KR20080023083A - Method of preparing tertiary butanol - Google Patents

Abstract

A method for preparing tertiary butanol is provided to improve the quality of 1-butene by minimizing the content of isobutylene and to allow a catalyst to be used repeatedly. A method for preparing tertiary butanol comprises the steps of contact reacting a hydrocarbon mixture comprising isobutylene and 1,3-butadiene and a heteropolyacid first hydration catalyst aqueous solution under countercurrent at an increased pressure and at an increased temperature to prepare a second hydration catalyst aqueous solution containing tertiary butanol and the residual hydrocarbon; and distilling the second hydration catalyst aqueous solution containing tertiary butanol and the residual hydrocarbon to separate it into tertiary butanol and a third hydration catalyst aqueous solution containing the residual hydrocarbon, wherein the contact reaction is carried out in plural times by using the third hydration catalyst aqueous solution containing the residual hydrocarbon.

Description

Method for producing tert-butanol {METHOD OF PREPARING TERTIARY BUTANOL}

[Industrial use]

The present invention relates to a process for preparing tert-butanol, and more particularly, to a high concentration of tert-butanol by efficiently hydrating isobutylene contained in a residue from which 1,3-butadiene is separated and recovered from a hydrocarbon mixture in the presence of a catalyst. It relates to a method for producing in high yield.

 [Prior art]

The hydrocarbon mixture separated as the cracking product of naphtha contains several hydrocarbon compounds. Among them, industrially useful compounds include 1,3-butadiene, isobutylene, or 1-butene. Of these, 1,3-butadiene has been used as a raw material for synthetic rubber or plastics.

In addition, isobutylene is widely used because butyl rubber, stabilizers of plastics, octane number improvers of gasoline, tert-butanol, methacrylic acid, methacrylic acid esters, and the like can be obtained.

In addition, 1-butene was induced and used with secondary butanol or methyl ethyl ketone together with 2-butene, and recently, the demand for this is gradually expanded to plastic raw materials such as polyolefins. ought.

1-butene, which is used as a plastic raw material, requires a relatively high purity, and in particular, isobutylene should not be mixed. Therefore, a method of separating and recovering 1-butene with high purity from a hydrocarbon mixture having 4 carbon atoms separated from a naphtha decomposition product has been studied.

Generally in the process of separating useful hydrocarbon mixtures from hydrocarbon mixtures separated from naphtha decomposition products, 1,3-butadiene can be obtained by first separating. In this separation process, an optional extraction method using a solvent such as dimethylformamide is used, and according to this process, 1,3-butadiene is separated and removed, and a residue containing almost no 1,3-butadiene is removed. Obtained. Residue, which contains little 1,3-butadiene, is referred to in the art as Spent BB or Raffinate-I (hereinafter referred to as "R-I").

Subsequently, the following two methods may be used to separate and remove isobutylene contained in R-I from the R-I. The first method converts isobutylene to tertiary butyl ether by reacting alcohols, especially RI with methanol, and then separates them. The second method distillates isobutylene by hydrating it to tert-butanol. To remove it. The residue from which isobutylene is recovered and removed according to this process is called Raffinate-II (hereinafter referred to as “R-II”).

When preparing methyl tertiary butyl ether (MTBE) in the first method, there is almost no amount of isobutylene remaining in the final 1-butene, and 1-butene can be distilled off relatively easily. When preparing tert-butanol, it is difficult to separate 1-butene due to the high content of isobutylene in R-II. Also in the second method, it is difficult to separate isobutylene and 1-butene by distillation. Therefore, there is a problem that the content of isobutylene mixed in the obtained 1-butene is high.

The second method is carried out using a catalyst, and two types of catalysts are representatively used. One of them is a sulfuric acid or sulfonic acid compound described in Japanese Patent Application Laid-open No. Hei 8-40956 or Japanese Patent Laid-Open No. 2005-220092, and the other is Japanese Patent Laid-Open No. 58-39134, Japanese Patent Laid-Open No. 2000-44497 Heteropoly acid, such as inmolybdenic acid or phosphotungstic acid, which is a strong acid substance as described in Unexamined-Japanese-Patent No. 2000-44502, etc. are mentioned.

As described above, it is difficult to recover and separate the tertiary butanol produced by hydrating isobutylene from R-II containing a large amount of 1-butene by distillation. In order to solve this problem, Japanese Laid-Open Patent Publication No. 2000-44502 describes the distillation of tertiary butanol by the continuous distillation method, but still has a disadvantage in that it is difficult to completely recover and separate the tertiary butanol.

