CS216591B1 - Process for producing epichlorohydrin - Google Patents

Abstract

The invention relates to a method for producing epichlorohydrin. The invention consists in the epoxidation of allyl chloride being carried out with tert-butyl peroxide under heating in the presence of organomolybdenum compounds. The epoxidation is carried out at a temperature of 90 to 100 °C and a molar ratio of allyl chloride to tert-butyl peroxide of 6:1 to 10:1, and as organomolybdenum compounds, molybdenum carboxylate or complex molybdenum alkoxides are used, which are obtained by the reaction of molybdenum with tert-butyl peroxide in the presence of aliphatic alcohols with 1 to 4 carbon atoms at a temperature of 20 to 100 °C, in an amount of 2.10"^ atoms Mo/mol tert-butyl peroxide. The invention can be used in the synthesis of many chemical products, such as epoxy resins, synthetic glycerin, epichlorohydrin rubber, etc.

Description

The invention relates to a process for the preparation of eplchlorohydrin.

Epichlorohydrin is the raw material for a number of fragile products. It is used extensively for the production of epoxy resins, which are again used for the production of paints and paints resistant to moisture. Most of the produced eplchlorohydrin is used in the production of synthetic glycerin. The synthesis of epichlorohydrin rubbers, characterized by high resistance to heat and organic solvents, represents a positive direction for the widespread use of epichlorohydrin.

The only industrially realized process for producing epichlorohydrin is the chlorohydrin process.

One of the most important steps is the degree of reaction of allyl chloride and hypochlorous acid. The hypochlorous acid is produced by hydrolysis in the presence of alkali and / or vapenoe, respectively. which is used to neutralize the second product of the hydrolysis of chlorine, hydrochloric acid. The hypochlorous acid solution proceeds to the next step, to the step of producing glycerine dichlorohydrins. The synthesis of the dichlorohydrins is carried out with vigorous stirring of the hypochlorous acid solution with allyl chloride. The dichlorohydrin solution, which is first purified from the organic phase, is added to the dehydrochlorination step. The dehydrochlorination of dichlorohydrins is carried out by means of lime milk from heating. This gives epichlorohydrin as a raw material which contains a number of chlorinated organic admixtures. For the preparation of a commercial product, crude epichlorohydrin is rectified (L.A.OŠin Synthetic Glycerin Preparation, Moscow, Chimija 1974).

The chlorhydrin process for the synthesis of epichlorohydrin is characterized by a high yield of epichlorohydrin and its waxy quality. However, this process is characterized by an unproductive consumption of chlorine and the presence of large amounts of waste water (50 to 100 m per 1 ton of epichlorohydrin), which is contaminated with mineral and organic impurities, the removal of which is very costly.

*

Methods for producing epichlorohydrin by epoxidation with allyl chloride by peroxides are known. For example, a process for epoxidizing allyl chloride with ethylbenzene peroxide or tert-butyl peroxide at a temperature of 70-80 ° C in a molar ratio of allyl chloride to peroxide of 15:20 has been described. The epoxidation is carried out in the presence of catalysts, such as inorganic salts of molybdic acid or molybdenoorgenic compounds, for example acetonate, versate and di-tert-butyl molybdenum benzoate. The synthesis is carried out in a glass ampoule. In this process, the yield of epichlorohydrin, based on the amount of peroxide used, is only 25 to 45%, and a large dilution of the starting mixture with ellyl chloride at the selected molar ratio of allyl chloride to peroxide makes it difficult to separate epichlorohydrin from the reaction. Moscow Mendeleyev Institute, Series 74, 1973).

In another process for the preparation of epichlorohydrin, ellyl chloride is epoxidized with hydrocarbon peroxides at a temperature of 50 ° C (Japanese Patent Specification No. 17,649). The process is carried out in an organic solvent environment, for example benzene, in the presence of inorganic vanadium, molybdenum or tungsten compounds which are used as catalysts. In order to increase the yield of the final product, it is proposed to maintain a special temperature regime, which consists in precooling the starting mixture to below 10 ° C, and introducing calcium chloride and benzene into the cooled mixture.

In this process, epichlorohydrin is obtained in a yield of 96%. However, the peroxide conversion is only 47%. Furthermore, the use of calcium chloride and benzene leads to complications in the production stream, since the separation of the solvent and the recovery of waste in connection with the use of calcium chloride are necessary, and the presence of large amounts of unreacted peroxide in the reaction mixture increases the risk of explosion.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a process for the production of epichlorohydrin which makes it possible to produce the final product in high yield with a high peroxide conversion by a simple technology.

