A kind of hydrogen bromide purification device and method

Abstract

The present invention relates to a hydrogen bromide purification device and method, and belongs to the technical field of fine chemical industry. The crude hydrogen bromide enters a de-weighting tower through a feed pipeline and a de-weighting tower feed port for rectification, heavy impurities are removed at the bottom of the de-weighting tower, and the hydrogen bromide with the heavy impurities removed is discharged from the de-weighting tower discharge port and then enters the de-lighting tower through the feed port of the de-lighting tower for rectification, and light impurities are removed at the top of the de-lighting tower, and the hydrogen bromide with the light impurities removed is discharged from the de-lighting tower discharge port and then enters the product collector through the feed port of the product collector, and at the same time, the liquid hydrogen bromide is tested; the hydrogen bromide collected from the feed port of the product collector is cooled; the hydrogen bromide in the product collector is heated after the test is qualified, and the liquid hydrogen bromide enters the filling bottle along the filling pipeline drawn from the bottom to the top in the product collector through the filling pump. The process is simple, the equipment investment is small, the energy consumption is low, the environmental pollution is small, the economy is good, and it is easy to realize industrial production.

Description

Technical Field

[0001] The invention relates to a hydrogen bromide purification device and method, belonging to the technical field of fine chemical industry. Background Art

[0002] Hydrogen bromide has become an indispensable raw material gas for polysilicon etching of 8-inch and 12-inch chips due to its high selectivity for etching raw materials and its ability to precisely control etching morphology and angle. It is one of the core gases controlling the chip manufacturing process. However, hydrogen bromide is highly corrosive, especially in the presence of water, and can corrode most metal products. Therefore, the purification of hydrogen bromide, especially the removal of water, is the key to process control.

[0003] Chinese patent application 95191144.9 uses crude hydrogen bromide to prepare high-purity hydrogen bromide with a purity of 99.999% through continuous distillation operation, but the problem is that the purification process requires that the water content of the crude product shall not exceed 2ppm, while the water content of crude hydrogen bromide is above 10ppm, and the method has certain limitations. The adsorption method has low equipment requirements and good water treatment effect, but the adsorbent currently uses molecular sieves and silica gel materials, which are easy to adsorb a certain amount of hydrogen bromide, and the heat release during water absorption is large. When the water content is high, the heat release is even greater, and can even reach above 100°C, which brings great safety hazards. In addition, it is difficult to desorb and recycle the adsorbent, and it is basically replaced, and the gas in the pipeline needs to be replaced before and after the replacement, resulting in a large waste of materials and time, affecting the actual production capacity.

[0004] Other processes involving water removal, such as concentrated sulfuric acid method, chemical reaction adsorption method or phosphorus tribromide spray absorption (Chinese patent application 201310220850.8), are affected by adsorption equilibrium or the introduction of new media, and it is difficult to fully realize industrial continuous production. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a hydrogen bromide purification device and method. The hydrogen bromide is purified by continuous distillation to achieve a purity of 99.999% or above, which is simple and practical, can be operated continuously, and is suitable for large-scale industrial production.

[0006] To achieve the above object, the technical solution of the present invention is as follows:

[0007] A hydrogen bromide purification and filling device, comprising a heavy removal tower, a light removal tower, a product collector, a filling pipe, a filling pump and a filling bottle;

[0008] Both the de-weighting tower and the de-lighting tower are distillation towers, and are composed of a tower top, a tower column and a tower bottom. The tower top is provided with a condensing reflux device, and the tower bottom is provided with a heating device and a sewage outlet; the tower column is provided with a temperature control device; a de-weighting tower feed port is provided in the middle of the de-weighting tower column, a feed pipeline is connected to the de-weighting tower feed port, and a de-weighting tower discharge port is provided on the upper part of the de-weighting tower column; a de-lighting tower feed port is provided on the upper part of the de-lighting tower column, and a de-lighting tower discharge port is provided on the lower part of the de-lighting tower column; a light component impurity discharge port is provided on the top of the de-lighting tower column;

[0009] The top of the product collector is provided with a feed port and a discharge port. Two sets of heat exchange devices are arranged in the product collector, one set of heat exchange devices is used to cool the materials entering from the feed port, and the other set of heat exchange devices is used to heat the materials in the product tank;

[0010] The discharge port of the de-heavy tower is connected to the feed port of the de-lightness tower through a pipeline, the discharge port of the de-lightness tower is connected to the feed port of the product collector through a pipeline, the filling pipeline is led out from the bottom to the top along the inside of the product collector and then connected to the inlet of the filling pump, and the outlet of the filling pump is connected to the filling bottle through a pipeline; a detection port is provided on the connecting pipeline between the discharge port of the de-lightness tower and the product collector.

