JP2002154999A - Method and apparatus for producing chlorohydrin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus by which selectivity of chlorohydrin is increased and the chlorohydrin is industrially advantageously produced. SOLUTION: The chlorohydrin can be obtained with high selectivity by carrying out at least one time of an operation of making a chlorine-dissolved aqueous solution flow in a passage of a tubular reactor, supplying an olefin gas to the chlorine-dissolved aqueous solution in the passage and mixing the both at a static mixer and collecting the obtained aqueous solution of chlorohydrin without circulating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a novel method and apparatus for producing chlorhydrin. More specifically, the present invention provides a method and an apparatus for producing chlorohydrin with high selectivity using chlorine and olefin as raw materials in an aqueous solvent.

[0002]

2. Description of the Related Art Chlorhydrins such as ethylene chlorohydrin, propylene chlorohydrin and propylene dichlorohydrin are important compounds as raw materials for producing epoxy compounds such as ethylene oxide, propylene oxide and epichlorohydrin.

[0003] The chlorohydrin is generally produced by reacting an olefin with chlorine in water.

However, in the above reaction, chlorine is added to the double bond of the olefin to form an olefin dichloride, or to prevent side reactions such as formation of ethers by a sequential reaction. Reaction conditions in which the reaction is carried out at a low temperature are generally employed. (M
M. P. Ferreo et al., Industry Chm
iq Beige 19 pages 113 pages 1954
Year).

Heretofore, the above reaction conditions have been realized by using a reactor called a so-called chlorohydrin column. That is, olefin as a raw material is supplied from the lower part of the U-tube reactor with which the upper part communicates, and a large amount of water is circulated using a gas lift by bubbles as a main driving force, and a small amount of chlorine is reduced in a downward flow region. A method for producing chlorohydrin while supplying chlorine and chlorhydrin at low concentrations by supplying the chlorohydrin at a low rate has been widely practiced. (Published by Nikkan Kogyo Shimbun; Nikkan Kogyo Gijutsu, 14 propylene-based petrochemicals, pp. 106-110).

[0006] Further, a tubular reactor and a gas-liquid separator each having a chlorine gas supply port and an olefin supply port in the flow path in succession, and a static mixer provided at a downstream position of the supply port, respectively. The rear end opening of the tubular reactor is connected to a gas-liquid separator, and the reaction solution separated by the gas-liquid separator is supplied to the front opening of the tubular reactor via a circulation pump. Using a reactor that formed a circulatory system by replenishing water,
A method has also been proposed in which a part of the liquid phase of the gas-liquid separator is taken out to obtain an aqueous chlorhydrin solution. (The specification of the People's Republic of China published patent No. 123201).

[0007] Among the above-mentioned methods, the method using a chlorhydrin column has been conventionally and industrially widely practiced because of its simple structure. However, a large amount of water is used to suppress the formation of by-product olefin dichlorides, and it is necessary to circulate a large amount of the reaction solution. And the volume efficiency of the apparatus is low.
Further, there is still room for improvement in the chlorohydrin selectivity of the target product.

On the other hand, in the method of forming a circulation system using a tubular reactor, although the volumetric efficiency of the reactor is high, the chlorohydrin selectivity of the desired product can always be satisfied, as in the method using the chlorohydrin column. It was not something.

[0009]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for producing chlorohydrin by reacting chlorine and an olefin in water to increase the selectivity of chlorohydrin and to produce chlorohydrin industrially advantageously. It is an object of the present invention to provide a method and an apparatus.

[0010]

Means for Solving the Problems As a result of repeated studies to achieve the above object, the present inventors have made a chlorine-dissolved aqueous solution flow through the flow path of a tubular reactor, The operation of mixing the olefin with the flow of the aqueous chlorine solution by a vessel is performed at least once in series, and the obtained reaction solution is taken out without being circulated, and the chlorohydrin aqueous solution is recovered to obtain a reaction solution having a high chlorohydrin concentration. The present inventors have found that chlorohydrin can be produced with a higher selectivity than the above-mentioned technology employing the conventional circulation system, and have completed the present invention.

