Device for continuously removing hydrogen fluoride from industrial hydrogen chloride tail gas

Abstract

The utility model relates to a device for continuously removing hydrogen fluoride from industrial hydrogen chloride tail gas and belongs to the field of chemical equipment. The device comprises a static mixer, one end of the static mixer is sequentially connected with a gas-liquid separation device, a condenser and a hydrogen chloride gas outlet, and the other end of the static mixer is connected with a Venturi nozzle; the gas-liquid separation device is connected with a liquid circulation loop and a gas circulation loop, the gas circulation loop is provided with a hydrogen chloride gas inlet and is connected with the Venturi nozzle, and the liquid circulation loop is connected with the Venturi nozzle through a circulation pump. The hydrogen fluoride content in the hydrogen chloride tail gas can be reduced to below 5ppm, and the device has the advantages of simplicity in operation and environment friendliness.

Description

Technical Field

[0001] This utility model relates to a device for continuous defluorination of hydrogen chloride tail gas in industrial applications, belonging to the field of chemical equipment. Background Technology

[0002] With the development of the domestic economy and the improvement of residents' living standards, the fluorochemical industry, mainly producing refrigerant products, has achieved rapid development in recent years. However, fluorochemical production generates a large amount of hydrochloric acid, a byproduct containing hydrogen fluoride. The presence of hydrogen fluoride in hydrochloric acid greatly enhances its corrosiveness, limiting the application of this byproduct and severely impacting its economic benefits. Furthermore, with increasingly stringent environmental protection requirements, the need to treat hydrogen fluoride in hydrochloric acid is becoming increasingly urgent, necessitating the search for a low-cost, high-efficiency defluorination method.

[0003] Currently, the main defluorination methods used by enterprises include precipitation, distillation, adsorption, and membrane separation. Based on the different defluorination processes, they can be divided into dry defluorination and wet defluorination. Dry defluorination utilizes solid defluorinating agents to selectively absorb HF impurities in the byproduct HCl gas. Solid defluorinating agents reported in the literature include Al2O3, SiO2, CaCl2, and CaO. However, dry defluorination has two problems: first, the defluorination capacity of dry defluorinating agents is generally low, resulting in high usage costs; second, the defluorinating agent generates a large amount of solid waste after its deterioration, increasing environmental concerns. Wet defluorination utilizes solvents to selectively adsorb HF impurities in the byproduct HCl. The solvent used can be recycled after the impurities are removed.

[0004] The defluorination equipment used in defluorination processes mainly includes batch reactors and circulating reflux reactors, such as CN219898074U. However, existing defluorination equipment still cannot fully mix the defluorinated materials, thus affecting the defluorination efficiency. Summary of the Invention

[0005] In view of the current state of the prior art, this invention, through in-depth and extensive research in the field of industrial hydrogen chloride tail gas defluorination, has discovered that using a loop reactor that enhances the gas-liquid two-phase mixing effect as the defluorination device, and adding a static mixer inside the reactor to further enhance the gas-liquid two-phase mixing effect, can greatly improve the defluorination efficiency and enable continuous defluorination operations, making it suitable for industrial applications. Furthermore, by using a suitable defluorination agent composition, including chlorosilane defluorinators and catalysts, the defluorination treatment time can be significantly shortened.

[0006] Therefore, the purpose of this invention is to provide a device for continuous defluorination of industrial hydrogen chloride tail gas. Based on the dual circulation mixing of hydrogen chloride gas circulation loop and defluorinating agent liquid circulation loop, the device further promotes the mixing and exchange of hydrogen chloride tail gas and defluorinating agent by adding a static mixer in the middle of the reactor.

[0007] The technical solution for achieving the above-mentioned utility model objective can be summarized as follows:

[0008] An apparatus for continuous defluorination of industrial hydrogen chloride tail gas includes a static mixer. One end of the static mixer is sequentially connected to a gas-liquid separator, a condenser, and a hydrogen chloride gas outlet. The other end of the static mixer is connected to a Venturi nozzle. The gas-liquid separator is connected to a liquid circulation loop and a gas circulation loop. The gas circulation loop is provided with a hydrogen chloride gas inlet and is connected to the Venturi nozzle. The liquid circulation loop is connected to the Venturi nozzle through a circulation pump.

