JPH0216291B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for separating and recovering high-yield, high-purity butene-1 from a butane-butene fraction containing isobutylene and butene-1.

Butanes, including isobutylene and butene-1
In order to separate butene-1 from the butene fraction, the _C4 fraction other than butene-1 must be separated and removed by precision distillation, but in this case, isobutylene is very similar to butene-1 in terms of relative concentration. Because of this, high purity butene-1 cannot be separated and recovered simply by distillation. Therefore, in order to separate and recover high-purity butene-1 from a butane-butene fraction containing isobutylene and butene-1, it is first required to almost completely remove isobutylene from this fraction.

Conventionally, a sulfuric acid extraction method has been used to separate isobutylene from a butane-butene fraction. However, this method requires the use of high-grade materials due to the corrosive nature of sulfuric acid, which imposes a heavy economic burden.
Another method for separating isobutylene is adsorption using zeolite, but this method does not sufficiently separate butene-1 and butene-2.

Generally, it is considered to dimerize or polymerize isobutylene by using an acidic catalyst and remove this polymer from the butane-butene fraction by distillation, but usually during this reaction, butene-1 is isomerized and butene-1 is There is a strong tendency for it to be 2. Also butene-1
causes a copolymerization reaction with isobutylene. Therefore, in order to separate and recover butene-1 in high yield, it is necessary to suppress these side reactions as much as possible and increase the amount of isobutylene.

The present invention is characterized in that a butane-butene fraction containing isobutylene and butene-1 is subjected to a reaction with special reaction conditions to lower isobutylene while suppressing the loss of butene-1 as much as possible, and then subjected to a distillation operation. This invention relates to a method for separating and recovering high-yield, high-purity butene-1, in which the ion-exchange resin particles are repeatedly used by regenerating the activity of the ion-exchange resin particles whose activity has decreased. The present invention relates to a method for separating butene-1, which is characterized by the following.

That is, the present invention contains 0.1 to 15 wt% of isobutylene,
A butane-butene fraction containing 10 to 50 wt% of butene-1 was placed in a reaction tower filled with strongly acidic cation exchange resin particles with an average particle size of 0.2 to 10 mm at a temperature of 30 to 100°C and a liquid hourly space velocity of 0.1 to 50 (1/2). hr), isobutylene is low-polymerized by passing it continuously under a pressure of 1 to 50 atmospheres, and after this low polymer is removed by distillation, high purity is obtained by precision distillation of the butane-butene fraction. When producing butene-1, the residual rate of butene-1 (the residual ratio of butene-1 after the reaction to the content of butene-1 in the raw material) during the low polymerization reaction of isobutylene is substantially reduced. At that point, the supply of the raw material butane-butene fraction is stopped, and sec-butanol or a hydrocarbon solution containing sec-butanol is supplied to the reaction column at a temperature of 0 to 120°C and under a pressure that can maintain the liquid phase. High-purity butene-1 can be produced from a butane-butene fraction in a high yield by regenerating the catalytic activity of the ion exchange resin particles and then continuously passing the butane-butene fraction through the reaction column. It relates to a method of separation and recovery.

The starting material used in the present invention is isobutylene.
It is a butane-butene fraction containing 0.1 to 15 wt% and 10 to 50 wt% of butene-1. This raw material is usually obtained from the _C4 fraction produced when petroleum is thermally cracked, steam cracked, or catalytically cracked, and the raw material is usually used after almost completely removing butadiene to, for example, 0.1 wt% or less.

These normally contain isobutylene, butene-1, butene-2, isobutane, and n-butane. If isobutylene is contained in an amount greater than 15 wt%, it will not be used effectively. 1 to 10 wt% of isobutylene and 20 to 40 wt% of butene-1 are preferred.

In the present invention, a C ₄ hydrocarbon mixture obtained by separating butadiene from a C ₄ hydrocarbon fraction obtained by cracking petroleum as a raw material butane-butene fraction is polymerized with an aluminum chloride catalyst to form a liquid or semi-solid polymer. It is preferably employed to use an unreacted C ₄ hydrocarbon mixture in producing the coalescence. Conventional C ₄ with butadiene removed
It is known that a liquid or semi-solid polymer (polybutene) is produced by polymerizing a hydrocarbon mixture using an aluminum chloride catalyst as a raw material and polymerizing isobutylene mainly in a _C4 hydrocarbon mixture.
After this polymerization reaction, the unreacted _C4 hydrocarbon mixture has a reduced isobutylene content, but is still about 1
The content is ~10wt%, especially 2~6wt%. Distilling this unreacted C ₄ hydrocarbon mixture as it is does not yield highly pure butene-1, and this mixture has generally been used as a fuel. In the present invention, it is very preferable to use this unreacted C ₄ hydrocarbon mixture as a starting material.

