KR101203490B1 - A production method and production system for high purity hydrogen chloride - Google Patents

Abstract

PURPOSE: A manufacturing method of high purity hydrogen chloride and a manufacturing system of the same are provided to directly react hydrogen chlorine to synthesize hydrogen chloride in a completely sealed drying technique and to remove excessive hydrogen from the hydrogen chloride in a distillation column. CONSTITUTION: A manufacturing method of high purity hydrogen chloride includes the following steps: refined hydrogen is generated by removing moisture and oxygen from crude hydrogen; refined chlorine is generated by removing moisture and oxygen from crude chlorine; the refined hydrogen and the refined chlorine are reacted to synthesize hydrogen chloride; and the synthesized hydrogen chloride is compressively cooled. [Reference numerals] (AA) Item; (BB) Raw materials; (CC) Raw material refinement; (DD) Synthesis; (EE) Refinement; (FF) Storage tank; (GG) Purity; (HH) Impurities

Description

High Purity Hydrogen Chloride Manufacturing Method and Production System {A PRODUCTION METHOD AND PRODUCTION SYSTEM FOR HIGH PURITY HYDROGEN CHLORIDE}

The present invention relates to a high-purity hydrogen chloride production method and production system, and more specifically, iii) purifying crude hydrogen and crude chlorine, each raw material with a purity of 99.999% or more; Ii) reacting the purified hydrogen with chlorine at a temperature in the range of 1,200 to 1,400 ° C. to synthesize hydrogen chloride, wherein the hydrogen is added in an excessive molar ratio relative to chlorine; Iii) converting the hydrogen chloride into a liquid phase, and iii) purifying hydrogen chloride and separating excess hydrogen through fractional distillation.

Anhydrous hydrogen chloride (HCl), also called anhydrous hydrochloric acid, has a molecular weight of 36.47 and exists in a gaseous state at room temperature and normal pressure, and is a compound liquefied at atmospheric pressure of -85 ° C. Hydrogen chloride is used to manufacture various chemicals such as pharmaceuticals and dye intermediates, and high purity hydrogen chloride is a gas that is usefully used in semiconductor manufacturing processes.

In the present specification, the expression of hydrogen chloride refers to 'hydrochloric acid' in a gaseous or liquid state, and hydrochloric acid refers to an aqueous solution of 35 to 37% by weight of the hydrogen chloride. In addition, unless specified otherwise in this specification, 'high purity hydrogen chloride' refers to hydrogen chloride of 3N or more, generally 3N ~ 6N (99.9% ~ 99.9999%) grade, the expression of 'hydrogen hydrogen' and 'hydrochlorine' Means hydrogen (crude H2) and chlorine (crude Cl2) before purification, and the expressions 'hydrogen' and 'chlorine' refer to purified hydrogen and chlorine or hydrogen and chlorine elements in the mixture.

The synthesis of hydrogen chloride is usually made by reacting crude chlorine (crude Cl ₂ ) and crude hydrogen (crude H ₂ ) generated by electrolysis of brine at a high temperature of 1,200 ~ 1,300 ° C.

H ₂ + Cl ₂ ---> 2HCl + 44,000Kcal ----- ①

Cooling and absorbing the HCl gas obtained in this reaction in water produces 35-37% hydrochloric acid. Conventional hydrochloric acid production is a wet method, heating 35-37% hydrochloric acid in an evaporation tube to generate hydrogen chloride gas, which is dehydrated. dry. After cooling the tablet and compressing cooling to produce liquefied hydrogen chloride, there is a problem that the maintenance cost and a large amount of steam is required as the hydrochloric acid is handled at a high temperature.

