Method and equipment for preparing 1, 1, 2-trichloroethane
Through static mixing equipment and segmented feeding technology, the problems of high catalyst costs and poor mass transfer of gas and liquid in the tower reactor in the existing technology are solved, and the efficient preparation of 1,1,2-trichloroethane is achieved, which improves the improvement of 1,1,2-trichloroethane. Conversion and selectivity simplify the process flow.
Patent Information
- Application Number
- CN202411220588.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-02
- Publication Date
- 2024-12-10
AI Technical Summary
The prior art requires catalysts when preparing 1,1,2-trichloroethane, which leads to high cost and complex process, and the gas-liquid mass transfer effect of the tower reactor is poor, resulting in uneven ratio of Cl2 and VCM, resulting in relatively relatively high production. More polychlorinated compounds reduce reaction selectivity.
Using static mixing equipment, including injection reactors, impact flow reactors and static mixing components, the reaction with chlorine gas through vinyl chloride and circulating medium 1,1,2-trichloroethane in a multi-stage mixing device is avoided. The use of dynamic equipment improves process stability and reliability, and optimizes the feeding of Cl2 through segmented feeding, improving the reaction effect.
无需催化剂即可将VCM转化率提升至99%以上,1,1,2-TCE选择性提升至99%以上,简化了设备结构和操作,适合工业生产。
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Figure CN119098113A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a method and equipment for preparing 1,1,2-trichloroethane. Background Art
[0002] 1,1,2-Trichloroethane (1,1,2-TCE) is an important chemical raw material that can be used to prepare vinylidene chloride chemical products. At present, 1,1,2-trichloroethane is mainly produced using vinyl chloride (VCM) and chlorine as raw materials. The reaction equation is:
[0003] CHCl=CH2+Cl2→CHCl2-CH2Cl
[0004] Currently, many documents and patents disclose methods for preparing 1,1,2-TCE, but most of these methods require the use of catalysts or tower reactors. The use of catalysts increases costs on the one hand, and makes the production process more complicated and cumbersome on the other. The use of tower reactors to produce 1,1,2-TCE often has poor gas-liquid mass transfer effects, which can easily lead to uneven ratios of Cl2 and VCM, thereby generating more polychlorides and reducing reaction selectivity. Based on the above problems, Shanghai Chlor-Alkali Chemical Co., Ltd. has developed a method for producing 1,1,2-TCE by combining a tubular reactor with a static mixing device (publication number CN1793093A).
[0005] There is still a need in the art for a new method and apparatus for preparing 1,1,2-trichloroethane that can overcome the deficiencies of the prior art. Summary of the invention
[0006] The present invention discloses a method and device for preparing 1,1,2-trichloroethane, which overcomes the shortcomings of the prior art and further improves the reaction performance. In particular, the mixing equipment used in the present invention is static equipment, avoiding the use of dynamic equipment, and improving the stability and reliability of the process.
[0007] On the one hand, the present application provides a method for preparing 1,1,2-trichloroethane, the method comprising the following steps:
[0008] Vinyl chloride and circulating medium 1,1,2-trichloroethane are mixed in the first mixing device, and then enter the second mixing device and the third mixing device in sequence to react with chlorine to generate 1,1,2-trichloroethane;
[0009] A portion of the reaction product 1,1,2-trichloroethane is sent to the first mixing device as a circulating medium, and the remaining reaction products enter the subsequent purification process.
[0010] The second mixing device comprises at least a first section and a second section, wherein the first section is a jet reactor, an impinging stream reactor and / or a venturi reactor; and the second section is a pipeline reactor having an SV type static mixing member.
[0011] The third mixing device comprises at least one pipeline reactor of SL type, SV type and / or SH type static mixing member,
[0012] At least the second mixing device, the third mixing device and a chlorine gas inlet are provided between the second mixing device and the third mixing device.
[0013] On the other hand, the present application provides a device for preparing 1,1,2-trichloroethane, the device comprising:
[0014] a first mixing device having a vinyl chloride inlet and a circulating medium inlet,
[0015] a second mixing device, and
[0016] The third mixing device,
[0017] The second mixing device comprises at least a first section and a second section, wherein the first section is a jet reactor and / or an impinging stream reactor; and the second section is a pipeline reactor having an SV type static mixing member.
