WO2019196681A1 - Process for preparing epichlorohydrin by means of direct epoxidation of chloropropene, modified heteropolyacid immobilized catalyst and preparation method therefor - Google Patents

Abstract

Disclosed in the present invention is a process for preparing epichlorohydrin by means of the direct epoxidation of chloropropene, a modified heteropolyacid immobilized catalyst and a preparation method therefor; specifically, disclosed is a process route for preparing epichlorohydrin by means of the direct epoxidation of chloropropene in the presence of a modified heteropolyacid immobilized catalyst by using hydrogen peroxide as an oxygen source. The main advantages of the process are: ① the ratio of chloropropene to hydrogen peroxide is low, and the amount of chloropropene is small; ② reaction and separation processes are coupled to save equipment, and the process is simple; ③ a side reaction of hydrolysis between epichlorohydrin and water under acidic conditions is prevented, and the yield and selectivity of epichlorohydrin are high.

Description

Process for preparing epichlorohydrin by direct epoxidation of chloropropene, modified heteropoly acid immobilization catalyst and preparation method thereof Technical field

The invention relates to a process for preparing epichlorohydrin by direct epoxidation of chloropropene, a modified heteropolyacid catalyzed catalyst and a preparation method thereof, and more particularly to a modified heteropolyacid solid of chloropropene. The process route for preparing epichlorohydrin by direct epoxidation using hydrogen peroxide as oxygen source in the presence of a supported catalyst.

Background technique

Epichlorohydrin is an important petrochemical product used primarily in the production of epoxy resins and synthetic glycerin. At present, the industrial synthesis methods of epichlorohydrin mainly include acrylic acid propylene ester method, propylene method and glycerin method, and the propylene method is further divided into a chlorohydrin method and a direct epoxidation method. The propylene acetate method, the glycerol method and the chlorohydrin method are both dichloropropanol and then saponified and cyclized to form epichlorohydrin. Both processes bring a large amount of wastewater containing calcium chloride, and more and more Not suitable for the development of green chemistry. In order to solve the problem of a large amount of salty wastewater, scientists have studied the direct epoxidation of chloropropene to produce epichlorohydrin. The commonly used catalysts are mainly titanium silicalite and heteropolyacid salts.

CN1769277A discloses a process for producing epichlorohydrin, which uses titanium silicalite as a catalyst to continuously add liquid phase or gas phase chloropropene and hydrogen peroxide to a special spiral channel type rotary bed or rotary packed bed supergravity reactor. The epichlorohydrin is prepared by directly performing an epoxidation reaction.

In 1985, Carlo Venturello et al. proposed a preparation method of [PW ₄ O ₂₄ ] ^3- type quaternary ammonium phosphotungstic heteropoly acid catalyst. In 1988, it was first reported that hydrogen peroxide was used as the oxygen source and the phosphotungstic heteropoly acid. Direct epoxidation of chloropropene to prepare epichlorohydrin. During the reaction, [R ₄ N ⁺ ] ₃ {PO ₄ [WO(O ₂ ) ₂ ] ⁴ } ^3- is a catalytically active species, benzene is The solvent was reacted for 2.5 h, and the yield of epichlorohydrin was 85%. In 1988, Japanese Yasutaka Ishii studied in detail the application of different quaternary ammonium salt modified phosphotungstic heteropolyacid catalysts in the double bond epoxidation of catalysts, and proposed the reaction mechanism, ie before the reaction, on J. Org. Chem. The catalyst is an insoluble solid, and the reaction is dissolved in the reaction system by the action of hydrogen peroxide to carry out a homogeneous catalytic reaction; when the hydrogen peroxide is exhausted, the catalyst can be precipitated from the reaction system, and can be recycled by separation. Chinese patents CN101205219, CN101045717 and CN100532371 after 2000 have provided a process for the preparation of epichlorohydrin by epoxidation of chloropropene with quaternary ammonium phosphotungstate as catalyst, hydrogen peroxide as oxygen source, and hydrogen peroxide concentration. The solvent type and the type of additives overcome the adverse effects of the presence of the aqueous phase on the epoxidation reaction.

In the past 30 years from 1988 to the present, there have been many literatures and patents on the study of transition metal heteropolyacids, but there are basically no examples of industrialization in the public reports. The following deficiencies in the preparation of epichlorohydrin by chloropropylene epoxidation include: 1 The process of preparing epichlorohydrin using titanium silicalite as a catalyst, most of which require the use of methanol, methanol on the one hand as a solvent, on the other hand activation Catalyst; and the catalyst needs to be regenerated frequently; 2 The process of preparing epichlorohydrin by using phosphotungstic heteropoly acid as catalyst, the molar ratio of chloropropene to hydrogen peroxide is 4:1 or more, and the amount is larger; 3 Propane is easily hydrolyzed in the aqueous phase under acidic conditions, and the yield and selectivity of epichlorohydrin are not high.

Heteropolyacids are composed of heteroatoms (such as P, Si, Fe, Co, etc.) and polyatoms (such as Mo, W, V, Nb, Ta, etc.) which are bridged by oxygen atoms in a certain structure. Oxygen acid. It is not only acidic, but also redox, it is a multifunctional new catalyst; it can be used to catalyze reactions such as homogeneous, heterogeneous and phase transfer. These catalysts have good stability and no pollution to the environment, and are a promising green catalyst. The existing heteropoly acid preparation methods mainly include an ether acid extraction method and an ion exchange method. The acidification extraction process requires more stringent requirements, and the acidification pH is very high. Even if the difference is 0.01, the structure of the product is completely different. At the same time, the ether is characterized by low boiling point, toxic, flammable and extremely volatile, and the use process is dangerous. polluted environment. The ion exchange method avoids the use of diethyl ether and has high production safety, but the production cycle is long, the energy consumption is extremely large, and the production capacity is limited, which becomes a bottleneck of industrial production.

CN102744088A discloses a preparation method of phosphotungstic heteropoly acid: dissolving sodium tungstate and disodium hydrogen phosphate in water, producing a mixed solution of phosphotungstic acid and sodium phosphotungstate under heating and acidic conditions, and then C _n H The organic solution of _2n+1 N ⁺ Cl ^- is added to a mixed solution of phosphotungstic acid and sodium phosphotungstate. After the reaction, the product is centrifuged, washed, dried and calcined to obtain a phosphotungstic heteropoly acid.

CN107282106 discloses a preparation method and application of a weak water-soluble supported phosphotungstic heteropoly acid: dissolving sodium tungstate in water and adding it to dilute hydrochloric acid to obtain a yellow-green solid; adding a yellow-green solid to the phosphoric acid solution a plurality of times, Stirring water-soluble phosphotungstic heteropoly acid; adding citric acid, titanium silicon molecular sieve (TS-1) and potassium chloride solution; centrifuging and drying the precipitate to obtain the supported tungsten-phosphorus heteropoly acid of TS-1. The yield was 79.85%.

Heteropolyacids have good water solubility, poor solubility in organic phase, which makes catalyst recovery difficult, and there is unstable catalytic activity due to uneven distribution in practical application; compared with other acid catalysts, the price is high, Cannot be applied to industrial production. Therefore, research on heteropoly acid immobilization methods and improvement of catalyst recovery rate are of great significance for promoting petrochemical production.

The invention describes a process for preparing epichlorohydrin by direct epoxidation of chloropropene with hydrogen peroxide in a modified heteropolyacid supported catalyst. The main advantages of this process are: 1 low ratio of chloropropene to hydrogen peroxide, less chloropropene; 2 coupling of reaction and separation process, saving equipment, simple process; 3 avoiding hydrolysis of epichlorohydrin under acidic conditions with water The side reaction, the epichlorohydrin yield and selectivity are high.

