CN114452915A - Method and device for continuously synthesizing pentachloroethane by using trichloroethylene as raw material - Google Patents
Method and device for continuously synthesizing pentachloroethane by using trichloroethylene as raw material Download PDFInfo
- Publication number
- CN114452915A CN114452915A CN202111444162.0A CN202111444162A CN114452915A CN 114452915 A CN114452915 A CN 114452915A CN 202111444162 A CN202111444162 A CN 202111444162A CN 114452915 A CN114452915 A CN 114452915A
- Authority
- CN
- China
- Prior art keywords
- pipeline
- raw material
- gas
- reaction
- reactor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/0093—Microreactors, e.g. miniaturised or microfabricated reactors
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
- B01J19/12—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electromagnetic waves
- B01J19/122—Incoherent waves
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C17/00—Preparation of halogenated hydrocarbons
- C07C17/013—Preparation of halogenated hydrocarbons by addition of halogens
- C07C17/02—Preparation of halogenated hydrocarbons by addition of halogens to unsaturated hydrocarbons
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Health & Medical Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Toxicology (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention belongs to the technical field of chemical engineering, and relates to a method and a device for continuously synthesizing pentachloroethane by using trichloroethylene as a raw material. Firstly, introducing dried nitrogen into a micro-channel reactor in the device; then, dehydrating the chlorine gas through a mass flow controller and a dryer and introducing the chlorine gas into a reactor system; then pumping the raw material liquid containing trichloroethylene into a microchannel reactor, leading the raw material liquid and the introduced chlorine gas to be fully and uniformly mixed in the microchannel reactor, continuously carrying out continuous chlorination addition reaction on the mixed gas-liquid mixture in a delay pipeline under the action of illumination, and processing the liquid phase product after the reaction to obtain the high-yield pentachloroethane. The invention adopts a continuous process to replace the traditional intermittent method for carrying out chlorination reaction to synthesize pentachloroethane, enhances the mass transfer capacity of gas-liquid reaction, greatly shortens the reaction time, improves the reaction efficiency and makes up the defect of insufficient mixing of gas-phase homogeneous reaction.
Description
Technical Field
The invention belongs to the technical field of chemical industry, and relates to a method for producing pentachloroethane, in particular to a method and a device for synthesizing pentachloroethane by using a microchannel continuous technology and taking trichloroethylene as a raw material.
Background
Most of the traditional refrigerants are chlorinated alkanes (CF) containing chlorine2Cl2、CHF2Cl, R502, etc.), chlorine-containing halogenated hydrocarbons in the atmosphere are decomposed by irradiation with ultraviolet rays to generate molecular chlorine, which causes a problem of ozone layer destruction. With the enhancement of environmental protection and survival consciousness of countries in the world, work for protecting the atmosphere and searching for an Ozone Depletion Substance (ODS) substitute has been gradually carried out. The ozone depletion potential of chlorine-free hydrofluorocarbons is 0, such as R125 refrigerant (pentafluoroethane), R-134a (1, 1, 1, 2-tetrafluoroethane), R32 (difluoromethane). Among them, R125 and R-134a are good substitutes and are often used as mixed refrigerants. Pentafluoroethane is mainly obtained by fluorination reaction of pentachloroethane. Large-scale synthesis of pentachloroethane becomes critical as an important fluorinated hydrocarbon intermediate.
There are many methods for synthesizing pentachloroethane, mainly dichloroethane chlorination method, vinylidene chloride method, acetylene method and trichloroethylene method. For example, patent CN102267863B uses dichloroethane as raw material, and makes it produce substitution reaction with chlorine gas whose equivalent ratio is 2-3.2 times, and the reaction process produces trichloro/tetrachloro/pentachloro/hexachloroethane mixture and hydrogen chloride. The reaction degree is controlled by adjusting the introduction amount of chlorine gas, and the required tetrachloro/pentachloroethane mixture is obtained. In the process, hydrogen chloride is absorbed by water, and finally the product pentachloroethane is obtained by adopting a rectification mode. In patent CN102295518B, vinylidene chloride is used as a raw material in the first step, and is subjected to an addition reaction with chlorine gas under the action of a catalyst such as ferric chloride and cesium chloride, and the reaction temperature is maintained at 70 ℃ for 15 hours to obtain tetrachloroethane. Then, in the second stage reaction, the tetrachloroethane and chlorine gas are subjected to substitution reaction for 21 h. Finally obtaining the final product pentachloroethane through alkali washing and rectification processes. Patent CN108546228B states that the use of a molar ratio of 1: 3, under the catalytic action of metal halide and at the reaction temperature of 120 ℃, the pentachloroethane with the yield of 60 percent is obtained through addition reaction. As described in Chinese patent CN100338001C, the pentachloroethane is obtained by using trichloroethylene as a raw material, continuously introducing chlorine gas under the action of an anhydrous ferric trichloride catalyst, and keeping the chlorine gas at a reaction temperature of 70-90 ℃ for several hours. As also described in patent CN101265154B, under uv irradiation, trichloroethylene and chlorine were mixed in a ratio of 1: 1-1.5, at 50-150 deg.c, and through addition reaction in a quartz tube reactor, pentachloroethane with high purity and high yield may be produced.