[0018] The third mixing device comprises at least one pipeline reactor of SL type, SV type and / or SH type static mixing member,
[0019] At least the second mixing device, the third mixing device and a chlorine gas inlet are provided between the second mixing device and the third mixing device. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 One embodiment of the method and apparatus of the present application is described.
[0021] Figure 2 The specific structure of the Venturi-type jet reactor is described. DETAILED DESCRIPTION
[0022] "Scope" disclosed herein is defined in the form of lower limit and upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a particular range. The scope defined in this way can be including end values or not including end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a scope. For example, if the scope of 60-120 and 80-110 is listed for a particular parameter, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4 and 5 are listed, the following scope can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In this application, unless otherwise specified, the numerical range "ab" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.
[0023] In this application, unless otherwise specified, all embodiments and preferred embodiments mentioned herein can be combined with each other to form a new technical solution.
[0024] In this application, unless otherwise specified, all technical features and preferred features mentioned herein can be combined with each other to form a new technical solution.
[0025] In the present application, unless otherwise specified, all steps mentioned herein may be performed sequentially or randomly, but are preferably performed sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.
[0026] In this application, unless otherwise specified, the terms "include" and "comprising" mentioned herein may be open-ended or closed-ended. For example, the terms "include" and "comprising" may mean that other components not listed may also be included or only the listed components may be included or only the listed components may be included.
[0027] In the description of this article, it should be noted that, unless otherwise specified, "above" and "below" are inclusive of the number itself, and "several" in "one or several" means two or more.
[0028] In the description herein, unless otherwise specified, the term "or" is inclusive. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, any of the following conditions satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).
[0029] In this context, unless otherwise specified, "a combination thereof" means a multi-component mixture of the elements described, for example a mixture of two, three, four and up to the maximum possible multi-component mixture.
[0030] If not specifically stated, the terms "a" or "an" used in the present specification means "at least one".
[0031] Herein, unless otherwise stated, all reactions are carried out at normal temperature and pressure.
[0032] On the one hand, the present application provides a method for preparing 1,1,2-trichloroethane, the method comprising the following steps:
[0033] Vinyl chloride and circulating medium 1,1,2-trichloroethane are mixed in the first mixing device, and then enter the second mixing device and the third mixing device in sequence to react with chlorine to generate 1,1,2-trichloroethane;
[0034] A portion of the reaction product 1,1,2-trichloroethane is sent to the first mixing device as a circulating medium, and the remaining reaction products enter the subsequent purification process.
[0035] The second mixing device comprises at least a first section and a second section, wherein the first section is a jet reactor and / or an impinging stream reactor; and the second section is a pipeline reactor having an SV type static mixing member.
[0036] The third mixing device comprises at least one pipeline reactor of SL type, SV type and / or SH type static mixing member,
[0037] At least the second mixing device, the third mixing device and a chlorine gas inlet are provided between the second mixing device and the third mixing device.
[0038] In the present application, the first mixing device may be a jet reactor, an impinging stream reactor, a reaction pipe equipped with a static mixing component, or a combination thereof. The jet reactor may be a type commonly used in the art, such as a jet pump, the definition of which is detailed in GB / T 41513-2022. In one example of the present application, the jet reactor comprises a venturi tube reactor. The venturi tube reactor is a type commonly used in the art, and is designed and manufactured in accordance with GB / T 2624-2006. The impinging stream reactor is a type commonly used in the art, such as a multi-nozzle impinging stream reactor. In one example of the present application, the impinging stream reactor generally refers to a double-nozzle opposed impinging stream reactor.
[0039] The reaction pipe equipped with the static mixing component can be a reaction pipe with a conventional static mixing component commonly used in the art. According to the national standard for static mixers: JB / T 7660-2016, the types of static mixing components are generally divided into SV type, SK type, SX type, SL type, SH type and combinations thereof. In one example of the present application, the reaction pipe equipped with the static mixing component can be a reaction pipe with a mixing component of SV type, SK type, SX type, SL type, SH type and a combination thereof.
