A method and system for producing electronic grade hydrogen chloride with co-production of chemical grade hydrogen chloride and industrial grade hydrogen chloride

Abstract

The present application relates to hydrogen chloride purification technical field, especially to a kind of production electronic grade hydrogen chloride and the method and system of byproduct chemical grade hydrogen chloride and industrial grade hydrogen chloride.It is formed green environmental protection's circular economy by optimizing process flow, using chlorobenzene tail gas as raw material to produce electronic hydrogen chloride and chemical grade hydrogen chloride and industrial grade hydrogen chloride, and equipment investment cost is low, process production cost is low, market prospect is broad.The production process of the present application has no three wastes discharge, and the recovery rate of chlorobenzene is improved by returning the recovered mother liquor to the chlorobenzene production system;The recovery rate of main products electronic hydrogen chloride, chemical grade hydrogen chloride and industrial grade hydrogen chloride reaches 52%;After hydrogen chloride containing light components is absorbed by water, byproduct hydrochloric acid can be obtained;The light components discharged are nitrogen, oxygen and carbon dioxide, which do not pollute the environment;Chlorobenzene tail gas can be fully recycled.

Description

Technical Field

[0001] This invention relates to the field of hydrogen chloride purification technology, and in particular to a method and system for producing electronic-grade hydrogen chloride and simultaneously producing chemical-grade and industrial-grade hydrogen chloride. Background Technology

[0002] Electronic hydrogen chloride (hereinafter referred to as electronic hydrogen chloride) is an important supporting material for integrated circuit manufacturing. Electronic hydrogen chloride can be used to clean oxides and impurities on semiconductor material surfaces, as an additive in epitaxial growth processes, and as a gas-phase transfer medium in processes such as chemical vapor deposition (CVD) for semiconductor material deposition, vapor phase polishing, and etching. Chemical-grade hydrogen chloride is mainly used in chemical synthesis, pharmaceuticals, metal processing, and laboratories. It can be used for the preparation of acidic solutions, metal surface treatment, the synthesis of pharmaceutical intermediates, and as a chemical reagent, catalyst, and reaction activator. Industrial-grade hydrogen chloride can be used as a raw material for the preparation of other chemical substances, such as chlorides, chloroprene rubber, and polyvinyl chloride; in the pharmaceutical industry, it is used to prepare certain drugs and pharmaceutical preparations; and in the metal processing industry, it is used for degreasing and rust removal during cold rolling and heat treatment of steel.

[0003] Currently, various methods for purifying electronic-grade hydrogen chloride through continuous distillation have been disclosed in existing technologies. For example, CN 110255501 A discloses a method for preparing high-purity electronic-grade hydrogen chloride, which utilizes the chlorination reaction of toluene and chlorine to produce chlorotoluene, while simultaneously generating hydrogen chloride gas as a byproduct. Using this byproduct as raw material, the raw material undergoes dehydration, liquefaction, distillation to remove light components, and distillation to remove heavy components, thereby obtaining high-purity electronic-grade hydrogen chloride. However, this method requires removing moisture from the chlorotoluene tail gas using molecular sieves, followed by distillation to remove other impurities. When the tail gas has a high water content, other impurities may be introduced due to the reaction of hydrogen chloride with the adsorbent, thus increasing the subsequent separation burden and making it difficult to control the content of particles and metal ions. CN 114634163 A discloses a production apparatus and method for manufacturing electronic-grade hydrogen chloride, which utilizes byproduct and recovered hydrogen chloride or synthetic hydrogen chloride as raw materials, uses activated carbon or silica gel to remove moisture from industrial tail gas, and supplements this with distillation and reaction to remove C2 and other impurities. However, this method has a significantly higher distillation separation burden.

[0004] It is evident that there is still room for improvement in the existing technology for preparing electronic-grade hydrogen chloride. Summary of the Invention

[0005] To address the aforementioned problems in the prior art, this invention provides a method and system for producing electronic-grade hydrogen chloride in conjunction with chemical-grade and industrial-grade hydrogen chloride. Without introducing a third medium, dehydration and impurity removal are achieved through distillation technology, enabling control over the purity and cleanliness of the electronic-grade product while ensuring uniform and stable performance indicators.

[0006] Based on this, the present invention has the following technical solution:

[0007] In a first aspect, the present invention provides a method for producing electronic-grade hydrogen chloride and simultaneously producing chemical-grade and industrial-grade hydrogen chloride, comprising:

[0008] The tail gas emitted from the industrial production of chlorobenzene is used as raw material and fed into a stripping tower. The gas extracted from the top of the stripping tower is compressed to obtain a first high-pressure gas.

[0009] The first high-pressure gas is introduced into the recovery tower, and the gas extracted from the top of the recovery tower is compressed to obtain the second high-pressure gas.

[0010] A portion of the second high-pressure gas is passed into the light-light gas removal tower, and the other portion of the second high-pressure gas is condensed to obtain industrial-grade hydrogen chloride product.

[0011] A portion of the liquid from the light-light removal tower is discharged and recovered as a chemical-grade hydrogen chloride product, while another portion of the liquid from the light-light removal tower is partially vaporized. The resulting vapor phase is used as the rising vapor phase in the bottom of the light-light removal tower, and the resulting liquid phase enters the refining tower for further refining. Electronic-grade hydrogen chloride product is collected from the top of the refining tower.

[0012] The exhaust gas consists of hydrogen chloride, chlorine, organic gases, nitrogen, oxygen, carbon dioxide, and water.

[0013] In this invention, electronic-grade hydrogen chloride refers to hydrogen chloride with a concentration of not less than 99.9999%; chemical-grade hydrogen chloride refers to hydrogen chloride with a concentration of not less than 99.9%; and industrial-grade hydrogen chloride refers to hydrogen chloride with a concentration of not less than 99%.

[0014] In this invention, the raw material originates from industrial tail gas emitted during the production of chlorobenzene. Its main components include two parts: volatile components of the mother liquor carried out from the reactor (including unreacted raw material chlorine, benzene, and the product chlorobenzene) and air leaked into the system. Utilizing chlorobenzene tail gas as a raw material to prepare high-value-added electronic-grade hydrogen chloride will be key to forming a green and environmentally friendly circular economy, thereby achieving emission reduction and high-value-added utilization of waste materials.