If the HCl gas produced in Scheme ① can be compressed and cooled, it will be easier to produce anhydrous hydrogen chloride. However, the crude hydrogen (crude H2) that is usually generated in the electrolysis process of brine contains a large amount of water, and the crude chlorine (crude Cl ₂ ) produced in the general electrolytic cell contains oxygen (O ₂ ), nitrogen (N ₂ ), It is about 99.8% pure containing carbon dioxide (CO ₂ ), moisture (H ₂ O), and metals. Among these impurities, the hydrogen chloride compression and liquefaction process is hindered by water and oxygen, and the water is directly converted into oxygen, and the oxygen is converted into water during the hydrogen chloride synthesis process, making it difficult to operate equipment such as a compressor. Therefore, if only moisture and oxygen are removed from the raw materials, there is no problem in the use of the compressor of hydrogen chloride, and thus it is possible to manufacture hydrogen chloride with a low purity of 3N or lower. However, in order to manufacture high purity hydrogen chloride (99.999% or more) for semiconductors, it is necessary to remove not only moisture and oxygen but also other impurities. In particular, carbon dioxide gas is almost impossible to be separated once mixed with hydrogen chloride gas.

Accordingly, an object of the present invention is to provide a simpler and more economical method for producing dry high purity hydrogen chloride which can replace the existing wet process starting from hydrochloric acid in producing high purity hydrogen chloride.

In order to solve the above technical problem, the present invention comprises the steps of: i) purifying crude hydrogen and crude chlorine, respectively, with a purity of 99.999% or more; Ii) reacting the purified hydrogen with chlorine at a temperature in the range of 1,200 to 1,400 ° C. to synthesize hydrogen chloride, wherein the hydrogen is added in an excessive molar ratio relative to chlorine; Iii) compressing the hydrogen chloride to convert it into a liquid phase, and iii) purifying hydrogen chloride through fractional distillation and separating excess hydrogen.

In addition, the present invention is the purification of hydrogen includes the step of removing water and oxygen using a catalyst and an adsorbent of 95 to 96% level of hydrogen from the brine electrolysis process, the purification of the crude chlorine It provides a high-purity hydrogen chloride production method characterized in that the removal of the water by the first adsorption of the gas and the removal of the metal component by the first low temperature distillation to remove the gas component in the second low temperature distillation.

In addition, the present invention provides a high-purity hydrogen chloride production method characterized in that the hydrogen is added in an excess of 10 to 20 mol% in molar ratio compared to chlorine.

In addition, the present invention is a hydrogen and chlorine supply pipe purified with a purity of 99.999% or more, respectively; A reactor for synthesizing hydrogen chloride by reacting hydrogen and chlorine supplied from the hydrogen and chlorine supply pipes; A compressor for compressing and liquefying the hydrogen chloride; Fractional distillation provides a high purity hydrogen chloride production system including a distillation column for purification of the hydrogen chloride and separation and removal of unreacted hydrogen.

In addition, the present invention provides a high-purity hydrogen chloride production system characterized in that the cooling device is further added to the front or rear of the compressor.

The present invention also provides a high-purity hydrogen chloride production system, characterized in that the compressor or distillation column is composed of two or more stages.

In another aspect, the present invention provides a high-purity hydrogen chloride production system further comprising a cooling absorption tower that is dissolved in ultrapure water without compression to produce hydrochloric acid.

In addition, the present invention is for the purification of the chlorine in front of the chlorine supply pipe, the adsorption tube for removing water from the crude chlorine gas, the primary low-temperature distillation tube for removing metal components, and the primary low-temperature distillation tube Provided is a high purity hydrogen chloride production system further comprising a chlorine purification system including a cooler for cooling the distilled chlorine and a secondary low temperature distillation tube for removing gas components.

Hydrogen chloride production method and production system of the present invention is a completely hermetic dry method by directly reacting hydrogen and chlorine to synthesize hydrogen chloride immediately after compression cooling and removal of excess hydrogen, etc. in a simple distillation column is very easy to remove high purity hydrogen chloride up to 3N ~ 6N It can be manufactured, compared to the existing method, the process is simpler, easier to automate, and the energy consumption can be drastically reduced.

1 is an understanding showing an example of a high purity hydrogen chloride production system of the present invention
2 is an illustration of a chlorine purification system for removing impurities from raw crude chlorine gas

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The high purity hydrogen chloride production method of the present invention comprises the steps of: i) purifying crude hydrogen and crude chlorine as raw materials, each having a purity of 99.999% or more; Ii) reacting the purified hydrogen with chlorine at a temperature in the range of 1,200 to 1,400 ° C. to synthesize hydrogen chloride, wherein the hydrogen is added in an excessive molar ratio relative to chlorine; Iii) converting the hydrogen chloride into a liquid phase, and iii) purifying hydrogen chloride and separating excess hydrogen through fractional distillation.