That is, according to the present invention, at least one operation of flowing an aqueous chlorinated solution through a channel of a tubular reactor and supplying an olefin gas to the aqueous chlorinated solution and mixing the olefin gas with a static mixer in the channel is provided. It is intended to provide a method for producing chlorhydrin, wherein the method is carried out more than once, and the obtained aqueous solution of chlorohydrin is taken out without being circulated.

Further, according to the present invention, as a preferred apparatus for carrying out the above method, a static mixer is provided in a flow path and a gas supply port is provided in an upstream flow path of the static mixer. A water supply port is provided at a front end of a flow path of the tubular reactor, and at least one unit including at least two static mixers is provided in the flow path. The chlorine gas supply port is provided in the stationary mixer located on the upstream side, and the olefin gas supply port is provided in the stationary mixer located on the downstream side, and an outlet for recovering the aqueous chlorohydrin solution is provided at the rear end of the channel. An apparatus for producing chlorhydrin is provided.

[0013]

DETAILED DESCRIPTION OF THE INVENTION In the present invention, the reaction between chlorine and olefin in an aqueous medium is carried out using a tubular reactor. That is, in the method of the present invention, the olefin gas is sequentially supplied to the channel of the aqueous solution of chlorine solution once or several times in a divided manner, while preventing the liquid after mixing the olefin gas from mixing with the previous liquid. The concentration of chlorhydrin, which is a product in the flow channel, is increased stepwise, and the resulting reaction solution is taken out without circulation, and it is essential to use a tubular reactor.

Therefore, the tubular reactor is not particularly limited as long as it constitutes a tubular channel having no circulation channel.

In the present invention, in the above tubular reactor, the mixer provided for mixing the olefin gas or, if necessary, the chlorine gas into the aqueous solution flowing through the flow path is a static mixer. The use is important in order to promote rapid dissolution of these gases in an aqueous solution and to be able to obtain a target product with high selectivity.

As the above-mentioned static mixer, a known commercially available mixer can be used without any limitation. Specifically, an ejector, a plate-type or cup-shaped collision plate type static mixer, and Kenics type, Sulzer type, Etoflo type,
Tray Hi-mixer type, Bran & Lubbe type, N-form type, Komax
Type, Lightnin type, Ross ISG type, Prematechnik PMR type static mixer, etc., but chlorine gas or olefin gas is dispersed as fine bubbles in an aqueous solution to accelerate gas dissolution in downstream piping. Therefore, those having good gas-liquid dispersion performance are preferable. Examples of such a mixer include an ejector, a plate-shaped or cup-shaped stationary plate-type mixer, and a Kenics-type, Sulzer-type, and other static mixers.

Further, as the static mixer, it is preferable to select one in which the flow state of the fluid after mixing is likely to be a bubble flow, and an ejector, a plate-shaped or cup-shaped impingement plate-type static mixer, a Sulzer A static mixer such as a mold is particularly preferred.

In order to reduce the supply pressure of chlorine and olefin, it is preferable that the pressure difference between the inlet and the outlet is small.

In the present invention, the method of preparing the aqueous solution of chlorine dissolved in the flow channel of the tubular reactor is not particularly limited as long as it is adjusted to a concentration required for the reaction with the olefin. For example, before being supplied to the tubular reactor, a dissolution tank may be provided, and chlorine may be blown into water in the vessel to prepare the solution. However, industrially, water is supplied to the tubular reactor. In addition, a method in which chlorine is supplied and prepared by mixing with a static mixer is preferable.

The chlorine concentration of the prepared aqueous solution of dissolved chlorine is reduced by the reaction with the supplied olefin while flowing through the inside of the tubular reactor. During the process, the concentration of chlorine in the aqueous solution of chlorine can be adjusted. Also in this case, it is preferable to provide a static mixer and mix after supplying the chlorine gas because chlorine can be efficiently dissolved in the aqueous solution of chlorine.

