Method for gas-liquid separation in ECH two-phase flow, separation system and application

Abstract

The invention discloses a gas-liquid separation method in ECH two-phase flow, a separation system and application. The ECH two-phase flow gas-liquid separation method comprises the following steps: introducing protective gas into a material extracted from a reactor I, then carrying out gas-liquid separation, and enabling a separated liquid phase to enter a reactor II for reaction; materials fed into the reactor I are raw materials for producing epoxy chloropropane; the material extracted from the reactor I is a gas-liquid two-phase flow, and the gas is oxygen. According to the method for gas-liquid separation in the ECH two-phase flow, the explosion risk in ECH production can be effectively reduced, and the method is simple and economical and has very good industrial application value.

Description

Technical Field

[0001] The present invention relates to the technical field of epichlorohydrin (ECH) production, and more particularly to a method for gas-liquid separation in an ECH two-phase flow and a separation system and application. Background Art

[0002] Epichlorohydrin (ECH), also known as 3-chloro-1,2-epoxypropane, is an organic compound with the chemical formula C 3 H 5 ClO is a colorless liquid organic compound with an odor similar to chloroform. It is mainly used as a raw material for organic synthesis, and is also used as a solvent, plasticizer, surfactant, etc.

[0003] The process of preparing epichlorohydrin by direct epoxidation of allyl chloride with hydrogen peroxide has become a research hotspot. This process avoids the generation of wastewater and is a new green, clean, and atom-economical epichlorohydrin synthesis process with good application prospects.

[0004] The process of preparing epichlorohydrin by direct epoxidation is to dissolve allyl chloride and hydrogen peroxide in a solvent, fully contact and react with a titanium silicon molecular sieve catalyst in liquid form. The solvent is usually methanol, and the role of the solvent is to dissolve and fully contact the incompatible allyl chloride and hydrogen peroxide in the solvent. The reactor of the epichlorohydrin unit mainly carries out the reaction process of producing epichlorohydrin by epoxidation of allyl chloride. The reaction is an exothermic reaction, adopts a shell-and-tube type, and uses a shell-side water bath circulation to extract heat. At present, the reactor of the epichlorohydrin unit is two in series, and the flow direction is bottom-in and top-out.

[0005] The inventors of the present invention have found that the raw materials for producing epichlorohydrin contain hydrogen peroxide. During the reaction process, a certain amount of hydrogen peroxide is decomposed into oxygen and water under the influence of temperature, resulting in the reactor's reaction discharge being a gas-liquid two-phase flow. According to safety analysis, when the bubbles in the gas-liquid two-phase are large, there is a risk of explosion, so there are requirements for the two-phase flow pattern of the pipeline, and plunger flow cannot occur. However, in actual production, it was found that no matter how the pipe diameter or pipeline layout was adjusted, the flow pattern requirements could not be met.

[0006] Therefore, there is a need for a safer method for producing epichlorohydrin. Summary of the invention

[0007] In order to solve the problems in the prior art, the present invention proposes a method for gas-liquid separation in ECH two-phase flow and a separation system and application. The present invention adds a gas-liquid separation device between two reactors connected in series to separate the gas phase, and at the same time, a protective gas (such as nitrogen) is introduced into the discharge pipe of reactor one to reduce the oxygen content in the gas phase. Under this ratio, the gas phase oxygen content in the pipeline can be guaranteed to be lower than the limiting oxygen content of the material system, which is in a safe range and reduces the risk of explosion; at the same time, the introduction of nitrogen increases the gas in the discharge of reactor one, and the bubbles become larger. When separated in the gas-liquid separation device, it is more conducive to the separation of oxygen from the liquid phase, enhances the separation effect of oxygen, reduces the oxygen in the feed of reactor two, and reduces the risk of explosion. It can be seen that the method for gas-liquid separation in the ECH two-phase flow of the present invention can effectively reduce the risk of explosion in ECH production, and the method of the present invention is simple, economical, and has very good industrial application value.

[0008] One of the objects of the present invention is to provide a method for gas-liquid separation of ECH two-phase flow, comprising the following steps:

[0009] A protective gas is introduced into the material extracted from the reactor one, and then a gas-liquid separation is performed, and the separated liquid phase enters the reactor two for reaction; the material feed of the reactor one is a raw material for producing epichlorohydrin; the material extracted from the reactor one is a gas-liquid two-phase flow, in which the gas is oxygen.

[0010] In the technical solution of the present invention, the protective gas is selected from at least one of an inert gas and nitrogen, preferably nitrogen.

