Purification process and production process of electronic-grade high-purity acetylene

Abstract

The invention relates to the technical field of acetylene gas purification, in particular to an electronic-grade high-purity acetylene purification process and a production process thereof. The electronic-grade high-purity acetylene purification process comprises the following steps: preparing an acetylene gas raw material into an acetylene hydrate, heating and / or depressurizing the acetylene hydrate to enable the acetylene hydrate to release acetylene gas, and purifying and collecting the acetylene gas. The acetylene hydrate is synthesized to release acetylene gas, the electronic-grade high-purity acetylene is obtained after water removal, the process steps are simplified, the use amount of materials used in the purification process is low, and the high-purity acetylene can be obtained at low cost.

Description

Technical Field

[0001] The invention relates to the technical field of acetylene gas purification, and in particular to an electronic grade high-purity acetylene purification process and a production process thereof. Background Art

[0002] High-purity acetylene can be used to construct carbon masks in the photolithography process of integrated circuits. This carbon mask is an important material for producing semiconductors, so high-purity acetylene has good commercial prospects in the semiconductor industry. At present, there are two main methods for industrial production of acetylene: the calcium carbide method and the natural gas cracking method. Then, it is purified through the purification process of sodium hypochlorite solution to obtain industrial-grade acetylene that meets the standards. However, the carbon mask production process has extremely stringent requirements on the purity of acetylene. The purity of industrial acetylene (98%) is far from meeting the process conditions. Only electronic grade (4N) high-purity acetylene with a purity of more than 99.99% can meet the requirements.

[0003] In order to meet the market demand for electronic-grade acetylene, a variety of acetylene gas purification processes have emerged in the industry. For example, CN104496740 A discloses a device and a purification method for purifying industrial acetylene into high-purity acetylene. After industrial acetylene is adsorbed by three adsorption towers, 3.5N high-purity acetylene is obtained, but the purity of the obtained acetylene does not reach the electronic grade. CN 214937122 U discloses a purification system for electronic-grade purity acetylene. After acetylene raw gas is absorbed and adsorbed by an absorption tower and an adsorption tower, electronic-grade (4N) acetylene is obtained through analysis and high-pressure drying. However, the absorption and adsorption process consumes a large amount of chemical agents, and the analysis and drying process equipment and operations are numerous and the process is complicated. Therefore, a process technology with streamlined process and low resource consumption is needed to obtain electronic-grade high-purity acetylene. Summary of the invention

[0004] In order to overcome the deficiencies mentioned in the background technology, the present invention provides a purification process for electronic grade high-purity acetylene.

[0005] The technical solution of the present invention comprises the following steps:

[0006] 1) Firstly, acetylene gas raw material is made into acetylene hydrate;

[0007] 2) raising the temperature and / or reducing the pressure of the acetylene hydrate to allow the acetylene hydrate to release acetylene gas;

[0008] 3) Purifying and collecting the acetylene gas.

[0009] In step 1), the acetylene gas raw material comes from an industrial acetylene gas cylinder or directly from the compression section of an acetylene production line. After the acetylene raw material gas is alkaline-washed by a pre-treatment device, the acetylene gas raw material is sent to a hydration kettle.

[0010] Furthermore, the acetylene gas raw material and water are combined into acetylene hydrate in the hydration kettle. As the acetylene hydrate is continuously formed, the pressure in the hydration kettle will continue to decrease. The acetylene gas raw material is continuously introduced and the water injection of the stabilizer cooperates to stabilize the internal pressure of the hydration kettle.

[0011] Furthermore, in the hydration kettle, the temperature of generating the acetylene hydrate is stabilized at 0-10° C., and the pressure is stabilized at 1.0-2.0 MPa.

[0012] Furthermore, the hydration kettle is provided with a jacket, antifreeze may be contained in the hydration kettle, an overflow is installed at the top of the hydration kettle, and a voltage stabilizer is connected to the bottom of the hydration kettle.

[0013] Furthermore, the hydration kettle jacket is connected to a cold or hot source for lowering or raising the temperature in the hydration kettle, with the gravity direction being downward, and the cold or hot source entering and exiting in a bottom-in and top-out manner.

[0014] Furthermore, the cold source is ethylene glycol.

[0015] Furthermore, the antifreeze solution is one or more of ethylene glycol and calcium chloride solution.

[0016] Further, the addition of the antifreeze solution depends on the operating temperature.

[0017] Furthermore, the overflow device is used to observe the fullness of the liquid in the hydration kettle.