[0015] According to the method for producing electronic-grade hydrogen chloride and simultaneously producing chemical-grade and industrial-grade hydrogen chloride provided by the present invention, the tail gas composition, in terms of molar content, includes: HCl not less than 90%, Cl2 not more than 0.5%, organic gas content not more than 0.5%, and the content of other components less than 1%; preferably, the molar content of water in the tail gas is less than 1%, and the molar content of carbon dioxide in the tail gas is less than 0.06%.

[0016] According to the method for producing electronic-grade hydrogen chloride and simultaneously producing chemical-grade and industrial-grade hydrogen chloride provided by the present invention, the water content in the feed to the recovery tower is less than 0.001% by molar content.

[0017] According to the method for producing electronic-grade hydrogen chloride and simultaneously producing chemical-grade and industrial-grade hydrogen chloride provided by the present invention, the content of chlorine and organic gases in the feed of the light-removal tower is less than 0.00001% by molar content.

[0018] According to the method for producing electronic-grade hydrogen chloride and simultaneously producing chemical-grade and industrial-grade hydrogen chloride provided by the present invention, the carbon dioxide content in the feed to the purification tower is less than 0.00004% by molar content.

[0019] In this invention, the raw material chlorobenzene tail gas contains water and a high concentration of carbon dioxide. The aqueous hydrogen chloride gas can corrode the stainless steel tower equipment. Furthermore, the boiling point of carbon dioxide (at normal pressure -78.45℃) is very close to that of hydrogen chloride (at normal pressure -85℃), making them difficult to separate. Based on extensive research, this invention has found that by optimizing the operating conditions of the light-light product stripping tower in the process described herein, it is possible to separate carbon dioxide and hydrogen chloride, thereby ensuring that the carbon dioxide concentration in the electronic-grade product meets national standards. Regarding water removal, this invention controls the operating conditions of the stripping tower to remove water to an extremely low concentration, minimizing water corrosion of the equipment. This saves costs and also allows for control of the metal ion content in the product.

[0020] According to the method for producing electronic-grade hydrogen chloride and simultaneously producing chemical-grade and industrial-grade hydrogen chloride provided by the present invention, the operating conditions of the light-light-removal tower are controlled as follows: the tower top operating pressure is 3.9~4.5MPa, the tower top operating temperature is 15~30℃, and the reflux ratio is 8~12.

[0021] Specifically, the tower top operating pressure can be any value among 3.9MPa, 4.0MPa, 4.1MPa, 4.2MPa, 4.3MPa, 4.4MPa, and 4.5MPa, or a range of values ​​with any two of the above values ​​as endpoints; the tower top operating temperature can be any value among 15℃, 16℃, 17℃, 18℃, 19℃, 20℃, 21℃, 22℃, 23℃, 24℃, 25℃, 26℃, 27℃, 28℃, 29℃, and 30℃, or a range of values ​​with any two of the above values ​​as endpoints; the reflux ratio can be any value among 8, 9, 10, 11, and 12, or a range of values ​​with any two of the above values ​​as endpoints.

[0022] According to the method for producing electronic-grade hydrogen chloride and simultaneously producing chemical-grade and industrial-grade hydrogen chloride provided by the present invention, the feed pressure of the light-light-removal tower is 3.9~4.9 MPa, and the feed temperature is 15~30°C; the pressure of the bottom product of the light-light-removal tower is 3.9~4.9 MPa, and the temperature of the bottom product is 15~30°C; the pressure of the exhaust gas at the top of the light-light-removal tower is 3.9~4.9 MPa, and the temperature of the exhaust gas at the top of the tower is 15~30°C; the pressure of the reflux at the top of the light-light-removal tower is 3.9~4.9 MPa, and the temperature of the reflux at the top of the tower is 15~30°C.

[0023] According to the method for producing electronic-grade hydrogen chloride and simultaneously producing chemical-grade and industrial-grade hydrogen chloride provided by the present invention, the operating conditions of the stripping tower are controlled as follows: the operating pressure at the top of the tower is 0.1~0.5MPa, the operating temperature at the top of the tower is -90~-75℃, and the reflux ratio is 0.4~1.

[0024] Specifically, the tower top operating pressure can be any value among 0.1MPa, 0.2MPa, 0.3MPa, 0.4MPa, and 0.5MPa, or a range of values ​​with any two of the above values ​​as endpoints; the tower top operating temperature can be any value among -90℃, -89℃, -88℃, -87℃, -86℃, -85℃, -84℃, -83℃, -82℃, -81℃, -80℃, -79℃, -78℃, -77℃, -76℃, and -75℃, or a range of values ​​with any two of the above values ​​as endpoints; the reflux ratio can be any value among 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, and 1, or a range of values ​​with any two of the above values ​​as endpoints.

[0025] According to the method for producing electronic-grade hydrogen chloride and simultaneously producing chemical-grade and industrial-grade hydrogen chloride provided by the present invention, the pressure of the vapor phase feed to the stripping tower is 0.07~0.17 MPa, and the temperature of the vapor phase feed is 0~10℃; the pressure of the liquid discharged from the bottom of the stripping tower is 0.07~0.17 MPa, and the temperature of the liquid discharged from the bottom of the tower is 25~40℃; the pressure of the exhaust gas from the top of the stripping tower is 0.07~0.17 MPa, and the temperature of the exhaust gas from the top of the tower is -90~-75℃; the pressure of the reflux from the top of the stripping tower is 0.07~0.17 MPa, and the temperature of the reflux from the top of the tower is -90~-75℃.

[0026] According to the method for producing electronic-grade hydrogen chloride and simultaneously producing chemical-grade and industrial-grade hydrogen chloride provided by the present invention, the feed pressure of the recovery tower is 0.08~0.18 MPa, and the feed temperature is 35~55℃; the pressure of the bottom product of the recovery tower is 0.08~0.18 MPa, and the temperature of the bottom product is -35~-20℃; the exhaust pressure of the top product of the recovery tower is 0.08~0.18 MPa, and the exhaust temperature is -35~-20℃; the reflux pressure at the top of the recovery tower is 0.08~0.18 MPa, and the reflux temperature is -35~-20℃; the reflux ratio is 0.4~1.

