Energy-saving high-purity hydrogen chloride production process system

Abstract

The utility model belongs to the field of hydrogen chloride purification, and relates to an energy-saving high-purity hydrogen chloride production process system which comprises a light component removal tower, a product tower, a refrigeration compressor, an oil separator, a refrigerant storage tank, a refrigerant cooler, a cooling liquid circulating pump, a secondary refrigerant heat exchanger and a secondary refrigerant circulating pump, a light component removal tower condenser is arranged at the top of the light component removal tower, a light component removal tower reboiler is arranged at the bottom of the light component removal tower, and the hydrogen chloride extraction port at the bottom of the light component removal tower is connected to an inlet of the product tower through a pipeline; a product tower condenser is arranged at the top of the product tower, and a product tower reboiler is arranged at the bottom of the product tower. By optimizing the heat exchange network and combining the refrigeration compressor with the rectification system, the combined cooling and heating is realized, the low-grade heat is fully utilized, and the cooling capacity of the tower kettle is recovered, so that the consumption of circulating water is saved, the steam consumption and the power consumption of the whole device are saved, and the purposes of energy conservation and consumption reduction are achieved.

Description

Technical Field

[0001] The utility model belongs to the field of hydrogen chloride purification, in particular to an energy-saving high-purity hydrogen chloride production process system. Background Technique

[0002] A large amount of by-product hydrogen chloride gas produced by chlor-alkali plants has many impurities and low purity. It is a cheap and difficult-to-treat gas, often used to make hydrochloric acid, with low added value and poor economic benefits. High-purity hydrogen chloride is an important electronic special gas material, widely used in fields such as semiconductor integrated circuits, photovoltaic, and metal smelting. It is expensive and has very good economic value. With the rapid development of the large-scale integrated circuit and solar photovoltaic industries, the demand for electronic-grade hydrogen chloride is also increasing rapidly, and the industry has broad development space.

[0003] As an electronic special gas material, in the production of high-purity hydrogen chloride, the requirements for the content of impurities such as THC, H 2 0 and metal ions in hydrogen chloride are getting lower and lower, and need to be removed to the PPM level. Therefore, it requires higher difficulty and energy consumption.

[0004] Chinese Patent CN114634163A discloses a production device and method for manufacturing electronic-grade hydrogen chloride. The device includes an adsorption tower, a cooler, a raw material rectification tower, a first deweight tower, a flash tank, a reactor, a de-light tower, a mobile tower, a second deweight tower, and a membrane separation device.

[0005] Chinese Patent CN112678776A discloses a rectification and purification method for electronic-grade hydrogen chloride. A rectification and purification device is used for rectifying and purifying hydrogen chloride. The rectification and purification device includes a raw material supply pipeline, a hydrogen chloride rectification system, and a hydrogen chloride product filling device connected in sequence. The hydrogen chloride rectification system includes a first rectification tower and a second rectification tower connected in sequence. After the raw material supply pipeline enters the first rectification tower to separate heavy components, the obtained light components enter the second rectification tower for light component separation to obtain rectified hydrogen chloride.

[0006] Chinese Patent CN110255501A discloses a method for preparing electronic-grade high-purity hydrogen chloride, which comprises the following steps: S1. Collect the by-product hydrogen chloride generated during the production of chlorotoluene as the raw material gas source and enter S2; S2. Pass the raw material gas into a dryer to remove the moisture in the raw material gas and enter S3; S3. Pass the raw material gas after removing moisture into a light-removing rectification column to obtain the bottom product A and the top product A with a boiling point lower than that of hydrogen chloride and enter S4; S4. Pass the bottom product A into a heavy-removing rectification column to obtain the top product B, the reflux liquid and the bottom product B with a boiling point higher than that of hydrogen chloride and enter S5; S5. Collect a part of the reflux liquid as the target product for storage, pass the bottom product B into a recovery rectification column to obtain the third top product and the third bottom product with a boiling point higher than that of hydrogen chloride and enter S6; S6. Collect the third top product as the raw material gas source and return to S2.

