Method and system for producing electronic-grade hydrogen chloride and co-producing chemical-grade hydrogen chloride and industrial-grade hydrogen chloride

Abstract

The invention relates to the technical field of hydrogen chloride purification, in particular to a method and a system for producing electronic-grade hydrogen chloride and co-producing chemical-grade hydrogen chloride and industrial-grade hydrogen chloride. According to the method, the process flow is optimized, the electronic hydrogen chloride, the chemical-grade hydrogen chloride and the industrial-grade hydrogen chloride are produced by using the chlorobenzene tail gas as the raw material, green and environment-friendly circular economy is formed, the equipment investment cost is low, the process production cost is low, and the market prospect is wide. In the production process, no three wastes are discharged, and the recovered mother liquor is returned to a chlorobenzene production system, so that the recovery rate of chlorobenzene is increased; the recovery rate of the main products of electronic hydrogen chloride, chemical-grade hydrogen chloride and industrial-grade hydrogen chloride reaches 52%; after hydrogen chloride containing light components is absorbed by water, a byproduct hydrochloric acid can be obtained, and the discharged light components are nitrogen, oxygen and carbon dioxide which are pollution-free to the environment; the chlorobenzene tail gas can be completely recycled.

Description

Technical Field

[0001] The invention relates to the technical field of hydrogen chloride purification, and in particular to a method and system for producing electronic grade hydrogen chloride and co-producing chemical grade hydrogen chloride and industrial grade hydrogen chloride. Background Art

[0002] Hydrogen chloride for the electronics industry (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 the surface of semiconductor materials, as an auxiliary agent in the epitaxial growth process, and as a gas phase transfer medium in chemical vapor deposition and other processes to participate in the deposition of integrated circuit semiconductor materials, vapor 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, synthesis of pharmaceutical intermediates, and can also be used 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, polyvinyl chloride, etc.; in the pharmaceutical industry, it is used to prepare certain drugs and medicines; in the metal processing industry, it is used for degreasing and rust removal during cold rolling and heat treatment of steel.

[0003] At present, the prior art has disclosed a variety of methods for purifying electronic-grade hydrogen chloride by continuous distillation. For example, CN 110255501 A discloses a method for preparing electronic-grade high-purity hydrogen chloride, which uses toluene and chlorine to carry out chlorination reaction to produce chlorotoluene, and simultaneously produces byproduct hydrogen chloride gas. The byproduct is used as a raw material, and the raw material is dehydrated, liquefied, distilled to remove light components, and distilled to remove heavy components to obtain electronic-grade high-purity hydrogen chloride. However, it is necessary to remove the moisture in the chlorotoluene tail gas by molecular sieve, and then to remove other impurities by distillation. When the water content of the tail gas is high, other impurities may be introduced due to the reaction of hydrogen chloride with an adsorbent, thereby increasing the subsequent separation burden, and making it difficult to control the content of particles and metal ions. CN 114634163 A discloses a production device and method for manufacturing electronic-grade hydrogen chloride, which uses byproducts and recycled hydrogen chloride or synthetic hydrogen chloride as raw materials, uses activated carbon or silica gel to remove moisture from industrial tail gas, and is assisted by distillation and reaction to remove C2 and other impurities, but the distillation and separation burden of this method is significantly larger.

[0004] It can be seen that there is still room for further improvement in the prior art in preparing electronic grade hydrogen chloride. Summary of the invention

[0005] In order to solve the above problems in the prior art, the present invention provides a method and system for producing electronic-grade hydrogen chloride and co-producing chemical-grade hydrogen chloride and industrial-grade hydrogen chloride. Without introducing a third medium, dehydration and impurity removal are performed through distillation technology, so that the purity and cleanliness of electronic-grade products can be controlled and the uniformity and stability of indicators can be ensured.

[0006] Based on this, the present invention has the following technical solutions: In a first aspect, the present invention provides a method for producing electronic grade hydrogen chloride and co-producing chemical grade hydrogen chloride and industrial grade hydrogen chloride, comprising: The tail gas emitted from the industrial production of chlorobenzene is introduced into a stripping tower as a raw material, and the gas produced from the top of the stripping tower is compressed to obtain a first high-pressure gas; Passing the first high-pressure gas into a recovery tower, and compressing the gas produced from the top of the recovery tower to obtain a second high-pressure gas; Passing a portion of the second high-pressure gas into a light-removal tower, and condensing another portion of the second high-pressure gas to obtain an industrial-grade hydrogen chloride product; A portion of the lightness removal tower bottom liquid is discharged and recovered as a chemical grade hydrogen chloride product, another portion of the lightness removal tower bottom liquid is partially vaporized, the obtained vapor phase is used as the rising vapor phase of the lightness removal tower bottom, the obtained liquid phase enters the refining tower for further refining, and the electronic grade hydrogen chloride product is extracted from the top of the refining tower; The tail gas composition includes hydrogen chloride, chlorine, organic gas, nitrogen, oxygen, carbon dioxide and water.

[0007] In the present 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%.

