Method for preparing epoxy chloropropane

Abstract

The invention discloses a method for preparing epichlorohydrin, which at least comprises the following steps: reacting a mixture containing chloropropene, hydrogen peroxide, polyol, a catalyst and an ionic surfactant in an intermittent tank reactor 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 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, glycerin, epichlorohydrin rubber and other derivatives. It can also be used as a solvent, plasticizer, flame retardant and surfactant. At present, the main production processes of epichlorohydrin are glycerin method, propylene high temperature chlorination method (referred to as propylene method) and new hydrogen peroxide method. In terms of production capacity share, glycerin method is the main one, propylene method is the auxiliary one, and hydrogen peroxide method has the lowest overall share.

[0003] 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".

[0004] The glycerol production process has the advantages of mild reaction conditions, high selectivity and yield, less pollution, and consumes a large amount of by-product hydrogen chloride, which is in line with the existing national industrial policy. However, with the continuous release of new domestic glycerol-based epichlorohydrin production capacity, the demand for glycerol has continued to increase, thus supporting the glycerol market trend. In 2021, the price of 99.5% glycerol once climbed to a high level of 14,000 yuan / ton, resulting in a sharp increase in the cost of the glycerol method. The glycerol-based epichlorohydrin is in a high-cost and low-profit state, and even in a loss-making state in some stages. In the long run, most of the later (planned) projects under construction are glycerol-based, and the demand is in a state of growth. The price of glycerol may be difficult to return to the previous low level of three or four thousand, so the gross profit margin of glycerol-based epichlorohydrin may be at a relatively low level.

[0005] The new process of preparing epichlorohydrin by 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 comprises using titanium silicon molecular sieve TS-1 as a catalyst, and directly epoxidizing allyl chloride in the presence of allyl chloride, hydrogen peroxide, polyols and ionic surfactants using an intermittent reactor 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. The polyol 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] A mixture containing allyl chloride, hydrogen peroxide, polyol, catalyst and ionic surfactant is reacted in a batch reactor to obtain a product containing epichlorohydrin;

[0009] The catalyst contains 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, and 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 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;

[0017] 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.

[0018] The zwitterionic surfactant is selected from at least one of lecithin-type, amino acid-type and betaine-type zwitterionic surfactants.

[0019] The molar ratio of the hydrogen peroxide to the ionic surfactant is 1 to 50:1.

[0020] 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.

[0021] Optionally, the molar ratio of the hydrogen peroxide to the ionic surfactant is 10 to 50:1;

[0022] Optionally, the molar ratio of the hydrogen peroxide solution to the ionic surfactant is 30 to 50:1.

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

[0032] 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.

[0033] The titanium silicate molecular sieve TS-1 is a titanium-doped silicon-based zeolite molecular sieve.

[0034] The titanium silicate molecular sieve TS-1 has an MFI type topological structure.

[0035] The mass of the catalyst is 0.1-10 wt % of the mass of allyl chloride.

[0036] Optionally, the mass of the catalyst is any value of 0.1wt%, 0.5wt%, 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt% or 10wt% of the mass of allyl chloride, or any value therebetween.

[0037] Optionally, the mass of the catalyst is 1 to 10 wt% of the mass of allyl chloride;

[0038] Optionally, the mass of the catalyst is 5-10 wt % of the mass of allyl chloride.

[0039] The reaction temperature is 20 to 90°C;

[0040] 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.

[0041] The reaction time is 1 to 10 hours.

[0042] 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.

[0043] After the reaction is completed, a certain amount of the reaction liquid is taken to test the selectivity of epichlorohydrin and the conversion rate and utilization rate of hydrogen peroxide.

[0044] Optionally, the detection methods used are gas chromatography and hydrogen peroxide liquid phase titration.

[0045] Optionally, the conversion rate of hydrogen peroxide during the reaction is greater than 95%.

[0046] Optionally, the utilization rate of hydrogen peroxide during the reaction is greater than 95%.

[0047] Optionally, the selectivity of epichlorohydrin during the reaction is between 95% and 99%.

[0048] The beneficial effects of this application include:

[0049] (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. In an intermittent reactor, allyl chloride is directly oxidized to epichlorohydrin. There are fewer reaction by-products. The product after the hydrogen peroxide reaction is water, which has little pollution to the environment and is green and environmentally friendly.

[0050] (2) 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.

[0051] (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.

[0052] (4) 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. DETAILED DESCRIPTION

[0053] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0054] Unless otherwise specified, the raw materials in the examples of this application were purchased through commercial channels.

[0055] The analysis method in the examples of this application is as follows:

[0056] 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.

[0057] The epichlorohydrin selectivity and hydrogen peroxide utilization rate are detected by gas chromatography.

[0058] 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.

