DE1943331B - Process and device for the production of glycerol dichlorohydrin - Google Patents

Description

The present invention relates to a process for the preparation of glycerol dichlorohydrin by reacting allyl chloride with aqueous chlorine solution and an apparatus for carrying out this process.

In the previous production process of glycerol dichlorohydrin, allyl chloride was with a aqueous chlorine solution reacts. This reaction can be represented by the following formulas:

Cl ₂ + H ₂ O -> ClOH + HCl

CHo = CHCH., C1 4- HOCl

f CH ₂ OHCHC1CH, C1 {or

[CH ₂ CICHOHCH ₂ Ci

However, the above reaction is accompanied by undesirable side reactions, which affects the yield of the Glyceri'idichlorhyd- ^ s impaired. These side reactions can be represented by the following formulas:

CH, = CHCH..C1 -; - Cl ₂ -> CH ₂ C1CHC1CH, CI

(3) CH ₂ UHCHCICHoCl • - CH ₂ = CHCH ₂ Cl + Cl ₂

CH ₂ CICHCICH ₂ OCH ₂ CHCICh ₂ CI ~ | - HCl

In order to avoid these side reactions and the resulting by-products, various have hitherto been used Proposed procedure.

In one of these processes, liquid allyl chloride is introduced into a reactor, which is an aqueous one Contains chlorine solution. The mixture mentioned is reacted with stirring. However, it can also be used with this Process the side reaction (3) between chlorine and allyl chloride occur. In the process mentioned the yield of the by-products cannot be reduced by any device below 7 to 8% - based on the weight of the converted allyl chloride,

ίο when the concentration of glycerol dichlorohydrin in of the reaction mixture is approximately 0.2 to 0.4 mol / l.

In another known method according to Japanese Patent 405,205, the allyl chloride is converted into the gas phase and then mixed with an inert gas such as nitrogen. The composition of this gas mixture is adjusted in advance so that the freezing point of the allyl chloride in the gas mixture is below the reaction temperature. This gas mixture is introduced into a reactor filled with an aqueous chlorine solution, in which the two substances are reacted. The reaction therefore takes place in the absence of liquid allyl chloride. With the system mentioned it is possible to bring the side reactions in the liquid phase under control, but the following disadvantages have to be accepted. When the allyl chloride-containing G.ise is introduced into a reactor filled with an aqueous chlorine solution, part of the originally dissolved chlorine is stripped off. This leads to the fact that the allyl chloride reacts with the chlorine in the gas phase. In such a gas phase, however, there is also the possibility that a side reaction (3) can occur. It was found that complicated measures have to be taken to avoid the disadvantages mentioned. As such, a special method for bringing the allyl chloride-containing gas into contact with the chlorine or carrying out the bringing together of the substances in several separate steps can be considered.

It is therefore the object of the present invention to provide a method in which allyl chloride with good yield and with a remarkable suppression the side reactions is formed. The formation of the by-products is said to be in a simple manner Proceedings are prevented. A further object of the present invention is to provide a device indicate with which the above procedure can be carried out effectively.

This object is achieved in that the allyl chloride is also used as an aqueous solution.

According to a preferred embodiment

the aqueous chlorine solution fed to the reaction zone in two to five stages.

The aqueous phase is preferably circulated after the organic phase has been separated off.

100 to 110 parts by weight of allyl chloride can be reacted with 100 parts by weight of chlorine each time. An ejector can be used to dissolve the chlorine in an aqueous liquid, the ejector advantageously using the aqueous reaction liquid as the operating liquid in order to dissolve the chlorine therein. It is also advantageous to choose the pressure of the ejector between -700 and 1000 cm H _{2 O.}

The device for carrying out the method according to the invention contains a storage vessel for the Receiving the aqueous reaction solution, a device door the water supply to an ejector

3 Γ ⁴

Chlorine in part of the from the storage container

to dissolve withdrawn reaction liquid, an allyl chloride and the chlorine each directly in fresh

Dissolving tank for the dissolution of the allyl chloride in water before being put into the reaction

another part of the discharge zone from the storage container. However, it is common

withdrawn reaction liquid, a reactor to prefer the 5 to circulate the reaction liquid

Let aqueous chlorine solution with the aqueous allyl chloride and the allyl chloride in a part of this

solution to react, as well as devices to dissolve a liquid, while the chlorine in a

Subtract part of the reaction mixture. other part of the same liquid is dissolved, so

The reactor is preferably tubular so that both substances react in the reaction zone and, in an advantageous embodiment, can be formed. It is possible here to provide the reaction system with devices so that the from the ejector is designed in such a way that a part of the reaction liquid gate coming aqueous chlorine solution is continuously withdrawn as a product in several stages and stages can be entered. As a favorable starting point at the same time a corresponding part of water continuous measurements for the tubular reactor recommend lent wildly to the system.
a diameter of 2.54 cm to 50.8 cm and a 15 to dissolve allyl chloride and chlorine in a total length of 4 to 20 m. The said aqueous reaction liquid can expediently be produced in the tubular reactor ^ from titanium. In the event that both substances are present in a gi-shaped form, it is advantageous to use the pressure of the ejector between 700 and 1000 cm H ₂ O devices. allow switching between gas and liquid.