In addition, in the present invention, as a butane-butene fraction as a starting material, a C ₄ hydrocarbon mixture obtained by decomposing and removing butadiene from a C ₄ hydrocarbon fraction obtained by cracking petroleum and methanol are combined in the presence of an acidic catalyst. The unreacted C ₄ hydrocarbon mixture used in the reaction to produce methyl tert-butyl ether can also be effectively used. A C ₄ hydrocarbon mixture from which butadiene has been separated and methanol are reacted in the presence of an acidic catalyst, such as a strong acid cation exchange resin of the same type as described below when used in the present application, and the isobutylene and methanol in the mixture are reacted to form a methyl-tertiary compound. It is known to produce butyl ether, and the unreacted _C4 hydrocarbon mixture after this reaction still contains about 1 to 10 wt% of isobutylene, which is commonly used as a fuel. This unreacted C ₄ hydrocarbon mixture is also effectively used in the present invention.

In the present invention, a butane-butene fraction as a raw material is further reacted with a C ₄ hydrocarbon mixture obtained by separating butadiene from a C ₄ hydrocarbon fraction obtained by cracking petroleum in the presence of an acidic catalyst. The unreacted C ₄ hydrocarbon mixture from which tert-butyl alcohol is produced can also be used effectively. The C ₄ hydrocarbon fraction from which butadiene has been removed and water are treated with an acidic catalyst such as sulfuric acid, hydrochloric acid,
It is known to produce tertiary-butyl alcohol by hydrating isobutylene in the fraction by reacting it using a cation exchange resin, which will be described later, of the same type as used in the present application. The unreacted mixture in this reaction also contains 1 to 10 wt% of isobutylene, which is normally used as a fuel. This unreacted C ₄ hydrocarbon mixture can also be effectively used in this application.

In the present invention, the above-mentioned raw material butane-butene fraction is used, and this is supplied to a reaction column filled with a strong acid type cation exchange resin described below.

In the present invention, it is possible to cause low polymerization of isobutylene by passing the butane-butene fraction through a fixed bed filled with a strongly acidic cation exchange resin in a one-stage, one-pass system.
However, if this process continues for a long time, the isobutylene polymer will be adsorbed into the ion exchange resin.
A gradual decrease in activity appears. In that case, measures are taken to maintain the removal rate of isobutylene by the low polymerization reaction above a certain value by raising the reaction temperature, but in this case, butene-1 undergoes isomerization and polymerization, and its content gradually decreases. A decreasing trend is observed. The butene-1 produced is maintained at a high purity of, for example, 99% or more, and the residual rate of butene-1 at that time is maintained at a high level, resulting in butene-1.
It is required to maintain a high recovery rate of 1.
If the degree of polymerization of isobutylene gradually decreases after the start of the reaction, the purity of the product will deteriorate. In this case, it is necessary to gradually raise the reaction temperature to maintain the reaction rate of isobutylene at the same level as at the beginning of the reaction (for example, 90% or more, especially 95% or more). More reactions occur concurrently and the residual rate of butene-1 decreases.
In the present invention, the catalyst regeneration operation is carried out when the residual rate of butene-1 after the temperature is raised is reduced to, for example, 80% or less, especially 70% or less, compared to the residual rate of butene-1 at the beginning of the reaction.