[0027] According to the method for producing electronic-grade hydrogen chloride and simultaneously producing chemical-grade and industrial-grade hydrogen chloride provided by the present invention, the feed pressure of the purification tower is 3.9~4.9 MPa, and the feed temperature is 15~30°C; the pressure of the bottom product of the purification tower is 3.9~4.9 MPa, and the temperature of the bottom product is 15~30°C; the pressure of the exhaust gas at the top of the purification tower is 3.9~4.9 MPa, and the exhaust gas temperature is 15~30°C; the pressure of the reflux at the top of the purification tower is 3.9~4.9 MPa, and the reflux temperature is 15~30°C; the reflux ratio is 2~5.

[0028] The method for producing electronic-grade hydrogen chloride and simultaneously producing chemical-grade and industrial-grade hydrogen chloride according to the present invention includes:

[0029] The tail gas emitted from the industrial production of chlorobenzene is used as raw material and fed into the top of the stripping tower. The light components at the top of the stripping tower are compressed to obtain a first high-pressure gas.

[0030] The first high-pressure gas is introduced into the bottom of the recovery tower, and the bottom liquid of the recovery tower is throttled and expanded before flowing back to the stripping tower. The light components at the top of the recovery tower are compressed to obtain the second high-pressure gas.

[0031] A portion of the second high-pressure gas is passed into the light-weight gas removal tower, and the other portion of the second high-pressure gas is condensed to obtain a high-pressure liquid; a portion of the high-pressure liquid is returned to the top of the recovery tower, and the other portion of the high-pressure liquid is used as the industrial-grade hydrogen chloride product.

[0032] A portion of the light component at the top of the light component removal tower is directly discharged for recovery, while another portion of the light component at the top of the light component removal tower is condensed and refluxed back to the light component removal tower. A portion of the liquid in the bottom of the light component removal tower is discharged and recovered as chemical-grade hydrogen chloride product A, while another portion of the liquid in the bottom of the light component removal tower is partially vaporized. The resulting vapor phase is used as the rising vapor phase in the bottom of the light component removal tower, and the resulting liquid phase enters the purification tower for further purification.

[0033] A portion of the light component at the top of the refining tower is condensed and directly collected for recovery to obtain electronic-grade hydrogen chloride, while the other portion is refluxed back to the refining tower. A portion of the liquid in the bottom of the refining tower is directly collected for recovery, while the other portion is partially vaporized. The resulting vapor phase is used as the rising vapor phase in the bottom of the refining tower, and the resulting liquid phase is the heavy component, which is collected as chemical-grade hydrogen chloride product B.

[0034] In a second aspect, the present invention provides a system for producing electronic-grade hydrogen chloride and simultaneously producing chemical-grade and industrial-grade hydrogen chloride, comprising: a tail gas cryogenic recovery unit, a high-pressure light-light removal unit, and a product refining unit;

[0035] The exhaust gas cryogenic recovery unit includes a first cooler 23, a first reboiler 24, a stripping tower 25, a first compressor 26, a second cooler 27, a recovery tower 28, a second compressor 29, and a first condenser 30.

[0036] The first cooler 23 is used to cool and lower the tail gas; the stripping tower 25 is used to distill the cooled tail gas from the first cooler 23, and draw out hydrogen chloride dry gas from the top of the tower and bottom liquid from the bottom of the tower; the first reboiler 24 is used to vaporize part of the bottom liquid of the stripping tower 25; the first compressor 26 is used to pressurize the light components at the top of the stripping tower 25 to obtain a first high-pressure gas; the second cooler 27 is used to cool the first high-pressure gas obtained after compression by the first compressor 26; the recovery tower 28 is used to distill the first high-pressure gas from the second cooler 27, and draw out hydrogen chloride gas from the top of the tower, and the bottom liquid collected from the bottom of the tower is used as the reflux liquid of the stripping tower 25; the second compressor 29 is used to pressurize the hydrogen chloride gas drawn from the top of the recovery tower 28 to obtain a second high-pressure gas; the first condenser 30 is used to condense the second high-pressure gas.

[0037] The first cooler 23 is connected to the feed inlet at the top of the stripping tower 25; the discharge outlet at the top of the stripping tower 25 is connected to the feed inlet at the bottom of the recovery tower 28 via the first compressor 26 and the second cooler 27; the discharge outlet at the top of the recovery tower 28 is connected to the feed inlet at the middle of the first condenser 30 and the light-weight product removal tower 31 via the second compressor 29.

[0038] The high-pressure light-weight removal unit includes a light-weight removal tower 31, a second condenser 32, and a second reboiler 33.

[0039] The light component removal tower 31 is used to distill the high-pressure gas obtained from the second compressor 29 and draw out hydrogen chloride gas containing light components from the top of the tower. Part of the liquid collected from the bottom of the tower is used as product chemical grade hydrogen chloride A, and the other part is used as feed to the refining tower 34. The second condenser 32 is used to condense the light components collected from the top of the light component removal tower 31. The second reboiler 33 is used to partially vaporize the heavy components collected from the bottom of the light component removal tower 31, so that the resulting vapor phase is used as the rising vapor phase from the bottom of the light component removal tower 31, and the liquid phase enters the refining tower 34 for further refining.

[0040] The outlet at the top of the light-light-removal tower 31 is connected to the inlet at the top of the light-light-removal tower 31 via the second condenser 32; the outlet at the bottom of the light-light-removal tower 31 is connected to the inlet at the bottom of the light-light-removal tower 31 and the inlet at the middle of the refining tower 34 via the second reboiler 33.

[0041] The product refining unit includes a refining tower 34, a third condenser 35, and a third reboiler 36;

[0042] The refining tower 34 is used to distill part of the bottom liquid of the light-light-removal tower 31. After being liquefied by the third condenser 35, part of it is used as electronic-grade hydrogen chloride product and part of it is used as reflux liquid of the refining tower 34. The bottom liquid is partially vaporized by the third reboiler 36. The vapor phase is used as vapor phase reflux and the liquid phase is heavy component, which is collected as chemical-grade hydrogen chloride B.