The existing technology for synthesizing pentachloroethane mostly obtains a target product in an intermittent mode by changing different reaction raw materials to react with chlorine and regulating and controlling a reaction process. Among them, the dichloroethane chlorination method belongs to the radical chlorination process, and has the problems of low reaction selectivity, complex synthetic product and difficult post-treatment process. The vinylidene chloride method and the acetylene method are faced with the phenomena of complex reaction process, harsh reaction conditions and low yield. In contrast, the addition reaction mode of the trichloroethylene method has more synthetic advantages compared with the free radical substitution chlorination mode. But has the defects of slow reaction rate, complex reaction equipment and low safety and controllability.
Disclosure of Invention
The invention aims to provide a continuous method and a device for synthesizing pentachloroethane by using micro-channel continuous chlorination reaction by using trichloroethylene as a raw material aiming at the defects of a technology for synthesizing pentachloroethane in a batch mode.
In order to achieve the purpose, the invention adopts the technical scheme that:
a device for continuously synthesizing pentachloroethane by taking trichloroethylene as a raw material comprises a chlorine gas cylinder 1, a raw material tank 2, a metering pump 3, a preheating pipeline 4, a microchannel reactor 5, a gas mass flow meter 6, a nitrogen gas cylinder 7, a sampling valve 8, a light source 9, a delay pipeline 10, a back pressure valve 11 and a storage tank 12; the micro-reactor 5 is provided with two feeding ports and a discharging port, and the raw material tank 2 is connected with one feeding port of the micro-channel reactor 5 through a first pipeline; the chlorine gas cylinder 1 is connected with the other feeding port of the microchannel reactor 5 through a second pipeline; and the discharge port of the micro-channel reactor 5, the delay pipeline 10, the backpressure valve 11 and the storage tank 12 are sequentially connected in series through pipelines.
An input pump 3 and a preheating pipeline 4 are arranged on a first pipeline between the raw material tank 2 and the microchannel reactor 5, the input pump 3 is used for inputting raw materials into the microchannel reactor 5, a chlorine mass flow meter 6 is arranged between the microchannel reactor 5 and the chlorine gas bottle 1, and a pressure sensor and a temperature sensor are arranged between the microchannel reactor 5 and the chlorine mass flow meter 6; meanwhile, a pressure sensor and a temperature sensor are arranged between the micro-channel reactor 5 and the delay pipeline 10, and the tail end of the delay pipeline is provided with the temperature sensor for detecting pressure changes before and after chlorination reaction and monitoring reaction temperature.
A chlorine gas inlet control valve, a gas flowmeter for detecting the gas flow and a gas inlet pressure gauge for detecting the gas pressure condition are arranged between the second pipeline chlorine gas bottle 1 and the microchannel reactor 5; a three-way valve is arranged between the chlorine gas cylinder 1 and the chlorine gas mass flowmeter 6 in the second pipeline, the three-way valve is connected with the outlet of the nitrogen gas cylinder 7 through a third pipeline, and a gas inlet control valve and a gas inlet pressure gauge are arranged on the pipeline; the tail ends of the micro-channel reactor 5 and the delay pipeline 10 are respectively provided with a sampling port; and a back pressure valve 11 is arranged at the tail end of the delay pipeline.
And a gas dryer (for drying chlorine and nitrogen) is arranged between the three-way valve arranged on the second pipeline and the gas mass flowmeter 6.
And the tail ends of the micro-channel reactor and the delay pipeline are respectively provided with a sampling port for sampling and analyzing the reaction state. The delay line may be not only one stage but also two or more stages. And the tail end of the delay pipeline is provided with a back pressure valve for carrying out back pressure on the reaction system, enhancing mass transfer and accelerating the reaction speed.
