Epoxy chloropropane and preparation method thereof
By using a fixed-bed reactor with an ionic surfactant and titanium silicate TS-1 catalyst in the production of epichlorohydrin, the problem of high energy consumption in solvent evaporation and recovery is solved, and efficient, low-cost and environmentally friendly epichlorohydrin preparation is achieved.
Patent Information
- Application Number
- CN202410302168.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-15
- Publication Date
- 2025-09-16
AI Technical Summary
The solvent needs to be evaporated and recovered in the production of epichlorohydrin, which leads to high energy consumption and high cost.
A mixed solution containing allyl chloride, hydrogen peroxide and ionic surfactant is reacted in a fixed bed reactor with titanium silicalite TS-1 catalyst, avoiding the use of traditional solvents. The ionic surfactant is used to promote the formation of a homogeneous phase between the oil and water phases, and epichlorohydrin is directly oxidized to prepare it.
It improves the reaction conversion rate and selectivity, reduces production costs, reduces environmental pollution, is suitable for large-scale industrial production, and has low equipment maintenance costs.
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Abstract
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 (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 high-temperature chlorination method of propylene (referred to as the propylene method), and the new hydrogen peroxide method. In terms of production capacity share, the glycerol method is the main one, the propylene method is the auxiliary one, and the hydrogen peroxide method has the lowest overall share. 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. However, with the continuous release of new production capacity of epichlorohydrin by the glycerol method in China, the demand for glycerol has continued to increase, thereby supporting the glycerol market trend. In 2021, the price of 99.5% glycerol content once climbed to a high level of 14,000 yuan / ton, resulting in a sharp increase in the cost of the glycerol method. Glycerol-based epichlorohydrin is in a high-cost and low-profit state, and even in a loss-making state in some stages.
[0004] Although the high-temperature chlorination method of propylene to produce epichlorohydrin is a mature process, 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 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
[0006] In view of this, the present application provides epichlorohydrin and a preparation method thereof, the main purpose of which is to solve the technical problem that a large amount of solvent exists in the epichlorohydrin raw material and needs to be evaporated and recovered, resulting in high energy consumption and high cost.
[0007] In one aspect, the present application provides a method for preparing epichlorohydrin, comprising the following steps:
[0008] A mixed solution containing allyl chloride, hydrogen peroxide and an ionic surfactant reacts with a titanium silicate TS-1 catalyst in a fixed bed reactor to obtain the epichlorohydrin.
[0009] This application adds an ionic surfactant to the reaction system to form a homogeneous phase between the oil-water phases of allyl chloride and hydrogen peroxide. This phase is then pumped into a fixed-bed reactor containing titanium silicalite TS-1 via a metering pump to produce epichlorohydrin. This method promotes mixing of the organic and aqueous phases by adding an ionic surfactant, eliminating the need for the large amounts of solvents added in traditional processes and avoiding energy-intensive processes such as solvent evaporation and recovery. The process is energy-efficient and environmentally friendly, with simple equipment and process steps. The yield and selectivity of epichlorohydrin are high, making it suitable for large-scale industrial production of epichlorohydrin. The solvent-free synthesis system used in this method offers significant economic benefits, low system costs, minimal environmental impact, simple and repeatable operation, and low equipment maintenance costs, enabling efficient production of epichlorohydrin.
[0010] In the present application, the advantages of using a fixed bed reactor include the following: the fixed bed reactor has a large reaction surface area, which can achieve high catalytic activity and reaction efficiency. At the same time, the fixed bed reactor can stably maintain the reaction temperature and pressure, reducing the impact of temperature and pressure fluctuations on the reaction. The fixed bed reactor is suitable for continuous production, can achieve a continuous reaction process, and improve production efficiency. The fixed bed reactor can control the reaction rate and product selectivity by adjusting the feed flow rate and reactant concentration. The fixed bed reactor generally has lower equipment and operating costs and is suitable for large-scale production and industrial applications.
[0011] 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.
[0012] Optionally, the ionic surfactant is selected from at least one of anionic surfactants, cationic surfactants, and zwitterionic surfactants.
[0013] Optionally, the anionic surfactant is selected from at least one of stearic acid and sodium dodecylbenzenesulfonate.
[0014] Optionally, the cationic surfactant is selected from at least one of quaternary ammonium salt type, primary amine salt type, secondary amine salt type and tertiary amine salt type cationic surfactants.
