阅读说明：本技术 一种4n电子级乙炔提纯装置及提纯工艺 (4N electronic-grade acetylene purification device and purification process ) 是由 温海涛 汪民霞 陈剑军 王新喜 徐聪 于 2021-08-23 设计创作，主要内容包括：本发明公开了一种本发明提供了一种4N电子级乙炔提纯装置及提纯工艺,提纯装置包括吸附塔、低压压缩机、吸收塔和解析塔,吸附塔下侧设有输入端,上侧设有输出端,低压压缩机连接吸附塔与吸收塔,吸收塔上方具有一可通入吸收溶剂的通入口,吸收塔顶部用于排出溶解度较小的轻组分杂质并将其排出,吸收塔底部为吸收乙炔及重组分杂质的吸收溶剂且其通过吸收塔釜泵进入解析塔中,解析塔,用于从进入其中的吸收溶剂中将乙炔解析出来。本申请根据乙炔与部分杂质的吸附特性不同采用吸附分离方法分离提纯乙炔,并根据乙炔中轻组分和重组分杂质组分与乙炔在溶剂中溶解度的不同采用吸收解析的方法进行分离提纯乙炔,可以得到4N电子级乙炔产品。(The invention discloses a 4N electronic-grade acetylene purification device and a purification process, wherein the purification device comprises an adsorption tower, a low-pressure compressor, an absorption tower and an analysis tower, an input end is arranged at the lower side of the adsorption tower, an output end is arranged at the upper side of the adsorption tower, the low-pressure compressor is connected with the adsorption tower and the absorption tower, an inlet through which an absorption solvent can be introduced is arranged above the absorption tower, the top of the absorption tower is used for discharging light-component impurities with low solubility and discharging the light-component impurities, the bottom of the absorption tower is used for absorbing the absorption solvent of acetylene and heavy-component impurities and enters the analysis tower through an absorption tower kettle pump, and the analysis tower is used for analyzing the acetylene from the absorption solvent entering the analysis tower. The method adopts an adsorption separation method to separate and purify acetylene according to different adsorption characteristics of acetylene and partial impurities, and adopts an absorption and desorption method to separate and purify acetylene according to different solubilities of light component and heavy component impurity components in acetylene and acetylene in a solvent, so that a 4N electronic-grade acetylene product can be obtained.)

1. The utility model provides a 4N electronic grade acetylene purification device to natural gas schizolysis acetylene is as acetylene raw materials which characterized in that includes:

the lower side of the adsorption tower is provided with an input end, and the upper side of the adsorption tower is provided with an output end for removing carbon dioxide in the acetylene raw material;

the low-pressure compressor is connected with the adsorption tower and the absorption tower and is used for compressing the acetylene raw material in the adsorption tower and sending the acetylene raw material into the absorption tower;

an inlet opening for introducing an absorption solvent is arranged above the absorption tower, the top of the absorption tower is used for discharging light component impurities with low solubility and discharging the light component impurities to a tail gas treatment unit, the bottom of the absorption tower is provided with an absorption solvent for absorbing acetylene and heavy component impurities, the absorption solvent enters the desorption tower through an absorption tower kettle pump, the purity of the absorption solvent is 4N level, and wherein the water content is less than 10ppm, the absorption solvent is a combination of any two or more of methanol, ethanol, ethylene glycol or tetrahydrofuran, the absorption solvent is continuously introduced into the absorption tower from the inlet, the introduction flow rate is 1-3kg/h, the temperature of the absorption solvent is-60 to-50 ℃, the pressure is 6 to 8bar, the absorption temperature of the absorption tower is-50-0 ℃, and the absorption pressure is 5-10 bar;

the resolving tower is used for resolving acetylene from the absorption solvent entering the resolving tower, so that 4N electronic-grade acetylene is obtained and is discharged from the top of the resolving tower, and the absorption solvent with heavy component impurities dissolved is discharged from the bottom of the resolving tower; and

the bottom of the desorption tower is connected with the top of the stripping tower through a desorption tower kettle pump and is used for conveying the absorption solvent dissolved with heavy component impurities at the bottom of the desorption tower into the stripping tower, hot nitrogen is connected to the bottom of the stripping tower and is used for separating the heavy component impurities from the absorption solvent in the stripping tower, the separated absorption solvent is discharged from the bottom of the stripping tower through the stripping tower kettle pump and is recycled, and the heavy component impurities are discharged to the tail gas treatment unit.