As described above, the crude hydrogen (crude H2) gas from the brine electrolysis process is only 95 to 96% purity, and the crude chlorine (crude Cl ₂ ) produced in the general electrolytic cell contains oxygen (O ₂ ) and nitrogen. (N ₂ ), carbon dioxide (CO ₂ ), water (H ₂ O) and a metal component containing a purity of about 99.8%. In the present invention, the hydrogen and oxygen may be removed using a catalyst and an adsorbent with respect to the hydrogen to have a purity of 99.9999% or more. 2 is an illustration of a chlorine purification system for removing impurities from raw crude chlorine gas. As can be seen in Figure 2, the chlorine purification system is the adsorption tube for the removal of water from the crude chlorine gas, the primary low-temperature distillation tube for removing metal components, the chlorine distilled in the primary low-temperature distillation tube And a second low temperature distillation tube for removing the gas component and a cooler for cooling the gas. Using the chlorine purification system, the crude chlorine gas of 99% to 99.9% passes through the adsorption tube, removes moisture, and removes metal components such as iron, chromium, and nickel at the first low temperature distillation (temperature -25 ° C to 15 ° C). After removal, the secondary low temperature distillation (temperature -35 ℃ ~ 5 ℃) can make more than 99.9999% purity by removing gaseous components such as carbon dioxide, nitrogen and oxygen.

1 is an understanding showing an example of a high purity hydrogen chloride production system of the present invention. As shown in Fig. 1, the high purity hydrogen chloride production system of the present invention comprises: a hydrogen and chlorine supply pipe for supplying purified hydrogen and chlorine with a purity of 99.999% or more, respectively; A reactor for synthesizing hydrogen chloride by reacting hydrogen and chlorine supplied from the hydrogen and chlorine supply pipes; A compressor for compressing and liquefying the hydrogen chloride; Distillation column for the purification of the liquefied hydrogen chloride and the separation and removal of unreacted hydrogen through fractional distillation.

In addition, the high-purity hydrogen chloride production system of the present invention is for the purification of the chlorine in front of the chlorine supply pipe, the adsorption tube for the removal of water in chlorine gas of 99.8% purity, and the first low temperature distillation tube for removing metal components and The chlorine purification system may further include a cooler for cooling the chlorine distilled in the first low temperature distillation tube and a second low temperature distillation tube for removing gas components. The chlorine purification system may be used in-line with the hydrogen chloride production system of the present invention, or may exist as a separate system to store purified chlorine of high purity in a tank and supply it to the hydrogen chloride production system.

In the high-purity hydrogen chloride production system of the present invention, chlorine and hydrogen as raw materials are controlled by FCV (flow proportional control valve), and hydrogen is maintained in an excess of 10 to 20 mol% relative to the theoretical amount. In the reaction of hydrogen and chlorine, the hydrogen is preferably added in excess of chlorine. The reaction for producing hydrogen chloride by the reaction of hydrogen and chlorine should theoretically be carried out in a mol ratio of 1: 1, but if chlorine remains as an unreacted starting material, separation from hydrogen chloride is not easy and damage of the reaction system due to chlorine toxicity This is because there is a risk of causing. Therefore, the hydrogen is preferably in an excess of 10 mol% to 20 mol% relative to chlorine in the reaction of hydrogen and chlorine.

The reactor is made of graphite (Graphite) is a material that is not affected by the raw material chlorine or hydrogen chloride at high temperature, the compressor is preferably made of a special material that can withstand hydrogen chloride. Preferably, the compressor is a reciprocating two-stage or more multistage compressor. In addition, it is preferable that a cooling device is further added to the front or rear of the compressor in order to increase the compression efficiency. The operating temperature of the reactor is operated in the range of 1,200 to 1,400 ° C., and preferably maintained at 1,300 ± 50 ° C., in order to maintain the temperature, hydrogen is first combusted by heating with air, and the moisture generated from the reaction is generated in the initial stage of synthesis. The gas was absorbed and removed with hydrochloric acid. After the initial reaction, the temperature of the reactor can be maintained by the heat of reaction.

