Preparation device of electronic-grade hydrochloric acid

Abstract

The utility model relates to the technical field of electronic chemicals, in particular to an electronic grade hydrochloric acid preparation device which comprises a hydrogen chloride synthesis unit, a first absorption unit, a desorption unit and a second absorption unit which are connected with one another, wherein the hydrogen chloride synthesis unit and the desorption unit are connected with the first absorption unit through pipelines, and the desorption unit is connected with the first absorption unit through at least two pipelines; and the desorption unit is connected with the second absorption unit through a pipeline. According to the preparation device of the electronic grade hydrochloric acid provided by the utility model, the hydrogen chloride synthesis unit, the first absorption unit and the desorption unit are matched to absorb generated diluted hydrochloric acid and form concentrated hydrochloric acid to return to the desorption unit again, so that full desorption of hydrochloric acid is realized, the yield is improved on the premise of ensuring the quality of the electronic grade hydrochloric acid, and the production cost is reduced. Meanwhile, subsequent treatment steps are reduced, the cost is reduced, and pollution is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic chemicals, in particular to a device for preparing electronic-grade hydrochloric acid. Background Art

[0002] With the continuous development of the domestic semiconductor industry, the demand for electronic-grade hydrochloric acid is increasing. At present, the preparation method of electronic-grade hydrochloric acid is mostly to analyze hydrochloric acid and then absorb it with high-purity water. The methods of hydrochloric acid analysis mainly include calcium chloride method, differential pressure method and atmospheric pressure analysis method. Among them, calcium chloride method and differential pressure method can achieve full analysis, but calcium chloride method needs to introduce additional azeotropic agent calcium chloride, the process is complicated, and the system stability has high requirements for operation. The differential pressure method has good operational stability, but high energy consumption. The atmospheric pressure analysis method has a simple process, low energy consumption, good stability, but cannot be completely analyzed. Utility Model Content

[0003] The technical problem solved by the utility model is that the normal pressure analysis method cannot achieve full analysis.

[0004] The technical solution adopted by the utility model to solve its technical problems is:

[0005] A device for preparing electronic grade hydrochloric acid comprises a hydrogen chloride synthesis unit, a first absorption unit, a separation unit and a second absorption unit connected to each other; wherein:

[0006] The hydrogen chloride synthesis unit and the separation unit are both connected to the first absorption unit through pipelines, and the separation unit is connected to the first absorption unit through at least two pipelines;

[0007] The desorption unit is connected to the second absorption unit through a pipeline.

[0008] Preferably, the first absorption unit comprises a crude HCl absorption tower, a first circulation pump and a first cooler which are sequentially connected via pipelines; and a material outlet of the first cooler is connected to the separation unit via a pipeline.

[0009] Preferably, the first absorption unit further comprises an oxidant preparation tank connected to the crude HCl absorption tower.

[0010] Preferably, the separation unit comprises a separation tower, a separation reboiler, a first preheater and a second cooler; the separation tower, the separation reboiler, the first preheater, the second cooler and the crude HCl absorption tower are sequentially connected by pipelines.

[0011] Preferably, the separation unit further comprises a condensation module; the separation tower, the condensation module and the second absorption unit are connected via a pipeline.

[0012] Preferably, the desorption unit further includes a first demister and a second preheater which are arranged between the condensation module and the second absorption unit.

[0013] Preferably, the separation unit further comprises a drying module arranged between the second preheater and the second absorption unit.

[0014] Preferably, the drying module comprises a drying tower and a second demister connected by a pipeline.

[0015] Preferably, the second absorption unit comprises an absorption tower, and a second circulation pump and a third cooler which are sequentially arranged downstream of the absorption tower.

