Reaction device for chloroethylene carbonate

Abstract

The utility model belongs to the technical field of chloroethylene carbonate reaction, and particularly discloses a chloroethylene carbonate reaction device which comprises a reaction kettle, the top end of the reaction kettle is connected with an EC feed pipe, a tail gas pipe and a chlorine pipe, the inlet end of the chlorine pipe is connected with a buffer tank, and the bottom end of the chlorine pipe is provided with a CEC discharge pipe; a reaction lamp is arranged in the reaction kettle; a sampling pipe is arranged outside the reaction kettle, a reaction progress controller is connected to the sampling pipe, the reaction progress controller comprises a cooler connected with the reaction kettle, an outlet pipe of the cooler is connected to a CEC discharge pipe, and a tuning fork densimeter, a temperature sensor and a pressure transmitter are arranged on the outlet pipe of the cooler; according to the utility model, the reaction progress of CEC in the reaction kettle is monitored in real time by arranging the reaction progress device, so that the reaction progress of CEC can be monitored in real time, time and labor are saved, and the reaction progress can be monitored in real time instead of gas chromatographic analysis.

Description

Technical Field

[0001] The utility model belongs to the technical field of chloroethylene carbonate reaction, and particularly relates to a reaction device for chloroethylene carbonate. Background Art

[0002] When preparing chloroethylene carbonate (CEC) by reacting ethylene carbonate (EC) with chlorine (CL 2 )), the reaction will generate CEC, DCEC and hydrogen chloride gas, and the reaction solution is strongly acidic. The reaction process is usually carried out in an enamel reaction kettle; this reaction belongs to batch operation. During the CEC reaction process, it is necessary to continuously perform gas chromatography analysis on the reaction solution to monitor the reaction progress. However, each gas chromatography analysis has to go through the processes of sampling, sample delivery, analysis, report generation and then feedback to the control center, which is not only time-consuming and laborious, but also unable to achieve real-time monitoring of the CEC reaction progress.

[0003] The Chinese patent document with the application publication number CN106861580A discloses an enamel reaction device capable of precisely controlling the reaction progress, including a reaction vessel cover, a reaction vessel body, and a ventilation pipe provided with a ventilation inlet and an air outlet. The reaction vessel cover is provided with a pipeline connection device connected to the ventilation pipe. The air outlet extends into the reaction vessel body through the pipeline connection device. The air outlet is arranged at the lower end of the ventilation pipe, and the ventilation pipe is movably connected to the pipeline connection device, and the ventilation pipe makes a vertical movement relative to the pipeline connection device; it also includes a pressure device, a pressure rod and a pressure table. The pressure device is sequentially connected to the ventilation pipe through the pressure rod and the pressure table, and the pressure device is used to control the vertical movement of the ventilation pipe. The ventilation inlet is arranged on one side of the pressure table outside the reaction vessel cover; it also includes a thermometer sleeve. The reaction vessel cover is provided with a thermometer sleeve fixing device, and the thermometer sleeve extends into the reaction vessel body through the thermometer sleeve fixing device. This application only controls the reaction process by measuring the temperature inside the reaction vessel body, but the reaction temperature cannot accurately represent the reaction process. Therefore, the reaction process cannot be accurately monitored by measuring the temperature, and the purpose of real-time monitoring of the reaction process cannot be achieved. Content of the Utility Model

[0004] In order to solve the above problems, this patent provides a reaction device for chloroethylene carbonate that can monitor the reaction progress in real time.

[0005] Based on the above purposes, the utility model is realized through the following technical solutions:

[0006] A reaction device for vinyl chloroformate, comprising a reaction kettle, wherein the top of the reaction kettle is connected with an EC feed pipe, a tail gas pipe and a chlorine gas pipe, and the bottom is provided with a CEC discharge pipe; the inlet end of the chlorine gas pipe is connected with a buffer tank; a reaction lamp is arranged in the reaction kettle; a sampling pipe is arranged outside the reaction kettle, and a reaction progress controller is connected to the sampling pipe. The reaction progress controller includes a cooler connected to the reaction kettle, and the outlet pipe of the cooler is connected to the CEC discharge pipe. A tuning fork densitometer, a temperature sensor and a pressure transmitter are arranged on the outlet pipe of the cooler.

[0007] Preferably, the tuning fork densitometer is connected with a density calculator with a display and operation unit. The density calculator is connected to the temperature sensor and the pressure transmitter, and the density calculator is connected with a PLC; the tuning fork densitometer is a tuning fork densitometer with pulse output. The density calculator collects the density data measured by the tuning fork densitometer, processes the density data through a built-in density calculation program, and displays the processed density data; the density calculator is a computer with a density calculation program, which can process the data collected by the tuning fork densitometer.

[0008] Preferably, the chlorine gas pipe extends to the bottom of the reaction kettle.