[0007] The existing high-purity hydrogen chloride process mainly relies on rectification to produce, with a complex process flow, many equipment pipelines and valves, a relatively high equipment investment cost, and a relatively high possibility of pollution during the production process; at the same time, the energy consumption is high during the low-temperature rectification process, resulting in an increase in operating costs. Summary of the Invention

[0008] The purpose of the present invention is to overcome the deficiencies of the prior art and provide an energy-saving high-purity hydrogen chloride production process system. By optimizing the heat exchange network and combining the refrigeration compressor with the rectification system, combined heat and power production is realized to achieve the purpose of energy conservation and consumption reduction.

[0009] The technical solution adopted by the present invention to solve the technical problems is:

[0010] An energy-saving high-purity hydrogen chloride production process system includes a light component removal tower, a product tower, a refrigeration compressor, an oil separator, a refrigerant storage tank, a refrigerant cooler, and a coolant circulation pump. The light component removal tower has a hydrogen chloride raw material inlet, a hydrogen chloride extraction outlet at the bottom, a light component removal tower condenser at the top of the tower, and a light component removal tower reboiler at the bottom of the tower. The hydrogen chloride extraction outlet at the bottom of the light component removal tower is connected to the inlet of the product tower through a pipeline. The product tower has a product tower condenser at the top and a product tower reboiler at the bottom. The refrigerant channel of the refrigeration compressor is a closed cycle. The outlet of the refrigeration compressor is connected to the inlet of the oil separator through a pipeline. The oil outlet of the oil separator is connected to the return port of the compressor through a pipeline. The gas phase outlet of the oil separator is connected to the tube side inlet of the refrigerant cooler through a pipeline. The shell side outlet pipeline of the refrigerant cooler is divided into two paths. One path is connected to the shell side inlet of the light component removal tower reboiler, and the other path is connected to the shell side inlet of the product tower reboiler. The shell side outlets of the light component removal tower reboiler and the product tower reboiler are both connected to the shell side inlet of the refrigerant cooler through the coolant circulation pump. The tube side outlet of the refrigerant cooler is connected to the inlet of the refrigerant storage tank. The outlet pipeline of the refrigerant storage tank is divided into two paths. One path is connected to the inlet of the light component removal tower condenser, and the other path is connected to the inlet of the product tower condenser. The outlet pipelines of the light component removal tower condenser and the product tower condenser are both connected to the inlet of the refrigeration compressor.

[0011] Further, a first throttle valve and a second throttle valve are respectively arranged on the inlet pipelines of the light component removal tower condenser and the product tower condenser.

[0012] The energy-saving high-purity hydrogen chloride production process system further includes a secondary coolant heat exchanger and a secondary coolant circulation pump. The outlet pipeline of the refrigerant storage tank is connected to the inlet of the secondary coolant heat exchanger. The shell side outlet pipeline of the secondary coolant heat exchanger is divided into two paths. One path is connected to the inlet of the light component removal tower condenser, and the other path is connected to the inlet of the product tower condenser. The outlet pipelines of the light component removal tower condenser and the product tower condenser are both connected to the shell side inlet of the secondary coolant heat exchanger through the secondary coolant circulation pump. The outlet of the secondary coolant heat exchanger is connected to the inlet of the refrigeration compressor through a pipeline.

[0013] Further, a third throttle valve is arranged on the inlet pipeline of the secondary coolant heat exchanger.

[0014] Further, both the light component removal tower and the product tower adopt internal reflux for reflux.

[0015] Further, there is a light component extraction outlet at the top of the light component removal tower.

[0016] Further, the bottom extraction pipeline of the light component removal tower is connected to the tube side inlet of the light component removal tower reboiler, and the tube side outlet of the light component removal tower reboiler is connected to the bottom reflux port of the light component removal tower through a pipeline.