[0016] The beneficial effects of the utility model are:

[0017] The preparation device of electronic-grade hydrochloric acid provided by the utility model can absorb the generated dilute hydrochloric acid by cooperating the hydrogen chloride synthesis unit, the first absorption unit and the separation unit to form concentrated hydrochloric acid which is returned to the separation unit again, thereby achieving full separation of hydrochloric acid. Under the premise of ensuring the quality of electronic-grade hydrochloric acid, the yield is improved, and the subsequent processing steps are reduced, the cost is reduced, and the pollution is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0019] Figure 1 It is a simplified structural diagram of the electronic grade hydrochloric acid preparation device in the utility model.

[0020] In the figure: 1-hydrogen chloride synthesis unit; 2-first absorption unit; 21-crude HCl absorption tower; 22-first circulation pump; 23-first cooler; 24-oxidant preparation tank; 25-oxidant pump; 3-desorption unit; 31-desorption tower; 32-desorption reboiler; 33-first preheater; 34-second cooler; 35-condensation module; 351-first condenser; 352-second condenser; 36-first demister; 37-second preheater; 38-drying module; 381-drying tower; 382-second demister; 383-fourth cooler; 384-sulfuric acid circulation pump; 4-second absorption unit; 41-absorption tower; 42-second circulation pump; 43-third cooler. DETAILED DESCRIPTION

[0021] The present utility model is now further described in detail. The embodiments described below are exemplary and intended to be used to explain the present utility model, but cannot be understood as limiting the present utility model. Based on the embodiments of the present utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present utility model.

[0022] In the description of the present utility model, it should be understood that the terms "first" and "second" are only used to simplify the description, and cannot 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.

[0023] In the present utility model, unless otherwise clearly stipulated and limited, a first feature being "above" or "below" the first feature may include that the first feature is in direct contact with the second feature, or may include that the first feature and the second feature are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" the second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0024] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0025] The existing hydrochloric acid atmospheric pressure analysis method cannot achieve full analysis, and the hydrochloric acid needs to be treated later. In order to solve the problem that the atmospheric pressure analysis method cannot achieve full analysis, the utility model provides a preparation device for electronic grade hydrochloric acid, see Figure 1 As shown, the device includes a connected hydrogen chloride synthesis unit 1, a first absorption unit 2, a separation unit 3 and a second absorption unit 4; the hydrogen chloride synthesis unit 1 and the separation unit 3 are connected to the first absorption unit 2 through pipelines, and the separation unit 3 is connected to the first absorption unit 2 through at least two pipelines; at the same time, the separation unit 3 is connected to the second absorption unit 4 through a pipeline.

[0026] Among them, the hydrogen chloride synthesis unit 1 is used to synthesize crude hydrogen chloride gas; the utility model preferably includes a hydrogen chloride synthesis furnace, and the hydrogen chloride synthesis furnace uses hydrogen and chlorine as raw materials to react and generate crude hydrogen chloride gas; the specific selection of the hydrogen chloride synthesis furnace and the reaction conditions, etc., can be selected according to the needs of the corresponding existing technology.

[0027] During the production process, the crude hydrogen chloride generated by the hydrogen chloride synthesis unit 1 is transported to the first absorption unit 2 through a pipeline, and mass and energy are exchanged with dilute hydrochloric acid in the first absorption unit 2 to produce concentrated hydrochloric acid; wherein the mass concentration of the dilute hydrochloric acid can be determined according to the demand for product quality; preferably, the mass fraction of the concentrated hydrochloric acid produced in this step is about 31%wt; the concentrated hydrochloric acid produced in the first absorption unit 2 is further transported to the separation unit 3 through a pipeline, and separation reaction is carried out in the separation unit 3 to generate hydrogen chloride gas and dilute hydrochloric acid; the hydrogen chloride gas is further transported to the second absorption unit 4 through a pipeline, and the hydrogen chloride gas is absorbed by high-purity water in the second absorption unit 4 to obtain electronic grade hydrochloric acid; in order to achieve full analysis, the utility model preferably transports the dilute hydrochloric acid produced by the separation unit 3 to the first absorption unit 2 through a pipeline, and the dilute hydrochloric acid produced by the separation unit 3 is used to exchange mass and energy with the crude hydrogen chloride gas to generate concentrated hydrochloric acid again, thereby achieving full analysis. Specifically, in the utility model, the separation unit 3 is connected to the first absorption unit 2 through two pipelines, one pipeline is used to transport the concentrated hydrochloric acid produced by the first absorption unit 2 to the separation unit 3, and the other pipeline is used to transport the dilute hydrochloric acid produced by the separation unit 3 to the first absorption unit 2, thereby achieving full separation and avoiding subsequent reprocessing of the unresolved hydrochloric acid.

