Process for preparing epoxy chloropropane

Abstract

The invention discloses a process for preparing epichlorohydrin, which comprises the following steps: introducing a homogeneous mixture containing chloropropene, hydrogen peroxide, polyol and an ionic surfactant into a fixed bed reactor for reaction to obtain a product containing epichlorohydrin. Compared with a traditional method, the method has the advantages that few reaction byproducts are produced, a product after hydrogen peroxide reaction is water, the ionic surfactant and the polyol are added, an organic phase and a water phase are promoted to be mixed into a homogeneous phase, the selectivity is improved, a large amount of solvent does not need to be added, the processes such as solvent evaporation and recovery are avoided, the process is energy-saving and environment-friendly, the equipment process is simple, the yield and the selectivity are high, and the method is suitable for industrial production. The method is suitable for industrial large-scale production, has relatively large economic benefits, does not need solvent evaporation and recovery, is beneficial to industrial production amplification, is low in equipment maintenance cost, relatively low in system cost, small in environmental pollution, simple to operate and easy to repeat, and can be used for efficiently producing the epichlorohydrin.

Description

Technical Field

[0001] The present application relates to a process for preparing epichlorohydrin, which uses hydrogen peroxide as an oxygen source and titanium silicon molecular sieve TS-1 as a catalyst to catalyze direct oxidation of allyl chloride to prepare epichlorohydrin, and belongs to the field of preparation and synthesis of epichlorohydrin. Background Art

[0002] Epichlorohydrin (ECH) is an important organic chemical raw material and an important intermediate in petrochemical industry. It is mainly used in the production of epoxy resin, glycerol, epichlorohydrin rubber and other derivatives. It can also be used as a solvent, plasticizer, flame retardant and surfactant.

[0003] At present, the main production processes of epichlorohydrin are the glycerol method, the propylene high temperature chlorination method (referred to as the propylene method) and the new hydrogen peroxide method. In terms of production capacity, the glycerol method is the main one, the propylene method is the auxiliary one, and the hydrogen peroxide method has the lowest overall share.

[0004] Although the process of producing epichlorohydrin by high-temperature chlorination of propylene is mature, it has disadvantages such as severe equipment corrosion, high energy consumption, high chlorine consumption, and low conversion rate. Under the situation of increasingly stringent environmental protection requirements, this method of producing epichlorohydrin has been included in the restricted category of the "Guidelines for Industrial Structure Adjustment".

[0005] The new process of preparing epichlorohydrin by direct oxidation with hydrogen peroxide is an emerging process and the most environmentally friendly production process of epichlorohydrin so far. The new green process will surely lead the future development of epichlorohydrin. However, in the current process, more solvents are usually used to dissolve the reaction raw material allyl chloride and the oxidant hydrogen peroxide to form a homogeneous phase. If the solvent is less, the two phases cannot be fully dissolved, which is not conducive to the mass transfer and heat transfer process, increases the occurrence of side reactions, and reduces the yield and selectivity of epichlorohydrin. However, the use of solvents, on the one hand, increases the cost of production, and on the other hand, requires a lot of energy to evaporate and recycle the solvent, which restricts the industrialization process of the process in many aspects. Summary of the invention

[0006] According to one aspect of the present application, a method for preparing epichlorohydrin is provided, which includes adding an ionic surfactant and a polyol to a reaction system, so that allyl chloride and hydrogen peroxide, which are oil-water phases, form a homogeneous phase, and pumping it into a fixed bed reactor equipped with titanium silicon molecular sieve TS-1 through a metering pump, and directly epoxidizing allyl chloride to obtain the epichlorohydrin. The method promotes the mixing of the organic phase and the aqueous phase by adding an ionic surfactant and a polyol, does not require a large amount of solvent added in the traditional process, avoids a large amount of energy-consuming processes such as solvent evaporation and recovery, and the process is energy-saving and environmentally friendly, the equipment process is simple, the yield and selectivity of epichlorohydrin are high, and it is suitable for large-scale industrial production of epichlorohydrin. The solvent-free synthesis system used in the method has greater economic benefits, lower system cost, less environmental pollution, simple operation, easy to repeat, low equipment maintenance cost, and can efficiently produce epichlorohydrin.

[0007] At least the following steps are included:

[0008] Passing a homogeneous mixture containing allyl chloride, hydrogen peroxide, polyol and ionic surfactant into a fixed bed reactor for reaction to obtain a product containing epichlorohydrin;

[0009] The fixed bed reactor is filled with a catalyst containing titanium silicon molecular sieve TS-1;

[0010] The polyol is selected from at least one of ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,6-hexanediol, polyethylene glycol 200, polyethylene glycol 400, polyethylene glycol 600, polyethylene glycol 800, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, terephthalate, glycerol, trimethylolpropane, pentaerythritol, xylitol or sorbitol;

[0011] The ionic surfactant is selected from at least one of anionic surfactants, cationic surfactants and zwitterionic surfactants.

