Epoxy chloropropane and preparation method thereof

Abstract

The invention discloses epichlorohydrin and a preparation method thereof. Comprising the following step: reacting a mixed solution containing chloropropene, hydrogen peroxide and an ionic surfactant with a titanium silicalite molecular sieve TS-1 catalyst in a continuous reactor at the liquid phase flow velocity of 0.1-20L / min and the reaction temperature of 20-90 DEG C to obtain the epichlorohydrin. The ionic surfactant is selected from at least one of an anionic surfactant, a cationic surfactant and a zwitterionic surfactant; the molar ratio of the hydrogen peroxide to the ionic surfactant is (1-50): 1; the molar ratio of chloropropene to hydrogen peroxide is (1-10): 1. The ionic surfactant is added to promote mixing of the organic phase and the water phase, a large amount of solvent does not need to be added in a traditional process, a large amount of energy consumption such as solvent evaporation and recovery is avoided, and continuous operation is achieved; the conversion rate of hydrogen peroxide is greater than 95%, and the selectivity of epoxy chloropropane is 95-99%.

Description

Technical Field

[0001] The present application relates to the field of chemical technology, and in particular to epichlorohydrin and a preparation method thereof. Background Art

[0002] Epichlorohydrin is an important organic chemical raw material and fine chemical product with a wide range of applications. Epoxy resins produced from it exhibit strong adhesion, chemical resistance, low shrinkage, excellent chemical stability, high impact strength, and superior dielectric properties. They are widely used in coatings, adhesives, reinforcement materials, casting materials, and electronic laminates. Since the beginning of the 21st century, the application areas of epoxy resins have continued to expand, and production has increased rapidly. my country is currently the world's largest epoxy resin production base, and demand for epichlorohydrin is expected to continue to grow.

[0003] Currently, the three main industrial production methods for ECH worldwide are the propylene high-temperature chlorination method, the propylene acetate method, and the glycerin method. The propylene high-temperature chlorination method is currently the most prevalent production method both domestically and internationally, while the glycerin method is expected to become the future development direction of ECH technology due to its economic and environmental advantages. However, this method is affected by the price of glycerin, resulting in significant market price fluctuations.

[0004] The new process for producing epichlorohydrin using direct oxidation with hydrogen peroxide is an emerging technology and the most environmentally friendly production process for epichlorohydrin to date. This new green process is poised to lead the future development of epichlorohydrin. However, current processes typically use a large amount of solvent to dissolve the raw material allyl chloride and the oxidant hydrogen peroxide into a homogeneous phase. If the solvent is too low, the two phases cannot be fully dissolved, which impedes mass and heat transfer, increases the occurrence of side reactions, and reduces the yield and selectivity of epichlorohydrin. However, the use of solvents not only increases production costs but also requires significant energy to evaporate and recycle the solvent, thus hindering the industrialization of this process. Summary of the Invention

[0005] In view of this, the present application provides epichlorohydrin and a preparation method thereof, the main purpose of which is to solve the technical problems that a large amount of solvent exists in the epichlorohydrin raw material and needs to be evaporated and recovered, resulting in high energy consumption, high cost, and difficulty in achieving continuous production.

[0006] In one aspect, the present application provides a method for preparing epichlorohydrin, comprising the following steps:

[0007] A mixed solution containing allyl chloride, hydrogen peroxide and an ionic surfactant and a titanium silicate TS-1 catalyst are reacted in a continuous reactor to obtain the epichlorohydrin.

[0008] The present application adds an ionic surfactant to the reaction system to form a homogeneous phase between chloropropylene and hydrogen peroxide, which are oil-water phases, and pumps them into a continuous bed reactor equipped with titanium silicate molecular sieve TS-1 through a metering pump to obtain epichlorohydrin. This method promotes the mixing of the organic phase and the aqueous phase by adding an ionic surfactant, eliminates the need for a large amount of solvent added in traditional processes, 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 epichlorohydrin yield and selectivity, and is suitable for industrial large-scale production of epichlorohydrin. At the same time, the method uses multiple metering pumps to achieve continuous production and simple operation. The solvent-free synthesis system used in this method has great economic benefits, low system cost, low environmental pollution, simple operation, easy repeatability, low equipment maintenance cost, and can efficiently produce epichlorohydrin.