[0018] Furthermore, the overflow is provided with a vent valve, and the vent valve is used to remove impurity gas.

[0019] Furthermore, the pressure stabilizer is used to balance the pressure in the hydration kettle.

[0020] In step 2), before the acetylene hydrate releases the acetylene gas, the pressure regulator is used to inject water into the hydration kettle to remove the remaining gas in the hydration kettle until liquid flows out of the overflow, the overflow is closed, the vent valve is closed, and then the acetylene hydrate is depressurized and / or heated to release the acetylene gas.

[0021] In step 3), the acetylene gas released from the acetylene hydrate is sequentially dehydrated and purified in a condenser and a dryer, and then compressed, filtered and loaded into a gas cylinder.

[0022] Furthermore, the dryer is one or more of anhydrous calcium chloride and 3A molecular sieve.

[0023] Furthermore, the filtering is to filter out solid impurities in the gas.

[0024] The beneficial effects of the present invention are:

[0025] 1. The present invention utilizes acetylene hydrate to release acetylene gas to obtain high-purity acetylene, requires less equipment for purification, has simple operating conditions and high working efficiency.

[0026] 2. The acetylene purification process provided by the present invention uses less materials in the purification process and has low cost.

[0027] 3. The electronic grade high-purity acetylene purified by the present invention has a high purity, which can reach 99.9999%. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The accompanying drawing is a schematic diagram of the process flow of producing electronic grade high-purity acetylene by hydration of acetylene according to the present invention.

[0029] Description of the accompanying figures: 1-preprocessor, 2-hydration kettle, 3-pressure regulator, 4-condenser, 5-dryer, 6-compressor, 7-filter, 21-pressure control valve, 22-overflow, 23-vent valve Specific embodiments

[0030] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. The embodiments of the present invention involved in the following description are usually only part of the embodiments of the present invention, rather than all of the embodiments. Those skilled in the art can completely combine the embodiments of the present invention to obtain other embodiments without creative work, and these embodiments are also within the scope of protection of the present invention.

[0031] The invention enlightenment of the present invention is:

[0032] In the acetylene production process, it is necessary to remove water from acetylene gas to prevent water from forming acetylene hydrate with acetylene gas. The formation of acetylene hydrate is related to temperature and pressure in addition to water. The formation conditions of hydrate are shown in Table 1 below.

[0033] Table 1

[0034] Pressure / MPag 0.588 0.784 0.98 1.17 1.47 1.96 2.45 2.94 Limit temperature / ℃ 2 4 6 8 10 12 13.5 15

[0035] Acetylene hydrate will release high-purity acetylene under non-equilibrium pressure and temperature conditions. Therefore, a process for producing electronic-grade high-purity acetylene using acetylene hydrate has been designed. Compared with the existing technology, its equipment and process equipment are streamlined, the process operation is simple, the amount of chemical agents used is small, the cost is low, and most importantly, the purity of the purified acetylene gas can reach 99.9999%.

[0036] Figure 1 This is a diagram of the process equipment of the present invention.

[0037] The technical equipment for realizing the present invention includes: a preprocessor 1, a hydration kettle 2, a voltage stabilizer 3, a condenser 4, a dryer 5, a compressor 6, and a filter 7. The preprocessor 1 is connected to the hydration kettle 2 by a pipeline. A flow meter is provided between the preprocessor 1 and the hydration kettle 2 to control the gas flow. The hydration kettle 2 is provided with a jacket for containing a heat transfer liquid for heating or cooling the hydration kettle 2. A pressure control valve 21 is provided below the hydration kettle 2 to reduce the pressure in the hydration kettle 2. An overflow 22 and a vent valve 23 are provided above the hydration kettle 2. The overflow 22 is used to observe the fullness of the liquid in the hydration kettle 2. The vent valve 23 is provided above the hydration kettle 2. 3 is used to release excess impurities. The stabilizer 3 is connected to the bottom of the hydration kettle alone. The stabilizer 3 balances the internal pressure of the hydration kettle 2 by injecting water into the hydration kettle 2. The condenser 4 is connected to the hydration kettle 2 by a pipeline and is used to condense the moisture entrained by the high-purity acetylene released in the hydration kettle 2. The dryer 5 is connected to the condenser 4 by a pipeline and is used to obtain dry high-purity acetylene. The compressor 6 is connected to the dryer 5 by a pipeline. The filter 7 is connected to the compressor 6 by a pipeline. The compressor 6 and the filter 7 are used to compress the dried high-purity acetylene, filter the particulate impurities therein, and then fill it into the acetylene cylinder.