In the present invention, the chlorine gas may be gaseous purified chlorine once liquefied and vaporized, but it is preferable to use unpurified gaseous chlorine having a purity of about 99% containing oxygen and moisture generated by electrolysis. Economical and preferred.

It is sufficient that the supply pressure of the chlorine gas overcomes the pressure of the liquid flowing in the flow path and that the pressure is sufficient to supply the chlorine gas. Usually, it is in the range of 1K Pascal gauge to 700K Pascal gauge.

The supply amount of chlorine gas is not particularly limited as long as it is lower than the solubility of chlorine determined by pressure and temperature, but if it is too large, by-products tend to increase. This increases the time and tends to induce side reactions as well as upsizing of the reactor.

Therefore, usually, the chlorine concentration after dissolution is 500
２０20000 ppmw, especially 4000-1500
It is preferable to supply chlorine gas so as to be in the range of 0 ppmw.

The supply of chlorine gas is performed upstream of the static mixer except when the static mixer is an ejector. However, when the static mixer is an ejector, when water passes through the ejector, the chlorine gas is supplied. In order to supply chlorine gas at the generated negative pressure, it is necessary to provide a supply port inside the ejector. This is the same when the olefin gas described later is supplied to the gas supply port of the static mixer.

In the present invention, the most important requirement is that the operation of supplying the olefin gas to the aqueous solution of chlorine and mixing it with the static mixer at least once is performed in the flow path of the aqueous solution of hydrochloric acid. To remove the chlorhydrin aqueous solution without circulation.

That is, according to the conventional method for producing chlorohydrin, in order to obtain a chlorhydrin aqueous solution having a certain concentration, an olefin is supplied while circulating an aqueous solution of chlorine between a reactor and a circulation tank. A method has been adopted in which a reaction solution having a target concentration is taken out from a circulation tank.

That is, in order to reduce the chlorine concentration after dissolution for the purpose of preventing the formation of by-products generated by the addition of chlorine to the double bond, the reaction solution is circulated and used before the reaction with the olefin. A method was used in which the amount of chlorine dissolved was kept low. For example, in the case of the latter technology having a relatively high chlorine concentration, only 4000 ppm of chlorine is dissolved at the maximum.

Therefore, an aqueous solution of chlorhydrin containing chlorhydrin having a concentration close to the removal concentration always exists in the reaction system, increasing the probability that a side reaction between chlorohydrin and chlorine will occur, and further increasing the possibility of producing chlorohydrin. The selectivity of chlorohydrin was reduced by increasing the probability of formation of ethers by the reaction between the body and the formed chlorohydrin.

On the other hand, the method of the present invention continuously raises the concentration of chlorhydrin, which is a product in the flow path, while preventing the liquid after mixing the olefin gas from mixing with the previous liquid. In short, by removing the obtained reaction solution without circulation, it is possible to greatly reduce the probability that a side reaction between chlorhydrin and chlorine will occur, and furthermore, the intermediate between chlorohydrin and chlorohydrin produced when chlorohydrin is produced Chlorhydrin can be obtained at a high selectivity because the probability of occurrence of the reaction can be reduced.

Incidentally, according to the method of the present invention, 1% by weight
When a chlorhydrin aqueous solution having a concentration of 1% is obtained, it is possible to increase the selectivity by 1% or more as compared with the conventional method by circulation, which is a very advantageous method in the industrial production of chlorhydrin as a mass production product. It can be said that.

In the method of the present invention, in particular, the higher the concentration of the target chlorhydrin, the more remarkable the effect of the present invention is, compared to the conventional technique using a circulation system. Usually, the target chlorhydrin concentration is 0.4 to 7% by weight, in particular,
The effect is remarkable when an aqueous chlorhydrin solution in the range of 0.6 to 5% by weight is obtained.

As described above, when the target chlorhydrin concentration is high, it is preferable to supply the olefin gas a plurality of times and, if necessary, supply the chlorine gas in the flow path of the aqueous solution of chlorine solution. Then, a chlorohydrin aqueous solution having a desired concentration is taken out from the rear end of the tubular reactor without circulation, whereby chlorohydrin can be produced with high selectivity.