[0009] In this application, a continuous reaction form is proposed, and the continuous reactor has the following advantages: the continuous reactor can realize a continuous production process, does not require pauses and loading and unloading operations, and improves production efficiency. Due to the continuous flow of the reaction materials, the continuous reactor effectively utilizes time and space, improves mass transfer and reaction efficiency. The continuous reactor can adjust the parameters such as feed flow rate, temperature, and pressure to precisely control the reaction conditions, thereby obtaining more consistent and accurate products. The continuous reactor can be scaled up relatively easily to adapt to different production volume requirements while maintaining high production efficiency. The continuous reactor usually has better thermal management, can better control and handle dangerous reactions, and reduce the risk of accidents. Therefore, the continuous reactor has important advantages in many industrial applications, and is particularly suitable for efficient, continuous and stable production.

[0010] Ionic surfactants are classified into anionic surfactants (such as sulfates and sulfonates), cationic surfactants (such as quaternary ammonium salts), and zwitterionic surfactants. Ionic surfactants dissociate into ions in aqueous solution, one of which is hydrophilic and the other lipophilic. They exhibit high surface activity, effectively reducing liquid surface tension and improving wettability. They are suitable for forming stable emulsions and dispersions. However, some ionic surfactants are not readily biodegradable, posing potential environmental hazards.

[0011] Optionally, the anionic surfactant is selected from at least one of stearic acid and sodium dodecylbenzenesulfonate.

[0012] Optionally, the cationic surfactant is selected from at least one of quaternary ammonium salt, primary amine salt, secondary amine salt and tertiary amine salt cationic surfactants.

[0013] Optionally, the cationic surfactant is selected from at least one of nitrogen-containing heterocyclic cationic surfactants such as morpholine ring, pyridine ring, imidazole ring, piperazine ring and quinoline ring.

[0014] Optionally, the zwitterionic surfactant is selected from at least one of lecithin-type, amino acid-type, and betaine-type zwitterionic surfactants.

[0015] Optionally, the molar ratio of the hydrogen peroxide solution to the ionic surfactant is 1 to 50:1.

[0016] Optionally, the molar ratio of the hydrogen peroxide to the ionic surfactant is 10 to 50:1;

[0017] Optionally, the molar ratio of the hydrogen peroxide to the ionic surfactant is 30 to 50:1.

[0018] Optionally, the molar ratio of the hydrogen peroxide to the ionic surfactant is selected from any value among 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, or a range between any two of them.

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

[0020] Optionally, the molar ratio of the allyl chloride to the hydrogen peroxide is 3 to 10:1;

[0021] Optionally, the molar ratio of the allyl chloride to the hydrogen peroxide is 5 to 10:1.

[0022] Optionally, the molar ratio of the allyl chloride to the hydrogen peroxide is selected from any value among 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or any range between two values.

[0023] Optionally, the addition amount of the titanium silicate molecular sieve TS-1 catalyst is 0.1 wt% to 10 wt% of the added mass of allyl chloride.

[0024] Optionally, the added amount of the titanium silicate molecular sieve TS-1 catalyst is 1% to 10% of the added mass of allyl chloride.

[0025] Optionally, the added amount of the titanium silicate molecular sieve TS-1 catalyst is 5% to 10% of the added mass of allyl chloride.

[0026] Optionally, the addition amount of the titanium silicate molecular sieve TS-1 catalyst is 0.1%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, or 10% of the added mass of propylene chloride.

[0027] Optionally, the reaction conditions include: a liquid phase flow rate of 0.1 L / min to 20 L / min, a reaction temperature of 20 to 90° C., and a reaction time of 1 to 10 hours.

[0028] Optionally, the liquid phase flow rate is selected from any value among 0.1 L / min, 0.2 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.

[0029] Optionally, the reaction temperature is 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 or 90°C or any value therebetween.

[0030] Optionally, the reaction time is 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.

[0031] Optionally, the titanium silicate molecular sieve TS-1 is selected from titanium-doped silicon-based zeolite molecular sieve materials having an MFI type topology.