[0040] In the present application, the second mixing device is connected to the first mixing device (e.g., through a pipeline), and includes at least a first section and a second section, wherein the first section is a jet reactor and / or an impinging stream reactor; and the second section is a pipeline reactor with an SV-type static mixing member. The jet reactor, impinging stream reactor, and pipeline reactor with an SV-type static mixing member can refer to the description of the first mixing device.
[0041] In one example of the present application, the second mixing device has at least a first section and a second section, for example, two sections, three sections or four sections. In one example of the present application, the sections are connected in series, and the order of the sections can be arranged arbitrarily. The terms "first section", "second section", "third section", "fourth section", etc. do not mean that the first section is arranged in front of the second section, the third section and the fourth section, and so on. The second section can be in front of the first section, or behind the third section and the fourth section. In addition to the first section and the second section, other sections in the second mixing device (such as the third section, the fourth section, etc.) can be a jet reactor, an impinging flow reactor, a reaction pipe equipped with a static mixing component, or a combination thereof.
[0042] The second mixing device has at least one chlorine inlet (e.g., one, two, three or four chlorine inlets). In an example of the present application, the chlorine inlet is in any one section of the second mixing device. In a preferred embodiment of the present application, each section of the second mixing device has a chlorine inlet.
[0043] In a preferred embodiment of the present application, the second mixing device has two sections, wherein the first section is a jet reactor (e.g., a Venturi tube reactor) or an impinging flow reactor (e.g., a double-nozzle opposed impinging flow reactor), and the second section is a pipeline reactor having an SV-type static mixing component.
[0044] In the present application, the third mixing device is connected to the second mixing device (for example, through a pipeline). The third mixing device includes at least one section of a pipeline reactor of SL type, SV type and / or SH type static mixing components. In an example of the present application, the third mixing device may have at least one section, for example, one section, two sections, three sections, four sections or five sections. In addition to at least one section of a pipeline reactor of SL type, SV type and / or SH type static mixing components, each section of the third mixing device may be a jet reactor, an impinging flow reactor, a reaction pipeline equipped with a static mixing component, or a combination thereof. The various sections of the third mixing device are connected in series, and the connection order can be arranged arbitrarily.
[0045] In one example of the present application, the third mixing device has one section, which includes a pipeline reactor of SL type, SV type and / or SH type static mixing member (e.g., a pipeline reactor with SL type static mixing member). In another example of the present application, the third mixing device has two sections, wherein the first section includes a pipeline reactor of SL type, SV type and / or SH type static mixing member (e.g., a pipeline reactor with SV type static mixing member), and the second section includes a pipeline reactor of SL type, SV type and / or SH type static mixing member (e.g., a pipeline reactor with SH type static mixing member). The terms "first section", "second section", "third section", "fourth section", etc. do not mean that the first section is arranged in front of the second section, the third section and the fourth section, and so on. The second section can be in front of the first section, or behind the third section and the fourth section.
[0046] In the present application, there is a chlorine inlet between the second mixing device and the third mixing device. The third mixing device has at least one chlorine inlet (e.g., one, two, three or four chlorine inlets). In an example of the present application, the chlorine inlet is in any section of the third mixing device. In a preferred embodiment of the present application, each section of the third mixing device has a chlorine inlet.
[0047] The process conditions for preparing 1,1,2-TCE are conventional in the art. For example, see CN1793093A and its embodiments. In a preferred embodiment of the present application, the process conditions are as follows:
[0048] VCM airspeed 0.01-0.33s -1 , preferably 0.01-0.20s-1 ;
[0049] Liquid phase circulation volume (1,1,2-TCE liquid phase volume m 3 : VCM feed amount Nm 3 ) is greater than 0.57, preferably greater than 0.60, more preferably greater than 0.68, for example 0.57-1.5;
[0050] The empty tube liquid velocity (referring to the ratio of the volume flow rate of 1,1,2-TCE to the cross-sectional area of the static mixing pipe reactor) is greater than 0.3 m / s, preferably greater than 0.48 m / s, for example 0.3-1.0 m / s;
[0051] Reaction temperature 30-95°C, preferably 38-82°C;
[0052] Cl2: VCM (molar ratio) is 0.86-1.20, preferably 0.90-1.10, more preferably 0.93-1.06;
[0053] The residence time is greater than 6.0 s, for example 6-15 s.