In the present invention, the olefin used is
Although not particularly limited, C _Two~ C_FourOlefin
Is commonly used. Among them, especially ethylene and propylene
Ren and allyl chloride are preferred.

The purity may be easily available industrially, and generally a purity of about 95% to 96% is used.

It is sufficient that the supply pressure of the olefin gas is sufficient to overcome the pressure of the fluid flowing through the tubular reactor and supply the olefin gas. Usually, it is in the range of 1K Pascal gauge to 700K Pascal gauge.

When the supply amount of the olefin gas is too large, unreacted substances tend to increase, and when the supply amount is too small, by-products tend to increase. Therefore, a range of 0.9 to 1.2, particularly a range of 1 to 1.1 is recommended.

When chlorine gas is supplied through the flow path, the supply position of the olefin gas is preferably a position where the supplied chlorine gas is sufficiently dissolved. Such a position may be determined in advance by an experiment, but it is usually preferable to secure a residence time of 4 seconds or more after mixing chlorine to ensure complete dissolution of chlorine.

When chlorine gas is supplied after the olefin gas is mixed, or when chlorhydrin aqueous solution is taken out, a residence time of 10 seconds or more is secured to complete the reaction rate between the dissolved chlorine and the olefin. Is preferred.

Thus, the olefin gas is mixed with the aqueous solution of chlorine in the static mixer, and after a residence time necessary for the reaction, is taken out from the rear end of the tubular reactor with high selectivity as an aqueous chlorohydrin solution.

The supply of the olefin gas and the chlorine gas is preferably performed without diluting the gas. However, if necessary, the olefin gas and the chlorine gas may be supplied by diluting with an inert gas such as propane, ethane, nitrogen or argon. It is also possible.

In the present invention, the most preferred embodiment is to supply water to a tubular reactor, supply chlorine gas in the flow path to prepare a chlorine-dissolved aqueous solution, and then supply and mix olefin gas to produce chlorohydrin. And the operation of supplying and mixing chlorine gas and capturing the chlorine reduced by the reaction are repeatedly performed, thereby sequentially increasing the concentration of chlorohydrin in the flow path, and the rear end of the tubular reactor. In this embodiment, chlorhydrin having a high concentration is taken out from the opening.

In the present invention, the tubular reactor may be constituted by providing a plurality of sets of the supply and mixing of the chlorine gas and the olefin gas described above in one tubular reactor. A plurality of tubular reactors having a single supply and mixing point may be connected in series.

When a plurality of tubular reactors are connected in series, a pump may be provided at the connection to restore the supply pressure of the liquid, and there is no problem.

The direction in which the tubular reactor is installed can be horizontal, inclined, or vertical. However, when installed horizontally or inclined, a laminar flow or a wavy flow is likely to occur, resulting in poor gas absorption efficiency. Since the length of the gas absorption pipe installed downstream of the static mixer tends to be long, the flow state of the fluid consisting of bubbles of chlorine or olefin finely dispersed in water in the static mixer is a bubble flow, plug Flow, or slug flow, it is particularly preferable to be a bubble flow, it is preferable to install so as to be a downward flow in the vertical direction as much as possible, the range of the bubble flow is wide, the overall length of the device is short It is particularly preferable because it can be easily scaled up.

In the present invention, if the reaction temperature is too high, the selectivity of the target product, chlorohydrin, tends to be low.
It is preferable to adjust the temperature to 0 ° C. or lower. The method for such adjustment is not particularly limited, but a method for adjusting the temperature of water or an aqueous solution of chlorine to be supplied to the tubular reactor is preferable. That is, the temperature of the water or the aqueous solution of chlorine dissolved supplied to the tubular reactor is preferably 70 ° C. or less, and particularly preferably in the range of 0 to 60 ° C. in consideration of the heat of reaction for chlorhydrin formation.