A method for continuously synthesizing pentachloroethane by using trichloroethylene as a raw material by using the device comprises the following steps of firstly introducing dried nitrogen into a microchannel reactor 5; then, dehydrating the chlorine gas through a mass flow controller and a dryer and introducing the chlorine gas into a reactor system; then pumping the raw material liquid containing trichloroethylene into a microchannel reactor, leading the raw material liquid and the introduced chlorine gas to be fully and uniformly mixed in the microchannel reactor, continuously carrying out continuous chlorination addition reaction on the mixed gas-liquid mixture in a delay pipeline under the action of illumination, and processing the liquid phase product after the reaction to obtain the high-yield pentachloroethane.
The raw material liquid containing trichloroethylene is prepared by dissolving trichloroethylene in a solvent, and adding a polymerization inhibitor with the mass of 0.05-0.5% of the dissolved liquid; the content of trichloroethylene in the raw material liquid is 10 wt% -70 wt%; the solvent is one or more of dichloromethane, methanol and diethyl ether.
The molar flow ratio of the trichloroethylene to the chlorine in the gas-liquid two phases introduced into the reactor is controlled to be 1:0.9-1:1.5, preferably 1:1.05-1: 1.1; the gas inlet pressure of the chlorine is 0.05-0.7MPa, preferably 0.1-0.3 MPa.
The temperature of the raw material liquid in the preheating pipeline is 20-80 ℃, and the temperature in the microchannel reactor and the delay pipeline is 20-90 ℃, preferably 30-50 ℃.
The residence time of the reaction solution in the delay line (10) can be controlled to be 20 to 480s, preferably 60 to 480 s.
The light source can be one or more of ultraviolet light, xenon (mercury) light source and LED lamp, and the reaction generation condition and reaction rate can be regulated and controlled by adjusting the illumination intensity.
The reaction principle of the invention is as follows:
the invention removes oxygen and water from raw materials, adds polymerization inhibitor to prevent side reaction, and completes chlorination addition reaction of trichloroethylene to generate pentachloroethane under the high-efficiency mass transfer action of pretreated raw material liquid and dry chlorine gas in a microchannel continuous device at low temperature (30-50 ℃).
The invention has the advantages and positive effects that:
1. the invention utilizes a continuous chlorination device, takes trichloroethylene and chlorine as raw materials, and carries out the pretreatment process of removing water and oxygen from the raw materials, and the low-temperature development of gas-liquid continuous addition reaction is carried out to synthesize pentachloroethane, thereby greatly reducing the occurrence of side reactions, leading the yield of the final product to reach 98.3 percent and the selectivity of the product to reach 99.2 percent.
2. The invention adopts a continuous process to replace the traditional intermittent method for carrying out chlorination reaction to synthesize pentachloroethane, enhances the mass transfer capacity of gas-liquid reaction, greatly shortens the reaction time, improves the reaction efficiency and makes up the defect of insufficient mixing of gas-phase homogeneous reaction. The reaction safety is ensured to a certain extent by reducing the reaction temperature. The device achieves the effects of accurate temperature control, rapid reaction heat removal and controllable reaction process while achieving the miniaturization of the device.
3. The invention realizes photochemical chlorination addition reaction by utilizing a continuous device, has the characteristics of uniform and continuous irradiation and strong light transmittance, improves the original harsh reaction conditions, and ensures high selectivity and high yield of the reaction on the basis of reducing the reaction temperature and the system pressure.
4. The one-way valve, the chlorine flowmeter, the microchannel reactor, the delay pipeline and the gas-liquid separation tank used in the reaction device are all made of polytetrafluoroethylene materials or sprayed with polytetrafluoroethylene materials lined inside, so that the method has the characteristics of high solvent resistance and corrosion resistance, and the intrinsic safety of the chlorination addition reaction is improved.
Description of the drawings:
FIG. 1: the device of the invention.
Detailed Description
The invention is described in further detail below with reference to the accompanying drawings.
The invention uses trichloroethylene as a starting material, uses chlorine as a chlorinating agent, and uses a microchannel continuous device to synthesize the important raw material pentachloroethane of the pentafluoroethane under the condition of illumination. The product purity is high while high selectivity and high yield are ensured, so that the synthesis process of the pentachloroethane is more efficient and safer.
