WO2022057931A1

WO2022057931A1 - Continuous synthesis process and continuous reaction device for epichlorohydrin

Info

Publication number: WO2022057931A1
Application number: PCT/CN2021/119424
Authority: WO
Inventors: 徐林; 黄杰军; 丁克鸿; 李幸霏; 李明; 邓生财; 黄文嵘; 徐文轩; 钱赟; 胡金良; 徐志斌
Original assignee: 江苏扬农化工集团有限公司
Priority date: 2020-09-21
Filing date: 2021-09-18
Publication date: 2022-03-24
Also published as: CN111978273A; KR20230092922A

Abstract

The present invention provides a continuous synthesis process and a continuous reaction device for epichlorohydrin. The continuous synthesis process comprises placing hydrogen peroxide, methanol, chloropropene, and a catalyst into a reactor and performing an epoxidation reaction, wherein the reactor is a loop reactor, preloading the catalyst into the loop reactor, forming, in a chloropropene/methanol mixing apparatus, the chloropropene and the methanol into a chloropropene-methanol mixed liquid, then pumping same into the loop reactor by a metering pump A, and pumping the hydrogen peroxide into the loop reactor by a metering pump B at the same time. In the synthesis process of the present invention, less methanol is used, the catalyst has a long service life, the process device is simple, and continuous operation is achieved. In long-term continuous operation, the synthesis process can obtain a relatively stable hydrogen peroxide conversion rate and relatively high epichlorohydrin selectivity, and is applicable to the catalytic synthesis of epichlorohydrin.

Description

Continuous synthesis process and continuous reaction device of epichlorohydrin

technical field

The invention relates to the field of catalytic synthesis, in particular to a continuous synthesis process of epichlorohydrin and a continuous reaction device.

Background technique

Epichlorohydrin is an important organic chemical raw material and fine chemical product. Because its molecule contains active epoxy groups and chlorine atoms, its chemical properties are quite active, and it has become an important basic organic chemical raw material and intermediate. It is widely used in the synthesis of epoxy resin, glycerin, alcohol rubber, medicine, pesticide, surfactant, glass fiber reinforced plastic, ion exchange resin, coating and plasticizer.

At present, research at home and abroad mainly focuses on the process of preparing epichlorohydrin by direct epoxidation of chloropropene using hydrogen peroxide as the oxygen source. This process route does not produce salt-containing wastewater, only the water generated by the reaction, which has high atomic utilization and pollution. little. CN101124044A discloses a production process of epichlorohydrin. Using titanium-silicon molecular sieve as catalyst and methanol as solvent, epichlorohydrin is directly epoxidized to prepare epichlorohydrin; It is configured into a homogeneous phase with hydrogen peroxide. At a certain temperature, it is pumped into a fixed bed for the reaction. This reaction requires the feed to be configured into a homogeneous phase, so a large amount of methanol needs to be used, and the recovery energy consumption of methanol is relatively high. CN102093313A introduces a method for preparing epichlorohydrin. Hydrogen peroxide, methanol, chloropropene and catalyst are put into a reactor for direct epoxidation reaction, and the reacted liquid-solid mixture is subjected to membrane separation to obtain a solid part and a liquid part. Part is the catalyst, and the liquid part is separated and refined to obtain epichlorohydrin. The catalyst in this process has a short usage time, and the catalyst needs to be regenerated for each reaction, the process is complicated, and the energy consumption is high.

SUMMARY OF THE INVENTION

The main purpose of the present invention is to provide a continuous synthesis process of epichlorohydrin and a continuous reaction device, overcome the deficiencies in the epichlorohydrin synthesis process in the above-mentioned background technology, and adopt a loop reactor to provide a methanol dosage The epichlorohydrin synthesis process with few process devices, simple process device and continuous operation can solve the problems of high energy consumption for epichlorohydrin synthesis and short service life of catalysts in the prior art.

In order to implement the above object, according to one aspect of the present invention, a continuous synthesis process of epichlorohydrin is provided, the reactant and the catalyst are carried out in a loop reactor for continuous epoxidation reaction, and the reactant includes hydrogen peroxide, methanol and allyl chloride.

Further, the catalyst is preloaded into the loop reactor.

Further, allyl chloride and methanol are formed in a methanol/chloropropene mixing device to form a mixture of allyl chloride and methanol, which is pumped into the loop reactor by a metering pump A.