In the present invention, the supply pressure of the water or the aqueous solution of chlorine to be supplied to the tubular reactor is not particularly limited. However, in order to guarantee the passage of the liquid, the recovery of the pressure due to the difference in elevation will be described later. It is sufficient that the total pressure loss of the static mixer is equal to or higher than the atmospheric pressure.

When the stationary mixer is an ejector, the supply water pressure is used as the driving force of the ejector, and it is preferable that the pressure is equal to or higher than the pressure necessary for driving the ejector in order to guarantee complete gas absorption.

In the present invention, the flow rate of the water or the aqueous solution of chlorine to be supplied to the tubular reactor is sufficient to bring out the gas mixing performance of the static mixer, and the flow state of the fluid after the gas mixing is a bubble flow. It is preferable to adjust either the plug flow or the slag flow, particularly the bubble flow.

Although the above preferred flow rate cannot be limited unconditionally, usually, the flow rate of the liquid introduced into the static mixer is 0.3.
４4 m / sec, preferably 0.7 to 3 m / sec.

The flow rate can be generally adjusted by adjusting the flow rate of the water or the aqueous solution of chlorine and the diameter of the pipe supplied to the tubular reactor (Chemical Engineering Handbook, 5th edition).
272-276, edited by the Society of Chemical Engineers).

In the present invention, an embodiment in which the alkali is added to the aqueous solution of chlorine dissolved in the flow channel of the tubular reactor within a range where the pH does not become 7 or more is a preferable embodiment in order to achieve a higher selectivity of the obtained chlorohydrin. It is.

The reason why the selectivity for chlorhydrin is further improved by the addition of the above alkali is estimated as follows.

That is, when chlorine is dissolved in water, a reversible reaction occurs in which chlorine reacts with water to generate hypochlorous acid and hydrochloric acid. In the method of the present invention, the generated hydrochloric acid is selected from the magnitude of its dissociation multiplier (hypochlorous acid 4 × 10 ⁻⁸ , hydrochloric acid 1 × 10 ⁻¹ ) because alkali is supplied to chlorine dissolved in water. Neutralized to form salts. As a result, in the reversible reaction, a reaction for generating hypochlorous acid is promoted, and an aqueous solution having a very low chlorine concentration and a high hypochlorous acid concentration can be obtained. In the present invention, since the olefin is supplied to such a solution stream, it is possible to suppress the generation of by-products caused by the addition of chlorine to the double bond, and the selectivity of chlorohydrin, which is the target product, is reduced. It is likely to be even higher.

The kind of alkali supplied for adjusting the pH is not particularly limited, but alkali metal hydroxides such as lithium hydroxide, sodium hydroxide and potassium hydroxide, magnesium hydroxide, calcium hydroxide, and hydroxides. Alkaline earth metal hydroxides such as barium, alkali metal carbonates such as sodium carbonate, sodium bicarbonate, and potassium carbonate, and alkaline earth metal carbonates such as magnesium carbonate and calcium carbonate are preferable, and are easily available. Thus, calcium hydroxide is particularly preferred.

The amount of the alkali added is preferably within the range where the pH of the aqueous solution of chlorine does not exceed 7, as described above. In particular, the supply amount of the alkali is controlled so that the pH is in the range of 3 to 6. This is preferable because a solution having a low concentration of chlorine and a high concentration of hypochlorous acid can be obtained.

That is, when the pH becomes 7 or more, hypochlorous acid is neutralized, or the supplied alkali remains, and comes into contact with the olefin to cause a side reaction to produce an olefin oxide, an olefin diol, an ether compound or the like. It is not preferable because it may occur.

The method of supplying the above-mentioned alkali is not particularly limited, but usually it is preferable to continuously supply it as an aqueous solution or slurry of 1 to 40% by weight. At this time, it is preferable to perform pH control using a pH control device including a pH detector for the fluid in the tubular reactor and a valve for adjusting the flow rate of the alkali based on the signal.

The addition of the alkali is preferably performed using the same static mixer as used for the above-mentioned gas.

The thus-obtained solution having a low chlorine concentration and a high hypochlorous acid concentration is mixed with an olefin gas in a static mixer for mixing an olefin gas, and chlorhydrin can be efficiently produced.

