Gas-liquid separation assembly, gas-liquid separation device, application of gas-liquid separation device and preparation method of dimethyl ketene

Abstract

The invention discloses a gas-liquid separation assembly, a gas-liquid separation device, application and a preparation method of dimethyl ketene. The gas-liquid separation assembly comprises a cooling unit, a gas-liquid separation unit and a gas collection unit which are nested from inside to outside, wherein the gas-liquid separation unit and the cooling unit enable a to-be-separated gas-liquid mixture to be cooled by the cooling unit and to be subjected to gas-liquid separation at the same time to obtain a gas phase and a liquid phase; the gas collection unit is used for collecting the gas phase, the gas-liquid separation unit is provided with a liquid collection part, and the liquid collection part is used for collecting the liquid phase. The device has the advantages of in-situ cooling and gas-liquid separation.

Description

Technical Field

[0001] The invention relates to the technical field of gas-liquid separation, and in particular to a gas-liquid separation component, a gas-liquid separation device and application thereof, and a method for preparing dimethyl ketone. Background Art

[0002] Dimethyl ketone (DMK) is the starting material for the preparation of 2,2,4,4-tetramethyl-1,3-cyclobutanediol (CBDO). CBDO has good rigidity due to its special four-membered ring. The glass transition temperature (Tg) of the polyester modified by CBDO copolymerization increases significantly with the gradual increase of the CBDO monomer content in the system, making it an excellent member of the high-temperature resistant polyester family. At the same time, the transparency of the copolyester is very superior, making it widely used in the field of food packaging, such as drinking water cups. Compared with traditional polycarbonate (PC), CBDO-modified PCTG copolyester does not contain bisphenol A (BPA), which greatly improves the food safety of the copolyester. DMK is mostly produced industrially through thermal cracking of isobutyric acid or isobutyric anhydride. The whole process has defects such as poor stability and easy side reactions.

[0003] In traditional chemical processes, cooling and gas-liquid separation are two unit operations, which increases the complexity of the entire process and also increases the investment and floor space of the device. At the same time, due to the series effect of the two modules, the time of material cooling and gas-liquid separation is increased, making it impossible to apply to some heat-sensitive systems or systems that require rapid separation. Summary of the invention

[0004] The purpose of the present invention is to provide a gas-liquid separation component, a gas-liquid separation device and its application, and a method for preparing dimethyl ethylene ketone, which have the advantages of in-situ cooling-gas-liquid separation. Furthermore, the device of the present invention is used in the production process of dimethyl ethylene ketone, which can significantly improve the process yield.

[0005] The applicant of this application found during the research process that DMK is mostly produced industrially by thermal cracking of isobutyric acid or isobutyric anhydride. The whole process has the following two difficulties: 1) DMK is directly connected by carbon-carbon double bonds and carbon-oxygen double bonds, and its stability is poor at high temperatures; 2) DMK reacts instantly when in contact with acidic substances. All of the above determine that DMK needs to be quickly cooled and concentrated after the thermal cracking reaction.

[0006] In order to solve the above problems, the present invention provides a gas-liquid separation component on one hand, which includes a cooling unit, a gas-liquid separation unit and a gas collection unit nested from the inside to the outside; wherein,

[0007] The gas-liquid separation unit and the cooling unit allow the gas-liquid mixture to be separated to be cooled by the cooling unit while being separated into a gas phase and a liquid phase;

[0008] The gas collecting unit is used to collect the gas phase, and the gas-liquid separation unit has a liquid collecting part, and the liquid collecting part is used to collect the liquid phase.

[0009] A second aspect of the present invention provides a gas-liquid separation device, the gas-liquid separation device comprising at least one gas-liquid separation component according to the present invention;

[0010] Preferably, the gas-liquid separation device comprises a gas-liquid separation tank, at least one of the gas-liquid separation components is horizontally installed in the gas-liquid separation tank, and the cooling unit has a channel for circulating a heat exchange medium.

[0011] The gas-liquid separation component or gas-liquid separation device of the present invention is used in the preparation of ketene compounds, preferably in the preparation of dimethyl ketene.