The method for regenerating the ion exchange resin of the present invention involves interrupting the flow of the butane-butene fraction, and then
sec-butanol or a hydrocarbon containing sec-butanol is supplied and brought into contact with the resin. It is usually fed from the top or bottom of the reaction column. In this case, the temperature is 0 to 120°C, preferably 20 to 100°C, and the liquid hourly space velocity is usually 0.01 to 50 (1/hr), preferably 0.5 to 10 (1/hr).
hr), generally for 5 minutes to 30 minutes under a pressure that can maintain the liquid phase.
This is accomplished by continuous flow for an hour, preferably 30 minutes to 10 hours, or by temporarily stopping the flow of sec-butanol during this time. Temporary means, for example, about 10 minutes to 3 hours, and this is preferably used when there is sufficient time for reproduction. It is extremely unique that the ion exchange resin catalyst is effectively regenerated by the flow of sec-butanol or a hydrocarbon containing sec-butanol.
sec-butanol may be used alone as is,
It may also be diluted with hydrocarbons. Usually in this case
The concentration of sec-butanol is 1 wt% or more, preferably 30 wt% or more. The hydrocarbon in this case is not particularly limited, but butane, hexane, octane, or saturated hydrocarbons having a larger molecular weight than these are preferable. If sec-butanol or a hydrocarbon containing sec-butanol is at a temperature lower than 0°C, sufficient regeneration will not occur. Setting the temperature higher than 120°C is not preferable because it approaches the allowable temperature limit of the ion exchange resin. Normal liquid space velocity is 0.01 (1/hr)
If it is smaller than 50, it will take too long to play.
(1/hr) or more, waste of sec-butanol, etc. increases. After passing through the ion exchange resin catalyst
If necessary, sec-butanol or a hydrocarbon containing sec-butanol is distilled to separate and remove heavy components dissolved therein, and then used again to regenerate the ion exchange resin catalyst whose activity has decreased. be able to. sec-butanol or a hydrocarbon containing sec-butanol is supplied, and the pressure during contact with the resin may be any pressure as long as the fluid maintains a liquid phase. For example, the boiling point of sec-butanol is 99.5℃
Therefore, when using only sec-butanol,
At temperatures below 99.5°C, almost normal pressure is sufficient. If the flow time of sec-butanol or a hydrocarbon containing sec-butanol is shorter than 5 minutes, the regeneration effect will be insufficient, and if it is longer than 30 hours, the waste of sec-butanol etc. will only increase.

When the butane-butene fraction is passed through a fixed bed filled with the ion exchange resin in the present invention,
Since the low polymerization reaction of isobutylene is an exothermic reaction, a temperature difference occurs between the inlet and the outlet of the reaction tower, and especially when the concentration of isobutylene in the butane-butene fraction is high, there is a temperature difference near the exit of the reaction tower. It gets quite hot. Such high temperatures must be avoided quite strictly from the viewpoint of increasing the loss of butene-1 in the raw material and deteriorating the catalyst. Therefore, in this case, it is necessary to equip the reactor with, for example, a special cooler, but due to the poor heat transfer of the ion exchange resin, a multi-tube cooling reaction type must be used. If this method is adopted, replacing the catalyst becomes complicated. Moreover, even in this case, the presence of localized high-temperature parts often occurs, which is disadvantageous. Therefore, when the reactor is not equipped with a special cooler or the like, the one-stage one-pass method is preferably employed when the content of isobutylene in the butane-butene is 0.1 to 2 wt%. Isobutylene content is 2~
In the case of 15 wt%, the reaction tower is divided into two stages, and in the first reaction tower, the reaction mixture that has passed through the first reaction tower is divided into two streams, and one stream is supplied to the subsequent second reaction tower, It is preferable to adopt a circulation supply system in which the other stream is directly circulated to the first reaction column filled with the ion exchange resin. In this case, the amount of each flow is 1 to 1 for the former and 1 to 15 (times by weight) for the latter (circulating amount), preferably 3 to 7. The second reaction column employs the usual one-pass method. In the case of a circulation system, the temperature within the reaction tower is maintained sufficiently uniform. However, in the one-stage circulation method, the reactivity is lower than in the isothermal one-pass method (piston flow method), so low polymerization of isobutylene can be suppressed, that is, the amount of isobutylene remaining after the reaction with isobutylene in the raw material. is increasing. For this purpose, the reaction conditions must be made harsh (e.g., raising the reaction temperature and lowering the liquid hourly space velocity). However, under such harsh conditions, the amount of loss due to isomerization and polymerization of butene-1 increases, resulting in a decrease in the remaining amount of butene-1. Therefore, in the first stage, it is preferable to adopt a circulation system under conditions where low polymerization of isobutylene is suppressed to some extent (for example, reaction rate of isobutylene, for example, 70 to 90 wt%), and to react the remaining isobutylene in the second stage reaction column. In the second stage, the isobutylene in the second stage raw material is further reduced, and the accumulation of reaction heat is also small, so the temperature difference between the inlet and outlet of the reaction column is small, and the reaction of butene-1 is carried out as much as possible. For the purpose of suppression, the second stage reaction column adopts a one-pass system.