[0008] In the present invention, the raw material is derived from the industrial tail gas emitted by the industrial production of chlorobenzene, and its main components include two parts: the mother liquor volatile matter (including unreacted raw material chlorine, benzene and product chlorobenzene) brought out by the reactor and the air leaked into the system. The use of chlorobenzene tail gas as a raw material to prepare high value-added electronic grade hydrogen chloride will be the key to forming a green and environmentally friendly circular economy, thereby achieving emission reduction and high value-added utilization of tail waste.

[0009] According to the method for producing electronic grade hydrogen chloride and co-producing chemical grade hydrogen chloride and industrial grade hydrogen chloride provided by the present invention, the tail gas composition includes, by molar content, HCl not less than 90%, Cl2 not higher than 0.5%, organic gas content not higher than 0.5%, and the content of other components is 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%.

[0010] According to the method for producing electronic grade hydrogen chloride and co-producing chemical grade hydrogen chloride and industrial grade hydrogen chloride provided by the present invention, the water content in the recovery tower feed is less than 0.001% by molar content.

[0011] According to the method for producing electronic grade hydrogen chloride and co-producing chemical grade hydrogen chloride and industrial grade hydrogen chloride provided by the present invention, the content of chlorine and organic gas in the feed of the lightness removal tower is less than 0.00001% by molar content.

[0012] According to the method for producing electronic grade hydrogen chloride and co-producing chemical grade hydrogen chloride and industrial grade hydrogen chloride provided by the present invention, the carbon dioxide content in the feed to the refining tower is less than 0.00004% by molar content.

[0013] In the present invention, the raw material chlorobenzene tail gas contains water and a relatively high concentration of carbon dioxide, wherein the water-containing hydrogen chloride gas will cause corrosion to the stainless steel tower equipment, and the boiling point of carbon dioxide (the boiling point at normal pressure is -78.45°C) is relatively close to the boiling point of hydrogen chloride (the boiling point at normal pressure is -85°C), and it is difficult to separate from hydrogen chloride. According to a large number of studies, the present invention has found that in the process flow described in the present invention, by optimizing the operating conditions of the light removal tower, it can help to separate carbon dioxide and hydrogen chloride, and thus make the carbon dioxide concentration of electronic-grade products meet the national standard requirements. As for the removal of moisture, the present invention controls the operating conditions of the stripping tower to remove moisture to an extremely low concentration in the stripping tower, thereby minimizing the corrosion of moisture to the equipment, saving costs on the one hand, and controlling the content of metal ions in the product on the other hand.

[0014] According to the method for producing electronic grade hydrogen chloride and co-producing chemical grade hydrogen chloride and industrial grade hydrogen chloride provided by the present invention, the operating conditions of the lightness removal tower are controlled as follows: the tower top operating pressure is 3.9-4.5 MPa, the tower top operating temperature is 15-30° C., and the reflux ratio is 8-12.

[0015] 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 numerical range with any two of the above values ​​as endpoints; the tower top operating temperature can be any value among 15°C, 16°C, 17°C, 18°C, 19°C, 20°C, 21°C, 22°C, 23°C, 24°C, 25°C, 26°C, 27°C, 28°C, 29°C, and 30°C, or a numerical range 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 numerical range with any two of the above values ​​as endpoints.

[0016] According to the method for producing electronic-grade hydrogen chloride and co-producing chemical-grade hydrogen chloride and industrial-grade hydrogen chloride provided by the present invention, the feed pressure of the lightness removal tower is 3.9-4.9 MPa, and the feed temperature is 15-30° C.; the pressure of the bottom produced liquid of the lightness removal tower is 3.9-4.9 MPa, and the temperature of the bottom produced liquid is 15-30° C.; the pressure of the top exhaust gas of the lightness removal tower is 3.9-4.9 MPa, and the temperature of the top exhaust gas is 15-30° C.; the pressure of the top reflux of the lightness removal tower is 3.9-4.9 MPa, and the temperature of the top reflux is 15-30° C.

[0017] According to the method for producing electronic grade hydrogen chloride and co-producing chemical grade hydrogen chloride and industrial grade hydrogen chloride provided by the present invention, the operating conditions of the stripping tower are controlled as follows: the tower top operating pressure is 0.1-0.5 MPa, the tower top operating temperature is -90--75°C, and the reflux ratio is 0.4-1.

[0018] Specifically, the tower top operating pressure can be any value among 0.1MPa, 0.2MPa, 0.3MPa, 0.4MPa, and 0.5MPa, or a numerical range with any two of the above values ​​as endpoints; the tower top operating temperature can be any value among -90°C, -89°C, -88°C, -87°C, -86°C, -85°C, -84°C, -83°C, -82°C, -81°C, -80°C, -79°C, -78°C, -77°C, -76°C, and -75°C, or a numerical range 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 numerical range with any two of the above values ​​as endpoints.

[0019] According to the method for producing electronic grade hydrogen chloride and co-producing chemical grade hydrogen chloride and industrial grade hydrogen chloride provided by the present invention, the pressure of the vapor phase feed of the stripping tower is 0.07~0.17MPa, and the temperature of the vapor phase feed is 0~10°C; the pressure of the bottom discharge liquid of the stripping tower is 0.07~0.17MPa, and the temperature of the bottom discharge liquid is 25~40°C; the pressure of the top exhaust of the stripping tower is 0.07~0.17MPa, and the temperature of the top exhaust is -90~-75°C; the pressure of the top reflux of the stripping tower is 0.07~0.17MPa, and the temperature of the top reflux is -90~-75°C.