2. The apparatus for purifying 4N electronic grade acetylene according to claim 1, wherein the top of the desorption tower is provided with a desorption tower condenser for discharging the 4N electronic grade acetylene, and the bottom of the desorption tower is provided with a desorption tower reboiler for providing ascending vapor flow into the desorption tower.

3. The purification device of 4N electronic grade acetylene according to claim 1, wherein the desorption tower condenser is connected with a high pressure compressor for compressing the discharged 4N electronic grade acetylene and loading into a product steel cylinder.

4. The device for purifying 4N electronic-grade acetylene according to claim 3, wherein a high-pressure drying tower is further included between the high-pressure compressor and the product steel cylinder for drying the 4N electronic-grade acetylene.

5. The 4N electronic grade acetylene purification device according to claim 4, wherein the dry adsorbent used for drying and dewatering in the high pressure drying tower is any one or combination of 3A molecular sieve, 4A molecular sieve, 5A molecular sieve, 13X molecular sieve, alumina or silica gel, and the particle size of the dry adsorbent is 3-5 mm.

6. The 4N electronic grade acetylene purification device according to claim 1, wherein the adsorbent used for adsorbing carbon dioxide in the adsorption tower is any one or combination of sodium hydroxide, potassium hydroxide, lithium hydroxide or calcium hydroxide, and the particle size of the adsorbent is 3-5 mm.

7. A4N electronic grade acetylene purification process is characterized in that natural gas cracking acetylene is used as an acetylene raw material, carbon dioxide in the acetylene raw material is removed, an absorption solvent is used for dissolving acetylene and heavy component impurities in the acetylene raw material, so that light component impurities with low solubility in the acetylene raw material are removed, finally the acetylene is resolved and separated from the absorption solvent, and the heavy component impurities are continuously dissolved in the absorption solvent, so that the 4N electronic grade acetylene is obtained.

Technical Field

The invention relates to the technical field of acetylene gas purification, in particular to a 4N electronic-grade acetylene purification device and a purification process.

Background

The electronic-grade (volume fraction 99.99%, 4N-grade for short) purity acetylene is mainly applied to the preparation of amorphous carbon masks in the semiconductor industry, and a plasma enhanced chemical vapor deposition process is adopted to form a stable amorphous carbon layer film and construct a carbon hard mask for a photoetching process. In addition, C of electronic grade purity₂H₂Can also be used as raw material gas of carbon in metal piece processing and low-pressure carburization process, and can be used as C in carburization process compared with C₃H₈，CH₄Isogas, C₂H₂The method has the characteristics of easy cracking at low pressure, high carbon utilization rate, difficult carbon deposition and coking and the like.

At present, acetylene has the purity of only 98-99.5 percent (volume fraction), and acetylene production mainly comprises two ways, namely a calcium carbide method and a hydrocarbon cracking method. The calcium carbide method is that crude acetylene gas prepared by the action of calcium carbide and water is purified, compressed, dried, dissolved in acetone and stored in a gas cylinder filled with porous filler, which is called dissolved acetylene gas. The dissolved acetylene has the characteristics of convenient and safe use, low calcium carbide consumption, no environmental pollution and the like, and is widely applied to the aspects of gas welding, gas cutting and the like. At present, the calcium carbide method is mostly adopted in China for production, although the concentration of acetylene gas produced by the method is high, industrial calcium carbide is impure, and when the calcium carbide reacts with water to generate the acetylene gas, impurities and water generate a plurality of side reactions to generate impurities such as phosphine, hydrogen sulfide, arsine and the like. These impurities contained in acetylene gas have the following hazards: (1) endanger safety and use; (2) influence the quality of the acetylene cylinder filler; (3) the quality of the welding seam is deteriorated; (4) error the analytical instrument; (5) the catalyst can be poisoned and can be out of work. (6) The carbon mask is a harmful impurity in the carburization process and the preparation of the amorphous carbon mask in the integrated circuit, and the quality of the carbon mask is influencedAmount of the compound (A). Therefore, these impurities in acetylene must be removed during production to be shipped. The acetylene prepared by hydrocarbon cracking is mainly prepared by natural gas cracking, the concentration of acetylene in cracked gas prepared by natural gas partial oxidation cracking is not high, the volume fraction is only 8-15%, and the rest is impurities. The impurities in the acetylene feed gas are mainly composed of hydrogen, nitrogen, oxygen, methane, carbon monoxide, ethane, ethylene, (commonly referred to as light components), carbon dioxide, propane, propylene, methylacetylene, 1, 3-butadiene, 1, 2-butadiene, vinylacetylene, ethylacetylene, C₆₊Etc. (often referred to as heavies). The impurities have great influence on the downstream processing and utilization of acetylene, the light components can reduce the acetylene conversion rate, and the heavy components are easy to deposit carbon and coke in the amorphous carbon mask and the carburizing process, so that the carbon mask deposition process cannot be carried out.