[0043] The third condenser 35 is used to condense the light components collected from the top of the refining tower 34; the third reboiler 36 is used to partially vaporize the heavy components collected from the bottom of the refining tower 34, so that the obtained vapor phase is used as the rising vapor phase of the bottom of the refining tower 34, and the liquid phase is the heavy components, which are collected as chemical grade hydrogen chloride B.

[0044] The discharge port at the top of the refining tower 34 is connected to the feed port at the top of the refining tower 34 via the third condenser 35; the discharge port at the bottom of the refining tower 34 is connected to the feed port at the bottom of the refining tower 34 via the third reboiler 36.

[0045] According to the system for producing electronic-grade hydrogen chloride and simultaneously producing chemical-grade and industrial-grade hydrogen chloride provided by the present invention, the system further includes a mother liquor pipeline, a by-product pipeline, and a venting pipeline. The mother liquor pipeline is connected to the bottom outlet of the stripping tower 25, and is used to return the bottom liquid collected from the bottom of the stripping tower 25 as mother liquor to the chlorobenzene production system. The by-product pipeline is connected to the top outlet of the light component removal tower 31, and is used to absorb the light component-containing stream from the top of the light component removal tower 31 using water to obtain the by-product hydrochloric acid. The venting pipeline is connected to the bottom of the recovery tower 28 to treat substances accumulated during the distillation process.

[0046] In this invention, all equipment can be made of stainless steel and can be standardized equipment or general machinery, which greatly reduces equipment investment costs.

[0047] As a preferred embodiment of the present invention, the method for producing electronic-grade hydrogen chloride and simultaneously producing chemical-grade and industrial-grade hydrogen chloride using the above system includes:

[0048] Tail gas cryogenic recovery unit: After being cooled by the first cooler 23, the chlorobenzene tail gas directly enters the top of the stripping tower 25. The top of the tower operates at a low temperature, and the gas discharged from the top is a dry gas without mother liquor volatiles, mainly composed of hydrogen chloride and light components. It can be compressed to above 1.0 MPa by the membrane compressor of the first compressor 26 to obtain the first high-pressure gas. The first high-pressure gas is cooled by the second cooler 27 and then used as feed to the recovery tower 28 and as a heat source for the tower bottom. The bottom liquid of the recovery tower 28 is a high-pressure liquid, which, after throttling and expansion, becomes the reflux liquid of the stripping tower 25. The gas discharged from the top of the stripping tower is a dry gas without mother liquor volatiles, mainly composed of hydrogen chloride and light components. It can be compressed to above 4.0 MPa by the membrane compressor, which acts as the second compressor 29, to obtain the second high-pressure gas. Part of the second high-pressure gas is used as feed to the light component removal tower 31, and part is processed by the first condenser 30. The condensed liquid part is used as industrial-grade hydrogen chloride product, and part, after throttling and expansion, becomes the top reflux liquid of the recovery tower 28.

[0049] High-pressure light component removal unit: Part of the second high-pressure gas enters the light component removal tower 31 for distillation and hydrogen chloride gas containing light components is drawn off from the top of the tower. Part of the bottom liquid is used as product chemical-grade hydrogen chloride A, and the other part is used as feed to the refining tower 34. The second condenser 32 is used to condense the light components collected from the top of the light component removal tower 31. The second reboiler 33 is used to vaporize part of the heavy components collected from the bottom of the light component removal tower 31, so that the resulting vapor phase is used as the rising vapor phase of the bottom of the light component removal tower 31, part of the heavy components are used as chemical-grade hydrogen chloride A, and part of the heavy components enter the refining tower 34 for further refining.

[0050] Product refining unit: The refining tower 34 is used to distill part of the bottom liquid of the light component removal tower 31. After liquefaction by the third condenser 35, part of it is used as electronic grade hydrogen chloride product, part of it is used as reflux liquid of the refining tower 34, part of the bottom liquid is vaporized by the third reboiler 36 as vapor phase reflux, and part of the bottom liquid is heavy component, which is collected as chemical grade hydrogen chloride B.

[0051] Based on this, the technical solution of the present invention has the following advantages:

[0052] This invention provides a method and system for producing electronic-grade hydrogen chloride in conjunction with chemical-grade and industrial-grade hydrogen chloride. By optimizing the process flow, it utilizes chlorobenzene tail gas as raw material to produce electronic-grade, chemical-grade, and industrial-grade hydrogen chloride, forming a green and environmentally friendly circular economy. Furthermore, it features low equipment investment costs, low process production costs, and broad market prospects. The production process of this invention produces no waste gas, wastewater, or solid waste; the recovered mother liquor is returned to the chlorobenzene production system; the recovery rate of the main products, electronic-grade hydrogen chloride, chemical-grade hydrogen chloride, and industrial-grade hydrogen chloride, reaches 52%; the remaining discharged hydrogen chloride containing light components can be absorbed with water to obtain hydrochloric acid as a byproduct. The discharged light components are nitrogen, oxygen, and carbon dioxide, which do not pollute the environment, and all chlorobenzene tail gas can be recovered and reused. Attached Figure Description

[0053] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0054] Figure 1 This is a schematic diagram of the system process for producing electronic-grade hydrogen chloride and simultaneously producing chemical-grade and industrial-grade hydrogen chloride, as provided in Embodiment 1 of the present invention.

[0055] Figure label:

[0056] 1: Stripping tower feed; 2: Stripping tower bottom discharge (mother liquor); 3: Stripping tower top discharge; 4: Stripping tower reflux; 5: Recovery tower feed; 6: Recovery tower bottom discharge; 7: Recovery tower top discharge; 8: Recovery tower reflux; 9: Industrial grade hydrogen chloride; 10: Light component removal tower feed; 11: Light component removal tower bottom discharge; 12: Chemical grade hydrogen chloride A; 13: Light component removal tower top discharge; 14: Light component removal tower discharge; 15: Light component removal tower reflux; 16: Purifying tower feed; 17: Purifying tower bottom liquid; 18: Heavy component removal tower discharge (chemical grade) 19: Refining column bottom reflux; 20: Refining column top discharge; 21: Electronic grade hydrogen chloride; 22: Refining column top reflux; 23: First cooler; 24: First reboiler; 25: Stripping column; 26: First compressor; 27: Second cooler; 28: Recovery column; 29: Second compressor; 30: First condenser; 31: Light weight removal column; 32: Second condenser; 33: Second reboiler; 34: Refining column; 35: Third condenser; 36: Third reboiler; 37: Drain line. Detailed Implementation

[0057] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0058] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of the invention described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0059] Unless otherwise specified, all raw materials used in the examples and comparative examples are commercially available conventional raw materials, and the technical means used are conventional means well known to those skilled in the art.