[0011] In the ECH two-phase flow gas-liquid separation method of the present invention, preferably,

[0012] The volume ratio of the protective gas to the gaseous oxygen in the material extracted from the reactor 1 is 10 to 40:1.

[0013] In the ECH two-phase flow gas-liquid separation method of the present invention, preferably,

[0014] The volume ratio of the protective gas to the gaseous oxygen in the material extracted from the reactor 1 is 20 to 40:1.

[0015] In the ECH two-phase flow gas-liquid separation method of the present invention, preferably,

[0016] The material feed of the reactor 1 at least includes hydrogen peroxide, preferably methanol, allyl chloride, and hydrogen peroxide; more preferably, the concentration of hydrogen peroxide is 2-8 wt%; and / or,

[0017] In the technical solution of the present invention, the operating conditions of the reactor one all adopt the existing conventional operating conditions. Preferably, the volume ratio of liquid to gas in the material extracted from the reactor one is 8-20:1.

[0018] In the ECH two-phase flow gas-liquid separation method of the present invention, preferably,

[0019] The feed of the reactor 1 comprises methanol, allyl chloride and hydrogen peroxide; preferably, the concentration of hydrogen peroxide is 2-8 wt%.

[0020] In the technical scheme of the present invention, the reaction of generating epichlorohydrin occurs in both reactor 1 and reactor 2, wherein the raw materials in reactor 1 will not react completely, and most of them will react with allyl chloride to generate epichlorohydrin, so they will enter reactor 2 to react completely again, but there is still a small amount of hydrogen peroxide in the discharge of reactor 1, which will ineffectively decompose to produce water and oxygen. The inventors found that when hydrogen peroxide decomposes more ineffectively, when the decomposition product oxygen forms a separate gas phase space in the pipeline, there is a potential risk of explosion. The present invention introduces nitrogen into the discharge of reactor 1 to reduce the oxygen content in the gas phase. Under this ratio, it can be ensured that the oxygen content in the gas phase in the pipeline is lower than the limiting oxygen content of the material system, within a safe range, and reduce the risk of explosion; at the same time, the introduction of nitrogen increases the gas in the discharge of reactor 1, and the bubbles become larger. When separated in the gas-liquid separation device, it is more conducive to separating oxygen from the liquid phase, and enhancing the separation effect of oxygen.

[0021] In the ECH two-phase flow gas-liquid separation method of the present invention, preferably,

[0022] The feed of the reactor 2 includes methanol, allyl chloride, hydrogen peroxide, epichlorohydrin and unseparated gas; the unseparated gas includes oxygen and protective gas;

[0023] Preferably, the two-phase flow pattern in the feed of reactor 2 is bubble flow. In the technical solution of the present invention, the feed of reactor 2 is mainly liquid phase material, containing only a small amount of small bubbles. Here, the oxygen content in the feed of reactor 2 is low, which effectively reduces the risk of explosion.

[0024] In the ECH two-phase flow gas-liquid separation method of the present invention, preferably,

[0025] In the technical solution of the present invention, the operating conditions of the gas-liquid separation device all adopt existing conventional operating conditions. Preferably, the content of unseparated gas in the feed of the reactor 2 (i.e., the liquid phase material extracted from the gas-liquid separation device) is 0-0.04wt%. At this content, the content of gas (especially oxygen) in the feed of the reactor 2 is already very small, and the risk of explosion is very low.

[0026] In the technical solution of the present invention, the operating conditions of the reactor 2 also adopt the existing conventional operating conditions.

[0027] The second object of the present invention is to provide a system for gas-liquid separation of ECH two-phase flow, the system comprising a reactor 1, a gas-liquid separation device, and a reactor 2 connected in sequence; a nitrogen feed pipeline is also provided on the connecting pipeline between the reactor 1 and the gas-liquid separation device; a gas phase outlet pipeline is also provided above the gas-liquid separation tank; a pressure control device is provided between the nitrogen feed pipeline and the gas phase outlet pipeline of the gas-liquid separation device;

[0028] Preferably, the method for gas-liquid separation of ECH two-phase flow as described in any one of the objects of the present invention adopts the system.

[0029] In the ECH two-phase flow gas-liquid separation system of the present invention, preferably,

[0030] In the technical solution of the present invention, in order to ensure that the gaseous oxygen in each part of the reactor system is small bubbles or below the limit oxygen content, the nitrogen feed pipeline should be as close to the outlet of the reactor as possible, and it is most preferred that the nitrogen feed pipeline is seamlessly connected to the outlet of the reactor; and / or,

[0031] The gas phase outlet pipeline is located at the top of the gas-liquid separation device; and / or,

[0032] The material flow direction in the reactor 1 and the reactor 2 is bottom-in and top-out.

