Novel device for preparing electronic-grade hydrogen chloride by recovering tail gas

Abstract

The utility model relates to a novel device for preparing electronic-grade hydrogen chloride by tail gas recovery, which comprises a water scrubber, a first-stage heavy component removal tower, a second-stage heavy component removal tower and a third-stage light component removal tower which are connected in sequence, hydrogen chloride tail gas is filled into the water scrubber and is subjected to countercurrent absorption with low-temperature diluted hydrochloric acid in the water scrubber, and a high-concentration hydrochloric acid solution is produced; a high-concentration hydrochloric acid solution is conveyed into the first-stage heavy component removal tower through a pipeline and is heated and evaporated through a tower kettle reboiler, hydrogen chloride gas is cooled and refluxed through a condenser at the tower top, hydrogen chloride is concentrated and discharged into the second-stage heavy component removal tower, heavy component removal is conducted on hydrogen chloride through the second-stage heavy component removal tower, and the hydrogen chloride is internally rectified in the third-stage heavy component removal tower after heavy component removal; discharging oxygen, nitrogen, argon, hydrogen, carbon monoxide, trace carbon dioxide and other gases to obtain electronic-grade hydrogen chloride, and collecting the electronic-grade hydrogen chloride through a finished product tank. Therefore, after the hydrogen chloride tail gas is recovered, low-temperature diluted hydrochloric acid absorption, concentration, heavy component removal and rectification are carried out, and purification of the hydrogen chloride tail gas can be completed by using a relatively simple process.

Description

Technical Field

[0001] The present application relates to the technical field of tail gas treatment, and in particular to a new device for recovering tail gas and preparing electronic grade hydrogen chloride. Background Art

[0002] Electronic grade hydrogen chloride is one of the important raw materials for my country's semiconductor and optoelectronic industries, and is a type of electronic special gas. Electronic grade products are mainly used in large-scale integrated circuits, liquid crystal screens, optoelectronic semiconductors, optical fibers, solar polycrystalline silicon cells, solar thin film cells and other fields. Electronic grade hydrogen chloride is mainly used for dry etching, optical fibers, thermal oxidation and crystal growth in the electronics industry. Dry etching, also known as dry etching, refers to a gas-solid reaction. The gas phase products are mainly GaCl2, AsCl2 and hydrogen. When using hydrogen chloride for plasma etching, 5% high-purity hydrogen chloride plus 95% helium are usually used.

[0003] The preparation methods of electronic-grade hydrogen chloride are mainly adsorption and distillation. Showa Denko's electronic-grade hydrogen chloride adopts photolysis adsorption distillation, which first uses a special light source to decompose nitrogen and hydrogen chloride, then removes part of the water in the hydrogen chloride by adsorption, and then removes the remaining impurities by distillation. The existing technology usually adopts the distillation process of electronic-grade hydrogen chloride, which passes through multiple de-heavy and de-light distillation towers. The number of equipment used in the overall process is large, resulting in high energy consumption in the process; or the adsorption distillation process is adopted. This process uses silicon tetrafluoride as an adsorbent to absorb moisture, and then the hydrogen chloride is de-lightened and de-heaved. When silicon tetrafluoride is used as an adsorbent, it has a short service life and a large amount of consumption, which easily pollutes the environment. Utility Model Content

[0004] In view of this, the present application proposes a new device for recovering tail gas to prepare electronic grade hydrogen chloride, which can purify hydrogen chloride using a relatively simple process.

[0005] According to one aspect of the present application, a new device for preparing electronic-grade hydrogen chloride by tail gas recovery is provided, comprising: a water scrubber, a primary de-heavy tower, a secondary de-heavy tower and a tertiary de-light tower;

[0006] The water washing tower, the first-stage de-weighting tower, the second-stage de-weighting tower and the third-stage de-lighting tower are connected in sequence;

[0007] The water washing tower is suitable for connecting to the hydrogen chloride tail gas discharge device to produce concentrated hydrochloric acid solution and discharge it to the primary deweighting tower;

[0008] The first de-weighting tower concentrates the concentrated hydrochloric acid solution into hydrogen chloride gas, and discharges the hydrogen chloride gas to the second de-weighting tower;

[0009] The secondary de-heavy tower removes the heavy hydrogen chloride gas and discharges it to the tertiary de-light tower;

[0010] The three-stage light removal tower distills the hydrogen chloride gas to obtain electronic grade hydrogen chloride.