[0012] The anionic surfactant is selected from at least one of stearic acid and sodium dodecylbenzene sulfonate;

[0013] The cationic surfactant is selected from at least one of an amine salt type cationic surfactant and a heterocyclic type cationic surfactant;

[0014] The amine salt type cationic surfactant is selected from at least one of quaternary ammonium salt type, primary amine salt, secondary amine salt and tertiary amine salt cationic surfactants;

[0015] The heterocyclic cationic surfactant is selected from at least one of nitrogen-containing heterocyclic cationic surfactants of morpholine ring, pyridine ring, imidazole ring, piperazine ring and quinoline ring.

[0016] The zwitterionic surfactant is selected from at least one of lecithin-type, amino acid-type and betaine-type zwitterionic surfactants.

[0017] The titanium silicate molecular sieve TS-1 is a titanium-doped silicon-based zeolite molecular sieve.

[0018] The titanium silicalite molecular sieve TS-1 has an MFI type topological structure.

[0019] The reaction temperature is 20 to 90°C;

[0020] Optionally, the reaction temperature is independently selected from any value of 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C or any value therebetween.

[0021] The feed mass space velocity of the reaction is 0.5 to 10 h -1 .

[0022] Optionally, the feed mass space velocity of the reaction is independently selected from 0.5h -1 , 1h -1 , 1.5h -1 , 2h -1 , 2.5h -1 , 3h -1 , 3.5h -1 , 4h -1 , 4.5h -1 , 5h -1 , 5.5h -1 , 6h -1 , 6.5h -1 , 7h -1 , 7.5h -1 , 8h -1 , 8.5h -1 , 9h -1 , 9.5h -1 or 10h -1 Any value in between or any value in between.

[0023] The molar ratio of the propylene chloride to the polyol is 5 to 10:1.

[0024] Optionally, the molar ratio of allyl chloride to polyol is independently selected from any of 5:1, 6:1, 7:1, 8:1, 9:1 or 10:1 or any value therebetween.

[0025] Optionally, the molar ratio of allyl chloride to polyol is 6 to 10:1;

[0026] Optionally, the molar ratio of allyl chloride to polyol is 8 to 10:1.

[0027] The molar ratio of allyl chloride to hydrogen peroxide is 1-10:1.

[0028] Optionally, the molar ratio of allyl chloride to hydrogen peroxide is independently selected from any value of 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1 or 10:1 or any value therebetween.

[0029] Optionally, the molar ratio of allyl chloride to hydrogen peroxide is 3 to 10:1;

[0030] Optionally, the molar ratio of allyl chloride to hydrogen peroxide is 5 to 10:1.

[0031] The molar ratio of the hydrogen peroxide to the ionic surfactant is 1 to 50:1.

[0032] Optionally, the molar ratio of hydrogen peroxide to the ionic surfactant is independently selected from any value of 1:1, 2:1, 3:1, 5:1, 10:1, 15:1, 20:1, 30:1, 40:1 or 50:1 or any value therebetween.

[0033] Optionally, the molar ratio of the hydrogen peroxide to the ionic surfactant is 10 to 50:1;

[0034] Optionally, the molar ratio of the hydrogen peroxide solution to the ionic surfactant is 30 to 50:1.

[0035] The mass concentration of the hydrogen peroxide is 10-70%.

[0036] Optionally, the mass concentration of the hydrogen peroxide is independently selected from any value of 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70% or any value therebetween.

[0037] The beneficial effects of this application include:

[0038] (1) The present application provides a method for preparing epichlorohydrin. Compared with the traditional method, the preparation process of the present invention uses titanium silicon molecular sieve TS-1 as a catalyst and hydrogen peroxide as an oxygen source to directly oxidize allyl chloride to epichlorohydrin. There are fewer reaction by-products, and the product after the hydrogen peroxide reaction is water, which has little pollution to the environment and is green and environmentally friendly.

[0039] (2) The present application provides a method for preparing epichlorohydrin, which does not require the traditional energy-intensive solvent evaporation and recovery process, is conducive to industrial production scale-up, has low equipment maintenance costs, low system costs, little environmental pollution, is simple to operate, is easy to repeat, and can efficiently produce epichlorohydrin.

[0040] (3) The present application provides a method for preparing epichlorohydrin, which promotes the mixing of the organic phase and the aqueous phase into a homogeneous phase by adding an ionic surfactant and a polyol, thereby improving the selectivity of the reaction. It does not require the large amount of solvent added in the traditional process, and the reaction liquid after the reaction is clear and transparent, avoiding a lot of energy-consuming processes such as solvent evaporation and recovery.