An object of the present invention is to provide isobutylene present in Raffinate-I (hereinafter referred to as "RI"), which is a residue from which the 1,3-butadiene is selectively recovered from a hydrocarbon mixture separated from a naphtha cracking reaction product. The present invention provides a method for preparing tertiary butanol, which is efficiently hydrated using an aqueous solution of a hydration catalyst to produce a high concentration of tertiary butanol in high yield.

It is another object of the present invention to minimize the isobutylene content remaining in R-II, the residue of which isobutylene is separated and recovered from the RI, with a high yield of high concentration of 1-butene which can be used as a raw material for polyolefins. It is providing the manufacturing method of the tertiary butanol to manufacture.

It is still another object of the present invention to provide a method for preparing tert-butanol, which allows repeated use by reducing the content of tert-butanol from repeatedly used aqueous hydration catalyst solution.

In the present invention, a hydrocarbon mixture containing isobutylene and 1,3-butadiene is subjected to countercurrent contact reaction with an aqueous solution of a first heterohydric catalyst of heteropoly acid under pressure and heating, and then a second aqueous solution of a hydration catalyst containing tertiary butanol and residual hydrocarbons. A method for producing tertiary butanol, comprising the steps of: distilling a second aqueous hydrolysis catalyst solution containing tertiary butanol and residual hydrocarbons to separate tertiary butanol and a third aqueous hydrolysis-containing tertiary catalyst solution; The contacting step provides a method for preparing tert-butanol, which is carried out a plurality of times using the residual aqueous hydrocarbon-containing third hydration catalyst solution.

Hereinafter, the present invention will be described in more detail.

The present invention comprises reacting a hydrocarbon mixture (R-1) comprising isobutylene and 1,3-butadiene with an aqueous solution of a first heterohydric catalyst of heteropolyacid under pressure and heating to countercurrently react to contain tert-butanol and residual hydrocarbons. Tertiary butanol comprising preparing a second aqueous hydration catalyst solution and distilling the second aqueous hydration catalyst solution containing the tertiary butanol and residual hydrocarbons to separate the tertiary butanol from the aqueous solution containing the third hydrocarbon hydride catalyst It relates to a manufacturing method of.

At this time, the tertiary butanol and the residual hydrocarbon-containing tertiary hydration catalyst aqueous solution are completely separated from each other, that is, the tertiary butanol is substantially completely refluxed to recover the contact reaction step. It can be performed multiple times using.

In general, R-1 refers to a residue in which 1,3-butadiene is removed from a hydrocarbon mixture separated from a naphtha decomposition product and thus contains almost no 1,3-butadiene. Although included, it has been described in the present invention to include isobutylene and 1,3-butadiene. However, this does not mean that the 1,3-butadiene is present in the RI in excess .

In addition, the preparation method of the present invention efficiently prepares high-purity tertiary butanol from a hydrocarbon mixture (RI) containing isobutylene and 1,3-butadiene, and at the same time, a hydrocarbon containing isobutylene and 1-butene as by-products. It is possible to minimize the content of isobutylene in the mixture (R-II) and improve the quality of 1-butene which is subsequently separated therefrom.

Next, the production method of the present invention will be described in detail by dividing it into a countercurrent catalytic reaction step and a distillation step.

First, the first object of the present invention is to carry out a countercurrent reaction by reacting a hydrocarbon mixture (R-1) containing isobutylene and 1,3-butadiene of the present invention and an aqueous solution of a heteropolyacid first hydration catalyst under pressure and heating. And a step of selectively hydrating isobutylene in RI to prepare a second aqueous solution of a hydration catalyst containing tert-butanol and residual hydrocarbons, and a second aqueous solution of hydration catalyst containing the residual hydrocarbons (R-II The content of isobutylene remaining in) is minimized. At this time, the isobutylene is hydrated to form tert-butanol.

R-I, the hydrocarbon mixture, is a hydrocarbon mixture obtained by selectively recovering and removing 1,3-butadiene from a hydrocarbon mixture obtained from a product of a naphtha decomposition reaction, for example, a hydrocarbon mixture having 4 carbon atoms.

In the aqueous solution of the first hydration catalyst, any compound called a heteropoly acid may be used as the hydration catalyst, but a heteropoly acid including molybdenum or tungsten as a condensation coordination element may be used. As representative examples thereof, phosphomolybdic acid, phosphotungstic acid or a combination thereof is preferable because of its excellent stability, and phosphotungstic acid has a longer life than phosphomolybdic acid in repeated use of the catalyst.