[0033] In the technical solution of the present invention, the pressure control device controls the pressure of the gas-liquid separation device and related pipelines by controlling the exhaust volume of the gas phase outlet pipeline of the gas-liquid separation device. Since there is a certain distance between the nitrogen feed pipeline and the gas-liquid separation device, there is a little pressure drop during the material transportation process, so the pressure of the nitrogen feed is slightly higher than the pressure in the gas-liquid separation device, which can make it easier for the nitrogen feed to enter the gas-liquid separation device; at the same time, the pressure in the gas-liquid separation device is controlled to be higher than the pressure of the reactor 2, so that it can be ensured that the gas-liquid separation device can enter the reactor 2 through the differential pressure.

[0034] In the ECH two-phase flow gas-liquid separation system of the present invention, preferably,

[0035] The gas-liquid separation device is a vertical gas-liquid separator;

[0036] Preferably,

[0037] The material entering the gas-liquid separation device is fed in a tangential feeding manner; and / or,

[0038] A defoaming net is arranged on the top of the gas-liquid separation device.

[0039] In the technical solution of the present invention, the gas-liquid separation device can effectively separate nitrogen and oxygen from the liquid phase, so that the feed of reactor two contains only a small amount of oxygen and protective gas. At this time, it can effectively avoid the formation of plunger flow in the feed of reactor two, which causes a short circuit inside the shell-and-tube reactor, which is beneficial to improving safety and increasing the life of the catalyst.

[0040] In the technical solution of the present invention, a defoaming net is arranged on the top of the gas-liquid separation device, which can intercept small droplets brought out by the gas phase during gas-liquid separation and prevent a small amount of droplets from being brought into the gas phase discharge pipeline.

[0041] In the technical solution of the present invention, in order to improve the gas-liquid separation effect, tangential feeding is adopted. Tangential feeding utilizes the initial velocity of the material entering the tank to make the material rotate along the inner wall of the tank, which is beneficial to gas-liquid separation.

[0042] The third object of the present invention is to provide a method for gas-liquid separation of ECH two-phase flow as described in any one of the objects of the present invention or an application of the system for gas-liquid separation of ECH two-phase flow as described in the second object of the present invention in the production of epichlorohydrin.

[0043] The endpoints and any values ​​of the scope disclosed in the present invention are not limited to the precise scope or value, and these scopes or values ​​should be understood to include values ​​close to these scopes or values. For numerical ranges, the endpoint values ​​of each scope, the endpoint values ​​of each scope and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be regarded as specifically disclosed in this article. Hereinafter, in principle, each technical solution can be combined with each other to obtain a new technical solution, which should also be regarded as specifically disclosed in this article.

[0044] Compared with the prior art, the present invention has at least the following advantages:

[0045] The method for gas-liquid separation in ECH two-phase flow of the present invention can effectively reduce the explosion risk in ECH production, and the method of the present invention is simple, economical and has very good industrial application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a schematic diagram of the system for gas-liquid separation of ECH two-phase flow of the present invention;

[0047] Figure 2 It is a schematic diagram of tangential feeding of the gas-liquid separation device of the present invention.

[0048] Description of reference numerals:

[0049] 1-reactor 1, 2-gas-liquid separation device, 3-reactor 2; PC-pressure control device; 2-1-feeding port of gas-liquid separation device;

[0050] 101-material feed of reactor 1;

[0051] 102-protective gas;

[0052] 103- a mixture of protective gas and materials extracted from reactor 1;

[0053] 104-liquid phase material;

[0054] 105-gas phase material;

[0055] 106-material extracted from reactor 2;

[0056] Figure 1 In the process, the material feed 101 of reactor one enters reactor one 1 for reaction, a protective gas 102 is introduced into the material produced from reactor one, and a mixture 103 of the formed protective gas and the material produced from reactor one is introduced into a gas-liquid separation device 2 for gas-liquid separation, and the separated liquid phase material 104 enters reactor two 3 for reaction; after the reaction, the material 106 produced from reactor two is sent out of the system or subjected to other post-processing; the gas phase material 105 separated in the pressure gas-liquid separation device 2 is discharged through the gas phase outlet pipe of the gas-liquid separation device; in addition, a pressure control device PC is provided between the nitrogen feed pipeline and the gas phase outlet pipe of the gas-liquid separation device; the pressure control device PC controls the pressure of the gas-liquid separation device and related pipelines by controlling the exhaust volume of the gas phase outlet pipe of the gas-liquid separation device. DETAILED DESCRIPTION

[0057] The present invention is described in detail below in conjunction with specific drawings and embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by those skilled in the art based on the content of the present invention still fall within the scope of protection of the present invention.

