Reaction device for co-producing trichloroethylene and tetrachloroethylene by dichloroethane oxychlorination method

Abstract

The utility model discloses a reaction device for co-producing trichloroethylene and tetrachloroethylene by using a dichloroethane oxychlorination method, and relates to a trichloroethylene and tetrachloroethylene preparation device, which comprises a dichloroethane storage tank, an HCL storage bottle, an oxygen storage bottle, a tubular reactor, a heating device, a primary preheater, a gas mixer and a fused salt heat conduction sleeve, the primary preheater is connected with the gas mixer, the HCL storage bottle and the oxygen storage bottle are respectively connected with the mixing pipe section, the mixing pipe section is respectively connected with an inlet of the gas mixer and the middle part of the tubular reactor, and the gas mixer is connected with the upper end of the tubular reactor; the fused salt heat conduction sleeve is sleeved outside the tubular reactor, heat conduction fused salt is arranged in the fused salt heat conduction sleeve, and the heating device is arranged outside the fused salt heat conduction sleeve. The method has the advantages that heat release is dispersed, local reaction pressure is small, and the yield ratio of trichloroethylene to tetrachloroethylene can be rapidly adjusted according to needs.

Description

TECHNICAL FIELD

[0001] The utility model relates to trichloroethylene and tetrachloroethylene preparation device, especially to a kind of reaction device of oxychlorination of dichloroethane coproduction trichloroethylene and tetrachloroethylene BACKGROUND

[0002] We know that trichloroethylene, tetrachloroethylene are common organic compounds, colorless transparent liquid at room temperature.Trichloroethylene is mainly used as solvent, can be used for cleaning agent, metal degreasing agent, refrigerant, pesticide, spice, rubber industry and washing fabric, etc., it was also used as analgesic and extractant‌12.Tetrachloroethylene is commonly used as dry cleaning agent, organic solvent, drying agent, paint remover, insect repellent and fatty extractant etc.Both trichloroethylene and tetrachloroethylene can be produced by dichloroethane oxychlorination method, the existing reaction device for producing trichloroethylene and tetrachloroethylene using dichloroethane oxychlorination method, including tubular reactor and heating device, heating device is arranged outside the tubular reactor, the tubular reactor is equipped with packing and catalyst, the upper portion of tubular reactor is equipped with chlorine-oxygen mixed gas feeding port, the middle part of tubular reactor is equipped with dichloroethane feeding pipe, such as the application publication number: CN108129257A, the name is: reactor and method for preparing tetrachloroethylene with dichloroethane as raw material, published the reaction device structure of output trichloroethylene and tetrachloroethylene similar to the above structure.

[0003] The existing reaction device for producing trichloroethylene and tetrachloroethylene has the defects of concentrated heat release and large local reaction pressure, and the yield ratio of trichloroethylene and tetrachloroethylene cannot be adjusted, and the yield ratio of trichloroethylene and tetrachloroethylene cannot be changed according to needs. UTILITY MODEL CONTENT

[0004] The utility model aims at solving the above-mentioned prior art, and provides a reaction device for coproducing trichloroethylene and tetrachloroethylene by dichloroethane oxychlorination method, which has the advantages of dispersed heat release, small local reaction pressure and quick adjustment of the yield ratio of trichloroethylene and tetrachloroethylene according to needs.

[0005] The utility model solves the above-mentioned prior art by adopting the following technical solutions:

[0006] The utility model provides a kind of reaction device for the oxychlorination of dichloroethane to co-produce trichloroethylene and tetrachloroethylene, including dichloroethane storage tank, HCL storage bottle, oxygen storage bottle, tubular reactor and heating device, characterized by further including first preheater, gas mixer and molten salt heat jacket, the outlet of the dichloroethane storage tank is connected with the inlet of first preheater by metering pump, the outlet of first preheater is connected with the inlet of gas mixer, HCL storage bottle outlet and oxygen storage bottle outlet are connected with mixed pipe section by HCL flow control valve and oxygen flow control valve respectively, mixed pipe section is connected with gas mixer inlet and tubular reactor middle part by first shunt valve and second shunt valve respectively, and gas mixer outlet is connected with the upper end of tubular reactor;The molten salt heat jacket is sleeved outside tubular reactor, and heat-conducting molten salt is arranged in molten salt heat jacket, and the heating device is installed outside molten salt heat jacket.

[0007] Further, the gas mixer outlet is connected with second preheater, and the outlet of second preheater is connected with the upper end of tubular reactor. The uniformly mixed reactants can be preheated to reaction temperature, and the reaction can occur after contacting catalyst in the reactor, so that the temperature influence on reaction progress is avoided.

[0008] Further, the lower end of the tubular reactor is connected with condenser, and the outlet of the condenser is connected with gas-liquid separation tank.