After the reaction, some of the surplus hydrogen is vented appropriately before and after passing through the chiller to increase the cooling efficiency, and once liquefied hydrogen chloride is removed from the liquefied hydrogen chloride through fractional distillation to remove metals and the like. The reaction hydrogen is further separated off. Through this multi-stage distillation column, some residual impurities such as hydrogen may be removed from the top to produce high purity hydrogen chloride of 6N or more. This is because the liquefied hydrogen chloride contains a small amount of hydrogen by partial pressure, and hydrogen may act as an impurity depending on the process of use, so it is preferable to completely distill the liquefied hydrogen chloride in a distillation column to completely remove residual hydrogen. In the high purity hydrogen chloride production system of the present invention, the compressor or distillation column is preferably composed of two or more stages for efficiency. Hydrogen chloride that has been fractionated in the distillation column is stored in the hydrogen chloride tank 30 for storing the purified liquid hydrogen chloride.

In addition, the high-purity hydrogen chloride production system of the present invention further includes a cooling absorption tower to produce a high purity 37-38% hydrochloric acid of 5N (99.999%) or more by dissolving a portion of the ultra-pure water before liquefying the synthesis gas in order to reconsider economy. can do.

In this case, 3N (99.9%) to 6N (99.9999%) of hydrogen chloride or hydrochloric acid may be produced according to the degree of purification of raw materials and products, and the process may be simpler and energy demand may be drastically reduced than conventional wet methods.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the following examples are merely to help the understanding of the present invention is not limited to the following examples.

Example

In the embodiment of the present invention, the reactor 10 for reacting the previously purified high-purity hydrogen and chlorine, the compressor 20 for cooling and compressing the hydrogen chloride gas reacted through the reactor, and for cooling the hydrogen chloride through the compressor Cooling apparatus 21, a hydrochloric acid tank 60 for dissolving hydrogen chloride passed through the compressor in de-ionized water to produce and store hydrochloric acid with high purity, and fractional distillation of hydrogen chloride liquefied in the compressor. A high-purity hydrogen chloride production system including a two-stage distillation column (ie, a first distillation column 40 and a second distillation column 50) for removing unreacted hydrogen and the like, and a hydrogen chloride tank 30 storing liquid hydrogen chloride purified from the distillation column. Hydrogen chloride was prepared. First, hydrogen and chlorine were introduced into the reactor at a molar ratio of about 15% relative to chlorine at a level of about 80 and 70 m 3 / hr, respectively, and the reactor was maintained at about 1,300 ° C. The synthesized hydrogen chloride had an outlet temperature of about 160 to 165 ° C. in the compressor, liquefied by cooling to about −20 ° C. using a cooling device, and cooled to about −40 ° C. through a distillation column.

Table 1 summarizes the results of quantifying purity and impurities of hydrogen chloride and crude chlorine as raw materials in the present invention, purified hydrogen and chlorine after purification, reactors, compressors, and distillation towers, and Table 2 below. The results of quantifying the purity and impurity of hydrochloric acid prepared by using a high purity hydrogen chloride production system of the hydrochloric acid prepared in an aqueous solution state through a cooling absorption tower. As can be seen in Table 1 and Table 2, it can be seen that the hydrogen chloride prepared using the high purity hydrogen chloride production system of the present invention has a purity of 5N to 6N (99.999 to 99.9999%) or more.

division Raw material Raw Material Purification synthesis refine Storage tank crude H ₂ crude Cl ₂ H ₂ Cl ₂ HCl HCl HCl Purity 95%-96% 99.8% 99.999% 99.9995% 99.995% 99.999% to 99.9999% 99.999% to 99.9999% impurities O ₂ ≤10ppm ≤500ppm ≤2ppm ≤0.5ppm ≤1 ppm ≤1 ppm ≤1 ppm N ₂ - ≤1 ppm ≤1 ppm ≤1 ppm ≤1 ppm ≤1 ppm CO - ≤1 ppm ≤0.5ppm ≤0.5ppm ≤0.5ppm ≤0.5ppm CO ₂ - ≤1 ppm ≤0.5ppm ≤0.5ppm ≤1 ppm ≤1 ppm CH ₄ - ≤1 ppm ≤0.5ppm ≤1 ppm - - H ₂ O ≤40,000ppm ≤5ppm ≤4ppm ≤1 ppm ≤1 ppm ≤1 ppm ≤1 ppm