In addition, chlorine is dissolved in water in a very short time by the addition of an alkali. Therefore, it is possible to shorten a suitable staying time after mixing the chlorine gas, and usually, the staying time is 2 seconds. This is enough.

The method of the present invention is particularly advantageous when producing a chlorhydrin aqueous solution having a relatively higher concentration than a chlorine-dissolved aqueous solution having a chlorohydrin concentration of zero or extremely low, but the chlorhydrin aqueous solution obtained by the method of the present invention is advantageous. In order to further increase the concentration, it is also possible to supply the chlorohydrin aqueous solution obtained by the method of the present invention to a chlorohydrin tower conventionally used industrially without any limitation.

The aqueous chlorohydrin solution obtained by the method of the present invention can be used as it is as a raw material for producing propylene oxide.

The apparatus for carrying out the method of the present invention is not particularly limited as long as it satisfies the above-mentioned manufacturing requirements, but preferred examples include the following apparatuses.

That is, according to the present invention, the tubular reactor has a water supply port at the front end thereof, and the tubular reactor has a stationary gas supply port for supplying the gas to be mixed to the flow path. At least one unit provided with at least two mold mixers, wherein chlorine gas is supplied to a gas supply port of a stationary mixer located upstream of the unit and gas is supplied to a stationary mixer located downstream of the unit. An apparatus for producing chlorohydrin, characterized in that an olefin gas is supplied to each of the ports and an outlet for collecting an aqueous chlorohydrin solution is provided at a rear end of the tubular reactor.

Hereinafter, a typical embodiment of the above apparatus will be described with reference to FIG.
2 will be described.

The apparatus shown in FIG. 1 shows an embodiment having three units each having at least two static mixers.
That is, the embodiment of the apparatus shown in FIG. 1 has a supply port 2 for water C at the front end of the tubular reactor 1, and the static mixers 13, 23, 33 located upstream of the units 1 to 3. Gas supply port 1
Chlorine gas A is supplied to the gas supply ports 15, 25, 3 of the stationary mixers 16, 26, 36 located on the downstream side.
5 to supply olefin gas B respectively,
At the rear end of the tubular reactor, there is an outlet 3 for collecting an aqueous chlorhydrin solution.

In FIG. 1, water C is supplied from a supply port 2 into the apparatus, mixed with chlorine gas supplied from a gas supply port 12 in a static mixer 13, and chlorine is dispersed in water as fine bubbles. You.

Next, the water mixed with the chlorine gas A is dissolved in the chlorine gas in the flow path 14 of the tubular reactor, and the water is completely dissolved before reaching the olefin supply port 15. Prepared.

Thereafter, the olefin gas B is supplied from the olefin supply port 15 to the channel, and is supplied to the aqueous solution of chlorine dissolved passing through the channel.

The supplied olefin gas is mixed with the aqueous solution of chlorine in the static mixer 16, and the olefin gas is dispersed as fine bubbles in the aqueous solution of chlorine.

In the flow channel 17 following the stationary reactor, the reaction of olefin, chlorine and water proceeds, and the production of chlorohydrin and hydrogen chloride proceeds.

The aqueous solution of chlorine dissolved containing chlorhydrin thus produced can be taken out as it is, but in the embodiment shown in FIG.
The unit has a unit, whereby a high-concentration aqueous solution of chlorohydrin can be taken out from the outlet 3 of the tubular reactor 1.

On the other hand, the apparatus shown in FIG. 2 shows a mode for adjusting the pH of the aqueous solution of chlorine by adding an alkali in the apparatus shown in FIG.

That is, in the apparatus shown in FIG. 2, the alkaline aqueous solution E is supplied to the flow path immediately after the flow path 14 for preparing the aqueous solution of chlorine.
An alkali supply port 42 having a control valve 41 for adding while performing the control is provided, and on the downstream side thereof, a static mixer 43, a pH detector 45, and a pH detector 45
The arithmetic unit 44 is provided for converting the above signal into a signal for controlling the control valve 41.