In the present invention, the reaction temperature is 30 to 100° C. regardless of whether it is a one-stage method or a two-stage method.
Preferably it is carried out at 40-75°C. In any reaction tower, if the reaction temperature is lower than 30°C, the reaction rate will be low, resulting in insufficient separation of isobutylene.
Moreover, if the temperature is higher than 100°C, the reaction of butene-1 becomes radical and the amount of loss of butene-1 increases.

The reaction pressure in the present invention is 1 to 50 atm, preferably 50 atm regardless of whether it is a one-step method or a two-step method.
~30 atm. If the reaction pressure is lower than 1 atm, the reaction system will be in a gas phase and the reaction will not be able to reach its full potential.
If the pressure is higher than the atmospheric pressure, the reaction vessel and its attached equipment must be made into strong pressure-resistant equipment, which is industrially disadvantageous.

The strong acid type cation exchange resin as used in the present invention is a cation exchange resin exhibiting strong acidity, and representative examples thereof include styrene sulfonic acid type resin and phenolsulfonic acid type resin. A styrene-based sulfonic acid type ion exchange resin is a sulfonated resin obtained by copolymerizing styrene and a polyunsaturated compound such as divinylbenzene, and is generally represented by the following formula.

Furthermore, the phenolsulfonic acid type resin is usually obtained by condensing phenolsulfonic acid with formaldehyde, and is usually represented by the following formula.

The above-mentioned strong acid type cation exchange resin is used as a catalyst in the present invention, and is used in the form of spherical or cylindrical particles with an average particle size of 0.2 to 10 mm.

The catalyst particles are packed into a pressure-resistant cylindrical reaction vessel to form a bed of a fixed bed.

The size of the fixed bed is not particularly limited.
Usually the height is 0.2m to 20m.

Butane-containing isobutylene and butene-1 from the upper or lower end of the fixed bed, preferably from the upper end.
Continuously feed the butene fraction. The supply amount is such that the liquid hourly space velocity is 0.1 to 50 (Kg/Kg x 1/hr = 1/hr), preferably 0.5 to 15 (1/hr). In the case of a one-stage process, the liquid hourly space velocity referred to here is expressed as the weight of the flow supplied to the reaction column per kilogram of catalyst per hour (hr), and in the case of a two-stage process, it is expressed as the weight of the stream supplied to the reaction column per kilogram of catalyst per hour (hr). hr), the weight (Kg) of the stream fed to the first reaction column per kg of catalyst (excluding the stream circulating through the first reaction column)
In the second reaction column, it is expressed as the weight (Kg) of the flow passing through the second reaction column per 1 kg of catalyst per hour (hr). The supply amount of butane-butene fraction is 0.1 (1/
If it is smaller than hr), the yield of the butane-butene fraction after isobutylene separation will be small, which is industrially disadvantageous. Furthermore, if the feed rate is greater than 50 (1/hr), sufficient separation of isobutylene will not be achieved.

In the present invention, when the isobutylene content in the butane-butene fraction is relatively small, the isobutylene content in the butane-butene fraction can be reduced by lowering most of the isobutylene by a one-step method. If it is relatively large, use a two-stage method to underpolymerize 70 to 90 wt% of isobutylene in the butane-butene fraction of the raw material in the first reaction tower, and underpolymerize most of the remaining isobutylene in the second reaction tower. Removal of isobutylene is accomplished by.

The reaction mixture that has undergone the above reaction is subjected to a distillation column, and heavy hydrocarbons containing mainly isobutylene dimers and low polymers are obtained from the bottom of the column, and light hydrocarbons containing mainly butane-butene are obtained from the top of the column. . For this distillation, it is sufficient to carry out ordinary distillation using about 3 to 30 stages, for example, about 10 to 20 stages.

The light hydrocarbons obtained from the distillation are then further subjected to precision distillation. Usually, this precision distillation is carried out in two stages, and in the first precision distillation, isobutane is mainly separated and removed from the top of the column. The bottom stream is further subjected to precision distillation to mainly remove n-butane and butene-2 from the bottom, and high-purity product butene-1 is produced from the top of the column.
Separate and collect. Precision distillation is usually 30～～
Those with 150 stages, especially around 90 to 140 stages, are used.