[0012] The present invention provides a method for preparing dimethyl ethylene ketone, which comprises using the gas-liquid separation device of the present invention to separate a gas-liquid mixture containing dimethyl ethylene ketone after reaction, wherein the gas-liquid mixture is passed into a gas-liquid separation unit, and a heat exchange medium is passed into a cooling unit, so that the gas-liquid mixture is subjected to gas-liquid separation while being cooled to obtain a liquid phase and a gas phase containing dimethyl ethylene ketone.

[0013] Through the above technical scheme, the gas material can be cooled and separated from the gas-liquid in the device of the present invention, which greatly reduces the possibility of contact between the gas and liquid materials and realizes the in-situ cooling-gas-liquid separation process. The present invention is used in the industrial production of ketene and dimethyl ketene, which can greatly improve the process yield and simplify the process. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a schematic structural diagram of a gas-liquid separation component according to a specific embodiment of the present invention;

[0015] Figure 2 yes Figure 1 A radial cross-sectional view of

[0016] Figure 3 yes Figure 1 A schematic diagram of the cross-sectional structure of the gas-liquid separation layer;

[0017] Figure 4 It is a structural schematic diagram of a gas-liquid separation device according to a specific embodiment of the present invention;

[0018] Figure 5 It is a device diagram of comparative example 1;

[0019] Figure 6 This is a diagram of the device for comparative example 2.

[0020] Description of Reference Numerals

[0021] 1 gas-liquid separation tank; 2 gas-liquid separation assembly; 21 cooling medium layer; 22 gas-liquid separation layer; 23 gas collection layer; 221 liquid collection part; 222 separation part. DETAILED DESCRIPTION

[0022] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range 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 considered as specifically disclosed in this article.

[0023] In the present invention, unless otherwise specified, directional words such as "up, down, top, bottom" are usually used with reference to the directions shown in the drawings or are used to describe the relative positional relationships of components in the vertical, perpendicular or gravity directions; "inside and outside" usually refer to the inside and outside of a chamber relative to an inner chamber or the radial inside and outside relative to the center of a circle.

[0024] In one aspect, the present invention discloses a gas-liquid separation component, such as Figure 1-Figure 3 As shown, the gas-liquid separation component includes a cooling unit, a gas-liquid separation unit and a gas collection unit which are nested from the inside to the outside;

[0025] The gas-liquid separation unit and the cooling unit allow the gas-liquid mixture to be separated to be cooled by the cooling unit while being separated into a gas phase and a liquid phase; the gas collecting unit is used to collect the gas phase, and the gas-liquid separation unit has a liquid collecting part 221, which is used to collect the liquid phase.

[0026] In some embodiments of the present invention, Figure 1-Figure 3 As shown, the cooling unit includes a cooling medium layer 21, the gas-liquid separation unit includes a gas-liquid separation layer 22, and the gas collection unit includes a gas collection layer 23, wherein the cooling medium layer 21 is provided with a gas-liquid separation layer 22, and the gas-liquid separation layer 22 is provided with a gas collection layer 23, forming an attached Figure 2 The concentric wrapping arrangement shown, in which the gas-liquid mixture to be separated is passed into the gas-liquid separation layer 22 for separation and is cooled by heat exchange through the cooling medium layer 21, can achieve cooling and separation at the same time, and can adapt to heat-sensitive systems and systems that require rapid separation.

[0027] In some embodiments of the present invention, the cooling medium layer 21, the gas-liquid separation layer 22 and the gas collection layer 23 are each set to a cylindrical shape, wherein the diameter R2:R1 of the gas-liquid separation layer 22 is between 1.2 and 3, preferably between 1.5 and 2.5; the diameter R3:R2 of the gas collection layer 23 is between 1.05 and 2, preferably between 1.05 and 1.5; wherein the diameter of the cooling medium layer 21 is recorded as R1, the diameter of the gas-liquid separation layer 22 is recorded as R2, and the diameter of the gas collection layer 23 is recorded as R3. Thus, it has the advantage of in-situ cooling-gas-liquid separation.

