Epoxy chloropropane and preparation method thereof

Abstract

The invention discloses epichlorohydrin and a preparation method thereof, and belongs to the technical field of chemical engineering. The method comprises 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 batch kettle reactor at 20-90 DEG C for 1-10 hours to obtain the epichlorohydrin. The dosage of the catalyst is 0.1-10 wt% of the chloropropene; the ionic surfactant is selected from 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, and a large amount of energy consumption such as solvent evaporation and recovery is avoided; 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 (ECH) is an important organic chemical raw material and a key intermediate in the petrochemical industry. It is primarily used in the production of epoxy resins, glycerin, epichlorohydrin rubber, and other derivatives. It can also be used as a solvent, plasticizer, flame retardant, and surfactant. Currently, the main production processes for epichlorohydrin are the glycerin method, the high-temperature chlorination method for propylene (referred to as the propylene method), and the new hydrogen peroxide method. In terms of production capacity share, the glycerin method is the primary method, supplemented by the propylene method, and the hydrogen peroxide method has the lowest overall share.

[0003] 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".

[0004] The glycerol production process has the advantages of mild reaction conditions, high selectivity and yield, low pollution, and consumption of 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 production capacity of epichlorohydrin by the glycerol method in China, 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 method 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 methods, and the demand is in a growing state. The price of glycerol may be difficult to return to the previous low level of three to four thousand, so the gross profit margin of epichlorohydrin by the glycerol method may be at a relatively low level.

[0005] The new hydrogen peroxide process for producing epichlorohydrin 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 and a titanium silicate TS-1 catalyst are reacted in an intermittent reactor to obtain the epichlorohydrin.

[0009] This application uses allyl chloride, hydrogen peroxide, and an ionic surfactant as raw materials, titanium silicalite TS-1 as a catalyst, and uses an intermittent reactor to directly epoxidize allyl chloride to prepare epichlorohydrin. By adding an ionic surfactant to the raw materials, this application promotes mixing of the organic phase (allyl chloride) and the aqueous phase (hydrogen peroxide) of the raw materials, eliminating the need for the large amount of solvent added in traditional processes, thereby avoiding energy-intensive processes such as solvent evaporation and recovery. The process is energy-saving and environmentally friendly, the equipment and process are simple, and 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 the method of this application has great economic benefits, low system cost, low environmental pollution, simple operation, easy repeatability, low equipment maintenance cost, and can efficiently produce epichlorohydrin.

[0010] In this application, a batch reactor is used. The batch reactor has good flexibility. The batch reactor can accurately control the reaction temperature, pressure and stirring speed to meet the requirements of a specific reaction. In addition, the batch reactor usually has a sturdy structure and safety devices, which can effectively control and handle hazardous substances in the reaction. The batch reactor usually has a simple operating interface and an easy-to-clean design, which is convenient for operation and maintenance. The batch reactor can be mass-produced as needed and is suitable for small-scale or medium-scale production. Compared with continuous flow reactors, the equipment and operating costs of batch reactors are lower, and they are suitable for small-scale production and research and development stages.

[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, secondary amine salt and tertiary amine salt type cationic surfactants.

[0015] 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.

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

[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 any value among 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%, 10% of the added mass of propylene chloride, or any range value between two of them.

[0029] Optionally, the titanium silicate molecular sieve TS-1 is selected from titanium-doped silicon-based zeolite molecular sieve materials having an MFI type topology.

[0030] Optionally, the mass concentration of the hydrogen peroxide is 10% to 70%.

[0031] 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.

[0032] Optionally, the reaction temperature is 20 to 90° C., and the reaction time is 1 to 10 hours.

[0033] 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.

[0034] Optionally, the reaction time is selected from any value among 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours or 10 hours, or any value therebetween.

[0035] 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.

[0036] Optionally, the detection methods used are gas chromatography and hydrogen peroxide liquid phase titration.

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

[0038] Optionally, the utilization rate of hydrogen peroxide during the reaction is greater than 95%.

[0039] Optionally, the selectivity of epichlorohydrin during the reaction is between 95% and 99%.

[0040] As a specific implementation, the method includes:

[0041] A mixed solution containing allyl chloride, hydrogen peroxide and an ionic surfactant is added to a batch reactor using titanium silicalite TS-1 as a catalyst, and the reaction temperature is 20-90° C. and the reaction time is 1-10 hours to obtain the epichlorohydrin.

[0042] In a second aspect, the present application provides epichlorohydrin, which is prepared using the above-mentioned preparation method.

[0043] The beneficial effects of this application include:

[0044] 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.

[0045] 2) Compared with traditional methods, the preparation method of epichlorohydrin provided in the present application effectively avoids the use of solvents by adding ionic surfactants, thereby improving the conversion rate of the reaction. 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, greatly reduces equipment maintenance costs and labor costs, and can efficiently produce epichlorohydrin. DETAILED DESCRIPTION

[0046] 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.

