KR20130011565A - Method for preparing isobutene and 1 butene and device therefor - Google Patents

Abstract

PURPOSE: A method and apparatus for manufacturing isobutene and butene-1 is provided to reduce energy for production and to remarkably increase production without extension or change of existing apparatus. CONSTITUTION: A method and apparatus for manufacturing isobutene and butene-1 comprises: an MTBE synthesizing step synthesizing methyl t-butyl ether from an isobutene-containing raw material; a step of collecting isobutene from the methyl t-butyl ether; and a step of separating butene-1 from the extract of the MTBE synthesizing step; and additionally comprises pre-treatment step separating the raw material into low viscosity components and high viscosity components in a fractionating column which is installed in a raw material supply line, and supplying the low viscosity components to the MTBE synthesizing step.

Description

Method for preparing and preparing isobutene and butene-1 {Method for preparing isobutene and 1 butene and Device therefor}

This invention relates to the manufacturing method and manufacturing apparatus of isobutene and butene-1.

The Naphtha Cracking Center (sometimes referred to as the "NCC") is a naphtha produced by refining crude oil as its main raw material, such as pyrolysis, quenching, compression and refining at high temperatures. It is a factory that produces various by-products such as ethylene, propylene and C4 mixed fractions, heavy fuel oil, hydrogen or methane.

The C4 complex process treats methyl tertiary butyl ether (MTBE), isobutene and butene-1 by treating C4 raffinate, a residue of butadiene extracted from C4 mixed fraction produced in a naphtha cracking plant. It is a process to produce butene-1.

Referring to FIG. 1, in the MTBE synthesis process (1), C4 residue oil (C4RAFF), for example, C4 mixed oil produced in a naphtha cracking plant in a BD plant, was used as an extraction solvent using DMF (Diemethyl Formaide) as an extraction material. High-octane-containing oxygen fraction by selectively etherifying isobutene contained in C4 residue, which is the residue after separating and producing 1,3-butadiene by extractive distillation, with methanol in the presence of a catalyst A reaction process for producing phosphorus MTBE and a purification process for separating unreacted C4 residue and high purity MTBE are carried out.

On the other hand, in the isobutene recovery step (2), the MTBE produced in the MTBE synthesis step is decomposed in the presence of a catalyst to separate methanol and a high-purity isobutene recovery step is carried out. In the step, the process of separating the high purity butene-1 in the purification system by selectively hydrogenating (purifying) a predetermined component in the remaining C4 residue oil discharged from the MTBE synthesis process (1), purifying.

An object of this invention is to provide the manufacturing method and manufacturing apparatus of isobutene and butene-1.

The present invention, MTBE synthesis step for synthesizing methyl tertary-butyl ether (MTBE) from a raw material containing isobutene; An isobutene recovery step of recovering isobutene from the methyl t-butyl ether produced in the MTBE synthesis step; And a butene-1 separation step of separating butene-1 from the discharge of the synthesis step of MTBE, the method for preparing isobutene and butene-1, comprising: a fractionation tower installed in a feed line of raw materials supplied to the MTBE synthesis step. The isobutene and butene-1 further comprises a pretreatment step of supplying the raw material, separating the raw material from the low boiling point component and the high boiling point component in the fractionation tower, and feeding the separated low boiling point component to the MTBE synthesis step. It relates to a manufacturing method.

The present invention also relates to an MTBE synthesis apparatus capable of synthesizing methyl t-butyl ether from a raw material comprising isobutene; An isobutene recovery unit capable of recovering isobutene from the methyl t-butyl ether produced in the MTBE synthesis unit; And a butene-1 separation device capable of separating butene-1 from the discharge of the MTBE synthesis apparatus, and is installed in a feed line of a raw material supplied to the MTBE synthesis apparatus, and has a low boiling point component and a high boiling point component from the raw material. And a fractionation column capable of separating and supplying the separated low boiling point component to the MTBE synthesis apparatus.

Hereinafter, the method and apparatus for preparing isobutene and butene-1 will be described in detail.

