ), steam, and diluent gas by passing the reaction raw material through an oxidative dehydrogenation reaction unit,
Separating the water while passing the oxidative dehydrogenation reaction product containing the butadiene through the cooling separator,
Passing the oxidized dehydrogenation reaction product separated from the water to the condensation separation unit, condensing the hydrocarbons and separating COx and O ₂ ,
Further separating COx and O ₂ while passing condensed n-butane, butene and butadiene-containing hydrocarbons through the deaeration section in the condensation separation section,
Separating the high boiling point material while passing through the high boiling point remover, the crude hydrocarbons including n-butane, butene and butadiene, which are further separated and condensed with COx and O ₂ in the deaeration section;
Separating the butadiene while passing the crude hydrocarbon from which the high boiling point material has been removed to the refining unit,
Wherein the n-butane and butene-containing gas except for the butadiene separated in the refining unit is re-introduced into the oxidative dehydrogenation reaction unit, and the diluent gas is butane. The method according to claim 1,
Wherein oxygen (O ₂ ) contained in the reaction raw material is introduced in a gas form having a purity of 90% or more. The method according to claim 1,
Wherein the reaction condition in the oxidative dehydrogenation reaction unit is a molar ratio of butene: oxygen: water vapor: diluent gas = 1: 0.5 to 3: 0.1 to 20: 0.1 to 20. The method according to claim 1,
Wherein said condensation separation is a single-stage compression structure of one stage, a multi-stage compression structure of two to ten stages, or multi-stage compression of one or two stages and a compression discharge temperature of 50 to 250 ° C. The method according to claim 1,
The refrigerant used in the condensation separation is at least one selected from the group consisting of cooling water, ethylene glycol, an aqueous solution of ethylene glycol having a concentration of 20 to 100 wt%, propylene glycol, an aqueous solution of propylene glycol having a concentration of 30 to 100 wt%, and a propylene- ≪ / RTI > The method according to claim 1,
Separating the COx and the O ₂ while passing the condensed n-butane, butene and butadiene hydrocarbons to the deaeration section in the condensation separation section,
The method of butadiene according to step to inject the COx and O ₂ separated further from the degassing system into condensate, characterized in that consisting of. The method according to claim 1,
The oxidative dehydrogenation reaction unit reacts with butane, oxygen (O ₂ ), steam, and a gas containing n-butane and butene, which are re-introduced into the oxidative dehydrogenation reaction unit as residues from which butadiene is separated from the purification unit Wherein the ferrite catalyst is used as a raw material and is driven under an isothermal or adiabatic condition at a reaction temperature of 150 to 650 占 폚. The method according to claim 1,
Wherein the cooling separator is driven by a quencher or an indirect cooling method of quenching. The method according to claim 1,
Wherein the deaeration section is driven by stripping or degassing using a general column. The method according to claim 1,
Wherein the high boiling point remover is driven by a distillation method. The method according to claim 1,
Of butadiene, it characterized in that the COx and O _2, or the heat generated by burning the COx and O ₂ separated by the degassing separated in the condensate separation unit is recycled to the raw material heat-up (heat up), or the tablet parts Gt; An oxidative dehydrogenation reaction unit for obtaining an oxidative dehydrogenation reaction product comprising butadiene by oxidative dehydrogenation reaction of a reaction raw material including butene, oxygen (O ₂ ), steam and diluent gas;
A cooling separator for separating water from the oxidative dehydrogenation reaction product comprising the butadiene;
A condensation separator for condensing the hydrocarbons in the oxidative dehydrogenation reaction product containing the butadiene from which the water is separated, and separating COx and O ₂ ;
Degassing adding separating COx and O ₂ in the n- butane, butene and butadiene is condensed hydrocarbons in the condensate separation unit;
A high boiling point agent for separating the high boiling point material from the crude hydrocarbons including n-butane, butene and butadiene, which are further separated and condensed with COx and O ₂ ; And
And a refining unit for separating butadiene from the separated crude hydrocarbons,
Wherein the n-butane and butene-containing gas excluding the butadiene separated from the purification section is re-introduced into the oxidative dehydrogenation reaction section, and the diluent gas is butane. 13. The method of claim 12,
And a discharge flow in which COx and O ₂ separated from the deaeration section are introduced into the condensation system. 13. The method of claim 12,
The heat generated by incineration of the COx and O ₂ separated from the condensation separation unit or the COx and O ₂ separated from the deaeration unit may be heat up or recycled in the purification unit, And a heat exchange unit provided between the oxidative dehydrogenation reaction units.

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