Example 1
The device is shown in figure 1, and the device for continuously synthesizing pentachloroethane by taking dichloroethane as a raw material comprises a chlorine gas cylinder 1, a raw material tank 2, a metering pump 3, a preheating pipeline 4, a microchannel reactor 5, a gas mass flowmeter 6, a nitrogen gas cylinder 7, a sampling valve 8, a light source 9, a delay pipeline 10, a backpressure valve 11 and a storage tank 12; the micro-reactor 5 is provided with two feeding ports and a discharging port, and the raw material tank 2 is connected with one feeding port of the micro-channel reactor 5 through a first pipeline; the chlorine gas cylinder 1 is connected with the other feeding port of the microchannel reactor 5 through a second pipeline; and the discharge port of the micro-channel reactor 5, the delay pipeline 10, the backpressure valve 11 and the storage tank 12 are sequentially connected in series through pipelines.
An input pump 3 and a preheating pipeline 4 are arranged on a first pipeline between the raw material tank 2 and the microchannel reactor 5, the input pump 3 is used for inputting raw materials into the microchannel reactor 5, a chlorine mass flow meter 6 is arranged between the microchannel reactor 5 and the chlorine gas bottle 1, and a pressure sensor and a temperature sensor are arranged between the microchannel reactor 5 and the chlorine mass flow meter 6; meanwhile, a pressure sensor and a temperature sensor are arranged between the micro-channel reactor 5 and the delay pipeline 10, and the tail end of the delay pipeline is provided with the temperature sensor for detecting pressure changes before and after chlorination reaction and monitoring reaction temperature.
A chlorine gas inlet control valve, a gas flowmeter for detecting the gas flow and a gas inlet pressure gauge for detecting the gas pressure condition are arranged between the second pipeline chlorine gas bottle 1 and the microchannel reactor 5; a three-way valve is arranged between the chlorine gas cylinder 1 and the chlorine gas mass flowmeter 6 in the second pipeline, the three-way valve is connected with the outlet of the nitrogen gas cylinder 7 through a third pipeline, and a gas inlet control valve and a gas inlet pressure gauge are arranged on the pipeline; the tail ends of the micro-channel reactor 5 and the delay pipeline 10 are respectively provided with a sampling port; and a back pressure valve 11 is arranged at the tail end of the delay pipeline.
And a gas dryer (for drying chlorine and nitrogen) is arranged between the three-way valve arranged on the second pipeline and the gas mass flowmeter 6.
And the tail ends of the micro-channel reactor and the delay pipeline are respectively provided with a sampling port for sampling and analyzing the reaction state. The delay line may be not only one stage but also two or more stages. And the tail end of the delay pipeline is provided with a back pressure valve for carrying out back pressure on the reaction system, enhancing mass transfer and accelerating the reaction speed.
Example 2
Preparation of raw material liquid: removing dissolved oxygen in raw material trichloroethylene and solvent dichloromethane by using dry nitrogen in a bubbling mode, dissolving the trichloroethylene in the solvent, and adding a polymerization inhibitor (2, 6-di-tert-butyl-p-cresol) to obtain a raw material solution, wherein the raw material solution contains 0.1 wt% of polymerization inhibitor and 20% of trichloroethylene solution by mass concentration.
Then the materials are introduced into the apparatus, firstly, N is used2Purging the experimental device to eliminate water vapor and impurities in the reaction system. And (3) inputting the raw material liquid obtained by the preparation into a raw material tank, and introducing nitrogen into the top space of the raw material tank for protection. Under the ultraviolet irradiation, the gas valve of the chlorine gas cylinder is opened, the chlorine gas passes through the dryer to remove the residual trace moisture in the chlorine gas, the pressure of the chlorine gas outlet is controlled to be 0.2Mpa by the pressure reducing valve, and the volume flow is controlled to be 500ml/min by the mass flow meter. The raw material liquid of trichloroethylene and chlorine gas are mixed according to the ratio of 1:1.1, the reaction temperature is 30 ℃, the materials are efficiently mixed in the microchannel reactor, the residence time of the reaction materials is controlled to be 420s by controlling the length of a delay pipeline, and the complete reaction of the raw materials is ensured. And directly carrying out liquid caustic washing on the reaction liquid flowing out of the time delay pipeline to obtain crude pentachloroethane. The pentachloroethane with the purity of 98.5 percent is obtained by rectification, and the calculated yield is 97.5 percent.