[0054] In particular, the inventors also found that the use of segmented feeding to feed Cl2 into the mixing device can achieve better reaction results than single-stage feeding, further improve the selectivity of the product 1,1,2-TCE, and effectively reduce the occurrence of side reactions. For example, the chlorine inlet of the second mixing device, the chlorine inlet after the second mixing device (including the chlorine inlet between the second mixing device and the third mixing device and the chlorine inlet of the third mixing device) are fed with chlorine in the following ratios: (20-80): (80-20), preferably (30-70): (70-30), preferably (40-60): (60-40).
[0055] If the second mixing device has two or more chlorine inlets (e.g., two, three or four chlorine inlets), each chlorine inlet may be fed with chlorine in the same or different amounts. In one example of the present application, the second mixing device has two chlorine inlets, and the ratio of chlorine fed into each chlorine inlet is (20-80): (80-20), preferably (30-70): (70-30), and better (30-50): (50-80).
[0056] The chlorine inlet between the second mixing device and the third mixing device and the chlorine inlet of the third mixing device can be fed with chlorine in the same or different amounts. In one example of the present application, the ratio of the chlorine inlet between the second mixing device and the third mixing device and the chlorine inlet of the third mixing device is (20-80): (80-20), preferably (30-70): (70-30), and better (30-50): (50-80). If the third mixing device has two or more chlorine inlets (e.g., two, three or four chlorine inlets), each chlorine inlet can be fed with chlorine in the same or different amounts.
[0057] On the other hand, the present application provides a device for preparing 1,1,2-trichloroethane, the device comprising:
[0058] a first mixing device having a vinyl chloride inlet and a circulating medium inlet,
[0059] a second mixing device, and
[0060] The third mixing device,
[0061] The second mixing device comprises at least a first section and a second section, wherein the first section is a jet reactor and / or an impinging stream reactor; and the second section is a pipeline reactor having an SV type static mixing member.
[0062] The third mixing device comprises at least one pipeline reactor of SL type, SV type and / or SH type static mixing member,
[0063] At least the second mixing device, the third mixing device and a chlorine gas inlet are provided between the second mixing device and the third mixing device.
[0064] For the description of the first mixing device, the second mixing device, the third mixing device and the chlorine gas inlet, please refer to the description of the method.
[0065] Figure 1An embodiment of the method and apparatus of the present application is described. The circulating medium 1,1,2-trichloroethane and vinyl chloride enter the first mixing device 1 through the 1,1,2-trichloroethane inlet and the vinyl chloride inlet respectively, and are fully mixed therein. The mixed circulating medium 1,1,2-trichloroethane and vinyl chloride leave the first mixing device 1 and enter the second mixing device 2, which has two sections, each of which has a chlorine inlet 2.1 and 2.2. Vinyl chloride and chlorine are mixed and reacted in the second mixing device, and then enter the third mixing device 3 from the second mixing device 2. Chlorine inlet 2.3 between the second mixing device 2 and the third mixing device 3. The third mixing device 3 has a chlorine inlet 3.1. Chlorine and vinyl chloride are fully mixed and reacted in the third mixing device 3 to form a 1,1,2-trichloroethane product. The 1,1,2-trichloroethane product is separated by a gas-liquid separator 4, and a portion of the product (optionally with the addition of other 1,1,2-trichloroethane) is input into the first mixing device 1 as a circulating medium. The other part of the product enters the next step of purification.
[0066] Figure 2 The specific structure of the Venturi-type jet reactor is described.