[0020] According to the method for producing electronic grade hydrogen chloride and co-producing chemical grade hydrogen chloride and industrial grade hydrogen chloride provided by the present invention, the pressure of the feed of the recovery tower is 0.08~0.18MPa, and the temperature of the feed is 35~55°C; the pressure of the produced liquid at the bottom of the recovery tower is 0.08~0.18MPa, and the temperature of the produced liquid at the bottom of the recovery tower is -35~-20°C; the pressure of the exhaust gas at the top of the recovery tower is 0.08~0.18MPa, and the temperature of the exhaust gas at the top of the recovery tower is -35~-20°C; the pressure of the reflux at the top of the recovery tower is 0.08~0.18MPa, and the temperature of the reflux at the top of the recovery tower is -35~-20°C; and the reflux ratio is 0.4~1.

[0021] According to the method for producing electronic-grade hydrogen chloride and co-producing chemical-grade hydrogen chloride and industrial-grade hydrogen chloride provided by the present invention, the pressure of the feed of the refining tower is 3.9-4.9 MPa, and the temperature of the feed is 15-30° C.; the pressure of the bottom produced liquid of the refining tower is 3.9-4.9 MPa, and the temperature of the bottom produced liquid is 15-30° C.; the pressure of the top exhaust of the refining tower is 3.9-4.9 MPa, and the temperature of the top exhaust is 15-30° C.; the pressure of the top reflux of the refining tower is 3.9-4.9 MPa, and the temperature of the top reflux is 15-30° C.; and the reflux ratio is 2-5.

[0022] The method for producing electronic grade hydrogen chloride and co-producing chemical grade hydrogen chloride and industrial grade hydrogen chloride provided by the present invention comprises: The tail gas emitted from the industrial production of chlorobenzene is introduced into the top of the stripping tower as a raw material, and 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, the kettle liquid of the recovery tower is throttled and expanded and then refluxed to the stripping tower, and the light component at the top of the recovery tower is compressed to obtain the second high-pressure gas; Passing a portion of the second high-pressure gas into a light-removing tower, and condensing another portion of the second high-pressure gas to obtain a high-pressure liquid; a portion of the high-pressure liquid is refluxed to the top of the recovery tower, and another portion of the high-pressure liquid is used as the industrial-grade hydrogen chloride product; A part of the light components at the top of the light-removing tower is directly discharged for recovery, and another part of the light components at the top of the light-removing tower is condensed and refluxed to the light-removing tower; a part of the bottom liquid of the light-removing tower is discharged and recovered as a chemical-grade hydrogen chloride product A, and another part of the bottom liquid of the light-removing tower is partially vaporized, and the obtained vapor phase is used as the rising vapor phase of the bottom of the light-removing tower, and the obtained liquid phase enters a refining tower for further refining.

[0023] A part of the light component at the top of the refining tower is condensed and directly recovered to obtain electronic grade hydrogen chloride, and the other part is refluxed to the refining tower; a part of the liquid in the bottom of the refining tower is directly recovered, and the other part is partially vaporized, and the obtained vapor phase is used as the rising vapor phase of the bottom of the refining tower, and the obtained liquid phase is the heavy component, which is recovered as chemical grade hydrogen chloride product B.

[0024] In a second aspect, the present invention provides a system for producing electronic grade hydrogen chloride and co-producing chemical grade hydrogen chloride and industrial grade hydrogen chloride, comprising: a tail gas low temperature recovery unit, a high pressure light removal unit and a product refining unit; The tail gas low temperature 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 the tail gas; the stripping tower 25 is used to rectify the cooled tail gas from the first cooler 23, and draw out hydrogen chloride dry gas from the top of the tower and draw out the 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 rectify 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 extracted 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 port at the top of the stripping tower 25; the discharge port at the top of the stripping tower 25 is connected to the feed port at the bottom of the recovery tower 28 via the first compressor 26 and the second cooler 27 in sequence; the discharge port at the top of the recovery tower 28 is connected to the first condenser 30 and the middle feed port of the light removal tower 31 respectively via the second compressor 29; The high-pressure light removal unit includes a light removal tower 31, a second condenser 32 and a second reboiler 33; The light-removing tower 31 is used to rectify the high-pressure gas obtained from the second compressor 29 and to draw out the hydrogen chloride gas containing light components from the top of the tower, and to use part of the kettle liquid extracted from the bottom of the tower as the product chemical-grade hydrogen chloride A, and the other part as the feed of the refining tower 34; the second condenser 32 is used to condense the light components extracted from the top of the light-removing tower 31; the second reboiler 33 is used to partially vaporize the heavy components extracted from the bottom of the light-removing tower 31, so that the obtained vapor phase is used as the rising vapor phase of the bottom of the light-removing tower 31, and the liquid phase enters the refining tower 34 for further refining; The discharge port at the top of the light-removing tower 31 is connected to the feed port at the top of the light-removing tower 31 via the second condenser 32; the discharge port at the bottom of the light-removing tower 31 is connected to the feed port at the bottom of the light-removing tower 31 and the middle feed port of the refining tower 34 respectively after passing through 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 rectify part of the bottom liquid of the light removal tower 31, and 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 after being liquefied by the third condenser 35. The bottom liquid is partially vaporized by the third reboiler 36, and the vapor phase part is used as vapor phase reflux, and the liquid phase part is the heavy component, which is extracted as chemical grade hydrogen chloride B; The third condenser 35 is used to condense the light components extracted from the top of the refining tower 34; the third reboiler 36 is used to partially vaporize the heavy components extracted 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 component, which is extracted as chemical grade hydrogen chloride B; 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 .