Further, hydrogen peroxide, methanol, allyl chloride and the catalyst are put into the loop reactor to carry out epoxidation reaction, the catalyst is preloaded into the loop reactor, and the allyl chloride and methanol are formed in the methanol/chloropropene mixing device to form allyl chloride. The methanol mixture is pumped into the loop reactor by the metering pump A, and the hydrogen peroxide is pumped into the loop reactor by the metering pump B at the same time.

Further, the catalyst is a TS-1 catalyst.

Further, the catalyst is packed in one stage or more.

Further, the loop reactor is also connected with other components, and the other components include a forced circulation pump, a mixer, a sedimentation tank or a centrifugal device, a production valve, and a reaction liquid collection device.

Further, the outlet of the loop reactor is also connected with a filter.

Further, the filter is a ceramic filter.

Further, the molar ratio of allyl chloride and hydrogen peroxide is 1-4:1.

Further, the molar ratio of methanol to hydrogen peroxide is 1-5:1.

Further, the hydrogen peroxide concentration is 10-70%.

Further, the reaction temperature is 0-80°C.

Further, the residence time of the reactants in the loop reactor is 0.1-10 h.

Further, the reaction pressure is 0.1-1 MPa.

According to another aspect of the present invention, a continuous reaction device is provided. The continuous reaction device includes: a hydrogen peroxide supply device, a methanol/chloropropene mixing device, and a loop reactor for realizing the continuous reaction. The loop reaction The device is communicated with hydrogen peroxide supply equipment and methanol/propylene chloride mixing equipment.

Further, the continuous reaction device also includes a heating device arranged along the circumference of the outer wall of the loop reactor.

Further, the heating device includes a heating jacket.

Further, the loop reactor includes: a curved reaction tube section, the curved reaction tube section includes a plurality of U-shaped connected reaction tubes; a straight tube section: communicated with the ends of the U-shaped reaction tubes at both ends of the curved reaction tube section; and a forced circulation pump, forced to circulate The pump is arranged on the reaction line of the straight pipe section.

Further, the continuous reaction device further comprises a mixer, and the mixer is arranged on the pipeline connecting the hydrogen peroxide supply device and the methanol/chloropropene mixing device and the loop reactor.

Further, the continuous reaction device further comprises a sedimentation tank or a centrifugal device, and the sedimentation tank or the centrifugal device are arranged on the pipeline that the hydrogen peroxide supply device and the methanol/chloropropene mixing device are communicated with the loop reactor, and are located in the mixer and the loop reactor. between the devices.

Further, the continuous reaction device further comprises a metering pump A and a metering pump B, the metering pump A is arranged on the pipeline between the methanol/chloropropene mixing equipment and the mixer, and the metering pump B is arranged between the hydrogen peroxide supply equipment and the mixer. on the pipeline.

Further, the continuous reaction device further includes a reaction liquid collecting device, and the reaction liquid collecting device is communicated with the outlet of the loop reactor.

Further, the continuous reaction device further comprises a draw valve, and the draw valve is located on the pipeline connecting the reaction liquid collecting device and the outlet of the loop reactor.

Further, the continuous reaction device further comprises a filter, and the filter is arranged on the outlet of the loop reactor.

Further, the loop reactor also includes a catalyst, and the catalyst is pre-installed in the curved pipe section and the straight pipe section.

Further, the catalyst is packed in one stage or more.

Further, the filter is a ceramic filter.

Applying the technical scheme of the present invention, by designing a continuous reaction device including a loop reactor, using hydrogen peroxide, chloropropene and methanol as reactants to continuously synthesize epichlorohydrin, further, using a pre-installed TS-1 catalyst to optimize Feed ratio, reaction temperature, reaction pressure, reaction time and other conditions, continuous reaction to efficiently prepare epichlorohydrin, increase catalyst service life, reduce synthesis energy consumption, and can obtain relatively stable hydrogen peroxide conversion during long-term continuous operation. and higher epichlorohydrin yields.

Description of drawings

The accompanying drawings forming a part of the present application are used to provide further understanding of the present invention, and the exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the attached image:

Fig. 1 shows the schematic diagram of the continuous synthesis device according to Examples 1-6 of the present invention,

Wherein, the above-mentioned drawings include the following reference signs:

1. Methanol/propylene chloride mixing equipment; 2. Hydrogen peroxide supply equipment; 3. Metering pump A; 4. Metering pump B; 5. Forced circulation pump; 6. Reaction liquid collection equipment; 7. Filter; 8. Production valve 9, mixer; 10, settling tank or centrifugal equipment; 11, loop reactor; 12, I stage catalyst; 13, II stage catalyst; 14, III stage catalyst; 15, IV stage catalyst.

detailed description

It should be noted that the embodiments in the present application and the features of the embodiments may be combined with each other in the case of no conflict. The present invention will be described in detail below with reference to the embodiments.