[0032] Optionally, the mass concentration of the hydrogen peroxide is 10% to 70%.

[0033] 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.

[0034] Optionally, after the reaction is completed, a certain amount of the reaction liquid is taken to test the epichlorohydrin selectivity and the conversion rate and utilization rate of hydrogen peroxide.

[0035] Optionally, the detection methods used are gas chromatography and hydrogen peroxide liquid phase titration.

[0036] Optionally, the conversion rate of hydrogen peroxide during the reaction is greater than 95%.

[0037] Optionally, the utilization rate of hydrogen peroxide during the reaction is greater than 95%.

[0038] Optionally, the selectivity of epichlorohydrin during the reaction is between 95% and 99%.

[0039] As a specific implementation, the method includes:

[0040] By introducing an ionic surfactant into the reaction system, allyl chloride and hydrogen peroxide (oil-water two phases) form a homogeneous phase, and are pumped into a continuous reactor equipped with titanium silicalite TS-1 through multiple metering pumps according to a certain molar ratio, thereby achieving continuous operation. Allyl chloride is directly epoxidized to prepare epichlorohydrin. Under the conditions of a liquid phase flow rate of 0.1 L / min to 20 L / min, the reaction is carried out for 1 to 10 hours and the reaction temperature is 20 to 90°C to obtain the epichlorohydrin.

[0041] In a second aspect, the present application provides epichlorohydrin, which is prepared using the above-mentioned preparation method.

[0042] The beneficial effects of this application include:

[0043] 1) Compared with traditional methods, the preparation method of epichlorohydrin provided in this application adopts continuous operation during the preparation process, and multiple materials are directly pumped into a continuous reactor through a metering pump to achieve continuous production; titanium silicon molecular sieve TS-1 is used as a catalyst, and hydrogen peroxide is used as an oxygen source to directly oxidize allyl chloride to epichlorohydrin. The reaction has fewer 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.

[0044] 2) Compared with traditional methods, the preparation method of epichlorohydrin provided in the present application can effectively avoid the use of solvents by adding ionic surfactants, thereby improving the reaction conversion rate. The reaction liquid after the reaction is clear and transparent, has a high conversion rate and selectivity, is environmentally friendly, and has low economic costs. It does not require the traditional energy-intensive solvent evaporation and recovery process, improves the selectivity of the reaction, is conducive to industrial production scale-up, has low equipment maintenance costs, and can efficiently produce epichlorohydrin. DETAILED DESCRIPTION

[0045] The present application will be further described below in conjunction with specific embodiments. The following description is merely a few embodiments of the present application and does not limit the present application in any form. Although the present application discloses the preferred embodiments below, it is not intended to limit the present application. Any person skilled in the art who, without departing from the scope of the technical solution of the present application, makes slight changes or modifications using the above disclosed technical content is equivalent to an equivalent implementation case and falls within the scope of the technical solution.

[0046] Unless otherwise specified, the raw materials in the examples of this application were purchased through commercial channels.

[0047] The analysis method in the examples of this application is as follows:

[0048] 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.

[0049] The conversion rate of hydrogen peroxide was detected by cerium sulfate titration method with o-phenanthroline ferrous as the indicator. The titration endpoint was when the light red solution turned into transparent light blue.

[0050] According to one embodiment of the present application, the preparation method of epichlorohydrin comprises the following steps:

[0051] An ionic surfactant is added to the reaction system to form a homogeneous phase between the oil-water phases of allyl chloride and hydrogen peroxide. The phases are then pumped into a continuous reactor containing titanium silicalite TS-1 via a metering pump. The allyl chloride is directly epoxidized to prepare epichlorohydrin. The epichlorohydrin is obtained at a liquid phase flow rate of 0.1 L / min to 20 L / min and a reaction temperature of 20°C to 90°C.

[0052] As a preference of the above embodiment, the mass concentration of hydrogen peroxide is 10% to 70%.

[0053] As preferred in the above embodiment, the ionic surfactant is selected from at least one of anionic surfactants, cationic surfactants or zwitterionic surfactants;

[0054] As a preference in the above embodiment, the anionic surfactant is selected from at least one of stearic acid, sodium dodecylbenzenesulfonate and the like.