When using the method of the present invention, product isobutylene with a purity of 99% or more, and even 99.5% or more can be obtained. Of course, if higher product purity is not required, this can be achieved by making the reaction conditions milder or by relaxing the distillation operating conditions.

In addition, in the present invention, the recovery rate of butene-1 in the raw material (residual rate in the product) is 80% or more, and even 85%.
It is possible to do the above, and it is possible to separate and recover butene-1 with an extremely high yield.

Next, in order to explain the method of the present invention in more detail, an example of the process will be explained with reference to the drawings.

In the case of the one-stage method, in Fig. 1, the butane-butene fraction as a raw material is fed through pipe 1, passed through pipe 3, heated in heater E ₁ , and kept at a predetermined temperature, and then exchanged with strong acid type cations. It enters a fixed bed reaction column R filled with resin particles. The pressure around the reaction tower R is controlled at a predetermined pressure by a pressure control valve PCV. The fluid exiting the reaction tower R passes through the pipe 5, where the pressure is reduced in the PCV, and the temperature is controlled by the heat exchanger E ₂ as necessary, and then the fluid is transferred to the distillation tower D _1.
to go into. A low polymer of isobutylene is separated from the bottom of the distillation column D ₁ , and a butane-butene fraction from which isobutylene has been removed is distilled from the top of the column, which enters the distillation column D ₂ via a line 7 . Isobutane is separated from the top of the column _D2 , and the bottom fraction is sent to the distillation column via line 9.
Enter _D3 . High purity butene-1 is separated from the top of the D ₃ column and the remaining C ₄ fraction is removed from the bottom of the D ₃ column. When the residual rate (or recovery rate) of butene-1 separated from the top of D ₃ via pipe 10 falls below a certain value, the supply of the butane-butene fraction as a raw material is stopped, and the valve is closed. Close V ₁ and V ₄ , open valves V ₂ and V ₃ , feed sec-butanol or a hydrocarbon containing sec-butanol through line 2, and heat it to a predetermined temperature with heater E _{1 via line 3} . It is retained and enters the reaction tower R. The sec-butanol or the hydrocarbon containing sec-butanol used in the reaction tower R to regenerate the ion exchange resin is discharged through a pipe 4. After the end of the playback in the predetermined time,
The supply of sec-butanol, etc. is stopped, valves V ₂ and V ₃ are closed, valves V ₁ and V ₄ are opened, and the supply of the raw material butane-butene fraction is restarted, and the same operation as described above is performed.

Regarding the process of the two-stage method, the distillation system after passing through the reaction tower and the method of regenerating the ion exchange resin whose activity has decreased are the same as the one-stage method, so their explanation will be omitted and a specific explanation of the surroundings of the reaction tower will be given. I do.

In Fig. 2, the raw material butane-butene fraction is fed through pipe 1, passed through pipe 2, heated by heater _E1 , kept at a predetermined temperature, and filled with strong acid type cation exchange resin particles. into the fixed bed reaction column _R1 . The fluid leaving the reaction tower _R1 is divided into two streams, one stream is cooled by a cooler _E2 , then circulated by a circulation pump P, and the raw material is fed from line 1 via line 3. and recycled to the reaction tower _R1 . The other stream of fluid leaving the reaction column _R1 passes through line 4 to the fixed bed reaction column R2, which is maintained at a predetermined temperature by a heat exchanger _E3 and filled with a strong acid type cation exchange resin _. to go into. The pressure around the reaction towers _R1 and _R2 is controlled at a predetermined pressure by a pressure control valve PCV. Fluid exiting the PCV is sent to the distillation system.

Next, the features of the present invention will be described in more detail with reference to Examples.

