Device for continuously producing 1, 1, 1, 3-tetrachloropropane

Abstract

The utility model relates to a device for continuously producing 1, 1, 1, 3-tetrachloropropane, which adopts a loop reactor in which a beam pipe is arranged, reaction raw materials ethylene and carbon tetrachloride are mixed at a venturi nozzle at the lower part of the reactor through a gas circulation loop and a liquid circulation loop outside the reactor, and then the mixture is fed into the reactor. And spraying into a reactor filled with a main catalyst. Reaction raw materials are circularly stirred under the action of a beam pipe in the reactor, so that solid, liquid and gas phases are fully mixed. According to the utility model, the gas raw material circulation loop and the liquid raw material circulation loop are adopted for double-circulation mixed reaction, so that the reaction conversion rate and selectivity can be improved, and industrial continuous production can be well realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of device for the continuous production of 1,1,1,3-tetrachloropropane belongs to chemical technology field. BACKGROUND

[0002] 1,1,1,3-tetrachloropropane is an important fine chemical, is the key raw material of synthesis trichloropropene, trifluoropropene, itself is also good degreasing agent, paint remover and solvent. Carbon tetrachloride is the byproduct of methane chlorination device, according to the Montreal Protocol, except raw material use, reagent use and special exemption use, completely stop the production and consumption of carbon tetrachloride. Therefore, carbon tetrachloride is utilized comprehensively, such as being synthesized into tetrachloropropane, which has very important practical significance.

[0003] 1,1,1,3-tetrachloropropane is mainly synthesized by ethylene and carbon tetrachloride in industry:

[0004] CH2=CH2+CCl4→CCl3-CH2-CH2Cl

[0005] Traditional industrial production mode uses iron as main catalyst, uses ferric chloride and phosphate ester compound as cocatalyst, adopts kettle type batch reactor. In kettle type reactor, mixing of reactants is carried out by stirring paddle stirring mode, and the mixing efficiency is limited, which is easy to cause local ethylene self-polymerization, generate more 1,1,1,5-tetrachloropentane and 1,3,3,5-tetrachloropentane and other byproducts, and the product selectivity is low, generally 1,1,1,3-tetrachloropropane selectivity is below 90%, and a large amount of heavy substance is produced at the same time, causing great waste of resources; the kettle type reactor has high energy consumption and low reaction efficiency due to repeated temperature rising and falling operation. Chinese patent CN111056913A discloses a method for continuously producing 1,1,1,3-tetrachloropropane, which uses metal iron or supported iron as main catalyst, uses phosphate ester or phosphite ester as cocatalyst, and adopts fixed bed reactor, which is claimed to be capable of continuously producing 1,1,1,3-tetrachloropropane. Chinese patent CN114605226A discloses a method for continuously producing 1,1,1,3-tetrachloropropane, which uses metal iron or supported iron as main catalyst, uses phosphate ester, phosphite ester or formamide small molecule organic amine as cocatalyst, and adopts fixed bed reactor, and the feeding mode can be gas-liquid co-current or gas-liquid cross flow, which is claimed to be capable of continuously producing 1,1,1,3-tetrachloropropane.

[0006] However, the above method can realize the continuous production of 1,1,1,3-tetrachloropropane, but due to the use of fixed bed reactor, the problem of phosphate deposition on the surface of solid catalyst still exists, and the stability of the activity of the catalyst has not been completely solved, and long-term continuous production reaction cannot be carried out. Moreover, when using fixed bed for continuous production, the main catalyst needs to be replaced frequently after being consumed, which increases the complexity of operation, and further improvement is necessary.

[0007] In addition, CN116850900A discloses a continuous loop reactor for gas-liquid-solid three-phase reaction and a three-phase reaction method, however, the internal material of the loop reactor cannot be fully mixed and dispersed. It is not conducive to improve the conversion rate and selectivity. SUMMARY

[0008] In view of the above-mentioned prior art, the inventors of the present application have made in-depth and extensive research in the field of 1,1,1,3-tetrachloropropane synthesis, and found that the use of gas raw material circulation loop and liquid raw material circulation loop double circulation mixed reaction, and the setting of two layers of beam pipes in the reactor can greatly promote the mixing and separation of gas-liquid two phases in the reactor, not only can improve the reaction conversion rate and selectivity, but also realize the continuous production of industrialization. The present application is completed based on the above-mentioned findings.

[0009] Therefore, the purpose of the present application is to provide a device for continuous production of 1,1,1,3-tetrachloropropane, which sets a gas circulation loop and a liquid circulation loop outside the reactor, and sets a venturi nozzle to mix raw materials at the bottom of the reactor, and sets two layers of beam pipes in the reactor to greatly promote the mixing and separation of gas-liquid two phases in the reactor.