The drawing serves to further explain FIG. 20, such as, for example, a packed column, an ejector

Invention. Show it or something like that (usually chlorine is in gaseous form

F i g. 1, 2 and 3 scheme drawings from Appara- available and allyl chloride in liquid form). When

Doors for carrying out the combination according to the invention, both substances are in a liquid state, they can

be dissolved in tanks with stirring, for example

F i g. 4 shows a comparison between the two in a diagram. Since the solubility of allyl chloride see in water the result as one is small at a trial than that of the chlorine, it is of course wündurchführung according to Example 1 is (A), with the visit, a larger amount of water (for AufErgebnis B ) d «'s usual procedure. solution of the allyl chloride than for the dissolution

Extensive investigations were carried out to resolve the chlorine. At the introduction of the allyl chloride leads to find possibilities that a conversion of the chlorine into the reaction scene does not have to be saved of allyl chloride in the glycerol dichlorohydrin cial restrictive condition are met, allow to carry out with high yield and thereby it is favorable, however, to prevent the formation of secondary die Formation of by-products as small as possible to suppress the solutions of the substances keep. In these investigations it was found to admit that there was an excess compared to the culor Allyl chloride, allyl chloride, soluble in water in the reaction zone is. (It dissolves 0.36 percent by weight in the is. So it is particularly favorable to per in the time water at a temperature of 20 "C) Furthermore, 100 parts by weight of chlorine entered approximately it was found that. if one adds 100 to 110 parts by weight of allyl chloride while utilizing, this circumstance allyl chloride in the reaction zone Larger proportions of allyl chloride than mentioned above Entered as an aqueous solution, the formation of minor 40 lead to no further noticeable reduction products are kept to a minimum and the yield in the formation of by-products. However, it can of glycerol dichlorohydrin are significantly increased by it to an undesirable increase in the can. As expected, the proportion of unreacted allyl chloride that leads to such an increase in gen production the costs for the preparation and the implementation of the glycerol dichlorohydrin obtained as a product of the system. This disadvantage, will 45 solution is included.

however .on the advantages mentioned above reduced. It is also found that the yields of

It was found that the disadvantages are completely compensated for. By-products are further reduced considerably

let and that with the present invention even can and the speed of the desired

a remarkable reduction in the production reaction is intensified when the aqueous solution of the

cost of glycerol dichlorohydrin becomes possible. 50 chlorine in two or more stages of the reaction

In the present invention, therefore, delivery is made to the heart zone. If you put the chlorine solution in the

setting of Gly / ierindichlorhydrir !, allyl chloride and entering the reaction zone in two stages, it is possible to

Chlorine brought together after both substances in the proportion ier by-products to half of the

an aqueous liquid have been dissolved in a one-stage system of unavoidable proportions

(For example, press down in water or the reaction liquid. The proportion of by-products is

speed). This makes it possible to reduce the chlorine even further in comparison to the up to ^{now, if η Λ} αη the chlorine in five

previous process Gly2.erindichlorhydrin adds in high or more stages. A use of sol-

Produce yield and at the same time the formation of ι multistage systems can, however, to a certain extent

Remarkably suppress by-products. Disadvantages in operation and less reaction

This result can be attributed primarily to speeds. Therefore it turns out to be :

lead that, in contrast to the previous decay, the cheapest, systems with two to five levels zi

ren, in which the allyl chloride with the chlorine either use. With such a system, you don't have to

in an organic phase, which in a gas phase always necessarily represents the proportion of the chlorine solution;

is brought to be the same in each stage in the present invention. So you can system

train both reactants only in an aqueous solution 65 in such a way that the supplied in one stage *

react. The progress that can be achieved in this way is the proportion of chlorine solution greater than that in Flußrich

from the examples treated below, the following stage can be seen or vice versa. It is also