[0009] According to this utility model, preferably, the static mixer is a cylindrical structure, and the cylindrical structure is provided with one or more perforated plates, more preferably 3-9; preferably, the perforated plates are arranged radially along the cylinder or at an angle to the radial direction.

[0010] Preferably, the aspect ratio of the static mixer is 100:1 to 10.

[0011] According to this utility model, preferably, a gas check valve is provided between the hydrogen chloride gas inlet and the gas-liquid separation device.

[0012] According to this utility model, preferably, a buffer zone is also provided between the static mixer and the Venturi nozzle.

[0013] According to this utility model, preferably, the device for continuous defluorination of industrial hydrogen chloride tail gas is a column reactor structure. The column reactor is divided into three sections: a buffer section, a mixing section, and a separation section. The buffer section is the buffer section, the static mixer and Venturi nozzle are the mixing section, and the gas-liquid separator and condenser are the separation section.

[0014] According to this utility model, preferably, at least one of the buffer zone, static mixer, venturi nozzle and gas-liquid separation device is provided with a heating device for heating the defluorination reaction.

[0015] According to this utility model, preferably, the device for continuous defluorination of industrial hydrogen chloride tail gas is a closed pressure device that can adapt to high-pressure reactions.

[0016] Compared with the prior art, the advantages of this utility model are:

[0017] 1. High reaction efficiency. Based on the dual-circulation mixing of hydrogen chloride gas circulation loop and defluorinating agent liquid circulation loop, this invention promotes the mixing and exchange of hydrogen chloride tail gas and defluorinating agent composition by adding a static mixer in the middle of the device, further enhancing the mixing effect of the gas and liquid phases, which can greatly improve the defluorination efficiency.

[0018] 2. Simple process. This utility model can achieve continuous operation without additional operations, significantly simplifying the operation process and allowing for long continuous working time. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the main structure of the device for continuous defluorination of industrial hydrogen chloride tail gas according to this utility model.

[0020] Figure 2 This is a schematic diagram of the main structure of the static mixer of this utility model.

[0021] The components are: 1. Hydrogen chloride gas outlet, 2. Condenser, 3. Gas-liquid separation device, 4. Liquid circulation loop, 5. Static mixer, 6. Buffer zone, 7. Circulation pump, 8. Venturi nozzle, 9. Gas circulation loop, 10. Hydrogen chloride gas inlet, 11. Gas check valve, 12. Orifice plate. Detailed Implementation

[0022] This invention, based on a dual-circulation mixing system of hydrogen chloride gas and defluorinating agent liquid, promotes the mixing and exchange of hydrogen chloride tail gas and defluorinating agent by adding a static mixer in the middle of the reactor. It can be further combined with a defluorinating agent composition to accelerate the rate of fluorine substitution for chlorine, effectively suppress the volatilization of fluorinated organic compounds, and make the treated hydrogen chloride tail gas purer, thus achieving the best defluorination effect.

[0023] The present invention relates to a device for continuous defluorination of industrial hydrogen chloride tail gas, comprising a static mixer 5, one end of which is sequentially connected to a gas-liquid separator 3, a condenser 2, and a hydrogen chloride gas outlet 1, and the other end of which is connected to a Venturi nozzle 8; the gas-liquid separator 3 is connected to a liquid circulation loop 4 and a gas circulation loop 9, the gas circulation loop 9 is provided with a hydrogen chloride gas inlet 10 and is connected to the Venturi nozzle 8, and the liquid circulation loop 4 is connected to the Venturi nozzle 8 through a circulation pump 7.