[0011] Preferably, the device further comprises a gas bus, the inlet of the gas bus is connected to the outlet of the filling pump via a pipeline, and the outlet of the gas bus is connected to the filling bottle.

[0012] Preferably, the theoretical plate numbers of the de-weighting tower and the de-lighting tower are independently 30 to 60; the heights of the de-weighting tower and the de-lighting tower are independently 6 m to 14 m, and the diameters are independently 0.1 m to 1 m.

[0013] Preferably, the heavy-removal tower and the light-removal tower are independently packed distillation towers or plate distillation towers.

[0014] Preferably, the de-heavy tower and the de-light tower are packed distillation towers, the packings are independently θ rings, ball rings, Raschig rings or structured packings, and the diameters of the packings used are independently 2 mm to 25 mm.

[0015] Preferably, the filling pump is a diaphragm pump or a planar pump.

[0016] Preferably, the materials of the feed pipeline and the de-weighting tower are independently Hastelloy; the materials of the de-weighting tower, product collector, filling bottle, filling pipeline and connecting pipeline are independently stainless steel, nickel-plated stainless steel or polytetrafluoroethylene-sprayed stainless steel.

[0017] A method for purifying hydrogen bromide, the method comprising the following steps:

[0018] The crude hydrogen bromide enters the de-weighting tower through the feed port of the de-weighting tower through the feed pipeline for rectification, heavy impurities are removed at the bottom of the de-weighting tower, the hydrogen bromide with the heavy impurities removed is discharged from the discharge port of the de-weighting tower and then enters the de-lighting tower through the feed port of the de-lighting tower for rectification, light impurities are removed at the top of the de-lighting tower, the hydrogen bromide with the light impurities removed is discharged from the discharge port of the de-lighting tower and then enters the product collector through the feed port of the product collector, and the liquid hydrogen bromide is tested at the same time; the hydrogen bromide collected from the feed port of the product collector is cooled; the hydrogen bromide in the product collector is heated after being tested and the liquid hydrogen bromide enters the filling bottle along the filling pipeline led from bottom to top in the product collector through the filling pump;

[0019] Among them, the column temperature in the de-heavy tower is -65~30℃, the distillation pressure is 0~3MPa, and the reflux ratio is 1~100; the column temperature in the light-removal tower is -70~25℃, the distillation pressure is 0~3MPa, and the reflux ratio is 1~300; at the same time, the temperature in the column of the de-heavy tower is higher than that in the column of the light-removal tower.

[0020] The temperature of the de-weighting tower and the bottom of the de-weighting tower ensures that the heavy component impurities in the crude hydrogen bromide are in the liquid phase while the hydrogen bromide is in the gas phase. The temperature of the top of the tower ensures that the gaseous hydrogen bromide is cooled to form a liquid phase, and is condensed from the top of the tower under the action of its own gravity and refluxed into the column for distillation.

[0021] Preferably, the temperature of the deheaving tower and the column in the deweighting tower is -40 to 25°C, and the temperature in the deheaving tower column is higher than the temperature in the lightness removing tower column.

[0022] Preferably, the feed flow rate of the crude hydrogen bromide is 5 to 50 L / min.

[0023] Beneficial Effects

[0024] (1) The hydrogen bromide purification process of the present invention is simple, has small equipment investment, low energy consumption, small environmental pollution, good economy, and is easy to realize industrial production.

[0025] (2) The purification process of the present invention can produce high-purity hydrogen bromide with a purity of 99.999% or above.

