High-temperature chlorination reactor for preparing dichloroethane from ethylene chlorine

Abstract

The utility model relates to the technical field of preparation of dichloroethane through chlorination, in particular to a high-temperature chlorination reactor for ethylene chlorine. Comprising a circulating part, a separating part and a washing part which are sequentially connected, the circulating part is a U-shaped bent pipe, the separating part is a horizontal tank, the washing part is a spraying pipe, two outlets are formed in the two U-shaped ends of the top of the U-shaped bent pipe and communicated with the bottom of the horizontal tank, and the lower end of the spraying pipe is communicated with the top of the horizontal tank; the high-temperature chlorination reactor disclosed by the utility model is influenced by chlorine dissolution, the chlorine dissolution effect can be obviously improved by increasing the circulation volume, the axial flow pump is arranged to control the static mixer arranged above the distribution pipe to ensure that chlorine is fully dissolved, the reaction conversion rate and the product yield are effectively improved, entrainment and a catalyst entrained in gas can be effectively removed by the washing part, and the product quality is improved. The liquid and the catalyst are recovered to prevent the liquid and the catalyst from being taken out from the top of the reactor.

Description

Technical Field

[0001] This utility model relates to the field of chlorination for the preparation of dichloroethane, specifically a high-temperature chlorination reactor for the preparation of dichloroethane from ethylene chlorine gas. Background Technology

[0002] Coal-to-ethylene technology is becoming increasingly mature, and the annual output of coal-to-ethylene is increasing year by year. Currently, the price advantage of dichloroethane produced by the ethylene method is obvious, and the development prospects of using ethylene and chlorine to produce dichloroethane and then cracking it to produce vinyl chloride are very broad.

[0003] The direct chlorination of ethylene and chlorine to produce dichloroethane is a mature process. It involves the chlorination of ethylene with chlorine under certain temperature and pressure in the liquid phase of dichloroethane to produce 1,2-dichloroethane.

[0004] Currently, direct chlorination processes for ethylene and chlorine mainly employ low-temperature chlorination, medium-temperature chlorination, and high-temperature chlorination. Among these, high-temperature chlorination offers significant advantages in energy utilization and is the primary process used both domestically and internationally. The high-temperature chlorination reactor is the core equipment in the high-temperature chlorination process. Currently used high-temperature chlorination reactors are mainly self-circulating reactors that utilize the pressure difference of the liquid itself to achieve self-circulation. Chlorination reactors that use axial flow pumps to improve circulation have not yet achieved industrial application.

[0005] The self-circulating chlorination reactor for ethylene and chlorine has the following disadvantages: 1. The self-circulation rate is greatly affected by the feed rate. When the feed rate is low, the circulation driving force is insufficient, resulting in a small circulation rate and incomplete dissolution of chlorine and ethylene, affecting the reaction conversion rate and yield. 2. Poor dissolution of chlorine and ethylene leads to an increase in side reactions and a decrease in the yield of dichloroethane. 3. The dichloroethane gas phase outlet carries droplets and small catalyst particles, causing instability in downstream unit operation and catalyst loss. Summary of the Invention

[0006] In view of the above situation and to overcome the defects of the prior art, this utility model provides a high-temperature chlorination reactor for the preparation of dichloroethane from ethylene chlorine gas, which has an adjustable circulation rate, stable reaction control, good reaction effect, high reaction rate, high conversion rate and selectivity, good operational stability and strong anti-interference ability.

[0007] To achieve the above objectives, this utility model provides the following technical solution: a high-temperature chlorination reactor for preparing dichloroethane from ethylene chlorine gas, comprising a circulation section, a separation section, and a washing section connected in sequence, wherein the circulation section is a U-shaped bend, the separation section is a horizontal tank, the washing section is a spray pipe, the two U-shaped ends at the top of the U-shaped bend are provided with two outlets, and the two outlets are connected to the bottom of the horizontal tank, and the lower end of the spray pipe is connected to the top of the horizontal tank;

[0008] The U-shaped bend consists of an outlet pipe and an inlet pipe. The lower part of the outlet pipe is provided with an ethylene inlet and a chlorine inlet. The interior of the outlet pipe is provided with an ethylene distribution pipe and a chlorine distribution pipe, which are respectively connected to the ethylene inlet and the chlorine inlet. The upper part of the ethylene distribution pipe and the chlorine distribution pipe is provided with a mixer. An axial flow pump is provided at the bend where the outlet pipe and the inlet pipe connect.

[0009] Furthermore, a vortex breaker is provided at the connection between the horizontal tank and the inflow pipe.

[0010] Furthermore, the spray pipe is provided with a packing section, and a demister is provided at the top of the packing section. The top of the spray pipe is provided with a crude dichloroethane liquid inlet and a dichloroethane gas phase outlet.

[0011] Furthermore, the ethylene distribution pipe is a single layer with 5 distribution pipes per layer, and small holes are opened on the distribution pipes.