^i: ' ^u possible to use a three-tier system with the

the proportions of the chlorine solution progressively from the first reaction liquid continuously from the reactor Stage in the direction of flow via the middle stage and drawn off into a storage vessel 6. From this bottom of the supply Increase level. But it is also possible, vessel 6 becomes part of the reaction liquid as prosie increase in exactly the opposite direction. deducted duct, as indicated by arrow 10 in A b b. I. Furthermore, the largest proportion of the chlorine solution 5 can also be shown. At the same time, by-products are like or the smallest proportion in the middle stage to- trichloropropane, bis-dichloropropyl ether, etc., of the are given. System deducted, thereby avoiding this

The reactor, in which the aqueous solution of the allyl impurities in the circulating liquid

chlorides reacts with the aqueous solution of chlorine to be enriched.

is, in the present invention, a tubular io With the allyl chloride, additional water 9 in be a shaped reactor. However, it is of course also possible to enter the allyl chloride dissolution tank 4, with A normal tank or tower reactor can use this amount of the withdrawn glycerine solution. Using a tubular reactor yields dichlorohydrins equivalent.

however, there are some advantages. It turns out to be for example F i g. 2 shows a typical apparatus in which a

wise for easier control of the reaction and 15 tubular reactor is used. With the

for a reduction in the dimensions of the reaction reference numeral 11 denotes a storage vessel which

plant as beneficial. contains the reaction liquid. Capacity

In the previous method, in which the liquid and the size of this storage vessel are correspondingly allyl chloride is used as such, the capacity of the rest of the apparatus cannot, however, be used in a fixed tubular reactor. 20 laid. Part of the withdrawn from the storage vessel 11 is due to the fact that the tubular reactor does not bring the necessary movement of the reaction mixture under pressure by a pump 14 before it is introduced into an ejector 12, so that on In this way an increase in the pressure that sucks up chlorine in the ejector varies. Side reactions occur, generally the reaction usually between -700 and 1000 cm H ₂ O. according to formula (3) and the following reaction according to 25 in the present example pre-forms used! (4). In the present case, a tube direction clearly differs from a device, shaped reactor, successfully used in order to create a more economical system for the solution of the chlorine in the production of glycerol dichlorohydrin . In addition, the suction pressure generated by the ejector was used using an ejector to dissolve the chlorine. 30 finds. In the previous arrangements, the word "ejector" means that all devices are a special compression system to mean the chlorine, which can dissolve a liquid at high speed and can eject the higher pressure of the reaction and absorb the chlorine, to overcome liquid. In the case of the present appa, with the resulting hydrodynamic pressure equipment, it is therefore not necessary to use any device. To be provided as the operating fluid for a device for higher pressures, since the dissolution against the ejector, the above-mentioned chlorine can preferably be used in the reaction fluid, which flows smoothly. effective during the execution of the process

The device according to the invention for a conti- rens takes place through the suction pressure of the ejector,

nual production of glycerol dichlorohydrin should, for example, if the suction pressure of the

in the following with reference to FIG. 1 to 4 in the individual 40 lying apparatus used ejectors between

be discussed. _ -100 and -400 cm H ₂ O are set for the

F i g. Fig. 1 shows a typical apparatus with an absorption of chlorine in the reaction liquid only

Reaction vessel with stirrer. It takes one reactor 1 0.5 seconds to achieve a chlorine concentration

The reaction liquid to be withdrawn will be of 2 to 5 g / liter. The reaction liquid,

Pump 2 circulated in such a way that the chlorine and the 45 in which the chlorine is dissolved in this way still wild

Allyl chloride can be dissolved on the way. It before being introduced into the tubular reactor 16

is therefore a part of the reaction liquid in a is, by the pump 19 under pressure with the reac-

Chlorine dissolving tower 3 introduced. Mixed as a chlorine dissolving tower 3 tion liquid, in which the allyl chloride 17

a packed column is used in which the liquid was dissolved in the same way. Then will

the chlorine gas introduced at 7 dissolves. 50 put this mixture into the tubular reactor.

Another part of the reaction liquid is passed into. Length and shape of the tubular reactor

an allyl chloride dissolving tank 4 is introduced, in which this depends on the concentrations of the introduced

at 8 entered allyl chloride in the liquid up- allyl chloride and chloride from as well as from the reaction

is resolved. The resulting solution is first placed in a temperature. They are chosen so that the necessary

Separation tank 5 initiated. In this way, the 55-day reaction within the tube is completed

it is not in the reactor, but is in the dissolving is. Preferably, a reactor with a

tank 4 returned. The allyl chloride solution as well as internal diameters from 2.54 to 50.8 cm and one

the chlorine solution is continuously used in the reactor 1 length from 10 to 20 m,

entered. In this way they are used in their aqueous material for the manufacture of the tubular