Summary of the invention

The main object of the present invention is to provide a method for preparing epichlorohydrin by direct epoxidation of chloropropene, a modified heteropolyacid supported catalyst and a preparation method thereof, so as to solve the preparation of epichlorohydrin chloride in the prior art. The problem of more propylene consumption.

One of the technical problems to be solved by the present invention is to provide a method for preparing epichlorohydrin by direct epoxidation of chloropropene in the presence of a catalyst using hydrogen peroxide as an oxygen source, which has a low ratio of chloropropene to hydrogen peroxide, chlorine. The amount of propylene is low; the reaction and the separation process are coupled to avoid the side reaction of epichlorohydrin under acidic conditions, hydrolysis with water, and the high yield and selectivity of epichlorohydrin.

In order to achieve the object of the present invention, the present invention employs the following experimental method: in a reduced pressure system, a metering pump is used to pump chloropropene from the bottom into a fixed bed containing a modified heteropolyacid supported catalyst at a certain space velocity. In the reactor, hydrogen peroxide and chloropropene are pumped from the top into the fixed bed reactor at a certain molar ratio, and reacted at a certain temperature and pressure; while the reaction, the chloropropene, epichlorohydrin and water are stripped from the top of the reactor. The system, monochloropropanediol and another part of water from the bottom of the reactor out of the system; the top reaction liquid oil moisture layer, the oil layer is cooled to determine the composition, the water layer is incorporated into the bottom reaction liquid and then cooled to determine the composition, calculate the hydrogen peroxide conversion rate, epoxy Chloropropane and monochloropropanediol yield, epichlorohydrin selectivity and hydrogen peroxide utilization.

The chloropropene and hydrogen peroxide according to the present invention have a molar ratio of 0.85 to 2.00:1, preferably 0.95 to 1.50:1;

The chloropropene feed mass space velocity of the present invention is 1.5 to 10.0 h ^-1 , preferably 3.0 to 6.0 h ^-1 ;

The reaction temperature according to the present invention is 30 to 90 ° C, preferably 40 to 80 ° C; and the vacuum degree of the reduced pressure system is 5 to 65 kPa, preferably 20 to 60 kPa.

Further, the modified heteropolyacid supported catalyst has the following structural formula I:

Wherein, n is any one of 3 to 20, preferably any one of 7 to 14, and a is an integer of 250 to 300, and b is an integer of 10 to 50, and R ₁ and R ₂ And R ₃ are each independently selected from any one of C ₁ to C ₁₀ hydrocarbon groups, and further preferably each of R ₁ , R ₂ and R _{3 is} independently selected from a C ₁ -C ₄ alkyl group.

In order to achieve the above object, according to another aspect of the present invention, there is provided a process for the direct epoxidation of chloropropene to produce epichlorohydrin, which comprises: catalyzing the reaction of chloropropene and hydrogen peroxide with a modified heteropolyacid supported catalyst; The epoxidation reaction produces epichlorohydrin, wherein the modified heteropolyacid supported catalyst has the following structural formula I:

Wherein n is any one of 3 to 20, a is an integer of 250 to 300, b is an integer of 10 to 50, and R ₁ , R ₂ and R ₃ are each independently selected from C ₁ Any one of -C ₁₀ hydrocarbon groups.

Further, the above n is an integer of any one of 7 to 14, and R ₁ , R ₂ and R ₃ are each independently selected from any one of C ₁ to C ₄ alkyl groups.

Further, the molar ratio of the above chloropropene to hydrogen peroxide is from 0.85 to 2.00:1, preferably from 0.95 to 1.50:1.

Further, the above-mentioned chloropropene feed mass space velocity is 1.5 to 10.0 h ^-1 , preferably 3.0 to 6.0 h ^-1 .

Further, the reaction temperature of the above epoxidation reaction is 30 to 90 ° C; preferably 40 to 80 ° C.

Further, the epoxidation reaction is carried out in a reduced pressure system, and the vacuum degree of the reduced pressure system is preferably 5 to 65 kPa, and more preferably 20 to 60 kPa.

Further, the above method comprises: in a reduced pressure system, feeding chloropropene from the bottom into a reactor containing a modified heteropolyacid supported catalyst, and sending hydrogen peroxide from the top to the reactor to make chloropropene and hydrogen peroxide The epoxidation reaction takes place to obtain epichlorohydrin, and preferably the reactor is a fixed bed reactor.

According to still another aspect of the present invention, there is provided a modified heteropolyacid supported catalyst having the following structural formula I:

Wherein n is any one of 3 to 20, a is an integer of 250 to 300, b is an integer of 10 to 50, and R ₁ , R ₂ and R ₃ are each independently selected from C ₁ Any one of -C ₁₀ hydrocarbon groups.

Further, the above n is an integer of any one of 7 to 14, and R ₁ , R ₂ and R ₃ are each independently selected from any one of C ₁ to C ₄ alkyl groups.

According to still another aspect of the present invention, there is provided a method for preparing a modified heteropolyacid supported catalyst, the preparation method comprising: Step S1, mixing an organic solution of a quaternary ammonium salt with peroxophosphoric acid and reacting to form The heteropolyacid monomer of the formula II has the structural formula II:

Wherein n is any one of 3 to 20, and R ₁ , R ₂ and R ₃ are each independently selected from any one of C ₁ to C ₄ alkyl groups; and step S2, heteropoly acid monomer and N are - Isopropyl acrylamide is subjected to a polymerization reaction to obtain a modified heteropoly acid supported catalyst.

Further, the organic solvent of the above organic solution is any one or more selected from the group consisting of methyl chloride, dichloromethane, chloroform, carbon tetrachloride and dichloroethane. Preferably, the structural formula of the quaternary ammonium salt is

n is an integer of any one of 3 to 20, preferably any one of 7 to 14; preferably, the reaction temperature of the reaction of the quaternary ammonium salt with the peroxophosphoric acid is 10 to 60 ° C, preferably 20 to 40 ° C, and the reaction is carried out. The time is from 1 to 10 h, preferably from 3 to 5 h.

Further, the above step S2 includes:

The heteropoly acid monomer and N-isopropyl acrylamide are polymerized in the presence of a radical initiator and a solvent, preferably the radical initiator is azobisisobutyronitrile, azobisisoheptonitrile or uncle Butyl hydrogen peroxide or the like; the solvent is N,N-dimethylformamide, N,N-dimethylacetamide or dimethyl sulfoxide; preferably the polymerization temperature is 60 to 80 ° C; preferably N-isopropyl The molar ratio of the acrylamide to the quaternary ammonium salt is from 5 to 25:1, preferably from 7 to 10:1.

By applying the technical scheme of the present invention, the present invention adopts a modified heteropoly acid supported catalyst having the above formula, and it is verified by experiments that the catalyst can catalyze the epoxidation of chloropropene and hydrogen peroxide to avoid epichlorohydrin under acidic conditions. The side reaction with water hydrolysis, so that the yield and selectivity of epichlorohydrin is improved; at the same time, the catalyst can be used to reduce the amount of chloropropene, even if the molar ratio of chloropropene to hydrogen peroxide is less than 4:1 It is also possible to achieve a higher yield of epichlorohydrin, thus lowering the cost of the raw material; further, since the catalyst of the present application is a supported catalyst, the recovery rate of the catalyst is high, and the catalyst cost is saved.

DRAWINGS

The accompanying drawings, which are incorporated in the claims of the claims In the drawing:

Figure 1 is a reaction flow diagram of the present invention.

detailed description

It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict. The invention will be described in detail below with reference to the drawings in conjunction with the embodiments.