As mentioned in the background art, the existing synthesis of epichlorohydrin mainly concentrates on using hydrogen peroxide as the oxygen source, and direct epoxidation of chloropropene to prepare epichlorohydrin. This reaction only generates water, with high atom utilization and little pollution. , in line with the development concept of green chemistry. However, the prior art utilizes hydrogen peroxide and chloropropene epoxidation to prepare epichlorohydrin, which requires a large amount of methanol, a short catalyst service life, and a complicated process, which is unfavorable for industrialized large-scale production.

Therefore, in the present application, the inventors tried to continuously synthesize epichlorohydrin, and found that the continuous synthesis method does not need to fully mix methanol with other reaction raw materials to form a homogeneous phase, the amount of methanol in the synthesis process is small, and the amount of methanol is reduced. The steps required for production; the catalyst has a long service life and can obtain relatively stable hydrogen peroxide conversion and high epichlorohydrin yield, so a series of protection schemes of the present application are proposed.

In the first typical embodiment of the present application, a continuous synthesis process of epichlorohydrin is provided, the reactants and the catalyst are carried out in a loop reactor for continuous epoxidation, and the reactants include hydrogen peroxide, methanol and allyl chloride. The combination of methanol and the catalyst provides a suitable catalytic environment for epoxidation. The chloropropene and hydrogen peroxide generate epichlorohydrin and water, with high atom utilization and little pollution. Carrying out the continuous oxidation reaction in the continuous reactor can increase the reaction efficiency, which is beneficial to industrial mass production.

In a preferred embodiment, in the above-mentioned continuous synthesis method, the catalyst can be pre-loaded into the loop reactor. By pre-packing the catalyst, the packing quality of the catalyst can be ensured, the catalyst can be fixed in the loop reactor, the mechanical strength can be increased, the catalyst can be prevented from dispersing freely in the reaction liquid, and the service life of the catalyst can be increased.

In a preferred embodiment, in the above-mentioned continuous synthesis method, chloropropene and methanol are formed in a methanol/chloropropene mixing device to form a chloropropene methanol mixture, which is pumped into the loop reactor by a metering pump A.

In a preferred embodiment, in the above-mentioned continuous synthesis process, hydrogen peroxide, methanol, allyl chloride and a catalyst are put into a loop reactor to carry out epoxidation reaction, the catalyst is preloaded into the loop reactor, and the allyl chloride and Methanol is formed in the methanol/chloropropene mixing equipment to form a mixture of chloropropene and methanol, which is pumped into the loop reactor by the metering pump A, and the hydrogen peroxide is pumped into the loop reactor by the metering pump B at the same time.

The loop reactor needs to wash and activate the catalyst before use. The specific operation is: after the catalyst is filled in the reactor and the reactor is installed, the whole loop reactor is filled with deionized water by pumping, and the circulating water bath is turned on. , turn on the forced circulation pump, continue to inject deionized water into the reactor through the metering pump, wash and wet the catalyst, drain the deionized water after a certain period of time, continue to inject methanol into the reactor through the metering pump to wet the activation catalyst, and exhaust the methanol, The washing and activation of the catalyst is completed.

In a preferred embodiment, the catalyst used in the above continuous synthesis method is a TS-1 catalyst.

In a preferred embodiment, the TS-1 catalyst packed in the loop reactor in the above-mentioned continuous synthesis method can be one-stage or multi-stage.

TS-1 catalyst is a titanium-silicon molecular sieve. The four-coordinated titanium atom in its framework is the active center of catalytic oxidation reaction. TS-1 has unique catalytic effect on the shape-selective oxidation reaction of various organic compounds with hydrogen peroxide performance. By adjusting the number of filling stages of the catalyst in the loop reactor and adjusting the amount of catalyst, the amount of catalyst can be flexibly adjusted according to the reaction raw materials, reaction temperature and other conditions, so as to prevent the reaction efficiency caused by too little catalyst, and the catalyst caused by too much catalyst. waste and increased costs.

In a preferred embodiment, the loop reactor used in the above-mentioned continuous synthesis method is also connected to other components, and the other components may include a forced circulation pump, a mixer, a sedimentation tank or a centrifugal device, a production valve and a reaction liquid collection device , the loop reactor and other components together constitute a continuous synthesis device.