[0028] In some embodiments of the present invention, Figure 3 As shown, the gas-liquid separation unit includes a separator (the separator can be selected from at least one of a porous stainless steel plate and a porous polytetrafluoroethylene plate. In the embodiment of the present invention, the porous polytetrafluoroethylene plate is used as an example to illustrate the advantages of the present invention, but the present invention is not limited thereto). The separator is used to separate the gas-liquid separation layer 22 into a liquid collecting portion 221 and a separation portion 222 for gas-liquid separation; wherein the liquid collecting portion can be set as a cavity with a liquid storage function. Preferably, when the gas-liquid separation component 2 is placed horizontally, the liquid collecting portion 221 is located below the separation portion 222, and the cross section (radial cross section) of the liquid collecting portion 221 is fan-shaped, wherein the central angle α of the cross section of the liquid collecting portion 221 is 90 to 270°, preferably 90 to 180°. Thus, it has the advantage of real-time collection of the liquid phase.

[0029] It should be noted that the gas collection layer 23 can be configured as a cavity formed by a shell having a gas storage function, the shell is connected to the gas-liquid separation layer 22, or a cover can be set outside the gas-liquid separation layer 22 to collect the separated gas phase; the separation part 222 of the gas-liquid separation layer 22 can be configured to include an upper and lower support body and a gas-liquid separation membrane located between the upper and lower support bodies, wherein the present invention has no special requirements on the shape and material of the support body, and its shape can be any shape as long as it can achieve gas-liquid separation while cooling, for example Figure 1-Figure 3 The layered arrangement shown in the figure, the material of the support body includes but is not limited to a stainless steel orifice plate. In some embodiments of the present invention, the gas-liquid separation membrane of the separation part 222 can select a hydrophilic membrane or an oleophilic membrane according to the physical properties of the liquid phase system to be separated. In the present invention, there is no special requirement for the hydrophilic membrane or the oleophilic membrane, and the commonly used hydrophilic membrane or the oleophilic membrane can be used in the present invention. The following exemplary description, but not limiting the scope of the present invention, the hydrophilic membrane is selected from at least one of glass fiber, molecular sieve or modified polyacrylonitrile; the oleophilic membrane is selected from at least one of polydimethylsiloxane, polyurethane or modified polyvinylidene fluoride. For example, in the embodiments of the present invention, a mixture of dimethyl ketone and isobutyric acid / isobutyric anhydride, and a mixture of ketone and acetic acid / water are separated. The oleophilic polyvinylidene fluoride membrane and the hydrophilic glass fiber membrane are respectively used to illustrate the advantages of the present invention, but the present invention is not limited to this.

[0030] The present invention discloses a gas-liquid separation device based on the aforementioned gas-liquid separation component 2, and the gas-liquid separation device includes at least one gas-liquid separation component 2 of the present invention. In the embodiment of the present invention, three gas-liquid separation components 2 are installed as an example to illustrate the advantages of the present invention, but the present invention is not limited thereto;

[0031] Preferably, if Figure 1-Figure 4 As shown, the gas-liquid separation device includes a gas-liquid separation tank 1, at least one gas-liquid separation component 2 is horizontally installed in the gas-liquid separation tank 1, and the cooling medium layer of the cooling unit has a channel for circulating heat exchange medium, which can realize inter-wall heat exchange with the gas-liquid separation layer 22.

[0032] Specifically, in some embodiments of the present invention, Figure 4 As shown, a plurality of gas-liquid separation components 2 are horizontally spaced apart in a gas-liquid separation tank 1, and a heat exchange medium inlet, a heat exchange medium outlet, a gas-liquid mixture inlet, a gas outlet, and a liquid outlet (not shown) are provided on the gas-liquid separation tank 1; wherein, the channel of the cooling medium layer 21 of each gas-liquid separation component is connected to the heat exchange medium inlet and the heat exchange medium outlet to realize the inflow and outflow of the heat exchange medium. There is no special requirement for the heat exchange medium in the present invention, and commonly used heat exchange media can be used in the present invention. The following exemplary description does not limit the scope of the present invention. In some embodiments of the present invention, the heat exchange medium can be selected from one of desalted water, ethanol or Freon; the gas-liquid mixture inlet is connected to the separation part 222 of the gas-liquid separation layer 22 of each gas-liquid separation component; the gas outlet is connected to the gas collecting layer 23 of each gas-liquid separation component to discharge the separated gas phase, and the liquid outlet is connected to the liquid collecting part 221 of the gas-liquid separation layer 22 of each gas-liquid separation component to discharge the separated liquid phase.

[0033] The gas-liquid separation component or gas-liquid separation device of the present invention is used in the preparation of ketene compounds, preferably in the preparation of dimethyl ketene.