division 37% HCl Mixing 37% HCl Storage Tank HCl DI Water 37% HCl Purity 99.999% to 99.9999% 18 MΩcm or more 36%-38% impurities O2 ≤1 ppm - NH4 ≤0.5ppm N2 ≤1 ppm SO4 ≤0.5ppm CO ≤0.5ppm PO4 ≤0.05ppm CO2 ≤1 ppm Residue on Ignition ≤3ppm CH4 - Total metal ≤1,000 ppb H2O ≤1 ppm

The embodiments of the present invention described above should not be construed as limiting the technical idea of the present invention. The scope of protection of the present invention is limited only by the matters described in the claims, and those skilled in the art will be able to modify the technical idea of the present invention in various forms. Accordingly, such improvements and modifications will fall within the scope of the present invention as long as they are obvious to those skilled in the art.

10: HCl synthesis reactor 20: compressor
21: cooling device 30: hydrogen chloride tank
40: HCl first distillation tower 50: HCl second distillation tower
60: hydrochloric acid tank 70: primary low temperature distillation tube
80: Cl2 cooler 90: Secondary low temperature distillation tube

Claims (8)

As a method for producing high purity hydrogen chloride by synthesizing hydrogen chloride by reacting crude hydrogen and crude chlorine as raw materials, and then compression cooling.
Iii) a hydrogen purification step of producing purified hydrogen by performing a removal process for water and oxygen contained in the hydrogen hydrogen;
Ii) a chlorine purification step of performing purified chlorine to remove water and oxygen contained in the crude chlorine to produce purified chlorine;
Iii) reacting the purified hydrogen with the purified chlorine to synthesize hydrogen chloride; And
Iii) a high purity hydrogen chloride production method comprising a compression cooling step of compressing and cooling the hydrogen chloride synthesized through the reaction step. The method of claim 1,
The hydrogen purification step includes removing hydrogen and hydrogen using a catalyst and an adsorbent for hydrogen hydrogen, and the chlorine purification step removes moisture by primary adsorption of crude chlorine gas, and the metal component by primary low temperature distillation. After removal of the second low temperature distillation, high-purity hydrogen chloride production method characterized in that it was carried out by removing gas components other than chlorine gas. The method of claim 1,
In the reaction step, hydrogen is a high-purity hydrogen chloride production method characterized in that the input in excess of 10 to 20 mol% in molar ratio compared to chlorine. Hydrogen purification device for producing purified hydrogen by performing a process for removing water and oxygen contained in the hydrogen;
Chlorine purification device for producing purified chlorine by performing a process for removing water and oxygen contained in the crude chlorine;
A reactor for synthesizing hydrogen chloride by reacting hydrogen produced from the hydrogen purification device with chlorine produced from the chlorine purification device;
A compressor for compressing the hydrogen chloride synthesized in the reactor; And
High purity hydrogen chloride production system comprising a cooling device for cooling the hydrogen chloride compressed by the compressor. 5. The method of claim 4,
High purity hydrogen chloride production system characterized in that the cooling device is further added to the front or rear of the compressor. 5. The method of claim 4,
High-purity hydrogen chloride production system, characterized in that the compressor or distillation column is composed of two or more stages. 5. The method of claim 4,
A high purity hydrogen chloride production system further comprising a cooling absorption tower for dissolving the hydrogen chloride derived from the compressor without purification to produce hydrochloric acid. 5. The method of claim 4,
The chlorine purification apparatus includes an adsorption tube for removing water from the crude chlorine gas, a primary low temperature distillation tube for removing metal components, a cooler for cooling chlorine distilled in the primary low temperature distillation tube, and other than chlorine. A high purity hydrogen chloride production system comprising a secondary low temperature distillation tube for removing gas components.

Images