[0067] In summary, the equipment of the present application has a simple structure, is easy to operate and does not require the use of a catalyst. It can increase the VCM conversion rate to more than 99% and the 1,1,2-TCE selectivity to more than 99%, which is conducive to the promotion and use of industrial production.
[0068] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples. The experimental methods in the following examples without specifying specific conditions are carried out according to conventional methods and conditions, or selected according to the product specifications.
[0069] Main reagents for the experiment
[0070]
[0071]
[0072] Main experimental instruments
[0073] Instrument Name model Manufacturer Venturi jet reactor custom made Shanghai Research Institute of Chemical Industry Pipeline of SL type static mixing element SL Shanghai Research Institute of Chemical Industry SK type static mixing element pipeline SK Shanghai Research Institute of Chemical Industry SX type static mixing element pipeline SX Shanghai Research Institute of Chemical Industry SV type static mixing element pipeline SV Shanghai Research Institute of Chemical Industry SH type static mixing element pipeline SH Shanghai Research Institute of Chemical Industry Double-nozzle opposed impinging stream reactor custom made Shanghai Research Institute of Chemical Industry Gas-Liquid Separator custom made Shanghai Research Institute of Chemical Industry
[0074] SL, SK, SX, SV and SH type tubular reactors
[0075] Design pressure: 2MPa, maximum allowable working pressure: 2MPa, pressure test pressure: 2.5MPa, design temperature: -50~150℃, size: Length 15cm, Material: PTFE or 304 stainless steel
[0076] Venturi jet reactor ( Figure 2 )
[0077] Design pressure: 5MPa, maximum allowable working pressure: 4.9MPa, pressure test pressure: 6.5MPa, design temperature: -50~200℃, dimensions: l1: 1cm; l2: 2cm; d1: 0.5cm; d2: 1.6cm; d3: 3cm; α: 8°; β: 23°, material: 304 stainless steel
[0078] Double-nozzle opposed impinging stream reactor
[0079] Design temperature: -50~200℃, Dimensions: Entrance tube length: 5cm; Nozzle diameter: 1cm; Nozzle spacing: 3cm, Material: 304 stainless steel
[0080] Gas-Liquid Separator
[0081] Design pressure: 6MPa, maximum allowable working pressure: 5.8MPa, pressure test pressure: 7.6MPa, design temperature: 0~200℃, size: 80mm*280mm, material: 304 stainless steel
[0082] Specific test methods used in the embodiments:
[0083] VCM conversion rate = (VCM feed concentration - VCM concentration at the outlet of the third mixing device) / VCM feed concentration
[0084] 1,1,2-TCE selectivity = 1,1,2-TCE concentration at the outlet of the third mixing device / sum of the concentrations of various substances at the outlet.
[0085] Comparative Example 1
[0086] refer to Figure 1 The method and apparatus shown in the figure, wherein VCM and the circulating medium 1,1,2-TCE are mixed in the first mixing device, and then enter the second mixing device, and are mixed with Cl2 entering from the inlet 2.1 for pre-reaction. Then enter the third mixing device to continue the reaction to generate 1,1,2-TCE. After the reaction product flows out of the third mixing device, the unreacted gas and a small amount of hydrogen chloride are separated by a gas-liquid separator, and part of the 1,1,2-TCE liquid phase enters the subsequent refining section as a product, and part of the 1,1,2-TCE liquid phase is recycled.
[0087] Reaction process conditions:
[0088] VCM feed rate: 10.0Nm 3 / h;
[0089] Cl2 feed amount: 10.0Nm 3 / h;
[0090] 1,1,2-TCE liquid phase circulation volume: 7.1m 3 / h;
[0091] Empty pipe liquid speed: 0.55m / s;
[0092] Dwell time: 9.1s;
[0093] Reaction temperature: 41-45℃.
[0094] The first mixing device and the second mixing device used are both Venturi-type jet reactors, and the third mixing device is a pipeline containing an SL-type static mixing component.
[0095] Reaction results:
[0096] The VCM conversion was 93.0%, and the 1,1,2-TCE selectivity was 92.0%.