The object of the invention is to provide a target in the process for producing epichlorohydrin by epoxidation of allyl chloride. Butyl epoxide with heating in the presence of molybdenum organic compounds according to the invention is carried out at 90 to 105 ° C and at a molar ratio of allyl chloride to tert-butyl peroxide of 6: 1 to 10: 1 and molybdenum carboxylates or molybdenum complex salts are used as molybdenum compounds. which are obtained by reacting the molybdenum with t-butyl hydroperoxide in the presence of aliphatic alcohols having 1 to 4 carbon atoms at a temperature of 20-100 ° C in an amount of 2.10 ^- 5.10 y _and z "^ atoms of Mo / mole t-butyl peroxide.

As mentioned above, tert-butyl peroxide is used as the peroxidizing agent. The use of other organic peroxides, for example ethylbenzene peroxide or isopropylbenzene peroxide, causes a significant reduction in the yield of epichlorohydrin. This is related to the fact that the peroxides of olefins by peroxides are accompanied by a side reaction consisting in the cleavage of these peroxides. In the production of epichlorohydrin by epoxidation of allyl chloride, the rate of thermocatalytic cleavage of ethylbenzene peroxide or isopropylbenzene peroxide is greater than the rate of epoxidation of allyl chloride, therefore the epoxidation selectivity of this epoxidation process using these peroxides is low.

The selected molar ratio of allyl chloride to tert-butyl peroxide 6: 1 to 10: 1 provides for the preparation of a reaction mixture containing 6 to 10% of the final product, the conversion of tert-butyl peroxide being 90 to 95%. also peroxide conversion and process selectivity for epichlorohydrin, but the concentration of epichlorohydrin decreases, which complicates its isolation. At lower molar ratios of allyl chloride to tert-butyl peroxide, for example 4: 1 to 5: 1, the yield of epichlorohydrin is substantially reduced due to an increase in the side reaction rate of peroxide cleavage.

The epoxidation is carried out at a temperature of 90 to 105 ° C, preferably at 100 ° C. The temperature drop below 90 ° C is accompanied by a decrease in tert-butyl peroxide conversion and epichlorohydrin yield. Increasing the temperature above 105 ° C causes rapid thermocatalytic cleavage of tert-butyl peroxide with separation of alcohol and large temperature evolution. The yields of epichlorohydrin are close to zero.

Under these conditions, the concentration of molybdic organic compounds used as catalyst is 2.10-4.5-10.10 Mo / mol tert-butyl peroxide. When the amount of catalyst is reduced below the lowest limit, peroxide conversion as well as process selectivity is low.

- V

Increasing the amount of catalyst above 5.10% Mo / mol peroxide does not affect the yield of epichlorohydrin.

As mentioned above, molybdenum carboxylates or molybdenum salts which are obtained with tert-butyl peroxide in the presence of aliphatic alcohols having 1 to 4 carbon atoms at a temperature of 20 to 100 ° C are used as the molybdenum compounds.

The selected temperature range is optimal. As the temperature rises above 100 ° C, the rate of dissolution of molybdenum in the reaction partner mixture used in the preparation of the catalyst increases and there is a risk of explosion.

It is recommended that molybdenabietate, molybdenum acetate, molybdenum proponate and molybdenum stearate be used as molybdenum carboxylate.

Suitably, the so-called complex salt of mflybdenum, which aa obtains in the presence of 0.4 to 2.2% of water, based on the weight of the starting components involved in the preparation of the catalyst, is to be used.

The presence of water in this amount range accelerates the incorporation of molybdenum in the reaction partner mixture, reduces the fraction of tert-butyllepoxide cleavage, and increases catalyst activity.

The process for producing epichlorohydrin according to the invention makes it possible to produce epichlorohydrin in a yield of 60 to 60 mol. %, based on the peroxide reacted, at a peroxide conversion degree of 68 to 96%. The concentration of epichlorohydrin in the reaction products is 6 to 10% by weight.

Furthermore, in the process for producing the epichlorohydrin according to the invention, there is practically no waste water, since the epoxide of allyl chloride tert.butylepoxide does not require the use of lime milk which is converted into a dilute calcium chloride solution contaminated with organic impurities in a known manner.