The forced circulation pump can be located inside the loop reactor to ensure that the catalyst is evenly mixed with the chloropropene methanol mixture and hydrogen peroxide; the mixer can be located between the metering pump and the inlet of the loop reactor to mix the chloropropene methanol mixture and hydrogen peroxide. Mixing, because allyl chloride is soluble in methanol but insoluble in water, if the proportion of methanol in the reaction system is relatively high, a homogeneous and mutually soluble reaction system can be formed after mixing. Emulsification and delamination. In the traditional fixed-bed continuous reaction, if the reaction liquid does not form a homogeneous phase, the yield will be reduced; but in the above-mentioned continuous synthesis method, the heterogeneous reaction system can also carry out a relatively complete reaction, which greatly reduces the reaction requirements. The amount of methanol; the sedimentation tank or centrifugal equipment are common or uncommon equipment for sedimentation or centrifugation, located between the mixer and the inlet of the loop reactor, connected in series or in parallel with one or more stages to prevent the reaction The mechanical impurities or particles in the system enter the loop reactor, destroying the catalyst and the reaction device; by setting the extraction valve, it is convenient to take samples to monitor the progress of the reaction in real time; after the reaction is completed, the reaction liquid after the reaction is transferred to the reaction Liquid collection equipment for centralized follow-up processing.

In a preferred embodiment, the outlet of the loop reactor can be connected to a filter. A filter is connected to the loop reactor outlet to prevent the passage of catalyst solid particle residues with the smallest particle size, resulting in catalyst loss.

In a preferred embodiment, the above-mentioned filter can be a ceramic filter or a filter of other materials, such as a tetrafluoro filter, the pore size of the filter used is smaller than the catalyst solid particle residue with the smallest particle size, and can The reaction solution can be tolerated.

In a preferred embodiment, the molar ratio of propene chloride and hydrogen peroxide used in the continuous synthesis method may be 1-4:1.

In a preferred embodiment, the molar ratio of methanol and hydrogen peroxide used in the continuous synthesis method may be 1 to 5:1.

In a preferred embodiment, the concentration of hydrogen peroxide used in the above-mentioned continuous synthesis method may be 10-70 wt %.

In a preferred embodiment, the reaction temperature of the above-mentioned continuous synthesis method is 0-80°C. A jacket temperature control system can be set up in the loop reactor, and the reaction temperature can be controlled by using circulating water.

In a preferred embodiment, using the above-mentioned continuous synthesis method, the residence time of the reactants in the loop reactor can be 0.1-10 h.

In a preferred embodiment, using the above-mentioned continuous synthesis method, the reaction pressure can be 0.1-1 MPa.

By adjusting the above-mentioned feed ratio, reaction temperature, reaction pressure, reaction time and other conditions, different reaction conditions can be flexibly adjusted according to the change of reaction raw materials, all of which can achieve the expected effect of continuous reaction to efficiently prepare epichlorohydrin, satisfying Production requirements.

In the second typical embodiment of the present application, a continuous reaction device is provided, and the continuous reaction device includes: a hydrogen peroxide supply device 2, a methanol/chloropropene mixing device 1, and a ring for realizing the continuous reaction. Type reactor 11, the loop reactor is communicated with hydrogen peroxide supply equipment and methanol/chloropropene mixing equipment. The methanol/chloropropene mixing device can be a mixing tank, and the hydrogen peroxide supply device can be a hydrogen peroxide tank.

In a preferred embodiment, the continuous reaction device further includes a heating device arranged along the circumference of the outer wall of the loop reactor. In a preferred embodiment, the heating device includes a heating jacket. The heating device can also be other types of heating equipment, which are arranged in the loop reactor or the connecting pipeline or other positions of the continuous reaction device, so as to facilitate precise adjustment and control of the reaction temperature, so that the reaction can be carried out at a suitable temperature.

In a preferred embodiment, the loop reactor includes: a curved reaction tube section, the curved reaction tube section includes a plurality of U-shaped connected reaction tubes; a straight tube section: communicated with the ends of the U-shaped reaction tubes at both ends of the curved reaction tube section; and The forced circulation pump 5 is arranged on the reaction pipeline of the straight pipe section. The forced circulation pump can be located inside the loop reactor to ensure that the catalyst is evenly mixed with the mixture of chloropropene methanol and hydrogen peroxide. Both curved reaction tubes and straight tubes can be 1, 2, 3 or more pipes can be added according to actual production needs to meet production needs.

