Synthetic method of epichlorohydrin

Abstract

The invention discloses a synthetic method of epichlorohydrin, which at least comprises the following steps: introducing a homogeneous mixture containing chloropropene, hydrogen peroxide, polyol and an ionic surfactant into a continuous 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 method for synthesizing 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 is an important organic chemical raw material and fine chemical product with a wide range of uses. The epoxy resin made from it has the characteristics of strong adhesion, chemical corrosion resistance, low shrinkage, good chemical stability, high impact strength and excellent dielectric properties. It is widely used in coatings, adhesives, reinforcement materials, casting materials and electronic laminated products. After entering the 21st century, the application field of epoxy resin has been continuously expanded and the output has increased rapidly. my country is currently the world's largest production base of epoxy resin, and the demand for epichlorohydrin will become increasingly greater.

[0003] At present, the industrial production methods of ECH in the world mainly include propylene high temperature chlorination method, propylene acetate method and glycerol method. Among them, propylene high temperature chlorination method is the most important production method at home and abroad, while the glycerol method is expected to become the development direction of ECH technology in the future due to its economic and environmental protection. However, this method is affected by the price of glycerol, and the market price fluctuates greatly.

[0004] 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. The method originated in the 1980s, when the British Interox Chemical Company successfully synthesized epichlorohydrin by using peroxyacid and allyl chloride for epoxidation at 100-110°C. At present, the direct epoxidation of allyl chloride to prepare ECH generally uses hydrogen peroxide, peroxyacid, alkoxy hydroperoxide, molecular oxygen, etc. as oxygen sources for research. Among them, using hydrogen peroxide as an oxidant, Sinopec, Dalian Institute of Chemical Physics, Jiangsu Yangnong and other units have made great breakthroughs, and it is expected that multiple sets of equipment will be built in recent years. 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 large amount of energy to evaporate and recycle the solvents, which restricts the industrialization of the process in many ways. Summary of the invention

[0005] According to one aspect of the present application, a method for preparing epichlorohydrin is provided, which includes introducing an ionic surfactant and a polyol into a reaction system, making allyl chloride and hydrogen peroxide two phases form a homogeneous phase, and pumping them into a continuous reactor equipped with titanium silicon molecular sieve TS-1 through multiple metering pumps according to a certain molar ratio, realizing continuous operation, and directly epoxidizing allyl chloride to prepare epichlorohydrin. The method promotes the mixing of organic phase and aqueous phase by adding an ionic surfactant, 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 has energy-saving and environmentally friendly processes, simple equipment and process, high yield and selectivity of epichlorohydrin, and is suitable for large-scale industrial production of epichlorohydrin. At the same time, the method adopts multiple metering pumps to realize continuous production and simple operation. 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.

[0006] At least the following steps are included:

[0007] Passing a homogeneous mixture containing allyl chloride, hydrogen peroxide, a polyol and an ionic surfactant into a continuous reactor for reaction to obtain a product containing epichlorohydrin;

[0008] The continuous reactor is filled with a catalyst containing titanium silicon molecular sieve TS-1;

[0009] By introducing ionic surfactants and polyols into the reaction system, allyl chloride and hydrogen peroxide, the oil-water two phases, form a homogeneous phase, which is pumped into a continuous reactor filled with titanium silicalite TS-1 through multiple metering pumps according to a certain molar ratio, thus achieving continuous operation.

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

[0013] 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.

[0014] Optionally, the molar ratio of allyl chloride to polyol is 6 to 10:1;

[0015] Optionally, the molar ratio of allyl chloride to polyol is 8 to 10:1.

[0016] The molar ratio of allyl chloride to hydrogen peroxide is 1-10:1.

[0017] 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.

[0018] Optionally, the molar ratio of allyl chloride to hydrogen peroxide is 3 to 10:1;

[0019] Optionally, the molar ratio of allyl chloride to hydrogen peroxide is 5 to 10:1.

[0020] The molar ratio of the hydrogen peroxide to the ionic surfactant is 1 to 50:1.

[0021] 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.

[0022] Optionally, the molar ratio of the hydrogen peroxide to the ionic surfactant is 10 to 50:1;

[0023] Optionally, the molar ratio of the hydrogen peroxide solution to the ionic surfactant is 30 to 50:1.