[0025] According to the system for producing electronic grade hydrogen chloride and co-producing chemical grade hydrogen chloride and industrial grade hydrogen chloride provided by the present invention, the system is also provided with a mother liquor pipeline, a by-product pipeline and an emptying pipeline, wherein the mother liquor pipeline is connected to the bottom discharge port of the stripping tower 25, and is used to return the bottom liquid extracted from the bottom of the stripping tower 25 as the mother liquor to the chlorobenzene production system; the by-product pipeline is connected to the top discharge port of the light removal tower 31, and is used to absorb the light component-containing logistics from the top of the light removal tower 31 with water to obtain by-product hydrochloric acid; the emptying pipeline is connected to the bottom of the recovery tower 28 to process the substances accumulated during the distillation process.

[0026] In the present invention, all equipment can be made of stainless steel, and all standard equipment or general machinery can be used, which greatly reduces the equipment investment cost.

[0027] As a preferred embodiment of the present invention, the method of producing electronic grade hydrogen chloride and co-producing chemical grade hydrogen chloride and industrial grade hydrogen chloride using the above system comprises: Tail gas low temperature recovery unit: After cooling down in the first cooler 23, the chlorobenzene tail gas directly enters the top of the stripping tower 25. The top of the tower is operated at a low temperature. The gas discharged from the top of the tower is a dry gas without mother liquid volatiles, mainly composed of hydrogen chloride and light components, which can be compressed to more than 1.0 MPa by the membrane compressor of the first compressor 26 to obtain a first high-pressure gas. After the first high-pressure gas enters the second cooler 27 for cooling, it is used as the feed of the recovery tower 28 and the heat source of the tower bottom. The bottom liquid of the recovery tower 28 is a high-pressure liquid, which is used as the reflux liquid of the stripping tower 25 after throttling expansion. The gas discharged from the top of the tower is a dry gas without mother liquid volatiles, mainly composed of hydrogen chloride and light components, which can be compressed to more than 4.0 MPa by the membrane compressor as the second compressor 29 to obtain a second high-pressure gas. Part of the second high-pressure gas is used as the feed of the light removal tower 31, and part is processed by the first condenser 30. The condensed liquid part is used as the industrial-grade hydrogen chloride product, and part is used as the top reflux liquid of the recovery tower 28 after throttling expansion.

[0028] High-pressure light-removal unit: the second high-pressure gas portion enters the light-removal tower 31 for distillation treatment and hydrogen chloride gas containing light components is drawn out from the top of the tower, and part of the kettle liquid extracted from the bottom of the tower is used as the product chemical-grade hydrogen chloride A, and the other part is used as the feed of the refining tower 34; the second condenser 32 is used to condense the light components extracted from the top of the light-removal tower 31; the second reboiler 33 is used to vaporize part of the heavy components extracted from the bottom of the light-removal tower 31, so that the obtained vapor phase is used as the rising vapor phase of the bottom of the light-removal tower 31, part of the heavy components is used as chemical-grade hydrogen chloride A, and part of the heavy components enters the refining tower 34 for further refining.

[0029] Product refining unit: 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. Part of the bottom liquid is vaporized by the third reboiler 36 as vapor phase reflux, and part of the bottom liquid is heavy components, which are produced as chemical grade hydrogen chloride B.

[0030] Based on this, the technical solution of the present invention has the following advantages: The method and system for producing electronic-grade hydrogen chloride and co-producing chemical-grade hydrogen chloride and industrial-grade hydrogen chloride provided by the present invention optimizes the process flow, uses chlorobenzene tail gas as a raw material to produce electronic hydrogen chloride, chemical-grade hydrogen chloride and industrial-grade hydrogen chloride, forms a green and environmentally friendly circular economy, and has low equipment investment cost, low process production cost and broad market prospects. In the production process of the present invention, there is no discharge of three wastes, and the recovered mother liquor is returned to the chlorobenzene production system; the recovery rate of the main products electronic 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 byproduct hydrochloric acid, and the discharged light components are nitrogen, oxygen and carbon dioxide, which are pollution-free to the environment, and the chlorobenzene tail gas can be fully recycled. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 This is a schematic diagram of the system flow for producing electronic grade hydrogen chloride and co-producing chemical grade hydrogen chloride and industrial grade hydrogen chloride provided in Example 1 of the present invention.