In one example, the manufacturing method includes a pre-cut tower in a raw material line fed to a C4 complex process for producing MTBE, isobutene and butene-1 from a C4 residue produced in a naphtha cracking plant. Installed to increase the amount of active ingredients to be produced in the downstream feed stream, and also to remove heavy column bottoms in advance to reduce the load on the fractionation tower in subsequent processes to increase production. And a method and apparatus therefor that can reduce the energy required for further production.

According to the method or apparatus, while maintaining the C4 composite process in which the MTBE process, the isobutene recovery and the butene-1 separation process proceeds at the same equipment scale as before, the product yield of isobutene and butene-1 is increased, It saves energy.

The MTBE synthesis step is a step of synthesizing MTBE using a raw material including isobutene, and is typically a reaction process and an unreacted raw material to produce MTBE by selectively etherifying isobutene with methanol in the presence of a catalyst. It can be divided into a purification process for separating high purity MTBE. The raw material including isobutene may be, for example, C4 raffinate, which is a residue after separating 1,3 butadiene from C4 mixed fraction in a BD plant. The isobutene recovery step is a process of decomposing MTBE produced in the MTBE synthesis step in the presence of a catalyst to separate methanol and recovering isobutene of high purity. Since the boiling point difference of the related components in the raw material is not large, and it is not easy to separate isobutene by simple distillation, the isobutene is separated after the synthesis of MTBE once. In addition, the butene-1 separation process may be purified after selectively hydrogenating certain components from the remaining raw materials discharged from the MTBE synthesis process, and the high purity butene-1 is separated from the purification system.

MTBE synthesis step, the recovery step of isobutene and the synthesis step of butene-1, and the equipment for the same are variously known in the art, such methods or equipment is freely in the production method and apparatus Can be applied.

Hereinafter, the method and equipment for the MTBE synthesis step, the recovery step of isobutene, and the synthesis step of butene-1 are exemplarily described, but the method for each step is not limited to the following.

In one example, the MTBE synthesis step may include a first reaction step and a second reaction step, wherein the first reaction step includes a first MTBE reactor, a second MTBE reactor, a MTBE fractionation column, and the like. In the second reaction step may be performed in a device including a secondary reactor in which three catalyst beds are installed.

The reactants subjected to etherification in the first and second MTBE reactors are introduced into the MTBE fractionation tower. In the basic operation, MTBE is classified and produced in the MTBE fractionation column. The top product of the MTBE fractionation column comprises an azeotrope mixture of C4 components and methanol containing unreacted isobutene in the feed, most of which can be sent to the secondary MTBE reactor and the rest to the primary MTBE reactor. At the bottom of the MTBE fractionation tower, a high octane mixture (HOM) can be produced and sent to a storage tank. In addition, in the selective operation, MTBE is produced by being included in the lower part of the MTBE fractionation tower, and may be sent directly to the storage tank due to the pressure difference.

In addition, in the secondary reactor of the MTBE synthesis step, unreacted isobutene is synthesized into MTBE via an etherification reaction, and the effluent of the secondary reactor can be sent to a C4 raffinate fractionation tower, and C4 At the bottom of the residue fractionation tower, MTBE and methanol can be produced and circulated to the primary MTBE reactor.

At the top of the C4 resid fractionation tower, the C4 fraction containing small amounts of methanol is discharged in the form of an azeotrope which can be sent to the methanol removal tower for methanol removal. In the methanol removal tower, methanol is removed together with the process water at the bottom of the tower by countercurrent contact with process water introduced to the upper part of the removal tower, and C4 residue oil from which methanol is removed is produced at the top of the tower. Can be transferred to the butene-1 synthesis step.

In addition, the mixture of water and methanol at the bottom of the methanol stripping tower merges with the flow at the bottom of the tower of the secondary methanol stripping tower and is sent to a methanol water fractionation tower and at the top of the methanol-water fractionating tower. The methanol separated stream is recycled to the primary and secondary MTBE reactors, and water is discharged to the lower portion of the methanol-water fractionation column and recycled to the methanol removal tower.