Example 1 A styrene-based sulfonic acid type ion exchange resin (containing about 20% divinylbenzene, acid amount 4.7 meq/g
Pack 40kg of catalyst (average particle size: 0.5mmφ). Conduit 1
Butane-butene fraction (composition: isobutylene
0.98% (weight, same below), butene-1 29.5%,
Butene-2 (28.9%, isobutane 9.6%, n-butane 31.0%) was fed at a flow rate of 200 kg/hr. The liquid hourly space velocity of the raw material is 5.0 (1/hr). The pressure within the reaction system was maintained at 18 Kg/cm ² G by the operation of the PCV. The inlet temperature of the reaction tower R is controlled by a heat exchanger _E1 to be 48°C. The outlet temperature of the reaction tower R is
At 53°C, the residual rate of isobutylene in the fluid exiting R is 2.8%, and the residual rate of butene-1 is 90.5%.
This fluid passes through pipe 5 and its pressure is reduced in the PCV.
It is fed into distillation column _D1 . A butane-butene fraction with an isobutylene content of 0.03% and a butene-1 content of 26.7% is distilled from the top of the column, and isobutylene oligomers are separated and removed from the bottom of the column. The fraction distilled from the top of distillation column D ₁ is precision distilled in precision distillation columns D ₂ and D ₃ each having 100 theoretical plates, and is passed from the top of D ₃ through pipe 10 to produce butene with a purity of 99.9%. -1 is
Separated at a flow rate of 53.3Kg/hr. Continuous operation is continued while raising the reaction temperature to maintain the purity of butene-1 at 99.8% or higher. After 130 days, the residual rate of butene-1 was below 80%, so we stopped supplying the raw material, and after purging the entire amount of reaction liquid in the reaction system, we closed the valve.
Close V ₁ and V ₄ , open valves V ₂ and V ₃ , and pump sec-butanol through line 2 at 50°C and liquid hourly velocity 2.
(1/hr) for 1 hour under normal pressure. After finishing the supply of sec-butanol, valves V ₂ and V ₃ were closed, valves V ₁ and V ₄ were opened, and the supply of the same raw material butane-butene fraction was restarted, and the catalyst activity returned to the initial activity. He was recovering.

Example 2 In FIG. 2, reaction towers R ₁ and R ₂ were
The same styrene-type ion exchange resin catalyst as
Filling 50Kg and 29.2Kg. Butane-butene fraction (composition: 3.5% isobutylene (same weight below), butene-1 30.1%, butene-2
25.8%, isobutane 9.5%, n-butane 31.1%)
is delivered at a flow rate of 350Kg/hr. The liquid hourly space velocity of the raw material is 7.0 (1/hr). The pressure inside the reaction system is PCV
It is maintained at 18Kg/cm ² G by the operation of . This raw material joins the fluid flowing through the circulation pipe 3 and is sent to the reaction tower R ₁ through the pipe 2. The inlet temperature of the reaction column R ₁ is controlled by a heat exchanger E ₁ to be 50°C. The fluid exiting the reaction tower _R1 is divided into two fluids, and one flow is controlled by a circulation pump P so that the flow rate is five times the raw material charge flow rate (circulation ratio 5).
It passes through pipe 3 and joins the new raw material. The other stream leaving reaction column R ₁ is passed via line 4 to reaction column R ₂ . The residual rate of isobutylene in this fluid is 20.2
%, the residual rate of butene-1 was 90.0%, and the residual rate of butene-1 was 90.0%.
The inlet temperature of R ₂ is controlled by heat exchanger E ₃ to be 50°C. The liquid space velocity at R ₂ is 12
(1/hr). The residual rate of isobutylene in the fluid leaving the reaction tower _R2 is 2.8%, and the residual rate of butene-1 is
85.5%, and this fluid passes through line 5, has its pressure reduced in the PCV, and is sent to distillation column _D1 . A butane-butene fraction with an isobutylene content of 0.098% and a butene-1 content of 25.7% is distilled from the top of the column, and isobutylene oligomers are separated and removed from the bottom of the column. The fraction distilled off from the top of distillation column D ₁ is precision distilled in precision distillation columns D ₂ and D ₃ each having 100 theoretical plates, and is passed through pipe 10 from the top of D ₃ to a purity of 99.6%.
of butene-1 is separated at a flow rate of 90 Kg/hr. Continuous operation is continued while raising the reaction temperature to maintain the purity of butene-1 at 99.6% or higher. After 120 days, the residual rate of butene-1 became 80% or less, so the catalyst in reaction column _R1 was regenerated in the same manner as in Example 1. The reproduction operation is the same as in Example 1, but
The regeneration fluid is a mixed solution consisting of 20wt% sec-butanol, 65wt% n-butane, and 15wt% isobutane, and the regeneration conditions are a temperature of 50°C and a liquid hourly space velocity of 5.
(1/hr), pressure 8 Kg/cm ² , and flow time 3 hours. After the regeneration was completed, the feed of raw material butane-butene was restarted, and the reaction was carried out under the same conditions as in the first half of this example, except that the inlet temperature of reaction tower _R1 was 50°C and the inlet temperature of reaction tower _R2 was 60°C. As a result, the residual rate of isobutylene in the fluid exiting the reaction tower _R2 was 2.8%, and the residual rate of butene-1 was 84.3%, and the effect of regenerating the catalyst in the reaction tower _R1 was sufficiently recognized.

