Method and device for producing high-purity liquid hydrogen chloride from liquid chlorine tail gas

Abstract

The invention belongs to the technical field of hydrogen chloride production methods, and particularly relates to a method and a device for producing high-purity liquid hydrogen chloride from liquid chlorine tail gas. The method for producing the high-purity liquid hydrogen chloride from the liquid chlorine tail gas comprises the following steps: mixing the liquid chlorine tail gas with hydrogen, feeding the mixture into a synthesis furnace for a synthesis reaction, cooling a crude product hydrogen chloride gas obtained by synthesis in a first-stage cooler, feeding the cooled crude product hydrogen chloride gas into a first-stage separator, and feeding the cooled crude product hydrogen chloride gas into a second-stage separator; a gas phase obtained by the first-stage separator enters a second-stage cooler to exchange heat with a tower kettle material of the refining tower and then enters a second-stage separator, a liquid phase obtained by the second-stage separator returns to the first-stage separator, an obtained gas phase enters a third-stage cooler to be cooled and then enters a third-stage separator, and a liquid phase obtained by the third-stage separator returns to the second-stage separator; the obtained gas phase is pressurized by a compressor and then sent to a refining tower for refining, and a high-purity liquid chlorinated product is extracted from a side line of the refining tower. The method for producing high-purity liquid hydrogen chloride from liquid chlorine tail gas provided by the invention has the advantages of cyclic utilization of heat energy, simple operation and high tail gas recovery rate.

Description

Technical Field

[0001] The invention belongs to the technical field of hydrogen chloride production methods, and specifically relates to a method and device for producing high-purity liquid hydrogen chloride from liquid chlorine tail gas. Background Art

[0002] There are several main methods for preparing hydrogen chloride: one is hydrochloric acid analysis, such as disclosed in patent CN107848798A, but this method has the disadvantages of long process and generation of wastewater; the second is tail gas recovery, such as disclosed in patents CN107746040A, CN1511780A, and CN101935020A, which use tail gas to prepare hydrogen chloride, but the tail gas impurities are relatively complex and subsequent refining is relatively difficult; the third is a synthesis method, such as disclosed in patent CN208200380U, which uses a complex raw material purification device and is costly. For example, as disclosed in patent CN110697656A, high-purity chlorine and high-purity hydrogen are used for preparation, and the cost is also relatively high.

[0003] After the preparation reaction of hydrogen chloride is completed, purification is the most important step. At present, the purification processes of hydrogen chloride mainly include adsorption and distillation. The adsorption method, such as the ion exchange resin disclosed in patent CN106044710A, adsorbs hydrogen and carbon dioxide in hydrogen chloride, but cannot remove other impurities. The distillation method, such as the two-stage distillation disclosed in patent CN105502295A, has a long process and high energy consumption.

[0004] Liquid chlorine tail gas treatment usually adopts alkaline solution absorption, as described in CN112295393A, and the sodium hypochlorite obtained by production and treatment is of low value.

[0005] At the same time, if the preparation process and purification process of hydrogen chloride are considered at the same time, the energy consumption of the whole process is relatively large. Therefore, it is necessary to propose a method for producing high-purity liquid hydrogen chloride using chlorine-containing tail gas to solve one of the defects in the prior art. Summary of the invention

[0006] The technical problem to be solved by the present invention is to overcome the above-mentioned defects of the prior art and provide a method for producing high-purity liquid hydrogen chloride from liquid chlorine tail gas, which has heat energy recycling, simple operation and high tail gas recovery rate.

[0007] The method for producing high-purity liquid hydrogen chloride from liquid chlorine tail gas of the present invention comprises the following steps: mixing the liquid chlorine tail gas with hydrogen, sending the mixture to a synthesis furnace for synthesis reaction, cooling the synthesized crude hydrogen chloride gas in a primary cooler and then entering a primary separator, the gas phase obtained by the primary separator entering a secondary cooler for heat exchange with materials in a refining tower kettle and then entering a secondary separator, the liquid phase obtained by the secondary separator returns to the primary separator, the gas phase obtained enters a tertiary cooler for cooling and then enters a tertiary separator, the liquid phase obtained by the tertiary separator returns to the secondary separator, the gas phase obtained is pressurized by a compressor and then sent to a refining tower for refining, and a high-purity liquid chlorination product is extracted from the side line of the refining tower.

[0008] The hydrogen chloride tail gas produced from the top gas phase of the refining tower is sent to the hydrochloric acid absorption device.

[0009] The bottom liquid obtained from the bottom of the refining tower is sent to the hydrochloric acid absorption device.

[0010] The liquid phase obtained from the primary separator is concentrated hydrochloric acid, which is recycled and used by other devices in the chlor-alkali plant. The gas phase obtained from the primary separator enters the secondary cooler and exchanges heat with the materials in the bottom of the refining tower, and then enters the secondary separator. The heat is exchanged directly, and no heat is added for distillation.

[0011] The chlorine content in liquid chlorine tail gas is 75%-95%, the hydrogen content is 3%-4%, and the total content of other components such as oxygen, nitrogen and carbon dioxide is 2%-21%.

[0012] The molar ratio of liquid chlorine tail gas to hydrogen is 1:0.8-1:1.

[0013] The temperature of the synthesis furnace is 140-170°C and the pressure is normal pressure.

[0014] The crude hydrochloric acid gas synthesized is cooled in the primary cooler to a temperature of 45-60°C. The gas phase obtained enters the tertiary cooler and is cooled to a temperature of -30°C to -35°C, and the water content is reduced to less than 10ppm. The pressure of the primary separator is normal pressure and the temperature is 45-60°C. The main function of the tertiary cooler is to remove water. The pressure of the secondary cooler is normal pressure and the temperature is -5 to 5°C. The parameter selection should be adjusted according to the temperature of the refining tower kettle. The pressure of the tertiary cooler is normal pressure and the temperature is -30 to -35°C. The water is removed from 2.4% to 10ppm, and the efficiency is 99.96%.

[0015] The refining tower pressure is 2~3MPa, the tower top temperature is -36~-45℃, and the tower bottom temperature is -3~14℃.

[0016] The synthesis device for producing high-purity liquid hydrogen chloride from liquid chlorine tail gas comprises a synthesis furnace, a primary cooler, a primary separator, a secondary cooler, a secondary separator, a tertiary cooler, a tertiary separator and a refining tower. The synthesis furnace is connected with the primary cooler, the primary cooler is connected with the primary separator, the primary separator is connected with the secondary cooler, the secondary cooler is connected with the secondary separator, the secondary separator is connected with the tertiary cooler, the tertiary cooler is connected with the tertiary separator, the tertiary separator is connected with a compressor, the compressor is connected with the refining tower, and a condenser is arranged on the top of the refining tower.

[0017] The bottom of the first-stage separator, the bottom and the top of the refining tower are all connected to the hydrochloric acid absorption device, the hydrochloric acid absorption device is connected to the hydrogen recovery device, and the hydrogen recovery device is connected to the synthesis furnace.

[0018] The synthesis furnace is provided with a liquid chlorine tail gas pipe and a hydrogen gas pipe.

[0019] The bottom of the secondary separator is connected to the primary separator.

[0020] The top of the secondary cooler is connected to the refining tower.

[0021] The bottom of the three-stage separator is connected to the two-stage separator.

[0022] The middle section of the refining tower is provided with a high-purity liquid hydrogen chloride collecting pipe.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) The method for producing high-purity liquid hydrogen chloride from liquid chlorine tail gas of the present invention has a high chlorine recovery rate for the liquid chlorine tail gas.

[0025] (2) In the method for producing high-purity liquid hydrogen chloride from liquid chlorine tail gas of the present invention, the temperature of the refining tower kettle is low, and heat exchange with the gas phase of the primary separator is used to realize secondary utilization of energy.

[0026] (3) The method for producing high-purity liquid hydrogen chloride from liquid chlorine tail gas of the present invention uses only one refining tower in the refining process, which has a short process flow and low energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The present invention is a schematic diagram of a device for producing high-purity liquid hydrogen chloride from liquid chlorine tail gas.

[0028] In the figure: 1. synthesis furnace; 2. primary cooler; 3. primary separator; 4. secondary cooler; 5. secondary separator; 6. tertiary cooler; 7. tertiary separator; 8. compressor; 9. refining tower; 10. condenser; 11. hydrochloric acid absorption device; 12. hydrogen recovery device; 13. liquid chlorine tail gas pipe; 14. hydrogen pipe; 15. hydrogen circulation pipe; 16. high-purity liquid hydrogen chloride collection pipe. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with specific embodiments.

[0030] like Figure 1 As shown, the synthesis device for producing high-purity liquid hydrogen chloride from liquid chlorine tail gas comprises a synthesis furnace 1, a primary cooler 2, a primary separator 3, a secondary cooler 4, a secondary separator 5, a tertiary cooler 6, a tertiary separator 7, and a refining tower 9. The synthesis furnace 1 is connected to the primary cooler 2, the primary cooler 2 is connected to the primary separator 3, the primary separator 3 is connected to the secondary cooler 4, the secondary cooler 4 is connected to the secondary separator 5, the secondary separator 5 is connected to the tertiary cooler 6, the tertiary cooler 6 is connected to the tertiary separator 7, the tertiary separator 7 is connected to a compressor 8, the compressor 8 is connected to the refining tower 9, and a condenser 10 is provided at the top of the refining tower 9.

[0031] The bottom of the primary separator 3 and the bottom and top of the refining tower 9 are connected to the hydrochloric acid absorber 11 . The hydrochloric acid absorber 11 is connected to the hydrogen recovery device 12 . The hydrogen recovery device 12 is connected to the synthesis furnace 1 through the hydrogen circulation pipe 15 .

[0032] The synthesis furnace 1 is provided with a liquid chlorine tail gas pipe 13 and a hydrogen pipe 14 .

[0033] The bottom of the secondary separator 5 is connected to the primary separator 3 .

[0034] The top of the secondary cooler 4 is connected to the refining tower 9 .

[0035] The bottom of the tertiary separator 7 is connected to the secondary separator 5 .

[0036] The middle section of the refining tower 9 is provided with a high-purity liquid hydrogen chloride collecting pipe 16 .

[0037] The following embodiments are all implemented using the above device.

[0038] Example 1

[0039] The liquid chlorine tail gas in this embodiment has a chlorine content of 75%, a hydrogen content of 4%, and other components, namely, oxygen, nitrogen, and carbon dioxide, with a total content of 21%.

[0040] The method for producing high-purity liquid hydrogen chloride from liquid chlorine tail gas comprises the following steps: liquid chlorine tail gas is mixed with hydrogen in a mass ratio of 1:1, and the total gas intake is 500 kg / h and sent to a synthesis furnace 1 for a synthesis reaction at 140°C and normal pressure; the synthesized crude hydrogen chloride gas is cooled in a primary cooler 2 and then enters a primary separator 3; the gas phase obtained in the primary separator 3 enters a secondary cooler 4 and exchanges heat with the bottom material of a refining tower 9 and then enters a secondary separator 5; the liquid phase obtained in the primary separator 3 is concentrated hydrochloric acid, which is recycled and used for other devices in the chlor-alkali plant. The liquid phase obtained from the secondary separator 5 returns to the primary separator 3, and the obtained gas phase enters the tertiary cooler 6 and enters the tertiary separator 7 after being cooled. The liquid phase obtained from the tertiary separator 7 returns to the secondary separator 5, and the obtained gas phase is pressurized by the compressor 8 and then sent to the refining tower 9 for refining. The high-purity liquid chlorination product is produced from the side line of the refining tower 9. The hydrogen chloride tail gas is produced from the gas phase at the top of the refining tower 9 and sent to the hydrochloric acid absorption device 11. The kettle liquid obtained in the kettle of the refining tower 9 is sent to the hydrochloric acid absorption device 11.

[0041] The gas phase obtained from the primary separator 3 enters the secondary cooler 4 and exchanges heat with the bottom material of the refining tower 9, and then enters the secondary separator, which directly exchanges heat and does not require additional heat for distillation.

[0042] The crude hydrochloric acid gas synthesized is cooled in the primary cooler 2 to a temperature of 60°C. The gas phase obtained enters the tertiary cooler 6 for cooling, and the water content is reduced to less than 10ppm. The pressure of the primary separator 3 is normal pressure and the temperature is 60°C. The main function of the tertiary cooler 6 is to remove water. The pressure of the secondary cooler 4 is normal pressure and the temperature is 0°C. The parameter selection should be adjusted according to the temperature of the kettle of the refining tower 9. The pressure of the tertiary cooler 6 is normal pressure and the temperature is -30°C. The water is removed from 2.4% to 10ppm, and the efficiency is 99.96%.

[0043] The pressure of refining tower 9 is 2.0 MPa, the top temperature is -45°C, and the bottom temperature is -3°C.

[0044] The purity of the hydrogen chloride prepared in this embodiment is 99.96%.

[0045] Example 2

[0046] The liquid chlorine tail gas in this embodiment has a chlorine content of 90%, a hydrogen content of 4%, and other components such as oxygen, nitrogen, and carbon dioxide with a total content of 6%.

[0047] The method for producing high-purity liquid hydrogen chloride from liquid chlorine tail gas comprises the following steps: liquid chlorine tail gas is mixed with hydrogen in a mass ratio of 1:0.8, and the total gas intake is 300 kg / h and sent to a synthesis furnace 1 for a synthesis reaction at 150°C and normal pressure; the synthesized crude hydrogen chloride gas is cooled in a primary cooler 2 and then enters a primary separator 3; the gas phase obtained in the primary separator 3 enters a secondary cooler 4 and exchanges heat with the bottom material of a refining tower 9 and then enters a secondary separator 5; the liquid phase obtained in the primary separator 3 is concentrated hydrochloric acid, which is recycled and used for other devices in the chlor-alkali plant. The liquid phase obtained from the secondary separator 5 returns to the primary separator 3, and the obtained gas phase enters the tertiary cooler 6 and enters the tertiary separator 7 after being cooled. The liquid phase obtained from the tertiary separator 7 returns to the secondary separator 5, and the obtained gas phase is pressurized by the compressor 8 and then sent to the refining tower 9 for refining. The high-purity liquid chlorination product is produced from the side line of the refining tower 9. The hydrogen chloride tail gas is produced from the gas phase at the top of the refining tower 9 and sent to the hydrochloric acid absorption device 11. The kettle liquid obtained in the kettle of the refining tower 9 is sent to the hydrochloric acid absorption device 11.

[0048] The gas phase obtained from the primary separator 3 enters the secondary cooler 4 and exchanges heat with the bottom material of the refining tower 9, and then enters the secondary separator, which directly exchanges heat and does not require additional heat for distillation.

[0049] The crude hydrochloric acid gas synthesized is cooled in the primary cooler 2 to a temperature of 50°C. The gas phase obtained enters the tertiary cooler 6 for cooling, and the water content is reduced to less than 10ppm. The pressure of the primary separator 3 is normal pressure and the temperature is 50°C. The main function of the tertiary cooler 6 is to remove water. The pressure of the secondary cooler 4 is normal pressure and the temperature is -5°C. The parameter selection should be adjusted according to the temperature of the kettle of the refining tower 9. The pressure of the tertiary cooler 6 is normal pressure and the temperature is -30°C. The water is removed from 2.8% to 10ppm, and the efficiency is 99.97%.

[0050] The pressure of refining tower 9 is 3.0 MPa, the top temperature is -36°C, and the bottom temperature is 14°C.

[0051] The purity of the hydrogen chloride prepared in this embodiment is 99.97%.

[0052] Example 3

[0053] The liquid chlorine tail gas in this embodiment has a chlorine content of 90%, a hydrogen content of 3%, and other components, namely, oxygen, nitrogen, and carbon dioxide, with a total content of 7%.

[0054] The method for producing high-purity liquid hydrogen chloride from liquid chlorine tail gas comprises the following steps: liquid chlorine tail gas is mixed with hydrogen in a mass ratio of 1:1, and the total gas intake is 300 kg / h and sent to a synthesis furnace 1 for synthesis reaction at 170°C and normal pressure; the synthesized crude hydrogen chloride gas is cooled in a primary cooler 2 and then enters a primary separator 3; the gas phase obtained in the primary separator 3 enters a secondary cooler 4 and exchanges heat with the bottom material of a refining tower 9 and then enters a secondary separator 5; the liquid phase obtained in the primary separator 3 is concentrated hydrochloric acid, which is recycled and used for other devices in the chlor-alkali plant. The liquid phase obtained from the secondary separator 5 returns to the primary separator 3, and the obtained gas phase enters the tertiary cooler 6 and enters the tertiary separator 7 after being cooled. The liquid phase obtained from the tertiary separator 7 returns to the secondary separator 5, and the obtained gas phase is pressurized by the compressor 8 and then sent to the refining tower 9 for refining. The high-purity liquid chlorination product is produced from the side line of the refining tower 9. The hydrogen chloride tail gas is produced from the gas phase at the top of the refining tower 9 and sent to the hydrochloric acid absorption device 11. The kettle liquid obtained in the kettle of the refining tower 9 is sent to the hydrochloric acid absorption device 11.

[0055] The gas phase obtained from the primary separator 3 enters the secondary cooler 4 and exchanges heat with the bottom material of the refining tower 9, and then enters the secondary separator, which directly exchanges heat and does not require additional heat for distillation.

[0056] The crude hydrochloric acid gas synthesized is cooled in the primary cooler 2 to a temperature of 45°C. The gas phase obtained enters the tertiary cooler 6 for cooling, and the water content is reduced to less than 10ppm. The pressure of the primary separator 3 is normal pressure and the temperature is 45°C. The main function of the tertiary cooler 6 is to remove water. The pressure of the secondary cooler 4 is normal pressure and the temperature is -5°C. The parameter selection should be adjusted according to the temperature of the kettle of the refining tower 9. The pressure of the tertiary cooler 6 is normal pressure and the temperature is -35°C. The water is removed from 2.7% to 9ppm, and the efficiency is 99.97%.

[0057] The pressure of refining tower 9 is 2.2MPa, the top temperature is -43°C, and the bottom temperature is 2°C.

[0058] The purity of the hydrogen chloride prepared in this embodiment is 99.97%.

[0059] Comparative Example 1

[0060] The raw material of the high-purity hydrogen chloride production method disclosed in patent CN105502295A is 99% ready-made industrial-grade HCl. This method does not involve the synthesis process of HCl, but only the refining of hydrogen chloride, and cannot be compared in all aspects. The refining process of this method requires a two-stage distillation tower, and after the distillation is completed, a three-stage series adsorption tower is required to produce high-purity hydrogen chloride. If the subsequent adsorption process is not considered, only from the perspective of distillation, the process is longer than the present invention, and the purpose of this equipment is to produce electronic-grade hydrogen chloride. The equipment is highly complex, resulting in a large investment in production equipment. The product of the present invention is positioned as ordinary high-purity hydrogen chloride. If the subsequent impurity removal adsorption process is continued to be added, a high-purity electronic-grade hydrogen chloride product can also be obtained. The present invention currently does not include a subsequent further refining process.

[0061] Further compare the energy consumption of the distillation production process, according to the first distillation tower described in Example 3, the number of theoretical plates is 12, the distillation pressure is 15 bar, the top temperature is -30 ° C, the bottom temperature is -10 ° C, and the top of the tower is fully refluxed; the second distillation tower has 12 theoretical plates, a distillation pressure of 15 bar, a top temperature of -30 ° C, a bottom temperature of -10 ° C, a top reflux ratio of 2.5, and the inlet gas is set to 300 kg / h of 99% purity industrial grade HCl. Its operating parameters should be incorrect, and the top or bottom temperature does not match the boiling point of the corresponding high-purity HCl at a pressure of 15 bar. If the energy consumption of the distillation process is estimated based on its operating pressure of 15 bar, the product reaches the purity of 99.97% of the liquid hydrogen chloride described in Example 3 of the present invention, and the energy consumption of the bottom reboiler and the top condenser included therein is estimated to be about 350 kw and 170 kw respectively according to the heat exchange.

[0062] The one-stage distillation tower used in the present invention is one stage less than that in the above-mentioned invention. At the same time, because the synthesis gas cooling heat coupling process is combined, the tower bottom reboiler does not need to supply an additional heat source, and the secondary cooling of the synthesis gas does not need additional cooling water. Only the energy consumption required for the condensation at the top of the distillation tower and the primary and tertiary cooling of the synthesis gas needs to be considered. Referring to the operating conditions described in Example 3, the required cooling heat exchange is calculated to be approximately 80kw.

[0063] From the comparison of energy consumption of the refining process of the above two methods, it can be seen that the energy consumption required by the present invention is lower.

[0064] Comparative Example 2

[0065] Compared with the high-purity hydrogen chloride production device described in patent CN110697656A, its raw materials are high-purity hydrogen and high-purity chlorine, which have fewer impurities and relatively lower requirements for subsequent refining processes, but the cost of raw materials is high. The present invention uses general chlorine tail gas as raw material, which belongs to waste gas recycling, and the hydrogen raw material can also use general industrial grade hydrogen, and the raw material source is easy to obtain and economical.

[0066] The high-purity hydrogen chloride production device described in patent CN110697656A needs to pass through the cooling tower, condensing tower, re-gasification, and deep separation purifier in sequence after passing through the synthesis furnace. The deep separation purifier uses a certain ratio of deep separation filler and contains a self-made resin with a unique production process. It is not a large-scale industrial-grade filler and is currently difficult to purchase from the market.

[0067] The present invention can obtain the hydrogen chloride product after passing through the synthesis furnace, the common heat exchanger and the separation container, and then the pressure is increased and enters the distillation tower, thereby reducing the number of complex towers, and there is no need to use complex specific chemicals and complex accessories and materials in the process, thereby reducing the requirements for equipment and raw materials in production.

[0068] Of course, the above contents are only preferred embodiments of the present invention and cannot be considered to limit the scope of the embodiments of the present invention. The present invention is not limited to the above examples, and equal changes and improvements made by ordinary technicians in the technical field within the essential scope of the present invention should all fall within the scope of the patent coverage of the present invention.

Claims

1. A method for producing high-purity liquid hydrogen chloride from liquid chlorine tail gas, characterized in that: The following steps are involved: Liquid chlorine tail gas is mixed with hydrogen and sent to a synthesis furnace (1) for synthesis reaction. The synthesized crude hydrogen chloride gas is cooled in a primary cooler (2) and then enters a primary separator (3). The gas phase obtained in the primary separator (3) enters a secondary cooler (4) and then enters a secondary separator (5) after heat exchange with the bottom material of a refining tower (9). The liquid phase obtained in the secondary separator (5) returns to the primary separator (3). The gas phase obtained enters a tertiary cooler (6) and then enters a tertiary separator (7) after cooling. The liquid phase obtained in the tertiary separator (7) returns to the secondary separator (5). The gas phase obtained is pressurized by a compressor (8) and then sent to a refining tower (9) for refining. A high-purity liquid chlorination product is extracted from the side line of the refining tower (9).

2. The method for producing high-purity liquid hydrogen chloride from liquid chlorine tail gas according to claim 1, characterized in that: The hydrogen chloride tail gas extracted from the top gas phase of the refining tower (9) is sent to the hydrochloric acid absorption device (11).

3. The method for producing high-purity liquid hydrogen chloride from liquid chlorine tail gas according to claim 1, characterized in that: The bottom liquid obtained in the bottom of the refining tower (9) is sent to the hydrochloric acid absorption device (11).

4. The method for producing high-purity liquid hydrogen chloride from liquid chlorine tail gas according to claim 1, characterized in that: The liquid phase obtained from the primary separator (3) is concentrated hydrochloric acid, which is recycled.

5. The method for producing high-purity liquid hydrogen chloride from liquid chlorine tail gas according to claim 1, characterized in that: The chlorine content in liquid chlorine tail gas is 75%-95%, the hydrogen content is 3%-4%, and the other components are oxygen, nitrogen, and carbon dioxide with a total content of 2%-21%.

6. The method for producing high-purity liquid hydrogen chloride from liquid chlorine tail gas according to claim 1, characterized in that: The molar ratio of liquid chlorine tail gas to hydrogen is 1:0.8-1:

1.

7. The method for producing high-purity liquid hydrogen chloride from liquid chlorine tail gas according to claim 1, characterized in that: The crude hydrogen chloride gas obtained by synthesis is cooled in the primary cooler (2) to a temperature of 45-60°C, and the obtained gas phase enters the tertiary cooler (6) to a temperature of -30°C to -35°C after cooling, and the water content is reduced to less than 10 ppm.

8. The method for producing high-purity liquid hydrogen chloride from liquid chlorine tail gas according to claim 1, characterized in that: The refining tower (9) has a pressure of 2 to 3 MPa, a top temperature of -36 to -45°C, and a bottom temperature of -3 to 14°C.

9. A device for producing high-purity liquid hydrogen chloride from liquid chlorine tail gas, characterized in that: The invention comprises a synthesis furnace (1), a primary cooler (2), a primary separator (3), a secondary cooler (4), a secondary separator (5), a tertiary cooler (6), a tertiary separator (7), and a refining tower (9). The synthesis furnace (1) is connected to the primary cooler (2), the primary cooler (2) is connected to the primary separator (3), the primary separator (3) is connected to the secondary cooler (4), the secondary cooler (4) is connected to the secondary separator (5), the secondary separator (5) is connected to the tertiary cooler (6), the tertiary cooler (6) is connected to the tertiary separator (7), the tertiary separator (7) is connected to a compressor (8), the compressor (8) is connected to the refining tower (9), and a condenser (10) is arranged at the top of the refining tower (9).

10. The device for producing high-purity liquid hydrogen chloride from liquid chlorine tail gas according to claim 9, characterized in that: The bottom of the primary separator (3) and the bottom and top of the refining tower (9) are connected to a hydrochloric acid absorption device (11), the hydrochloric acid absorption device (11) is connected to a hydrogen recovery device (12), and the hydrogen recovery device (12) is connected to a synthesis furnace (1).

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