[0033] Reference numerals: 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 removal tower feed; 11: Light removal tower bottom discharge; 12: Chemical grade hydrogen chloride A; 13: Light removal tower top discharge; 14: Light removal tower discharge light components; 15: Light removal tower reflux; 16: Refining tower feed; 17: Refining tower bottom liquid; 18: Refining tower discharge heavy components (chemical Electronic grade hydrogen chloride B); 19: refining tower kettle reflux; 20: refining tower top discharge; 21: electronic grade hydrogen chloride; 22: refining tower top reflux; 23: first cooler; 24: first reboiler; 25: stripping tower; 26: first compressor; 27: second cooler; 28: recovery tower; 29: second compressor; 30: first condenser; 31: light removal tower; 32: second condenser; 33: second reboiler; 34: refining tower; 35: third condenser; 36: third reboiler; 37: exhaust line. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so as to describe the embodiments of the present invention described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0036] Unless otherwise specified, the various 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.

[0037] In the following examples, the raw gas is tail gas from the chlorobenzene production process, and its composition is shown in Table 1: Mass flow rate: 2000 kg / h; temperature: 20℃; pressure: 0.1MPa; phase: gas phase.

[0038] Table 1 Composition of tail gas from chlorobenzene production process

[0039] Example 1 This embodiment provides a system for producing electronic grade hydrogen chloride and co-producing chemical grade hydrogen chloride and industrial grade hydrogen chloride. The process flow chart of the system is as follows: Figure 1 As shown, it includes: tail gas low temperature recovery unit, high pressure light removal unit and product refining unit; The tail gas low temperature 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 the tail gas to obtain a 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 from the top of the tower (i.e., the stripping tower top discharge 3), and draw out the bottom liquid from the bottom of the tower (i.e., the stripping tower bottom discharge liquid (mother liquor) 2); 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 a light-removal tower feed 10; the recovery tower 28 The first high-pressure gas from the second cooler 27 is distilled and the hydrogen chloride gas is drawn out from the top of the tower (i.e., the recovery tower top discharge 7), and the kettle liquid drawn out from the bottom of the tower (i.e., the recovery tower kettle 6) is used as the reflux liquid of the stripping tower 25 (i.e., the stripping tower reflux 4); the second compressor 29 is used to pressurize the hydrogen chloride gas drawn out from the top of the recovery tower 28 to obtain the second high-pressure gas (i.e., the lightness removal tower feed 10); the first condenser 30 is used to condense part of the second high-pressure gas to obtain the liquid phase part 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 tower (i.e., the recovery tower reflux 8).

[0040] The first cooler 23 is connected to the feed port at the top of the stripping tower 25; the discharge port at the top of the stripping tower 25 is connected to the feed port at the bottom of the recovery tower 28 via the first compressor 26 and the second cooler 27 in sequence; the discharge port at the top of the recovery tower 28 is connected to the first condenser 30 and the middle feed port of the light removal tower 31 respectively via the second compressor 29; The high-pressure light removal unit includes a light removal tower 31, a second condenser 32 and a second reboiler 33; The light-removing tower 31 is used to rectify 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 light-removing tower top discharge 13), and use the kettle liquid part (i.e., the light-removing tower bottom discharge liquid 11) taken out from the bottom of the tower as the product chemical grade hydrogen chloride A (chemical grade hydrogen chloride A 12), and the other part as the feed of the refining tower 34 (i.e., the refining tower feed 16); the second condenser 32 is used to condense part of the light components (i.e., the logistics 13) taken out from the top of the light-removing tower 31 (to obtain the light-removing tower reflux logistics 15); the second reboiler 33 is used to partially vaporize the heavy components taken out from the bottom of the light-removing tower 31, so that the obtained vapor phase is used as the rising vapor phase of the bottom of the light-removing tower 31, and the liquid phase enters the refining tower 34 for further refining; The discharge port at the top of the light-removing tower 31 is connected to the feed port at the top of the light-removing tower 31 via the second condenser 32; the discharge port at the bottom of the light-removing tower 31 is connected to the feed port at the bottom of the light-removing tower 31 and the middle feed port of the refining tower 34 respectively after passing through 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 rectify part of the bottom liquid of the light removal tower 31. The light components (i.e., logistics 20) taken out from the top of the tower are liquefied by the third condenser 35 and part of them are used as electronic grade hydrogen chloride products (i.e., logistics 21) and part of them are used as reflux liquid of the refining tower 34 (i.e., logistics 22). The bottom liquid (i.e., logistics 17) is partially vaporized by the third reboiler 36, the vapor phase part is used as vapor phase reflux (i.e., logistics 19), and the liquid phase part is taken out as heavy components (chemical grade hydrogen chloride B) (i.e., logistics 18); the third condenser 35 is used to condense the light components taken out from the top of the refining tower 34; the third reboiler 36 is used to partially vaporize the heavy components taken out 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 taken out as the heavy components (chemical grade hydrogen chloride B); 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 .

[0041] According to the system for producing electronic-grade hydrogen chloride and co-producing chemical-grade hydrogen chloride and industrial-grade hydrogen chloride provided by the present invention, the system is also provided with a mother liquor pipeline and a by-product pipeline, wherein the mother liquor pipeline is connected to the bottom discharge port of the stripping tower 25, and is used to return the bottom liquid extracted from the bottom of the stripping tower 25 as the mother liquor to the chlorobenzene production system; the by-product pipeline is respectively connected to the top discharge port of the light-removal tower 31, and is used to absorb the logistics containing light components from the top of the light-removal tower 31 with water to obtain the by-product hydrochloric acid.