[0055] As a preferred embodiment of the above, the cationic surfactant is selected from at least one of amine salt type cationic surfactants such as quaternary ammonium salt type, primary amine salt, secondary amine salt and tertiary amine salt; nitrogen-containing heterocyclic cationic surfactants such as morpholine ring, pyridine ring, imidazole ring, piperazine ring and quinoline ring.

[0056] As a preference of the above embodiment, the amphoteric surfactant is selected from at least one of zwitterionic surfactants such as lecithin-type, amino acid-type, betaine-type and other zwitterionic surfactants.

[0057] As a preference of the above embodiment, titanium silicate molecular sieve TS-1 is a titanium-doped silicon-based zeolite molecular sieve material with an MFI topology.

[0058] As a preferred embodiment of the above embodiment, the molar ratio of allyl chloride to hydrogen peroxide is 1 to 10:1;

[0059] As a preference of the above embodiment, the molar ratio of hydrogen peroxide to the ionic surfactant is 1 to 50:1.

[0060] As a preference of the above embodiment, the added amount of titanium silicate molecular sieve TS-1 catalyst is 0.1% to 10% of the added mass of allyl chloride.

[0061] As a preferred embodiment of the above, the reaction is carried out at a liquid phase flow rate of 0.1 L / min to 20 L / min, for 1 to 10 hours, and at a reaction temperature of 20 to 90°C.

[0062] Example 1

[0063] Using multiple metering pumps, a 45:5:1 molar ratio of allyl chloride: 35% hydrogen peroxide: ionic surfactant sodium dodecylbenzenesulfonate was pumped into a continuous reactor containing titanium silicalite TS-1 catalyst. The reaction was conducted at a flow rate of 3 L / min through a heat exchanger, and the temperature was raised to 45°C. The reaction was continued for 5 hours. After the reaction was completed, a small amount of the reaction liquid was analyzed by gas chromatography and titration with cerium sulfate. The results showed a hydrogen peroxide conversion rate of 97.8%, a hydrogen peroxide utilization rate of 97%, and an epichlorohydrin selectivity of 98.5%.

[0064] Example 2

[0065] Using multiple metering pumps, a molar ratio of 80:10:1 of allyl chloride, 25% hydrogen peroxide, and ionic surfactant sodium stearate was pumped into a continuous reactor containing titanium silicalite TS-1 catalyst. The reaction was conducted at a flow rate of 12 L / min through a heat exchanger, and the temperature was raised to 55°C. The reaction was continued for 1 hour. After the reaction, a small amount of the reaction liquid was analyzed by gas chromatography and titration with cerium sulfate. The results showed a hydrogen peroxide conversion of 97.1%, a hydrogen peroxide utilization of 97%, and an epichlorohydrin selectivity of 96.2%.

[0066] Examples 3 to 11

[0067] The specific ingredients, materials and reaction conditions are shown in Table 1 below. Other operations during the synthesis process are the same as in Example 1.

[0068] Table 1. Raw material composition, ratio, reaction conditions and reaction results of Examples 3 to 11

[0069]

[0070]

[0071] The test results of epichlorohydrin in other examples are similar to those described above, and epichlorohydrin is obtained by the preparation method of the present application.

[0072] Comparative Example 1

[0073] The difference between Comparative Example 1 and Example 12 is that no surfactant is added during the reaction.

[0074] The specific operation was as follows: Allyl chloride and 40% hydrogen peroxide were pumped into a continuous reactor containing a titanium silicalite TS-1 catalyst at a molar ratio of 45:15 using multiple metering pumps. The reaction mixture was passed through a heat exchanger at a flow rate of 20 L / min and heated to 50°C. After the reaction, a small amount of the reaction liquid was analyzed by gas chromatography and titration with cerium sulfate. The results showed a hydrogen peroxide conversion of 70.8%, a hydrogen peroxide utilization of 73%, and an epichlorohydrin selectivity of 82.7%.

[0075] Comparative Example 2

[0076] The difference between Comparative Example 2 and Example 13 is that no ionic surfactant is added during the reaction, but organic phase methanol is added.