[0034] The applicant of the present application found during the research process that DMK is mostly produced industrially through thermal cracking of isobutyric acid or isobutyric anhydride. The whole process has the following two difficulties: 1) DMK is a direct connection between carbon-carbon double bonds and carbon-oxygen double bonds, and its stability is poor at high temperatures; 2) DMK will react instantly when in contact with acidic substances.

[0035] In order to solve the above problems, the present invention discloses a method for preparing dimethyl ketene on the basis of the above disclosure, which comprises using the gas-liquid separation device of the present invention to separate the gas-liquid mixture containing dimethyl ketene after the reaction, wherein the gas-liquid mixture is passed into a gas-liquid separation unit, and a heat exchange medium is passed into a cooling unit, so that the gas-liquid mixture is subjected to gas-liquid separation while being cooled to obtain a liquid phase and a gas phase containing dimethyl ketene. In this way, the in-situ separation of the gas phase and the liquid phase can be achieved.

[0036] In some embodiments of the present invention, the reaction includes thermal cracking of isobutyric acid or isobutyric anhydride to produce dimethyl ketene, wherein the conditions of the thermal cracking include:

[0037] The temperature of the thermal cracking process is 300-800°C, preferably 300-700°C;

[0038] The partial pressure of the reaction raw materials in the thermal cracking process is 0.1-20 kPa, preferably 2-15 kPa;

[0039] The residence time of the thermal cracking process is 0.01 to 10 seconds, preferably 0.1 to 2 seconds. It should be noted that the conditions for the thermal cracking of isobutyric anhydride to generate dimethyl ketene in the embodiment of the present invention are a thermal cracking temperature of 450°C, a partial pressure of 10 kPa of isobutyric anhydride raw material, nitrogen as the remaining gas, and a thermal cracking residence time of 0.5 seconds as an example to illustrate the advantages of the present invention, but the present invention is not limited thereto.

[0040] The present invention has no special requirements for the reaction device. A conventional reaction device in the prior art that can thermally crack isobutyric acid or isobutyric anhydride to generate dimethyl ketene can be used. The discharge port of the reaction device is connected to the gas-liquid mixture inlet of the gas-liquid separation tank to pass the gas-liquid mixture containing dimethyl ketene into the gas-liquid separation device to realize real-time cooling and gas-liquid separation of DMK.

[0041] In some embodiments of the present invention, the residence time of the gas-liquid mixture containing dimethyl ketene after the reaction in the gas-liquid separation tank 1 is 0.01-10 s, preferably 0.1-2 s.

[0042] In some embodiments of the present invention, the terminal temperature of cooling is -10 to 180°C, preferably -10 to 100°C.

[0043] The advantages of the present invention will be described below by way of examples, but the present invention is not limited thereto.

[0044] The following examples contain a gas-liquid mixture of the target product after the reaction. Figure 1-Figure 4 The gas-liquid separation tank shown in the figure is used for separation. The tank body of the gas-liquid separation tank 1 is provided with a heat exchange medium inlet, a heat exchange medium outlet, a gas-liquid mixture inlet, a gas outlet, and a liquid outlet (not shown). Three gas-liquid separation components 2 are installed in the gas-liquid separation tank. The axes of the three gas-liquid separation components 2 are parallel to the axis of the gas-liquid separation tank and are distributed at intervals.

[0045] like Figure 1-Figure 3 As shown, each gas-liquid separation component 2 includes a cylindrical cooling medium layer 21, a gas-liquid separation layer 22 and a gas collection layer 23 arranged from the inside to the outside; wherein,

[0046] The cooling medium layer 21 is configured as a pipeline, and the two ends of the pipeline are respectively connected to the heat exchange medium inlet and the heat exchange medium outlet; the partition in the gas-liquid separation layer 22 separates the gas-liquid separation layer 22 into a liquid collecting portion 221 and a separation portion 222, wherein the separation portion 222 is connected to the gas-liquid mixture inlet, and the separation portion 222 is configured as a support body (support skeleton) including upper and lower layers of arc-shaped stainless steel orifice plates and a gas-liquid separation membrane located between the upper and lower layers of the support body, and the liquid collecting portion is configured as a cavity structure connected to the liquid outlet, such as Figure 3 As shown, the cavity structure and the support body are combined to form a cylindrical gas-liquid separation layer 22 sleeved outside the cooling medium layer; the gas collecting layer 23 is set as a cavity formed by a shell, which covers the outside of the gas-liquid separation layer 22 and is connected to the gas outlet.