[0017] Furthermore, the top of the product column is provided with a light component extraction outlet, the side line is provided with a high-purity hydrogen chloride product extraction outlet, and the bottom of the column is provided with a heavy component extraction outlet.

[0018] Furthermore, the compressor is a screw compressor, a piston compressor or a centrifugal compressor.

[0019] Furthermore, the refrigerant is one of chlorodifluoromethane (R22), R507, propane (R290), ammonia (R717). R507 is azeotropic refrigerant mixture composed of difluoromethane (R32) and pentafluoroethane (R125).

[0020] Furthermore, the secondary refrigerant is one of dichloromethane, low-temperature silicone oil at -60°C, and ethanol.

[0021] The advantages and positive effects of the present utility model are as follows:

[0022] 1. The present utility model adopts two-step light component removal in the light removal column and the product column to ensure that the light component content in the product does not exceed the standard. The hydrogen chloride product is extracted from the side line in gaseous phase, which ensures that the heavy components and metal ions in the product do not exceed the standard.

[0023] 2. By optimizing the heat exchange network and combining the refrigeration compressor with the distillation system, the present utility model realizes combined production of heat and cold, and makes full use of low-grade heat. At the same time, the cold energy at the bottom of the column is recovered, which not only saves the consumption of circulating water, but also saves the steam consumption and power consumption of the entire device, achieving the purpose of energy conservation and consumption reduction.

[0024] 3. The present utility model has low energy consumption, reasonable design, high product purity and low investment. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural diagram of an energy-saving high-purity hydrogen chloride production process system according to Embodiment 1 of the present utility model;

[0026] Figure 2 It is a structural diagram of an energy-saving high-purity hydrogen chloride production process system according to Embodiment 2 of the present utility model.

[0027] 1 - Refrigeration compressor; 2 - Oil separator; 3 - Refrigerant cooler; 4 - Refrigerant storage tank; 5 - Coolant circulation pump; 6 - Light removal column; 7 - Light removal column condenser; 8 - Light removal column reboiler; 9 - Product column; 10 - Product column condenser; 11 - Product column reboiler; 12 - Secondary refrigerant circulation pump; 13 - Secondary refrigerant heat exchanger; 14 - First throttle valve, 15 - Second throttle valve, 16 - Third throttle valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The present utility model will be further described in detail through specific embodiments below. The following embodiments are only descriptive and not restrictive, and the protection scope of the present utility model cannot be limited thereby.

[0029] Embodiment 1

[0030] As Figure 1 shown, an energy-saving high-purity hydrogen chloride production process system includes a light component removal tower 6, a product tower 9, a refrigeration compressor 1, an oil separator 2, a refrigerant storage tank 4, a refrigerant cooler 3, and a coolant circulation pump 5.

[0031] The light component removal tower 6 has a hydrogen chloride raw material inlet, a hydrogen chloride extraction outlet at the bottom, a light component removal tower condenser 7 is provided at the top of the light component removal tower 6, and a light component removal tower reboiler 8 is provided at the bottom.

[0032] The hydrogen chloride raw material (the raw material includes the following components by volume fraction: HCl: 94% - 95%, H 2 : 5%, H 2 O: 100 ppm, CO 2 : 1000 ppm, CO: 100 ppm, CH 4 +C 2 H 2 : 100 ppm, N 2 : 100 ppm, O 2 +Ar: 100 ppm) from the chlor-alkali plant after pretreatment enters the upper part of the light component removal tower 6. The top pressure of the light component removal tower 6 is controlled at 1.0 Mpa(G) - 2.5 Mpa(G), and the top temperature is controlled at -35°C - -5°C. After pressurized separation, the light components gather at the top. After the gas phase at the top is condensed by the light component removal tower condenser 7, the liquid phase flows back to the light component removal tower 6 by itself, and the non-condensable gas (including N 2 、H 2 、CH 4 、CO 2 、CO, HCl, etc.) is extracted from the top; the hydrogen chloride containing heavy components is extracted from the bottom.