According to the proposed process, in addition to epichlorohydrin, another commercial product, the target, is formed. Butyl alcohol. This can be used as a high-octane fuel additive, optionally processed to a highly pure isobutylene or tert-methyl tert-butyl ester. The tert-butyl tert-butyl ester is also a high-octane component, less hygroscopic than tert-butyl alcohol. Effective use of tert-butyl alcohol substantially increases the overall profitability of the process.

The process for the production of epichlorohydrin according to the invention is technologically simple and is carried out as follows.

The epoxidation of the ellyl chloride with tert-butyl peroxide is carried out in a reactor made of glass or nickel-molybdenum alloy. The reactor is equipped with a jacket and a heating nest. The reactor is heated by a heat carrier which circulates in the jacket. The reactants are introduced through a reactor neck provided with a lid. When using solid molybdenum carboxylates as catalyst ee, the reactor is placed in a swing to agitate the catalyst β by reaction. components and turns on ae heating. After completion of the reaction, the reactor was cooled rapidly and the resulting reaction mixture was removed. In order to isolate the final product, the reaction mixture is rectified.

The preparation of complex molybdenum salts is carried out in a four-liter flask equipped with a reflux condenser, stirrer and thermometer. Place the flask in a water bath. The flask was charged with tert-butyl peroxide, a C 1 -C 4 aliphatic alcohol and molybdenum and, if necessary, water. The contents of the flask are heated with stirring to a temperature of 20 to 100 ° C, and preferably to 50 to 70 ° C.

In order to better elucidate the invention, the following specific examples are set forth.

Example 1

17.5 g of ellylchloride, 3.45 g of tert-butyl peroxide (molar ratio of allyl chloride to peroxide of 6: 1) and 0.22 g of molybdenabietate (3.10 ^J ) are introduced into a nickel-molybdenum alloy rector equipped with a jacket and a heating nest. Mo / mol peroxide). The rector is maintained at 100 ° C for 60 minutes. The peroxide conversion is 75%, the yield of epichlorohydrin based on the reacted peroxide is 69% and the epichlorohydrin concentration in the reaction mixture corresponds to 8.3% by weight. %.

To demonstrate the capability of epoxidation of tert-butylepoxide, epoxidation of allyl chloride with various organic peroxides was performed under identical conditions.

17.5 g of ellyl chloride, 5.2 g of ethylbenzene peroxide (6: 1 molar ratio) and 0.12 g of molybdenoblethate (3.10 .mu.m Mo / mol peroxide) were charged to the nickel-molybdenum alloy reactor.

The reactor temperature is maintained at 100 ° C for 30 minutes, the peroxide conversion is 66%, the yield of epichlorohydrin, based on the unreacted peroxide, is 10%.

17.5 g of slyl chloride, 6 g of isopropylbenzene peroxide (6: 1 molar ratio) and 0.126 g of molybdenum resinate (3.10 < 4 > Mo / mol peroxide) are charged to the nickel-molybdenum alloy reactor.

The reactor was held at 100 ° C for 60 minutes. The peroxide conversion is 95%, the yield of epichlorohydrin based on the converted peroxide is zero.

Example 2 and the conditions of Example 1 were carried out with epoxidation of tolybutylepoxide using molybdenum resinate as the catalyst. The peroxide conversion is 69%, the yield of epichlorohydrin based on the converted peroxide is 71%. The concentration of epichlorohydrin in the reaction mixture is

8.2 wt. %.

Example 3

Under the conditions of Example 1, the allyl chloride is epoxidized with tert-butylepoxide and molyodestearate is used as the catalyst. The peroxide conversion was 72%, and the yield of epichlorohydrin, based on the peroxide reacted, was 69%. The concentration of epichlorohydrin in the reaction mixture was 8.3% by weight.

Example 4

Under the conditions of Example 1, the allyl chloride is epoxidized with tert-butyl peroxide using molybdenum proponate as the catalyst. The peroxide conversion is 70%, the yield of epichlorohydrin based on the converted peroxide is 71%. The concentration of epichlorohydrin in the reaction mixture was 8.4% by weight.

Example 5

Under the conditions of Example 1, the allyl chloride is epoxidized with tert-butyllepoxide using a complex molybdenum salt of 3.10 ^J Mo / mol peroxide as the catalyst, which is prepared by reacting 0.046 g of molybdenum with 15.8 g of tert-butylperoxide in the presence of 9. 3 g of ethanol and 0.8% water, based on the weight of the starting reactants used for the preparation of the catalyst, at a temperature of 70 ° C.