[0047] The method of the following embodiment comprises: introducing a gas-liquid mixture containing a target product into a gas-liquid mixture inlet, and introducing a heat exchange medium Freon into a heat exchange medium inlet.

[0048] Example 1

[0049] The parameters of the gas-liquid separation assembly used in this embodiment are as follows: R2: R1 = 1.5, R3: R2 = 1.3, the central angle α of the cross section of the liquid collecting part 221 is 120°, the gas-liquid separation unit separator is a porous polytetrafluoroethylene plate, and the gas-liquid separation membrane of the separation part 222 is a polyvinylidene fluoride membrane. Three of the above-mentioned gas-liquid separation assemblies are installed in the gas-liquid separation device of this embodiment.

[0050] In this embodiment, the conditions for thermal cracking of isobutyric anhydride to produce dimethyl ketene are as follows: a thermal cracking temperature of 450° C., a partial pressure of the isobutyric anhydride raw material of 10 kPa, the remaining gas being nitrogen, and a thermal cracking residence time of 0.5 s.

[0051] The cooling-gas-liquid separation terminal temperature of this embodiment is 30° C. After cooling-gas-liquid separation, the removal rate of AIB in the system reaches 99.31%, the removal rate of ANIB reaches 99.57%, and the recovery rate of DMK reaches 90.37%.

[0052] Example 2

[0053] The parameters of the gas-liquid separation assembly used in this embodiment are as follows: R2: R1 = 2, R3: R2 = 1.5, the central angle α of the cross section of the liquid collecting part (221) is 180°, the gas-liquid separation unit separator is a porous polytetrafluoroethylene plate, and the gas-liquid separation membrane of the separation part 222 is a polyvinylidene fluoride membrane. Three of the above-mentioned gas-liquid separation assemblies are installed in the gas-liquid separation device of this embodiment.

[0054] In this embodiment, the conditions for thermal cracking of isobutyric anhydride to produce dimethyl ketene are as follows: a thermal cracking temperature of 450° C., a partial pressure of the isobutyric anhydride raw material of 10 kPa, the remaining gas being nitrogen, and a thermal cracking residence time of 0.5 s.

[0055] The cooling-gas-liquid separation terminal temperature of this embodiment is 30° C. After cooling-gas-liquid separation, the removal rate of AIB in the system reaches 99.55%, the removal rate of ANIB reaches 99.83%, and the recovery rate of DMK reaches 85.12%.

[0056] Example 3

[0057] The parameters of the gas-liquid separation assembly used in this embodiment are as follows: R2: R1 = 2.5, R3: R2 = 1.1, the central angle α of the cross section of the liquid collecting part 221 is 90°, the gas-liquid separation unit separator is a porous polytetrafluoroethylene plate, and the gas-liquid separation membrane of the separation part 222 is a polyvinylidene fluoride membrane. Three of the above-mentioned gas-liquid separation assemblies are installed in the gas-liquid separation device of this embodiment.

[0058] In this embodiment, the conditions for thermal cracking of isobutyric anhydride to produce dimethyl ketene are as follows: a thermal cracking temperature of 450° C., a partial pressure of the isobutyric anhydride raw material of 10 kPa, the remaining gas being nitrogen, and a thermal cracking residence time of 0.5 s.

[0059] The cooling-gas-liquid separation terminal temperature of this embodiment is 30° C. After cooling-gas-liquid separation, the removal rate of AIB in the system reaches 99.49%, the removal rate of ANIB reaches 99.91%, and the recovery rate of DMK reaches 92.37%.

[0060] Example 4

[0061] The parameters of the gas-liquid separation assembly used in this embodiment are as follows: R2: R1 = 1.2, R3: R2 = 1.8, the central angle α of the cross section of the liquid collecting part 221 is 90°, the gas-liquid separation unit separator is a porous polytetrafluoroethylene plate, and the gas-liquid separation membrane of the separation part 222 is a polyvinylidene fluoride membrane. Three of the above-mentioned gas-liquid separation assemblies are installed in the gas-liquid separation device of this embodiment.