[0026] (3) The present invention reduces the corrosion resistance requirements of subsequent equipment of the deweighting tower by optimizing the purification process, reduces costs, and reduces the amount of refrigerant used. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the structure of the device of the present invention;

[0028] Among them, 1-heavy removal tower, 2-light removal tower, 3-product collector, 4-filling pipeline, 5-filling pump, 6-filling bottle. DETAILED DESCRIPTION

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

[0030] In the following embodiments:

[0031] A hydrogen bromide purification and filling device comprises a heavy removal tower 1, a light removal tower 2, a product collector 3, a filling pipe 4, a filling pump 5 and a filling bottle 6;

[0032] Both the de-weighting tower 1 and the de-lighting tower 2 are distillation towers, and are composed of a tower top, a tower column and a tower bottom. The tower top is provided with a condensing reflux device, and the tower bottom is provided with a heating device and a sewage outlet; the tower columns are provided with temperature control devices; a de-weighting tower feed port is provided in the middle of the tower column of the de-weighting tower 1, and a feed pipeline is connected to the de-weighting tower feed port, and a de-weighting tower discharge port is provided at the upper part of the tower column of the de-weighting tower 1; a de-lighting tower feed port is provided at the upper part of the tower column of the de-lighting tower 2, and a de-lighting tower discharge port is provided at the lower part of the tower column of the de-lighting tower 2; a light component impurity discharge port is provided at the top of the de-lighting tower 2;

[0033] A feed port and a discharge port are provided at the top of the product collector 3. Two sets of heat exchange devices are provided in the product collector 3. One set of heat exchange devices is used to cool the materials entering the feed port, and the other set of heat exchange devices is used to heat the materials in the product tank.

[0034] The discharge port of the de-heavy tower is connected to the feed port of the de-lightness tower through a pipeline, the discharge port of the de-lightness tower is connected to the feed port of the product collector 3 through a pipeline, the filling pipeline 4 is led out from the bottom to the top along the inside of the product collector 3 and then connected to the inlet of the filling pump 5, and the outlet of the filling pump 5 is connected to the filling bottle 6 through a pipeline; a detection port is provided on the connecting pipeline between the discharge port of the de-lightness tower and the product collector 3.

[0035] The device further comprises a gas bus, the inlet of which is connected to the outlet of the filling pump 5 through a pipeline, and the outlet of the gas bus is connected to the filling bottle 6 .

[0036] Before purification, first use a vacuum pump to pre-treat each component of the purification device, then use high-purity nitrogen to purge and replace the residual air and moisture in the system to complete the pre-treatment of the dehydration device before use; set the temperature in the tower to 10°C; connect the steel cylinder containing the crude hydrogen bromide to the feed pipeline.

[0037] A method for purifying hydrogen bromide, the method comprising the following steps:

[0038] The crude hydrogen bromide enters the de-weighting tower 1 through the de-weighting tower feed port through a feed pipeline for rectification, heavy impurities are removed at the bottom of the de-weighting tower, the hydrogen bromide with the heavy impurities removed is discharged from the de-weighting tower discharge port and then enters the de-lighting tower 2 through the lightness removal tower feed port for rectification, light impurities are removed at the top of the lightness removal tower, the hydrogen bromide with the light impurities removed is discharged from the lightness removal tower discharge port and then enters the product collector 3 through the feed port, and at the same time, the liquid hydrogen bromide is tested; the hydrogen bromide collected from the feed port of the product collector 3 is cooled; the hydrogen bromide in the product collector 3 is heated after being tested and the liquid hydrogen bromide enters the filling bottle 6 along the filling pipeline 4 led from the bottom to the top in the product collector 3 through the filling pump 5.

[0039] The composition of the crude hydrogen bromide gas (98.5%, volume ratio) is shown in Table 1.

[0040] Table 1

[0041] name Detection value (volume value, ppm) Component boiling point (℃, 1atm) hydrogen 6800 -256 nitrogen 3500 -196 Oxygen + Argon 800 -183，-185 Carbon monoxide 400 -192 carbon dioxide 3500 -78 Methane + Acetylene 100 -162，-83 water 70 100 Hydrogen bromide 98.5% (purity) -67

[0042] Example 1

[0043] In this embodiment, both the de-weighting tower 1 and the de-lightening tower 2 are packed towers, the de-weighting tower 1 is 8m high, 0.5mm in diameter, 40 theoretical plates, and has a built-in 5mm diameter θ ring packing. The de-lightening tower 2 is 8m high, 0.5mm in diameter, 30 theoretical plates, and has a built-in 5mm diameter θ ring packing. The feed pipeline and the de-weighting tower 1 are made of Hastelloy, and the de-lightening tower 2, the product collector 3 and the filling bottle 6 are made of stainless steel. The filling pump 5 is a diaphragm pump.