[0010] The technical scheme for achieving the above-mentioned purpose can be summarized as follows:

[0011] The device for continuous production of 1,1,1,3-tetrachloropropane comprises a reactor provided with a beam pipe inside, a feeding port and a gas one-way valve are arranged at the upper part of the reactor, a venturi nozzle is arranged at the bottom of the reactor, a condenser provided with a discharge port is connected at the middle part of the reactor, the gas one-way valve is connected with an ethylene feeding port and connected with the venturi nozzle through an ethylene circulation loop, and the venturi nozzle is further connected with a feeding pump through a circulating pump and connected with the middle part of the reactor through a carbon tetrachloride liquid circulation loop.

[0012] According to the present application, preferably, the reactor is a column reactor.

[0013] According to the present application, preferably, the bottom of the reactor is conical.

[0014] According to the present application, preferably, the beam pipe is arranged in a vertical direction.

[0015] According to the utility model, preferably, the beam tube is provided with two or more layers, and more preferably 2-5 layers.

[0016] The utility model discloses the following beneficial effects:

[0017] 1. The reactor of the utility model is internally provided with a beam tube, which can greatly promote the mixing and separation of gas-liquid two-phase in the reactor, and is beneficial to improving the reaction conversion rate and selectivity.

[0018] 2. The utility model adopts double-circulation mixed reaction of gas raw material circulation loop and liquid raw material circulation loop, which can not only improve the reaction conversion rate and selectivity, but also can realize the continuous production of industrialization well.

[0019] 3. When the utility model is used, the main catalyst does not need to be taken out from the reactor after use, and is recycled until completely consumed, thereby reducing the use cost of the catalyst.

[0020] 4. The utility model can realize continuous production without additional operation, significantly simplifies the operation process, has long continuous production time, and the reactor does not need to be cleaned after use and can be reused. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The utility model discloses a device main body structure schematic diagram for continuous production 1,1,1,3 - tetra chloropropane.

[0022] Wherein: 1, ethylene feed inlet, 2, gas check valve, 3, ethylene circulation loop, 4, condenser, 5, venturi nozzle, 6, discharge port, 7, carbon tetrachloride liquid circulation loop, 8, beam tube, 9, circulating pump, 10, feed pump, 11, feeding port, 12, reactor. DETAILED DESCRIPTION

[0023] As Figure 1 shown, the device for continuous production 1,1,1,3 - tetra chloropropane of the utility model, including the reactor 12 that is internally provided with the beam tube 8, the reactor 12 upper portion is provided with the feeding port 11 and gas check valve 2, the reactor 12 bottom is provided with venturi nozzle 5, the condenser 4 of discharge port 6 is connected and arranged in the middle of the reactor 12, the gas check valve 2 is connected with ethylene feed inlet 1 and is connected venturi nozzle 5 through ethylene circulation loop 3, the venturi nozzle 5 still is connected with feed pump 10 through circulating pump 9 and is connected with the middle part of reactor 12 through carbon tetrachloride liquid circulation loop 7.

[0024] In one or more preferred embodiments, the material of the reactor 12 is carbon steel material. The reactor 12 is a column reactor, and the bottom of the reactor 12 is conically arranged.

[0025] In one or more preferred embodiments, the beam tube 8 is arranged in a vertical direction; preferably, the beam tube 8 is arranged with two or more layers, further preferably 3-5 layers.

[0026] The utility model uses, through feeding port 11 to join carbon tetrachloride, main catalyst and cocatalyst, chelating agent in reactor 12, start circulating pump 9, liquid forms circulation loop after passing in ethylene by ethylene feed port 1 and heating temperature rise, the unreacted ethylene is reentered reactor 12 bottom by gas one-way valve 2, gas circulation loop 3 and venturi nozzle 5 from reactor 12 upper part, the unreacted carbon tetrachloride is reentered reactor 12 bottom by carbon tetrachloride liquid circulation loop 7, circulating pump 9 and venturi nozzle 5 from reactor 12 middle part, when the carbon tetrachloride conversion rate in reactor 12 is between 70%-85%, simultaneously open feed pump 10 and discharge port 6, and feed pump 10 pumps in the mixed solution of carbon tetrachloride, cocatalyst and chelating agent to carry out continuous production, and 1,1,1,3-tetrachloropropane crude product is condensed from discharge port 6 after condenser 4.

[0027] The inventive concept of the utility model lies in:

[0028] The reaction raw materials ethylene and carbon tetrachloride are mixed at the venturi nozzle 5 at the bottom of the reactor 12 through the gas circulation loop 3 and the carbon tetrachloride liquid circulation loop 7 outside the reactor 12, and then enter the inside of the reactor 12 filled with solid main catalyst, and the beam tube 8 is arranged in the reactor 12 to strengthen the contact of materials.