[0042] As a preferred embodiment of the present invention, the method for producing electronic grade hydrogen chloride and co-producing chemical grade hydrogen chloride and industrial grade hydrogen chloride comprises the following steps: Low-temperature recovery of tail gas: After cooling down in the first cooler 23, the chlorobenzene tail gas directly enters the top of the stripping tower 25. The top of the tower is operated at a low temperature. The gas discharged from the top of the tower is a dry gas without volatile components of the mother liquid, mainly composed of hydrogen chloride and light components, which can be compressed to more than 1.0 MPa by the membrane compressor of the first compressor 26 to obtain a first high-pressure gas. After the first high-pressure gas enters the second cooler 27 for cooling, it is used as the feed of the recovery tower 28 and the heat source of the tower bottom. The bottom liquid of the recovery tower 28 is a high-pressure liquid, which is used as the reflux liquid of the stripping tower 25 after throttling expansion. The gas discharged from the top of the tower is a dry gas without volatile components of the mother liquid, mainly composed of hydrogen chloride and light components, which can be compressed to more than 4.0 MPa by the membrane compressor as the second compressor 29 to obtain a second high-pressure gas. Part of the second high-pressure gas is used as the feed of the light removal tower 31, and part is processed by the first condenser 30. The condensed liquid part is used as the industrial-grade hydrogen chloride product, and part is used as the top reflux liquid of the recovery tower 28 after throttling expansion.

[0043] High-pressure light-removal part: the second high-pressure gas part enters the light-removal tower 31 for distillation treatment and draws out hydrogen chloride gas containing light components from the top of the tower, and uses part of the kettle liquid extracted from the bottom of the tower as the product chemical-grade hydrogen chloride A, and the other part as the feed of the refining tower 34; the second condenser 32 is used to condense the light components extracted from the top of the light-removal tower 31; the second reboiler 33 is used to vaporize part of the heavy components extracted from the bottom of the light-removal tower 31, so that the obtained vapor phase is used as the rising vapor phase of the bottom of the light-removal tower 31, part of the heavy components is used as chemical-grade hydrogen chloride A, and part of the heavy components enters the refining tower 34 for further refining.

[0044] Product refining part: the refining tower 34 is used to distill part of the bottom liquid of the light removal tower 31. After liquefaction through 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 through the third reboiler 36 as vapor phase reflux, and part of the bottom liquid is extracted as heavy component (chemical grade hydrogen chloride B).

[0045] Among them, the vapor phase feed pressure of the stripping tower is about 0.12MPa, and the temperature is about 10°C; the pressure of the bottom discharge liquid of the stripping tower is about 0.12MPa, and the temperature is about 30°C; the pressure of the top exhaust of the stripping tower is about 0.12MPa, and the temperature is about -85°C; the pressure of the top reflux of the stripping tower is about 0.12MPa, and the temperature is about -85°C; the reflux ratio is 0.5.

[0046] The feed pressure of the recovery tower is about 0.18MPa and the temperature is about 55°C; the pressure of the produced liquid at the bottom of the recovery tower is about 0.18MPa and the temperature is about -30°C; the pressure of the exhaust gas at the top of the recovery tower is about 0.18MPa and the temperature is about -30°C; the pressure of the reflux at the top of the recovery tower is about 0.18MPa and the temperature is about -30°C; the reflux ratio is 0.5.

[0047] The feed pressure of the light-removal tower is about 4.2 MPa and the temperature is about 20°C; the pressure of the bottom produced liquid of the light-removal tower is about 4.2 MPa and the temperature is about 20°C; the pressure of the top exhaust gas of the light-removal tower is about 4.2 MPa and the temperature is about 20°C; the pressure of the top reflux of the light-removal tower is about 4.2 MPa and the temperature is about 20°C; the reflux ratio is 9.

[0048] The feed pressure of the refining tower is about 4.2MPa and the temperature is about 20°C; the pressure of the bottom produced liquid of the refining tower is about 4.2MPa and the temperature is about 20°C; the pressure of the top exhaust of the refining tower is about 4.2MPa and the temperature is about 20°C; the pressure of the top reflux of the refining tower is about 4.2MPa and the temperature is about 20°C; the reflux ratio is 2.

[0049] Feed the raw gas into Figure 1 The system shown in the figure is processed by the above method, and the operating process data is 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.

[0050] Table 2

[0051] When the continuous distillation conditions are controlled within the preferred range defined by the present invention, a technical effect equivalent to that of Example 1 can be obtained, that is, electronic hydrogen chloride can be produced while co-producing industrial-grade hydrogen chloride and chemical-grade hydrogen chloride.

[0052] Example 2 This embodiment provides a method for producing electronic grade hydrogen chloride and co-producing chemical grade hydrogen chloride and industrial grade hydrogen chloride. The only difference between this method and embodiment 1 is that the reflux ratio of the lightness removal tower is 5.

[0053] The operating 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, and the electronic-grade hydrogen chloride product will not meet the electronic-grade hydrogen chloride concentration requirements of the national standard.

[0054] Table 3

[0055] Example 3 This embodiment provides a method for producing electronic grade hydrogen chloride and co-producing chemical grade hydrogen chloride and industrial grade hydrogen chloride, which is different from Embodiment 1 only in that the top operating pressure of the lightness removal tower is 6 MPa.