As analyzed by the background art of the present application, the consumption of chloropropene in the preparation of the prior art epichlorohydrin is high, resulting in higher cost. In order to solve the problem, the present application provides a method for preparing epichlorohydrin by direct epoxidation of chloropropene, a modified heteropoly acid supported catalyst, and a preparation method thereof.

In an exemplary embodiment of the present application, there is provided a process for the direct epoxidation of chloropropene to produce epichlorohydrin, which comprises: catalyzing the reaction of chloropropene and hydrogen peroxide with a modified heteropolyacid supported catalyst. The oxidation reaction produces epichlorohydrin, wherein the modified heteropolyacid supported catalyst has the following structural formula I:

Wherein n is any one of 3 to 20, a is an integer of 250 to 300, b is an integer of 10 to 50, and R ₁ , R ₂ and R ₃ are each independently selected from C ₁ Any one of -C ₁₀ hydrocarbon groups.

The present invention adopts a modified heteropolyacid supported catalyst having the above formula, and it is verified by experiments that the catalyst can catalyze the epoxidation of chloropropene and hydrogen peroxide, and can avoid the side reaction of epichlorohydrin with water under acidic conditions. Therefore, the yield and selectivity of epichlorohydrin are improved; at the same time, the amount of chloropropene can be reduced when the catalyst is used, even if the molar ratio of chloropropene to hydrogen peroxide is less than 4:1, a higher ring can be realized. The oxychloropropane yield, thus reducing the cost of the raw material; further, since the catalyst of the present application is a supported catalyst, the recovery rate of the catalyst is high, and the catalyst cost is saved.

In order to further increase the selectivity of the catalyst, it is preferred that in the above formula I, n is any one of 7 to 14, and R ₁ , R ₂ and R ₃ are each independently selected from C ₁ to C ₄ alkyl groups. One.

As described above, the amount of the chloropropene used in the present application is reduced, and it is preferred that the molar ratio of the above chloropropene to hydrogen peroxide is from 0.85 to 2.00:1, more preferably from 0.95 to 1.50:1. In the above molar ratio range, a low amount of chloropropene is ensured, and a high yield and selectivity of epichlorohydrin can be ensured.

In order to further increase the conversion of chloropropene, it is preferred that the above-mentioned chloropropene feed mass space velocity is from 1.5 to 10.0 h ^-1 , preferably from 3.0 to 6.0 h ^-1 .

The temperature of the epoxidation reaction of the present application may be a temperature conventionally used in the prior art, and it is preferred that the reaction temperature of the above epoxidation reaction is 30 to 90 ° C; more preferably 40 to 80 ° C. To further ensure the efficient and stable reaction.

In one embodiment of the present application, the epoxidation reaction is carried out in a reduced pressure system, and preferably, the vacuum degree of the reduced pressure system is 5 to 65 kPa, and more preferably 20 to 60 kPa. By controlling the pressure of the reaction system, on the one hand, the safety of the reaction is improved, and on the other hand, the separation of the product is facilitated.

In another embodiment of the present application, the method comprises: feeding chloropropene from a bottom into a reactor containing a modified heteropolyacid supported catalyst in a reduced pressure system, and sending hydrogen peroxide from the top to the reaction. The epoxidation reaction of chloropropene and hydrogen peroxide is carried out to obtain epoxy chloropropene. Preferably, the reactor is a fixed bed reactor. The above epoxidation reaction is carried out in the reactor, and the obtained product and by-products can be directly separated from the reactor. For example, while the reaction, chloropropene, epichlorohydrin and water are stripped from the top of the reactor, one The chloropropanediol and another part of the water exit the system from the bottom of the reactor; the top reaction liquid oil moisture layer, the oil layer is cooled and the composition is determined, and the water layer is incorporated into the bottom reaction liquid, and then cooled to determine the composition. It can be seen that the epoxidation reaction and the product separation process are coupled in the above embodiment, thereby saving equipment and simplifying the entire process.

In another exemplary embodiment of the present application, a modified heteropolyacid supported catalyst is provided, and the modified heteropolyacid supported catalyst has the following structural formula I:

Wherein n is any one of 3 to 20, a is an integer of 250 to 300, b is an integer of 10 to 50, and R ₁ , R ₂ and R ₃ are each independently selected from C ₁ Any one of -C ₁₀ hydrocarbon groups.

It has been experimentally verified that the above catalyst can catalyze the epoxidation of chloropropene and hydrogen peroxide to avoid the side reaction of epichlorohydrin hydrolysis with water under acidic conditions, thereby improving the yield and selectivity of epichlorohydrin; When the catalyst is used, the amount of chloropropene can be reduced, even if the molar ratio of chloropropene to hydrogen peroxide is less than 4:1, a higher yield of epichlorohydrin can be achieved, thereby reducing the cost of raw materials; further due to the application of the present application The catalyst is a supported catalyst, so the recovery rate of the catalyst is high, and the catalyst cost is saved.

In order to further increase the selectivity of the catalyst, it is preferred that in the above formula I, n is any one of 7 to 14, and R ₁ , R ₂ and R ₃ are each independently selected from C ₁ to C ₄ alkyl groups. One.

In still another exemplary embodiment of the present application, there is provided a method for preparing a modified heteropolyacid supported catalyst, the preparation method comprising: Step S1, the organic solution of the quaternary ammonium salt and the peroxophosphoric acid After mixing, the reaction is carried out to form a heteropolyacid monomer having the structural formula II, and the structural formula II is:

Wherein n is any one of 3 to 20, and R ₁ , R ₂ and R ₃ are each independently selected from any one of C ₁ to C ₄ alkyl groups; and step S2, heteropoly acid monomer and N are - Isopropyl acrylamide is subjected to a polymerization reaction to obtain a modified heteropoly acid supported catalyst.

The heteropoly acid monomer having the above structural formula II is formed by using an organic solution of a quaternary ammonium salt and peroxophosphoric acid as a raw material, and then performing a polymerization reaction, and the process is simple and easy to implement.

In order to increase the reaction efficiency, it is preferred that the organic solvent of the organic solution is any one or more selected from the group consisting of methyl chloride, dichloromethane, chloroform, carbon tetrachloride and dichloroethane. Preferably, the structural formula of the quaternary ammonium salt is

n is an integer of any one of 3 to 20, preferably any one of 7 to 14; preferably, the reaction temperature of the reaction of the quaternary ammonium salt with the peroxophosphoric acid is 10 to 60 ° C, preferably 20 to 40 ° C, and the reaction is carried out. The time is from 1 to 10 h, preferably from 3 to 5 h.

The peroxyphosphoric acid of the present application can be prepared by a prior art preparation method. In order to improve the controllability of the preparation method of the present application and reduce the cost, it is preferred that the above step S1 includes a preparation process of peroxophosphoric acid, the preparation The process comprises: reacting sodium tungstate and phosphoric acid in an acidic aqueous solution to form a phosphotungstic acid solution under normal temperature and normal pressure; and oxidizing the phosphotungstic acid solution with hydrogen peroxide to form a peroxophosphoric acid solution, wherein the sodium tungstate and the phosphoric acid are moles The ratio is 3.0 to 5.0:1, preferably 3.5 to 4.5:1; preferably, the amount of water in the acidic aqueous solution is 3 to 10 times, more preferably 5 to 8 times the weight of the sodium tungstate; preferably the acid in the acidic aqueous solution is hydrochloric acid, preferably HCl. The molar ratio to sodium tungstate is from 1.5 to 3.0:1, more preferably from 2.0 to 2.5:1; preferably the molar ratio of hydrogen peroxide to sodium tungstate is from 1 to 10:1, more preferably from 3 to 8:1; preferably quaternary ammonium salt The molar ratio to sodium tungstate is 2.8 to 3.3:4, more preferably 3.0 to 3.2:4. The resulting peroxophosphoric acid solution is directly subjected to the next step of monomer preparation without purification.