[0062] In this embodiment, the conditions for thermal cracking of isobutyric anhydride to produce dimethyl ketene are as follows: a thermal cracking temperature of 450° C., a partial pressure of the isobutyric anhydride raw material of 10 kPa, the remaining gas being nitrogen, and a thermal cracking residence time of 0.5 s.

[0063] The cooling-gas-liquid separation terminal temperature of this embodiment is 30° C. After cooling-gas-liquid separation, the removal rate of AIB in the system reaches 98.53%, the removal rate of ANIB reaches 98.92%, and the recovery rate of DMK reaches 80.17%.

[0064] Example 5

[0065] The parameters of the gas-liquid separation assembly used in this embodiment are as follows: R2: R1 = 1.2, R3: R2 = 1.8, the central angle α of the cross section of the liquid collecting part 221 is 250°, the gas-liquid separation unit separator is a porous polytetrafluoroethylene plate, and the gas-liquid separation membrane of the separation part 222 is a polyvinylidene fluoride membrane. Three of the above-mentioned gas-liquid separation assemblies are installed in the gas-liquid separation device of this embodiment.

[0066] In this embodiment, the conditions for thermal cracking of isobutyric anhydride to produce dimethyl ketene are as follows: a thermal cracking temperature of 450° C., a partial pressure of the isobutyric anhydride raw material of 10 kPa, the remaining gas being nitrogen, and a thermal cracking residence time of 0.5 s.

[0067] The cooling-gas-liquid separation terminal temperature of this embodiment is 30° C. After cooling-gas-liquid separation, the removal rate of AIB in the system reaches 99.25%, the removal rate of ANIB reaches 99.69%, and the recovery rate of DMK reaches 75.32%.

[0068] Example 6

[0069] The parameters of the gas-liquid separation assembly used in this embodiment are as follows: R2: R1 = 1.8, R3: R2 = 1.1, the central angle α of the cross section of the liquid collecting part 221 is 120°, the gas-liquid separation unit separator is a porous polytetrafluoroethylene plate, and the gas-liquid separation membrane of the separation part 222 is a glass fiber membrane. Three of the above-mentioned gas-liquid separation assemblies are installed in the gas-liquid separation device of this embodiment.

[0070] The conditions for the thermal cracking of acetic acid to produce ketene in this embodiment are as follows: a thermal cracking temperature of 750° C., a partial pressure of acetic acid raw material of 10 kPa, nitrogen as the remaining gas, and a thermal cracking residence time of 0.7 s.

[0071] The cooling-gas-liquid separation end point temperature of this embodiment is 10° C. After cooling-gas-liquid separation, the removal rate of acetic acid in the system reaches 99.72%, the removal rate of water reaches 99.84%, and the recovery rate of ethylene ketone reaches 97.31%.

[0072] Comparative Example 1

[0073] The conditions for the thermal cracking of isobutyric anhydride to produce dimethyl ketene in this comparative example are as follows: the thermal cracking temperature is 450° C., the partial pressure of the isobutyric anhydride raw material is 10 kPa, the remaining gas is nitrogen, and the thermal cracking residence time is 0.5 s.

[0074] The product after the reaction was Figure 5 The shell and tube heat exchanger shown is cooled to 30°C, and the gas-liquid mixture at the outlet of the shell and tube heat exchanger is separated into gas and liquid by a cyclone separator. The removal rate of AIB in the system reaches 95.73%, the removal rate of ANIB reaches 95.29%, and the recovery rate of DMK is 36.19%.

[0075] Comparative Example 2

[0076] The conditions for the thermal cracking of acetic acid to produce ketene in this embodiment are as follows: a thermal cracking temperature of 750° C., a partial pressure of acetic acid raw material of 10 kPa, nitrogen as the remaining gas, and a thermal cracking residence time of 0.7 s.

[0077] The product after the reaction was Figure 6 The three-stage shell-and-tube heat exchanger shown is cooled to 10°C, and a gas-liquid separation tank is arranged after each stage of the heat exchanger. The acetic acid removal rate in the system reaches 98.13%, the water removal rate reaches 98.52%, and the ketene recovery rate is 93.28%.