[0056] The operating process data are shown in Table 4. The results show that when the pressure of the lightness removal tower increases to 6MPa, the carbon dioxide content of the chemical grade hydrogen chloride and electronic grade hydrogen chloride products increases, among which the electronic grade hydrogen chloride product will not meet the electronic grade hydrogen chloride concentration requirement of the national standard.

[0057] Table 4

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions 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 co-producing chemical grade hydrogen chloride and industrial grade hydrogen chloride, characterized in that: include: The tail gas emitted from the industrial production of chlorobenzene is introduced into a stripping tower as a raw material, and the gas produced from the top of the stripping tower is compressed to obtain a first high-pressure gas; Passing the first high-pressure gas into a recovery tower, and compressing the gas produced from the top of the recovery tower to obtain a second high-pressure gas; Passing a portion of the second high-pressure gas into a light-removal tower, and condensing another portion of the second high-pressure gas to obtain an industrial-grade hydrogen chloride product; A portion of the lightness removal tower bottom liquid is extracted as a chemical grade hydrogen chloride product A, another portion of the lightness removal tower bottom liquid is partially vaporized, the obtained vapor phase is used as the rising vapor phase of the lightness removal tower bottom, the obtained liquid phase enters a refining tower for further refining, an electronic grade hydrogen chloride product is extracted from the top of the refining tower, and a heavy component is extracted from the refining tower bottom as a chemical grade hydrogen chloride product B; The tail gas composition includes hydrogen chloride, chlorine, organic gas, nitrogen, oxygen, carbon dioxide and water.

2. The method for producing electronic grade hydrogen chloride and co-producing chemical grade hydrogen chloride and industrial grade hydrogen chloride according to claim 1, characterized in that: In terms of molar content, the tail gas composition includes: HCl not less than 90%, Cl2 not higher than 0.5%, organic gas content not higher than 0.5%, and the content of other components is 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%.

3. The method for producing electronic grade hydrogen chloride and co-producing chemical grade hydrogen chloride and industrial grade hydrogen chloride according to claim 1 or 2, characterized in that: The water content in the recovery tower feed is less than 0.001% by molar content; and / or, in terms of molar content, the content of chlorine and organic gas in the lightness removal tower feed is less than 0.00001%; And / or, in terms of molar content, the carbon dioxide content in the feed to the refining tower is less than 0.00004%.

4. The method for producing electronic grade hydrogen chloride and co-producing chemical grade hydrogen chloride and industrial grade hydrogen chloride according to any one of claims 1 to 3, characterized in that: The operating conditions for controlling the lightness removal tower include: the top operating pressure is 3.9~4.5MPa, the top operating temperature is 15~30℃, and the reflux ratio is 8~12.

5. The method for producing electronic grade hydrogen chloride and co-producing chemical grade hydrogen chloride and industrial grade hydrogen chloride according to any one of claims 1 to 4, characterized in that: The feed pressure of the light-removal tower is 3.9~4.5MPa, and the feed temperature is 15~30°C; the pressure of the bottom produced liquid of the light-removal tower is 3.9~4.5MPa, and the temperature of the bottom produced liquid is 15~30°C; the pressure of the top exhaust gas of the light-removal tower is 3.9~4.5MPa, and the temperature of the top exhaust gas is 15~30°C; the pressure of the top reflux of the light-removal tower is 3.9~4.5MPa, and the temperature of the top reflux is 15~30°C.

6. The method for producing electronic grade hydrogen chloride and co-producing chemical grade hydrogen chloride and industrial grade hydrogen chloride according to any one of claims 1 to 5, characterized in that: The operating conditions for controlling the stripping tower include: the top operating pressure is 0.07~0.17MPa, the top operating temperature is -90~-75℃, and the reflux ratio is 0.4~1.

7. The method for producing electronic grade hydrogen chloride and co-producing chemical grade hydrogen chloride and industrial grade hydrogen chloride according to any one of claims 1 to 6, characterized in that: The pressure of the vapor phase feed of the stripping tower is 0.07~0.17MPa, and the temperature of the vapor phase feed is 0~10℃; the pressure of the bottom discharge liquid of the stripping tower is 0.07~0.17MPa, and the temperature of the bottom discharge liquid is 25~40℃; the pressure of the top exhaust of the stripping tower is 0.07~0.17MPa, and the temperature of the top exhaust is -90~-75℃; the pressure of the top reflux of the stripping tower is 0.07~0.17MPa, and the temperature of the top reflux is -90~-75℃.

8. The method for producing electronic grade hydrogen chloride and co-producing chemical grade hydrogen chloride and industrial grade hydrogen chloride according to any one of claims 1 to 7, characterized in that: The feed pressure of the recovery tower is 0.08~0.18MPa, and the feed temperature is 35~55°C; the bottom produced liquid pressure of the recovery tower is 0.08~0.18MPa, and the bottom produced liquid temperature is -35~-20°C; the top exhaust pressure of the recovery tower is 0.08~0.18MPa, and the top exhaust temperature is -35~-20°C; the top reflux pressure of the recovery tower is 0.08~0.18MPa, and the top reflux temperature is -35~-20°C; The reflux ratio is 0.4~1; And / or, the feed pressure of the refining tower is 3.9~4.9MPa, and the feed temperature is 15~30℃; the bottom produced liquid pressure of the refining tower is 3.9~4.9MPa, and the bottom produced liquid temperature is 15~30℃; the top exhaust pressure of the refining tower is 3.9~4.9MPa, and the top exhaust temperature is 15~30℃; the top reflux pressure of the refining tower is 3.9~4.9MPa, and the top reflux temperature is 15~30℃; the reflux ratio is 2~5.