[0033] The pipeline for extracting from the bottom of the light component removal tower 6 is connected to the inlet of the tube side of the light component removal tower reboiler 8, and the outlet of the tube side of the light component removal tower reboiler 8 is connected to the bottom reflux port of the light component removal tower 6 through a pipeline.

[0034] The top of the product tower 9 has a light component extraction outlet, the side line has a high-purity hydrogen chloride product extraction outlet, and the bottom has a heavy component extraction outlet.

[0035] The hydrogen chloride containing heavy components at the bottom of the light removal tower 6 enters the product tower 9 through a pipeline. The top pressure of the product tower 9 is controlled at 0.8 Mpa(G) to 2.3 Mpa(G), and the top temperature is controlled at -38 °C to -7 °C. After pressurized separation, further light removal treatment is carried out at the top to remove the light components brought from the bottom of the light removal tower 6, and heavy components such as water, oil, and metal ions are removed from the bottom of the tower. The gas phase at the top of the product tower 9 is condensed by the product tower condenser 10, and the condensed liquid phase flows back to the tower by gravity. The non-condensable gas (including N 2 、H 2 、CH 4 、CO 2 、CO, HCl, etc.) is taken out from the top of the tower; qualified high-purity hydrogen chloride gas-phase products are taken out from the side line of the product tower 9. The volume fractions of each component of the high-purity hydrogen chloride gas-phase product are as follows: HCl > 99.9999%, H 2 <0.01 ppm, H 2 O<0.5 ppm, CO 2 <0.4 ppm, CO<0.01 ppm, CH 4 +C 2 H 2 <0.05 ppm, N 2 <0.01 ppm, O 2 +Ar<0.01 ppm, metal ions (iron, manganese, cobalt, zinc, copper, chromium, nickel)<0.2 mg / L; the bottom of the tower contains hydrogen chloride with water, oil, and heavy metals and flows out of the boundary area by differential pressure.

[0036] The pipeline at the bottom of the product tower 9 is connected to the inlet of the tube side of the product tower reboiler 11, and the outlet of the tube side of the product tower reboiler 11 is connected to the bottom reflux port of the product tower 9 through a pipeline. The refrigeration compressor 1 is a screw compressor, piston compressor, or centrifugal compressor. The refrigerant channel of the refrigeration compressor 1 is a closed cycle. After the low-pressure refrigerant is compressed by the refrigeration compressor 1, the pressure increases to 1.5 Mpa(G) to 2.2 Mpa(G), and the exhaust temperature is 78 °C to 92 °C. Then it enters the oil separator 2 for separation through a pipeline. The outlet of the refrigeration compressor 1 is connected to the inlet of the oil separator 2 through a pipeline. The lubricating oil is connected to the reflux port of the refrigeration compressor 1 through the oil circuit outlet of the oil separator 2 through a pipeline. The gaseous refrigerant enters the refrigerant cooler 3 through a pipeline at the gas-phase outlet of the oil separator 2 and exchanges heat with ethylene glycol from the bottom of the light removal tower 6 at a temperature of 20 °C to 28 °C. The refrigerant is condensed to 40 °C and becomes a liquid, saving the consumption of circulating water. The temperature of the ethylene glycol after heat exchange is 28 °C to 37 °C. After coming out of the shell-side outlet of the refrigerant cooler 3, it is divided into two paths. One path exchanges heat with the light removal tower reboiler 8, and the other path exchanges heat with the product tower reboiler 11. The ethylene glycol after heat exchange is circulated and transported to the shell-side inlet of the refrigerant cooler 3 through the coolant circulation pump 5.