[0059] Example 1

[0060] 5g of propylene chloride, 3g of 35% mass concentration of hydrogen peroxide, 1g of titanium silicon molecular sieve TS-1 catalyst, 0.2g of sodium dodecylbenzene sulfonate, and 0.5g of ethylene glycol were added to a batch reactor and heated to 45°C under stirring. The reaction time was 2 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 99.2%, the utilization rate of hydrogen peroxide was 96%, and the selectivity of epichlorohydrin was 98.2%.

[0061] Example 2

[0062] 40g of propylene chloride, 12g of 50% mass concentration of hydrogen peroxide, 1.5g of titanium silicon molecular sieve TS-1 catalyst, 2.5g of potassium cetyl phosphate, and 5g of polyethylene glycol 200 were added to a batch reactor and heated to 80°C under stirring, and the reaction time was 3 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 97.2%, the utilization rate of hydrogen peroxide was 97%, and the selectivity of epichlorohydrin was 98.3%.

[0063] Embodiments 3 to 11

[0064] 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.

[0065] Table 1 Raw material composition, ratio, reaction conditions and reaction results of Examples 3 to 11

[0066]

[0067]

[0068] The test results of epichlorohydrin in other examples were similar to those described above, and products containing epichlorohydrin were obtained.

[0069] Example 12

[0070] 30g of propylene chloride, 5g of 35% mass concentration of hydrogen peroxide, 1.0g of titanium silicon molecular sieve TS-1 catalyst, 2g of sodium dodecylbenzene sulfonate, and 5g of ethylene glycol were added to a batch reactor and heated to 50°C under stirring. The reaction time was 2 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 98.2%, the utilization rate of hydrogen peroxide was 96%, and the selectivity of epichlorohydrin was 96.4%.

[0071] Comparative Example 1

[0072] For comparison, the same reaction conditions as in Example 12 were used, and no surfactant and polyol were added. The specific operation was as follows: 30 g of chloropropylene, 5 g of 35% mass concentration of hydrogen peroxide, and 1.0 g of titanium silicon molecular sieve TS-1 catalyst were added to a batch reactor. After the addition, the mixture was water-oil two-phase, and after stirring, the mixture was turbid liquid. The mixture was heated to 50° C. under stirring, and the reaction time was 2 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 45.2%, the utilization rate of hydrogen peroxide was 52%, and the selectivity of epichlorohydrin was 89.2%.

[0073] Embodiment 13

[0074] 20g of propylene chloride, 3g of 30% mass concentration of hydrogen peroxide, 1g of titanium silicon molecular sieve TS-1 catalyst, 2g of cetyl alcohol phosphate, and 5g of polyethylene glycol 200 were added to a batch reactor and heated to 60°C under stirring, and the reaction time was 2 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 97.5%, the utilization rate of hydrogen peroxide was 98%, and the selectivity of epichlorohydrin was 96.2%.

[0075] Comparative Example 2

[0076] The same reaction conditions as in Example 13 were adopted, but no ionic surfactant and polyol were added in the reaction, and methanol was added as an organic phase. The specific operation was as follows: 20 g of propylene chloride, 3 g of 30% mass concentration of hydrogen peroxide, 1 g of titanium silicon molecular sieve TS-1 catalyst, and 50 g of methanol were added to a batch reactor, and the temperature was raised to 60° C. under stirring, and the reaction time was 2 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, and the results showed that the conversion rate of hydrogen peroxide was 85.3%, the utilization rate of hydrogen peroxide was 89%, and the selectivity of epichlorohydrin was 92.3%.

[0077] 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 preparing epichlorohydrin, characterized in that: At least the following steps are included: A mixture containing allyl chloride, hydrogen peroxide, polyol, catalyst and ionic surfactant is reacted in a batch reactor to obtain a product containing epichlorohydrin; The catalyst contains 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, and 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; The cationic surfactant is selected from at least one of an amine salt type cationic surfactant and a heterocyclic type cationic surfactant; 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 morpholine ring, pyridine ring, imidazole ring, piperazine ring and quinoline ring heterocyclic cationic surfactants; The zwitterionic surfactant is selected from at least one of lecithin-type, amino acid-type and betaine-type zwitterionic surfactants.

3. The method according to claim 1, characterized in that The amine salt type cationic surfactant is selected from at least one of quaternary ammonium salt type cationic surfactants, primary amine salt type cationic surfactants, secondary amine salt type cationic surfactants, and tertiary amine salt type cationic surfactants.

4. The method according to claim 1, characterized in that: 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.

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

1.

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

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

1.

8. The method according to claim 1, characterized in that The mass of the catalyst is 0.1-10 wt % of the mass of allyl chloride.

9. The method according to claim 1, characterized in that: The reaction temperature is 20-90°C.

10. The method according to claim 1, characterized in that The reaction time is 1 to 10 hours.

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