[0009] Further, the heating device includes upper segment heating device, middle segment heating device and lower segment heating device, which are installed outside molten salt heat jacket from top to bottom. The upper segment heating device, middle segment heating device and lower segment heating device can control temperature respectively, and the reaction temperature control precision in the tubular reactor is higher, and the conversion rate is improved.

[0010] Preferably, the mixed pipe section is connected with gas feeding pipe through the second shunt valve, and the gas feeding pipe enters from the upper end of the tubular reactor and extends to the middle part in the tubular reactor.

[0011] Preferably, the lower end of the gas feeding pipe is provided with a porous nozzle.

[0012] In operation, the dichloroethane in the dichloroethane storage tank is metered and pumped to the primary preheater for preheating, which turns the dichloroethane into a gaseous state. HCl and oxygen from the HCl and oxygen storage bottles are metered into the mixing section via HCl and oxygen flow control valves, respectively. A portion of the mixture is then mixed with the gaseous dichloroethane via the first diversion valve and enters the gas mixer, while the other portion is transported to the middle section of the tubular reactor via the second diversion valve. After thorough mixing in the gas mixer, the mixture enters the secondary preheater for secondary preheating before the reaction. It then enters the tubular reactor from the top and undergoes a preliminary oxychlorination reaction in the upper part of the reactor. After the preliminary oxychlorination reaction, the mixture flows below the middle section of the tubular reactor and undergoes a second oxychlorination reaction with the oxygen and chlorine gas supplied to the middle section via the second diversion valve. The product is then discharged from the outlet at the bottom of the tubular reactor for further processing. Because the reactants undergo two oxychlorination reactions at different positions above and below the tubular reactor, the phenomenon of concentrated heat release is reduced. Using molten salt as the heat-conducting material between the heating device and the tubular reactor results in more uniform heating. When the reaction is exothermic and the temperature inside the tubular reactor rises, the molten salt with high volume heat fusion can absorb heat and conduct it outward, making the reaction temperature easier to control. By controlling the flow rates of the first and second diversion valves, the proportion of trichloroethylene and tetrachloroethylene in the product can be adjusted. During production, adjustments can be made according to the target product, making it convenient to use and applicable to a wide range of applications. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of this utility model. Detailed Implementation

[0014] like Figure 1The shown reaction device for co-production of trichloroethylene and tetrachloroethylene by dichloroethane oxychlorination method comprises a dichloroethane storage tank 3, an HCL storage bottle 2, an oxygen storage bottle 1, a tubular reactor 12 and a heating device 9, further comprising a first preheater 5, a gas mixer 16, a second preheater 15 and a molten salt heat conducting jacket 11, the outlet of the dichloroethane storage tank 3 is connected with the inlet of the first preheater 5 through a metering pump and a control valve, the outlet of the first preheater 5 is connected with the inlet of the gas mixer 16, and the gas mixer 16 is an SX static mixer. The outlets of the HCL storage bottle 2 and the oxygen storage bottle 1 are respectively connected with one end of a mixing pipe section 18 through an HCL flow control valve 20 and an oxygen flow control valve 19, the other end of the mixing pipe section 18 is respectively connected with the inlet of the gas mixer 16 and the middle part of the tubular reactor 12 through a first shunt valve 17 and a second shunt valve 14, as shown in the figure, the outlet of the mixing pipe section 18 is connected with a gas feeding pipe 13 through the second shunt valve 14, the gas feeding pipe 13 enters from the upper end of the tubular reactor 12 and extends to the middle part of the tubular reactor 12, and the lower end of the gas feeding pipe 13 is provided with a porous nozzle 10 which is a corrosion-resistant ceramic nozzle and can make the gas disperse quickly to improve the reaction efficiency. The outlet of the gas mixer 16 is connected with the reactant inlet of the upper end of the tubular reactor 12, the molten salt heat conducting jacket 11 is sleeve-shaped and is sleeved outside the tubular reactor 12, the upper and lower ends of the molten salt heat conducting jacket 11 are respectively provided with a circular ring-shaped bottom cover and an upper cover which are fixedly connected with the outside of the tubular reactor, the molten salt heat conducting jacket 11 is provided with a heat conducting molten salt 8, and the heating device 9 is sleeved and installed outside the molten salt heat conducting jacket 11. The tubular reactor is provided with fillers and catalysts, preferably inert fillers loaded with catalysts. The product outlet of the lower end of the tubular reactor is connected with a condenser 7, and the outlet of the condenser 7 is connected with a gas-liquid separation tank 6.