Example 3
Preparation of raw material liquid: removing dissolved oxygen in raw material trichloroethylene and solvent dichloromethane by using dry nitrogen in a bubbling mode, dissolving the trichloroethylene in the solvent, and adding a polymerization inhibitor (2, 6-di-tert-butyl-p-cresol) to obtain a raw material solution, wherein the raw material solution contains 0.1 wt% of polymerization inhibitor and 20% of trichloroethylene solution by mass concentration.
And then introducing the materials into the device, and firstly, purging the experimental device by using N2 to eliminate water vapor and impurities in the reaction system. And (3) inputting the raw material liquid obtained by the preparation into a raw material tank, and introducing nitrogen into the top space of the raw material tank for protection. Under the ultraviolet irradiation, the gas valve of the chlorine gas cylinder is opened, the chlorine gas passes through the chlorine gas dryer to remove the residual trace moisture in the chlorine gas, the pressure of the chlorine gas outlet is controlled to be 0.2Mpa by a pressure reducing valve, and the volume flow is controlled to be 500ml/min by a mass flow meter. The raw material liquid of trichloroethylene and chlorine gas are mixed according to the ratio of 1:1.1, the reaction temperature is 50 ℃, the materials are efficiently mixed in the microchannel reactor, the residence time of the reaction materials is controlled to be 120s by controlling the length of a delay pipeline, and the complete reaction of the raw materials is ensured. And directly carrying out liquid caustic washing on the reaction liquid flowing out of the time delay pipeline to obtain crude pentachloroethane. The pentachloroethane with the purity of 98.2 percent is obtained by rectification, and the calculated yield is 97.7 percent.
Example 4
Preparation of raw material liquid: removing the raw material trichloroethylene and dissolved oxygen in a solvent by using dry nitrogen in a bubbling mode, dissolving the trichloroethylene in the solvent, and adding a polymerization inhibitor (2, 6-di-tert-butyl-p-cresol) to obtain a raw material solution, wherein the raw material solution contains 0.1 wt% of the polymerization inhibitor and 20% of trichloroethylene solution by mass concentration.
Then the materials are introduced into the apparatus, firstly, N is used2Purging the experimental device to eliminate water vapor and impurities in the reaction system. And (3) inputting the raw material liquid obtained by the preparation into a raw material tank, and introducing nitrogen into the top space of the raw material tank for protection. Under the ultraviolet irradiation, the gas valve of the chlorine gas cylinder is opened, the chlorine gas passes through the chlorine gas dryer to remove the residual trace moisture in the chlorine gas, the pressure of the chlorine gas outlet is controlled to be 0.3Mpa by a pressure reducing valve, and the volume flow is controlled to be 500ml/min by a mass flow meter. The raw material liquid of trichloroethylene and chlorine gas are mixed according to the ratio of 1:1.1 molar ratio, reaction temperature 50 ℃ and reaction in a microchannelThe reactor is internally and efficiently mixed, the length of a delay pipeline is controlled to control the retention time of reaction materials to be 240s, and the complete reaction of raw materials is ensured. And directly carrying out liquid caustic washing on the reaction liquid flowing out of the time delay pipeline to obtain crude pentachloroethane. The pentachloroethane with the purity of 99.2 percent is obtained by rectification, and the calculated yield is 98.3 percent.
Example 5
Preparation of raw material liquid: removing dissolved oxygen in raw material trichloroethylene and solvent dichloromethane by using dry nitrogen in a bubbling mode, dissolving the trichloroethylene in the solvent, and adding a polymerization inhibitor (2, 6-di-tert-butyl-p-cresol) to obtain a raw material solution, wherein the raw material solution contains 0.1 wt% of polymerization inhibitor and 20% of trichloroethylene solution by mass concentration.
And then introducing the materials into the device, and firstly, purging the experimental device by using N2 to eliminate water vapor and impurities in the reaction system. And (3) inputting the raw material liquid obtained by the preparation into a raw material tank, and introducing nitrogen into the top space of the raw material tank for protection. Under the ultraviolet irradiation, the gas valve of the chlorine gas cylinder is opened, the chlorine gas passes through the chlorine gas dryer to remove the residual trace moisture in the chlorine gas, the pressure of the chlorine gas outlet is controlled to be 0.2Mpa by a pressure reducing valve, and the volume flow is controlled to be 500ml/min by a mass flow meter. The raw material liquid of trichloroethylene and chlorine gas are mixed according to the ratio of 1:1, the reaction temperature is 50 ℃, the materials are efficiently mixed in the microchannel reactor, the residence time of the reaction materials is controlled to be 240s by controlling the length of a delay pipeline, and the complete reaction of the raw materials is ensured. And directly carrying out liquid caustic washing on the reaction liquid flowing out of the time delay pipeline to obtain crude pentachloroethane. The pentachloroethane with the product purity of 98 percent is obtained by rectification, and the calculated yield is 96.5 percent.