In a preferred embodiment, the continuous reaction device further comprises a mixer 9, and the mixer is arranged on the pipeline connecting the hydrogen peroxide supply equipment and the methanol/chloropropene mixing equipment with the loop reactor, and the mixer can also be located at the metering pump Between the inlet of the loop reactor and the inlet of the loop reactor, it is used to mix the mixture of chloropropene methanol and hydrogen peroxide evenly.

In a preferred embodiment, the continuous reaction device further comprises a settling tank or a centrifugal device 10, and the settling tank or the centrifugal device is arranged on the pipeline connecting the hydrogen peroxide supply device and the methanol/chloropropene mixing device with the loop reactor, and between the mixer and the loop reactor. Settling tank or centrifugal equipment are common or uncommon equipment for settling or centrifugation, located between the mixer and the inlet of the loop reactor, connected in series or in parallel with one or more stages, preventing mechanical Impurities or particles enter the loop reactor, destroying the catalyst and the reaction unit.

In a preferred embodiment, the continuous reaction device further includes a metering pump A 3 and a metering pump B 4, the metering pump A is arranged on the pipeline between the methanol/chloropropene mixing equipment and the mixer, and the metering pump B is arranged on the On the pipeline between the hydrogen peroxide supply equipment and the mixer. Using the metering pump to quantitatively transport the reaction raw materials, the injection ratio can be flexibly controlled to achieve a better reaction effect.

In a preferred embodiment, the continuous reaction device further comprises a reaction liquid collecting device 6, and the reaction liquid collecting device is communicated with the outlet of the loop reactor. The reaction liquid collection device may be a reaction liquid collection tank, which is used to collect the reaction liquid after the reaction is completed, so as to facilitate the subsequent processing of the reaction liquid after the reaction is completed.

In a preferred embodiment, the continuous reaction device further includes a draw valve 8, and the draw valve is located on the pipeline connecting the reaction liquid collecting device and the outlet of the loop reactor. By setting the extraction valve, it is convenient to take samples to monitor the progress of the reaction in real time.

In a preferred embodiment, the continuous reaction device further comprises a filter 7, and the filter is arranged on the outlet of the loop reactor. Used to prevent the passage of catalyst solid particle residues with the smallest particle size, resulting in catalyst loss.

In a preferred embodiment, the loop reactor further includes a catalyst, and the catalyst is pre-packed in the curved pipe section and the straight pipe section.

In a preferred embodiment, the catalyst is packed in one or more stages. By adjusting the number of filling stages of the catalyst in the loop reactor and adjusting the amount of catalyst, the amount of catalyst can be flexibly adjusted according to the reaction raw materials, reaction temperature and other conditions, so as to prevent the reaction efficiency caused by too little catalyst, and the catalyst caused by too much catalyst. waste and increased costs. By pre-packing the catalyst, the packing quality of the catalyst can be ensured, the catalyst can be fixed in the loop reactor, the mechanical strength can be increased, the catalyst can be prevented from being freely dispersed in the reaction liquid, and the service life of the catalyst can be increased. The four-stage packing of the catalysts I-stage 12, II-stage catalyst 13, III-stage catalyst 14, and IV-stage catalyst 15 can flexibly adjust the amount of catalyst required to meet the different needs of different conditions in production.

In a preferred embodiment, the filter is a ceramic filter. The filter may also be a filter of other materials, and the filter pore size used is smaller than the catalyst solid particle residue with the smallest particle size and can withstand the reaction liquid.

Using the continuous reaction device, continuous reaction can be carried out, including the continuous synthesis process of the above-mentioned epichlorohydrin.

The beneficial effects of the present application will be further explained in detail below with reference to specific embodiments.

Example 1:

(1) Fill No. TS-1 catalyst into the loop reactor shown in Figure 1, fill I-III sections, install the reactor, pump deionized water to fill the entire loop reactor, open the circulating water bath, When the water temperature is 0°C, turn on the forced circulation pump. Continue to inject deionized water into the system through the metering pump for 4h to wash the wetting catalyst and drain the deionized water; continue to inject methanol into the system through the metering pump for 4h to wet the activated catalyst and drain the methanol;

(2) Allyl chloride and methanol are uniformly mixed according to the molar ratio of 1:1;

(3) simultaneously open metering pump A, B, feed to mixer, control chloropropene and hydrogen peroxide mol ratio 1:1, hydrogen peroxide concentration is 50wt%, the residence time of control reactant in loop reactor is 2h, reaction pressure is 0.1Mpa;

(4) Measure the hydrogen peroxide and gas spectrum of the produced material every 30min until the content of epichlorohydrin in the produced oil layer and water layer reaches a stable value. Start stable operation to realize the continuous synthesis of the reaction;

(5) continuous operation under the above-mentioned conditions, during the operation, the composition of the reaction mixture output in the detection reactor is detected, and the conversion rate of oxidant (hydrogen peroxide), the selectivity of epichlorohydrin (that is, the conversion rate of hydrogen peroxide is calculated according to the conversion rate of hydrogen peroxide) Chloropropane yield), wherein the continuous operation result data are listed in Table 1.