[0024] In one or more preferred embodiments, the static mixer 5 is a cylindrical structure, with one or more perforated plates 12 disposed inside the cylindrical structure, more preferably 3-9. The perforated plates 12 are plates with uniformly distributed perforations, and their shape is adapted to the interior of the static mixer 5. The purpose of the perforated plates 12 is to ensure thorough mixing of the hydrogen chloride tail gas and the defluorinating agent composition. The perforated plates 12 can be arranged radially along the cylinder or at a certain angle to the radial direction. To achieve a good mixing effect, the static mixer 5 can be an elongated structure, which increases the contact time of the mixed gases, thereby increasing the mixing effect and reaction efficiency. More preferably, the length-to-diameter ratio of the static mixer 5 is 100:1 to 10.

[0025] According to this utility model, the hydrogen chloride gas inlet 10 is connected to the gas-liquid separation device 3. In order to control the flow direction and flow rate of the hydrogen chloride gas, a one-way gas valve can be set. In one or more preferred embodiments, a one-way gas valve 11 is provided between the hydrogen chloride gas inlet 10 and the gas-liquid separation device 3.

[0026] According to this invention, the Venturi nozzle 8 is a highly effective mixing component. To prevent the jet airflow from the Venturi nozzle 8 from impacting the static mixer 5 and to achieve a better mixing effect, a buffer area is provided at the outlet of the Venturi nozzle 8. In one or more preferred embodiments, a buffer zone 6 is further provided between the static mixer 5 and the Venturi nozzle 8.

[0027] According to this utility model, the device for continuous defluorination of industrial hydrogen chloride tail gas can be a column reactor structure. The column reactor is in three sections: a buffer section, a mixing section, and a separation section. The buffer section is 6, the static mixer 5 and the Venturi nozzle 8 are the mixing section, and the gas-liquid separator 3 and the condenser 2 are the separation section.

[0028] According to this invention, the defluorination reaction can be carried out under certain temperature and pressure conditions, and the device for continuous defluorination of industrial hydrogen chloride tail gas can be equipped with a heating component. In one or more preferred embodiments, at least one of the buffer zone 6, static mixer 5, venturi nozzle 8, and gas-liquid separator 3 is equipped with a heating device for heating the defluorination reaction. The device for continuous defluorination of industrial hydrogen chloride tail gas can be a completely closed pressure device, suitable for high-pressure reactions.

[0029] The device for continuous defluorination of industrial hydrogen chloride tail gas according to this utility model is used as follows:

[0030] A defluorinating agent composition can be added to the device for continuous defluorination of industrial hydrogen chloride tail gas in advance. After the circulation pump 7 is started and the liquid forms a circulation loop, the device is heated to a certain temperature. After reaching the preset temperature, industrial hydrogen chloride tail gas is introduced into the device from the hydrogen chloride gas inlet 10. The gas enters the buffer zone 6 through the gas circulation loop 9 and the Venturi nozzle 8. The defluorinating agent composition enters the buffer zone 6 through the liquid circulation loop 4, the circulation pump 7 and the Venturi nozzle 8. After the hydrogen chloride tail gas and the defluorinating agent composition are mixed in the buffer zone 6, they enter the static mixer 5 simultaneously, and then enter the gas-liquid separation device 3. The separated hydrogen chloride gas is condensed by the condenser 2 and discharged from the hydrogen chloride outlet 1.

[0031] Unless otherwise described in this utility model, all provisions shall be made in accordance with the prior art in this field.

[0032] The present invention will be further described below with reference to specific implementation examples, but the present invention is not limited to these specific embodiments. Those skilled in the art should recognize that the present invention covers all alternative solutions, improvements, and equivalent solutions that may be included within the scope of the claims.

[0033] Example 1

[0034] like Figure 1 , Figure 2 As shown, the device for continuous defluorination of industrial hydrogen chloride tail gas includes a static mixer 5. One end of the static mixer 5 is sequentially connected to a gas-liquid separator 3, a condenser 2, and a hydrogen chloride gas outlet 1. The other end of the static mixer 5 is connected to a Venturi nozzle 8. The gas-liquid separator 3 is connected to a liquid circulation loop 4 and a gas circulation loop 9. The gas circulation loop 9 is provided with a hydrogen chloride gas inlet 10 and is connected to the Venturi nozzle 8. The liquid circulation loop 4 is connected to the Venturi nozzle 8 through a circulation pump 7.

[0035] In this embodiment, the static mixer 5 is a cylindrical structure with a length-to-diameter ratio of 100:5, and five circular perforated plates 12 are arranged radially inside the cylindrical structure.

[0036] Example 2

[0037] As described in Example 1, the difference is:

[0038] A gas check valve 11 is provided between the hydrogen chloride gas inlet 10 and the gas-liquid separator 3. In this embodiment, the static mixer 5 is a cylindrical structure with a length-to-diameter ratio of 100:1, and nine circular perforated plates 12 are arranged radially inside the cylindrical structure.

[0039] Example 3

[0040] As described in Example 1 or 2, the difference is:

[0041] A buffer zone 6 is also provided between the static mixer 5 and the Venturi nozzle 8. In this embodiment, the static mixer 5 is a cylindrical structure with a length-to-diameter ratio of 100:10. The cylindrical structure has three circular orifice plates 12 inside, and the circular orifice plates 12 are at a 45° angle to the radial direction. At least one of the buffer zone 6, the static mixer 5, the Venturi nozzle 8, and the gas-liquid separation device 3 is equipped with a heating device.

[0042] The device in this embodiment is a column reactor structure, which is a closed pressure device. The column reactor is divided into three sections: a buffer section, a mixing section, and a separation section. The buffer section is the buffer section, the static mixer 5 and the Venturi nozzle 8 are the mixing section, and the gas-liquid separator 3 and the condenser 2 are the separation section.

[0043] Test case

[0044] The continuous defluorination device for industrial hydrogen chloride tail gas described in Examples 1, 2, or 3 is used for defluorination. A defluorinating agent composition is added to the device beforehand. The circulation pump 7 is started, and the device is heated to the preset temperature after the liquid forms a circulation loop. Then, industrial hydrogen chloride tail gas is introduced into the device through the hydrogen chloride gas inlet 10. The gas enters the buffer zone 6 through the gas circulation loop 9 and the Venturi nozzle 8. The defluorinating agent composition enters the buffer zone 6 through the liquid circulation loop 4, the circulation pump 7, and the Venturi nozzle 8. After mixing in the buffer zone 6, the hydrogen chloride tail gas and the defluorinating agent composition simultaneously enter the static mixer 5, and then the gas-liquid separator 3. The separated hydrogen chloride gas is condensed by the condenser 2 and discharged from the hydrogen chloride outlet 1.

[0045] The specific steps are as follows:

[0046] (1) 25L of decyltrichlorosilane and 500g of tridecyl tertiary amine were added to the reactor as a defluorination agent composition;

[0047] (2) Start the circulation pump 7, and the liquid begins to circulate in the reactor to preheat the reactor;

[0048] (3) When the temperature rises to 70℃, start introducing industrial hydrogen chloride tail gas from hydrogen chloride gas inlet 10, and control the hydrogen chloride gas inlet speed to be 30g / min.

[0049] (4) When the pressure inside the reactor reaches 1 MPa, open hydrogen chloride gas outlet 1 to control the pressure inside the reactor to 1 MPa;

[0050] (5) Work continuously for 500 hours, and take samples for testing every hour.

[0051] A sample was taken after 5 minutes of continuous operation and analyzed by a fluoride ion electrode. The results showed that the hydrogen fluoride content in the inlet gas was 153 ppm and the hydrogen fluoride content in the outlet gas was 1.3 ppm; the defluorination efficiency was 99.15%.

[0052] Compared to traditional loop reactors, this invention, by setting up a static mixer 5, can greatly promote the mixing reaction of the gas and liquid phases inside the reactor, prolong the residence time of the gas and liquid phases, and improve the defluorination efficiency.

[0053] Comparative Example 1

[0054] In this comparative example, the reactor is a conventional loop reactor. No static mixer is installed in the main reactor. The main reaction zone volume is 25 liters. The operating procedure is as follows:

[0055] (1) 25L of decyltrichlorosilane was added to the reactor as a defluorinating agent;

[0056] (2) Start the circulation pump, and the liquid begins to circulate in the reactor to preheat the reactor;

[0057] (3) When the temperature rises to 70℃, industrial hydrogen chloride tail gas is introduced from the hydrogen chloride gas inlet, and the hydrogen chloride gas inlet speed is controlled to be 30g / min.

[0058] (4) When the pressure inside the reactor reaches 1 MPa, open the hydrogen chloride gas outlet and control the pressure inside the reactor to 1 MPa;

[0059] (5) Work continuously for 500 hours, and take samples for testing every hour.

[0060] A sample taken after 5 minutes of continuous operation was analyzed by a fluoride ion electrode. The results showed that the hydrogen fluoride content in the inlet gas was 147 ppm and the hydrogen fluoride content in the outlet gas was 15.2 ppm; the defluorination efficiency was 91.02%.

[0061] Comparative Example 2

[0062] In this comparative example, the reactor is a continuous stirred tank reactor with a main reaction zone volume of 25 liters. The operating procedure is as follows:

[0063] (1) 25L of decyltrichlorosilane was added to the reactor as a defluorinating agent;

[0064] (2) Start stirring and preheat the reactor;

[0065] (3) When the temperature rises to 70°C, start introducing industrial hydrogen chloride tail gas from the bottom of the reactor and control the hydrogen chloride intake rate to 30 g / min.

[0066] (4) When the pressure inside the reactor reaches 1 MPa, open the hydrogen chloride gas outlet at the top of the reactor and control the pressure inside the reactor to 1 MPa;

[0067] (5) Work continuously for 500 hours, and take samples for testing every hour.

[0068] A sample was taken after 5 minutes of continuous operation and analyzed by a fluoride ion electrode. The results showed that the hydrogen fluoride content in the inlet gas was 151 ppm and the hydrogen fluoride content in the outlet gas was 61.3 ppm; the defluorination efficiency was 59.40%.

Claims

1. A device for continuous defluorination of industrial hydrogen chloride tail gas, characterized in that, The device includes a static mixer (5), one end of which is connected in sequence to a gas-liquid separator (3), a condenser (2) and a hydrogen chloride gas outlet (1), and the other end of which is connected to a Venturi nozzle (8); the gas-liquid separator (3) is connected to a liquid circulation loop (4) and a gas circulation loop (9), the gas circulation loop (9) is provided with a hydrogen chloride gas inlet (10) and is connected to the Venturi nozzle (8), and the liquid circulation loop (4) is connected to the Venturi nozzle (8) through a circulation pump (7).

2. The apparatus for continuous defluorination of industrial hydrogen chloride tail gas according to claim 1, characterized in that, The static mixer (5) is a cylindrical structure, and one or more perforated plates (12) are provided inside the cylindrical structure.

3. The apparatus for continuous defluorination of industrial hydrogen chloride tail gas according to claim 2, characterized in that, The number of orifice plates (12) is 3-9.

4. The apparatus for continuous defluorination of industrial hydrogen chloride tail gas according to claim 2, characterized in that, The perforated plate (12) is set radially along the cylinder or at an angle to the radial direction.

5. The apparatus for continuous defluorination of industrial hydrogen chloride tail gas according to claim 2, characterized in that, The aspect ratio of the static mixer (5) is 100:1~10.

6. The apparatus for continuous defluorination of industrial hydrogen chloride tail gas according to any one of claims 1-5, characterized in that, A buffer zone (6) is also provided between the static mixer (5) and the venturi nozzle (8).

7. The apparatus for continuous defluorination of industrial hydrogen chloride tail gas according to claim 6, characterized in that, A gas check valve (11) is installed between the hydrogen chloride gas inlet (10) and the gas-liquid separation device (3).

8. The apparatus for continuous defluorination of industrial hydrogen chloride tail gas according to claim 7, characterized in that, At least one of the buffer zone (6), static mixer (5), venturi nozzle (8) and gas-liquid separator (3) is provided with a heating device.

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