Comparative example 1
Pentachloroethane was synthesized using trichloroethylene as the starting material using a batch process reported in the literature. Under the irradiation of ultraviolet light, the raw materials of trichloroethylene and chlorine are mixed according to the ratio of 1:1.1, mixing, introducing into a quartz glass tubular reactor at 120 ℃ until the raw materials react completely, collecting the generated reaction liquid, and performing alkali washing by using alkali liquor to obtain the crude pentachloroethane. Then the product pentachloroethane with the purity of 98 percent is obtained through the rectification process, and the yield is 88.5 percent.
Comparative example 2
Preparation of raw material liquid: trichloroethylene is dissolved by a solvent (dichloromethane) to obtain a raw material solution, and the raw material solution contains a trichloroethylene solution with the mass concentration of 20%.
Then the materials are introduced into the apparatus, firstly, N is used2Purging the experimental device to eliminate water vapor and impurities in the reaction system. And (3) inputting the raw material liquid obtained by the preparation into a raw material tank, opening an air valve of a chlorine gas cylinder under the ultraviolet illumination, controlling the pressure of a chlorine gas outlet to be 0.3Mpa through a pressure reducing valve, and controlling the volume flow to be 500ml/min through a mass flow meter. The raw material liquid of trichloroethylene and chlorine gas are mixed according to the ratio of 1:1.1, the reaction temperature is 50 ℃, the materials are efficiently mixed in the microchannel reactor, the residence time of the reaction materials is controlled to 240s by controlling the length of a delay pipeline, and the complete reaction of the raw materials is ensured. And directly carrying out liquid caustic washing on the reaction liquid flowing out of the time delay pipeline to obtain crude pentachloroethane. The rectification is carried out to obtain the pentachloroethane with the purity of 97.8 percent, and the calculated yield is 91.3 percent.
The yield of the product is obviously lower than that of the embodiment in the comparative example 1, the comparative example 1 adopts an intermittent type mode, the mass transfer effect is poor, the gas-phase homogeneous reaction is insufficient, the side reaction is obvious, the used raw materials are not subjected to deoxidization and dehydration treatment, nitrogen protection and polymerization inhibitor addition, the chlorination addition reaction is directly carried out, the inevitable side reaction can be generated, under the existence of oxygen, the trichloroethylene and the oxygen are firstly subjected to oxidation reaction to generate trichloroethylene epoxide, and then the dichloroacetyl chloride is generated through rearrangement conversion reaction; and at high temperature (100 ℃ C. and 130 ℃ C.), tetrachloroethyl free radicals are generated, and under the induction of oxygen, polymerization reaction is carried out to generate dimeric tetrachloroethane oxide, so that byproducts such as dichloroacetyl chloride, dimeric tetrachloroethane oxide and tetrachloroethylene are generated while the product is obtained, and the product yield is influenced to a certain extent.
In addition, in comparative example 2, although the efficient mixing in the reaction and the reaction process in the delay line are solved to a great extent by the continuous process, the back mixing is reduced, but due to the particularity of the reaction, the raw material liquid is not pretreated, thereby affecting the reaction efficiency and the purity of the product.
The embodiment of the invention can solve the problems in the prior art, and has more outstanding effect under certain conditions.
Claims (10)
1. A device for continuously synthesizing pentachloroethane by taking trichloroethylene as a raw material is characterized in that: the device comprises a chlorine gas cylinder 1, a raw material tank 2, a metering pump 3, a preheating pipeline 4, a micro-channel reactor 5, a gas mass flow meter 6, a nitrogen gas cylinder 7, a sampling valve 8, a light source 9, a delay pipeline 10, a backpressure valve 11 and a storage tank 12; the micro-reactor 5 is provided with two feeding ports and a discharging port, and the raw material tank 2 is connected with one feeding port of the micro-channel reactor 5 through a first pipeline; the chlorine gas cylinder 1 is connected with the other feeding port of the microchannel reactor 5 through a second pipeline; and the discharge port of the micro-channel reactor 5, the delay pipeline 10, the backpressure valve 11 and the storage tank 12 are sequentially connected in series through pipelines.