[0060] In the following examples, the feed gas is the tail gas from the chlorobenzene production process, and its composition is shown in Table 1:

[0061] Mass flow rate: 2000 kg / h; temperature: 20℃; pressure: 0.1MPa; phase: gas phase.

[0062] Table 1. Composition of tail gas from chlorobenzene production process

[0063]

[0064] Example 1

[0065] This embodiment provides a system for producing electronic-grade hydrogen chloride and simultaneously producing chemical-grade and industrial-grade hydrogen chloride. The process flow diagram of the system is shown below. Figure 1 As shown, it includes: a low-temperature exhaust gas recovery unit, a high-pressure light-duty removal unit, and a product refining unit;

[0066] The exhaust gas cryogenic recovery unit includes a first cooler 23, a first reboiler 24, a stripping tower 25, a first compressor 26, a second cooler 27, a recovery tower 28, a second compressor 29, and a first condenser 30.

[0067] The first cooler 23 is used to cool and reduce the tail gas to obtain stripping tower feed 1; the stripping tower 25 is used to distill the cooled tail gas from the first cooler 23, and draw out hydrogen chloride dry gas (i.e., stripping tower top discharge 3) from the top of the tower and draw out bottom liquid (i.e., stripping tower bottom discharge liquid (mother liquor) 2) from the bottom of the tower; the first reboiler 24 is used to vaporize part of the bottom liquid of the stripping tower 25; the first compressor 26 is used to pressurize the light components at the top of the stripping tower 25 to obtain a first high-pressure gas; the second cooler 27 is used to cool the first high-pressure gas obtained after compression by the first compressor 26 to obtain light component removal tower feed 10; the recovery tower 28 The first high-pressure gas from the second cooler 27 is used for distillation, and hydrogen chloride gas is drawn from the top of the column (i.e., recovery column top discharge 7), and the bottom liquid collected from the bottom of the column (i.e., recovery column bottom discharge 6) is used as the reflux liquid of the stripping column 25 (i.e., stripping column reflux 4); the second compressor 29 is used to pressurize the hydrogen chloride gas drawn from the top of the recovery column 28 to obtain a second high-pressure gas (i.e., light dust removal column feed 10); the first condenser 30 is used to condense a portion of the second high-pressure gas, so that the resulting liquid phase is used as the product industrial-grade hydrogen chloride (i.e., industrial-grade hydrogen chloride 9), and the other part of the liquid phase is used as the reflux liquid of the recovery column (i.e., recovery column reflux 8).

[0068] The first cooler 23 is connected to the feed inlet at the top of the stripping tower 25; the discharge outlet at the top of the stripping tower 25 is connected to the feed inlet at the bottom of the recovery tower 28 via the first compressor 26 and the second cooler 27; the discharge outlet at the top of the recovery tower 28 is connected to the feed inlet at the middle of the first condenser 30 and the light-weight product removal tower 31 via the second compressor 29.

[0069] The high-pressure light-weight removal unit includes a light-weight removal tower 31, a second condenser 32, and a second reboiler 33.

[0070] The light component removal tower 31 is used to distill the high-pressure gas obtained from the second compressor 29 and draw out hydrogen chloride gas containing light components from the top of the tower (i.e., the top discharge 13 of the light component removal tower). The bottom liquid collected from the bottom of the tower (i.e., the bottom discharge liquid 11 of the light component removal tower) is used as the product chemical grade hydrogen chloride A (chemical grade hydrogen chloride A 12), and the other part is used as the feed of the purification tower 34 (i.e., the feed 16 of the purification tower). The second condenser 32 is used to condense part of the light components collected from the top of the light component removal tower 31 (i.e., the stream 13) (to obtain the reflux stream 15 of the light component removal tower). The second reboiler 33 is used to partially vaporize the heavy components collected from the bottom of the light component removal tower 31, so that the resulting vapor phase is used as the rising vapor phase of the bottom of the light component removal tower 31, and the liquid phase enters the purification tower 34 for further purification.

[0071] The outlet at the top of the light-light-removal tower 31 is connected to the inlet at the top of the light-light-removal tower 31 via the second condenser 32; the outlet at the bottom of the light-light-removal tower 31 is connected to the inlet at the bottom of the light-light-removal tower 31 and the inlet at the middle of the refining tower 34 via the second reboiler 33.

[0072] The product refining unit includes a refining tower 34, a third condenser 35, and a third reboiler 36;

[0073] The refining column 34 is used to distill part of the bottom liquid of the light component removal column 31. The light component collected from the top of the column (i.e., stream 20) is liquefied by the third condenser 35, and part of it is used as electronic-grade hydrogen chloride product (i.e., stream 21), and part of it is used as reflux liquid of the refining column 34 (i.e., stream 22). The bottom liquid (i.e., stream 17) is partially vaporized by the third reboiler 36. The vapor phase is used as vapor phase reflux (i.e., stream 19), and the liquid phase is collected as heavy component (chemical-grade hydrogen chloride B) (i.e., stream 18). The third condenser 35 is used to condense the light component collected from the top of the refining column 34. The third reboiler 36 is used to partially vaporize the heavy component collected from the bottom of the refining column 34, so that the resulting vapor phase is used as the rising vapor phase of the bottom of the refining column 34, and the liquid phase is collected as the heavy component (chemical-grade hydrogen chloride B).

[0074] The discharge port at the top of the refining tower 34 is connected to the feed port at the top of the refining tower 34 via the third condenser 35; the discharge port at the bottom of the refining tower 34 is connected to the feed port at the bottom of the refining tower 34 via the third reboiler 36.