[0011] In a possible implementation, the water washing tower includes: a primary water washing tower and a secondary water washing tower;

[0012] The primary water scrubber is suitable for connecting to a hydrogen chloride tail gas discharge device, the top is connected to the inside of the secondary water scrubber, the inside is connected to the bottom of the secondary water scrubber, and the bottom is connected to the primary deweighting tower.

[0013] In a possible implementation method, it also includes: a hydrochloric acid high-level tank;

[0014] The hydrochloric acid high-level tank is connected and arranged between the primary water washing tower and the primary deweighting tower.

[0015] In a possible implementation, the method further includes: a first-stage deweighting condenser and a first-stage reboiler;

[0016] The inlet end of the first-stage de-weighting condenser is connected to the top of the first-stage de-weighting tower, the first outlet end is connected to the inside of the second-stage de-weighting tower, and the second outlet end is connected to the inside of the first-stage de-weighting tower;

[0017] The primary reboiler is connected to the bottom loop of the primary deweighting tower.

[0018] In a possible implementation, the method further includes: a secondary deweighting condenser and a secondary reboiler;

[0019] The inlet end of the secondary de-weighting condenser is connected to the top of the secondary de-weighting tower, the second outlet end is connected to the inside of the tertiary de-weighting tower, and the second outlet end is connected to the inside of the secondary de-weighting tower;

[0020] The secondary reboiler is connected to the bottom loop of the secondary deweighting tower.

[0021] In a possible implementation, a low-hydrochloric acid discharge pipeline is connected to the bottom of the primary deweighting tower.

[0022] In a possible implementation manner, the bottom of the secondary deweighting tower is connected to a heavy component discharge pipeline.

[0023] In a possible implementation, the method further includes: a first-stage light removal condenser and a third-stage reboiler;

[0024] The inlet end of the primary light removal condenser is connected to the top of the tertiary light removal tower, the first outlet end is connected to the inside of the tertiary light removal tower, and the second outlet end is suitable for connecting to a tail gas absorption device;

[0025] The three-stage reboiler is connected to the bottom loop of the three-stage light removal tower.

[0026] In one possible implementation, it also includes: a product storage tank;

[0027] The product storage tank is connected to the bottom of the three-stage light removal tower.

[0028] The beneficial effect of the new device for preparing electronic-grade hydrogen chloride by tail gas recovery of the embodiment of the present application: hydrogen chloride tail gas is filled into the inside of the water scrubber, and is countercurrently absorbed with the low-temperature dilute hydrochloric acid inside the water scrubber, and a high-concentration hydrochloric acid solution is output, and the high-concentration hydrochloric acid solution is transported to the inside of the primary de-weighting tower by pipeline, and is heated and evaporated by the tower kettle reboiler, and the condenser price hydrogen chloride gas at the top of the tower is cooled and refluxed, and the hydrogen chloride is concentrated and discharged into the inside of the secondary de-weighting tower, and the secondary de-weighting tower de-weights hydrogen chloride, and the internal rectification of the three-stage de-lightening tower of hydrogen chloride after de-weighting discharges oxygen, nitrogen, argon, hydrogen, carbon monoxide, trace carbon dioxide and other gases, and electronic-grade hydrogen chloride is obtained, and collected by the finished product tank. In this way, after the hydrogen chloride tail gas is recovered, low-temperature dilute hydrochloric acid is absorbed, concentrated, de-weighted and rectified, and the purification of hydrogen chloride tail gas can be completed using a relatively simple process, and no environmental pollution will be caused during the purification process.

[0029] Other features and aspects of the present application will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the present application and, together with the description, serve to explain the principles of the present application.

[0031] Figure 1 A schematic diagram showing a new device for recovering tail gas to prepare electronic grade hydrogen chloride according to an embodiment of the present application. DETAILED DESCRIPTION

[0032] Various exemplary embodiments, features and aspects of the present application will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise specified.

[0033] Among them, it needs to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the utility model or simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model.

[0034] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0035] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0036] In addition, in order to better illustrate the present application, numerous specific details are given in the following specific embodiments. It should be understood by those skilled in the art that the present application can also be implemented without certain specific details. In some examples, methods, means, components and circuits well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present application.

[0037] See also Figure 1 The new device for preparing electronic-grade hydrogen chloride by recycling tail gas in the embodiment of the present application comprises: a water washing tower, a primary de-weighting tower 310, a secondary de-weighting tower 320 and a tertiary de-lighting tower 400 connected in sequence, the water washing tower is suitable for connecting to a hydrogen chloride tail gas discharge device, and is used to produce a concentrated hydrochloric acid solution and discharge it to the primary de-weighting tower 310, the primary de-weighting tower 310 concentrates the concentrated hydrochloric acid solution into hydrogen chloride gas, and discharges it to the secondary de-weighting tower 320, the secondary de-weighting tower 320 de-heavy hydrogen chloride gas, and discharges it to the tertiary de-lighting tower 400, the tertiary de-lighting tower 400 distills the hydrogen chloride gas to obtain electronic-grade hydrogen chloride.