[0012] Furthermore, the chlorine distribution pipe has 2-4 layers, with 5 distribution pipes in each layer, and small holes are opened on the distribution pipes.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] This invention relates to a high-temperature chlorination reactor where chlorine dissolution is a concern. Increasing the circulation rate significantly improves chlorine dissolution. An axial flow pump controls a static mixer located above the distribution pipe to ensure complete chlorine dissolution, effectively increasing reaction conversion and product yield. A washing section effectively removes mist and catalyst entrained in the gas, recovering the liquid and catalyst and preventing them from being carried out from the top of the reactor. This invention effectively improves ethylene conversion, and the equipment is simple, operates stably, and is easy to control. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the internal structure of a front view of an embodiment of the present utility model;

[0016] In the picture:

[0017] Circulation section 1, separation section 2, washing section 3, outflow pipe 11, inflow pipe 12, ethylene inlet 13, chlorine inlet 14, ethylene distribution pipe 15, chlorine distribution pipe 16, mixer 17, axial flow pump 18, vortex breaker 21, packing section 31, demister 32, crude dichloroethane liquid inlet 33, dichloroethane gas phase outlet 34. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0019] Example 1:

[0020] Depend on Figure 1 As shown, a high-temperature chlorination reactor for preparing dichloroethane from ethylene chlorine gas includes a circulation section 1, a separation section 2, and a washing section 3 connected in sequence. The circulation section 1 is a U-shaped bend, the separation section 2 is a horizontal tank, and the washing section 3 is a spray pipe. The two U-shaped ends at the top of the U-shaped bend are provided with two outlets, and the two outlets are connected to the bottom of the horizontal tank. The lower end of the spray pipe is connected to the top of the horizontal tank.

[0021] The U-shaped bend consists of an outflow pipe 11 and an inflow pipe 12. The lower part of the outflow pipe 11 has an ethylene inlet 13 and a chlorine inlet 14. Inside the outflow pipe 11 are ethylene distribution pipes 15 and chlorine distribution pipes 16, which are connected to the ethylene inlet 13 and chlorine inlet 14, respectively. The ethylene distribution pipe 15 is a single layer with 5 distribution pipes per layer, and each distribution pipe has small holes. The chlorine distribution pipes 16 consist of 2-4 layers with 5 distribution pipes per layer, and each distribution pipe has small holes. A mixer 17 is located at the upper part of the ethylene distribution pipes 15 and chlorine distribution pipes 16, and an axial flow pump 18 is located at the bend where the outflow pipe 11 and inflow pipe 12 connect.

[0022] A vortex breaker 21 is provided at the connection between the horizontal tank and the inflow pipe 12.

[0023] The spray pipe is provided with a packing section 31, and a demister 32 is provided at the upper part of the packing section 31. The top of the spray pipe is provided with a crude dichloroethane liquid inlet 33 and a dichloroethane gas phase outlet 34.

[0024] The reaction process in this application is as follows:

[0025] Ethylene and chlorine enter the circulation section 1 through the ethylene inlet 13 and chlorine inlet 14, respectively. After passing through the ethylene distribution pipe 15 and chlorine distribution pipe 16, the gas enters the dichloroethane solution in the circulation section 1 through a small hole. The ethylene and chlorine are fully mixed and dissolved in the dichloroethane by the mixer 17, and dichloroethane is generated under the action of the catalyst in the reactor. All the heat generated by the reaction is used to vaporize the dichloroethane. The axial flow pump 18 provides power for the dichloroethane circulation. The axial flow pump 18 has variable frequency control to control the flow rate of the circulating liquid, ensuring the dissolution effect of ethylene and chlorine and controlling the stability of the reaction conditions. The dichloroethane solution enters the separation section 2 from the circulation section 1, where gas-liquid separation is performed. The separated gas phase enters the washing section 3 from the top of the separation section, and the liquid phase enters the inflow pipe 12 on the other side of the U-shaped pipe of the circulation section 1 after passing through the vortex breaker 21 located at the interface between the separation section 2 and the circulation section 1, and continues to circulate. The gas phase of the separation section 2 comes into countercurrent contact with the crude dichloroethane liquid entering through the crude dichloroethane liquid inlet 33 at the top of the self-washing section 3 via the packing. The liquid phase descends after passing through the separation section 2 and returns to the circulation section 1, while the gas phase rises and enters the downstream equipment through the dichloroethane gas phase outlet 34 at the top of the self-washing section 3, thereby achieving gas-liquid separation.

[0026] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-temperature chlorination reactor for the preparation of dichloroethane from ethylene chlorine gas, characterized in that: It includes a circulation section, a separation section and a washing section connected in sequence. The circulation section is a U-shaped bend, the separation section is a horizontal tank, and the washing section includes a demister, a spray pipe and a packing section. The two U-shaped ends at the top of the U-shaped bend are provided with two outlets, and the two outlets are connected to the bottom of the horizontal tank. The lower end of the spray pipe is connected to the top of the horizontal tank. The U-shaped bend consists of an outlet pipe and an inlet pipe. The lower part of the outlet pipe is provided with an ethylene inlet and a chlorine inlet. The interior of the outlet pipe is provided with an ethylene distribution pipe and a chlorine distribution pipe, which are respectively connected to the ethylene inlet and the chlorine inlet. The upper part of the ethylene distribution pipe and the chlorine distribution pipe is provided with a mixer. An axial flow pump is provided at the bend where the outlet pipe and the inlet pipe connect.

2. The high-temperature chlorination reactor for preparing dichloroethane from ethylene chlorine gas according to claim 1, characterized in that: A vortex breaker is installed at the connection between the horizontal tank and the inflow pipe.

3. The high-temperature chlorination reactor for preparing dichloroethane from ethylene chlorine gas according to claim 1, characterized in that: The spray pipe is equipped with a packing section, and a demister is provided at the top of the packing section. The top of the spray pipe is provided with a crude dichloroethane liquid inlet and a dichloroethane gas phase outlet.

4. The high-temperature chlorination reactor for preparing dichloroethane from ethylene chlorine gas according to claim 1, characterized in that: The ethylene distribution pipe is a single layer with 5 distribution pipes per layer, and small holes are opened on the distribution pipes.

5. The high-temperature chlorination reactor for preparing dichloroethane from ethylene chlorine gas according to claim 1, characterized in that: The chlorine distribution pipe has 2-4 layers, with 5 distribution pipes in each layer, and small holes are opened on the distribution pipes.

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