[0015] Optionally, the cationic surfactant is selected from at least one of nitrogen-containing heterocyclic cationic surfactants including morpholine ring, pyridine ring, imidazole ring, piperazine ring and quinoline ring.
[0016] Optionally, the zwitterionic surfactant is selected from at least one of lecithin type, amino acid type, and betaine type.
[0017] Optionally, the molar ratio of the hydrogen peroxide solution to the ionic surfactant is 1 to 50:1.
[0018] Optionally, the molar ratio of the hydrogen peroxide to the ionic surfactant is 10 to 50:1;
[0019] Optionally, the molar ratio of the hydrogen peroxide to the ionic surfactant is 30 to 50:1.
[0020] 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.
[0021] Optionally, the molar ratio of the allyl chloride to the hydrogen peroxide is 1 to 10:1.
[0022] Optionally, the molar ratio of the allyl chloride to the hydrogen peroxide is 3 to 10:1.
[0023] Optionally, the molar ratio of the allyl chloride to the hydrogen peroxide is 5 to 10:1.
[0024] 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.
[0025] 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.
[0026] Optionally, the added amount of the titanium silicate molecular sieve TS-1 catalyst is 1% to 10% of the added mass of allyl chloride.
[0027] Optionally, the added amount of the titanium silicate molecular sieve TS-1 catalyst is 5% to 10% of the added mass of allyl chloride.
[0028] 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.
[0029] Optionally, the feed mass space velocity is 0.5 to 10 h -1 .
[0030] Optionally, the feed mass space velocity is 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.
[0031] Optionally, the reaction temperature is 20 to 90° C., and the reaction time is 1 to 10 hours.
[0032] 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.
[0033] Optionally, the titanium silicate molecular sieve TS-1 is selected from titanium-doped silicon-based zeolite molecular sieve materials having an MFI type topology.
[0034] Optionally, the mass concentration of the hydrogen peroxide is 10% to 70%.
[0035] 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.
[0036] 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.
[0037] Optionally, the detection methods used are gas chromatography and hydrogen peroxide liquid phase titration.
[0038] Optionally, the conversion rate of hydrogen peroxide during the reaction is greater than 95%.
[0039] Optionally, the utilization rate of hydrogen peroxide during the reaction is greater than 95%.
[0040] Optionally, the selectivity of epichlorohydrin during the reaction is between 95% and 99%.
[0041] As a specific implementation, the method includes:
[0042] An ionic surfactant is added to the reaction system to make the oil-water phase of allyl chloride and hydrogen peroxide form a homogeneous phase, which is then pumped into a fixed-bed reactor filled with titanium silicate molecular sieve TS-1 through a metering pump to directly epoxidize allyl chloride to produce epichlorohydrin. The feed mass space velocity is 0.5 to 10 h -1 The reaction temperature is between 20°C and 90°C to obtain the epichlorohydrin.
[0043] In a second aspect, the present application provides epichlorohydrin, which is prepared using the above-mentioned preparation method.
[0044] The beneficial effects of this application include:
[0045] 1) Compared with the traditional method, the preparation method of epichlorohydrin provided in the present application uses titanium silicalite TS-1 as a catalyst and hydrogen peroxide 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.
[0046] 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
[0047] 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.
[0048] Unless otherwise specified, the raw materials in the examples of this application were purchased through commercial channels.
[0049] The analysis method in the examples of this application is as follows:
[0050] 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.
[0051] 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.
[0052] According to one embodiment of the present application, the preparation method of epichlorohydrin comprises the following steps:
[0053] An ionic surfactant is added to the reaction system to make the oil-water phase of allyl chloride and hydrogen peroxide form a homogeneous phase, which is then pumped into a fixed-bed reactor filled with titanium silicate molecular sieve TS-1 through a metering pump to directly epoxidize allyl chloride to produce epichlorohydrin. The feed mass space velocity is 0.5 to 10 h -1 The reaction temperature is between 20°C and 90°C to obtain the epichlorohydrin.
[0054] The present application uses a fixed bed reactor to achieve continuous production, which requires controlling the reaction space velocity.
[0055] As a preference of the above embodiment, the mass concentration of hydrogen peroxide is 10% to 70%.
[0056] As a preference in the above embodiment, the ionic surfactant is selected from at least one of anionic surfactants, cationic surfactants or zwitterionic surfactants.
[0057] As a preference in the above embodiment, the anionic surfactant is selected from at least one of stearic acid and sodium dodecylbenzenesulfonate.