[0038] Example 1

[0039] like Figure 1 As shown, a purification process for electronic grade high-purity acetylene comprises the following steps:

[0040] 1. Use industrial acetylene (99.45%) as the acetylene gas raw material, pass the acetylene gas raw material into a pre-treatment device filled with NaOH solution, and wash away the entrained solvent and carbon dioxide gas in the acetylene gas raw material;

[0041] 2. Add 1m3 of 15% ethylene glycol into the hydration kettle. 3 Solution, the jacket of the hydration kettle is introduced with a cold source refrigerant ethylene glycol solution, and the ethylene glycol solution in the jacket is used to control the temperature in the hydration kettle to be maintained at 0-5°C;

[0042] 3. The acetylene gas raw material washed by the pretreatment device is introduced into the hydration kettle. The acetylene gas raw material reacts with water in the hydration kettle to generate acetylene hydrate. As the acetylene hydrate in the hydration kettle is generated, the pressure in the kettle becomes lower and lower. The acetylene gas raw material is continuously added into the hydration kettle. When the pressure in the hydration kettle no longer decreases, the acetylene hydrate in the hydration kettle is in a supersaturated state. Subsequently, a pressurizer is used to inject water to continue to react with the acetylene gas raw material to stabilize the pressure in the hydration kettle until the pressure in the hydration kettle is constant at 1.5 MPa when no acetylene gas raw material is introduced and no pressurizer is used to inject water, and the hydration reaction is terminated.

[0043] 4. Use the voltage stabilizer to inject water into the hydration kettle again to discharge the impurities inside the hydration kettle, until liquid flows out of the overflow device above the hydration kettle, close the vent valve and stop injecting water;

[0044] 5. A heat source is introduced into the jacket of the hydration kettle to raise the temperature of the hydration kettle to 8-10°C. A pressure control valve is used to reduce the pressure in the hydration kettle to 0.5-0.6Mpa to release high-purity acetylene from acetylene hydrate. The high-purity acetylene enters the condenser through a pipeline, and the entrained water is condensed and separated. Then, the high-purity acetylene is introduced into a dryer to obtain dry high-purity acetylene. The desiccant in the dryer is a 3A molecular sieve. The high-purity acetylene is then introduced into a compressor for compression. After the solid particles entrained in the high-purity acetylene are filtered out by a filter, electronic grade high-purity acetylene (99.998%) is obtained. Finally, the acetylene is introduced into an acetylene cylinder. The moisture content of the collected high-purity acetylene is analyzed using a dew point meter. The gas impurity components are analyzed using a gas chromatograph. The results are as shown in Table 2:

[0045] Table 2

[0046]

[0047] Example 2

[0048] like Figure 1 As shown, a purification process for electronic grade high-purity acetylene comprises the following steps:

[0049] 1. Use industrial acetylene (99.51%) as the acetylene gas raw material, pass the acetylene gas raw material into a pre-treatment device filled with NaOH solution, and wash away the entrained solvent and carbon dioxide gas in the acetylene gas raw material;

[0050] 2. Pass 1m3 of 10% calcium chloride into the hydration kettle. 3 Solution, the jacket of the hydration kettle is introduced with a cold source refrigerant ethylene glycol solution, and the ethylene glycol solution in the jacket is used to control the temperature in the hydration kettle to be maintained at 0-5°C;

[0051] 3. The acetylene gas raw material washed by the pretreatment device is introduced into the hydration kettle. The acetylene gas raw material reacts with water in the hydration kettle to generate acetylene hydrate. As the acetylene hydrate in the hydration kettle is generated, the pressure in the kettle becomes lower and lower. The acetylene gas raw material is continuously added into the hydration kettle. When the pressure in the hydration kettle no longer decreases, the acetylene hydrate in the hydration kettle is in a supersaturated state. Subsequently, a pressurizer is used to inject water to continue to react with the acetylene gas raw material to stabilize the pressure in the hydration kettle until the pressure in the hydration kettle is constant at 1.0 MPa when no acetylene gas raw material is introduced and no pressurizer is used to inject water, and the hydration reaction is terminated.