[0041] (4) The present application provides a method for preparing epichlorohydrin, which is energy-saving and environmentally friendly, has simple equipment and process, high yield and selectivity of epichlorohydrin, and is suitable for large-scale industrial production of epichlorohydrin. The solvent-free synthesis system used in the method has great economic benefits. DETAILED DESCRIPTION

[0042] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0043] Unless otherwise specified, the raw materials in the examples of this application were purchased through commercial channels.

[0044] The analysis method in the examples of this application is as follows:

[0045] The selectivity of epoxy chloropropylene and the utilization rate of hydrogen peroxide during the reaction were detected using a gas chromatograph model 7890A produced by Agilent Technologies.

[0046] The epichlorohydrin selectivity and hydrogen peroxide utilization rate are detected by gas chromatography.

[0047] The detection of the hydrogen peroxide conversion rate adopts the cerium sulfate titration method, using o-phenanthroline ferrous iron as an indicator, and the titration end point is that the light red solution changes to a transparent light blue.

[0048] Example 1

[0049] Use a metering pump at an air velocity of 3.0h -1 A mixed solution of allyl chloride, 30% mass concentration of hydrogen peroxide, sodium dodecylbenzene sulfonate and polyethylene glycol 200 was pumped into a fixed bed reactor equipped with titanium silicalite TS-1 catalyst at a molar ratio of allyl chloride: hydrogen peroxide: ionic surfactant of 50:5:1:5, and the temperature was raised to 40°C. After the reaction, a small amount of reaction liquid was taken for gas chromatography analysis and cerium sulfate titration of hydrogen peroxide. The results showed that the hydrogen peroxide conversion rate was 93.1%, the hydrogen peroxide utilization rate was 94%, and the epichlorohydrin selectivity was 96.3%.

[0050] Example 2

[0051] Use a metering pump at an air velocity of 2.0h -1 A mixed solution of allyl chloride, 35% mass concentration of hydrogen peroxide, sodium stearate, and ethylene glycol was pumped into a fixed bed reactor equipped with titanium silicon molecular sieve TS-1 catalyst according to a molar ratio of allyl chloride: hydrogen peroxide: ionic surfactant of 100:10:1:10, and the temperature was raised to 65° C. After the reaction, a small amount of the reaction liquid was taken for gas chromatography analysis and cerium sulfate titration of hydrogen peroxide. The results showed that the conversion rate of hydrogen peroxide was 97.2%, the utilization rate of hydrogen peroxide was 97%, and the selectivity of epichlorohydrin was 98.3%.

[0052] Embodiments 3 to 11

[0053] The specific ingredient types, materials and reaction conditions are shown in Table 1 below. Other operations during the synthesis process are the same as in Example 1.

[0054] Table 1 Raw material composition, ratio, reaction conditions and reaction results of Examples 3 to 11

[0055]

[0056]

[0057] The test results of epichlorohydrin in other embodiments are similar to those described above, and epichlorohydrin is obtained by the present invention.

[0058] Example 12

[0059] Use a metering pump at an air velocity of 3.0h -1 A mixed solution of allyl chloride, 45% mass concentration of hydrogen peroxide, sodium dodecylbenzene sulfonate, and hexylene glycol was pumped into a fixed bed reactor equipped with titanium silicon molecular sieve TS-1 catalyst at a molar ratio of allyl chloride: hydrogen peroxide: ionic surfactant: polyol of 50:5:1:2, and the temperature was raised to 50° C. After the reaction, a small amount of the reaction liquid was taken for gas chromatography analysis and hydrogen peroxide cerium sulfate titration method, and the results showed that the hydrogen peroxide conversion rate was 98.3%, the hydrogen peroxide utilization rate was 97%, and the epichlorohydrin selectivity was 96.8%.

[0060] Comparative Example 1

[0061] The same reaction conditions as in Example 12 were used, but no surfactant and polyol were added. The specific operation was as follows: a metering pump was used at a space velocity of 3.0 h -1A mixed solution of allyl chloride and 45% mass concentration of hydrogen peroxide was pumped into a fixed bed reactor equipped with titanium silicon molecular sieve TS-1 catalyst at a molar ratio of allyl chloride: hydrogen peroxide of 50:5, and the temperature was raised to 50°C. After the addition, it was water-oil two-phase, and after stirring, it was a turbid liquid. The temperature was raised to 50°C, and the reaction time was 1 hour. After the reaction was completed, a small amount of the reaction liquid was taken for gas chromatography analysis and cerium sulfate titration of hydrogen peroxide. The results showed that the conversion rate of hydrogen peroxide was 82.5%, the utilization rate of hydrogen peroxide was 72%, and the selectivity of epichlorohydrin was 85.4%.