Example 2:

(1) Fill No. TS-1 catalyst in the loop reactor shown in Figure 1, fill 1 section, install the reactor, pump deionized water to fill the entire loop reactor, open the circulating water bath, and the water temperature is 10 ℃, turn on the forced circulation pump. Continue to inject deionized water into the system through the metering pump for 6 hours to wash the wetting catalyst and drain the deionized water; continue to inject methanol into the system through the metering pump for 8 hours to wet the activated catalyst and drain the methanol;

(2) Allyl chloride and methanol are uniformly mixed according to a molar ratio of 1:2;

(3) simultaneously open metering pump A, B, feed to mixer, control chloropropene and hydrogen peroxide mol ratio 1:1, hydrogen peroxide concentration is 10wt%, the residence time of control reactant in loop reactor is 1h, reaction pressure is 1Mpa;

(4) with embodiment 1;

(5) Same as Example 1.

Example 3:

(1) Fill No. TS-1 catalyst in the loop reactor shown in Figure 1, fill I-IV section, install the reactor, pump deionized water to fill the entire loop reactor, open the circulating water bath, When the water temperature is 30°C, turn on the forced circulation pump. Continue to inject deionized water into the system through the metering pump for 8h to wash the wetting catalyst and drain the deionized water; continue to inject methanol into the system through the metering pump for 6h to wet the activated catalyst and drain the methanol;

(3) simultaneously open metering pump A, B, feed to mixer, control chloropropene and hydrogen peroxide mol ratio 3:1, hydrogen peroxide concentration is 70wt%, the residence time of control reactant in loop reactor is 0.1h, reaction The pressure is 0.5Mpa;

(4) with embodiment 1;

(5) Same as Example 1.

Example 4:

(1) Fill No. TS-1 catalyst into the loop reactor shown in Figure 1, fill I-II sections, install the reactor, pump deionized water to fill the entire loop reactor, open the circulating water bath, When the water temperature is 80°C, the forced circulation pump is turned on. Continue to inject deionized water into the system through the metering pump for 10h to wash the wetting catalyst and drain the deionized water; continue to inject methanol into the system through the metering pump for 24h to wet the activated catalyst and drain the methanol;

(2) Allyl chloride and methanol are uniformly mixed according to a molar ratio of 5:1;

(3) simultaneously open metering pump A, B, feed to mixer, control chloropropene and hydrogen peroxide mol ratio 5:1, hydrogen peroxide concentration is 70wt%, the residence time of control reactant in loop reactor is 10h, reaction pressure is 0.7Mpa;

(4) with embodiment 1;

(5) Same as Example 1.

Example 5:

(1) Fill No. TS-1 catalyst in the loop reactor shown in Figure 1, fill I-IV section, install the reactor, pump deionized water to fill the entire loop reactor, open the circulating water bath, When the water temperature is 20°C, the forced circulation pump is turned on. Continue to inject deionized water into the system through the metering pump for 10h to wash the wetting catalyst and drain the deionized water; continue to inject methanol into the system through the metering pump for 12h to wet the activated catalyst and drain the methanol;

(2) Allyl chloride and methanol are uniformly mixed according to a molar ratio of 4:3;

(3) simultaneously open metering pump A, B, feed to mixer, control chloropropene and hydrogen peroxide mol ratio 4:1, hydrogen peroxide concentration is 40wt%, the residence time of control reactant in loop reactor is 3h, reaction pressure is 0.3Mpa;

(4) with embodiment 1;

(5) Same as Example 1.

Example 6:

(1) Fill No. TS-1 catalyst in the loop reactor shown in Figure 1, fill I-IV section, install the reactor, pump deionized water to fill the entire loop reactor, open the circulating water bath, When the water temperature is 10°C, the forced circulation pump is turned on. Continue to inject deionized water into the system through the metering pump for 12h to wash the wetting catalyst and drain the deionized water; continue to inject methanol into the system through the metering pump for 16h to wet the activated catalyst and drain the methanol;

(2) Allyl chloride and methanol are uniformly mixed according to a molar ratio of 3:5;

(3) simultaneously open metering pump A, B, feed to mixer, control chloropropene and hydrogen peroxide mol ratio 3:1, hydrogen peroxide concentration is 60wt%, the residence time of control reactant in loop reactor is 1h, reaction pressure is 0.1Mpa;

(4) with embodiment 1;

(5) Same as Example 1.