[0075] According to the system for producing electronic-grade hydrogen chloride and simultaneously producing chemical-grade and industrial-grade hydrogen chloride provided by the present invention, the system further includes a mother liquor pipeline and a by-product pipeline. The mother liquor pipeline is connected to the bottom outlet of the stripping tower 25 and is used to return the bottom liquid collected from the bottom of the stripping tower 25 as mother liquor to the chlorobenzene production system. The by-product pipeline is connected to the top outlet of the light component removal tower 31 and is used to absorb the light component-containing stream water from the top of the light component removal tower 31 to obtain hydrochloric acid as a by-product.

[0076] As a preferred embodiment of the present invention, the method for producing electronic-grade hydrogen chloride and simultaneously producing chemical-grade and industrial-grade hydrogen chloride includes the following steps:

[0077] The tail gas cryogenic recovery section: After being cooled by the first cooler 23, the chlorobenzene tail gas directly enters the top of the stripping tower 25. The top of the tower operates at a low temperature, and the gas discharged from the top is a dry gas without mother liquor volatiles, mainly composed of hydrogen chloride and light components. It can be compressed to above 1.0 MPa by the membrane compressor of the first compressor 26 to obtain the first high-pressure gas. The first high-pressure gas is cooled by the second cooler 27 and then used as feed to the recovery tower 28 and as a heat source for the tower bottom. The bottom liquid of the recovery tower 28 is a high-pressure liquid, which, after throttling and expansion, becomes the reflux liquid of the stripping tower 25. The gas discharged from the top of the stripping tower is a dry gas without mother liquor volatiles, mainly composed of hydrogen chloride and light components. It can be compressed to above 4.0 MPa by the membrane compressor, which acts as the second compressor 29, to obtain the second high-pressure gas. Part of the second high-pressure gas is used as feed to the light component removal tower 31, and part is processed by the first condenser 30. The condensed liquid part is used as industrial-grade hydrogen chloride product, and part, after throttling and expansion, becomes the top reflux liquid of the recovery tower 28.

[0078] High-pressure light component removal section: The second high-pressure gas portion enters the light component removal tower 31 for distillation and hydrogen chloride gas containing light components is drawn off from the top of the tower. The bottom liquid collected from the bottom of the tower is used as product chemical-grade hydrogen chloride A, and the other portion is used as feed to the refining tower 34. The second condenser 32 is used to condense the light components collected from the top of the light component removal tower 31. The second reboiler 33 is used to vaporize a portion of the heavy components collected from the bottom of the light component removal tower 31, so that the resulting vapor phase is used as the rising vapor phase of the bottom of the light component removal tower 31, a portion of the heavy components is used as chemical-grade hydrogen chloride A, and a portion of the heavy components enters the refining tower 34 for further refining.

[0079] Product refining section: The refining tower 34 is used to distill part of the bottom liquid of the light component removal tower 31. After liquefaction by the third condenser 35, part of it is used as electronic grade hydrogen chloride product, part of it is used as reflux liquid of the refining tower 34, part of the bottom liquid is vaporized by the third reboiler 36 as vapor phase reflux, and part of the bottom liquid is collected as heavy component (chemical grade hydrogen chloride B).

[0080] The vapor phase feed pressure of the stripping tower is approximately 0.12 MPa, and the temperature is approximately 10°C; the pressure of the liquid discharged from the bottom of the stripping tower is approximately 0.12 MPa, and the temperature is approximately 30°C; the pressure of the exhaust gas from the top of the stripping tower is approximately 0.12 MPa, and the temperature is approximately -85°C; the pressure of the reflux from the top of the stripping tower is approximately 0.12 MPa, and the temperature is approximately -85°C; the reflux ratio is 0.5.

[0081] The feed pressure of the recovery tower is approximately 0.18 MPa, and the temperature is approximately 55°C; the pressure of the liquid collected at the bottom of the recovery tower is approximately 0.18 MPa, and the temperature is approximately -30°C; the pressure of the exhaust gas at the top of the recovery tower is approximately 0.18 MPa, and the temperature is approximately -30°C; the pressure of the reflux at the top of the recovery tower is approximately 0.18 MPa, and the temperature is approximately -30°C; the reflux ratio is 0.5.

[0082] The feed pressure of the light-weight liquid removal tower is approximately 4.2 MPa and the temperature is approximately 20°C; the pressure of the liquid collected at the bottom of the light-weight liquid removal tower is approximately 4.2 MPa and the temperature is approximately 20°C; the pressure of the exhaust gas at the top of the light-weight liquid removal tower is approximately 4.2 MPa and the temperature is approximately 20°C; the pressure of the reflux at the top of the light-weight liquid removal tower is approximately 4.2 MPa and the temperature is approximately 20°C; the reflux ratio is 9.

[0083] The feed pressure of the refining tower is approximately 4.2 MPa and the temperature is approximately 20°C; the pressure of the liquid collected at the bottom of the refining tower is approximately 4.2 MPa and the temperature is approximately 20°C; the pressure of the exhaust gas at the top of the refining tower is approximately 4.2 MPa and the temperature is approximately 20°C; the pressure of the reflux at the top of the refining tower is approximately 4.2 MPa and the temperature is approximately 20°C; the reflux ratio is 2.

[0084] Send the raw gas into, for example Figure 1 The system shown was processed using the method described above, and the process data are shown in Table 2. The results show that the specifications of the obtained product meet the 5.5N standard specified in the national standard GB / T 14602-2014.

[0085] Table 2

[0086]

[0087] When the continuous distillation conditions are controlled within the preferred range defined by the present invention, technical effects comparable to those of Example 1 can be obtained, namely, the production of electronic hydrogen chloride and the co-production of industrial-grade and chemical-grade hydrogen chloride.

[0088] Example 2

[0089] This embodiment provides a method for producing electronic-grade hydrogen chloride and simultaneously producing chemical-grade and industrial-grade hydrogen chloride. The only difference between this method and Example 1 is that the reflux ratio of the light-light removal tower is 5.