Solutions the allyl chloride and the chlorine continuous 60 reactor can be corrosion and heat resistant

borrowed and used in a certain ratio to each other in substances such as titanium or the like

initiated the reactor 1. The allyl chloride and the det are To the Raur, who has been prepared for the system

Chlorine in the aqueous solution react with this, and the tubular reactor can be used to reduce it

each other only in the aqueous phase, so that one net in a zigzag or other arrangement

good yield of glycerol dichlorohydrin is obtained. 65 can be attached. The concentration of the Giyzerir

In order to ensure better mixing of the two reaction dichlorohydrins in the <ius of the tubular reactor

To obtain partner, it is advantageous if the reaction mixture flowing out well with the inlet is between

to stir differently. Then some of the 1 to 6 percent by weight. This mixture is used in de

7 8

Reservoir 11 returned, the. as mentioned. varies. The yield of glycerol dichlorohydrin

is adapted to the uptake of the reaction liquid. was determined in all cases. The respective relationship

The apparatus is operated in such a way that the concentration of the glycerine dichlorohydrin

the storage tank at all times a certain solution and the yield of glycerol dichlorohydrin

The amount of reaction liquid of the same concentration became as shown in FIG. 4, curve A can be seen, opposite one another

contains tration. For this purpose, as already with the other, is applied. For comparison, the manufacturer

game of F i g. 1 described the glycerine dichloride of glycerine dichlorohydrin under “Jen same

hydrin continuously from the reservoir 11 carried out conditions as in the Japanese

drawn as indicated by arrow 18. U.S. Patent 405,205. The results of this

An additional amount of water 13 is continuously used. Comparative experiments are shown in FIG. 4 d'irch the curve B

added to the system in such an amount that represented.

the amount of withdrawn liquid is compensated for. A relationship similar to that shown by curve B

will. from F i g. 4 was obtained when the

F i g. Fig. 3 shows an apparatus in which an aqueous glycerol dichlorohydrin is used according to another known one Chlorine solution in a tubular reactor of the 15 method was prepared in which the liquid AUyI-described Type in several successive chloride in a vertical, with an aqueous Levels is entered. Two parts of the column filled from the chlorine solution was introduced. The reaction liquid withdrawn from the storage vessel 20 is circulated by pumps 21 and 22. Example 3 Allyl chloride and chlorine are discussed in the corresponding 20

Divide the liquid dissolved. In this way, with an apparatus as shown in FIG. 2 shown

a first part of the reaction liquid is an allyl, glycerol dichlorohydrin was produced. The Pro

chloride dissolution tank 23 supplied, in which it was with the advice vessel (capacity 200 liters)

24 added allyl chloride dissolves. A second part of the water filled and it found a tubular reactor

Reaction liquid is fed to a chlorine dissolver (with a diameter of 2.54 cm and 20 m

tun.e 25 fed with an ejector, in which the 26 total length made of a titanium alloy) use. from

supplied chlorine gas in the corresponding part of the water in the storage vessel were 138m ³ / h for

Liquid is dissolved. the absorption of the chlorine and 138 m ³ h for the

The chlorine solution of the allyl chloride dissolved in the reaction liquid is pumped around. The absorption

is then fed to the reaction zone ABC. The 30 of the chlorine was fed through an ejector at a lot

Reaction liquid. in which the ejector 25 carried out that of 418 kg / h.

Chlorine has been dissolved! ", Is then converted into two or more cells leading to the formation of glycerol dichlorohydrin

split up several parts and the reaction zone in reaction ran exothermically and reached a constant

the corresponding part of the successive weight point at 40 ^l C.

Stages fed. (In Fig. 3, the chlorine solution is in 35 The reaction proceeded in the tubular reactor

two stages fed.) The from the reaction zone off smoothly. There could be no at the end of the tube

outflowing reaction liquid will be detected in a supply of free chlorine. In the tube itself

Vessel 20 supplied and at the point 27 continuously increased the concentration of glycerol dichlorohydrin

deducted. An additional water supply 28 takes place almost linearly over time. As soon as the concentration

in the allyl chloride dissolving tank 23. where the proportion had reached 40 tion 5 ° / _c , an additional water

of the added water of the amount of the withdrawn supply ^{put into operation at 30 m 3} / h, so that the

Glycerine dichlorohydrin solution. Reaction continued in an equilibrium state

The following examples serve to provide a further analysis of the withdrawn from the storage vessel

Disclosure of the present invention. Glycerine dichlorohydrins showed the following relationships

4Y setting:

Example 1 Glycerine dichlorohydrin 97.5 ° / ₀

In the in F i g. 1 apparatus shown, trichloropropane 1.8 ¹ V ₀

Glycerine dichlorohydrin produced. In equilibrium ether 0.2% / ₀

the apparatus was made of an aqueous glycerine 50 other substances 1.0%

dichlorohydrin solution with a concentration of

0.356 mol / l 500 liters per hour for the dissolution of the allyl chloride and 140 liters for the dissolution of the chlorine. With the in F i g. 3, glyci allyl chloride and chlorine were made the corresponding 55 rindichlorohydrin. At the equilibrium proportions of the aqueous solution with an addition rate of the arrangement were of an aqueous solution of 4.1 mol / h in each case. Furthermore, glycerol dichlorohydrin solution of 0,? ⁰ " ¹ mol / l 27 Ij 10.4 liters of water per hour were added to the apparatus for the dissolution of the allyl chloride and 19.7 l / h for d and the reaction was ^{carried out at 30 °} C. In this way, the chlorine was pumped around 10.7 liters of glycerol dichlorohydrin 60 The corresponding proportions of the solution were solution per hour The yield of glycerol dichloro-allyl chloride and chlorine in a respective amount of hydrin compared to the starting materials 1.02 mol / h and 1.00 mol / h. The ChI was 90.4 ° / _c . was absorbed at the ejector. The resulting 'Example 2 solution was divided into two equal parts, the de

65 tubular reactor were introduced. The rea

In a reaction according to Example 1, the capacitor consisted of a titanium alloy and was instructed

centering of the circulating glycerol dichlorohydrin diameter of 25.4 cm and a total length ν

solution within a range of 0.1 to 0.60 mol / l 20 m. The chlorine additions were made once to c

Eiiit opening of the tubular reactor as well as at a point which was 2 away from it in the direction of flow. With an hourly addition of 2.94 liters of water to the apparatus, the reaction was carried out at 40 ° C. In this way, glycene dichlorohydrin solution could be withdrawn as product at 2.94 l / h. The yield of glycerol dichlorohydrin relative to the starting materials was 95.0%. In relation to the allyl chloride used, trichloropropane and ether were formed as by-products in an amount of about 5%. As a comparative experiment, the reaction liquid with the dissolved chlorine was added to the reaction zone in one step. Here, one relatively to the starting materials received a 92.0 ° / _o yield from Glyzerindu.hlorhydrin. It was found that the length of the reactor used in this example had to be increased by a factor of 4/3 in order to obtain a glycerol dichlorohydrin yield of 95% by the above method - but with addition in one stage.

10

Example 5

With the same conditions as in Example 4, glycerol dichlorohydrin was produced. However, it became the aqueous chlorine solution divided into three equal parts before it was added to the reaction zone. the The chlorine was added at the inlet opening of the tubular reactor, one of which was 2 m in Point distant in the direction of flow, as well as at a point ^

ίο which was another 2 min flow direction away. With this arrangement, the glycene dichlorohydrin solution was withdrawn as product at 2.95 l / h. In relation to the starting substances, the yield of glycerol dichlorohydrin was 96%.

Further characterized in that wherein one wanted to obtain a Glyzerindichlorhydrinlösung with the same yield of 96 ° / ₀ and an arrangement in which the aqueous solution of chlorine is added in a stage of the reaction zone, the length of the reactor showed a

ao factor 3/2 would have to be increased.

1 sheet of drawings

Claims (6)

Patent claims: 1. A process for the preparation of glycerol dichlorohydrin c ireh reaction of allyl chloride with aqueous chlorine solution, characterized in that the allyl chloride is also used as an aqueous solution. 2. The method according to claim 1, characterized in that the aqueous chlorine solution in two to five stages is fed to the reaction zone. 3. The method according to claim 1 or 2, characterized in that the aqueous phase is circulated after the organic phase has been separated off. 4. Apparatus for performing the method najh claim 1, ^ -characterized by a storage vessel for receiving an aqueous reaction solution, a device for supplying water, an ejector to make chlorine in part of the d ^ m To dissolve the reaction liquid withdrawn from the storage vessel, a dissolving tank for the dissolution of Allyl chloride in another part of the reaction liquid withdrawn from the storage vessel, a reactor for reacting the aqueous chlorine solution with the aqueous allyl chloride solution, and Devices for withdrawing part of the reaction mixture. 5. Apparatus according to claim 4, characterized in that the Reaktoi is tubular. 6. Apparatus according to claim 5, characterized in that the tubular reactor with Devices is equipped to the coming from the ejector aqueous ChlorHsung in several To include levels.