[0037] After heat exchange, the gaseous refrigerant becomes a liquid refrigerant (R22) and enters the refrigerant storage tank 4. After coming out of the outlet of the refrigerant storage tank 4, it passes through the first throttle valve 14 and enters the de-light tower condenser 7, and passes through the second throttle valve 15 and enters the product tower condenser 10, providing cooling capacity for the de-light tower condenser 7 and the product tower condenser 10. After heat exchange, the liquid refrigerant becomes a gas. After the gaseous refrigerant passes through the outlets of the de-light tower condenser 7 and the product tower condenser 10 respectively, it re-enters the refrigeration compressor 1 through the pipeline for pressurization to complete the closed-loop cycle.

[0038] The de-light tower reboiler 8 uses an ethylene glycol aqueous solution as a heat source to provide heat for the bottom of the de-light tower 6. The temperature of the ethylene glycol entering the de-light tower reboiler 8 is between 28°C and 37°C, and the temperature of the ethylene glycol coming out of the de-light tower reboiler 8 is between 20°C and 28°C. The de-light tower condenser 7 uses a liquid refrigerant as a cold source to provide cooling capacity for the top of the tower. The temperature of the liquid refrigerant is between -40°C and -10°C.

[0039] The product tower reboiler 11 uses an ethylene glycol aqueous solution as a heat source to provide heat for the bottom of the product tower 9. The temperature of the ethylene glycol entering the product tower reboiler 11 is between 28°C and 37°C, and the temperature of the ethylene glycol coming out of the product tower reboiler 11 is between 20°C and 28°C. The product tower condenser 10 uses a liquid refrigerant as a cold source to provide cooling capacity for the top of the tower. The temperature of the liquid refrigerant entering the condenser is between -40°C and -10°C.

[0040] Example 2

[0041] As Figure 2 shown in the energy-saving high-purity hydrogen chloride production process system, the difference from Example 1 is that it further includes a secondary refrigerant heat exchanger 13 and a secondary refrigerant circulation pump 12.

[0042] After the liquid refrigerant is throttled by the third throttle valve 16, it enters the secondary refrigerant heat exchanger 13. After heat exchange with the secondary refrigerant returning from the de-light tower condenser 7 and the product tower condenser 10, it re-enters the refrigeration compressor 1 through the pipeline for pressurization to complete the closed-loop cycle. After the heat-exchanged secondary refrigerant comes out of the shell-side outlet of the secondary refrigerant heat exchanger 13, it is divided into two paths. One path enters the de-light tower condenser 7 to provide cooling capacity for it, and the other path enters the product tower condenser 10 to provide cooling capacity for it. After the heat-exchanged secondary refrigerant comes out of the outlets of the de-light tower condenser 7 and the product tower condenser 10, it is circulated and input into the secondary refrigerant heat exchanger 13 through the secondary refrigerant circulation pump 12. The secondary refrigerant is dichloromethane, low-temperature silicone oil at -60°C or ethanol.

[0043] The de-light tower condenser 7 uses a secondary refrigerant as a cold source to provide cooling capacity for the top of the tower. The temperature of the secondary refrigerant entering the condenser is between -40°C and -10°C.

[0044] The product tower condenser 10 uses a secondary refrigerant as a cold source to provide cooling capacity for the top of the tower. The temperature of the secondary refrigerant entering the condenser is between -40°C and -10°C.

[0045] The above are only the preferred embodiments of the present utility model. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the utility model, several modifications and improvements can still be made, and these all belong to the protection scope of the present utility model.