[0097] Comparative Example 2
[0098] The experimental process, method and process conditions used in this example are the same as those in Comparative Example 1, except that the 1,1,2-TCE liquid phase circulation volume is 4.3 m 3 / h.
[0099] Reaction results:
[0100] The VCM conversion was 89.3% and the 1,1,2-TCE selectivity was 90.1%.
[0101] Comparative Example 3
[0102] The experimental process, method and process conditions used in this example are the same as those in Comparative Example 1, except that the Cl2 feed amount is 11.5 Nm 3 / h.
[0103] Reaction results:
[0104] The VCM conversion was 93.8% and the 1,1,2-TCE selectivity was 89.3%.
[0105] Comparative Example 4
[0106] The experimental process, method and process conditions used in this example are the same as those in Comparative Example 1, with the only difference being that the first mixing device is a double-nozzle opposed impinging stream reactor.
[0107] Reaction results:
[0108] The VCM conversion was 92.7% and the 1,1,2-TCE selectivity was 92.2%.
[0109] Comparative Example 5
[0110] The experimental process, method and process conditions used in this example are the same as those in Comparative Example 1, with the only difference being that the third mixing device is a pipeline containing an SK-type static mixing component.
[0111] Reaction results:
[0112] The VCM conversion was 93.4% and the 1,1,2-TCE selectivity was 92.6%.
[0113] Comparative Example 6
[0114] The experimental process, method and process conditions used in this example are the same as those in Comparative Example 1, with the only difference being that the third mixing device is a pipeline containing an SH-type static mixing component.
[0115] Reaction results:
[0116] The VCM conversion was 95.4% and the 1,1,2-TCE selectivity was 93.0%.
[0117] Comparative Example 7
[0118] The experimental process, method and process conditions used in this example are the same as those in Comparative Example 1, with the only difference being that the third mixing device is a pipeline containing an SX-type static mixing component.
[0119] Reaction results:
[0120] The VCM conversion was 97.3% and the 1,1,2-TCE selectivity was 94.6%.
[0121] Comparative Example 8
[0122] The experimental process, method and process conditions used in this example are the same as those in Comparative Example 1, with the only difference being that the third mixing device is a pipeline containing a SV-type static mixing component.
[0123] Reaction results:
[0124] The VCM conversion was 98.1% and the 1,1,2-TCE selectivity was 95.9%.
[0125] Comparative Example 9
[0126] The experimental process, method and process conditions used in this example are the same as those in Comparative Example 8, with the only difference being that the second mixing device is composed of a Venturi-type jet reactor and a pipeline containing an SV-type static mixing component, wherein the Venturi jet reactor is in front of the pipeline containing the SV-type static mixing component.
[0127] Reaction results:
[0128] The VCM conversion was 98.9% and the 1,1,2-TCE selectivity was 96.8%.
[0129] Comparative Example 10
[0130] The experimental process, method and process conditions used in this example are the same as those in Comparative Example 8, the only difference being the Cl2 feeding method. In this example, Cl2 enters the reaction system from inlet 2.2.
[0131] Reaction results:
[0132] The VCM conversion was 98.4% and the 1,1,2-TCE selectivity was 96.5%.
[0133] Comparative Example 11
[0134] The experimental process, method and process conditions used in this example are the same as those in Comparative Example 10, with the only difference being that the second mixing device consists of a Venturi-type jet reactor and a double-nozzle opposed impinging stream reactor, wherein the Venturi jet reactor is in front of the double-nozzle opposed impinging stream reactor.
[0135] Reaction results:
[0136] The VCM conversion was 97.6% and the 1,1,2-TCE selectivity was 94.1%.
[0137] Comparative Example 12
[0138] The experimental process, method and process conditions used in this example are the same as those in Comparative Example 9, the only difference being the Cl2 feeding method. In this example, Cl2 enters the reaction system from inlet 2.3.
[0139] Reaction results:
[0140] The VCM conversion was 99.1% and the 1,1,2-TCE selectivity was 97.2%.