The stream undergoing the MTBE synthesis step may comprise MTBE, high octane mixtures (HOM) and butenes, and these components may be sent to the MTBE fractionation tower for separation. In normal operation, the raw materials are fed via a feed heater in the MTBE fractionation tower, and the butene components separated at the top of the tower can be condensed in the condenser of the MTBE fractionation tower and then sent to the secondary MTBE reactor. In addition, during high load operation, some or all of the raw materials produced in the secondary MTBE reactor and the C4 resid fractionation tower may be bypassed and sent to the methanol removal tower. After passing through the feedstock heater and gasoline condenser, it can be sent to the MTBE storage tank.

In the MTBE synthesis stage, the gaseous MTBE produced in the side cut at the bottom of the MTBE fractionation column may be introduced into a decomposition reactor and decomposed into isobutene and methanol.

The MTBE decomposition reaction is an endothermic reaction, for example, the reaction may proceed in a reactor consisting of a bundle in which the catalyst is filled in the tube. Effluents after the reaction include unconverted MTBE, isobutene, water, methanol, dimethyl ether and diisobutene and the like, which can be sent to a methanol removal tower for the removal of methanol. Methanol contained in the effluent after the reaction may be removed at the bottom of the column together with water in countercurrent contact with the process water supplied to the top of the methanol removal tower.

The tower top product from which the methanol is removed from the methanol removal tower is sent to an isobutene fractionation column. At the top of the fractionation column, dimethyl ether and isobutene containing saturated water are separated, and at the bottom, unconverted. MTBE, diisobutene may be discharged and circulated to the MTBE fractionation tower for recovery of MTBE.

The mixture discharged from the top of the isobutene fractionation column includes isobutene, water and dimethyl ether. The mixture is transferred to an isobutene purification tower to remove water and dimethyl ether, and high purity isobutene is produced at the top of the purification tower, and isobutene contained in a small amount in the upper effluent of the isobutene purification tower is MTBE. Can be circulated to the reactor.

Butadiene, a raw material for the butene-1 synthesis process supplied in the MTBE synthesis step, contains butadiene. Butadiene has a similar volatility to butene-1 and is not easily separated from butene-1. Therefore, in order to remove the butadiene component from the above, in the synthesis step of butene-1, the C4 residue oil may first be supplied to a selective hydrogenation reactor, and the butadiene may be removed by reacting with high purity hydrogen in the reactor.

After reacting with the C4 residue in the hydrogenation reactor, the remaining excess hydrogen is separated and fed to a light ends fractionation tower to separate propane, dimethyl ether, isobutane, etc. At the bottom of the tower, butene-1, normal butane and butene 2 may be discharged and supplied to the butene-1 fractionation tower. In the butene-1 fractionation tower, butene-1 is produced at the top of the fractionation tower and transported to a tank and stored, and heavy ends (heavy ends) normal butane and butene 2 are discharged from the bottom of the tower and stored in a C4 residue tank. It can be used as a raw material for the hydrogenation process.

2, in the production method of the present invention, the above-described MTBE synthesis step (1); Isobutene recovery step (2); And a fractionation tower (hereinafter, referred to as a "pretreatment fractionation tower") 4 is installed in the feed line of the raw material supplied to the MTBE synthesis step in the butene-1 separation step (3). The raw material of the MTBE synthesis step is first fed. In the pretreatment fractionation column, the raw material is separated into a low boiling point component and a high boiling point component, and the low boiling point component separated therefrom is supplied to the MTBE synthesis step.

A fractionation tower is a facility which separates the multicomponent substance contained in a raw material by each boiling point difference, and is comprised normally as shown in FIG. When the feed (FEED) is introduced into the fractionation tower, the vapor evaporated in the reboiler (1) in the tower rises toward the top (tower) of the tower, the liquid condensed in the condenser (2) is refluxed to It flows downward (bottom) direction. When the vapor and the liquid contact inside the column, the vapor condenses and the liquid evaporates. At this time, the low boiling point component tends to evaporate, and the high boiling point component tends to condense, which leads to the low boiling point component. Concentration increases. This results in a pure low boiling point steam at the top of the separation tower, which is condensed by the condenser 2, partly produced as a product and partly refluxed back to the tower top. On the other hand, the refluxed condensate (reflux) is used to condense the high boiling point components coming up to the bottom. In addition, the high boiling point component discharged from the tower bottom is partly produced as a product, and the other part is evaporated again in the reboiler and then sent to the bottom of the separation tower and used to evaporate the high boiling point component descending from the top of the tower.