[0058] It should also be noted that the various specific technical features described in the following specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0059] In addition, the various embodiments of the present invention may be arbitrarily combined as long as they do not violate the concept of the present invention. The technical solutions thus formed belong to part of the original disclosure of this specification and also fall within the protection scope of the present invention.

[0060] The raw materials used in the examples and comparative examples, unless otherwise specified, are disclosed in the prior art, for example, they can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0061] Example 1

[0062] like Figure 1 As shown, a system for gas-liquid separation of an ECH two-phase flow of the present invention is provided, the system comprises a reactor 1, a gas-liquid separation device 2, and a reactor 3 connected in sequence; a nitrogen feed pipeline is also provided on the connecting pipeline between the reactor 1 and the gas-liquid separation device; a gas phase outlet pipeline is also provided above the gas-liquid separation tank; a pressure control device PC is provided between the nitrogen feed pipeline and the gas phase outlet pipeline of the gas-liquid separation device;

[0063] Among them, the nitrogen feed pipeline is seamlessly connected to the discharge port of reactor 1; the gas phase outlet pipeline is located at the top of the gas-liquid separation device; the material flow direction in reactor 1 and reactor 2 is bottom-in and top-out.

[0064] The gas-liquid separation device is a vertical gas-liquid separator; the material entering the gas-liquid separation device is fed in a tangential feeding manner, wherein the feed port 2-1 of the gas-liquid separation device is located in the gas-liquid separation device as shown in FIG. Figure 2 As shown, a defoaming net is also provided on the top of the gas-liquid separation device.

[0065] Figure 1 In the process, the material feed 101 of reactor one enters reactor one 1 for reaction, a protective gas 102 is introduced into the material produced from reactor one, and a mixture 103 of the formed protective gas and the material produced from reactor one is introduced into a gas-liquid separation device 2 for gas-liquid separation, and the separated liquid phase material 104 enters reactor two 3 for reaction; after the reaction, the material 106 produced from reactor two is sent out of the system or subjected to other post-processing; the gas phase material 105 separated in the pressure gas-liquid separation device 2 is discharged through the gas phase outlet pipe of the gas-liquid separation device; in addition, a pressure control device PC is provided between the nitrogen feed pipeline and the gas phase outlet pipe of the gas-liquid separation device; the pressure control device PC controls the pressure of the gas-liquid separation device and related pipelines by controlling the exhaust volume of the gas phase outlet pipe of the gas-liquid separation device.

[0066] Example 2

[0067] A method for gas-liquid separation of ECH two-phase flow, using Figure 1 The ECH two-phase flow gas-liquid separation system shown includes the following steps:

[0068] A protective gas is introduced into the material extracted from the reactor one, wherein the material feed of the reactor one is a raw material for producing epichlorohydrin, including methanol, allyl chloride, and hydrogen peroxide; the concentration of hydrogen peroxide is 8wt%; the material extracted from the reactor one is a gas-liquid two-phase flow, in which the gas is oxygen; the volume ratio of liquid to oxygen in the material extracted from the reactor one is 8:1; the protective gas is selected from nitrogen, and the volume ratio of the protective gas to the gaseous oxygen in the material extracted from the reactor one is 40:1; then the mixture of the protective gas and the material extracted from the reactor one is sent to a gas-liquid separation device for gas-liquid separation, and the separated liquid phase enters the reactor two for reaction;

[0069] The feed of the reactor 2 (i.e. the liquid phase material separated by the gas-liquid separation device) includes methanol, allyl chloride, hydrogen peroxide, epichlorohydrin and unseparated gas; the unseparated gas includes oxygen and nitrogen; the two-phase flow pattern in the feed of the reactor 2 is bubble flow; the content of unseparated gas in the feed of the reactor 2 is 0.04wt%.