[0141] Example 13
[0142] The experimental process, method and process conditions used in this example are the same as those in Comparative Example 9, with the only difference being the Cl2 feeding method. In this example, Cl2 is fed in stages, with 20% of Cl2 entering the reaction system from inlet 2.1, 30% of Cl2 being injected from inlet 2.2, 30% of Cl2 being injected from inlet 2.3, and the remaining 20% of Cl2 entering from inlet 3.1.
[0143] Reaction results:
[0144] The VCM conversion was 99.5% and the 1,1,2-TCE selectivity was 98.1%.
[0145] Embodiment 14
[0146] The experimental process, method and process conditions used in this example are the same as those in Example 13, with the only difference being that the second mixing device is composed of a pipeline containing an SV-type static mixing component and a double-nozzle opposed impinging flow reactor, wherein the pipeline containing the SV-type static mixing component is in front of the double-nozzle opposed impinging flow reactor.
[0147] Reaction results:
[0148] The VCM conversion rate was 99.6% and the 1,1,2-TCE selectivity was 98.9%.
[0149] Embodiment 15
[0150] The experimental process, method and process conditions used in this example are the same as those in Example 14, with the only difference being that the third mixing device is composed of a pipeline containing an SV type static mixing component and a pipeline containing an SH type static mixing component alternately connected (specifically, the direction of the material in the third mixing device is: first passing through the pipeline containing the SV type static mixing component, then passing through the pipeline containing the SH type static mixing component, then passing through the pipeline containing the SV type static mixing component, and finally passing through the pipeline containing the SH type static mixing component).
[0151] Reaction results:
[0152] The VCM conversion rate was 99.8%, and the 1,1,2-TCE selectivity was 99.5%.
[0153] Comparative Example 16
[0154] The experimental process, method and process conditions used in this example are the same as those in Example 15, with the only difference being that the third mixing device is composed of two pipes connected to each other containing SK type static mixing components.
[0155] Reaction results:
[0156] The VCM conversion was 96.1% and the 1,1,2-TCE selectivity was 94.5%.
Claims
1. A method for preparing 1,1,2-trichloroethane, the method comprising the steps of: Vinyl chloride and circulating medium 1,1,2-trichloroethane are mixed in the first mixing device, and then enter the second mixing device and the third mixing device in sequence to react with chlorine to generate 1,1,2-trichloroethane; A portion of the reaction product 1,1,2-trichloroethane is sent to the first mixing device as a circulating medium, and the remaining reaction products enter the subsequent purification process. in, The second mixing device comprises at least a first section and a second section, wherein the first section is a jet reactor and / or an impinging stream reactor; and the second section is a pipeline reactor having an SV type static mixing member. The third mixing device comprises at least one pipeline reactor of SL type, SV type and / or SH type static mixing member, At least the second mixing device, the third mixing device and a chlorine gas inlet are provided between the second mixing device and the third mixing device.
2. The method of claim 1, wherein: The first mixing device is a jet reactor, an impinging stream reactor, a reaction pipe equipped with a static mixing member, or a combination thereof; Preferably, the jet reactor is a jet pump, a venturi reactor or a combination thereof; Preferably, the impinging stream reactor is a multi-nozzle impinging stream reactor, such as a double-nozzle opposed impinging stream reactor; Preferably, the reaction pipe equipped with a static mixing component may be a reaction pipe having a mixing component of SV type, SK type, SX type, SL type, SH type and a combination thereof.
3. The method of claim 1, wherein: The second mixing device has three or four sections; Preferably, the third section or the fourth section in the second mixing device is a jet reactor, an impinging stream reactor, a reaction pipe equipped with a static mixing member, or a combination thereof.
4. The method of claim 1, wherein: The second mixing device has at least one chlorine gas inlet (e.g., one, two, three or four chlorine gas inlets); Preferably, the chlorine inlet is in any section of the second mixing device; Preferably, each section of the second mixing device has a chlorine inlet. Preferably, the second mixing device has two sections, wherein the first section is a jet reactor (eg, a Venturi reactor) or an impinging stream reactor (eg, a double-nozzle opposed impinging stream reactor), and the second section is a pipeline reactor having a SV type static mixing member.