[0024] The mass concentration of the hydrogen peroxide is 10-70%.

[0025] 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.

[0026] The reaction temperature is 20 to 90°C;

[0027] 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.

[0028] The reaction time is 1 to 10 hours;

[0029] Optionally, the reaction time is independently selected from any value among 1 hour, 2 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours or 10 hours, or any value therebetween.

[0030] The liquid phase flow rate of the reaction is 0.1 to 20 L / min.

[0031] Optionally, the liquid phase flow rate of the reaction is independently selected from any value among 0.1 L / min, 0.5 L / min, 1 L / min, 3 L / min, 5 L / min, 9 L / min, 12 L / min, 15 L / min or 20 L / min or any value therebetween.

[0032] The anionic surfactant is selected from at least one of stearic acid and sodium dodecylbenzene sulfonate;

[0033] The cationic surfactant is selected from at least one of an amine salt type cationic surfactant and a heterocyclic type cationic surfactant;

[0034] 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;

[0035] 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.

[0036] The zwitterionic surfactant is selected from at least one of lecithin-type, amino acid-type and betaine-type zwitterionic surfactants.

[0037] The amine salt type cationic surfactant is selected from at least one of a quaternary ammonium salt type cationic surfactant, a primary amine salt type cationic surfactant, a secondary amine salt type cationic surfactant, and a tertiary amine salt cationic surfactant;

[0038] The heterocyclic cationic surfactant is selected from at least one of nitrogen-containing morpholine ring cationic surfactants, pyridine ring cationic surfactants, imidazole ring cationic surfactants, piperazine ring cationic surfactants, and quinoline ring cationic surfactants.

[0039] The titanium silicate molecular sieve TS-1 is a titanium-doped silicon-based zeolite molecular sieve.

[0040] The titanium silicate molecular sieve TS-1 has an MFI type topological structure.

[0041] The beneficial effects of this application include:

[0042] (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.

[0043] (2) By adding ionic surfactants and polyols, the organic phase and the aqueous phase are promoted to mix into a homogeneous phase, thereby improving the selectivity of the reaction. There is no need to add a large amount of solvent as in the traditional process. The reaction liquid after the reaction is clear and transparent, avoiding energy-intensive processes such as solvent evaporation and recovery.

[0044] (3) The process is energy-saving and environmentally friendly, the equipment and process are 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 this method has great economic benefits.

[0045] (4) There is no need for the traditional energy-intensive solvent evaporation and recovery process, which is conducive to industrial production expansion, low equipment maintenance cost, low system cost, low environmental pollution, simple operation, easy to repeat, and can efficiently produce epichlorohydrin. DETAILED DESCRIPTION

[0046] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0047] Unless otherwise specified, the raw materials in the examples of this application were purchased through commercial channels.

[0048] The analysis method in the examples of this application is as follows:

[0049] 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.

[0050] The epichlorohydrin selectivity and hydrogen peroxide utilization rate are detected by gas chromatography.

[0051] 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.

[0052] Example 1

[0053] Use multiple metering pumps to pump propylene chloride: 25% mass concentration hydrogen peroxide: ionic surfactant sodium dodecylbenzene sulfonate: ethylene glycol in a molar ratio of 50:5:2:2 into a continuous reactor equipped with titanium silicon molecular sieve TS-1 catalyst. Pass through the heat exchanger at a flow rate of 10L / min, heat to 45°C, and react for 7 hours. After the reaction, take a small amount of reaction liquid for gas chromatography analysis and hydrogen peroxide cerium sulfate titration. The results show that the conversion rate of hydrogen peroxide is 96.2%, the utilization rate of hydrogen peroxide is 97%, and the selectivity of epichlorohydrin is 98.1%.

[0054] Example 2

[0055] A continuous reactor containing titanium silicon molecular sieve TS-1 catalyst was pumped into the reactor using multiple metering pumps at a molar ratio of 100:10:1:10 for allyl chloride: 50% mass concentration hydrogen peroxide: ionic surfactant sodium stearate: pentaerythritol. The reaction was conducted through a heat exchanger at a flow rate of 12 L / min, and the temperature was raised to 50°C. The reaction time was 8 hours. 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 97.1%, the utilization rate of hydrogen peroxide was 97%, and the selectivity of epichlorohydrin was 96.3%.