[0062] Embodiment 13

[0063] Use a metering pump at an air velocity of 10.0h -1 A mixed solution of allyl chloride, 40% mass concentration of hydrogen peroxide, cetyl alcohol phosphate, and glycerol was pumped into a fixed bed reactor equipped with titanium silicon molecular sieve TS-1 catalyst at a molar ratio of allyl chloride: hydrogen peroxide: ionic surfactant: polyol of 10:1:1:1, and the temperature was raised to 60°C. The reaction time was 3 hours. After the reaction was completed, a small amount of the reaction liquid was taken for gas chromatography analysis and hydrogen peroxide cerium sulfate titration method. The results showed that the hydrogen peroxide conversion rate was 94.5%, the hydrogen peroxide utilization rate was 98%, and the epichlorohydrin selectivity was 94.3%.

[0064] Comparative Example 2

[0065] The same reaction conditions as in Example 13 were used, but no ionic surfactant and polyol were added to the reaction. Methanol was added to the organic phase. The specific operation was as follows: a metering pump was used at a space velocity of 8.0 h -1 A mixed solution of allyl chloride, 40% mass concentration of hydrogen peroxide and methanol was pumped into a fixed bed reactor equipped with titanium silicon molecular sieve TS-1 catalyst at a molar ratio of allyl chloride: hydrogen peroxide: methanol of 10:1:50, and the temperature was raised to 60°C. The reaction time was 3 hours. After the reaction was completed, a small amount of the reaction liquid was taken for gas chromatography analysis and cerium sulfate titration of hydrogen peroxide. The results showed that the conversion rate of hydrogen peroxide was 89.3%, the utilization rate of hydrogen peroxide was 92%, and the selectivity of epichlorohydrin was 91.3%.

[0066] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A process for preparing epichlorohydrin, characterized in that: At least the following steps are included: Passing a homogeneous mixture containing allyl chloride, hydrogen peroxide, polyol and ionic surfactant into a fixed bed reactor for reaction to obtain a product containing epichlorohydrin; The fixed bed reactor is filled with a catalyst containing titanium silicon molecular sieve TS-1; The polyol is selected from at least one of ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,6-hexanediol, polyethylene glycol 200, polyethylene glycol 400, polyethylene glycol 600, polyethylene glycol 800, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, terephthalate, glycerol, trimethylolpropane, pentaerythritol, xylitol or sorbitol; The ionic surfactant is selected from at least one of anionic surfactants, cationic surfactants and zwitterionic surfactants.

2. The method according to claim 1, characterized in that: The anionic surfactant is selected from at least one of stearic acid and sodium dodecylbenzene sulfonate.

3. The method according to claim 1, characterized in that The cationic surfactant is selected from at least one of an amine salt type cationic surfactant and a heterocyclic type cationic surfactant.

4. The method according to claim 3, characterized in that The amine salt type cationic surfactant is selected from at least one of quaternary ammonium salt type, primary amine salt, secondary amine salt and tertiary amine salt cationic surfactants; The heterocyclic cationic surfactant is selected from at least one of nitrogen-containing heterocyclic cationic surfactants of morpholine ring, pyridine ring, imidazole ring, piperazine ring and quinoline ring.

5. The method according to claim 1, characterized in that The zwitterionic surfactant is selected from at least one of lecithin type, amino acid type and betaine type zwitterionic surfactants.

6. The method according to claim 1, characterized in that The reaction temperature is 20 to 90°C; The feed mass space velocity of the reaction is 0.5 to 10 h -1 .

7. The method according to claim 1, characterized in that The molar ratio of allyl chloride to polyol is 5 to 10:1; The molar ratio of allyl chloride to hydrogen peroxide is 3 to 10:1; The molar ratio of the hydrogen peroxide to the ionic surfactant is 1 to 50:

1.

8. The method according to claim 1, characterized in that The molar ratio of allyl chloride to polyol is 6 to 10:1; The molar ratio of allyl chloride to hydrogen peroxide is 1 to 10:1; The molar ratio of the hydrogen peroxide to the ionic surfactant is 10 to 50:

1.

9. The method according to claim 1, characterized in that: The molar ratio of allyl chloride to polyol is 8 to 10:1; The molar ratio of allyl chloride to hydrogen peroxide is 5 to 10:1; The molar ratio of the hydrogen peroxide to the ionic surfactant is 30-50:

1.

10. The method according to claim 1, characterized in that The mass concentration of the hydrogen peroxide is 10-70%.

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