[0038] In this embodiment, the hydrogen chloride tail gas is filled into the inside of the water scrubber, and is countercurrently absorbed with the low-temperature dilute hydrochloric acid inside the water scrubber to produce a high-concentration hydrochloric acid solution, which is transported to the inside of the primary de-weighting tower 310 through a pipeline, heated and evaporated by the tower kettle reboiler, and the condenser price hydrogen chloride gas at the top of the tower is cooled and refluxed, and the hydrogen chloride is concentrated and discharged into the inside of the secondary de-weighting tower 320, and the secondary de-weighting tower 320 de-weights the hydrogen chloride, and the internal distillation of the hydrogen chloride tertiary de-lightening tower 400 after de-weighting discharges oxygen, nitrogen, argon, hydrogen, carbon monoxide, trace carbon dioxide and other gases to obtain electronic grade hydrogen chloride, and collect it through the finished product tank. In this way, after the hydrogen chloride tail gas is recovered, low-temperature dilute hydrochloric acid is absorbed, concentrated, de-weighted and distilled, and the purification of the hydrogen chloride tail gas can be completed using a relatively simple process, and no environmental pollution will be caused during the purification process.

[0039] In a specific embodiment, the water scrubber includes: a primary water scrubber 110 and a secondary water scrubber 120. The primary water scrubber 110 is connected to a hydrogen chloride tail gas discharge device to receive hydrogen chloride tail gas. The top of the primary water scrubber 110 is connected to the interior of the secondary water scrubber 120. Incompletely absorbed hydrogen chloride tail gas or other impurity gases will enter the secondary water scrubber 120 through the top channel of the primary water scrubber 110. The gas entering the secondary water scrubber 120 is reversely exchanged and absorbed with continuously replenished pure water. Impurity gases that cannot be absorbed are discharged to the tail gas device for treatment. The low-concentration hydrochloric acid produced in the kettle of the secondary water scrubber 120 overflows to the kettle of the primary water scrubber 110 through the potential difference for recycling.

[0040] In a specific embodiment, it also includes: a hydrochloric acid high-level tank 200, which is connected between the primary water washing tower 110 and the primary deweighting tower 310, so that the hydrochloric acid concentration inside the water washing tower reaches 31% and is continuously transmitted to the hydrochloric acid high-level tank 200, and then discharged into the first deweighting tower 310.

[0041] In a specific embodiment, it also includes: a primary de-weighting condenser 311 and a primary reboiler 312, the primary reboiler 312 is connected to the bottom loop of the primary de-weighting tower 310, and the hydrochloric acid in the primary de-weighting tower 310 is heated and evaporated through the reboiler. The bottom of the primary de-weighting tower 310 is connected to a low-concentration hydrochloric acid discharge pipeline, and the remaining low-concentration hydrochloric acid is discharged through the pipeline.

[0042] In this embodiment, the inlet end of the primary de-weighting condenser 311 is connected to the top of the primary de-weighting tower 310, the first outlet end is connected to the interior of the secondary de-weighting tower 320, and the second outlet end is connected to the interior of the primary de-weighting tower 310. The hydrogen chloride gas of the primary condenser of the primary de-weighting tower 310 is cooled and refluxed, and the hydrogen chloride in the primary de-weighting tower 310 is concentrated to more than 90% and discharged to the secondary de-weighting tower 320 through the gas phase at the top condenser.

[0043] In a specific embodiment, it also includes: a secondary de-weighting condenser 321 and a secondary reboiler 322, the inlet end of the secondary de-weighting condenser 321 is connected to the top of the secondary de-weighting tower 320, the second outlet end is connected to the inside of the tertiary de-weighting tower 400, the second outlet end is connected to the inside of the secondary de-weighting tower 320, and the secondary reboiler 322 is connected to the bottom loop of the secondary de-weighting tower 320. During the distillation separation process, heavy components such as moisture and metal ions are discharged from the bottom kettle of the de-weighting tower through a pipeline, and the de-weighted hydrogen chloride flows out from the top gas phase of the secondary de-weighting tower 320 and enters the tertiary de-lighting tower 400 for distillation.

[0044] The bottom of the secondary deweighting tower 320 is connected to a heavy component discharge pipeline for discharging heavy components such as water and metal ions.