In an embodiment of the present application, the step S2 includes: polymerizing the heteropoly acid monomer and the N-isopropyl acrylamide in the presence of a radical initiator and a solvent, preferably the radical initiator is Nitrogen diisobutyronitrile, azobisisoheptanenitrile or t-butyl hydroperoxide, the solvent is N,N-dimethylformamide, N,N-dimethylacetamide or dimethyl sulfoxide; preferably polymerization The temperature is 60 to 80 ° C; preferably, the molar ratio of N-isopropylacrylamide to quaternary ammonium salt is 5 to 25:1, preferably 7 to 10:1. The polymerization reaction is carried out under the above conditions, whereby the polymerization efficiency can be improved, and the molecular weight of the obtained catalyst can be easily adjusted.

The technical solutions and technical effects of the present invention will be described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto.

Catalyst Synthesis Example

Example 1-1

(1) Preparation of heteropoly acid monomer: Under normal temperature and pressure, 33.0 g of sodium tungstate and 3.8 g of 85% phosphoric acid are dissolved in 198.0 g of water, and the mass concentration is 30% hydrochloric acid 28.0 g. A phosphotungstic acid solution is formed under acidic conditions, and 54.4 g of a hydrogen peroxide solution of 50% hydrogen peroxide is added to the phosphotungstic acid solution to form a peroxophosphoric acid solution after oxidation; and the previously prepared mass concentration is 6 wt% [C ₅ H 206.7 g of a solution of ₁₁ N(CH ₃ ) ₃ ]Cl (linear quaternary ammonium salt) in dichloroethane (containing 12.4 g of quaternary ammonium salt) was added to the above-mentioned peroxophosphoric acid solution, and reacted at 20 ° C for 4 h. After the reaction, the product is centrifuged, washed, and dried to obtain 30.8 g of a heteropolyacid monomer I, and the yield is 86.9%;

(2) Polymerization of heteropoly acid monomer: 5.7 g of N-isopropyl acrylamide, 14.1 g of heteropoly acid monomer I, 0.1 g of a radical initiator azobisisobutyronitrile, and 0.1 g of a random pressure reactor were sequentially added thereto. Solvent N,N-dimethylformamide (or N,N-dimethylacetamide) 200g, and stir to dissolve the substances, remove oxygen, and then carry out polymerization at 70 ° C for 4h, after the end of the reaction, the product passed Precipitation, centrifugation, and drying gave 19.4 g of a supported heteropolyacid catalyst I.

Example 1-2

(1) Preparation of heteropoly acid monomer: under normal temperature and pressure, 33.0 g of sodium tungstate and 3.3 g of 85% phosphoric acid are dissolved in 99.0 g of water, and the mass concentration is 30% hydrochloric acid 30.4 g. A phosphotungstic acid solution is formed under acidic conditions, and 20.4 g of a hydrogen peroxide solution having a mass concentration of 50% hydrogen peroxide is added to the phosphotungstic acid solution to form a peroxophosphoric acid solution after oxidation; and the previously prepared mass concentration is 6 wt% [C ₁₈ H 450.0 g of a solution of ₃₅ N(CH ₃ ) ₃ ]Cl (linear quaternary ammonium salt) in dichloroethane (containing 27.0 g of quaternary ammonium salt) was added to a solution of peroxophosphoric acid and reacted at 30 ° C for 3 h. After the reaction, the product was centrifuged, washed and dried to obtain 45.9 g of heteropolyacid monomer II, and the yield was 95.2%;

(2) Polymerization of heteropoly acid monomer: 11.3 g of N-isopropyl acrylamide, 19.3 g of heteropoly acid monomer II, and a radical initiator azobisisobutyronitrile (or even) were sequentially added to the pressure resistant reaction bottle. 0.1 g of nitrogen diisoheptanenitrile and 200 g of solvent N,N-dimethylformamide, and the mixture was stirred to dissolve each substance, and oxygen was removed, and then polymerization was carried out at 70 ° C for 4 h. After the reaction, the product was precipitated and centrifuged. Drying gave 30.0 g of a supported heteropolyacid catalyst II.

Examples 1-3

(1) Preparation of heteropoly acid monomer: Under normal temperature and pressure, 33.0 g of sodium tungstate and 2.3 g of 85% phosphoric acid are dissolved in 264.0 g of water, and 24.3 g of 30% hydrochloric acid is added, and phosphorus tungsten is formed under acidic conditions. Acid solution, adding 68.0g of 50% hydrogen peroxide solution to the phosphotungstic acid solution, and oxidizing to form a peroxo-tungstic acid solution; and then pre-configured 6wt% [C ₁₃ H ₂₅ N(CH ₃ ) ₃ ]Cl (linear type) 328.3 g of a quaternary ammonium salt solution (containing 19.7 g of quaternary ammonium salt) was added to a solution of peroxophosphoric acid and reacted at 10 ° C for 1 h. After the reaction, the product was centrifuged, washed and dried to obtain a miscellaneous product. Polyacid monomer III 34.9g, the preparation yield was 79.3%;

(2) Polymerization of heteropoly acid monomer: 9.0 g of N-isopropylacrylamide, 17.6 g of heteropoly acid monomer III, and 0.1 g of a radical initiator azobisisobutyronitrile were sequentially added to a pressure resistant reaction bottle. Solvent N,N-dimethylformamide 200g, and stir to dissolve the substances, remove oxygen, and then carry out polymerization at 70 ° C for 4h, after the reaction is finished, the product is precipitated, centrifuged and dried to obtain a supported heteropolyacid. Catalyst III 26.1 g.

Examples 1-4

(1) Preparation of heteropoly acid monomer: Under normal temperature and pressure, 33.0 g of sodium tungstate and 2.9 g of 85% phosphoric acid are dissolved in 165.0 g of water, and 36.5 g of 30% hydrochloric acid is added, and phosphorus tungsten is formed under acidic conditions. Acid solution, adding 6.8g of 50% hydrogen peroxide solution to the phosphotungstic acid solution, and oxidizing to form a peroxo-tungstic acid solution; and then pre-configured 6wt% [C ₉ H ₁₇ N(CH ₃ ) ₃ ]Cl (linear type) 310.0 g of a quaternary ammonium salt solution (containing quaternary ammonium salt 18.6 g) was added to a solution of peroxophosphoric acid and reacted at 60 ° C for 5 h. After the reaction, the product was centrifuged, washed and dried to obtain a miscellaneous product. Polyacid monomer IV 36.9g, the preparation yield was 92.7%;

(2) Polymerization of heteropoly acid monomer: To the pressure resistant reaction bottle, 28.3 g of N-isopropylacrylamide, 14.5 g of heteropoly acid monomer, and azobisisobutyronitrile of free radical initiator (or uncle) were sequentially added. 0.1 g of butyl hydroperoxide and 200 g of solvent N,N-dimethylformamide (or dimethyl sulfoxide), and the mixture was dissolved to remove oxygen, and then polymerization was carried out at 70 ° C for 4 h. The product was precipitated, centrifuged, and dried to obtain 43.3 g of a supported heteropolyacid catalyst IV.