[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 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.

[0051] According to one embodiment of the present application, the preparation method of epichlorohydrin comprises the following steps:

[0052] A mixed solution containing allyl chloride, hydrogen peroxide and an ionic surfactant is added to a batch reactor using titanium silicalite TS-1 as a catalyst. The reaction temperature is 20-90° C. and the reaction time is 1-10 hours to obtain epichlorohydrin.

[0053] The present application adopts a batch reactor to prepare epichlorohydrin. The kettle type is an intermittent operation, and the intermittent type is mainly to control the residence time of the material in the reactor.

[0054] As a preference of the above embodiment, the mass concentration of hydrogen peroxide is 10% to 70%.

[0055] As preferred in the above embodiment, the ionic surfactant is selected from at least one of anionic surfactants, cationic surfactants or zwitterionic surfactants.

[0056] As a preference in the above embodiment, the anionic surfactant is selected from at least one of stearic acid and sodium dodecylbenzenesulfonate.

[0057] As a preferred embodiment of the above, the cationic surfactant is selected from at least one of the quaternary ammonium salt type, primary amine salt, secondary amine salt and tertiary amine salt cationic surfactants in the amine salt type, and nitrogen-containing heterocyclic cationic surfactants such as morpholine ring, pyridine ring, imidazole ring, piperazine ring and quinoline ring.

[0058] 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.

[0059] 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.

[0060] As a preferred embodiment of the above embodiment, the molar ratio of allyl chloride to hydrogen peroxide is 1 to 10:1;

[0061] As a preference of the above embodiment, the molar ratio of hydrogen peroxide to the ionic surfactant is 1 to 50:1.

[0062] 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.

[0063] As a preference of the above embodiment, the reaction conditions include: reaction temperature of 20° C. to 90° C., and reaction time of 1 to 10 hours.

[0064] Example 1

[0065] A batch reactor was charged with 5g of allyl chloride, 2g of 35% mass concentration hydrogen peroxide, 0.5g of titanium silicalite TS-1 catalyst, and 0.5g of sodium dodecylbenzenesulfonate. The mixture was heated to 45°C with stirring and reacted 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 98.2%, a hydrogen peroxide utilization of 97%, and an epichlorohydrin selectivity of 97.5%.

[0066] Example 2

[0067] A batch reactor was charged with 25g of allyl chloride, 5g of 55% mass concentration hydrogen peroxide, 2g of titanium silicalite TS-1 catalyst, and 3.5g of potassium cetyl phosphate. The mixture was heated to 65°C with stirring and allowed to react for 5 hours. 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 98.6%, a hydrogen peroxide utilization of 97%, and an epichlorohydrin selectivity of 99.0%.

[0068] Examples 3 to 11

[0069] 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.

[0070] Table 1. Raw material composition, ratio, reaction conditions and reaction results of Examples 3 to 11

[0071]

[0072]

[0073] 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.

[0074] Comparative Example 1

[0075] The difference between Comparative Example 1 and Example 12 is that no surfactant is added during the reaction.

[0076] The specific operation is as follows: 23g of allyl chloride, 7.5g of 15% mass concentration hydrogen peroxide, and 1.5g of titanium silicate TS-1 catalyst were added to a batch reactor. After addition, a water-oil two-phase reaction was formed, which became a turbid liquid after stirring. The reaction was heated to 55°C while stirring, and the reaction was carried out for 3 hours. 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 68.1%, a hydrogen peroxide utilization of 68%, and an epichlorohydrin selectivity of 92.1%.

[0077] Comparative Example 2

[0078] 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.

[0079] The specific operation was as follows: 16g of allyl chloride, 5g of 35% mass concentration hydrogen peroxide, 1g of titanium silicate TS-1 catalyst, and 50g of methanol were added to a batch reactor. The temperature was raised to 45°C while stirring, and the reaction was carried out for 2 hours. 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 86.5%, a hydrogen peroxide utilization of 93%, and an epichlorohydrin selectivity of 93.1%.

[0080] 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.

[0081] 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 the present 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.

[0082] 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 an intermittent 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 1, wherein: The anionic surfactant is selected from at least one of stearic acid and sodium dodecylbenzene sulfonate; Preferably, 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; Preferably, 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; 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 molar ratio of the hydrogen peroxide solution to the ionic surfactant is 1 to 50:

1.

5. 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.

6. The method for preparing epichlorohydrin according to claim 1, wherein: The addition amount of the titanium silicate molecular sieve TS-1 catalyst is 0.1 wt% to 10 wt% of the amount of allyl chloride used.

7. 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.

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

9. The method for preparing epichlorohydrin according to claim 1, wherein: The reaction temperature is 20 to 90° C., and the reaction time is 1 to 10 hours.

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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