[0009] Preferably, the reaction lamp is an ultraviolet lamp, and the reaction lamp uses an ultraviolet UV lamp tube.

[0010] Preferably, there are at least 2 groups of ultraviolet lamps.

[0011] Preferably, the sampling pipe is arranged in the upper middle part of the reaction kettle. The outlet of the sampling pipe is connected to the top of the cooler, and the bottom of the cooler is connected to the tuning fork densitometer.

[0012] Preferably, the circulating water inlet pipe of the cooler is arranged at the lower part of the cooler, and the circulating water return pipe is arranged at the upper part of the cooler.

[0013] Preferably, a tail gas valve is arranged on the tail gas pipe; an outlet valve is arranged on the outlet pipe, and a control valve with clearance fit with the outlet pipe is arranged at one end of the CEC discharge pipe close to the reaction kettle.

[0014] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0015] The present utility model can monitor the reaction process of CEC in the reaction kettle in real time by setting a reaction progress controller, and can monitor the reaction progress of CEC in real time, which not only saves time and effort, but also can replace gas chromatography analysis to monitor the reaction progress in real time; the reaction progress controller collects the data of the liquid in the outlet pipe in real time online through a tuning fork densitometer, a temperature sensor and a pressure transmitter, and calculates and processes the liquid data collected in real time through a density calculator, and can obtain the real-time concentration of the liquid in the reaction kettle, so as to realize the real-time monitoring of the reaction process of CEC and improve the monitoring efficiency of the reaction process of CEC. Description of the Drawings

[0016] Figure 1 is the structural schematic diagram of the present utility model in Embodiment 1;

[0017] Figure 2 is the schematic diagram of the reaction progress meter in Embodiment 1.

[0018] In the figure, there are tuning fork densitometer 1, temperature sensor 2, pressure transmitter 3, density calculator 4, PLC 5, CEC discharge pipe 6, reaction kettle 7, tail gas pipe 8, chlorine gas pipe 9, EC feed pipe 10, circulating water return pipe 11, cooler 12, circulating water inlet pipe 13, outlet pipe 14, and sampling pipe 15. Detailed implementation manners

[0019] The present utility model will be further described below through specific embodiments, but the scope of the present utility model is not limited.

[0020] Embodiment 1

[0021] A reaction device for vinyl chloroformate, the structure of which is as Figure 1-2 shown, including reaction kettle 7, the top of reaction kettle 7 is connected with EC feed pipe 10, tail gas pipe 8 and chlorine gas pipe 9, the inlet end of chlorine gas pipe 9 is connected with a buffer tank, and the bottom end is provided with CEC discharge pipe 6; a reaction lamp is arranged inside reaction kettle 7; a sampling pipe 15 is arranged outside reaction kettle 7, and a reaction progress controller is connected to sampling pipe 15. The reaction progress meter includes a cooler 12 connected to reaction kettle 7, the outlet pipe 14 of cooler 12 is connected to CEC discharge pipe 6, and a tuning fork densitometer 1, temperature sensor 2 and pressure transmitter 3 are arranged on the outlet pipe 14 of cooler 12. Chlorine gas pipe 9 extends deep into the bottom of reaction kettle 7.

[0022] The tuning fork densitometer 1 is connected with a density calculator 4 with a display and operation unit, the density calculator 4 is connected with temperature sensor 2 and pressure transmitter 3, the density calculator 4 is connected with PLC 5; the tuning fork densitometer 1 is a tuning fork densitometer 1 with pulse output.

[0023] The reaction lamp is an ultraviolet lamp, and the reaction lamp adopts an ultraviolet UV lamp tube. There are at least 2 groups of ultraviolet lamps. Sampling pipe 15 is arranged in the upper middle part of reaction kettle 7, the outlet of sampling pipe 15 is connected to the top of cooler 12, and the bottom of cooler 12 is connected to tuning fork densitometer 1. The circulating water inlet pipe 13 of cooler 12 is arranged at the lower part of cooler 12, and the circulating water return pipe 11 is arranged at the upper part of cooler 12.

[0024] When the reaction device for vinyl chloroformate is in use, since the reaction belongs to batch operation, during the reaction process, EC is first injected into reaction kettle 7 through EC feed pipe 10, and then CL is introduced through chlorine gas pipe 9 2, the reaction takes place under the action of ultraviolet light of the reaction lamp in the upper part of the reactor 7; the whole reaction is divided into four stages. The initial stage of the reaction belongs to the initiation stage, and the intake of CL 2 is 20 - 30 NM 3 / h; after the reaction is initiated, the gas volume of CL 2 gradually increases to 80 - 100 NM 3 / h; when the content of CEC reaches more than 70%, start to reduce the flow rate of CL 2 to 30 - 50 NM 3 / h. When CEC reaches 75%, the flow rate of CL 2 drops to 10 - 20 NM 3 / h.