Examples 1-5

(1) Preparation of heteropoly acid monomer: Under normal temperature and pressure, 33.0 g of sodium tungstate and 2.6 g of 85% phosphoric acid are dissolved in 330.0 g of water, and 18.3 g of 30% hydrochloric acid is added, and phosphorus tungsten is formed under acidic conditions. Acid solution, adding 34.0g of 50% hydrogen peroxide solution to the phosphotungstic acid solution, and oxidizing to form a peroxo-tungstic acid solution; and then pre-configured 6wt% [C ₂₃ H ₄₅ N(CH ₃ ) ₃ ]Cl (linear type) 508.3 g of a quaternary ammonium salt solution (containing 30.5 g of quaternary ammonium salt) was added to a solution of peroxophosphoric acid and reacted at 40 ° C for 10 h. After the reaction, the product was centrifuged, washed and dried to obtain a miscellaneous product. The polyacid monomer V 49.3g, the preparation yield is 90.4%;

(2) Polymerization of heteropoly acid monomer: 7.9 g of N-isopropyl acrylamide, 21.8 g of heteropoly acid monomer V, and 0.1 g of a radical initiator azobisisobutyronitrile were sequentially added to a pressure resistant reaction bottle. And solvent N, N-dimethylformamide 200g, stirring to dissolve the substances, deoxidation, and then polymerization at 70 ° C for 4h, after the end of the reaction, the product was precipitated, centrifuged, dried to obtain a supported heteropolyacid Catalyst V 29.1 g.

Example 1-6

(1) The heteropoly acid monomer was prepared in the same manner as in Example 1-1.

(2) Polymerization of heteropoly acid monomer: 5.7 g of N-isopropyl acrylamide, 14.1 g of heteropoly acid monomer, and a radical initiator azobisisobutyronitrile (AIBN) were sequentially added to the pressure resistant reaction bottle. 0.1g and solvent N,N-dimethylformamide 200g, and stir to dissolve the substances, remove oxygen, and then carry out polymerization at 60 ° C for 5h. After the reaction is finished, the product is precipitated, centrifuged and dried to obtain a supported type. Heteropolyacid catalyst I 19.1 g.

Example 1-7

(1) The heteropoly acid monomer was prepared in the same manner as in Example 1-1.

(2) Polymerization of heteropoly acid monomer: 5.7 g of N-isopropyl acrylamide, 14.1 g of heteropoly acid monomer, and a radical initiator azobisisobutyronitrile (AIBN) were sequentially added to the pressure resistant reaction bottle. 0.1g and solvent N,N-dimethylformamide 200g, and stir to dissolve the substances, remove oxygen, and then carry out polymerization at 80 ° C for 4h. After the reaction is finished, the product is precipitated, centrifuged and dried to obtain a supported type. Heteropolyacid catalyst I 19.6 g.

Example 1-8

(1) Preparation of heteropoly acid monomer: Under normal temperature and pressure, 33.0 g of sodium tungstate and 2.6 g of 85% phosphoric acid are dissolved in 330.0 g of water, and 18.3 g of 30% hydrochloric acid is added, and phosphorus tungsten is formed under acidic conditions. Acid solution, add 34.0g of 50% hydrogen peroxide solution to the phosphotungstic acid solution, and oxidize to form a peroxo-tungstic acid solution; then pre-configured 6wt% [C ₂₃ H ₄₅ N(C ₄ H ₉ ) ₃ ]Cl (straight 508.3 g of a dichloroethane solution of a chain quaternary ammonium salt (containing 39.7 g of a quaternary ammonium salt) was added to a solution of peroxophosphoric acid and reacted at 40 ° C for 10 h. After the reaction, the product was centrifuged, washed, and dried. Obtaining 59.0 g of heteropoly acid monomer VI, the preparation yield is 92.5%;

(2) Polymerization of heteropoly acid monomer: 7.9 g of N-isopropyl acrylamide, 25.6 g of heteropoly acid monomer VI, and a radical initiator azobisisobutyronitrile (AIBN) were sequentially added to the pressure resistant reaction bottle. 0.1g and solvent N,N-dimethylformamide 200g, stir to dissolve the substance, remove oxygen, and then carry out polymerization at 70 ° C for 4h, after the end of the reaction, the product is precipitated, centrifuged and dried to obtain a supported type. Heteropolyacid catalyst VI 33.2g.

Epoxidation example

Example 2-1

309.0 g of chloropropene and 19.4 g of catalyst I were placed in a 500 mL four-necked flask, and the temperature was raised to reflux. 69.6 g of 49.1% hydrogen peroxide was added dropwise over 2 hours while stirring, and the reaction was continued for 3 hours at the reflux temperature. After the reaction was completed, centrifugation and standing were carried out. The epichlorohydrin oil layer and the water layer were layered, and the oil layer and the water layer were subjected to GC quantitative analysis of epichlorohydrin and 3-chloro-1,2-propanediol content, and the aqueous layer was used to determine the residual hydrogen peroxide content.

Example 2-2

309.0 g of chloropropene and 30.0 g of catalyst II were placed in a 500 mL four-necked flask, and the temperature was raised to reflux. 69.6 g of 49.1% hydrogen peroxide was added dropwise over 2 hours while stirring, and the reaction was continued for 5 hours at the reflux temperature. After the reaction was completed, centrifugation and standing were carried out. The epichlorohydrin oil layer and the water layer were layered, and the oil layer and the water layer were subjected to GC quantitative analysis of epichlorohydrin and 3-chloro-1,2-propanediol content, and the aqueous layer was used to determine the residual hydrogen peroxide content.

Example 2-3

309.0 g of chloropropene and 26.1 g of catalyst III were placed in a 500 mL four-necked flask, and the temperature was raised to reflux. 69.6 g of 49.1% hydrogen peroxide was added dropwise thereto over 2 hours while stirring, and the reaction was continued for 1 hour at the reflux temperature. After the reaction was completed, centrifugation and standing were carried out. The epichlorohydrin oil layer and the water layer were layered, and the oil layer and the water layer were subjected to GC quantitative analysis of epichlorohydrin and 3-chloro-1,2-propanediol content, and the aqueous layer was used to determine the residual hydrogen peroxide content.

Example 2-4

309.0 g of chloropropene and 43.3 g of catalyst IV were placed in a 500 mL four-necked flask, and the mixture was heated to reflux. 69.6 g of 49.1% hydrogen peroxide was added dropwise thereto over 1 h with stirring, and reacted at reflux temperature for 3 hours. After the reaction was completed, centrifugation and standing stratification were carried out. The epichlorohydrin oil layer and the water layer, the oil layer and the water layer were subjected to GC quantitative analysis of epichlorohydrin and 3-chloro-1,2-propanediol content, and the aqueous layer was used to determine the residual hydrogen peroxide content.

Example 2-5

309.0 g of chloropropene and 29.1 g of catalyst V were placed in a 500 mL four-necked flask, and the temperature was raised to reflux. 69.6 g of 49.1% hydrogen peroxide was added dropwise thereto over 2 hours while stirring, and the reaction was carried out for 4 hours at the reflux temperature. After the reaction was completed, centrifugation and standing stratification were carried out. The epichlorohydrin oil layer and the water layer, the oil layer and the water layer were subjected to GC quantitative analysis of epichlorohydrin and 3-chloro-1,2-propanediol content, and the aqueous layer was used to determine the residual hydrogen peroxide content.

Example 2-6

309.0 g of chloropropene and 33.2 g of catalyst VI were placed in a 500 mL four-necked flask, and the temperature was raised to reflux. 69.6 g of 49.1% hydrogen peroxide was added dropwise thereto over 2 hours while stirring, and the reaction was carried out for 4 hours at the reflux temperature. After the reaction was completed, centrifugation and standing stratification were carried out. The epichlorohydrin oil layer and the water layer, the oil layer and the water layer were subjected to GC quantitative analysis of epichlorohydrin and 3-chloro-1,2-propanediol content, and the aqueous layer was used to determine the residual hydrogen peroxide content.