The concentration of the aqueous solution of the first hydration catalyst is preferably 30% by weight to 75% by weight, more preferably in the range of 40% by weight to 70% by weight. When the concentration of the aqueous solution is less than 30% by weight, the reaction rate is very slow and the yield is lowered. When the concentration of the aqueous solution is more than 75% by weight, the precipitation phenomenon and the reaction rate of the catalyst are not greatly improved, which is not preferable.

In addition, the first hydration catalyst aqueous solution is preferably further containing phosphoric acid can stabilize the catalyst to maintain the activity. The amount of phosphoric acid used is preferably 0.5 to 2.0 parts by weight based on 100 parts by weight of the first aqueous solution of hydration catalyst.

When the phosphoric acid is used in an amount exceeding 2.0 parts by weight, a decrease in reactivity due to an excessive increase in acidity occurs. When the phosphoric acid is used in an amount below 0.5 parts by weight, the reaction rate is lowered, which is not preferable. The most important reason for this problem is the stability of the catalyst. In other words, phosphoric acid stabilizes the catalyst and maintains activity.

In addition, the R-I and the first hydration catalyst aqueous solution is preferably reacted at a mixing ratio of 1: 1 to 5 weight ratio.

At this time, the countercurrent contact reaction is preferably carried out a plurality of times under pressure and heating, more preferably 3 to 5 times.

In the case where the contact reaction is carried out in less than three times, in order to minimize the amount of isobutylene in R-II obtained according to the distillation process, there is a problem in that an excessive amount of the first aqueous hydration catalyst solution for R-I is used. In addition, since the contact reaction is carried out up to five times, the amount of isobutylene can be lowered to a minimum, and thus no further action is required.

The catalytic reaction between the isobutylene and the 1-butene hydrocarbon mixture and the aqueous solution of the first hydration catalyst, that is, the countercurrent catalytic hydration reaction to hydrate the isobutylene to produce tert-butanol is a reversible reaction. Regardless of the type, the equilibrium relationship is constant.

The equilibrium point of theoretical stoichiometry of the reaction can be affected by reaction-temperature.

The reaction is exothermic, and the lower the reaction temperature, the equilibrium point of the reaction may move to the production system. However, the reaction at too low a temperature is difficult to use industrially because the reaction rate is small.

Accordingly, the preferred reaction temperature of the present invention is 30 ° C to 80 ° C, more preferably 40 ° C to 70 ° C.

When the reaction temperature is less than 30 ° C., the rate of hydration reaction is extremely slow, and when it exceeds 80 ° C., a small amount of secondary butanol is produced, which shortens the catalyst life.

In the contact reaction, the contact time is preferably the amount of isobutylene and tertiary butanol almost reaches an equilibrium value, and a short time when the reaction temperature is high, a long time is required when the reaction temperature is low, 0.5 hours to 6 It is preferable that it is time.

According to the process of distilling the tertiary butanol and residual hydrocarbon-containing second hydration catalyst aqueous solution obtained after the countercurrent catalytic reaction, tertiary butanol may be completely distilled and recovered. Residual hydrocarbon-containing tertiary hydration aqueous solution containing tertiary butanol may be used repeatedly. Therefore, it is economical to reuse the expensive aqueous solution of hydration catalyst.

At this time, when the residual amount of tertiary butanol in the residual hydrocarbon-containing tertiary hydration catalyst solution is repeatedly used, the amount of RI and the first hydration catalyst solution (when repeated use, the tertiary hydration catalyst solution) and the number of reactions of countercurrent contact reaction Even if is adjusted, it is difficult to minimize the amount of isobutylene in R-II.

Therefore, in the countercurrent catalytic hydration reaction between RI and the first aqueous solution of hydration catalyst, the final hydration step of isobutylene, that is, in the tertiary butanol content and the R-II in the third aqueous solution of hydration catalyst recovered and reused after the reaction The amount of isobutylene is quantitatively related to each other, which can be calculated simply. However, the equilibrium theoretical discussion of the reaction is accurate only when the reaction system is uniform, and in the reaction system separating the oil layer and the water layer, as in the present invention, only a large number of experimental results are known.

According to many experiments of the present inventors, in the countercurrent hydration reaction of a plurality of stages, the aqueous solution of the hydration catalyst recovered in the final hydration step of isobutylene from RI, that is, the first reuse step of the aqueous solution of hydration catalyst recovered in the reaction, namely The content of tertiary butanol remaining in the residual hydrocarbon-containing tertiary hydration catalyst aqueous solution is 0.2% by weight or less, preferably 0.01% by weight to 0.2% by weight, more preferably 0.01% by weight to 0.1% by weight, and 0.01 to 0.05% by weight. % Is most preferred.