2. The apparatus of claim 1, wherein: an input pump 3 and a preheating pipeline 4 are arranged on a first pipeline between the raw material tank 2 and the microchannel reactor 5, the input pump 3 is used for inputting raw materials into the microchannel reactor 5, a chlorine mass flow meter 6 is arranged between the microchannel reactor 5 and the chlorine gas bottle 1, and a pressure sensor and a temperature sensor are arranged between the microchannel reactor 5 and the chlorine mass flow meter 6; meanwhile, a pressure sensor and a temperature sensor are arranged between the micro-channel reactor 5 and the delay pipeline 10, and a temperature sensor is arranged at the tail end of the delay pipeline.
3. The apparatus of claim 1, wherein: a chlorine gas inlet control valve, a gas flowmeter for detecting the gas flow and a gas inlet pressure gauge for detecting the gas pressure condition are arranged between the second pipeline chlorine gas bottle 1 and the microchannel reactor 5; a three-way valve is arranged between the chlorine gas cylinder 1 and the chlorine gas mass flowmeter 6 in the second pipeline, the three-way valve is connected with the outlet of the nitrogen gas cylinder 7 through a third pipeline, and a gas inlet control valve and a gas inlet pressure gauge are arranged on the pipeline; the tail ends of the micro-channel reactor 5 and the delay pipeline 10 are respectively provided with a sampling port; and a back pressure valve 11 is arranged at the tail end of the delay pipeline.
4. The apparatus of any of claims 1-3, wherein: and a gas drier is arranged between the three-way valve arranged on the second pipeline and the gas mass flow meter 6.
5. A method for continuously synthesizing pentachloroethane by using trichloroethylene as a raw material by using the device of claim 1, which is characterized in that: firstly, introducing dried nitrogen into a microchannel reactor 5; then, dehydrating the chlorine gas through a mass flow controller and a dryer and introducing the chlorine gas into a reactor system; then pumping the raw material liquid containing trichloroethylene into a microchannel reactor, leading the raw material liquid and the introduced chlorine gas to be fully and uniformly mixed in the microchannel reactor, continuously carrying out continuous chlorination addition reaction on the mixed gas-liquid mixture in a delay pipeline under the action of illumination, and processing the liquid phase product after the reaction to obtain the high-yield pentachloroethane.
6. The method of claim 5, wherein: the raw material liquid containing trichloroethylene is prepared by dissolving trichloroethylene in a solvent, and adding a polymerization inhibitor with the mass of 0.05-0.5% of the dissolved liquid; trichloroethylene in raw material liquid
The content is 10 wt% -70 wt%; the solvent is one or more of dichloromethane, methanol and diethyl ether.
7. The method of claim 5, wherein: the molar flow ratio of the trichloroethylene to the chlorine in the gas-liquid two phases introduced into the reactor is controlled to be 1:0.9-1: 1.5; the gas inlet pressure of the chlorine is 0.05-0.7 Mpa.
8. The method of claim 5, wherein: the temperature of the raw material liquid in the preheating pipeline is 20-80 ℃, and the temperature in the microchannel reactor and the delay pipeline is 20-90 ℃.
9. The method of claim 5, wherein: the residence time of the reaction liquid in the delay pipeline (10) can be controlled to be 20-480 s.