Comparative Example 2-1

309.0 g of chloropropene and 14.1 g of heteropolyacid monomer I were placed in a 500 mL four-necked flask, and the temperature was raised to reflux. 69.6 g of 49.1% hydrogen peroxide was added dropwise thereto for 2 hours while stirring, and the reaction was continued for 3 hours at the reflux temperature; The epichlorohydrin oil layer and the water layer were separated and layered, and the oil layer and the water layer were subjected to GC quantitative analysis of epichlorohydrin and 3-chloro-1,2-propanediol content, and the aqueous layer was used to determine the residual hydrogen peroxide content.

Comparative Example 2-2

309.0 g of chloropropene and 21.8 g of heteropolyacid monomer V were placed in a 500 mL four-necked flask, and the temperature was raised to reflux. 69.6 g of 49.1% hydrogen peroxide was added dropwise thereto for 2 hours while stirring, and the reaction was carried out for 4 hours at the reflux temperature; The epichlorohydrin oil layer and the water layer were separated and layered, and the oil layer and the water layer were subjected to GC quantitative analysis of epichlorohydrin and 3-chloro-1,2-propanediol content, and the aqueous layer was used to determine the residual hydrogen peroxide content.

Calculate the selectivity of epichlorohydrin, the selectivity of 3-chloro-1,2-propanediol, the conversion rate of hydrogen peroxide, and the utilization of the epichlorohydrin, 3-chloro-1,2-propanediol, and hydrogen peroxide content measured above. rate.

The reaction solution is recovered by centrifugation, and the dry weight of the catalyst is recovered by vacuum drying; the catalyst dry basis is determined by ICP to determine P and W, and the catalyst recovery rate is obtained. The specific results are shown in Table 1.

Table 1

Example 2-7

309.0 g of chloropropene and 30.0 g of catalyst II were placed in a 500 mL four-necked flask, and the temperature was raised to reflux. 69.6 g of 49.1% hydrogen peroxide was added dropwise thereto for 2 hours while stirring, and the reaction was carried out for 2 hours at the reflux temperature. After the reaction was completed, centrifugation and standing stratification were carried out. The epichlorohydrin oil layer and the water layer, the oil layer and the water layer were subjected to GC quantitative analysis of epichlorohydrin and 3-chloro-1,2-propanediol content, and the aqueous layer was used to determine the residual hydrogen peroxide content. The catalyst was recovered, and 0.24 g of a new catalyst was added and recycled for 5 times. The catalytic situation is shown in Table 2 below.

Table 2

Example 3-1

Using a metering pump, the chloropropene was pumped from the bottom into a fixed-bed reactor equipped with a self-modified heteropolyacid-supported catalyst I at a space velocity of 8.0 h ^{-1 .} The ratio of hydrogen peroxide to chloropropene was 1:1.10. The top is pumped into a fixed bed reactor and reacted at 30 ° C and a system vacuum of 5 KPa; while reacting, chloropropene, epichlorohydrin and water are stripped from the top of the reactor, monochloropropanediol and another portion of water from the reactor The bottom of the reactor exits the system; the top reactant oil moisture layer, after the oil layer is cooled, the composition is chloropropene 26.1%, epichlorohydrin 73.5% and water 0.4%, and the water layer is combined into the bottom reaction liquid and then cooled to form hydrogen peroxide 0.5%. , epichlorohydrin 1.5%, chloropropanediol 3.4% and water 94.6%, hydrogen peroxide conversion rate of 99.0%, epichlorohydrin and monochloropropanediol yields of 69.0% and 2.1%, respectively, and epichlorohydrin selectivity 97.1% and hydrogen peroxide utilization rate was 71.7%. The above process can refer to FIG. 1.

Example 3-2

Using a metering pump, the chloropropene was pumped from the bottom into a fixed-bed reactor equipped with a self-modified heteropolyacid supported catalyst II at a space velocity of 4.0 h ^{-1 .} The ratio of hydrogen peroxide to chloropropene was 1:1.20. The top is pumped into a fixed bed reactor and reacted at 60 ° C and a system vacuum of 20 kPa; while reacting, chloropropene, epichlorohydrin and water are stripped from the top of the reactor, monochloropropanediol and another portion of water from the reactor The bottom of the reactor exits the system; the top reactant oil moisture layer, after the oil layer is cooled, the composition is 11.4% of chloropropene, 88.1% of epichlorohydrin and 0.5% of water. The water layer is combined into the bottom reaction liquid and then cooled to form hydrogen peroxide 0.4%. , epichlorohydrin 1.3%, monochloropropanediol 4.5% and water 93.8%, hydrogen peroxide conversion rate 99.2%, epichlorohydrin and monochloropropanediol yields 89.7% and 2.7%, respectively, epichlorohydrin selectivity 97.0% and hydrogen peroxide utilization rate was 93.2%.

Example 3-3

Using a metering pump, the chloropropene was pumped from the bottom into a fixed-bed reactor equipped with a self-modified heteropolyacid-supported catalyst IV at a space velocity of 10.0 h ^{-1 .} The ratio of hydrogen peroxide to chloropropene was 1:0.90. The top is pumped into a fixed bed reactor and reacted at 60 ° C and a system vacuum of 15 kPa; while reacting, chloropropene, epichlorohydrin and water are stripped from the top of the reactor, monochloropropanediol and another portion of water from the reactor The bottom of the reactor exits the system; the top reactant oil moisture layer, after the oil layer is cooled, the composition is 21.9% of chloropropene, 77.5% of epichlorohydrin and 0.6% of water, and the water layer is combined into the bottom reaction liquid and then cooled to form hydrogen peroxide 0.3%. , epichlorohydrin 1.6%, monochloropropanediol 5.4% and water 92.7%, hydrogen peroxide conversion rate 99.4%, epichlorohydrin and monochloropropanediol yields 59.7% and 3.3%, respectively, epichlorohydrin selectivity 94.8% and hydrogen peroxide utilization rate was 63.4%.

Example 3-4

Using a metering pump, the chloropropene was pumped from the bottom into a fixed-bed reactor equipped with a self-modified heteropolyacid supported catalyst III at a space velocity of 6.0 h ^{-1 .} The ratio of hydrogen peroxide to chloropropene was 1:1.50. The top is pumped into a fixed bed reactor and reacted at 50 ° C and a system vacuum of 15 kPa; while reacting, chloropropene, epichlorohydrin and water are stripped from the top of the reactor, monochloropropanediol and another portion of water from the reactor The bottom of the reactor exits the system; the top reactant oil moisture layer, after the oil layer is cooled, the composition is 21.9% of chloropropene, 77.5% of epichlorohydrin and 0.6% of water. The water layer is combined into the bottom reaction liquid and then cooled to form hydrogen peroxide 0.5%. , epichlorohydrin 1.8%, monochloropropanediol 4.1% and water 93.6%, hydrogen peroxide conversion rate of 99.0%, epichlorohydrin and monochloropropanediol yields of 84.9% and 2.5%, respectively, and epichlorohydrin selectivity 97.2% and hydrogen peroxide utilization rate was 88.3%.