Claims

1. An energy-saving high-purity hydrogen chloride production process system, characterized in that: The invention comprises a light-removal tower (6), a product tower (9), a refrigeration compressor (1), an oil separator (2), a refrigerant storage tank (4), a refrigerant cooler (3) and a coolant circulation pump (5). The light-removal tower (6) has a hydrogen chloride raw material inlet and a hydrogen chloride production outlet at the bottom of the tower. The light-removal tower (6) is provided with a light-removal tower condenser (7) at the top and a light-removal tower reboiler (8) at the bottom. The hydrogen chloride production outlet at the bottom of the light-removal tower (6) is connected to the inlet of the product tower (9) through a pipeline. The product tower (9) is provided with a product tower condenser (10) at the top and a product tower reboiler (11) at the bottom. The refrigerant channel of the refrigeration compressor (1) is a closed cycle. The outlet of the refrigeration compressor (1) is connected to the inlet of the oil separator (2) through a pipeline. The oil outlet of the oil separator (2) is connected to the reflux port of the compressor through a pipeline. ) is connected to the tube-side inlet of the refrigerant cooler (3) through a pipeline. The shell-side outlet pipeline of the refrigerant cooler (3) is divided into two routes, one of which is connected to the shell-side inlet of the de-light tower reboiler (8) and the other is connected to the shell-side inlet of the product tower reboiler (11). The shell-side outlet pipelines of the de-light tower reboiler (8) and the shell-side outlet pipelines of the product tower reboiler (11) both enter the shell-side inlet of the refrigerant cooler (3) after passing through a coolant circulation pump (5). The tube-side outlet of the refrigerant cooler (3) is connected to the inlet of the refrigerant storage tank (4). The outlet pipeline of the refrigerant storage tank (4) is divided into two routes, one of which is connected to the inlet of the de-light tower condenser (7) and the other is connected to the inlet of the product tower condenser (10). The outlet pipelines of the de-light tower condenser (7) and the product tower condenser (10) are both connected to the inlet of the refrigeration compressor (1).

2. The energy-saving high-purity hydrogen chloride production process system according to claim 1 is characterized in that: A first throttle valve (14) and a second throttle valve (15) are respectively arranged on the inlet pipelines of the light removal tower condenser (7) and the product tower condenser (10).

3. The energy-saving high-purity hydrogen chloride production process system according to claim 1 is characterized in that: It also includes a refrigerant heat exchanger (13) and a refrigerant circulation pump (12). The outlet pipeline of the refrigerant storage tank (4) is connected to the inlet of the refrigerant heat exchanger (13). The shell-side outlet pipeline of the refrigerant heat exchanger (13) is divided into two routes, one route is connected to the inlet of the delight tower condenser (7), and the other route is connected to the inlet of the product tower condenser (10). The outlet pipelines of the delight tower condenser (7) and the product tower condenser (10) are both connected to the shell-side inlet of the refrigerant heat exchanger (13) through the refrigerant circulation pump (12); the outlet of the refrigerant heat exchanger (13) is connected to the inlet of the refrigeration compressor (1) through a pipeline.

4. The energy-saving high-purity hydrogen chloride production process system according to claim 3 is characterized in that: A third throttle valve (16) is provided on the inlet pipeline of the refrigerant heat exchanger (13).

5. The energy-saving high-purity hydrogen chloride production process system according to any one of claims 1 to 4, characterized in that: The light-removal tower (6) and the product tower (9) are both refluxed by internal reflux.

6. The energy-saving high-purity hydrogen chloride production process system according to any one of claims 1 to 4, characterized in that: The light component removal tower (6) has a light component extraction outlet at the top.

7. The energy-saving high-purity hydrogen chloride production process system according to any one of claims 1 to 4, characterized in that: The bottom extraction pipeline of the light removal tower (6) is connected to the tube side inlet of the light removal tower reboiler (8), and the tube side outlet of the light removal tower reboiler (8) is connected to the bottom reflux port of the light removal tower (6) through a pipeline.

8. The energy-saving high-purity hydrogen chloride production process system according to any one of claims 1 to 4, characterized in that: The product tower (9) has a light component extraction port at the top, a high-purity hydrogen chloride product extraction port at the side line, and a heavy component extraction port at the bottom.

9. The energy-saving high-purity hydrogen chloride production process system according to any one of claims 1 to 4, characterized in that: The compressor is a screw compressor, a piston compressor or a centrifugal compressor.

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