5. The method of claim 1, wherein: The third mixing device has at least one section, such as one section, two sections, three sections, four sections or five sections; Preferably, except for at least one section of a pipeline reactor having a SL-type, SV-type and / or SH-type static mixing member, each section of the third mixing device may be a jet reactor, an impinging stream reactor, a reaction pipeline equipped with a static mixing member, or a combination thereof; Preferably, the segments of the third mixing device are connected in series, and the order of connection can be arranged in any order; Preferably, the third mixing device has a section comprising a pipeline reactor of SL-type, SV-type and / or SH-type static mixing members (e.g. a pipeline reactor with SL-type static mixing members); Preferably, the third mixing device has two sections, wherein the first section is a pipeline reactor with SL type, SV type and / or SH type static mixing components (for example, a pipeline reactor with SV type static mixing components), and the second section includes a pipeline reactor with SL type, SV type and / or SH type static mixing components (for example, a pipeline reactor with SH type static mixing components).
6. The method of claim 1, wherein: A chlorine gas inlet is provided between the second mixing device and the third mixing device.
7. The method of claim 1, wherein: The third mixing device has at least one chlorine gas inlet (e.g., one, two, three or four chlorine gas inlets); Preferably, the chlorine inlet is in any section of the third mixing device; Preferably, each section of the third mixing device has a chlorine gas inlet.
8. The method of claim 1, wherein: The process conditions of the method are as follows: VCM airspeed 0.01-0.33s -1 , preferably 0.01-0.20s -1 ; Liquid phase circulation volume (1,1,2-TCE liquid phase volume m 3 : VCM feed amount Nm 3 ) is greater than 0.57, preferably greater than 0.60, more preferably greater than 0.68, for example 0.57-1.5; The empty tube liquid velocity (referring to the ratio of the volume flow rate of 1,1,2-TCE to the cross-sectional area of the static mixing pipe reactor) is greater than 0.3 m / s, preferably greater than 0.48 m / s, for example 0.3-1.0 m / s; Reaction temperature 30-95°C, preferably 38-82°C; Cl2: VCM (molar ratio) is 0.86-1.20, preferably 0.90-1.10, more preferably 0.93-1.06; The residence time is greater than 6.0 s, for example 6-15 s.
9. The method of claim 1, wherein: Chlorine is introduced into the chlorine inlet of the second mixing device and the chlorine inlet after the second mixing device (including the chlorine inlet between the second mixing device and the third mixing device and the chlorine inlet of the third mixing device) in the following ratio: (20-80): (80-20), preferably (30-70): (70-30), more preferably (40-60): (60-40); Preferably, if the second mixing device has two or more chlorine inlets (e.g., two, three or four chlorine inlets), each chlorine inlet may be fed with chlorine in the same or different amounts; Preferably, the second mixing device has two chlorine inlets, and the ratio of chlorine introduced into each chlorine inlet is (20-80): (80-20), preferably (30-70): (70-30), and more preferably (30-50): (50-80); Preferably, the chlorine inlet between the second mixing device and the third mixing device and the chlorine inlet of the third mixing device can be fed with chlorine in the same or different amounts; Preferably, the ratio of chlorine introduced into the chlorine inlet between the second mixing device and the third mixing device and the chlorine inlet of the third mixing device is (20-80): (80-20), preferably (30-70): (70-30), and more preferably (30-50): (50-80); Preferably, if the third mixing device has two or more chlorine inlets (eg, two, three or four chlorine inlets), the chlorine inlets may be fed with the same or different amounts of chlorine.
10. A device for preparing 1,1,2-trichloroethane, the device comprising: a first mixing device having a vinyl chloride inlet and a circulating medium inlet, a second mixing device, and The third mixing device, The second mixing device comprises at least a first section and a second section, wherein the first section is a jet reactor and / or an impinging stream reactor; and the second section is a pipeline reactor having an SV type static mixing member. The third mixing device comprises at least one pipeline reactor of SL type, SV type and / or SH type static mixing member, At least the second mixing device, the third mixing device and a chlorine gas inlet are provided between the second mixing device and the third mixing device.