In one example, the pretreatment fractionation tower may further include a condenser capable of condensing the upper product of the fractionation tower through heat exchange with cooling water and a reflux drum storing the upper product condensed in the condenser. In addition, the pretreatment fractionation tower may further include a transfer pump for controlling the flow rate of the upper product stored in the reflux drum to be delivered to the product collection drum or recycled to the top of the fractionation tower.

In addition, the pretreatment fractionation tower may further include a cooler capable of cooling the bottom product of the fractionation tower through heat exchange with cooling water, and also a re-composition for heating the bottom product to reflux to the bottom of the fractionation tower. It may further comprise a group.

In one example of the production method, the low boiling point component separated by the pretreatment fractionation tower and supplied to the MTBE synthesis step is a boiling point of about -6.24 ° C under atmospheric pressure among the components contained in the raw material supplied to the pretreatment fractionation tower. It can mean the following components. Such low boiling point components may preferably include isobutene and butene-1, and more preferably at least 80% by weight, more preferably at least 90% by weight, of the low boiling point components separated from the pretreatment fractionation column isobutene. And butene-1. On the other hand, the content of isobutene and butene-1 in the low boiling point component, the higher the value is possible the more efficient subsequent process, the upper limit is not particularly limited.

Meanwhile, the high boiling point component separated from the pretreatment fractionation column may mean a component having a boiling point of 0.5 ° C. or higher under atmospheric pressure among the components contained in the raw material supplied to the pretreatment fractionation column. Such a high boiling point component may include components such as normal butane and butene-2, and may generally contain a large amount of heavy component and the like as compared to the low boiling point component.

Referring to the drawings, an exemplary process for separating the low boiling point components and high boiling point components in the pretreatment fractionation column will be described.

FIG. 4 is a diagram schematically showing equipment in which the pretreatment step is performed.

In the pretreatment process, first, the feedstock, for example, C4 residue oil produced at a naphtha cracking plant, for example, C4 mixed fraction or C4 residue oil in which 1,3-butadiene is separated at a BD plant is classified. It is supplied to (3). In one example, the raw material (FEED) is preferably supplied to the fractionation tower 3 in a preheated state of about 45 ℃ to 80 ℃, preferably 55 ℃ to 63 ℃ in terms of separation efficiency. The method of preheating the raw material (FEED) in the above is not particularly limited, for example, as shown in Figure 4 by installing a heat exchanger (2) in the line supplied with the raw material (FEED), the raw material (FEED) It can be carried out by having the heat exchanger (2) to be supplied to the fractionation tower (3). In one example, the preheating of the raw material may be performed through heat exchange with the condensate of steam condensed through heat exchange with the lower product of the fractionation tower 3 and the FEED supplied to the fractionation tower 3. In this case, an additional energy saving effect can be obtained. In the heat exchange with the condensate, for example, as shown in Figure 4, by controlling the line through which the condensate of steam proceeds through the heat exchanger (2) installed in the supply line of the feed (FEED) Can be done.

In one example of the pretreatment step, the feed of the feed (FEED) to the fractionation column 3 is 0.05 Kg / cm ² g to 0.5 Kg / in comparison to the pressure inside the fractionation column 3 in the normal state of the separation process. cm ² g, preferably 0.1 Kg / cm ² g to 0.3 Kg / cm ² g is preferably carried out at a high pressure, and in the steady state of the separation process, the pressure inside the fractionation column (3) is 5 Kg / cm It is preferable from the standpoint of separation efficiency that it is maintained at about ² g to 9 Kg / cm ² g, preferably about 6.1 Kg / cm ² g to 7.0 Kg / cm ² g. In the above, the pressure inside the fractionation column 3 can be adjusted by adjusting the flow rate of the bypass pipe of the condenser 4 installed in the fractionation column, for example.

When the raw material FEED is supplied to the pretreatment fractionation tower 3, the separation proceeds inside the fractionation tower 3. This separation is, for example, of the top product (typically in the liquid state) produced at the top of the fractionation tower 3 and then cooled back through the heat exchanger and then refluxed back to the top of the fractionation tower 3. It may proceed through equilibrium contact with the bottom product (typically in the vapor state), which is produced at the bottom and passes through the reboiler 11 and back into the bottom of the fractionation tower 3.