[0028] The preparation device of electronic grade hydrochloric acid provided by the utility model can absorb the generated dilute hydrochloric acid by cooperating the hydrogen chloride synthesis unit 1, the first absorption unit 2 and the separation unit 3, and form concentrated hydrochloric acid which is returned to the separation unit 3 again, thereby achieving full separation of hydrochloric acid, improving the yield while ensuring the quality of electronic grade hydrochloric acid, and reducing subsequent processing steps, costs and pollution.

[0029] Specifically, the first absorption unit 2 of the present invention preferably includes a crude HCl absorption tower 21, a first circulation pump 22 and a first cooler 23 which are sequentially connected through pipelines; the material outlet of the first cooler 23 is connected to the separation unit 3 through a pipeline.

[0030] The utility model preferably transports the crude hydrogen chloride gas produced by the hydrogen chloride synthesis furnace from the bottom of the hydrogen chloride synthesis furnace to the middle and lower part of the crude HCl absorption tower 21 through a pipeline, and preferably transports the dilute hydrochloric acid to the upper part of the crude HCl absorption tower 21 through a pipeline, so that the crude hydrogen chloride gas and the dilute hydrochloric acid are fully contacted in the crude HCl absorption tower 21, and after mass and energy exchange, concentrated hydrochloric acid is generated, and the concentrated hydrochloric acid is transported to the separation unit 3 through the first circulation pump 22 and the first cooler 23.

[0031] In order to further improve the product quality, the utility model preferably includes the first absorption unit 2 further comprising an oxidant preparation tank 24 connected to the crude HCl absorption tower 21. When the crude HCl absorption tower 21 circulates, an oxidant, such as hydrogen peroxide, potassium permanganate, etc., is prepared through the oxidant preparation tank 24, and the oxidant pump 25 is used to add the oxidant to the absorption circulating liquid to remove trace amounts of arsenic and other materials in the hydrochloric acid, thereby ensuring the quality of the finished electronic grade hydrochloric acid.

[0032] The utility model can remove substances such as arsenic which are difficult to remove in the HCl atmospheric pressure analysis operation by adding an oxidant in the crude HCl absorption process, and can effectively ensure the quality of finished electronic grade hydrochloric acid.

[0033] The preferred separation unit 3 of the utility model includes a separation tower 31, a separation reboiler 32 and a first cooler 33; wherein the separation tower 31, the separation reboiler 32, the first preheater 33 and the second cooler 34; the separation tower 31, the separation reboiler 32, the first preheater 33, the second cooler 34 and the crude HCl absorption tower 21 are connected in sequence by pipelines.

[0034] Specifically, after the concentrated hydrochloric acid undergoes a stripping reaction in the stripping tower 31, the generated hydrogen chloride gas is transported from the top of the stripping tower 31 to the second absorption unit 4 through the corresponding pipeline; the generated dilute hydrochloric acid at the bottom of the stripping tower 31, part of which passes through the stripping reboiler 32 to generate rising steam to maintain the operation of the stripping tower 31, and the other part passes through the first preheater 33 and the second cooler 34 and enters the crude HCl absorption tower 21 to absorb the crude hydrogen chloride gas generated by the HCl synthesis furnace to generate concentrated hydrochloric acid again.

[0035] During operation, the concentrated hydrochloric acid produced in the first absorption unit 2 passes through the first circulation pump 22 and the first cooler 23, and then enters the first preheater 33, exchanges heat with the dilute hydrochloric acid produced in the desorption tower 31, and then enters the desorption tower 31 for desorption.