[0045] In a specific embodiment, it also includes: a primary light removal condenser 410 and a tertiary reboiler 420, the inlet end of the primary light removal condenser 410 is connected to the top of the tertiary light removal tower 400, the first outlet end is connected to the inside of the tertiary light removal tower 400, and the second outlet end is suitable for connecting to the tail gas absorption device. The first light removal condenser of the tertiary light removal tower 400 discharges oxygen, nitrogen, argon, hydrogen, carbon monoxide, trace carbon dioxide, and hydrocarbon gas into the tail gas system through a pipeline, and the tertiary reboiler 420 is connected to the bottom loop of the tertiary light removal tower 400. It also includes: a product storage tank 500, which is connected to the bottom of the tertiary light removal tower 400, and the bottom tertiary reboiler 420 of the tertiary light removal tower 400 discharges the rectified electronic grade hydrogen chloride into the interior of the finished product storage tank for storage.

[0046] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A new device for recovering tail gas to prepare electronic grade hydrogen chloride, characterized in that: include: Water washing tower, primary de-heavy tower, secondary de-heavy tower and tertiary de-light tower; The water washing tower, the first-stage de-weighting tower, the second-stage de-weighting tower and the third-stage de-lighting tower are connected in sequence; The water washing tower is suitable for connecting to the hydrogen chloride tail gas discharge device to produce concentrated hydrochloric acid solution and discharge it to the primary deweighting tower; The first de-weighting tower concentrates the concentrated hydrochloric acid solution into hydrogen chloride gas, and discharges the hydrogen chloride gas to the second de-weighting tower; The secondary de-heavy tower removes the heavy hydrogen chloride gas and discharges it to the tertiary de-light tower; The three-stage light removal tower distills the hydrogen chloride gas to obtain electronic grade hydrogen chloride.

2. The novel device for preparing electronic grade hydrogen chloride by recycling tail gas according to claim 1 is characterized in that: The water washing tower comprises: a primary water washing tower and a secondary water washing tower; The primary water scrubber is suitable for connecting to a hydrogen chloride tail gas discharge device, the top is connected to the inside of the secondary water scrubber, the inside is connected to the bottom of the secondary water scrubber, and the bottom is connected to the primary deweighting tower.

3. The novel device for preparing electronic grade hydrogen chloride by tail gas recovery according to claim 2 is characterized in that: Also includes: Hydrochloric acid high-level tank; The hydrochloric acid high-level tank is connected and arranged between the primary water washing tower and the primary deweighting tower.

4. The new device for preparing electronic grade hydrogen chloride by recycling tail gas according to any one of claims 1 to 3, characterized in that: Also includes: A first-stage deweighting condenser and a first-stage reboiler; The inlet end of the first-stage de-weighting condenser is connected to the top of the first-stage de-weighting tower, the first outlet end is connected to the inside of the second-stage de-weighting tower, and the second outlet end is connected to the inside of the first-stage de-weighting tower; The primary reboiler is connected to the bottom loop of the primary deweighting tower.

5. The new device for preparing electronic grade hydrogen chloride by recycling tail gas according to any one of claims 1 to 3, characterized in that: Also includes: Two-stage de-weighting condenser and two-stage reboiler; The inlet end of the secondary de-weighting condenser is connected to the top of the secondary de-weighting tower, the second outlet end is connected to the inside of the tertiary de-weighting tower, and the second outlet end is connected to the inside of the secondary de-weighting tower; The secondary reboiler is connected to the bottom loop of the secondary deweighting tower.

6. The novel device for preparing electronic grade hydrogen chloride by recycling tail gas according to claim 4 is characterized in that: The bottom of the primary deweighting tower is connected with a low-hydrochloric acid discharge pipeline.

7. The novel device for preparing electronic grade hydrogen chloride by recycling tail gas according to claim 5 is characterized in that: The bottom of the secondary deweighting tower is connected to a heavy component discharge pipeline.

8. The new device for preparing electronic grade hydrogen chloride by recycling tail gas according to any one of claims 1 to 3, characterized in that: Also includes: One-stage light removal condenser and three-stage reboiler; The inlet end of the primary light removal condenser is connected to the top of the tertiary light removal tower, the first outlet end is connected to the inside of the tertiary light removal tower, and the second outlet end is suitable for connecting to a tail gas absorption device; The three-stage reboiler is connected to the bottom loop of the three-stage light removal tower.

9. The novel device for preparing electronic grade hydrogen chloride by recycling tail gas according to claim 8, characterized in that: Also includes: Product storage tanks; The product storage tank is connected to the bottom of the three-stage light removal tower.

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