The smaller the content of tertiary butanol, the smaller the better, but in reality it is difficult to reduce to less than 0.01% by weight, so the lower limit is described as 0.01% by weight, but is not limited thereto. When the content of the tertiary butanol exceeds 0.2% by weight, even if the countercurrent catalytic hydration reaction is performed several times in multiple stages, the content of isobutylene in R-II according to the present invention is increased. It is difficult to keep isobutylene at 1.5 parts by weight or less based on 1 part by weight or less and further contained 1-butene l00 parts by weight in R-II.

The minimum content of isobutylene is 1 wt% or less, more preferably 0.1 wt% to 0.7 wt%, and most preferably 0.1 wt% to 0.5 wt% with respect to R-II.

When the minimum content of isobutylene exceeds 0.7% by weight, the amount of tertiary butanol remaining in the R-II remaining after preparing tert-butanol increases and the tertiary butanol is changed to isobutylene by equilibrium. It is difficult to prepare 1-butene in R-II. The reason is that separation is impossible because isobutylene and 1-butene have the same boiling point.

In this regard, a representative composition of RI is 4 in total, 42% by weight of isobutylene, 30% by weight of 1-butene, 15% by weight of 2-butene, 7% by weight of n-butane, 2% by weight of isobutane and other hydrocarbon compounds. Weight percent. When RI of the composition is hydrated and the residual amount of isobutylene in R-II is assumed to be 0.5% by weight, the composition of R-II is 0.5% by weight of isobutylene, 51.5% by weight of 1-butene, and 2- It can be calculated as 25.7% butene, 12% n-butane, 3.4% isobutane and 6.9% by weight in total. Experimental results are similar, and the purity of 1-butene recovered by distillation from R-II is maintained above 99%.

The other hydrocarbon compound refers to a component excluding isobutylene, 1-butene, 2-butene, n-butene, isobutane in RI obtained by removing 1,3-butadiene from a hydrocarbon mixture separated from a decomposition product of naphtha. . These are dozens of hydrocarbon compounds and are not important components in the present invention, so the detailed description thereof will be omitted.

The above ratio is a quantitative relationship with respect to the equilibrium relationship found by many experimental results.

Hereinafter, the distillation process of the present invention will be described in more detail.

According to the countercurrent contact reaction, a second aqueous hydration catalyst solution, which is a residue from which isobutylene is separated and recovered from R-I, is obtained. The second hydration catalyst aqueous solution contains tert-butanol and residual hydrocarbons.

The second aqueous hydrolysis catalyst solution containing tertiary butanol and residual hydrocarbons obtained in the above process is distilled off to separate the third aqueous butanol solution and the residual hydrocarbon containing third hydrolysis catalyst solution. This process corresponds to the second task of the present invention to efficiently obtain a high concentration of tert-butanol and to minimize the amount of tert-butanol remaining in the residual aqueous hydrocarbon-containing tertiary hydration catalyst solution to be recovered.

The catalyst is distilled from a second aqueous hydration catalyst solution containing tertiary butanol and residual hydrocarbons having completed hydration reaction to obtain a high concentration of tertiary butanol and at the same time the amount of tertiary butanol remaining in the aqueous hydration catalyst solution is determined. It is difficult to reduce to the extent that the task is satisfied.

The reason is that in order to solve the above problems, an excessive rectification tower and an excessive reflux ratio for operating the apparatus are required and there is no advantage in terms of construction cost and thermal efficiency of operation.

In the present invention, the above problem can be solved by two methods by performing a two-step distillation process in which distillation of tertiary butanol is carried out in two steps from an aqueous solution of a second hydration catalyst containing tert-butanol and residual hydrocarbons.

In the first method, in the first stage, a distillation solution of the second hydration catalyst containing tert-butanol and residual hydrocarbon is distilled to the extent that a high concentration of tert-butanol is obtained at the top of the distillation column, and the residual hydrocarbon-containing agent discharged from the bottom of the distillation column. A small amount of tertiary butanol remaining in the aqueous solution of the three hydration catalysts is distilled by a two-stage distillation, and the relatively low concentration of tert-butanol obtained at the top of the distillation column in two stages is returned to the first distillation column and discharged from the bottom of the distillation column. This method minimizes the amount of tertiary butanol remaining in the aqueous solution of hydration catalyst.

At this time, the tert-butanol is converted to isobutylene according to the heating process during distillation.