Example 3-5

Using a metering pump, the chloropropene was pumped from the bottom into a fixed-bed reactor equipped with a self-modified heteropolyacid supported catalyst V at a space velocity of 3.0 h ^{-1 .} The ratio of hydrogen peroxide to chloropropene was 1:2.00. The top is pumped into a fixed bed reactor and reacted at 90 ° C and a system vacuum of 60 kPa; while reacting, chloropropene, epichlorohydrin and water are stripped from the top of the reactor, monochloropropanediol and another portion of water from the reactor The bottom of the reactor exits the system; the top reactant oil moisture layer, after the oil layer is cooled, the composition is 46.4% of chloropropene, 52.9% of epichlorohydrin and 0.7% of water. The water layer is combined into the bottom reaction liquid and then cooled to form hydrogen peroxide 0.1%. , epichlorohydrin 1.1%, monochloropropanediol 7.3% and water 91.5%, hydrogen peroxide conversion rate of 99.8%, epichlorohydrin and monochloropropanediol yields of 89.6% and 4.4%, respectively, and epichlorohydrin selectivity The utilization rate of 95.3% and hydrogen peroxide was 94.2%.

Example 3-6

Using a metering pump, the chloropropene was pumped from the bottom into a fixed-bed reactor equipped with a self-modified heteropolyacid-supported catalyst V at a space velocity of 2.0 h ^{-1 .} The ratio of hydrogen peroxide to chloropropene was 1:1.30. The top is pumped into a fixed bed reactor and reacted at 80 ° C and atmospheric pressure; while reacting, chloropropene, epichlorohydrin and water are stripped from the top of the reactor, monochloropropanediol and another portion of water from the reactor The bottom outlet system; the top reactant oil moisture layer, after the oil layer is cooled, the composition is chloropropene 15.9%, epichlorohydrin 83.3% and water 0.8%. The water layer is combined into the bottom reaction liquid and then cooled to form hydrogen peroxide 0.1%, epoxy. Chloropropane 1.2%, chloropropanediol 6.4% and water 92.3%, hydrogen peroxide conversion rate of 99.8%, epichlorohydrin and monochloropropanediol yields of 91.8% and 3.9%, and epichlorohydrin selectivity of 95.9% and The hydrogen peroxide utilization rate is 95.8%.

Example 3-7

Using a metering pump, the chloropropene was pumped from the bottom into a fixed-bed reactor equipped with a self-modified heteropolyacid-supported catalyst II at a space velocity of 3.0 h ^{-1 .} The ratio of hydrogen peroxide to chloropropene was 1:1.10. The top is pumped into a fixed bed reactor and reacted at 60 ° C and a system vacuum of 20 kPa; while reacting, chloropropene, epichlorohydrin and water are stripped from the top of the reactor, monochloropropanediol and another portion of water from the reactor The bottom of the reactor exits the system; the top reactant oil moisture layer, after the oil layer is cooled, the composition is chloropropene 3.1%, epichlorohydrin 96.5% and water 0.4%, and the water layer is combined into the bottom reaction liquid and then cooled to form hydrogen peroxide 0.2%. , epichlorohydrin 1.7%, monochloropropanediol 4.8% and water 93.3%, hydrogen peroxide conversion rate of 99.6%, epichlorohydrin and monochloropropanediol yields of 90.3% and 2.9%, respectively, and epichlorohydrin selectivity The utilization rate of 96.9% and hydrogen peroxide was 93.6%.

Example 3-8

Using a metering pump, the chloropropene was pumped from the bottom into a fixed-bed reactor equipped with a self-modified heteropolyacid-supported catalyst I at a space velocity of 4.0 h ^{-1 .} The ratio of hydrogen peroxide to chloropropene was 1:1.20. The top is pumped into a fixed bed reactor and reacted at 70 ° C and a system vacuum of 40 kPa; while reacting, chloropropene, epichlorohydrin and water are stripped from the top of the reactor, monochloropropanediol and another portion of water from the reactor The bottom of the reactor was out of the system; for a total of 500 h, the catalyst activity was stable. The top reactant oil moisture layer, after the oil layer is cooled, the composition is chloropropene 9.6%, epichlorohydrin 89.9% and water 0.5%. The water layer is combined into the bottom reaction liquid and then cooled to form hydrogen peroxide 0.3% and epichlorohydrin 1.3%. 1, chloropropanediol 5.4% and water 93.0%, hydrogen peroxide conversion rate of 99.4%, epichlorohydrin and monochloropropanediol yields of 91.5% and 3.3%, epichlorohydrin selectivity of 96.5% and hydrogen peroxide utilization rate 95.3%.

Example 3-9

Using a metering pump, the chloropropene was pumped from the bottom into a fixed-bed reactor equipped with a self-modified heteropolyacid-supported catalyst V at a space velocity of 3.0 h ^{-1 .} The ratio of hydrogen peroxide to chloropropene was 1:0.85. The top is pumped into a fixed bed reactor and reacted at 50 ° C and a system vacuum of 50 kPa; while reacting, chloropropene, epichlorohydrin and water are stripped from the top of the reactor, monochloropropanediol and another portion of water from the reactor The bottom of the reactor exits the system; the top reactant oil moisture layer, after the oil layer is cooled, the composition is epichlorohydrin 99.6% and water 0.4%. The water layer is combined into the bottom reaction liquid and then cooled to form hydrogen peroxide 0.3%, epichlorohydrin. 1.8%, 1-chloropropanediol 0.5% and water 97.4%, hydrogen peroxide conversion rate 99.4%, epichlorohydrin and monochloropropanediol yields 77.2% and 0.3%, epichlorohydrin selectivity 99.6% and hydrogen peroxide utilization The rate is 77.9%.

Example 3-10

Using a metering pump, the chloropropene was pumped from the bottom into a fixed-bed reactor equipped with a self-modified heteropolyacid supported catalyst III at a space velocity of 3.0 h ^{-1 .} The ratio of hydrogen peroxide to chloropropene was 1:0.99. The top is pumped into a fixed bed reactor and reacted at 60 ° C and a system vacuum of 20 kPa; while reacting, chloropropene, epichlorohydrin and water are stripped from the top of the reactor, monochloropropanediol and another portion of water from the reactor The bottom of the reactor exits the system; the top reactant oil moisture layer, after the oil layer is cooled, the composition is 0.1% of chloropropene, 99.5% of epichlorohydrin and 0.4% of water. The water layer is combined into the bottom reaction liquid and then cooled to form 0.5% hydrogen peroxide. , epichlorohydrin 1.9%, monochloropropanediol 5.7% and water 91.9%, hydrogen peroxide conversion rate 99.1%, epichlorohydrin and monochloropropanediol yields 87.3% and 3.3%, respectively, epichlorohydrin selectivity The utilization rate of 96.3% and hydrogen peroxide was 91.5%.

Example 3-11

Using a metering pump, the chloropropene was pumped from the bottom into a fixed-bed reactor equipped with a self-modified heteropolyacid supported catalyst III at a space velocity of 3.0 h ^{-1 .} The ratio of hydrogen peroxide to chloropropene was 1:0.99. The top is pumped into a fixed bed reactor and reacted at 40 ° C and a system vacuum of 20 kPa; while reacting, chloropropene, epichlorohydrin and water are stripped from the top of the reactor, monochloropropanediol and another portion of water from the reaction The bottom of the reactor exits the system; the top reactant oil moisture layer, after the oil layer is cooled, the composition is 0.21% of chloropropene, 99.5% of epichlorohydrin and 0.34% of water. The aqueous layer is combined into the bottom reaction liquid and then cooled to form 0.8% hydrogen peroxide. , epichlorohydrin 1.6%, monochloropropanediol 5.6% and water 91.9%, hydrogen peroxide conversion rate of 98.51%, epichlorohydrin and monochloropropanediol yields of 87.1% and 3.1%, respectively, and epichlorohydrin selectivity 96.5% and hydrogen peroxide utilization rate was 90.8%.