[0058] As a preferred embodiment of the above, the 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 in the amine salt type; nitrogen-containing morpholine ring, pyridine ring, imidazole ring, piperazine ring and quinoline ring heterocyclic cationic surfactants.
[0059] As a preference in the above embodiment, the amphoteric surfactant is selected from at least one of lecithin-type, amino acid-type, and betaine-type zwitterionic surfactants.
[0060] 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.
[0061] As a preferred embodiment of the above embodiment, the molar ratio of allyl chloride to hydrogen peroxide is 1 to 10:1;
[0062] As a preference of the above embodiment, the molar ratio of hydrogen peroxide to the ionic surfactant is 1 to 50:1.
[0063] 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.
[0064] As the preferred embodiment of the above, the reaction conditions include: the feed mass space velocity is 0.5~10h -1 , the reaction temperature is 20°C to 90°C, and the reaction time is 1 to 10 hours.
[0065] Example 1
[0066] Use a metering pump at an air velocity of 3.5h -1 A mixed solution of allyl chloride, 25% mass concentration hydrogen peroxide, and sodium dodecylbenzenesulfonate was pumped into a fixed-bed reactor containing a titanium silicalite TS-1 catalyst at a molar ratio of allyl chloride:hydrogen peroxide:ionic surfactant of 50:6:1. The temperature was raised to 40°C. After the reaction, a small amount of the reaction liquid was analyzed by gas chromatography and hydrogen peroxide titration with cerium sulfate. The results showed that the hydrogen peroxide conversion rate was 98.4%, the hydrogen peroxide utilization rate was 97%, and the epichlorohydrin selectivity was 98.7%.
[0067] Example 2
[0068] Use a metering pump at an air velocity of 2.5h -1 A mixed solution of allyl chloride, 35% mass concentration hydrogen peroxide, and sodium stearate was pumped into a fixed-bed reactor containing a titanium silicalite TS-1 catalyst at a molar ratio of allyl chloride: hydrogen peroxide: ionic surfactant of 100:8:1. The temperature was then raised to 65°C. After the reaction, a small amount of the reaction liquid was analyzed by gas chromatography and titration with cerium sulfate using hydrogen peroxide. The results showed a hydrogen peroxide conversion of 97.7%, a hydrogen peroxide utilization of 97%, and an epichlorohydrin selectivity of 98.4%.
[0069] Examples 3 to 11
[0070] 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.
[0071] Table 1. Raw material composition, ratio, reaction conditions and reaction results of Examples 3 to 11
[0072]
[0073]
[0074] 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.
[0075] Comparative Example 1
[0076] The difference between Comparative Example 1 and Example 12 is that no surfactant is added during the reaction.
[0077] The specific operation is as follows: Use a metering pump at an air speed of 3.5h -1 A mixed solution of allyl chloride and 35% hydrogen peroxide (wt%) was pumped into a fixed-bed reactor containing a titanium silicalite TS-1 catalyst at a molar ratio of 45:5. The mixture was heated to 40°C, resulting in a water-oil two-phase system. After stirring, a turbid liquid formed. After the reaction, a small amount of the reaction liquid was analyzed by gas chromatography and titration with hydrogen peroxide using cerium sulfate. The results showed a hydrogen peroxide conversion of 83.5%, a hydrogen peroxide utilization of 68%, and an epichlorohydrin selectivity of 90.3%.
[0078] Comparative Example 2
[0079] 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.
[0080] The specific operation is as follows: Use a metering pump at an air speed of 8.5h -1 A mixed solution of allyl chloride, 40% hydrogen peroxide, and methanol was pumped into a fixed-bed reactor containing a titanium silicalite TS-1 catalyst at a molar ratio of allyl chloride: hydrogen peroxide: methanol of 10:4:1. The temperature was then raised to 50°C. After the reaction, a small amount of the reaction liquid was analyzed by gas chromatography and titration with cerium sulfate for hydrogen peroxide. The results showed a hydrogen peroxide conversion of 90.6%, a hydrogen peroxide utilization of 91%, and an epichlorohydrin selectivity of 93.2%.
[0081] 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.
[0082] 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.
[0083] 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 reacts with a titanium silicate TS-1 catalyst in a fixed bed 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.
4. The method for preparing epichlorohydrin according to claim 2, wherein: 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; And / or, the cationic surfactant is selected from at least one of quaternary ammonium salt type, primary amine salt type, secondary amine salt type and tertiary amine salt type cationic surfactants.
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: feed mass space velocity of 0.5 to 10 h -1 , the reaction temperature is 20-90℃.
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.