The two-stage distillation process can be designed and carried out in a continuous and batch type of distillation, but in large-scale industrial production, it is preferable to carry out a number of, for example, using a facility in which two distillers are connected in series. Do.

In the second method, tertiary butanol obtained from the second aqueous solution of hydration catalyst containing tert-butanol and residual hydrocarbon is distilled to a high concentration range, and remains in the aqueous solution of the residual hydrocarbon-containing third hydration catalyst discharged from the bottom of the distillation column. Tertiary butanol is a method of heating to isobutylene.

As described above, tert-butanol obtained by a plurality of countercurrent catalytic hydration reactions isobutylene contained in R-I can be separated and recovered from the aqueous hydration catalyst solution by distillation.

The distillation process may be generally carried out under a reduced pressure of 100 hPa to 500 hPa.

If the distillation process is carried out at a pressure of less than 100 hPa, the operation temperature is low, which prevents the decomposition reaction of isobutylene of tert-butanol by reverse reaction. However, the distillation tower or condenser of the distillation equipment used in the distillation process by excessive pressure reduction is preferable. Is too large, which is not an advantage.

In addition, when the distillation step at a pressure of more than 500 hPa is performed, the operation temperature is also high, the decomposition reaction is accelerated to isobutylene of tert-butanol, and the life of the catalyst is shortened, which is not preferable.

In the industrial practice of the present invention, distillation is carried out during a plurality of countercurrent catalytic hydration reactions of the first aqueous hydrolysis catalyst and RI, and the high concentration of tertiary butanol from the second aqueous hydrolysis catalyst solution containing tertiary butanol is distilled. A two stage distillation process is required.

The two-stage distillation process can be carried out by designing a number of distillation ratios in two types, either continuous or discontinuous, but from the viewpoint of economics of operation, it is preferable to design a number of distillers continuously. This is preferable because the processing capacity can be designed equally.

In particular, in the continuous distillation process of tertiary butanol from the aqueous hydration catalyst solution based on this aspect, it is most preferable to use a distillator connected in series in two stages. In addition, this two-stage distillation step is preferably carried out by connecting a plurality of distillers in series continuously. At this time, the plurality of stills is preferably two or more stills.

This is to minimize the content of the residue obtained by extracting isobutylene several times from R-I according to the present invention, that is, isobutylene in R-II.

In this regard, conventionally, studies for minimizing the content of isobutylene in R-II, that is, reducing isobutylene content in the residue of R-II in repeated use of a catalyst or distillation column in the use of a distillation process Minimizing the content of tertiary butanol in the bottom of the aqueous solution of the residual hydrocarbon containing tertiary butanol while maintaining the tertiary butanol at a high concentration has not been studied. Thus, two countercurrent catalysis reactions have been carried out. It was difficult to suppress the content of isobutylene in -II to 3 wt% or less. As a result, it was also difficult to obtain high purity 1-butene.

In the present invention, in order to solve this, the countercurrent contact reaction was carried out three to five times.

When the number of countercurrent catalytic hydration reactions is less than 3, the content of isobutylene remaining in R-II within the range of the ratio of the RI and the aqueous hydration catalyst aqueous solution and the reaction conditions, which is usually carried out, is within the scope of the present invention. In order to minimize the amount of isobutylene in R-II obtained by the distillation process, there is a problem in that an excess amount of the first aqueous hydration catalyst solution for RI is used. In addition, since the contact reaction is carried out up to five times, the amount of isobutylene can be lowered to a minimum, and thus no further action is required.

The countercurrent catalytic hydration reaction between the aqueous hydrolysis catalyst and R-I can be carried out in a pressurized installation where both must be liquid together.

In addition, R-I and a hydration catalyst aqueous solution can be sufficiently mixed for the purpose of densifying contact between the hydration catalyst aqueous solution and R-I.

At this time, reaction temperature is 30 degreeC-80 degreeC, More preferably, it is 40 degreeC-70 degreeC.

In each step, the contact time between RI and the aqueous solution of the hydration catalyst is preferably about the equilibrium value of isobutylene and tert-butanol, short time when the reaction temperature is high, and long time when the reaction temperature is low. , 0.5 hours to 6 hours is preferable.

Since R-I or R-II and the aqueous solution of the hydration catalyst are separated into two layers when left to stand, it is easy to obtain each.

The countercurrent contact reaction reacts in a reaction vessel by colliding a first material stream flowing from one side to another and a second material stream flowing in an opposite direction to the first material stream, so that a specific material is first or different depending on its inherent solubility. It is a reaction that is dissolved in a second class of substances and extracted a lot from one side or the other from the reaction vessel. The continuous countercurrent hydration device for its reaction can be employed in two ways.