[0090] The process data are shown in Table 3. The results show that when the reflux ratio is reduced to 5, the carbon dioxide content of chemical-grade hydrogen chloride and electronic-grade hydrogen chloride products increases significantly. Among them, the electronic-grade hydrogen chloride product will not meet the national standard requirements for the concentration of electronic-grade hydrogen chloride.

[0091] Table 3

[0092]

[0093] Example 3

[0094] This embodiment provides a method for producing electronic-grade hydrogen chloride and simultaneously producing chemical-grade and industrial-grade hydrogen chloride. The only difference between this method and Example 1 is that the operating pressure at the top of the light-light removal tower is 6 MPa.

[0095] The operating process data are shown in Table 4. The results show that when the pressure of the light-duty removal tower increases to 6 MPa, the carbon dioxide content of both chemical-grade hydrogen chloride and electronic-grade hydrogen chloride products increases. Among them, the electronic-grade hydrogen chloride product will not meet the national standard requirements for the concentration of electronic-grade hydrogen chloride.

[0096] Table 4

[0097]

[0098] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for producing electronic-grade hydrogen chloride and simultaneously producing chemical-grade and industrial-grade hydrogen chloride, characterized in that, include: The tail gas emitted from the industrial production of chlorobenzene is used as raw material and fed into a stripping tower. The gas extracted from the top of the stripping tower is compressed to obtain a first high-pressure gas. The first high-pressure gas is introduced into the recovery tower, and the gas extracted from the top of the recovery tower is compressed to obtain the second high-pressure gas. A portion of the second high-pressure gas is passed into the light-light gas removal tower, and the other portion of the second high-pressure gas is condensed to obtain industrial-grade hydrogen chloride product. A portion of the liquid from the bottom of the light-light removal tower is collected as chemical-grade hydrogen chloride product A. Another portion of the liquid from the bottom of the light-light removal tower is partially vaporized, and the resulting vapor phase is used as the rising vapor phase in the bottom of the light-light removal tower. The resulting liquid phase enters the purification tower for further purification. Electronic-grade hydrogen chloride product is collected from the top of the purification tower, and heavy components are collected from the bottom of the purification tower as chemical-grade hydrogen chloride product B. The exhaust gas composition includes hydrogen chloride, chlorine, organic gases, nitrogen, oxygen, carbon dioxide, and water. The operating conditions for the stripping tower include: operating pressure at the top of the tower is 0.07~0.17MPa, operating temperature at the top of the tower is -90~-75℃, and reflux ratio is 0.4~1. The feed pressure of the recovery tower is above 1 MPa, and the feed temperature is 35~55℃; the pressure of the bottom liquid collected from the recovery tower is above 1 MPa, and the temperature of the bottom liquid collected from the tower is -35~-20℃; the exhaust pressure of the top of the recovery tower is above 1 MPa, and the exhaust temperature of the top of the tower is -35~-20℃; the reflux pressure of the top of the recovery tower is above 1 MPa, and the reflux temperature of the top of the tower is -35~-20℃; the reflux ratio is 0.4~1. The feed pressure of the refining column is 3.9~4.9MPa, and the feed temperature is 15~30℃; the pressure of the bottom product of the refining column is 3.9~4.9MPa, and the temperature of the bottom product is 15~30℃; the pressure of the exhaust gas at the top of the refining column is 3.9~4.9MPa, and the temperature of the exhaust gas at the top of the column is 15~30℃; the pressure of the reflux at the top of the refining column is 3.9~4.9MPa, and the temperature of the reflux at the top of the column is 15~30℃; the reflux ratio is 2~5. The operating conditions for controlling the light component removal tower include: tower top operating pressure of 3.9~4.5MPa, tower top operating temperature of 15~30℃, and reflux ratio of 8~12; The feed pressure of the light-weight liquid removal tower is 3.9~4.5MPa, and the feed temperature is 15~30℃; the pressure of the bottom product of the light-weight liquid removal tower is 3.9~4.5MPa, and the temperature of the bottom product is 15~30℃; the pressure of the exhaust gas at the top of the light-weight liquid removal tower is 3.9~4.5MPa, and the temperature of the exhaust gas at the top of the tower is 15~30℃; the pressure of the reflux at the top of the light-weight liquid removal tower is 3.9~4.5MPa, and the temperature of the reflux at the top of the tower is 15~30℃. The pressure of the vapor phase feed in the stripping tower is 0.07~0.17MPa, and the temperature of the vapor phase feed is 0~10℃; the pressure of the liquid discharged from the bottom of the stripping tower is 0.07~0.17MPa, and the temperature of the liquid discharged from the bottom of the stripping tower is 25~40℃; the pressure of the exhaust gas at the top of the stripping tower is 0.07~0.17MPa, and the temperature of the exhaust gas at the top of the tower is -90~-75℃; the pressure of the reflux at the top of the stripping tower is 0.07~0.17MPa, and the temperature of the reflux at the top of the tower is -90~-75℃.

2. The method for producing electronic-grade hydrogen chloride and simultaneously producing chemical-grade and industrial-grade hydrogen chloride according to claim 1, characterized in that, The exhaust gas composition, based on molar content, includes: HCl not less than 90%, Cl2 not more than 0.5%, organic gas content not more than 0.5%, and the content of other components less than 1%.

3. The method for producing electronic-grade hydrogen chloride and simultaneously producing chemical-grade and industrial-grade hydrogen chloride according to claim 1, characterized in that, The water molar content in the exhaust gas is less than 1%, and the carbon dioxide molar content in the exhaust gas is less than 0.06%.

4. The method for producing electronic-grade hydrogen chloride and simultaneously producing chemical-grade and industrial-grade hydrogen chloride according to claim 1 or 2, characterized in that, The water content in the feed to the recovery tower is less than 0.001% in terms of molar content. And / or, in terms of molar content, the content of chlorine and organic gases in the feed to the light-removal tower is less than 0.00001%; And / or, in molar terms, the carbon dioxide content in the feed to the purification tower is less than 0.00004%.