[0025] Due to the corrosiveness of the CEC reaction system, the cooler 12 of this application uses a shell-and-tube heat exchanger made of graphite or silicon carbide. The material is in the tube side and the circulating water is in the shell side. The liquid phase substance in the CEC reactor 7 enters the tube side of the cooler 12 from the upper head of the cooler 12 along the sampling tube 15. Since chlorine bubbles in ethylene carbonate to form a gas-liquid mixture, the density of the gas-liquid mixture in the reactor 7 decreases; the liquid phase is cooled and enters the CEC discharge pipe 6 along the outlet pipe 14 at the bottom of the cooler 12 for circulating cooling and heat removal; the circulating volume of the liquid changes with the change of the chlorine ventilation volume; when the chlorine ventilation volume is 10 - 100 NM3 / h, the corresponding circulating volume of the liquid is about 2 - 8 T / h; the circulating water flows into the shell side along the circulating water inlet pipe 13 at the bottom of the cooler 12 and flows out of the shell side through the circulating water return pipe 11 at the top of the cooler 12 to realize the cooling of the material in the tube side of the cooler 12; the tail gas generated during the CEC reaction is controlled and discharged through the tail gas pipe 8 in cooperation with the control valve, and the discharged tail gas enters the tail gas processor for harmless treatment.

[0026] This CEC reaction device uses light with a wavelength in the range of 200 - 1000 nm, which is between the ultraviolet and visible light regions. That is, both ultraviolet UV lamps and fluorescent lamps can be used as the light source for the photochemical reaction. Different light sources have a significant impact on the reaction rate and product selectivity; preferably, a UV lamp with a power of about 1 KW and a wavelength between 350 - 450 nm is used as the light source. At this time, the optimal reaction time for the reaction is 8 hours and the CEC selectivity is 85%.

[0027] When the tuning fork densitometer 1 is completely covered by the liquid, the vibration frequency decreases. Based on other information from the temperature sensor 2 and the pressure transmitter 3, and then through the density calculator 4, the corresponding medium density is calculated. When the value of the density change is known, the concentration of the medium can be determined through the calculation formula stored in the system; using empirical data or based on existing tables, the PLC 5 is connected to the density calculator 4, the tuning fork densitometer 1, the temperature sensor 2, and the pressure transmitter 3, facilitating the use of the PLC 5 in this reaction device to achieve automated monitoring of the CEC reaction. The user provides a density-concentration conversion relationship table.

[0028] Generally, the temperature of this CEC reaction device is controlled at 60 °C. As the CEC reaction progresses, through chromatographic analysis of the chemical composition of the reaction solution and combined with the density change situation, after mathematical processing, a "reaction time - liquid density - reaction progress" mapping table of this CEC reaction device is obtained, as shown in the following table. Thus, the relationship between the reaction progress can be deduced by inversely calculating the density of the reaction liquid through the tuning fork test.

[0029] "Reaction time - liquid density - reaction progress" mapping table of this CEC reaction device;

[0030]

[0031]

[0032]

[0033] The above are only the preferred embodiments of the present invention, but not limited to the above examples. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A reaction device for ethylene chlorocarbonate, comprising a reaction kettle, characterized in that: The top of the reactor is connected with an EC feed pipe, an exhaust pipe and a chlorine pipe, and the bottom is provided with a CEC discharge pipe; a reaction lamp is provided inside the reactor; a sampling tube is provided outside the reactor, and a reaction progress controller is connected to the sampling tube. The reaction progress controller includes a cooler connected to the reactor, and the outlet pipe of the cooler is connected to the CEC discharge pipe. A tuning fork density meter, a temperature sensor and a pressure transmitter are provided on the outlet pipe of the cooler.

2. The reaction device of ethylene chlorocarbonate according to claim 1, characterized in that The tuning fork density meter is connected with a density calculator, and the density calculator is connected with a temperature sensor and a pressure transmitter.

3. The reaction device of ethylene chlorocarbonate according to claim 1, characterized in that The chlorine gas pipe goes deep into the bottom of the reactor.

4. The reaction device of ethylene chlorocarbonate according to claim 1, characterized in that The reaction lamp is an ultraviolet lamp.

5. The reaction device of ethylene chlorocarbonate according to claim 4, characterized in that: The ultraviolet lamps have at least 2 groups.

6. The reaction device of ethylene chlorocarbonate according to claim 1, characterized in that: The sampling tube is arranged at the upper middle part of the reaction kettle, the outlet of the sampling tube is connected to the top of the cooler, and the bottom of the cooler is connected to the tuning fork density meter.

7. The reaction device of ethylene chlorocarbonate according to claim 1, characterized in that: The circulating water inlet pipe of the cooler is arranged at the lower part of the cooler, and the circulating water return pipe is arranged at the upper part of the cooler.

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