[0044] The flow rate of crude hydrogen bromide was 30 L / min.

[0045] The parameters of the de-weighting tower 1 are set as follows: tower temperature -15°C, pressure 0.9MPa, and reflux ratio 20. In this state, hydrogen bromide vaporizes and rises, and heavy components such as water condense and gather at the bottom of the de-weighting tower in liquid or solid form, thereby achieving the removal of heavy components.

[0046] The parameters of the light removal tower 2 are set as follows: tower temperature -25°C, pressure 0.9MPa, and reflux ratio 50. In this state, hydrogen bromide condenses, collects at the bottom of the light removal tower in liquid form, and is transferred to the product tank in liquid form. Other light components are still in gaseous state and are removed at the top of the light removal tower.

[0047] After the impurity test is qualified, hydrogen bromide is stored in the product tank in liquid form and pressurized to the filling system by a diaphragm pump for filling into the cylinder. After testing, the main components and contents of purified hydrogen bromide are shown in Table 2.

[0048] Example 2

[0049] In this embodiment, the de-weighting tower 1 is 14 mm high, 1 m in diameter, has a theoretical plate number of 60, and has a built-in 25 mm diameter ball ring filler. The de-lightness tower 2 is 14 m high, 1 m in diameter, has a theoretical plate number of 60, and has a built-in 25 mm diameter Raschig ring filler. The feed pipeline and the de-weighting tower 1 are made of Hastelloy, and the de-lightness tower 2, the product collector 3 and the filling bottle 6 are made of stainless steel. The filling pump 5 is a diaphragm pump.

[0050] The flow rate of crude hydrogen bromide was 30 L / min.

[0051] The parameters of deweighting tower 1 are set as: column temperature -64°C, pressure 0MPa, and reflux ratio 80.

[0052] The parameters of the light removal tower 2 are set as: column temperature -70°C, pressure 0MPa, and reflux ratio 200.

[0053] After testing, the main components and contents of purified hydrogen bromide are shown in Table 2.

[0054] Example 3

[0055] In this embodiment, the de-weighting tower 1 is 6 mm high, 0.1 m in diameter, has a theoretical plate number of 40, and has a built-in 3 mm diameter ball ring filler. The de-lightness tower 2 is 6 m high, 0.1 m in diameter, has a theoretical plate number of 30, and has a built-in 3 mm diameter Raschig ring filler. The feed pipeline and the de-weighting tower 1 are made of Hastelloy, and the de-lightness tower 2, the product collector 3 and the filling bottle 6 are made of stainless steel. The filling pump 5 is a diaphragm pump.

[0056] The flow rate of crude hydrogen bromide was 30 L / min.

[0057] The parameters of deweighting tower 1 are set as follows: tower temperature 30°C, pressure 2.3MPa, and reflux ratio 80.

[0058] The parameters of the light removal tower 2 are set as follows: column temperature 20°C, pressure 2.3MPa, and reflux ratio 280.

[0059] After testing, the main components and contents of purified hydrogen bromide are shown in Table 2.

[0060] Table 2

[0061]

[0062] In summary, the invention includes but is not limited to the above embodiments. Any equivalent substitution or partial improvement made under the spirit and principle of the invention shall be deemed to be within the protection scope of the invention.