5. The method for producing electronic-grade hydrogen chloride and simultaneously producing chemical-grade and industrial-grade hydrogen chloride according to claim 1, characterized in that, include: The tail gas emitted from the industrial production of chlorobenzene is used as raw material and fed into the top of the stripping tower. The light components at the top of the stripping tower are compressed to obtain a first high-pressure gas. The first high-pressure gas is introduced into the bottom of the recovery tower, and the bottom liquid of the recovery tower is throttled and expanded before flowing back to the stripping tower. The light components at the top of the recovery tower are compressed to obtain the second high-pressure gas. A portion of the second high-pressure gas is passed into the light-weight gas removal tower, and the other portion of the second high-pressure gas is condensed to obtain a high-pressure liquid; a portion of the high-pressure liquid is returned to the top of the recovery tower, and the other portion of the high-pressure liquid is used as the industrial-grade hydrogen chloride product. A portion of the light component at the top of the light component removal tower is directly discharged for recovery, while the other portion of the light component at the top of the light component removal tower is condensed and refluxed back to the light component removal tower. A portion of the liquid from the bottom of the light-light removal tower is collected as chemical-grade hydrogen chloride product A. The other portion of the liquid from the bottom of the light-light removal tower is partially vaporized, and the resulting vapor phase is used as the rising vapor phase in the bottom of the light-light removal tower. The resulting liquid phase enters the purification tower for further purification. A portion of the light component at the top of the refining tower is condensed and directly collected for recovery to obtain electronic-grade hydrogen chloride, while the other portion is refluxed back to the refining tower. A portion of the liquid in the bottom of the refining tower is directly collected and recovered, while the other portion is partially vaporized. The resulting vapor phase is used as the rising vapor phase in the bottom of the refining tower, and the resulting liquid phase is the heavy component, which is collected as chemical-grade hydrogen chloride B.

6. A system used in the method for producing electronic-grade hydrogen chloride and simultaneously producing chemical-grade and industrial-grade hydrogen chloride as described in any one of claims 1-5, characterized in that, include: The exhaust gas cryogenic recovery unit, the high-pressure light-duty removal unit, and the product refining unit; The exhaust gas cryogenic recovery unit includes a first cooler (23), a first reboiler (24), a stripping tower (25), a first compressor (26), a second cooler (27), a recovery tower (28), a second compressor (29), and a first condenser (30). The first cooler (23) is used to cool and reduce the temperature of the tail gas; the stripping tower (25) is used to distill the cooled tail gas from the first cooler (23), and draw out hydrogen chloride dry gas from the top of the tower and bottom liquid from the bottom of the tower; the first reboiler (24) is used to vaporize part of the bottom liquid of the stripping tower (25); the first compressor (26) is used to pressurize the light components at the top of the stripping tower (25) to obtain a first high-pressure gas; the second cooler (27) is used to cool and reduce the temperature of the tail gas. The first high-pressure gas obtained after compression by a compressor (26) is cooled; the recovery tower (28) is used to distill the first high-pressure gas from the second cooler (27) and draw out hydrogen chloride gas from the top of the tower, and the bottom liquid collected from the bottom of the tower is used as the reflux liquid of the stripping tower (25); the second compressor (29) is used to pressurize the hydrogen chloride gas drawn from the top of the recovery tower (28) to obtain a second high-pressure gas; the first condenser (30) is used to condense the second high-pressure gas; The first cooler (23) is connected to the feed inlet at the top of the stripping tower (25); the discharge outlet at the top of the stripping tower (25) is connected to the feed inlet at the bottom of the recovery tower (28) via the first compressor (26) and the second cooler (27); the discharge outlet at the top of the recovery tower (28) is connected to the feed inlet at the middle of the first condenser (30) and the light-weight removal tower (31) via the second compressor (29); The high-pressure light-weight removal unit includes a light-weight removal tower (31), a second condenser (32), and a second reboiler (33). The light component removal tower (31) is used to distill the high-pressure gas obtained from the second compressor (29) and draw out hydrogen chloride gas containing light components from the top of the tower. Part of the liquid collected from the bottom of the tower is used as product chemical grade hydrogen chloride A, and the other part is used as feed to the refining tower (34). The second condenser (32) is used to condense the light components collected from the top of the light component removal tower (31). The second reboiler (33) is used to partially vaporize the heavy components collected from the bottom of the light component removal tower (31) so that the resulting vapor phase is used as the rising vapor phase of the bottom of the light component removal tower (31), and the liquid phase enters the refining tower (34) for further refining. The outlet at the top of the light-light removal tower (31) is connected to the inlet at the top of the light-light removal tower (31) via the second condenser (32); the outlet at the bottom of the light-light removal tower (31) is connected to the inlet at the bottom of the light-light removal tower (31) and the inlet at the middle of the refining tower (34) via the second reboiler (33). The product refining unit includes a refining tower (34), a third condenser (35), and a third reboiler (36). The refining tower (34) is used to distill part of the bottom liquid of the light removal tower (31). After being liquefied by the third condenser (35), part of it is used as electronic grade hydrogen chloride product and part of it is used as reflux liquid of the refining tower (34). The bottom liquid is partially vaporized by the third reboiler (36). The vapor phase is used as vapor phase reflux and the liquid phase is heavy component, which is collected as chemical grade hydrogen chloride B. The third condenser (35) is used to condense the light components collected from the top of the refining tower (34); the third reboiler (36) is used to partially vaporize the heavy components collected from the bottom of the refining tower (34), so that the obtained vapor phase is used as the rising vapor phase of the bottom of the refining tower (34), and the liquid phase is the heavy components, which are collected as chemical grade hydrogen chloride B. The outlet at the top of the refining tower (34) is connected to the inlet at the top of the refining tower (34) via the third condenser (35); the outlet at the bottom of the refining tower (34) is connected to the inlet at the bottom of the refining tower (34) via the third reboiler (36).

7. The system according to claim 6, characterized in that, The system is also equipped with a mother liquor pipeline and a by-product pipeline. The mother liquor pipeline is connected to the bottom outlet of the stripping tower (25) and is used to send the bottom liquid collected from the bottom of the stripping tower (25) back to the chlorobenzene production system as mother liquor. The by-product pipeline is connected to the top outlet of the light component removal tower (31) and is used to absorb the light component-containing stream from the top of the light component removal tower (31) with water and send it out as hydrochloric acid product.

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