[0036] In the preferred production process of the utility model, the high-pressure steam produced as a by-product of the hydrogen chloride synthesis furnace is used as a heat source for the desorption reboiler 32, which effectively improves the energy utilization efficiency of the system and reduces the operating cost.

[0037] Since the hydrogen chloride gas generated in the desorption tower 31 is a high-concentration water-containing hydrogen chloride gas, in order to ensure the quality of electronic-grade hydrochloric acid, the desorption unit 3 of the utility model preferably also includes a condensation module 35; the desorption tower 31, the condensation module 35 and the second absorption unit 4 are connected by a pipeline, so that the hydrogen chloride gas generated in the desorption tower 31 is condensed by the condensation module 35, and then enters the second absorption unit 4 after removing the water entrained in the gas; wherein after the condensation module 35 performs condensation, the condensate is saturated hydrochloric acid at the corresponding tower top temperature and pressure, and the saturated hydrochloric acid returns to the top of the desorption tower to maintain the desorption operation, and the condensed hydrogen chloride gas enters the second absorption unit 4.

[0038] The specific structure of the condensation module 35 may be determined according to actual production requirements; the preferred condensation module 35 of the present invention includes a primary condenser 351 and a secondary condenser 352 connected in sequence.

[0039] Furthermore, the preferred desorption unit 3 of the utility model also includes a first demister 36 and a second preheater 37 arranged between the condensation module 35 and the second absorption unit 4. The condensed hydrogen chloride gas passes through the first demister 36 to remove residual trace moisture and then enters the second absorption unit 4 through the second preheater 37.

[0040] The preferred desorption unit 3 of the present invention further includes a drying module 38 disposed between the second preheater 37 and the second absorption unit 4 , so that the hydrogen chloride gas enters the second absorption unit 4 after being dried.

[0041] The drying module 38 in the utility model includes a drying tower 381 and a second demister 382 connected by pipelines, so that the hydrogen chloride gas is dehumidified by sulfuric acid, SiCl4 and other desiccants in the drying tower 381 to remove trace moisture, and then passes through the second demister 382 to remove the entrained trace desiccant, and then enters the second absorption unit 4.

[0042] Furthermore, when the desiccant is sulfuric acid, the drying module 38 also includes a fourth cooler 383 and a sulfuric acid circulation pump 384. The bottom of the drying tower 381, the sulfuric acid circulation pump 384, the fourth cooler 383 and the upper part of the drying tower 381 are connected in sequence through pipelines to realize the circulation of sulfuric acid and improve the drying effect.

[0043] The second absorption unit 4 in the utility model comprises an absorption tower 41, and a second circulation pump 42 and a third cooler 43 which are sequentially arranged downstream of the absorption tower 41; the hydrogen chloride gas is absorbed by high-purity water in the absorption tower 41 to obtain electronic-grade hydrochloric acid, which is then transported to a designated process or container via the second circulation pump 42 and the third cooler 43.

[0044] Another object of the utility model is to provide a method for preparing electronic-grade hydrochloric acid, which is prepared by the electronic-grade hydrochloric acid preparation device as described above; the preparation method comprises the following steps:

[0045] S1: preparing crude hydrogen chloride gas by hydrogen chloride synthesis unit 1;

[0046] S2: transporting the crude hydrogen chloride gas to the first absorption unit 2, and producing concentrated hydrochloric acid by mass and energy exchange with dilute hydrochloric acid; the dilute hydrochloric acid in this step is preferably the dilute hydrochloric acid produced in the separation unit 3;

[0047] S3: Concentrated hydrochloric acid is transported to the separation unit 3 for separation reaction to produce hydrogen chloride gas and dilute hydrochloric acid, the dilute hydrochloric acid is transported to the first absorption unit 2, and the hydrogen chloride gas is transported to the second absorption unit 4 to obtain electronic grade hydrochloric acid.

[0048] The specific operation process and reaction principle of each device and each step are the same as above and will not be repeated in this article.