10. The method of claim 5, wherein: the light source can be one or more of ultraviolet light, xenon (mercury) light source and LED lamp.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111444162.0A CN114452915A (en) | 2021-11-30 | 2021-11-30 | Method and device for continuously synthesizing pentachloroethane by using trichloroethylene as raw material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111444162.0A CN114452915A (en) | 2021-11-30 | 2021-11-30 | Method and device for continuously synthesizing pentachloroethane by using trichloroethylene as raw material |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114452915A true CN114452915A (en) | 2022-05-10 |
Family
ID=81406609
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111444162.0A Pending CN114452915A (en) | 2021-11-30 | 2021-11-30 | Method and device for continuously synthesizing pentachloroethane by using trichloroethylene as raw material |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114452915A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114736097A (en) * | 2022-05-13 | 2022-07-12 | 马鞍山昂扬新材料科技有限公司 | High-efficiency synthesis process of dibromoethane micro-channel |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101265154A (en) * | 2008-03-27 | 2008-09-17 | 常熟三爱富氟化工有限责任公司 | Method for preparing pentafluoroethane |
| CN105384617A (en) * | 2015-12-11 | 2016-03-09 | 大连世慕化学有限公司 | Method using micro reactor to prepare 1-chloro-1'-chloroacetyl cyclopropane |
| CN105418548A (en) * | 2015-12-11 | 2016-03-23 | 大连世慕化学有限公司 | Microreactor used for alpha-position hydrogen atom chlorination of alpha-dicarbonyl compound and synthesis method |
| CN106608811A (en) * | 2015-10-27 | 2017-05-03 | 江西天宇化工有限公司 | Method used for preparing chloropropene using microchannel reactors |
| CN111617711A (en) * | 2020-06-15 | 2020-09-04 | 辽宁石化职业技术学院 | Microreactor and diarylethane preparation method based on microreactor |
-
2021
- 2021-11-30 CN CN202111444162.0A patent/CN114452915A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101265154A (en) * | 2008-03-27 | 2008-09-17 | 常熟三爱富氟化工有限责任公司 | Method for preparing pentafluoroethane |
| CN106608811A (en) * | 2015-10-27 | 2017-05-03 | 江西天宇化工有限公司 | Method used for preparing chloropropene using microchannel reactors |
| CN105384617A (en) * | 2015-12-11 | 2016-03-09 | 大连世慕化学有限公司 | Method using micro reactor to prepare 1-chloro-1'-chloroacetyl cyclopropane |
| CN105418548A (en) * | 2015-12-11 | 2016-03-23 | 大连世慕化学有限公司 | Microreactor used for alpha-position hydrogen atom chlorination of alpha-dicarbonyl compound and synthesis method |
| CN111617711A (en) * | 2020-06-15 | 2020-09-04 | 辽宁石化职业技术学院 | Microreactor and diarylethane preparation method based on microreactor |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114736097A (en) * | 2022-05-13 | 2022-07-12 | 马鞍山昂扬新材料科技有限公司 | High-efficiency synthesis process of dibromoethane micro-channel |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP1448501B1 (en) | Photochlorination of 1,1,1,3,3-pentafluoropropane | |
| JP7092861B2 (en) | Method for producing C3 chlorinated alkane and alkene compound | |
| CN107216233B (en) | Resource utilization method of trifluoromethane | |
| JP2000508315A (en) | Purification of 1,1,1,3,3-pentafluoropropane (R-245fa) | |
| CN114452915A (en) | Method and device for continuously synthesizing pentachloroethane by using trichloroethylene as raw material | |
| TWI755352B (en) | A process for producing highly pure chlorinated alkane | |
| CN107188778A (en) | The preparation method of octafluoro cyclopentene | |
| CN111470939B (en) | Production device and method for continuously producing 2-bromo-3, 3-trifluoropropene | |
| FR2903685A1 (en) | PROCESS FOR OBTAINING 1,2-DICHLOROETHANE BY DIRECT CHLORINATION WITH DIRECT EVAPORATION CATALYST SEPARATION STEP AND INSTALLATION FOR CARRYING OUT SAID METHOD | |
| CN102531827A (en) | Method for preparing dichloroethane through direct chlorination by using dry gas | |
| CN110746265A (en) | Method for continuously producing fluorinated alkane in pipeline manner by liquid phase method | |
| US3933980A (en) | Process for removing ethylenically unsaturated chlorinated hydrocarbons from gas streams | |
| AU645648B2 (en) | Process for removing vinylidene chloride and other unsaturated compounds from 1,1-dichloro-1-fluoroethane | |
| CN110818558A (en) | Method and device for continuously preparing chloro pivaloyl chloride by using micro-channel | |
| CN105503515B (en) | A kind of continuous preparation method of short chain perfluoroalkyl iodide | |
| JP2001311686A (en) | Method and apparatus for measurement of concentration of fluorine compound as well as manufacturing method for fluorine compound | |
| TW202116712A (en) | Alkane production method | |
| JP6989519B2 (en) | process | |
| CN110790632A (en) | Method for producing fluorinated alkane through liquid phase method pipelining continuous separation | |
| CN104058928A (en) | Method for increasing production capacity of device in bromine-containing hydrofluoroalkane synthesis | |
| US3629085A (en) | Photochemical purification of 1,2-dichlorethane | |
| CN211311346U (en) | Device for continuously preparing chloro-pivaloyl chloride by using micro-channel | |
| CN117510454B (en) | Preparation method of chloroethylene carbonate | |
| CN113402359B (en) | Method for preparing 2, 6-dichlorotoluene by chlorination of chlorine-containing organic solvent in subcritical state | |
| CN113754513A (en) | Method and device for removing small amount of fluorine-containing olefin in octafluorocyclobutane |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |