Purification system of high-purity hydrogen chloride

Abstract

The utility model relates to a purification system of high-purity hydrogen chloride and belongs to the field of hydrogen chloride purification. The wet hydrogen chloride gas is dried through sulfuric acid in the first step, most of water in the wet hydrogen chloride gas is removed, then the dried wet hydrogen chloride gas is dehydrated through the hydrogen chloride molecular sieve, the hydrogen chloride molecular sieve can resist acid corrosion, and compared with a traditional molecular sieve dryer, the drying efficiency is improved. The system for purifying the high-purity hydrogen chloride gas has excellent dehydration performance and corrosion resistance, so that the water content in the wet hydrogen chloride gas can be reduced, low-boiling-point gas in the wet hydrogen chloride gas is further removed through rectification, and finally the high-purity hydrogen chloride with the purity larger than or equal to 99.5% is obtained. The method is suitable for large-scale industrial production.

Description

Technical Field

[0001] The utility model relates to the field of hydrogen chloride purification, in particular to a high-purity hydrogen chloride purification system. Background Art

[0002] Hydrogen chloride is a colorless gas with a pungent odor and a chemical formula of HCl. It has the characteristics of good thermal stability, being easily soluble in water, soluble in various organic solvents such as ethanol, and not burning in the air. It is widely used in the fields of industry, chemical industry, textile, metallurgy, electronics, medicine, etc. According to the purity of hydrogen chloride, hydrogen chloride can be divided into industrial grade hydrogen chloride and electronic grade hydrogen chloride. Among them, electronic grade hydrogen chloride gas refers to high-purity hydrogen chloride gas with a purity higher than 99.999% used in the electronics field. With the development of science and technology, the market's requirements for product quality have increased, and the requirements for raw materials have become increasingly stringent, and the purity of hydrogen chloride has also increased successively. The production processes of high-purity hydrogen chloride include desorption method, hydrochloric acid desorption method, synthesis method, industrial by-product acid desorption method, etc.

[0003] CN106276796B discloses a method for preparing high-purity hydrogen chloride. An ultra-high cross-linked polystyrene adsorption resin synthesized by a chloromethyl post-cross-linking process is used as an adsorbent. Chlorine gas enters a combined furnace to synthesize hydrogen chloride, and then enters an adsorption tower equipped with an adsorbent for refined dechlorination. The adsorbed hydrogen chloride gas is then cooled and liquefied to remove hydrogen and non-condensable gases to obtain a high-purity hydrogen chloride product.

[0004] CN105502294B discloses a high-pressure preparation method for electronic-grade high-purity hydrogen chloride, including a sulfuric acid drying process, a low-pressure adsorption process, a distillation process and a THC adsorption process. The low-pressure adsorption process is that the hydrogen chloride gas treated by the sulfuric acid drying process enters the first-stage compression, the pressure is 0.5-1.0MPaG, and the temperature is 20-40°C; the distillation process is that the hydrogen chloride treated by the low-pressure adsorption process enters the secondary compression and condensation system, the hydrogen chloride gas is compressed to 4.5-5.5MPaG, cooled to 10-30°C, and enters the dehydrogenation distillation tower. The high-pressure preparation method for electronic-grade high-purity hydrogen chloride described in the present invention fully recovers cold capacity and reduces energy consumption through pressurized condensation and reduced-pressure refrigeration, thereby achieving energy saving, economy and environmental protection.

[0005] In summary, the purification effect of industrial hydrogen chloride purification process is poor, and the operation steps are complicated, which increases the cost of industrial purification of hydrogen chloride. In addition, the current traditional molecular sieves are not resistant to the corrosion of hydrogen chloride. Therefore, the drying of hydrogen chloride in the prior art is difficult, the purity is low, and the production cost is high, which is still a problem to be solved urgently. Utility Model Content

[0006] In view of the above problems, the utility model provides a high-purity hydrogen chloride purification system, which obtains high-purity hydrogen chloride by drying, compressing and distilling hydrogen chloride. The purification process is simple to operate, green and environmentally friendly, and simple to operate, and is suitable for industrial production.

[0007] The utility model provides a purification system for high-purity hydrogen chloride. According to the flow direction of wet hydrogen chloride gas, the purification system comprises a drying unit, a compression unit and a distillation unit, wherein the drying unit comprises a preheater, a primary sulfuric acid tower, a secondary sulfuric acid tower, a concentrated sulfuric acid tank, a waste sulfuric acid tank, a demister, a primary molecular sieve drying tower, a secondary molecular sieve drying tower, a tertiary molecular sieve drying tower, a nitrogen heater and a nitrogen cooler, the compression unit comprises a compressor, and the distillation unit comprises a reboiler, a distillation tower, a tower top cooler, a pressure reducing tank and a waste gas treatment device.

[0008] Furthermore, the preheater is connected to the primary sulfuric acid tower.

[0009] Furthermore, the primary sulfuric acid tower and the secondary sulfuric acid tower are connected in series, and the primary sulfuric acid tower and the secondary sulfuric acid tower are both provided with an air inlet at the bottom and an air outlet at the top;

[0010] The preheater is connected to the air inlet at the bottom of the primary sulfuric acid tower through a gas pipeline;

[0011] The gas outlet at the top of the primary sulfuric acid tower is connected to the gas inlet at the bottom of the secondary sulfuric acid tower through a gas pipeline.

[0012] Furthermore, a spray device is provided at the top of each of the primary sulfuric acid tower and the secondary sulfuric acid tower, and the spray device sprays sulfuric acid from top to bottom.

[0013] Furthermore, the first-stage sulfuric acid tower and the second-stage sulfuric acid tower are both provided with a liquid inlet at the top, and a circulating liquid inlet and a waste liquid inlet at the bottom;

[0014] The liquid inlet of the primary sulfuric acid tower is connected to the circulating liquid port of the primary sulfuric acid tower through a liquid pipeline, the waste liquid port of the primary sulfuric acid tower is connected to the waste sulfuric acid tank through a liquid pipeline, and the liquid inlet of the primary sulfuric acid tower is also connected to the waste liquid port of the secondary sulfuric acid tower through a liquid pipeline;

[0015] The liquid inlet of the secondary sulfuric acid tower is connected to the concentrated sulfuric acid tank and the circulating liquid port of the secondary sulfuric acid tower through a liquid pipeline, and the waste liquid port of the secondary sulfuric acid tower is also connected to the waste sulfuric acid tank through a liquid pipeline.

[0016] Furthermore, a circulating cooler is provided outside the primary sulfuric acid tower and the secondary sulfuric acid tower.

[0017] Furthermore, the waste sulfuric acid tank is also provided with a waste gas outlet, which is connected to the waste gas treatment device through a gas pipeline.

[0018] Furthermore, the demister is connected to the gas outlet of the secondary sulfuric acid tower through a gas pipeline.

[0019] Furthermore, the first-stage molecular sieve drying tower, the second-stage molecular sieve drying tower and the third-stage molecular sieve drying tower are all provided with a hydrogen chloride inlet and a hydrogen chloride outlet;

[0020] The demister is connected to the hydrogen chloride inlet of the first-stage molecular sieve drying tower, the second-stage molecular sieve drying tower and the third-stage molecular sieve drying tower respectively through a gas pipeline;

[0021] The compressor is connected to the hydrogen chloride outlets of the first-stage molecular sieve drying tower, the second-stage molecular sieve drying tower and the third-stage molecular sieve drying tower respectively through gas pipelines;

[0022] The hydrogen chloride inlet and hydrogen chloride outlet of the first-stage molecular sieve drying tower, the second-stage molecular sieve drying tower and the third-stage molecular sieve drying tower are respectively connected through gas pipelines, wherein valves are installed on the gas pipelines to control the opening and closing of the hydrogen chloride inlet and the hydrogen chloride outlet.

[0023] Furthermore, the lower parts of the first-stage molecular sieve drying tower, the second-stage molecular sieve drying tower and the third-stage molecular sieve drying tower are all provided with nitrogen inlets, and the upper parts are all provided with nitrogen outlets, wherein valves are installed on the gas pipelines to control the opening and closing of the nitrogen inlet and the nitrogen outlet, the nitrogen inlet is connected to the nitrogen heater, and the nitrogen outlet is connected to the nitrogen cooler.

[0024] Furthermore, the nitrogen cooler is connected to the exhaust gas treatment device through a gas pipeline.

[0025] Furthermore, the first-stage molecular sieve drying tower, the second-stage molecular sieve drying tower and the third-stage molecular sieve drying tower are connected in series or in parallel.

[0026] Furthermore, when the series connection is performed, the valves on the gas pipeline are controlled to keep the hydrogen chloride inlet and hydrogen chloride outlet of any two molecular sieve drying towers among the first-stage molecular sieve drying tower, the second-stage molecular sieve drying tower and the third-stage molecular sieve drying tower open, the nitrogen inlet and the nitrogen outlet closed, and the hydrogen chloride inlet and hydrogen chloride outlet of the remaining molecular sieve drying tower closed, and the nitrogen inlet and nitrogen outlet opened;

[0027] At this time, the hydrogen chloride inlet of one of the any two molecular sieve drying towers is connected to the demister, the hydrogen chloride outlet is connected to the hydrogen chloride inlet of the other of the any two molecular sieve drying towers, and the hydrogen chloride outlet of the other of the any two molecular sieve drying towers is connected to the compressor;

[0028] The nitrogen inlet of the remaining molecular sieve drying tower is connected to the nitrogen heater, and the nitrogen outlet is connected to the nitrogen cooler.

[0029] Furthermore, when connected in parallel, the valves on the gas pipeline are controlled to keep the hydrogen chloride inlet and hydrogen chloride outlet of any two molecular sieve drying towers among the first-stage molecular sieve drying tower, the second-stage molecular sieve drying tower and the third-stage molecular sieve drying tower open, the nitrogen inlet and the nitrogen outlet closed, and the hydrogen chloride inlet and hydrogen chloride outlet of the remaining molecular sieve drying tower closed, and the nitrogen inlet and the nitrogen outlet opened;

[0030] At this time, the hydrogen chloride inlets of any two molecular sieve drying towers are connected to the demister at the same time, and the hydrogen chloride outlets are connected to the compressor at the same time;

[0031] The nitrogen inlet of the remaining molecular sieve drying tower is connected to the nitrogen heater, and the nitrogen outlet is connected to the nitrogen cooler.

[0032] Furthermore, a hydrogen chloride molecular sieve layer is provided in the first-stage molecular sieve drying tower, the second-stage molecular sieve drying tower and the third-stage molecular sieve drying tower.

[0033] Furthermore, a circulating cooler is arranged outside the compressor.

[0034] Furthermore, the compressor is also provided with an exhaust gas port, and the exhaust gas port is connected to the exhaust gas treatment device through a gas pipeline.

[0035] Furthermore, the compressor is connected to the distillation tower through a liquid pipeline, the liquid outlet at the bottom of the distillation tower is connected to the pressure reducing tank, and the reboiler is arranged on the outside of the bottom of the distillation tower and is connected to the distillation tower through a flange.

[0036] Furthermore, the distillation tower is provided with a gas outlet at the top and a liquid outlet at the bottom.

[0037] Furthermore, the tower top cooler is connected to the gas outlet at the top of the distillation tower through a gas pipeline.

[0038] Furthermore, the tower top cooler is also connected to the exhaust gas treatment device through a gas pipeline.

[0039] Beneficial effects of the utility model:

[0040] 1. The utility model sets a sulfuric acid drying tower and a molecular sieve drying tower in the drying unit, and removes the moisture in the wet hydrogen chloride gas by a two-step drying method, reducing the moisture content in the wet hydrogen chloride gas to ≤10ppm, and further rectifying the volume percentage of the hydrogen chloride gas to ≥99.5%, so that the hydrogen chloride gas meets the industrial use requirements, and the drying and dehydration process is simple and easy. First, the wet hydrogen chloride gas is dried by the sulfuric acid drying tower to remove most of the water in the wet hydrogen chloride gas, and then the dried wet hydrogen chloride gas is passed through the molecular sieve drying tower to continue to remove the remaining moisture in the hydrogen chloride, so as to meet the use standard;

[0041] 2. In the molecular sieve drying process of the utility model, a hydrogen chloride molecular sieve layer is arranged in the molecular sieve drying tower for dehydration, wherein the hydrogen chloride molecular sieve layer is resistant to acid corrosion, and compared with the traditional molecular sieve dryer, it has excellent dehydration performance and corrosion resistance, and can effectively reduce the water content in the wet hydrogen chloride gas. In addition, the cost of the dehydration equipment and process in the utility model is low, and compared with the preparation of electronic grade hydrogen chloride, the cost of the utility model is greatly reduced;

[0042] 3. In the utility model, after the hydrogen chloride is dehydrated, it further enters the distillation tower, and the low-boiling point gas in the wet hydrogen chloride gas is removed by utilizing the different boiling points of the substances, and finally high-purity hydrogen chloride with a purity of ≥99.5% is obtained. The system of the utility model for purifying high-purity hydrogen chloride gas has a simple and easy purification process and is suitable for large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a device diagram of a purification system for high-purity hydrogen chloride in the utility model.

[0044] The names of the numbers in the figure are: A. drying unit, B. compression unit, C. distillation unit, 1. preheater, 2. primary sulfuric acid tower, 3. secondary sulfuric acid tower, 4. concentrated sulfuric acid tank, 5. waste sulfuric acid tank, 6. demister, 7. primary molecular sieve drying tower, 8. secondary molecular sieve drying tower, 9. tertiary molecular sieve drying tower, 10. nitrogen heater, 11. nitrogen cooler, 12. compressor, 13. reboiler, 14. distillation tower, 15. top cooler, 16. pressure reducing tank, 17. waste gas treatment device. DETAILED DESCRIPTION

[0045] The invention is described in detail below with reference to the embodiments:

[0046] The invention provides a high-purity hydrogen chloride purification system, which can remove moisture and other impurity gases in wet hydrogen chloride gas, has a simple and convenient purification process, greatly improves the purity of hydrogen chloride gas, and reduces the cost of industrial production.

[0047] Example 1

[0048] The utility model provides a purification system for high-purity hydrogen chloride. According to the flow direction of wet hydrogen chloride gas, the purification system comprises a drying unit A, a compression unit B and a distillation unit C, wherein the drying unit A comprises a preheater 1, a primary sulfuric acid tower 2, a secondary sulfuric acid tower 3, a concentrated sulfuric acid tank 4, a waste sulfuric acid tank 5, a demister 6, a primary molecular sieve drying tower 7, a secondary molecular sieve drying tower 8, a tertiary molecular sieve drying tower 9, a nitrogen heater 10 and a nitrogen cooler 11, the compression unit B comprises a compressor 12, and the distillation unit C comprises a reboiler 13, a distillation tower 14, a tower top cooler 15, a pressure reducing tank 16 and a waste gas treatment device 17.

[0049] The preheater 1 described in the utility model is connected with the primary sulfuric acid tower 2, the primary sulfuric acid tower 2 and the secondary sulfuric acid tower 3 are connected in series, the primary sulfuric acid tower 2 and the secondary sulfuric acid tower 3 are both provided with an air inlet at the bottom, and an air outlet at the top, the preheater 1 is connected with the air inlet at the bottom of the primary sulfuric acid tower 2 through a gas pipeline, the air outlet at the top of the primary sulfuric acid tower 2 is connected with the air inlet at the bottom of the secondary sulfuric acid tower 3 through a gas pipeline, the preheater 1 is connected with the air inlet at the bottom of the primary sulfuric acid tower 2 through a gas pipeline, the air outlet at the top of the primary sulfuric acid tower 2 is connected with the air inlet at the bottom of the secondary sulfuric acid tower 3 through a gas pipeline, the primary sulfuric acid tower 2 and the secondary sulfuric acid tower 3 are both provided with a liquid inlet at the top, and a circulating liquid port and a waste liquid port are provided at the bottom, the The liquid inlet of the primary sulfuric acid tower 2 is connected to the circulating liquid port of the primary sulfuric acid tower 2 through a liquid pipeline, the waste liquid port of the primary sulfuric acid tower 2 is connected to the waste sulfuric acid tank 5 through a liquid pipeline, the liquid inlet of the primary sulfuric acid tower 2 is also connected to the waste liquid port of the secondary sulfuric acid tower 3 through a liquid pipeline, the liquid inlet of the secondary sulfuric acid tower 3 is connected to the concentrated sulfuric acid tank 4 and the circulating liquid port of the secondary sulfuric acid tower 3 through a liquid pipeline, the waste liquid port of the secondary sulfuric acid tower 3 is also connected to the waste sulfuric acid tank 5 through a liquid pipeline, the primary sulfuric acid tower 2 and the secondary sulfuric acid tower 3 are externally provided with a circulating cooler, the waste sulfuric acid tank 5 is also provided with a waste gas port, which is connected to the waste gas treatment device 17 through a gas pipeline, and the demister 6 is connected to the gas outlet of the secondary sulfuric acid tower 3 through a gas pipeline;

[0050] The first-stage molecular sieve drying tower 7, the second-stage molecular sieve drying tower 8 and the third-stage molecular sieve drying tower 9 are all provided with a hydrogen chloride inlet and a hydrogen chloride outlet. The demister 6 is connected to the hydrogen chloride inlets of the first-stage molecular sieve drying tower 7, the second-stage molecular sieve drying tower 8 and the third-stage molecular sieve drying tower 9 through a gas pipeline, and the compressor 12 is connected to the hydrogen chloride outlets of the first-stage molecular sieve drying tower 7, the second-stage molecular sieve drying tower 8 and the third-stage molecular sieve drying tower 9 through a gas pipeline. The hydrogen chloride inlets and hydrogen chloride outlets of the first-stage molecular sieve drying tower 7, the second-stage molecular sieve drying tower 8 and the third-stage molecular sieve drying tower 9 are respectively connected through a gas pipeline, wherein valves are installed on the gas pipeline to control the opening and closing of the hydrogen chloride inlet and the hydrogen chloride outlet. The first-stage molecular sieve drying tower 7, the second-stage molecular sieve drying tower 8 and the third-stage molecular sieve drying tower 9 are all provided with nitrogen inlets at the bottom and nitrogen outlets at the top, wherein valves are installed on the gas pipelines to control the opening and closing of the nitrogen inlet and the nitrogen outlet, the nitrogen inlet is connected to the nitrogen heater 10, the nitrogen outlet is connected to the nitrogen cooler 11, the nitrogen cooler 11 is connected to the exhaust gas treatment device 17 through a gas pipeline, the first-stage molecular sieve drying tower 7, the second-stage molecular sieve drying tower 8 and the third-stage molecular sieve drying tower 9 are connected in series and in parallel. When connected in series, the valves on the gas pipeline are controlled to keep the first-stage molecular sieve drying tower 7, the second-stage molecular sieve drying tower 8 and the third-stage molecular sieve drying tower 9 connected in series. The hydrogen chloride inlet and hydrogen chloride outlet of any two molecular sieve drying towers in the sieve drying tower 9 are opened, the nitrogen inlet and nitrogen outlet are closed, the hydrogen chloride inlet and hydrogen chloride outlet of the remaining molecular sieve drying tower are closed, and the nitrogen inlet and nitrogen outlet are opened. At this time, the hydrogen chloride inlet of one molecular sieve drying tower in the any two molecular sieve drying towers is connected to the demister 6, the hydrogen chloride outlet is connected to the hydrogen chloride inlet of the other molecular sieve drying tower in the any two molecular sieve drying towers, the hydrogen chloride outlet of the other molecular sieve drying tower in the any two molecular sieve drying towers is connected to the compressor 12, and the nitrogen inlet of the remaining molecular sieve drying tower is connected to the nitrogen heater 10, and the nitrogen outlet is connected to the nitrogen cooler 1 1, the first-stage molecular sieve drying tower 7, the second-stage molecular sieve drying tower 8, and the third-stage molecular sieve drying tower 9 are all provided with a hydrogen chloride molecular sieve layer, the compressor 12 is also provided with a circulating cooler, the compressor 12 is also provided with a waste gas port, the waste gas port is connected to the waste gas treatment device 17 through a gas pipeline, the compressor 12 is connected to the distillation tower 14 through a liquid pipeline, the distillation tower 14 is provided with a gas outlet at the top and a liquid outlet at the bottom, the tower top cooler 15 is connected to the gas outlet at the top of the distillation tower 14 through a gas pipeline, the reboiler 13 is provided on the outside of the bottom of the distillation tower 14, and is connected to the distillation tower 14 through a flange, and the tower top cooler 15 is also connected to the waste gas treatment device 17 through a gas pipeline,A liquid outlet is provided at the bottom of the reboiler 13 at the bottom of the distillation tower 14, and the liquid outlet is connected to the pressure reducing tank 16.

[0051] In the utility model, the wet hydrogen chloride gas passes through the preheater 1 of the drying unit A, enters the primary sulfuric acid tower 2 from the air inlet at the bottom of the primary sulfuric acid tower 2, the top of the primary sulfuric acid tower 2 is equipped with a spraying device, spraying sulfuric acid from top to bottom to dry the wet hydrogen chloride gas, and the dried wet hydrogen chloride gas enters the secondary sulfuric acid tower 3 from the air outlet at the top of the primary sulfuric acid tower 2 through the air inlet at the bottom of the secondary sulfuric acid tower 3, the top of the secondary sulfuric acid tower 3 is equipped with a spraying device, spraying sulfuric acid from top to bottom to dry the wet hydrogen chloride gas, and then enters the demister 6 from the air outlet at the top of the secondary sulfuric acid tower 3 for demisting, the primary sulfuric acid tower 2 and the secondary sulfuric acid tower 3 are provided with sulfuric acid by the concentrated sulfuric acid tank 4, the sulfuric acid in the concentrated sulfuric acid tank 4 enters the secondary sulfuric acid tower 3 from the liquid inlet at the top of the secondary sulfuric acid tower 3, and then The gas is returned to the secondary sulfuric acid tower 3 through the circulating liquid port at the bottom of the secondary sulfuric acid tower 3 for further use, and finally enters the liquid inlet at the top of the primary sulfuric acid tower 2 or is discharged into the waste sulfuric acid tank 5 through the waste liquid port at the bottom of the secondary sulfuric acid tower 3, and the wet hydrogen chloride gas in the primary sulfuric acid tower 2 is continued to be dried, and then returns to the liquid inlet of the primary sulfuric acid tower 2 through the circulating liquid port at the bottom of the primary sulfuric acid tower 2 for further drying, and finally is discharged into the waste sulfuric acid tank 5 through the waste liquid port at the bottom of the primary sulfuric acid tower 2, wherein the waste sulfuric acid tank 5 is also provided with a waste gas port, which is connected to the waste gas treatment device 17, and the gas in the waste sulfuric acid tank 5 enters the waste gas treatment device 17 for treatment, and the primary sulfuric acid tower 2 and the secondary sulfuric acid tower 3 release heat during the drying process, and are cooled by the circulating coolers outside the primary sulfuric acid tower 2 and the secondary sulfuric acid tower 3;

[0052] The dried wet hydrogen chloride gas has a water content of less than 50 ppm after being defogged by the demister 6, and then enters the hydrogen chloride inlet at the top of the primary molecular sieve drying tower 7 in sequence, and then enters the hydrogen chloride inlet of the secondary molecular sieve drying tower 8 from the hydrogen chloride outlet at the bottom of the primary molecular sieve drying tower 7 for dehydration. The water content of the dehydrated hydrogen chloride gas is less than 10 ppm. Finally, the dehydrated hydrogen chloride gas enters the compressor 12 in the compression unit B from the hydrogen chloride outlet of the secondary molecular sieve drying tower 8, and the dehydrated hydrogen chloride is compressed to obtain liquid hydrogen chloride. After the primary molecular sieve drying tower 7 or the secondary molecular sieve drying tower 8 or the tertiary molecular sieve drying tower 9 is used, the nitrogen is heated by the nitrogen heater 10 and then passed into the primary molecular sieve drying tower 7 or the secondary molecular sieve drying tower 8 or the tertiary molecular sieve drying tower 9 to regenerate the hydrogen chloride molecular sieve layer therein, and the regenerated nitrogen enters the exhaust gas treatment device 17 through the nitrogen cooler 11 for treatment. In addition, the compressor 12 is externally equipped with a cooler to cool the compressor 12, and the exhaust gas in the compressor 12 enters the exhaust gas treatment device 17 for treatment;

[0053] The liquid hydrogen chloride enters the distillation tower 14 in the distillation unit C, and is boiled by the reboiler 13 at the bottom of the distillation tower 14, wherein the low-boiling-point hydrogen gas enters the top of the distillation tower 14 upward, and enters the exhaust gas treatment device 17 through the tower top cooler 15 for post-treatment, and the rectified liquid hydrogen chloride enters the pressure reduction tank 16 through the liquid outlet at the bottom of the distillation tower 14 to obtain high-purity hydrogen chloride.

[0054] In the utility model, the high-purity hydrogen chloride comprises hydrogen chloride, hydrogen, nitrogen, carbon dioxide, and water, wherein the volume percentage of hydrogen chloride is 99.5 vol%, the volume percentage of hydrogen, nitrogen, and carbon dioxide is 0.499%, and the water content is 10 ppm;

[0055] The wet hydrochloric acid gas comprises hydrochloric acid, hydrogen, nitrogen, carbon dioxide and water, wherein the volume percentage of hydrochloric acid is 93 vol%, and the volume percentage of hydrogen, nitrogen, carbon dioxide and water is 7 vol%;

[0056] The mass fraction of sulfuric acid in the secondary sulfuric acid drying tower 3 is 98wt% and the transparency is 160;

[0057] The shape of the hydrogen chloride molecular sieve in the hydrogen chloride molecular sieve layer is spherical, with a diameter of 3 mm, a static water adsorption rate of 21%, an abrasion rate of 0.25%, a bulk density of 0.75 g / mL, a particle size of 98%, a crushing force of 100 N / particle, a crushing force variation coefficient of 0.3, a dynamic water adsorption rate of 20%, a packaged product moisture content of 1.5%, and a static ethylene adsorption of 3 mg / g;

[0058] Circulating cooling water is passed through the circulating cooler outside the primary sulfuric acid tower 2, the secondary sulfuric acid tower 3 and the compressor 12. The feed water temperature of the circulating cooling water is 28°C, the return water temperature is 38°C, the feed water pressure is 0.4MPag, and the return water pressure is 0.2MPag;

[0059] The preheating temperature of the preheater is 15°C;

[0060] The output of the waste sulfuric acid liquid in the waste sulfuric acid tank 5 is 8 kg / t of hydrogen chloride.

[0061] Example 2

[0062] The utility model provides a purification system for high-purity hydrogen chloride. According to the flow direction of wet hydrogen chloride gas, the purification system comprises a drying unit A, a compression unit B and a distillation unit C, wherein the drying unit A comprises a preheater 1, a primary sulfuric acid tower 2, a secondary sulfuric acid tower 3, a concentrated sulfuric acid tank 4, a waste sulfuric acid tank 5, a demister 6, a primary molecular sieve drying tower 7, a secondary molecular sieve drying tower 8, a tertiary molecular sieve drying tower 9, a nitrogen heater 10 and a nitrogen cooler 11, the compression unit B comprises a compressor 12, and the distillation unit C comprises a reboiler 13, a distillation tower 14, a tower top cooler 15, a pressure reducing tank 16 and a waste gas treatment device 17.

[0063] The preheater 1 described in the utility model is connected with the primary sulfuric acid tower 2, the primary sulfuric acid tower 2 and the secondary sulfuric acid tower 3 are connected in series, the primary sulfuric acid tower 2 and the secondary sulfuric acid tower 3 are both provided with an air inlet at the bottom, and an air outlet at the top, the preheater 1 is connected with the air inlet at the bottom of the primary sulfuric acid tower 2 through a gas pipeline, the air outlet at the top of the primary sulfuric acid tower 2 is connected with the air inlet at the bottom of the secondary sulfuric acid tower 3 through a gas pipeline, the preheater 1 is connected with the air inlet at the bottom of the primary sulfuric acid tower 2 through a gas pipeline, the air outlet at the top of the primary sulfuric acid tower 2 is connected with the air inlet at the bottom of the secondary sulfuric acid tower 3 through a gas pipeline, the primary sulfuric acid tower 2 and the secondary sulfuric acid tower 3 are both provided with a liquid inlet at the top, and a circulating liquid port and a waste liquid port are provided at the bottom, the The liquid inlet of the primary sulfuric acid tower 2 is connected to the circulating liquid port of the primary sulfuric acid tower 2 through a liquid pipeline, the waste liquid port of the primary sulfuric acid tower 2 is connected to the waste sulfuric acid tank 5 through a liquid pipeline, the liquid inlet of the primary sulfuric acid tower 2 is also connected to the waste liquid port of the secondary sulfuric acid tower 3 through a liquid pipeline, the liquid inlet of the secondary sulfuric acid tower 3 is connected to the concentrated sulfuric acid tank 4 and the circulating liquid port of the secondary sulfuric acid tower 3 through a liquid pipeline, the waste liquid port of the secondary sulfuric acid tower 3 is also connected to the waste sulfuric acid tank 5 through a liquid pipeline, the primary sulfuric acid tower 2 and the secondary sulfuric acid tower 3 are externally provided with a circulating cooler, the waste sulfuric acid tank 5 is also provided with a waste gas port, which is connected to the waste gas treatment device 17 through a gas pipeline, and the demister 6 is connected to the gas outlet of the secondary sulfuric acid tower 3 through a gas pipeline;

[0064] The first-stage molecular sieve drying tower 7, the second-stage molecular sieve drying tower 8 and the third-stage molecular sieve drying tower 9 are all provided with a hydrogen chloride inlet and a hydrogen chloride outlet. The demister 6 is connected to the hydrogen chloride inlets of the first-stage molecular sieve drying tower 7, the second-stage molecular sieve drying tower 8 and the third-stage molecular sieve drying tower 9 through a gas pipeline, and the compressor 12 is connected to the hydrogen chloride outlets of the first-stage molecular sieve drying tower 7, the second-stage molecular sieve drying tower 8 and the third-stage molecular sieve drying tower 9 through a gas pipeline. The hydrogen chloride inlets and hydrogen chloride outlets of the first-stage molecular sieve drying tower 7, the second-stage molecular sieve drying tower 8 and the third-stage molecular sieve drying tower 9 are respectively connected through a gas pipeline, wherein valves are installed on the gas pipelines to control the hydrogen chloride inlet and the hydrogen chloride outlet. The opening and closing of the hydrogen outlet, the lower part of the first-stage molecular sieve drying tower 7, the second-stage molecular sieve drying tower 8 and the third-stage molecular sieve drying tower 9 are also provided with a nitrogen inlet, and the upper part is also provided with a nitrogen outlet, wherein the gas pipeline is equipped with a valve to control the opening and closing of the nitrogen inlet and the nitrogen outlet, the nitrogen inlet is connected to the nitrogen heater 10, the nitrogen outlet is connected to the nitrogen cooler 11, the nitrogen cooler 11 is connected to the exhaust gas treatment device 17 through a gas pipeline, the first-stage molecular sieve drying tower 7, the second-stage molecular sieve drying tower 8 and the third-stage molecular sieve drying tower 9 have two connection modes: series connection and parallel connection. When connected in parallel, the valve on the gas pipeline is controlled to keep the first-stage molecular sieve drying tower 7 The hydrogen chloride inlet and hydrogen chloride outlet of any two molecular sieve drying towers in the secondary molecular sieve drying tower 8 and the tertiary molecular sieve drying tower 9 are opened, and the nitrogen inlet and nitrogen outlet are closed. The hydrogen chloride inlet and hydrogen chloride outlet of the remaining molecular sieve drying tower are closed, and the nitrogen inlet and nitrogen outlet are opened. At this time, the hydrogen chloride inlets of any two molecular sieve drying towers are connected to the demister 6 at the same time, and the hydrogen chloride outlet is connected to the compressor 12 at the same time, while the nitrogen inlet of the remaining molecular sieve drying tower is connected to the nitrogen heater 10, and the nitrogen outlet is connected to the nitrogen cooler 11. The primary molecular sieve drying tower 7, the secondary molecular sieve drying tower 8, and the tertiary molecular sieve drying tower 9 are all provided with hydrogen chloride molecular sieve layers. A circulating cooler is also provided outside the compressor 12. The compressor 12 is also provided with a waste gas port, and the waste gas port is connected to the waste gas treatment device 17 through a gas pipeline. The compressor 12 is connected to the distillation tower 14 through a liquid pipeline. The distillation tower 14 is provided with a gas outlet at the top and a liquid outlet at the bottom. The top cooler 15 is connected to the gas outlet at the top of the distillation tower 14 through a gas pipeline. The reboiler 13 is provided on the outside of the bottom of the distillation tower 14 and is connected to the distillation tower 14 through a flange. The top cooler 15 is also connected to the waste gas treatment device 17 through a gas pipeline. The bottom of the reboiler 13 at the bottom of the distillation tower 14 is provided with a liquid outlet, and the liquid outlet is connected to the pressure reducing tank 16.

[0065] In the utility model, the wet hydrogen chloride gas passes through the preheater 1 of the drying unit A, enters the primary sulfuric acid tower 2 from the air inlet at the bottom of the primary sulfuric acid tower 2, the top of the primary sulfuric acid tower 2 is equipped with a spraying device, spraying sulfuric acid from top to bottom to dry the wet hydrogen chloride gas, and the dried wet hydrogen chloride gas enters the secondary sulfuric acid tower 3 from the air outlet at the top of the primary sulfuric acid tower 2 through the air inlet at the bottom of the secondary sulfuric acid tower 3, the top of the secondary sulfuric acid tower 3 is equipped with a spraying device, spraying sulfuric acid from top to bottom to dry the wet hydrogen chloride gas, and then enters the demister 6 from the air outlet at the top of the secondary sulfuric acid tower 3 for demisting, the primary sulfuric acid tower 2 and the secondary sulfuric acid tower 3 are provided with sulfuric acid by the concentrated sulfuric acid tank 4, the sulfuric acid in the concentrated sulfuric acid tank 4 enters the secondary sulfuric acid tower 3 from the liquid inlet at the top of the secondary sulfuric acid tower 3, and then The gas is returned to the secondary sulfuric acid tower 3 through the circulating liquid port at the bottom of the secondary sulfuric acid tower 3 for further use, and finally enters the liquid inlet at the top of the primary sulfuric acid tower 2 or is discharged into the waste sulfuric acid tank 5 through the waste liquid port at the bottom of the secondary sulfuric acid tower 3, and the wet hydrogen chloride gas in the primary sulfuric acid tower 2 is continued to be dried, and then returns to the liquid inlet of the primary sulfuric acid tower 2 through the circulating liquid port at the bottom of the primary sulfuric acid tower 2 for further drying, and finally is discharged into the waste sulfuric acid tank 5 through the waste liquid port at the bottom of the primary sulfuric acid tower 2, wherein the waste sulfuric acid tank 5 is also provided with a waste gas port, which is connected to the waste gas treatment device 17, and the gas in the waste sulfuric acid tank 5 enters the waste gas treatment device 17 for treatment, and the primary sulfuric acid tower 2 and the secondary sulfuric acid tower 3 release heat during the drying process, and are cooled by the circulating coolers outside the primary sulfuric acid tower 2 and the secondary sulfuric acid tower 3;

[0066] The dried wet hydrogen chloride gas has a water content of less than 50 ppm after being defogged by the demister 6, and then enters the hydrogen chloride inlet at the top of the primary molecular sieve drying tower 7 and the secondary molecular sieve drying tower 8 for dehydration. The water content of the dehydrated hydrogen chloride gas is less than 10 ppm. Finally, it enters the compressor 12 in the compression unit B through the hydrogen chloride outlets of the primary molecular sieve drying tower 7 and the secondary molecular sieve drying tower 8, and the dehydrated hydrogen chloride is compressed to obtain liquid hydrogen chloride. After the primary molecular sieve drying tower 7, the secondary molecular sieve drying tower 8 or the tertiary molecular sieve drying tower 9 is used, the nitrogen heater 10 heats the nitrogen and then passes it into the primary molecular sieve drying tower 7, the secondary molecular sieve drying tower 8 or the tertiary molecular sieve drying tower 9 to regenerate the hydrogen chloride molecular sieve layer therein. The regenerated nitrogen enters the exhaust gas treatment device 17 through the nitrogen cooler 11 for treatment. In addition, the compressor 12 is equipped with a cooler to cool the compressor 12, and the exhaust gas in the compressor 12 enters the exhaust gas absorption device 17 for treatment;

[0067] The liquid hydrogen chloride enters the distillation tower 14 in the distillation unit C, and is boiled by the reboiler 13 at the bottom of the distillation tower 14, wherein the low-boiling-point hydrogen gas enters the top of the distillation tower 14 upward, and enters the exhaust gas treatment device 17 through the tower top cooler 15 for post-treatment, and the rectified liquid hydrogen chloride enters the pressure reduction tank 16 through the liquid outlet at the bottom of the distillation tower 14 to obtain high-purity hydrogen chloride.

[0068] In the utility model, the high-purity hydrogen chloride comprises hydrogen chloride, hydrogen, nitrogen, carbon dioxide, and water, wherein the volume percentage of hydrogen chloride is 99.5 vol%, the volume percentage of hydrogen, nitrogen, and carbon dioxide is 0.499%, and the water content is 10 ppm;

[0069] The wet hydrochloric acid gas comprises hydrochloric acid, hydrogen, nitrogen, carbon dioxide and water, wherein the volume percentage of hydrochloric acid is 93 vol%, and the volume percentage of hydrogen, nitrogen, carbon dioxide and water is 7 vol%;

[0070] The mass fraction of sulfuric acid in the secondary sulfuric acid drying tower 3 is 98wt% and the transparency is 160;

[0071] The shape of the hydrogen chloride molecular sieve in the hydrogen chloride molecular sieve layer is spherical, with a diameter of 3-5 mm, a static water adsorption rate of 21%, an abrasion rate of 0.25%, a bulk density of 0.75 g / mL, a particle size of 98%, a crushing resistance of 100 N / particle, a crushing resistance coefficient of variation of 0.3, a dynamic water adsorption rate of 20%, a packaged product moisture content of 1.5%, and a static ethylene adsorption of 3 mg / g;

[0072] Circulating cooling water is passed through the circulating cooler outside the primary sulfuric acid tower 2, the secondary sulfuric acid tower 3 and the compressor 12. The feed water temperature of the circulating cooling water is 28°C, the return water temperature is 38°C, the feed water pressure is 0.4MPag, and the return water pressure is 0.2MPag;

[0073] The preheating temperature of the preheater is 20°C;

[0074] The output of the waste sulfuric acid liquid in the waste sulfuric acid tank 5 is 8 kg / t of hydrogen chloride.

[0075] Based on the above, it can be seen that the high-purity hydrogen chloride purification system described in this patent has a wide range of applications, low cost, and extremely high market prospects.

[0076] The above description is only a preferred embodiment of the present invention and does not constitute any other form of limitation to the present invention. Any modification or equivalent change made based on the technical essence of the present invention still falls within the scope of protection required by the present invention.

Claims

1. A high-purity hydrogen chloride purification system, characterized in that: According to the flow direction of the wet hydrogen chloride gas, the purification system comprises a drying unit (A), a compression unit (B) and a distillation unit (C), wherein the drying unit (A) comprises a preheater (1), a primary sulfuric acid tower (2), a secondary sulfuric acid tower (3), a concentrated sulfuric acid tank (4), a waste sulfuric acid tank (5), a demister (6), a primary molecular sieve drying tower (7), a secondary molecular sieve drying tower (8), a tertiary molecular sieve drying tower (9), a nitrogen heater (10) and a nitrogen cooler (11), the compression unit (B) comprises a compressor (12), and the distillation unit (C) comprises a reboiler (13), a distillation tower (14), a tower top cooler (15), a pressure reducing tank (16) and a waste gas treatment device (17).

2. The purification system of high-purity hydrogen chloride according to claim 1, characterized in that: The tops of the primary sulfuric acid tower (2) and the secondary sulfuric acid tower (3) are both provided with spraying devices, and the spraying devices spray sulfuric acid from top to bottom.

3. The purification system of high-purity hydrogen chloride according to claim 1, characterized in that: The first-stage sulfuric acid tower (2) and the second-stage sulfuric acid tower (3) are both provided with a liquid inlet at the top and a circulating liquid inlet and a waste liquid inlet at the bottom; The liquid inlet of the primary sulfuric acid tower (2) is connected to the circulating liquid outlet of the primary sulfuric acid tower (2) via a liquid pipeline, the waste liquid outlet of the primary sulfuric acid tower (2) is connected to the waste sulfuric acid tank (5) via a liquid pipeline, and the liquid inlet of the primary sulfuric acid tower (2) is also connected to the waste liquid outlet of the secondary sulfuric acid tower (3) via a liquid pipeline; The liquid inlet of the secondary sulfuric acid tower (3) is connected to the concentrated sulfuric acid tank (4) and the circulating liquid outlet of the secondary sulfuric acid tower (3) through a liquid pipeline, and the waste liquid outlet of the secondary sulfuric acid tower (3) is also connected to the waste sulfuric acid tank (5) through a liquid pipeline.

4. The purification system of high-purity hydrogen chloride according to claim 1, characterized in that: The first-stage molecular sieve drying tower (7), the second-stage molecular sieve drying tower (8) and the third-stage molecular sieve drying tower (9) are all provided with a hydrogen chloride inlet and a hydrogen chloride outlet; The demister (6) is connected to the hydrogen chloride inlet of the first-stage molecular sieve drying tower (7), the second-stage molecular sieve drying tower (8) and the third-stage molecular sieve drying tower (9) respectively through gas pipelines; The compressor (12) is connected to the hydrogen chloride outlets of the first-stage molecular sieve drying tower (7), the second-stage molecular sieve drying tower (8) and the third-stage molecular sieve drying tower (9) respectively through gas pipelines; The hydrogen chloride inlet and hydrogen chloride outlet of the first-stage molecular sieve drying tower (7), the second-stage molecular sieve drying tower (8) and the third-stage molecular sieve drying tower (9) are respectively connected via gas pipelines, wherein the gas pipelines are equipped with valves to control the opening and closing of the hydrogen chloride inlet and the hydrogen chloride outlet.

5. The purification system of high-purity hydrogen chloride according to claim 1, characterized in that: The first-stage molecular sieve drying tower (7), the second-stage molecular sieve drying tower (8) and the third-stage molecular sieve drying tower (9) are all provided with a nitrogen inlet at the bottom and a nitrogen outlet at the top, wherein valves are installed on the gas pipelines to control the opening and closing of the nitrogen inlet and the nitrogen outlet, the nitrogen inlet is connected to the nitrogen heater (10), and the nitrogen outlet is connected to the nitrogen cooler (11).

6. The high-purity hydrogen chloride purification system according to claim 1, characterized in that: The first-stage molecular sieve drying tower (7), the second-stage molecular sieve drying tower (8) and the third-stage molecular sieve drying tower (9) are connected in series or in parallel.

7. The high-purity hydrogen chloride purification system according to claim 6, characterized in that: When the molecular sieve drying tower is connected in series, the valves on the gas pipeline are controlled to keep the hydrogen chloride inlet and hydrogen chloride outlet of any two molecular sieve drying towers among the first molecular sieve drying tower (7), the second molecular sieve drying tower (8) and the third molecular sieve drying tower (9) open, and the nitrogen inlet and nitrogen outlet closed; and the hydrogen chloride inlet and hydrogen chloride outlet of the remaining molecular sieve drying tower are closed, and the nitrogen inlet and nitrogen outlet are opened; At this time, the hydrogen chloride inlet of one of the two molecular sieve drying towers is connected to the demister (6), the hydrogen chloride outlet is connected to the hydrogen chloride inlet of the other molecular sieve drying tower of the two molecular sieve drying towers, and the hydrogen chloride outlet of the other molecular sieve drying tower of the two molecular sieve drying towers is connected to the compressor (12); The nitrogen inlet of the remaining molecular sieve drying tower is connected to the nitrogen heater (10), and the nitrogen outlet is connected to the nitrogen cooler (11).

8. The high-purity hydrogen chloride purification system according to claim 6, characterized in that: When connected in parallel, control the valves on the gas pipeline to keep the hydrogen chloride inlet and hydrogen chloride outlet of any two of the first-stage molecular sieve drying tower (7), the second-stage molecular sieve drying tower (8) and the third-stage molecular sieve drying tower (9) open, and the nitrogen inlet and nitrogen outlet closed; and keep the hydrogen chloride inlet and hydrogen chloride outlet of the remaining molecular sieve drying tower closed, and the nitrogen inlet and nitrogen outlet open; At this time, the hydrogen chloride inlets of any two molecular sieve drying towers are connected to the demister (6) at the same time, and the hydrogen chloride outlets are connected to the compressor (12) at the same time; The nitrogen inlet of the remaining molecular sieve drying tower is connected to the nitrogen heater (10), and the nitrogen outlet is connected to the nitrogen cooler (11).

9. The high-purity hydrogen chloride purification system according to claim 1, characterized in that: The first-stage molecular sieve drying tower (7), the second-stage molecular sieve drying tower (8) and the third-stage molecular sieve drying tower (9) are all provided with a hydrogen chloride molecular sieve layer.

10. The high-purity hydrogen chloride purification system according to claim 1, characterized in that: The compressor (12) is connected to the distillation tower (14) via a liquid pipeline, the liquid outlet at the bottom of the distillation tower (14) is connected to the pressure reducing tank (16), and the reboiler (13) is arranged outside the bottom of the distillation tower (14) and is connected to the distillation tower (14) via a flange.

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