[0015] The heating device 9 comprises an upper heating device, a middle heating device and a lower heating device, which are sequentially arranged outside the molten salt heat conducting sleeve from top to bottom. The upper heating device, the middle heating device and the lower heating device can be respectively connected to the temperature control device and respectively controlled in temperature, so that the reaction temperature in the tubular reactor is controlled in a higher precision and the conversion rate is improved. The outlet of the gas mixer 16 is connected with the inlet of the secondary preheater 15, and the outlet of the secondary preheater 15 is connected with the reactant inlet at the upper end of the tubular reactor 12. The uniformly mixed reactants can be preheated to the required reaction temperature, and the reactants can be reacted after entering the reactor and contacting the catalyst, so that the temperature influence on the reaction progress is avoided. During the working of the utility model, the dichloroethane in the dichloroethane storage tank is quantitatively output to the primary preheater through the metering pump and is preheated, so that the dichloroethane is changed into a gaseous state. The HCL and oxygen in the HCL storage bottle and the oxygen storage bottle are respectively quantitatively flowed into the mixing pipe section through the HCL flow control valve and the oxygen flow control valve after being mixed, and a part of the HCL and oxygen is mixed with the gaseous dichloroethane through the first shunt valve and is input into the gas mixer, and the other part of the HCL and oxygen is transported to the middle position in the tubular reactor through the second shunt valve. After being sufficiently mixed through the gas mixer, the HCL and oxygen are input into the secondary preheater for secondary preheating before reaction, and then are input into the tubular reactor from the upper end of the tubular reactor and are subjected to preliminary oxychlorination reaction in the upper part of the tubular reactor. When the preliminary oxychlorination reaction is completed and the HCL and oxygen flow through the position below the middle position of the tubular reactor, the HCL and oxygen are subjected to secondary oxychlorination reaction with the oxygen and the chlorine gas which are input into the middle position of the tubular reactor through the second shunt valve. Then the product is discharged from the outlet at the lower end of the tubular reactor to the condenser 7 for cooling and is subjected to gas-liquid separation through the gas-liquid separation tank 6. The obtained trichloroethylene and tetrachloroethylene are separated through multi-tower rectification.

[0016] The utility model discloses because the reactants are subjected to two oxychlorination reactions at different positions of the tubular reactor, the concentrated heat release phenomenon is reduced. The molten salt is used as the heat conducting material between the heating device and the tubular reactor, so that the heating is more uniform. When the reaction releases heat and the temperature in the tubular reactor rises, the molten salt with high volume heat melting can absorb the heat and conduct the heat outward, so that the reaction temperature is more easily controlled. By controlling the flow of the first shunt valve and the second shunt valve, the proportion of trichloroethylene and tetrachloroethylene in the product can be adjusted. The target product can be adjusted during production, so that the utility model is convenient to use and has a wide range of applications.

Claims

1. A reaction device for the oxychlorination of dichloroethane to co-produce trichloroethylene and tetrachloroethylene, comprising a dichloroethane storage tank, an HCL storage bottle, an oxygen storage bottle, a tubular reactor and a heating device, characterized in that, The first-stage preheater, the gas mixer and the molten salt heat jacket are further included, the outlet of the ethylene dichloride storage tank is connected with the inlet of the first-stage preheater through a metering pump, the outlet of the first-stage preheater is connected with the inlet of the gas mixer, the outlet of the HCL storage bottle and the outlet of the oxygen storage bottle are respectively connected with the mixing pipe section through an HCL flow control valve and an oxygen flow control valve, the mixing pipe section is respectively connected with the inlet of the gas mixer and the middle part of the tubular reactor through a first shunt valve and a second shunt valve, the outlet of the gas mixer is connected with the upper end of the tubular reactor, the molten salt heat jacket is sleeved outside the tubular reactor, and the molten salt heat jacket is provided with heat-conducting molten salt, and the heating device is installed outside the molten salt heat jacket.

2. The reaction apparatus for co-producing trichloroethylene and tetrachloroethylene by dichloroethane oxychlorination process according to claim 1, characterized by, The gas mixer is connected with a second-stage preheater, and the outlet of the second-stage preheater is connected with the upper end of the tubular reactor.

3. The reaction apparatus for co-producing trichloroethylene and tetrachloroethylene in the oxychlorination process of dichloroethane according to claim 1 or 2, characterized in that, The lower end of the tubular reactor is connected with a condenser, and the outlet of the condenser is connected with a gas-liquid separation tank.

4. The reaction apparatus for co-producing trichloroethylene and tetrachloroethylene in the dichloroethane oxychlorination process according to claim 1 or 2, characterized by The heating device comprises an upper-section heating device, a middle-section heating device and a lower-section heating device, and the upper-section heating device, the middle-section heating device and the lower-section heating device are installed outside the molten salt heat jacket from top to bottom.

5. The reaction apparatus for co-producing trichloroethylene and tetrachloroethylene by dichloroethane oxychlorination process according to claim 4, characterized by, The mixing pipe section is connected with a gas feeding pipe through the second shunt valve, the gas feeding pipe enters from the upper end of the tubular reactor and extends to the middle part of the tubular reactor.

6. The reaction apparatus for co-producing trichloroethylene and tetrachloroethylene by dichloroethane oxychlorination process according to claim 5, characterized by, The lower end of the gas feeding pipe is provided with a porous nozzle.

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