[0029] The utility model will be further described below in combination with specific implementation cases, but will not limit the utility model to these specific implementation manners.

[0030] Example 1

[0031] As Figure 1As shown, a device for continuously producing 1,1,1,3-tetrachloropropane includes a reactor 12 with a beam tube 8 inside, a feeding port 11 and a gas one-way valve 2 at the upper part of the reactor 12, a Venturi nozzle 5 at the bottom of the reactor 12, a condenser 4 with a discharge port 6 connected at the middle part of the reactor 12, the gas one-way valve 2 being connected with an ethylene feeding port 1 and the Venturi nozzle 5 through an ethylene circulation loop 3, the Venturi nozzle 5 being further connected with a feeding pump 10 through a circulation pump 9 and connected with the middle part of the reactor 12 through a carbon tetrachloride liquid circulation loop 7.

[0032] In this embodiment, the material of the reactor 12 is carbon steel, the reactor 12 is a column reactor, and the bottom of the reactor 12 is conical. The beam tube 8 is arranged in the vertical direction, and the beam tube 8 is provided with two layers.

[0033] The device of this embodiment is used to continuously produce 1,1,1,3-tetrachloropropane, including the following steps:

[0034] (1) Prepare a catalyst, mix 100 g of ferric chloride with 300 g of tributyl phosphate to form a complex as a catalyst;

[0035] (2) Put 40 kg of carbon tetrachloride, 1 kg of iron sand, 400 g of catalyst, and 40 g of EDTA into the reactor 12, and after closing the reactor 12, perform vacuumizing treatment;

[0036] (3) Start the loop circulation of the reactor 12, the circulation time is 30 seconds, and the reactor 12 is preheated,

[0037] (4) Introduce ethylene to start the reaction, control the temperature of the reactor 12 to be 105-115℃, and control the pressure in the reactor 12 to be 0.65 MPa;

[0038] (5) After 2 hours, monitor the conversion rate of carbon tetrachloride in the reactor 12 to reach 75%, open the feeding pump 10 to pump in a mixed solution of carbon tetrachloride and catalyst and chelating agent in a ratio of 100:1:0.1, and at the same time control the feeding ratio of carbon tetrachloride and ethylene to be 10:1. Open the discharge port 6 to collect the crude tetrachloropropane. The residence time of carbon tetrachloride reaction is maintained for 2 hours.

[0039] (6) Continuously produce for 500 hours, monitor the reaction pressure, and take samples for detection every hour.

[0040] The pressure in the reactor 12 is 0.50-0.55 MPa, and the sample is analyzed by gas chromatography, and the results are that the average conversion rate of the raw material ethylene is 99.6%, the average conversion rate of carbon tetrachloride is 75.3%, the selectivity of 1,1,1,3-tetrachloropropane is 97.9%, and the purity of 1,1,1,3-tetrachloropropane prepared after rectification is greater than 99.95%.

[0041] Compared with the traditional loop reactor, the two layers of beam tubes 8 can greatly promote the mixing and separation of the gas-liquid two-phase in the reactor 12, and the continuous production effect of the reactor 12 is further enhanced. The residence time of ethylene gas under single circulation is increased, and the conversion rate of the raw material ethylene is greatly improved.

Claims

1. An apparatus for the continuous production of 1,1,1,3-tetrachloropropane, characterized in that The device comprises a reactor (12) with a beam tube (8) inside, a feeding port (11) and a gas one-way valve (2) arranged on the upper part of the reactor (12), a Venturi nozzle (5) arranged at the bottom of the reactor (12), a condenser (4) with a discharging port (6) connected to the middle part of the reactor (12), the gas one-way valve (2) is connected with an ethylene feeding port (1) and the Venturi nozzle (5) through an ethylene circulating loop (3), the Venturi nozzle (5) is further connected with a feeding pump (10) through a circulating pump (9) and connected with the middle part of the reactor (12) through a carbon tetrachloride liquid circulating loop (7).

2. The apparatus for continuously producing 1,1,1,3-tetrachloropropane according to claim 1, characterized by, The reactor (12) is a column reactor.

3. The apparatus for continuously producing 1,1,1,3-tetrachloropropane according to claim 1, characterized by, The bottom of the reactor (12) is conical.

4. The apparatus for continuously producing 1,1,1,3-tetrachloropropane according to any one of claims 1 to 3, characterized in that, The beam tube (8) is arranged in a vertical direction.

5. The apparatus for continuously producing 1,1,1,3-tetrachloropropane according to claim 4, characterized by, The beam tube (8) is provided with two or more layers.

6. The apparatus for continuously producing 1,1,1,3-tetrachloropropane according to claim 5, characterized by, The beam tube (8) is provided with 2-5 layers.

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