[0049] The preparation method of electronic grade hydrochloric acid provided by the utility model comprises the following steps: hydrogen and chlorine are passed through a hydrogen chloride synthesis unit 1 to generate hydrogen chloride gas, the hydrogen chloride gas enters a first absorption unit 2 and exchanges mass and energy with dilute hydrochloric acid from a desorption unit 3 to generate ~31%wt concentrated hydrochloric acid, the concentrated hydrochloric acid is passed through a circulation pump and then through a first preheater 23 and heat-exchanged with dilute hydrochloric acid from the desorption unit 3 to enter the desorption unit 3, a desorption reaction occurs in the desorption unit 3 to produce hydrogen chloride gas and dilute hydrochloric acid, and then the hydrogen chloride is absorbed by a second absorption unit 4 to obtain electronic grade hydrochloric acid; the preparation method aims at the insufficiency of normal pressure analysis, and in combination with a hydrogen chloride synthesis system, the dilute hydrochloric acid can be absorbed to form concentrated hydrochloric acid and return to the desorption part again, thereby realizing the full analysis of hydrochloric acid. The high-pressure steam produced as a by-product of the hydrogen chloride synthesis unit can be used as a heat source for the desorption part, which can effectively improve the energy utilization rate of the system.

[0050] Based on the above ideal embodiments of the utility model, the relevant staff can make various changes and modifications without deviating from the technical concept of the utility model through the above description. The technical scope of the utility model is not limited to the content of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A device for preparing electronic grade hydrochloric acid, characterized in that: The invention comprises a hydrogen chloride synthesis unit (1), a first absorption unit (2), a separation unit (3) and a second absorption unit (4) connected to each other; wherein: The hydrogen chloride synthesis unit (1) and the separation unit (3) are both connected to the first absorption unit (2) via pipelines, and the separation unit (3) is connected to the first absorption unit (2) via at least two pipelines; The desorption unit (3) is connected to the second absorption unit (4) via a pipeline.

2. The device for preparing electronic grade hydrochloric acid according to claim 1, characterized in that: The first absorption unit (2) comprises a crude HCl absorption tower (21), a first circulation pump (22) and a first cooler (23) which are connected in sequence via pipelines; a material outlet of the first cooler (23) is connected to the separation unit (3) via a pipeline.

3. The device for preparing electronic grade hydrochloric acid according to claim 2, characterized in that: The first absorption unit (2) further comprises an oxidant preparation tank (24) connected to the crude HCl absorption tower (21).

4. The device for preparing electronic grade hydrochloric acid according to claim 3, characterized in that: The separation unit (3) comprises a separation tower (31), a separation reboiler (32), a first preheater (33) and a second cooler (34); the separation tower (31), the separation reboiler (32), the first preheater (33), the second cooler (34) and the crude HCl absorption tower (21) are sequentially connected via pipelines.

5. The device for preparing electronic grade hydrochloric acid according to claim 4, characterized in that: The separation unit (3) further comprises a condensation module (35); the separation tower (31), the condensation module (35) and the second absorption unit (4) are connected via a pipeline.

6. The device for preparing electronic grade hydrochloric acid according to claim 5, characterized in that: The desorption unit (3) further comprises a first demister (36) and a second preheater (37) which are arranged between the condensation module (35) and the second absorption unit (4).

7. The device for preparing electronic grade hydrochloric acid according to claim 6, characterized in that: The desorption unit (3) further comprises a drying module (38) arranged between the second preheater (37) and the second absorption unit (4).

8. The device for preparing electronic grade hydrochloric acid according to claim 7, characterized in that: The drying module (38) includes a drying tower (381) and a second demister (382) connected via a pipeline.

9. The device for preparing electronic grade hydrochloric acid according to any one of claims 1 to 8, characterized in that: The second absorption unit (4) comprises an absorption tower (41), and a second circulation pump (42) and a third cooler (43) which are sequentially arranged downstream of the absorption tower (41).

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