One is a facility in which a reactor equipped with a stirrer and a vessel for separating after standing are alternately installed and combined as necessary for the reaction. R-I and an aqueous solution of a hydration catalyst may be subjected to countercurrent contact reaction.

The other is a device similar to a continuous countercurrent extractor, in which an aqueous solution of a heavy hydration catalyst is injected from the upper part of the device, a hard liquid RI is injected from the lower part of the apparatus, and the two liquids are mixed in a sufficient contact. Can be.

In this way, R-I or R-II from which isobutylene has been removed is discharged from the upper portion of the apparatus, and from the lower portion of the apparatus, a residual hydrocarbon-containing third hydration catalyst aqueous solution containing a small amount of tertiary butanol is discharged.

The discharge of the two liquids is automatically performed by using the difference in specific gravity, and at the same time, the ratio between the R-I and the hydration catalyst aqueous solution remaining in the apparatus can be kept constant.

The former has the advantage of easy device design and the ability to change the hydration temperature of each step, but the operation is rather complicated.

On the other hand, the latter design is somewhat complicated, but operation is easy once the conditions are set.

At the time of operation of the equipment, the third aqueous hydration catalyst solution obtained by distilling high concentration of tert-butanol lacks water consumed for hydration of isobutylene and water contained in high concentration of tert-butanol. Therefore, it is necessary to replenish insufficient water for repeated use of the third aqueous solution of hydration catalyst.

The replenishment of water may be continuously input from the outside, and may be accurately performed while measuring the specific gravity of the third aqueous hydrolysis catalyst solution using a hydrometer. At this time, the specific gravity of phosphotungstic acid of 65% by weight is 2.22. In the following, specific examples, comparative examples, and reference examples will be described and described in order to clarify the present invention. However, the embodiments have been described with respect to the discontinuous method so that the description is clear and easy to understand, and this does not limit the present invention.

( Example  One)

Example  1-1

42 weight percent isobutylene, 30 weight percent 1-butene, 15 weight percent 2- in a 20,000 ml stainless steel autoclave with a stirrer, thermometer, pressure gauge, liquid inlet and outlet at the bottom 4,338 g of RI, 4% by weight of butene, 7% by weight of n-butane, 2% by weight of isobutane, and other hydrocarbon mixtures was press-fitted. While mixing this, the temperature in a reactor was 60 degreeC.

Into the reactor, an aqueous solution of a hydration catalyst consisting of 9,100 g of phosphotungstic acid, 91 g of phosphoric acid at 85% by weight, and 4,809 g of water was injected at a rate of 673.9 g per minute while maintaining the temperature of the stirrer at 60 ° C. Thereafter, the reaction was stirred for 30 minutes, and then the stirrer was stopped and allowed to stand for 30 minutes.

Only the hydration catalyst aqueous layer separated in the reaction process was carefully discharged, and the hydration catalyst aqueous solution obtained by repeating the above process three times was stored in a container with a sealed inner volume of 10, OOml using the aqueous hydration catalyst aqueous solution three times.

Remaining in the reactor was a hydrocarbon designated R-I 'in which isobutylene was hydrated once from R-I.

While mixing the hydrocarbon (R-I ') remaining in the reactor, while maintaining the reactor at 60 ℃, the same aqueous solution of the hydration catalyst prepared previously was pressed at the same rate.

Thereafter, the mixture was mixed for 30 minutes under the same conditions as the above reaction, and allowed to stand for 30 minutes to repeat the step of discharging the lower aqueous solution of the hydration catalyst twice. It was stored in a container of 10,000m1 enemy.

Remaining in the reactor was a hydrocarbon designated R-I '' in which isobutylene was dehydrated once more from R-I '.

While mixing this again, while maintaining the reactor at 40 ° C., the same aqueous hydrocatalytic solution prepared previously was press-fitted at the same rate. Then, after mixing for 90 minutes, it was left to stand for 30 minutes.

The aqueous solution of the hydration catalyst obtained by discharging the lower aqueous solution of the hydration catalyst was stored as a one-time use hydration catalyst aqueous solution in a container having an internal volume of 10, OOm1.

The hydrocarbon mixture left in the reactor was called R-II, taken out of the vessel cooled to −10 ° C., and its composition was analyzed.

The analysis yielded 0.28% isobutylene, 51% 1-butene, 26% 2-butene, 12% n-butane, 3.6% isobutane and 7% other hydrocarbon compounds.