Table 1: Example 1-6 continuous running result data

Example 7:

The reaction conditions are the same as in Example 1, and the only difference is that the molar ratio of allyl chloride and hydrogen peroxide is 1:2, and the continuous operation result data is listed in Table 2.

Example 8:

The reaction conditions are the same as those in Example 1, and the only difference is that allyl chloride and methanol are in a molar ratio of 2:1, and the continuous operation result data are listed in Table 2.

Example 9:

The reaction conditions are the same as those in Example 1, the only difference is that the concentration of hydrogen peroxide is 5 wt %, and the data of the continuous operation results are listed in Table 2.

Example 10:

The reaction conditions are the same as those in Example 1, the only difference is that the reaction temperature is 100° C., and the data of the continuous operation results are listed in Table 2.

Example 11:

The reaction conditions are the same as those in Example 1, the only difference is that the reaction pressure is 2 MPa, and the data of the continuous operation results are listed in Table 2.

Table 2: Example 7-11 continuous running result data

Comparative Example 1:

(1) add allyl chloride, methanol, hydrogen peroxide and catalyzer in the same proportion as in Example 5, be warming up to 42 ℃, react 2h, and the reaction pressure is 0.1Mpa;

(2) reaction finishes, detects the hydrogen peroxide residue and epichlorohydrin content of reaction solution, calculates the hydrogen peroxide conversion rate and the yield of epichlorohydrin. The catalyst is filtered and used for the next batch of epoxidation reaction;

The results are listed in Table 3.

Comparative Example 2:

Use a traditional fixed-bed continuous reactor for the reaction, mix allyl chloride, hydrogen peroxide, and methanol in a molar ratio of 3:1:10 to form a homogeneous phase (the hydrogen peroxide concentration is 70 wt%), then send it to a traditional fixed-bed continuous reactor to control the reaction The temperature is 30°C, the residence time of the reactants in the fixed-bed continuous reactor is 0.1h, and the reaction pressure is 0.5MPa. Continuous operation under the above conditions, during the operation, the composition of the output reaction mixture in the fixed-bed continuous reactor is detected, and the conversion rate of the oxidant (hydrogen peroxide) and the selectivity of epichlorohydrin (that is, the epoxy Chloropropane yield), wherein, the continuous operation result data are listed in Table 3.

Comparative Example 3:

Use a traditional fixed-bed continuous reactor for the reaction, and mix allyl chloride, hydrogen peroxide, and methanol in a molar ratio of 3:1:3 (due to the low ratio of methanol, it is in an emulsified state after mixing and cannot form a homogeneous phase; the concentration of hydrogen peroxide is 70wt%) , sent to the traditional fixed-bed continuous reactor, the reaction temperature was controlled to 30 °C, the residence time of the reactants in the fixed-bed continuous reactor was 0.1 h, and the reaction pressure was 0.5 MPa. Continuous operation under the above conditions, during the operation, the composition of the output reaction mixture in the fixed-bed continuous reactor is detected, and the conversion rate of the oxidant (hydrogen peroxide) and the selectivity of epichlorohydrin (that is, the epoxy Chloropropane yield), wherein, the continuous operation result data are listed in Table 3.

Table 3: Result data of comparative catalyst application:

From the above description, it can be seen that the above-mentioned embodiments of the present invention have achieved the following technical effects: utilizing the continuous synthesis method of above-mentioned epichlorohydrin, the catalyst has a long service life, and can obtain relatively stable hydrogen peroxide conversion and higher Therefore, a series of protection schemes of the present application are proposed.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