[0056] Embodiments 3 to 11

[0057] 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.

[0058] Table 1 Raw material composition, ratio, reaction conditions and reaction results of Examples 3 to 11

[0059]

[0060] The test results of epichlorohydrin in other embodiments are similar to those described above, and epichlorohydrin is obtained by the present invention.

[0061] Example 12

[0062] Use multiple metering pumps to pump allyl chloride: 35% mass concentration hydrogen peroxide: ionic surfactant sodium dodecylbenzene sulfonate: sorbitol in a molar ratio of 50:5:1:5 into a continuous reactor equipped with titanium silicon molecular sieve TS-1 catalyst. Pass through the heat exchanger at a flow rate of 10L / min, heat to 50°C, and react continuously for 6 hours. After the reaction, take a small amount of the reaction liquid for gas chromatography analysis and cerium sulfate titration of hydrogen peroxide. The results show that the conversion rate of hydrogen peroxide is 97.2%, the utilization rate of hydrogen peroxide is 97%, and the selectivity of epichlorohydrin is 96.8%.

[0063] Comparative Example 1

[0064] The same reaction conditions as in Example 12 were adopted, and no surfactant and polyol were added. The specific operation was as follows: a continuous reactor containing titanium silicon molecular sieve TS-1 catalyst was pumped into the reactor using multiple metering pumps according to a molar ratio of 50:5 of allyl chloride and 35% mass concentration hydrogen peroxide. The reactor passed through a heat exchanger at a flow rate of 10 L / min, and the temperature was raised to 50°C. The continuous reaction time was 6 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 73.5%, the utilization rate of hydrogen peroxide was 75%, and the selectivity of epichlorohydrin was 91.2%.

[0065] Embodiment 13

[0066] Use multiple metering pumps to pump propylene chloride: 50% mass concentration hydrogen peroxide: ionic surfactant cetyl alcohol sulfate: polyethylene glycol 200 in a molar ratio of 35:5:1:5 into a continuous reactor equipped with titanium silicon molecular sieve TS-1 catalyst. Pass through the heat exchanger at a flow rate of 10L / min, heat to 65°C, and react continuously for 5 hours. After the reaction, take a small amount of the reaction liquid for gas chromatography analysis and hydrogen peroxide cerium sulfate titration method. The results show that the hydrogen peroxide conversion rate is 94.7%, the hydrogen peroxide utilization rate is 97%, and the epichlorohydrin selectivity is 96.3%.

[0067] Comparative Example 2

[0068] The same reaction conditions as in Example 13 were adopted, but no ionic surfactant and polyol were added to the reaction, and methanol was added as the organic phase. The specific operation was as follows: a continuous reactor containing titanium silicon molecular sieve TS-1 catalyst was pumped into the reaction using multiple metering pumps according to a molar ratio of 35:5:500 of allyl chloride: 50% mass concentration hydrogen peroxide: methanol. The reaction was passed through a heat exchanger at a flow rate of 10 L / min, and the temperature was raised to 65°C. The continuous reaction time was 5 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 83.9%, the utilization rate of hydrogen peroxide was 89%, and the selectivity of epichlorohydrin was 92.7%.

[0069] 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 method for synthesizing 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 continuous reactor for reaction to obtain a product containing epichlorohydrin; The continuous 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 molar ratio of allyl chloride to polyol is 5 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 1 to 50:

1.

3. 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 3 to 10:1; The molar ratio of the hydrogen peroxide to the ionic surfactant is 10 to 50:

1.

4. 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.

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

6. The method according to claim 1, characterized in that The reaction temperature is 20 to 90°C; The reaction time is 1 to 10 hours; The liquid phase flow rate of the reaction is 0.1 to 20 L / min.

7. 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.

8. 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.

9. The method according to claim 8, characterized in that The amine salt type cationic surfactant is selected from at least one of a quaternary ammonium salt type cationic surfactant, a primary amine salt type cationic surfactant, a secondary amine salt type cationic surfactant, and a tertiary amine salt cationic surfactant; The heterocyclic cationic surfactant is selected from at least one of nitrogen-containing morpholine ring cationic surfactants, pyridine ring cationic surfactants, imidazole ring cationic surfactants, piperazine ring cationic surfactants, and quinoline ring cationic surfactants.

10. 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.

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