[0078] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A gas-liquid separation component, characterized in that: The gas-liquid separation component comprises a cooling unit, a gas-liquid separation unit and a gas collection unit which are nested from inside to outside; wherein, The gas-liquid separation unit and the cooling unit allow the gas-liquid mixture to be separated to be cooled by the cooling unit while being separated into a gas phase and a liquid phase; The gas collection unit is used to collect the gas phase, and the gas-liquid separation unit has a liquid collection part (221) for collecting the liquid phase.

2. The gas-liquid separation assembly according to claim 1, characterized in that: The cooling unit comprises a cooling medium layer (21), the gas-liquid separation unit comprises a gas-liquid separation layer (22), and the gas collection unit comprises a gas collection layer (23), wherein the gas-liquid separation layer (22) is disposed outside the cooling medium layer (21), and the gas-liquid separation layer (22) is disposed outside the gas collection layer (23).

3. The gas-liquid separation assembly according to claim 2, characterized in that: The cooling medium layer (21), the gas-liquid separation layer (22) and the gas collection layer (23) are each configured in a cylindrical shape, wherein: The diameter R2:R1 of the gas-liquid separation layer (22) is between 1.2 and 3, preferably between 1.5 and 2.5; and / or The diameter R3:R2 of the gas collection layer (23) is between 1.05 and 2, preferably between 1.05 and 1.5; The diameter of the cooling medium layer (21) is denoted as R1, the diameter of the gas-liquid separation layer (22) is denoted as R2, and the diameter of the gas collection layer (23) is denoted as R3.

4. The gas-liquid separation assembly according to claim 2 or 3, characterized in that: The gas-liquid separation unit comprises a partition, wherein the partition is used to separate the gas-liquid separation layer (22) into a liquid collecting portion (221) and a separation portion (222) for gas-liquid separation; Preferably, when the gas-liquid separation component (2) is placed horizontally, the liquid collecting portion (221) is located below the separation portion (222), and the cross-section of the liquid collecting portion (221) is fan-shaped, wherein the central angle α of the cross-section of the liquid collecting portion (221) is 90 to 270°, preferably 90 to 180°.

5. The gas-liquid separation assembly according to claim 4, characterized in that: The separation part (222) includes a hydrophilic membrane or an oleophilic membrane; and / or Preferably, The hydrophilic membrane is selected from at least one of glass fiber, molecular sieve, and modified polyacrylonitrile; and / or The oleophilic film is selected from at least one of polydimethylsiloxane, polyurethane and modified polyvinylidene fluoride.

6. A gas-liquid separation device, characterized in that: The gas-liquid separation device comprises at least one gas-liquid separation component (2) according to any one of claims 1 to 5; Preferably, the gas-liquid separation device comprises a gas-liquid separation tank (1), at least one gas-liquid separation component (2) is horizontally installed in the gas-liquid separation tank (1), and the cooling unit has a channel for circulating a heat exchange medium.

7. Use of the gas-liquid separation component according to any one of claims 1 to 5 or the gas-liquid separation device according to claim 6 in the preparation of ketene compounds, preferably in the preparation of dimethyl ketene.

8. A method for preparing dimethyl ketene, characterized in that: The preparation method comprises using the gas-liquid separation device described in claim 6 to separate the gas-liquid mixture containing dimethyl ethylene ketone after the reaction, wherein the gas-liquid mixture is passed into a gas-liquid separation unit, and a heat exchange medium is passed into a cooling unit, so that the gas-liquid mixture is subjected to gas-liquid separation while being cooled to obtain a liquid phase and a gas phase containing dimethyl ethylene ketone.

9. The preparation method according to claim 8, wherein: The gas-liquid mixture containing dimethyl ketene after the reaction comes from the thermal cracking reaction of isobutyric acid or isobutyric anhydride, wherein the conditions of the thermal cracking reaction include: The temperature of the thermal cracking process is 300-800°C, preferably 300-700°C; The partial pressure of the reaction raw materials in the thermal cracking process is 0.1-20 kPa, preferably 2-15 kPa; The residence time of the thermal cracking process is 0.01 to 10 s, preferably 0.1 to 2 s.

10. The preparation method according to claim 8 or 9, wherein: The residence time of the gas-liquid mixture containing dimethyl ketene after the reaction in the gas-liquid separation tank (1) is 0.01-10 s, preferably 0.1-2 s; and / or The final temperature of cooling is -10 to 180°C, preferably -10 to 100°C.

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