[0070] Through the above method, it can be seen that the present invention introduces nitrogen into the discharge of reactor one to reduce the oxygen content in the gas phase. Under this ratio, it can be ensured that the oxygen content of the gas phase in the pipeline is lower than the limit oxygen content of the material system, which is within a safe range and reduces the risk of explosion. In addition, the gas-liquid separation device added by the present invention can discharge most of the gas in the pipeline, leaving only a small amount of gas, which is not enough to form large bubbles and has no risk of explosion.

[0071] Example 3

[0072] A method for gas-liquid separation of ECH two-phase flow, using Figure 1 The ECH two-phase flow gas-liquid separation system shown includes the following steps:

[0073] A protective gas is introduced into the material extracted from the reactor one, wherein the material feed of the reactor one is a raw material for producing epichlorohydrin, including methanol, allyl chloride, and hydrogen peroxide; the concentration of hydrogen peroxide is 8wt%; the material extracted from the reactor one is a gas-liquid two-phase flow, in which the gas is oxygen; the volume ratio of liquid to oxygen in the material extracted from the reactor one is 8:1; the protective gas is selected from nitrogen, and the volume ratio of the protective gas to the gaseous oxygen in the material extracted from the reactor one is 20:1; then the mixture of the protective gas and the material extracted from the reactor one is sent to a gas-liquid separation device for gas-liquid separation, and the separated liquid phase enters the reactor two for reaction;

[0074] The feed of the reactor 2 (i.e. the liquid phase material separated by the gas-liquid separation device) includes methanol, allyl chloride, hydrogen peroxide, epichlorohydrin and unseparated gas; the unseparated gas includes oxygen and nitrogen; the two-phase flow pattern in the feed of the reactor 2 is bubble flow; the content of unseparated gas in the feed of the reactor 2 is 0.01wt%.

[0075] Through the above method, it can be seen that the present invention introduces nitrogen into the discharge of reactor one to reduce the oxygen content in the gas phase. Under this ratio, it can be ensured that the oxygen content of the gas phase in the pipeline is lower than the limit oxygen content of the material system, which is within a safe range and reduces the risk of explosion. In addition, the gas-liquid separation device added by the present invention can discharge most of the gas in the pipeline, leaving only a small amount of gas, which is not enough to form large bubbles and has no risk of explosion.

[0076] Example 4

[0077] A method for gas-liquid separation of ECH two-phase flow, using Figure 1 The ECH two-phase flow gas-liquid separation system shown includes the following steps:

[0078] A protective gas is introduced into the material extracted from the reactor one, wherein the material feed of the reactor one is a raw material for producing epichlorohydrin, including methanol, allyl chloride, and hydrogen peroxide; the concentration of hydrogen peroxide is 8wt%; the material extracted from the reactor one is a gas-liquid two-phase flow, in which the gas is oxygen; the volume ratio of liquid to oxygen in the material extracted from the reactor one is 8:1; the protective gas is selected from nitrogen, and the volume ratio of the protective gas to the gaseous oxygen in the material extracted from the reactor one is 10:1; then the mixture of the protective gas and the material extracted from the reactor one is sent to a gas-liquid separation device for gas-liquid separation, and the separated liquid phase enters the reactor two for reaction;

[0079] The feed of the reactor 2 (i.e. the liquid phase material separated by the gas-liquid separation device) includes methanol, allyl chloride, hydrogen peroxide, epichlorohydrin and unseparated gas; the unseparated gas includes oxygen and nitrogen; the two-phase flow pattern in the feed of the reactor 2 is bubble flow; the content of unseparated gas in the feed of the reactor 2 is 0.001wt%.

[0080] Through the above method, it can be seen that the present invention introduces nitrogen into the discharge of reactor one to reduce the oxygen content in the gas phase. Under this ratio, it can be ensured that the oxygen content of the gas phase in the pipeline is lower than the limit oxygen content of the material system, which is within a safe range and reduces the risk of explosion. In addition, the gas-liquid separation device added by the present invention can discharge most of the gas in the pipeline, leaving only a small amount of gas, which is not enough to form large bubbles and has no risk of explosion.

[0081] Comparative Example 1

[0082] The reaction conditions are substantially the same as those in Example 2, except that no protective gas is introduced into the material extracted from the reactor 1.

[0083] In Comparative Example 1, when no nitrogen is added, the volume ratio of liquid to gas in the product of Reactor 1 is about 8:1. When the liquid flow rate is 1-2 m / s, the two-phase flow pattern in the pipeline under the corresponding pipe diameter is plug flow and if a separate gas phase space is formed in the delivery pipeline and the reactor, there is a potential risk of combustion and explosion.