The aqueous solution of chlorhydrin containing chlorhydrin thus produced can be taken out as it is. However, in the embodiment shown in FIG. 2, two units of FIG. 1 are further provided, thereby increasing the chlorhydrin content. A high concentration aqueous chlorhydrin solution can be taken out from the outlet 3 of the tubular reactor 1 while ensuring the selectivity.

In each of the above apparatuses, the number of the static mixers provided after the gas or the liquid is supplied to the flow path is not particularly limited, and may be one or two or more. You may.

Further, although not shown in the figure, if the dissolved chlorine in the aqueous solution of chlorine dissolves sufficiently after the olefin is supplied and reacted, the olefin supply port is continuously connected to the olefin supply port without providing a chlorine supply port. An embodiment in which a mold mixer is provided in the flow path is also possible.

The material for forming the apparatus of the present invention is not particularly limited as long as there is no problem such as corrosion except for the nozzle portion of the chlorine supply port. For example, a lining made of a polymer material such as PTFE and a corrosion-resistant metal material such as Ti can be exemplified. Since the nozzle portion of the chlorine supply port reacts with chlorine when Ti is used, it is preferable to use a polymer material such as PTFE.

[0080]

As will be understood from the above description, according to the present invention, a high chlorohydrin selectivity is ensured,
Chlorhydrin can be industrially advantageously produced.

In particular, when a target product having a relatively high chlorhydrin concentration is obtained, the effect of exhibiting a higher chlorohydrin selectivity than in the prior art is remarkable.

Therefore, the industrial value of the present invention is extremely high.

[0083]

The present invention will be described in more detail with reference to the following Examples, which by no means limit the scope of the present invention.

Example 1 An apparatus having one unit provided with two stationary mixers, ie, having a chlorine supply port and a propylene supply port,
Equipped with a Kenics-type static mixer for chlorine and propylene mixing, 9.6 mm inside diameter with front and rear ends
A pipe reactor was used in which the distance from the chlorine mixer to the propylene supply port was 6 m, and the distance from the propylene mixer to the rear end of the pipe was 10 m.

Water at 21 ° C. is 0.12 m from the front end of the pipe.
Was supplied at ³ / Hr rate of chlorine was fed at a rate of 0.12 m ³ / Hr, was chlorohydrin reduction reaction by supplying propylene at a rate of 0.18 m ³ / Hr.

A chlorohydrin aqueous solution was taken out from the rear end of the pipe and analyzed. As a result, the propylene chlorohydrin concentration was 0.41%, the chlorine conversion was 100%, and the propylene chlorohydrin selectivity was 97.9%. Was.

When the chlorine concentration was measured by sampling at a position immediately before the propylene supply port, it was 3145 ppm.
w, and the supplied chlorine was completely dissolved. (Table 1
3 and FIG. 3).

Examples 2 to 4 Chlorhydrination was carried out using the apparatus shown in Table 1 and the reaction conditions shown in Table 2. Table 3 and FIG.
Shown in

Example 5 An apparatus having three units each provided with two static mixers shown in Table 1, that is, an apparatus shown in FIG. 1 was used, and a speed of 1.00 m ³ / Hr was supplied from each chlorine supply port. Chlorine was supplied at a rate and propylene was supplied from each propylene supply port at a rate of 1.10 m ³ / Hr, and a chlorohydrination reaction was performed under the reaction conditions shown in Table 2. The results are shown in Table 3 and FIG.

Examples 6 to 8 An apparatus having one unit provided with two static mixers shown in Table 1 and an apparatus having a device for adjusting the pH of an aqueous solution of chlorine dissolved by adding an alkali were added. Using 17% lime milk as an alkali, the pH was controlled by supplying from an alkali supply port, and a chlorhydrination reaction was performed under the reaction conditions shown in Table 2. The results are shown in Table 3 and FIG.