[0077] The specific operation was as follows: Allyl chloride: 55% mass concentration hydrogen peroxide: methanol (molar ratio of 36:6:1) was pumped into a continuous reactor containing titanium silicalite TS-1 catalyst using multiple metering pumps. The reaction mixture was passed through a heat exchanger at a flow rate of 10 L / min and heated to 70°C. After the reaction, a small amount of the reaction liquid was analyzed by gas chromatography and titration with cerium sulfate. The results showed a hydrogen peroxide conversion of 85.6%, a hydrogen peroxide utilization of 88%, and an epichlorohydrin selectivity of 89.5%.

[0078] The reaction results of Example 12 and Comparative Example 1 show that the addition of an ionic surfactant to the reaction raw materials in the present application can effectively uniformly mix the organic phase and the aqueous phase into a homogeneous phase, greatly improving the hydrogen peroxide conversion rate, hydrogen peroxide utilization rate, and epichlorohydrin selectivity; at the same time, the addition of an ionic surfactant in the present application can effectively avoid the large-scale use of organic solvents and the subsequent energy-intensive solvent evaporation recovery process in traditional processes. This method has great economic benefits, low system cost, low environmental pollution, simple operation, easy repeatability, low equipment maintenance cost, and can efficiently produce epichlorohydrin.

[0079] The reaction results of Example 13 and Comparative Example 2 show that although methanol additive was added in Comparative Example 2 to improve the conversion rate of hydrogen peroxide, the effect was not optimal. The specific ionic surfactant selected in this application can better mix the organic phase of the reaction, allyl chloride, and the aqueous phase of hydrogen peroxide into a homogeneous phase, which is more conducive to the reaction and is more conducive to improving the reaction efficiency of hydrogen peroxide and allyl chloride and the selectivity of cyclopropylchloropropane.

[0080] The above descriptions are merely a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application discloses the preferred embodiments as above, they are not intended to limit the present application. Any technical personnel familiar with the present 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: The following steps are involved: A mixed solution containing allyl chloride, hydrogen peroxide and an ionic surfactant and a titanium silicate TS-1 catalyst are reacted in a continuous reactor to obtain the epichlorohydrin.

2. The method for preparing epichlorohydrin according to claim 1, wherein: The ionic surfactant is selected from at least one of anionic surfactants, cationic surfactants and zwitterionic surfactants.

3. The method for preparing epichlorohydrin according to claim 2, wherein: The anionic surfactant is selected from at least one of stearic acid and sodium dodecylbenzene sulfonate; Preferably, the zwitterionic surfactant is selected from at least one of lecithin-type, amino acid-type, and betaine-type zwitterionic surfactants.

4. The method for preparing epichlorohydrin according to claim 1, wherein: The cationic surfactant is selected from at least one of quaternary ammonium salt, primary amine salt, secondary amine salt and tertiary amine salt cationic surfactants; And / or, the cationic surfactant is at least one selected from nitrogen-containing heterocyclic cationic surfactants such as morpholine ring, pyridine ring, imidazole ring, piperazine ring and quinoline ring.

5. The method for preparing epichlorohydrin according to claim 1, wherein: The molar ratio of the hydrogen peroxide solution to the ionic surfactant is 1 to 50:

1.

6. The method for preparing epichlorohydrin according to claim 1, wherein: The molar ratio of the allyl chloride to the hydrogen peroxide is 1 to 10:

1.

7. The method for preparing epichlorohydrin according to claim 1, wherein: The reaction conditions include: a liquid phase flow rate of 0.1 L / min to 20 L / min, a reaction temperature of 20 to 90° C., and a reaction time of 1 to 10 hours.

8. The method for preparing epichlorohydrin according to claim 1, wherein: The titanium silicate molecular sieve TS-1 is selected from titanium-doped silica-based zeolite molecular sieve materials with an MFI type topology.

9. The method for preparing epichlorohydrin according to claim 1, wherein: The mass concentration of the hydrogen peroxide is 10% to 70%.

10. Epichlorohydrin, characterized in that The epichlorohydrin is prepared by the method according to any one of claims 1 to 9.

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