[0084] Comparative Example 2

[0085] The reaction conditions are basically the same as those in Example 2, except that no protective gas is introduced into the material extracted from the reactor 1; and no gas-liquid separation device is added.

[0086] In Comparative Example 2, there is no gas-liquid separation device, and the material produced from the reactor 1 directly enters the reactor 2. In Comparative Example 2, the volume ratio of liquid to gas in the product of the reactor 1 is about 8:1. When the liquid flow rate is 1-2 m / s, the two-phase flow type in the pipeline under the corresponding pipe diameter is a plunger flow. The material produced from the reactor 1 directly enters the reactor 2, which is not conducive to its distribution in the feed area of ​​the reactor 2, and the potential risk of combustion and explosion is greater than that of Comparative Example 1.

[0087] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

[0088] All publications, patent applications, patents and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings conventionally understood by those skilled in the art. In the event of a conflict, the definition in this specification shall prevail.

[0089] When this specification uses the prefix "well-known to those skilled in the art", "prior art" or similar terms to introduce materials, substances, methods, steps, devices or components, etc., the objects introduced by the prefix cover those commonly used in the art when this application is filed, but also include those that are not commonly used at present but will become recognized in the art as being suitable for similar purposes.

[0090] In the context of the present specification, any matters or items not mentioned are directly applicable to those known in the art without any changes except those explicitly stated.

Claims

1. A method for gas-liquid separation of ECH two-phase flow, It is characterized in that The following steps are involved: A protective gas is introduced into the material extracted from the reactor one, and then a gas-liquid separation is performed, and the separated liquid phase enters the reactor two for reaction; the material feed of the reactor one is a raw material for producing epichlorohydrin; the material extracted from the reactor one is a gas-liquid two-phase flow, in which the gas is oxygen.

2. The method for gas-liquid separation of ECH two-phase flow according to claim 1, Features: The volume ratio of the protective gas to the gaseous oxygen in the material extracted from the reactor 1 is 10 to 40:

1.

3. The method for gas-liquid separation of ECH two-phase flow according to claim 2, Features: The volume ratio of the protective gas to the gaseous oxygen in the material extracted from the reactor 1 is 20 to 40:

1.

4. The method for gas-liquid separation of ECH two-phase flow according to claim 1, Features: The material feed of the reactor 1 at least includes hydrogen peroxide, preferably methanol, allyl chloride, and hydrogen peroxide; more preferably, the concentration of hydrogen peroxide is 2-8 wt%; and / or, In the material extracted from the reactor 1, the volume ratio of liquid to gas is 8-20:

1.

5. The method for gas-liquid separation of ECH two-phase flow according to claim 1, Features: The feed of the reactor 2 includes methanol, allyl chloride, hydrogen peroxide, epichlorohydrin and unseparated gas; the unseparated gas includes oxygen and / or protective gas; Preferably, the two-phase flow pattern in the feed to the second reactor is bubbling flow.

6. The method for gas-liquid separation of ECH two-phase flow according to claim 5, Features: The content of unseparated gas in the feed of the reactor 2 is 0-0.04 wt%.

7. An ECH two-phase flow gas-liquid separation system, Features: The system comprises a reactor 1, a gas-liquid separation device, and a reactor 2 which are connected in sequence; a nitrogen feed pipeline is also provided on the connecting pipeline between the reactor 1 and the gas-liquid separation device; a gas phase outlet pipeline is also provided above the gas-liquid separation tank; a pressure control device is provided between the nitrogen feed pipeline and the gas phase outlet pipeline of the gas-liquid separation device; Preferably, the method for gas-liquid separation of ECH two-phase flow described in any one of claims 1 to 6 adopts the system.

8. The ECH two-phase flow gas-liquid separation system according to claim 7, Features: The nitrogen feed pipeline is seamlessly connected to the discharge port of the reactor 1; and / or, The gas phase outlet pipeline is located at the top of the gas-liquid separation device; and / or, The material flow direction in the reactor 1 and the reactor 2 is bottom-in and top-out.

9. The ECH two-phase flow gas-liquid separation system according to claim 7, Features: The gas-liquid separation device is a vertical gas-liquid separator; Preferably, The material entering the gas-liquid separation device is fed in a tangential feeding manner; and / or, A defoaming net is arranged on the top of the gas-liquid separation device.

10. Use of the method for gas-liquid separation of ECH two-phase flow as claimed in any one of claims 1 to 6 or the system for gas-liquid separation of ECH two-phase flow as claimed in any one of claims 7 to 9 in the production of epichlorohydrin.

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