Example 3-12

Using a metering pump, the chloropropene was pumped from the bottom into a fixed-bed reactor equipped with a self-modified heteropolyacid-supported catalyst VI at a space velocity of 1.5 h ^{-1 .} The ratio of hydrogen peroxide to chloropropene was 1:0.95. The top is pumped into a fixed bed reactor and reacted at 30 ° C and a system vacuum of 65 kPa; while reacting, chloropropene, epichlorohydrin and water are stripped from the top of the reactor, monochloropropanediol and another portion of water from the reactor The bottom of the reactor exits the system; the top reactant oil moisture layer, after the oil layer is cooled, the composition is 0.2% of chloropropene, 99.3% of epichlorohydrin and 0.5% of water. The water layer is combined into the bottom reaction liquid and then cooled to form hydrogen peroxide 0.1%. , epichlorohydrin 1.7%, monochloropropanediol 5.5% and water 92.7%, hydrogen peroxide conversion rate of 99.8%, epichlorohydrin and monochloropropanediol yields of 86.9% and 2.8%, respectively, and epichlorohydrin selectivity 96.9% and hydrogen peroxide utilization rate was 93.4%.

The above description is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims (20)

1. A method for preparing epichlorohydrin by direct epoxidation of chloropropene, characterized in that in a vacuum system, a metering pump is used to pump chloropropene from the bottom into a modified heteropolyacid suspension at a certain space velocity. In the fixed bed reactor of the catalyst, hydrogen peroxide and chloropropene are pumped from the top into the fixed bed reactor at a certain molar ratio, and reacted under a certain temperature and pressure; while reacting, the reaction of chloropropene, epichlorohydrin and water from the reaction The top stripping system of the apparatus, the monochloropropanediol and another part of the water exit the system from the bottom of the reactor; the top reaction liquid oil moisture layer, the oil layer is cooled and the composition is determined, the water layer is incorporated into the bottom reaction liquid, and then cooled to determine the composition.
2. The method of claim 1 wherein said molar ratio of chloropropene to hydrogen peroxide is from 0.85 to 2.00:1.
3. The method of claim 2 wherein said molar ratio of chloropropene to hydrogen peroxide is from 0.95 to 1.50:1.
4. The method of claim 1 wherein said chloropropene feed mass space velocity is from 1.5 to 10.0 h ^-1 .
5. The method of claim 4 wherein said chloropropene feed mass space velocity is from 3.0 to 6.0 h ^-1 .
6. The method according to claim 1, wherein said reaction temperature is 30 to 90 ° C; and the vacuum system has a vacuum of 5 to 65 kPa.
7. The method according to claim 6, wherein said reaction temperature is 40 to 80 ° C; and the vacuum degree of vacuum system is 20 to 60 kPa.
8. The method according to claim 1, wherein said modified heteropolyacid supported catalyst has the following structural formula I:

   

   Wherein, n is any one of 3 to 20, preferably any one of 7 to 14, and a is an integer of 250 to 300, and b is an integer of 10 to 50, and R ₁ and R ₂ And R ₃ are each independently selected from any one of C ₁ to C ₁₀ hydrocarbon groups, and further preferably each of R ₁ , R ₂ and R _{3 is} independently selected from a C ₁ -C ₄ alkyl group.
9. A method for preparing epichlorohydrin by direct epoxidation of chloropropene, characterized in that the method comprises:

   The modified heteropolyacid supported catalyst is used to catalyze the epoxidation of chloropropene and hydrogen peroxide to obtain epichlorohydrin, wherein the modified heteropolyacid supported catalyst has the following structural formula I:

   

   Wherein n is any one of 3 to 20, a is an integer of 250 to 300, b is an integer of 10 to 50, and R ₁ , R ₂ and R ₃ are each independently selected from C ₁ Any one of -C ₁₀ hydrocarbon groups.
10. The method according to claim 9, wherein said n is any one of 7 to 14, and each of R ₁ , R ₂ and R _{3 is} independently selected from C ₁ to C ₄ alkyl groups. One.
11. The method according to claim 9, wherein the molar ratio of the chloropropene to the hydrogen peroxide is from 0.85 to 2.00:1, preferably from 0.95 to 1.50:1.
12. The method according to claim 9, wherein the chloropropene feed mass space velocity is from 1.5 to 10.0 h ^-1 , preferably from 3.0 to 6.0 h ^-1 .
13. The method according to claim 9, wherein the reaction temperature of the epoxidation reaction is from 30 to 90 ° C; preferably from 40 to 80 ° C.
14. The method according to claim 9, wherein the epoxidation reaction is carried out in a reduced pressure system, and preferably the vacuum system has a degree of vacuum of 5 to 65 kPa, more preferably 20 to 60 kPa.
15. The method according to any one of claims 9 to 14, wherein the method comprises: feeding the chloropropene from the bottom into the modified heteropoly acid supported in a reduced pressure system In the reactor for the catalyst, the hydrogen peroxide is fed into the reactor from the top to epoxidize the chloropropene and the hydrogen peroxide to obtain the epichlorohydrin, preferably the reactor is fixed. Bed reactor.
16. A modified heteropolyacid supported catalyst characterized in that the modified heteropolyacid supported catalyst has the following structural formula I:

    

    Wherein n is any one of 3 to 20, a is an integer of 250 to 300, b is an integer of 10 to 50, and R ₁ , R ₂ and R ₃ are each independently selected from C ₁ Any one of -C ₁₀ hydrocarbon groups.
17. The modified heteropoly acid supported catalyst according to claim 16, wherein n is any one of 7 to 14, and R ₁ , R ₂ and R ₃ are each independently selected from C ₁ to Any of C ₄ alkyl groups.
18. The method for preparing a modified heteropolyacid supported catalyst according to claim 16 or 17, wherein the preparation method comprises:

    Step S1, reacting an organic solution of a quaternary ammonium salt with peroxophosphoric acid to form a heteropolyacid monomer having the structural formula II, wherein the structural formula II is:

    

    Wherein n is any one of from 3 to 20, and R ₁ , R ₂ and R ₃ are each independently selected from any one of C ₁ to C ₄ alkyl;

    In step S2, the heteropolyacid monomer is polymerized with N-isopropylacrylamide to obtain the modified heteropolyacid immobilization catalyst.
19. The preparation method according to claim 18, wherein the organic solvent of the organic solution is any one or more of the group consisting of methyl chloride, dichloromethane, chloroform, carbon tetrachloride and dichloroethane. Preferably, the structural formula of the quaternary ammonium salt is

    

    The n is any one of 3 to 20, preferably any one of 7 to 14. The reaction temperature of the reaction of the quaternary ammonium salt with the peroxophosphoric acid is preferably 10 to 60 ° C, preferably 20 to The reaction time is 40 to 1, and the reaction time is 1 to 10 hours, preferably 3 to 5 hours.
20. The preparation method according to claim 18, wherein the step S2 comprises:

    Carrying out the polymerization reaction of the heteropoly acid monomer and N-isopropyl acrylamide in the presence of a radical initiator and a solvent, preferably the radical initiator is azobisisobutyronitrile, azo Diisoheptanenitrile or t-butyl hydroperoxide; etc.; the solvent is N,N-dimethylformamide, N,N-dimethylacetamide or dimethyl sulfoxide; preferably the temperature of the polymerization is 60 to 80 ° C; preferably, the molar ratio of the N-isopropylacrylamide to the quaternary ammonium salt is 5 to 25:1, preferably 7 to 10:1.

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