Referring to Figure 4 describes the separation process as follows.

As illustrated in FIG. 4, the raw material FEED may be preheated by the heat exchange with the condensate of the steam passed through the reboiler 11 in the heat exchanger 2 and supplied to the pretreatment fractionation tower 3. For example, when the fractionation tower 3 is a tower in which 105 trays are installed, the supply may be supplied at a position between about 44 stages of the fractionation tower. The supplied raw material may be separated by an equilibrium contact action inside the fractionation tower 3.

In the steady state, the upper product of the fractionation tower 3 is condensed, for example, by heat exchange with cooling water in a condenser 4 installed on the upper portion of the fractionation tower 3, and reflux drum 5. Can be stored in. The condensate stored in the reflux drum 5 may be partially conveyed by the pump 6 to the butene collection drum 7, and some may be refluxed to the top of the fractionation tower 3.

In the process, the upper product discharged from the upper part of the fractionation tower 3, that is, the upper product discharged from the upper portion of the fractionation tower 3 and introduced into the heat exchanger 4 is usually in a vapor state, and the temperature is The condensate, which may be from about 53 ° C. to 70 ° C., preferably about 53 ° C. to 62 ° C., and is refluxed to the top of the fractionation column 3 via a heat exchanger 4, is typically in a liquid state and at that temperature. May be 40 ° C to 52 ° C, preferably about 46 ° C to 52 ° C, and can maintain excellent separation efficiency in this range.

On the other hand, as shown in FIG. 4, a part of the lower product of the fractionation column 3 mainly containing heavy components is sent to the cooler 9 by the pump 8 installed at the lower part, and the temperature is lowered from the cooling water. It may be stored in the drum 10 in a down state and then sent to a C4 HTU (C4 Hydrotreating unit) 10.

In addition, a part of the lower part of the pretreatment fractionation tower 3 may be refluxed to the lower part of the fractionation tower 3 while being heated in the reboiler 11 installed at the lower part of the fractionation tower 3 to maintain fluidity. . In the process, the temperature of the bottom product discharged from the bottom of the dividing tower 3, specifically, the bottom product before being introduced into the reboiler 11 is preferably about 66 ° C. to 69 ° C. The temperature of the bottom product flowing into the bottom of the product, ie, the bottom product after passing through the reboiler 11, is preferably 67 ° C to 70 ° C in view of separation efficiency.

On the other hand, steam for heating the bottom product is condensed through the reboiler 11 and collected in the condensate reservoir 12 again. The collected condensate can be transferred to the condensate storage tank 14 by a pump 13 in which heat is exchanged in the line to the condensate storage tank 14 to recover the heat contained in the condensate. Additional energy savings can also be achieved by installing a heat exchanger and exchanging heat with the feed to the fractionation tower.

The low boiling point component separated through the above step may be introduced into the manufacturing process of MTBE as described above and used in the manufacturing process of MTBE, isobutene and butene-1.

The present invention provides a method and apparatus for producing isobutene and butene-1, which can save energy in the manufacturing process of isobutene and butene-1, and can greatly increase the yield of the target product without expanding or modifying an existing apparatus. can do.

1 is a diagram schematically showing a conventional MTBE synthesis step, isobutene recovery step and butene-1 separation step.
2 is a diagram schematically showing the MTBE synthesis step, isobutene recovery step and butene-1 separation step of the present invention.
3 is a schematic diagram showing the form of a general dividing column.
4 is a diagram schematically showing a pretreatment step of the present invention.

Hereinafter, the present invention will be described in more detail through examples according to the present invention and comparative examples not according to the present invention, but the scope of the present invention is not limited to the examples given below.