The peroxide conversion was 89.5%, the yield of epichlorohydrin, based on the peroxide reacted, was 63.3%.

Example 6

18.0 g of allyl chloride are introduced into a glass reactor equipped with a jacket and a heating nest,

4.33 g of tert-butyl peroxide (the molar ratio of allyl chloride to peroxide is 7.7: 1) and molybdenabietate in an amount of 3.10 .mu.m Mo / mol peroxide. The reactor was heated at 104.5 ° C for 45 minutes. The peroxide conversion is 87%, the yield of epichlorohydrin, based on the peroxide reacted, is 72%. The concentration of epichlorohydrin in the reaction mixture was 7.7 wt. %.

Example 7

A nickel-molybdenum alloy reactor with a jacket and a heating nest is introduced into the reactor

18.0 g of allyl chloride, 2.15 g of tert-butyl peroxide (the molar ratio of allyl chloride to peroxide is

10: 1) and 0.08 g of molybdenabenate (2.10? Mo / mol peroxide). The reactor was heated at 105 ° C for minutes. The peroxide conversion was 96%, the yield of epichlorohydrin based on the reacted peroxide was 61%. The concentration of epichlorohydrin in the reaction mixture was 6.4 wt. %.

Example 8

Into a nickel-molybdenum alloy reactor equipped with a plunger and a heating nest to introduce 18.0 g of allyl chloride, 3.45 g of tert-butyl peroxide (allyl chloride to peroxide molar ratio of 6 x 1) and 0.205 g of molybdenabietate (5.10 " Mo atoms) per mol of peroxide). The reactor was heated at 90 ° C for 60 minutes. The peroxide conversion is 68%, the yield of epiohlorohydrin based on the reacted peroxide is 73%, the concentration of epiohlorohydrin in the reaction mixture is 8.3% by weight. %.

Example 9

18.0 g of allyl chloride, 2.15 g of tert-butyl peroxide (molar ratio of allyl chloride to peroxide of 10) and 0.121 g of molybdenabietate (3.10 .mu.M atoms) are charged to a jacketed nickel-molybdenum reactor. mole peroxide). The reactor is heated at 105 ° C for 30 minutes. The peroxide conversion was 93%, the yield of epiohlorohydrin, based on the peroxide reacted, was 60%, the concentration of epichlorohydrin in the reaction mixture was 6 wt. %.

The following examples are given to demonstrate the effect of allyl chloride to peroxide molar ratio on peroxide conversion and epichlorohydrin yield.

Into a nickel-molybdenum alloy reactor equipped with a jacket and a heating nest to introduce 17.5 g of allyl chloride, 1.02 g of tert-butyl peroxide (the allyl chloride to peroxide molar ratio is 20 " 1) and 0.036 g of molybdenabenate (3.10 " Mo / mol peroxide). The reactor is heated at 100 ° C for 60 minutes. The peroxide conversion was 83%, the yield of epichlorohydrin based on the reacted peroxide was 76%, the epichlorohydrin concentration in the reaction mixture was 3.5% by weight.

18 g of allyl chloride are introduced into a glass reactor equipped with a jacket and a heating nest,

7.17 g of tert-butyl peroxide (the molar ratio of allyl chloride to peroxide is 4.65: 1) and molybdenum diethyl ether in an amount of 5.10 < 6 > Mo / mol peroxide. The reactor is held at 100 ° C for 30 minutes. The peroxide conversion was 87.6%, the yield of epichlorohydrin based on the reacted peroxide was 53%, the concentration of epichlorohydrin in the reaction mixture was 6.8 wt. %.

Example 10 and the conditions of Example 9 are epoxidized with allyl chloride t-butyl peroxide (allyl chloride to peroxide molar ratio of 10: 1), wherein ae is used as a complex aoli catalyst, which is obtained by dissolving 0.177 g of molybdenum metal in a 37.5 g of peroxide. 8 g of ethanol at 55 ° C in an amount of 3.10% Mo / mol peroxide. The peroxide conversion is 80.0%, the yield of epichlorohydrin, based on the peroxide reacted, is 49.5%.