Claims

1. A method for purifying hydrogen bromide, characterized in that: The method uses a hydrogen bromide purification and filling device for purification, the device comprising a heavy removal tower (1), a light removal tower (2), a product collector (3), a filling pipeline (4), a filling pump (5) and a filling bottle (6); The de-weighting tower (1) and the de-lighting tower (2) are both distillation towers, and both consist of a tower top, a tower column and a tower bottom. The tower top is provided with a condensing reflux device, and the tower bottom is provided with a heating device and a sewage outlet. The tower columns are provided with a temperature control device. The de-weighting tower (1) has a de-weighting tower feed port in the middle of the tower column, and a feed pipeline is connected to the de-weighting tower feed port. The de-weighting tower (1) has a de-weighting tower discharge port at the top of the tower column. The de-lighting tower (2) has a de-lighting tower feed port at the top of the tower column, and a de-lighting tower discharge port at the bottom of the tower column. The de-lighting tower (2) has a de-lighting tower discharge port at the top of the tower column. The top of the product collector (3) is provided with a feed inlet and a discharge inlet. Two sets of heat exchange devices are provided inside the product collector (3), one set of heat exchange devices is used to cool the material entering the feed inlet, and the other set of heat exchange devices is used to heat the material in the product tank; The discharge port of the de-heavy tower is connected to the feed port of the de-light tower through a pipeline, the discharge port of the de-light tower is connected to the feed port of the product collector (3) through a pipeline, the filling pipeline (4) is led from bottom to top along the inside of the product collector (3) and then to the discharge port and connected to the inlet of the filling pump (5), the outlet of the filling pump (5) is connected to the filling bottle (6) through a pipeline; a detection port is provided on the connecting pipeline between the discharge port of the de-light tower and the product collector (3); The feed pipeline and the de-weighting tower (1) are made of Hastelloy alloy respectively; the de-weighting tower (2), the product collector (3), the filling bottle (6), the filling pipeline (4) and the connecting pipeline are made of stainless steel respectively; The method steps are as follows: The crude hydrogen bromide enters a de-heavy tower (1) through a feed pipeline from a de-heavy tower feed port for distillation, heavy impurities are removed at the bottom of the de-heavy tower, the hydrogen bromide from which the heavy impurities are removed is discharged from a de-heavy tower discharge port and then enters a de-light tower (2) through a feed port for distillation, light impurities are removed at the top of the de-light tower, the hydrogen bromide from which the light impurities are removed is discharged from a de-light tower discharge port and then enters a product collector (3) through a feed port of the product collector (3), and at the same time, the liquid hydrogen bromide is tested; the hydrogen bromide collected from the feed port of the product collector (3) is cooled; after passing the test, the hydrogen bromide in the product collector (3) is heated, and the liquid hydrogen bromide is passed through a filling pump (5) and then enters a filling bottle (6); The column temperature of the de-weighting tower (1) is -65~30°C, the distillation pressure is 0~3MPa, and the reflux ratio is 1~100; the column temperature of the de-lighting tower (2) is -70~25°C, the distillation pressure is 0~3MPa, and the reflux ratio is 1~300; and the temperature in the column of the de-weighting tower (1) is higher than the temperature in the column of the de-lighting tower (2).

2. A method for purifying hydrogen bromide as claimed in claim 1, characterized in that: The device also includes a gas bus, the inlet of the gas bus is connected to the outlet of the filling pump (5) through a pipeline, and the outlet of the gas bus is connected to the filling bottle (6).

3. A method for purifying hydrogen bromide as claimed in claim 1, characterized in that: The theoretical plate numbers of the de-weighting tower (1) and the de-lighting tower (2) are independently 30 to 60; the heights of the de-weighting tower (1) and the de-lighting tower (2) are independently 6 to 14 m, and the diameters are independently 0.1 to 1 m.

4. A method for purifying hydrogen bromide as claimed in claim 1, characterized in that: The de-heavy tower (1) and the de-light tower (2) are independently packed distillation towers or plate distillation towers.

5. A method for purifying hydrogen bromide as claimed in claim 1, characterized in that: The de-heavy tower (1) and the de-light tower (2) are packed distillation towers, the packings are independently θ rings, ball rings, Raschig rings or structured packings, and the diameters of the packings used are independently 2 to 25 mm.

6. A method for purifying hydrogen bromide as claimed in claim 1, characterized in that: The filling pump (5) is a diaphragm pump or a planar pump.

7. A method for purifying hydrogen bromide as claimed in claim 1, characterized in that: The column temperature of the de-weighting tower (1) and the de-heavy tower (2) is -40 to 25°C, and the temperature in the column of the de-weighting tower (1) is higher than the temperature in the column of the de-lighting tower (2).

8. A method for purifying hydrogen bromide as claimed in claim 1, characterized in that: The feed flow rate of the crude hydrogen bromide is 5-50 L / min.

9. A method for purifying hydrogen bromide as claimed in claim 1, characterized in that: The filling pipeline (4) and the connecting pipeline are made of stainless steel with a nickel plated surface or stainless steel with a polytetrafluoroethylene sprayed on the surface.

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