Example  One

In the C4 complex process line that produces MTBE, isobutene and butene-1, the C4 residue is processed from the C4 mixed fraction produced from the naphtha cracking plant. A pretreatment system as shown in FIG. 4 was installed. In the system of FIG. 4, a fractionation tower 3 having a 105-stage tray was used as the pretreatment fractionation tower 3, and a line was installed to supply C4 residue oil to 44 stages of the fractionation tower. Thereafter, the C4 residue oil is supplied to the fractionation tower 3 to control the separation, and a heat exchanger 2 is installed in the supply line, and the bottom product of the fractionation column 3 is re-boiled in the separation process. After heating at the heat sink), the condensate of the condensed steam and the C4 residue were heat-exchanged, and the apparatus was operated so that the C4 residue was preheated to about 60 ° C. and introduced into the fractionation tower 3. As the C4 residue oil supplied to the fractionation tower 3, C4 residue oil having the composition shown in Table 1 was used, and the C4 residue oil preheated as described above is inside the fractionation tower 3 in which the separation process is performed. The operating conditions were set to be supplied at a pressure of about 0.2 kg / cm ² g higher than the pressure of 6.5 Kg / cm ² g. In the above state, the separation process was performed to separate the low boiling point component and the high boiling point component. At the time of separation, the temperature of the upper product generated at the top of the fractionation tower 3 and before being introduced into the heat exchanger 4 is about 58 ° C., condensed in the heat exchanger 4, and then back to the upper portion of the fractionation tower 3. The temperature of the components to be transferred was adjusted to be about 47 ° C. In addition, the temperature of the bottom product before the introduction into the reboiler 11 generated at the bottom of the fractionation tower 3 at the time of separation is about 66 ° C., and the lower part of the fractionation column 3 is again passed through the reboiler 11. The temperature of the component introduced into was adjusted to be about 70 ℃. The low boiling point component separated through the above process was sequentially introduced into the MTBE synthesis step, the isobutene recovery step, and the separation step of butene-1 to produce a product.

Content (unit: weight%) Flow rate (unit: Kg Of hr ) CH ₄ And C2 Oil 0.05 5.5 C3 Oil 0.09 10.6 i- butane 4.25 484.9 n- butane 16.29 1857.5 One- butene 39.52 4505.2 i- butene 12.14 1383.5 TB -2 17.63 2009.6 CB -2 9.90 112.8 1,2- BD a very small amount 0.1 1,3- BD 0.06 6.4 P.D a very small amount 0.2 C5 + Oil 0.02 2.8 water 0.01 0.6 U. K 0.04 4.2 Unit: wt%
TB -2: trans -2 butene
CB -2: cis -2 butene
BD : butadiene
P.D: propadiene
U.K: Other Ingredients

Comparative example  One

The same conditions as in Example 1 were introduced into the MTBE synthesis step, the isobutene recovery step, and the butene-1 separation step without introducing the C4 residue oil of the composition shown in Table 1, which was used as the raw material in Example 1, without a pretreatment step. Produced the product.

In Example 1 and Comparative Example 1, the MTBE synthesis step, isobutene recovery step and the separation step of butene-1 were analyzed for the content of each component contained in the product, and summarized in Table 2 below.

Example 1 Comparative Example 1 CH ₄ - 0.0175943 C2 oil - 0.0010135 C3 oil 0.17 0.0546935 i-butane 4.91 3.0792347 n-butane 8.06 12.42732 1-butene 32.27 30.580025 i-butene 44.32 33.690651 TB-2 6.34 12.756132 CB-2 3.23 7.0473951 BD 0.33 0.1498954 C ₂ H ₂ 0.0016 0.0041713 P.D 0.058 0.0130016 C5 + oil 0.2 0.0378469 water - 0.001983 U.K 0.1104 0.1390427 Unit: weight%
TB-2: trans-2 butene
CB-2: cis-2 butene
BD: butadiene
PD: propadiene
UK: Other Ingredients

From the results of Table 1, in the case of the present invention, by introducing a pretreatment system without expansion or modification of the existing apparatus, the production of isobutene and butene-1 as targets can be increased, and energy in the manufacturing process You can see that it can reduce the cost.