1250 g of the aqueous solution of the above-used hydration catalyst and 1,250 g of pure water were charged into a 15,000 m1 hard glass still with a thermometer and an effective stage of about 20 stages of a packed distillation column.

The upper part of the distillation column was equipped with a precision thermometer, a cooler, and a device with varying reflux ratio. In addition, the cooler was connected to a vacuum machine, and the distillation operation was performed reliably under a reduced pressure of 200 hPa.

The reflux ratio is the ratio of the quantity of water discharged to the outside of the distiller after cooling, and the quantity of water entering the distiller again. The distillation starts at 1 to 7 parts by weight. Changed. Subsequently, fractions (fractions) were obtained until the temperature at the top of the distillation column reached 59 ° C. at the same reflux ratio as that of the second receiver.

However, in the distillation after the initial stage, since the temperature in the distillation rose with the increase of the concentration of the aqueous solution of hydration catalyst, pure water was replenished appropriately.

The concentration of tert-butanol in the first receiver was 82% by weight, yielding about 2500 g.

The concentration of tertiary butanol in the second receiver was 23% by weight and about 1,100 g was obtained.

This was preserve | saved in the container as dilute tertiary butanol.

Since the excess amount of the hydration catalyst aqueous solution remaining in the distillation machine was concentrated, it was adjusted to the same specific gravity as the hydration catalyst aqueous solution prepared by replenishing pure water and stored in the container as the regeneration hydration catalyst aqueous solution.

The tertiary butanol content in the obtained regenerated hydration catalyst aqueous solution was 0.039 wt%.

Example  1-2

4,338 g of R-I was injected into the reactor used in Example 1-1. The temperature in a reactor was 60 degreeC, mixing this. Here, 86 g of pure water was added to the double-use hydration catalyst aqueous solution preserve | saved in Example 1-1, and it pressed in to the reactor, maintaining the temperature of 60 degreeC at the rate of 673.9 g per minute similarly to Example 1-1.

After mixing for 30 minutes after that, the mixture was left for 30 minutes, and only the aqueous hydration catalyst solution was discharged and stored in an aqueous hydration catalyst solution for three uses.

Subsequently, the inside of the reactor was kept at 60 ° C., and the mixture of the first-use hydration catalyst solution of Example 1-1 was pressed at the same rate and mixed for 30 minutes, followed by standing for 30 minutes.

Subsequently, only the aqueous hydration catalyst solution obtained by discharging only the aqueous hydration catalyst solution was stored as a two-use hydration catalyst aqueous solution.

While maintaining the temperature in the reactor at 40 ° C, the regeneration hydration catalyst aqueous solution of Example 1-1 was press-fitted in the same manner as in Example 1-1, mixed for 60 minutes, and left to stand for 30 minutes.

The hydration catalyst aqueous solution was discharged, and the obtained hydration catalyst aqueous solution was stored as a single use hydration catalyst aqueous solution.

The isobutylene content in R-II left in the reactor was 0.32% by weight.

The dilution tert-butanol and pure water 400g of Example 1-1 were added to the said three times use aqueous solution of hydration catalyst, and it carried out similarly to the distillation operation of Example 1-1, about 2,900g and 25 weight of high concentration tert-butanol of 82 weight% About 1,000 g of dilute tert-butanol in% was obtained.

In other words, about 2,900 g of 82% by weight tert-butanol was equivalent to the theoretical amount obtained from R-I used.

Pure water was added to the hydration catalyst aqueous solution left in the still, and the concentration was adjusted, and stored as a regeneration hydration catalyst aqueous solution.

The tertiary butanol content in the obtained regenerated hydration catalyst aqueous solution was 0.043 wt%.

Example  1-3

In the same manner as in Example 1-2, 86 g of pure water was added to the double-use hydration catalyst aqueous solution obtained in Example 1-2, and then press-fitted at a temperature of 60 ° C. in RI injected into the same reactor as in Example 1-2. .

Thereafter, the same operation as in Example 1-2 was performed using the once-use and regenerated hydration catalyst aqueous solution.

Content of the isobutylene of R-II obtained here was 0.31 weight%.

Dilution tert-butanol obtained in Example 1-2 and 500 g of pure water were added to the aqueous hydration catalyst solution used three times and distilled under the same conditions as in Example 1-2, and 82 wt% of tertiary butanol was about 2,900 g and 25 wt% Approximately 1,000 g of tertiary butanol was obtained.

Pure water was added to the aqueous solution of the hydration catalyst left in the distillation to adjust the concentration.

The tertiary butanol content in the obtained regenerated hydration catalyst aqueous solution was 0.036 wt%.