[0052] 4. Use the voltage stabilizer to inject water into the hydration kettle again to discharge the impurities inside the hydration kettle, until liquid flows out of the overflow device above the hydration kettle, close the vent valve and stop injecting water;

[0053] 5. A heat source is introduced into the jacket of the hydration kettle to raise the temperature of the hydration kettle to 13-15° C. A pressure control valve is used to reduce the pressure in the hydration kettle to 0.6-0.7 MPa to release high-purity acetylene from acetylene hydrate. The high-purity acetylene enters the condenser through a pipeline to condense and separate the entrained water. The high-purity acetylene is then introduced into a dryer to obtain dry high-purity acetylene. The desiccant in the dryer is a 3A molecular sieve. The high-purity acetylene is then introduced into a compressor for compression. After the solid particles entrained in the high-purity acetylene are filtered out by a filter, electronic grade high-purity acetylene (99.9993%) is obtained. Finally, the acetylene is introduced into an acetylene cylinder. The moisture content of the collected high-purity acetylene is analyzed using a dew point meter. The gas impurity components are analyzed using a gas chromatograph. The results are as shown in Table 3 below:

[0054] Table 3

[0055]

[0056] Best Practice 3

[0057] like Figure 1 As shown, a purification process for electronic grade high-purity acetylene comprises the following steps:

[0058] 1. Use industrial acetylene (99.45%) as the acetylene gas raw material, pass the acetylene gas raw material into a pre-treatment device filled with NaOH solution, and wash away the entrained solvent and carbon dioxide gas in the acetylene gas raw material;

[0059] 2. Add 1m3 of 15% ethylene glycol or 10% calcium chloride into the hydration kettle. 3 Solution, the cold source refrigerant ethylene glycol solution is introduced into the jacket of the hydration kettle, and the ethylene glycol solution in the jacket is used to control the temperature in the hydration kettle to be maintained at 2-3°C;

[0060] 3. The acetylene gas raw material washed by the pretreatment device is introduced into the hydration kettle. The acetylene gas raw material reacts with water in the reactor to generate acetylene hydrate. As the acetylene hydrate in the reactor is generated, the pressure in the reactor becomes lower and lower. The acetylene gas raw material is continuously added into the hydration kettle. When the pressure in the hydration kettle no longer decreases, the acetylene hydrate in the hydration kettle is in a supersaturated state. Then, a pressurizer is used to inject water to continue to react with the acetylene gas raw material to stabilize the pressure in the hydration kettle until the pressure in the hydration kettle is constant at 0.8-2.0Mpa when no acetylene gas raw material is introduced and no pressurizer is used to inject water, and the hydration reaction is terminated.

[0061] 4. Use the voltage stabilizer to inject water into the hydration kettle again to discharge the impurities inside the hydration kettle, until liquid flows out of the overflow device above the hydration kettle, close the vent valve and stop injecting water;

[0062] 5. A heat source is introduced into the jacket of the hydration kettle to raise the temperature of the hydration kettle to 16-18° C. A pressure control valve is used to reduce the pressure in the hydration kettle to 1.0-1.1 MPa to release high-purity acetylene from acetylene hydrate. The high-purity acetylene enters the condenser through a pipeline, and the entrained water is condensed and separated. The high-purity acetylene is then introduced into a dryer to obtain dry high-purity acetylene. The desiccant in the dryer is a 3A molecular sieve. The high-purity acetylene is then introduced into a compressor for compression. After the solid particles entrained in the high-purity acetylene are filtered out by a filter, electronic grade high-purity acetylene (99.9999%) is obtained. Finally, the acetylene is introduced into an acetylene cylinder. The water content of the collected high-purity acetylene is analyzed using a dew point meter. The gas impurity components are analyzed using a gas chromatograph. The results are as shown in Table 4:

[0063] Table 4

[0064]

[0065] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A purification process for electronic grade high-purity acetylene, characterized in that: Firstly, acetylene gas raw material is made into acetylene hydrate, then the temperature and / or pressure of the acetylene hydrate are increased and / or reduced to make the acetylene hydrate release acetylene gas, and the acetylene gas is purified and collected.

2. The purification process of electronic grade high-purity acetylene as claimed in claim 1, characterized in that: Before preparing the acetylene hydrate, the acetylene gas raw material is first passed into an alkaline solution for washing and removing impurities.

3. The purification process of electronic grade high-purity acetylene as claimed in claim 1, characterized in that Before the acetylene hydrate releases acetylene gas, impurities need to be removed.

4. The purification process of electronic grade high-purity acetylene as claimed in claim 1, characterized in that: The step of purifying and collecting the acetylene gas includes condensing, drying, compressing and filtering the acetylene gas.

5. A production process for electronic grade high purity acetylene, characterized in that The method comprises the acetylene purification process as claimed in any one of claims 1 to 4, and then pressurizing and bottling the purified acetylene gas.

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