1: MTBE process
2: isobutene synthesis process
3: butene-1 recovery process
4: pretreatment process

Claims (18)

MTBE synthesis step of synthesizing methyl t-butyl ether from a raw material comprising isobutene; An isobutene recovery step of recovering isobutene from the methyl t-butyl ether produced in the MTBE synthesis step; And a butene-1 separation step of separating butene-1 from the discharge of the synthesis step of MTBE, the method for preparing isobutene and butene-1, wherein the separation tower is installed in a feedstock line supplied to the MTBE synthesis step. The raw material is separated into a low boiling point component and a high boiling point component, and further comprising a pretreatment step of feeding the separated low boiling point component to the MTBE synthesis step. The method for producing isobutene and butene-1 according to claim 1, wherein the low boiling point component is a component whose boiling point under atmospheric pressure is -6.24 ° C or lower. The method for producing isobutene and butene-1 according to claim 1, wherein the low boiling point component comprises isobutene and butene-1. The method for preparing isobutene and butene-1 according to claim 1, wherein the low boiling point component fed to the MTBE synthesis step comprises isobutene and butene-1 in an amount of at least 80% by weight. The method for producing isobutene and butene-1 according to claim 1, wherein the high boiling point component is a component having a boiling point of 0.5 ° C or higher under atmospheric pressure. The method for producing isobutene and butene-1 according to claim 1, wherein the high boiling point component comprises normal butane and butene-2. The method for producing isobutene and butene-1 according to claim 1, wherein the raw material containing isobutene is C4 residue oil produced at a naphtha cracking plant. The method for producing isobutene and butene-1 according to claim 1, wherein the raw material supplied to the fractionation tower in the pretreatment step is supplied in a state of being preheated to 45 ° C to 80 ° C. The method for preparing isobutene and butene-1 according to claim 8, wherein the preheating of the raw material is performed through heat exchange with the condensate of steam condensed through heat exchange with the bottom product of the fractionation column and the raw material supplied to the fractionation column. . The method for producing isobutene and butene-1 according to claim 1, wherein in the pretreatment step, the raw material is supplied to the fractionation column at a pressure of 0.05 Kg / cm ² g to 0.5 Kg / cm ² g higher than the pressure in the fractionation column. The method for producing isobutene and butene-1 according to claim 10, wherein the internal pressure of the fractionation column is maintained at 5 Kg / cm ² g to 9 Kg / cm ² g. 2. The separation of claim 1, wherein the separation within the fractionation tower is produced at the top of the fractionation tower, and is produced at the bottom of the fractionation tower and the top product which is cooled through the heat exchanger and then flows back to the top of the fractionation tower. Method for producing isobutene and butene-1 is carried out through the equilibrium contact with the bottom product flowing through again to the bottom of the fractionation column. The temperature of the upper product discharged from the top of the fractionation tower is 53 ℃ to 70 ℃, the temperature at the time when the product enters the top of the fractionation tower after cooling through the heat exchanger is 40 ℃ to 52 Process for producing isobutene and butene-1, which are degrees Celsius. The method of claim 12, wherein the temperature of the bottom product discharged from the bottom of the fractionation column is 66 ℃ to 69 ℃, the temperature at the time when the bottom product is introduced into the bottom of the fractionation tower through the reboiler is 67 ℃ to 70 ℃ Method for producing phosphorous isobutene and butene-1. MTBE synthesis apparatus capable of synthesizing methyl t-butyl ether from a raw material containing isobutene; An isobutene recovery unit capable of recovering isobutene from the methyl t-butyl ether produced in the MTBE synthesis unit; And a butene-1 separation device capable of separating butene-1 from the discharge of the MTBE synthesis apparatus, and is installed in a feed line of a raw material supplied to the MTBE synthesis apparatus, and has a low boiling point component and a high boiling point component from the raw material. Separation, and isobutene and butene-1 production apparatus comprising a fractionation column capable of supplying the separated low boiling point component to the MTBE synthesis apparatus. 16. The isobutene and butene- according to claim 15, wherein the fractionation tower further comprises a condenser capable of condensing the top product of the fractionation column through heat exchange with cooling water and a reflux drum storing the top product condensed at the condenser. 1, manufacturing apparatus. 17. The preparation of isobutene and butene-1 according to claim 16, further comprising a transfer pump capable of controlling the flow rate of the condensate stored in the reflux drum to be conveyed to the product collection drum or recycled to the top of the fractionation column. Device. 16. The apparatus for producing isobutene and butene-1 according to claim 15, wherein the fractionation column further comprises a reboiler capable of heating the bottom product of the fractionation column to reflux to the bottom of the fractionation column.

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