That is, Example 1 was carried out continuously, but in Example 1-3 it was confirmed that the storage state is completely, the same result was obtained.

( Comparative example  One)

Three times the hydration catalyst aqueous solution used in the same manner as in Example 1 was injected into the still used in Example 1, and the reflux ratio is the ratio of the quantity of water discharged to the outside of the distiller after cooling under the same conditions and the quantity of water entering the distiller again. When distilled by weight, that is, without reflux, a large amount of outflow was required to limit the content of tert-butanol in the aqueous solution of hydration catalyst to 0.05% by weight or less, and pure water must be replenished several times with distillation during distillation.

The concentration of tertiary butanol obtained here was 31% by weight, and distillation was necessary again to obtain a high concentration of tertiary butanol.

As described above, the present invention uses a catalyst which can be repeatedly used, efficiently produces high concentration tert-butanol from RI, and simultaneously minimizes the content of isobutylene in by-product R-II. Therefore, there is an effect of improving the quality of 1-butene separated.

Claims (21)

A hydrocarbon mixture comprising isobutylene and 1,3-butadiene was reacted countercurrently under pressure and heating with an aqueous solution of heteropolyacid first hydration catalyst to prepare a second aqueous hydration catalyst solution containing tert-butanol and residual hydrocarbons. ; A method for producing tertiary butanol comprising distilling a second aqueous hydrolysis catalyst solution containing tertiary butanol and residual hydrocarbons to separate tertiary butanol and a third hydrocarbon containing aqueous solution. The contact reaction step is a method for producing tert-butanol, which is carried out a plurality of times using the residual aqueous hydrocarbon-containing third hydration catalyst solution. The method of claim 1, The residual hydrocarbon-containing tertiary hydration catalyst aqueous solution comprises a tertiary butanol of 0.2% by weight or less. The method of claim 2, The residual hydrocarbon-containing third hydration catalyst aqueous solution comprises 0.01 to 0.2% by weight of tertiary butanol. The method of claim 2, The residual hydrocarbon-containing third hydration catalyst aqueous solution comprises 0.01 to 0.1% by weight of tertiary butanol. The method of claim 2, The residual hydrocarbon-containing third hydration catalyst aqueous solution comprises 0.01 to 0.05% by weight of tertiary butanol. The method of claim 1, The residual hydrocarbon-containing third hydration catalyst aqueous solution is isobutylene is a method for producing tert-butanol, the content of 1% by weight or less. The method of claim 1, The residual hydrocarbon-containing third hydration catalyst aqueous solution is a method for producing tert-butanol containing 0.1 to 0.7% by weight of isobutylene. The method of claim 1, The first hydration catalyst aqueous solution is a method for producing tert-butanol having a concentration of 30% by weight to 75% by weight. The method of claim 1, The method for producing tert-butol, wherein the hydrocarbon mixture including isobutylene and 1,3-butadiene and the aqueous solution of the first hydration catalyst are reacted at a mixing ratio of 1: 1 to 5 weight ratio. The method of claim 1, Wherein said heteropolyacid is selected from the group consisting of inmolybdic acid, phosphotungstic acid, and combinations thereof. The method of claim 1, And said hydrocarbon mixture is obtained by selectively recovering 1,3-butadiene from a hydrocarbon mixture obtained from a product of a naphtha decomposition reaction. The method of claim 1, The residual hydrocarbon-containing second hydration catalyst aqueous solution is a residue of isobutylene separated from the hydrocarbon mixture containing the isobutylene and 1,3-butadiene and recovered. The method of claim 1, The catalytic reaction process is a method for producing tert-butanol which is carried out for 0.5 to 6 hours. The method of claim 1, The contact reaction is a method for producing tert-butanol which is carried out at 30 ℃ to 80 ℃. The method of claim 1, The contact reaction is a method for producing tert-butanol which is carried out 3 to 5 times. The method of claim 1, The distillation step is a method for producing tert-butanol carried out under reduced pressure of 100 hPa to 500 hPa. The method of claim 1, The residual hydrocarbon-containing third hydration catalyst aqueous solution is a method for producing tert-butanol which is repeatedly used in the distillation process. The method of claim 1, The distillation step is a method for producing tert-butanol which is carried out in two steps. The method of claim 1, The distillation process is a method for producing tert-butanol, which is carried out by designing the distillator in a continuous or batchwise manner. The method of claim 19, The distillation process is a method for producing tert-butanol which is carried out by designing a distillation in a continuous manner. The method of claim 20, The distillation step is a method for producing tert-butanol which is carried out by connecting a plurality of distillers in series in series.