9. The method for producing electronic grade hydrogen chloride and co-producing chemical grade hydrogen chloride and industrial grade hydrogen chloride according to any one of claims 1 to 8, characterized in that: include: The tail gas emitted from the industrial production of chlorobenzene is introduced into the top of the stripping tower as a raw material, and 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, the kettle liquid of the recovery tower is throttled and expanded and then refluxed to the stripping tower, and the light component at the top of the recovery tower is compressed to obtain the second high-pressure gas; Passing a portion of the second high-pressure gas into a light-removing tower, and condensing another portion of the second high-pressure gas to obtain a high-pressure liquid; a portion of the high-pressure liquid is refluxed to the top of the recovery tower, and another portion of the high-pressure liquid is used as the industrial-grade hydrogen chloride product; Directly discharging a portion of the light components at the top of the light-removal tower for recovery, and condensing another portion of the light components at the top of the light-removal tower and then refluxing to the light-removal tower; A portion of the liquid in the bottom of the lightness removal tower is extracted as chemical grade hydrogen chloride product A, and another portion of the liquid in the bottom of the lightness removal tower is partially vaporized, and the obtained vapor phase is used as the rising vapor phase of the bottom of the lightness removal tower, and the obtained liquid phase enters the refining tower for further refining. A portion of the light components at the top of the refining tower is condensed and directly recovered to obtain electronic grade hydrogen chloride, and the other portion is refluxed to the refining tower; A portion of the refining tower bottom liquid is directly recovered, and the other portion is partially vaporized. The obtained vapor phase is used as the rising vapor phase of the refining tower bottom, and the obtained liquid phase is the heavy component, which is recovered as chemical grade hydrogen chloride B.

10. A system for producing electronic grade hydrogen chloride and co-producing chemical grade hydrogen chloride and industrial grade hydrogen chloride, characterized in that: include: Tail gas low temperature recovery unit, high pressure light removal unit and product refining unit; The tail gas low temperature recovery unit comprises 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 down the tail gas; the stripping tower (25) is used to distill the cooled tail gas from the first cooler (23), and to draw out hydrogen chloride dry gas from the top of the tower and tower bottom liquid from the bottom of the tower; the first reboiler (24) is used to vaporize part of the tower 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 reboil the light components at the top of the stripping tower (25) to obtain a first high-pressure 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 kettle liquid drawn out 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 out 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 port at the top of the stripping tower (25); the discharge port at the top of the stripping tower (25) is connected to the feed port at the bottom of the recovery tower (28) via the first compressor (26) and the second cooler (27) in sequence; the discharge port at the top of the recovery tower (28) is connected to the middle feed ports of the first condenser (30) and the lightness removal tower (31) respectively after passing through the second compressor (29); The high-pressure light removal unit comprises a light removal tower (31), a second condenser (32) and a second reboiler (33); The light-removing tower (31) is used to rectify the high-pressure gas obtained from the second compressor (29) and to draw out hydrogen chloride gas containing light components from the top of the tower, and to use part of the kettle liquid extracted from the bottom of the tower as the product chemical-grade hydrogen chloride A, and the other part as the feed of the refining tower (34); the second condenser (32) is used to condense the light components extracted from the top of the light-removing tower (31); the second reboiler (33) is used to partially vaporize the heavy components extracted from the bottom of the light-removing tower (31), so that the obtained vapor phase is used as the rising vapor phase of the bottom of the light-removing tower (31), and the liquid phase enters the refining tower (34) for further refining; The discharge port at the top of the light-removal tower (31) is connected to the feed port at the top of the light-removal tower (31) via the second condenser (32); the discharge port at the bottom of the light-removal tower (31) is connected to the feed port at the bottom of the light-removal tower (31) and the feed port in the middle of the refining tower (34) via the second reboiler (33); The product refining unit comprises a refining tower (34), a third condenser (35) and a third reboiler (36); The refining tower (34) is used to carry out rectification treatment on 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 part is used as vapor phase reflux, and the liquid phase part is a heavy component, which is produced as chemical grade hydrogen chloride B; The third condenser (35) is used to condense the light components extracted from the top of the refining tower (34); the third reboiler (36) is used to partially vaporize the heavy components extracted 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 extracted as chemical grade hydrogen chloride B; 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 a 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 a third reboiler (36); Preferably, the system is further provided with a mother liquor pipeline and a by-product pipeline, wherein the mother liquor pipeline is connected to the bottom discharge port of the stripping tower (25) for returning the bottom liquid taken out from the bottom of the stripping tower (25) as the mother liquor to the chlorobenzene production system; and the by-product pipeline is connected to the top discharge port of the light-removal tower (31) for absorbing the light component-containing stream from the top of the light-removal tower (31) with water and then delivering it as a hydrochloric acid product.

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