Examples 9 to 10 One unit obtained by adding a device for adjusting the pH of an aqueous solution of chlorine solution by adding an alkali to a device having one unit provided with two static mixers shown in Table 1 is added. To
The apparatus which does not have a device for adjusting the pH, in which two units are arranged in series, that is, the apparatus shown in FIG. 2, is supplied with chlorine at a rate of 1.00 m ³ / Hr from each chlorine supply port,
Using 17% lime milk as an alkali, pH is controlled by supplying from an alkali supply port, and propylene is supplied from each propylene supply port at a rate of 1.10 m ³ / Hr.
The chlorhydrination reaction was carried out under the reaction conditions shown in (1). The results are shown in Table 3 and FIG.

Comparative Examples 1 and 2 A gas-liquid separator was connected to the rear end of the apparatus, and the liquid phase was circulated to the front end of the apparatus using a pump, and a part of the chlorhydrin aqueous solution was extracted. The rest was carried out under the conditions shown in Tables 1 and 2, except that the chlorhydrin aqueous solution was extracted by the same amount as the flow rate of the feed water, using an apparatus adapted to merge with the feed water. The results are shown in Table 3 and FIG.

[0093]

[Table 1]

[0094]

[Table 2]

[0095]

[Table 3]

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an embodiment of a typical apparatus used in the method of the present invention.

FIG. 2 is a conceptual diagram showing an embodiment of another typical apparatus used in the method of the present invention.

FIG. 3 is a graph showing the relationship between chlorhydrin concentration and chlorohydrin selectivity in Examples and Comparative Examples.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tube-type reactor 2 Water supply port 3 Outlet 12,22,32 Chlorine supply port 13,23,33 Stationary mixer for chlorine mixing 14,24,34 Channel for chlorine dissolution 15,25,35 Olefin supply port 16, 26, 36 Static mixer for olefin mixing 17, 27, 37 Flow path for reaction 41 Control valve 42 Alkali supply port 43 Static mixer for alkaline mixing 44 Operation unit 45 pH detector

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tomoaki Fujii 1-1 Mikage-cho, Tokuyama-shi, Yamaguchi Pref. Toku Yamauchi Co., Ltd. (72) Inventor Kojiro Miyazaki 1-1 Mikage-cho, Tokuyama-shi, Yamaguchi Pref. Terms (reference) 4G035 AA01 AB27 AC01 AE13 4H006 AA02 AC30 AC41 BC16 BD21 BD81 BD84 BE53 BE60 FE11 FE71 FE75

Claims (7)

[Claims] Claims 1. An operation of flowing an aqueous solution of chlorine in a channel of a tubular reactor, and supplying an olefin gas to the aqueous solution of chlorine in the channel and mixing it with a static mixer at least once, A method for producing chlorhydrin, comprising removing the obtained chlorhydrin aqueous solution without circulation. 2. The method for producing chlorhydrin according to claim 1, wherein the concentration of chlorine in the aqueous solution of chlorine is adjusted by supplying chlorine gas to the flow path and mixing with a static mixer. 3. The method for producing chlorhydrin according to claim 1, wherein an alkali is added within a range where the pH of the aqueous solution of chlorine in the flow channel does not become 7 or more. 4. The liquid in the flow path after mixing the gas forms one of a bubble flow, a plug flow and a slag flow.
The method for producing chlorhydrin according to any one of the above. 5. A water supply port at a front end of the tubular reactor,
The tubular reactor has at least one unit provided with at least two stationary mixers each having a gas supply port for supplying a gas to be mixed to a flow path, and a stationary unit located upstream of the unit. Chlorine gas is supplied to the gas supply port of the mold mixer, and olefin gas is supplied to the gas supply port of the stationary mixer located on the downstream side, and an aqueous chlorhydrin solution is recovered at the rear end of the tubular reactor. An apparatus for producing chlorhydrin, comprising an outlet. 6. The chlorohydrin production apparatus according to claim 5, wherein an alkali supply port is provided before the mixed gas supply port for supplying the olefin gas. 7. The apparatus for producing chlorhydrin according to claim 5, wherein the apparatus has two or more units.