A continuous synthesis process of epichlorohydrin is characterized in that the reactant and the catalyst are continuously epoxidized in a loop reactor, and the reactant includes hydrogen peroxide, methanol and chloropropene.
The continuous synthesis process according to claim 1, wherein the catalyst is preloaded into the loop reactor.
The continuous synthesis process according to claim 2, wherein the chloropropene and the methanol form a chloropropene-methanol mixed solution in a methanol/chloropropene mixing device, which is pumped into the ring reaction by a metering pump A device.
The continuous synthesis process according to claim 3, wherein the hydrogen peroxide, the methanol, the propene chloride and the catalyst are put into the loop reactor to carry out epoxidation reaction, the The catalyst is pre-loaded into the loop reactor, and the chloropropene and the methanol are formed in the methanol/chloropropene mixing device to form a chloropropene methanol mixture that is pumped into the loop reactor by the metering pump A At the same time, the hydrogen peroxide is pumped into the loop reactor by the metering pump B.
The continuous synthesis process according to claim 4, wherein the catalyst is a TS-1 catalyst.
The continuous synthesis process according to claim 5, wherein the catalyst is packed in one stage or more.
The continuous synthesis process according to claim 4, wherein the loop reactor is further connected with other components, and the other components include a forced circulation pump, a mixer, a sedimentation tank or a centrifugal device, a production valve, a reaction Liquid collection equipment.
The continuous synthesis process according to claim 7, wherein the outlet of the loop reactor is further connected to a filter.
The continuous chemical synthesis process according to claim 8, wherein the filter is a ceramic filter.
The continuous synthesis process according to any one of claims 1 to 9, wherein the molar ratio of the allyl chloride to hydrogen peroxide is 1-4:1.
The continuous synthesis process according to any one of claims 1 to 9, wherein the methanol and hydrogen peroxide mol ratio is 1-5:1.
The continuous synthesis process according to any one of claims 1 to 9, wherein the concentration of the hydrogen peroxide is 10-70%.
The continuous synthesis process according to any one of claims 1 to 9, wherein the reaction temperature is 0-80°C.
The continuous synthesis process according to any one of claims 1 to 9, wherein the residence time of the reactants in the loop reactor is 0.1-10 h.
The continuous synthesis process according to any one of claims 1 to 9, wherein the reaction pressure is 0.1-1 MPa.
A continuous reaction device, characterized in that the continuous reaction device comprises:

Hydrogen peroxide supply equipment,

Methanol/Propylene Chloride Mixing Equipment, and

A loop reactor for realizing continuous reaction, the loop reactor is communicated with the hydrogen peroxide supply device and the methanol/chloropropene mixing device.
The continuous reaction device according to claim 16, characterized in that, the continuous reaction device further comprises a heating device, and the heating device is arranged along the circumference of the outer wall of the loop reactor.
The continuous reaction device according to claim 17, wherein the heating device comprises a heating jacket.
The continuous reaction device according to claim 18, wherein the loop reactor comprises:

A curved reaction tube section, the curved reaction tube section includes a plurality of U-shaped connected reaction tubes;

Straight pipe section: communicated with the ends of the U-shaped reaction tubes at both ends of the curved reaction pipe section; and

A forced circulation pump, which is arranged on the reaction pipeline of the straight pipe section.
The continuous reaction device according to claim 19, characterized in that, the continuous reaction device further comprises a mixer, and the mixer is arranged between the hydrogen peroxide supply equipment and the methanol/chloropropene mixing equipment and the on the pipeline connected to the loop reactor.
The continuous reaction device according to claim 20, characterized in that, the continuous reaction device further comprises a sedimentation tank or a centrifugal device, and the sedimentation tank or centrifugal device is provided in the hydrogen peroxide supply device and the methanol/chlorine The propylene mixing device is on the pipeline that communicates with the loop reactor, and is located between the mixer and the loop reactor.
The continuous reaction device according to claim 21, wherein the continuous reaction device further comprises a metering pump A and a metering pump B, and the metering pump A is arranged between the methanol/chloropropene mixing equipment and the On the pipeline between the mixers, the metering pump B is arranged on the pipeline between the hydrogen peroxide supply device and the mixer.
The continuous reaction device according to any one of claims 16 to 22, wherein the continuous reaction device further comprises a reaction liquid collection device, the reaction liquid collection device and the outlet of the loop reactor Connected.
The continuous reaction device according to claim 23, characterized in that, the continuous reaction device further comprises a production valve, and the production valve is located in the reaction liquid collecting device and communicates with the outlet of the loop reactor on the pipeline.
The continuous reaction device according to claim 24, characterized in that, the continuous reaction device further comprises a filter, and the filter is provided on the outlet of the loop reactor.
The continuous reaction device according to claim 25, wherein the loop reactor further comprises a catalyst, and the catalyst is pre-installed in the curved pipe section and the straight pipe section.
The continuous reaction device according to claim 26, wherein the catalyst is packed in one stage or more.
The continuous reaction device according to claim 27, wherein the filter is a ceramic filter.