Example 11

25.5 g of allyl chloride, 5 g of tert-butyl peroxide (6: 1 molar ratio of allyl chloride to peroxide) and 3.10 ^- 3 _{atoms of} Mo / mol are introduced into a nickel-molybdenum alloy reactor with a jacket and a heating nest. % of the molybdenum salt complex obtained by reacting 0.112 g of molybdenum and 38.8 g of tert-butyl peroxide in the presence of 20.5 g of methanol and 1% water, based on the weight of the starting reactants which are used to prepare the catalyst. The complex molybdenum salt is obtained at 20 ° C. The reactor is held at 100 ° C for 60 minutes. The peroxide conversion is 88%, the yield of epichlorohydrin, based on the peroxide reacted, is 65%.

Example 12

25.5 g of allyl chloride, 5 g of tert-butyl peroxide (6: 1 molar ratio of allyl chloride to peroxide) and 3.10 < 3 > Mo / mol peroxide complexes are introduced into a nickel-molybdenum alloy reactor with a jacket and heating nest. molybdenum salt, which is obtained by reacting 0.062 g of molybdenum with 20.6 g of tert-butyl peroxide in the presence of 6.3 g of propanol and 1% water, based on the weight of the starting reactants used in the preparation of the catalyst. The complex molybdenum salt is obtained at a temperature of 60 ° C. The reactor is held at 100 ° C for 60 minutes. The peroxide conversion is 90%, the yield of epichlorohydrin, based on the peroxide reacted, is 67%.

Example 13

Under the conditions of Example 1, the tert-butyl peroxide allyl chloride is epoxidized (the allyl chloride to peroxide molar ratio is 6: 1) using the complex salt obtained as a catalyst by dissolving 0.045 g of molybdenum metal in 15.6 g of tert-butyl peroxide and

9.5 g of ethanol at 100 [deg.] C. in the presence of 0.2% water, based on the weight of the reactants used in the preparation of the catalyst, in an amount of 3 * 10 < -1 > Mo / mol peroxide. The peroxide conversion was 60%, the yield of epichlorohydrin, based on the peroxide reacted, was 50%.

Example 14

Under the conditions of Example 1, the allyl chloride is epoxidized with tert-butyl peroxide (the molar ratio of allyl chloride to peroxide is 6: 1) using a complex salt as the catalyst, obtained by dissolving 0.048 g of molybdenum metal in a mixture of 15.9 g of tert-butylperoxide.

9.2 g of ethanol at 60 ° C in the presence of 4.2% water, based on the weight of the reactants used in the production of the catalyst, in an amount of 3.10 Mo / mol peroxide. The peroxide conversion was 79%, the yield of epichlorohydrin based on the reacted peroxide was 59%.

Example 15

Under the conditions of Example 1, tert-butyl peroxide is eloxidated (elution ratio of allyl chloride to peroxide is 6: 1) using a complex salt as the catalyst, obtained by dissolving 0.177 g of molybdenum metal in a mixture of 37.5 g of tert-butyl peroxide and

16.6 g of tert-butyl alcohol at 70 ° C, in the presence of 1% water, based on the weight of the reactants used in the preparation of the catalyst, in an amount of 3.10 Mo / mol peroxide. The peroxide conversion is 92%, the yield of epichlorohydrin based on the reacted peroxide is 69%.

Claims (6)

SUBJECT OF THE INVENTION A process for the preparation of epichlorohydrin by epoxidation of ellyl chloride with tert-butyl peroxide under heating in the presence of molybdenoorgic compounds, characterized in that the epoxidation of allyl chloride is carried out with tert-butyl peroxide at 90 to 105 ° C and a molar ratio of allyl chloride to tert-butylperoxide 6: 1 up to 10: 1 and molybdenocarboxylates or molybdenum complex salts, which are obtained by reacting molybdenum with tert-butyl peroxide in the presence of aliphatic alcohols having from 1 to 4 carbon atoms at 20 to 100 ° C, in an amount of 2.10 " t-butylperocide. 2. A process according to claim 1 wherein the molybdenum carboxylate is molybdenabietate. 3. The process of claim 1 wherein the molybdenum carboxylate is molybdenum resinate. 4. The process of claim 1 wherein the molybdenum carboxylate is molybdenocaproates. 5. The method of claim 1, wherein the ee of the stearate. 6. The process of claim 1, wherein ee is prepared in the presence of 0.4 to 2.2 water of the components used to obtain the catalyst. as molybdenum carboxylate used molybdenum used complex salts of molybdenum, based on the weight of the starting reaction Printed by Moravian Printing Works, provos 12, Leninova 21, Olomouc