Example 3 In FIG. 2, reaction towers R ₁ and R ₂ of Example 1
30Kg and 22.5Kg of similar catalysts are charged respectively. Obtained by decomposition of petroleum through pipe 1
Butadiene was extracted and removed from the _C4 fraction, which was then subjected to a polymerization reaction using an aluminum chloride catalyst to produce a liquid polymer.Butane-butene fraction, which is an unreacted _C4 fraction (composition: isobutylene 6.0
%, Butene-1 35.3%, Butene-2 32.5%,
180Kg/isobutane 5.9%, n-butane 20.3%)
hr flow rate (liquid hourly space velocity in reaction column R ₁ 6 (1/hr)
The liquid space velocity at R ₂ is 8 (1/hr)). The inlet temperature of the reaction tower _R1 is 47°C, the circulation ratio is 10, and the inlet temperature of the reaction tower _R2 is 50°C. The reaction was the same as in Example 2 except for the above. The residual rate of isobutylene in the fluid passing through pipe 4 is 18.8% and the residual rate of butene-1 is 91.0%, and the residual rate of isobutylene in the fluid passing through pipe 5 is 1.5% and butene-1.
1 survival rate is 85.5%. Isobutylene content 0.09%, butene-1 content 30.2 from the top of distillation column D ₁
% of butane-butene fraction is distilled out, and isobutylene oligomers are separated and removed from the bottom of the column. Butene-1 with a purity of 99.7% is separated from the top of precision distillation column D ₃ via line 10 at a flow rate of 54 kg/hr. Continuous operation is continued while raising the reaction temperature to maintain the purity of butene-1 at 99.7% or higher. After 100 days, the residual rate of butene-1 was below 80%, so Example 2
The catalyst in the reaction column _R1 is regenerated according to the same operation as in the above. However, the difference from Example 2 is that the regeneration conditions are a temperature of 35°C, a liquid hourly space velocity of 8 (1/hr), and a pressure of 5 kg/hr.
cm ² and circulation time of 5 hours. After the regeneration was completed, the feed of raw material butane-butene was restarted, and the reaction was carried out under the same conditions as in the first half of this example, except that the inlet temperature of reaction tower _R1 was 47°C and the inlet temperature of reaction tower _R2 was 59°C. As a result, the residual rate of isobutylene in the fluid exiting the reaction tower _R2 was 1.5%, and the residual rate of butene-1 was 85.0%.
The catalyst regeneration effect was sufficiently recognized.

[Brief explanation of drawings]

1 and 2 are flow diagrams illustrating an example of the process of the present invention. R...Reaction tower, _R1 ...First reaction tower, _E1 ...Heat exchanger,
E ₂ ...Heat exchanger, P...Pump, E ₃ ...Heat exchanger, R ₂
…Second reaction column, E ₄ …Heat exchanger, D ₁ …Distillation column, D ₂
…Precision distillation column, D ₃ …Precision distillation column, V ₁ …Valve,
V ₂ ...Valve, V ₃ ...Valve, V ₄ ...Valve, 1~1
1... Pipeline.

Claims (1)

[Claims] 1 Isobutylene 0.1-15wt%, butene-1 10
Butane-butene fraction containing ~50wt% with average particle size
A reaction tower filled with 0.2 to 10 mm strong acid type cation exchange resin particles was heated at a temperature of 30 to 100°C and a liquid hourly space velocity of 0.1 to 50.
(1/hr), by continuously passing the isobutylene under a pressure of 1 to 50 atm to underpolymerize it, and after removing this underpolymer by distillation, the butane-butene fraction is precision distilled. When producing high-purity butene-1, when the residual rate of butene-1 substantially decreases during the low polymerization reaction of isobutylene, the supply of the raw material butane-butene fraction is stopped and the reaction column is The catalytic activity of the ion exchange resin particles is regenerated by supplying sec-butanol or a hydrocarbon solution containing sec-butanol at a temperature of 0 to 120°C under a pressure that can maintain a liquid phase, and then the butane-butene A method for separating and recovering high-purity butene-1 from a butane-butene fraction in a high yield, the method comprising continuously passing the fraction through the reaction column.