With the continuous development of the carburizing process and the semiconductor industry, in order to obtain a high-quality carbon film, higher requirements are put forward on the purity of acetylene serving as a raw material, and the impurity components in the acetylene must be reduced to the minimum degree to meet the process requirements. Because the purity of acetylene prepared by the existing calcium carbide method and natural gas cracking method can not meet the requirements of a carburizing process and the semiconductor industry on the purity of acetylene, the acetylene with electronic grade purity needs to be obtained to meet the process requirements.

At present, the purity of acetylene, whether calcium carbide acetylene or natural gas cracking acetylene, cannot meet the requirement of the semiconductor industry on the purity of acetylene, and the acetylene contains impurity components harmful to the amorphous carbon mask preparation, so that the acetylene can not be directly used in the amorphous carbon mask preparation and carburizing process in the semiconductor industry. The raw materials must be purified to remove harmful impurities before use.

The existing acetylene purification technology usually adopts a sodium hypochlorite solution or concentrated sulfuric acid process, only 98-99.5% of acetylene can be obtained finally, and the acetylene cannot enter the semiconductor industry for use; in addition, effective chlorine in the sodium hypochlorite solution purification process is volatile, sodium hypochlorite needs to be continuously supplemented, sodium hypochlorite consumption is large, a large amount of waste liquid needs to be treated, the concentrated sulfuric acid purification process seriously corrodes equipment, waste acid generated after the concentrated sulfuric acid purification process is used is difficult to treat, and the concentrated sulfuric acid is used, so that the requirement on the use operation level is high.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a 4N electronic-grade acetylene purification device. The invention also provides a 4N electronic-grade acetylene purification process.

The invention provides a 4N electronic-grade acetylene purification device, which comprises:

the lower side of the adsorption tower is provided with an input end, and the upper side of the adsorption tower is provided with an output end for removing carbon dioxide in the acetylene raw material;

the low-pressure compressor is connected with the adsorption tower and the absorption tower and is used for compressing the acetylene raw material in the adsorption tower and sending the acetylene raw material into the absorption tower;

an inlet opening for introducing an absorption solvent is arranged above the absorption tower, the top of the absorption tower is used for discharging light component impurities with low solubility and discharging the light component impurities to a tail gas treatment unit, the bottom of the absorption tower is provided with an absorption solvent for absorbing acetylene and heavy component impurities, the absorption solvent enters the desorption tower through an absorption tower kettle pump, the purity of the absorption solvent is 4N level, and wherein the water content is less than 10ppm, the absorption solvent is a combination of any two or more of methanol, ethanol, ethylene glycol or tetrahydrofuran, the absorption solvent is continuously introduced into the absorption tower from the inlet, the introduction flow rate is 1-3kg/h, the temperature of the absorption solvent is-60 to-50 ℃, the pressure is 6 to 8bar, the absorption temperature of the absorption tower is-50-0 ℃, and the absorption pressure is 5-10 bar;

the resolving tower is used for resolving acetylene from the absorption solvent entering the resolving tower, so that 4N electronic-grade acetylene is obtained and is discharged from the top of the resolving tower, and the absorption solvent with heavy component impurities dissolved is discharged from the bottom of the resolving tower; and

the bottom of the desorption tower is connected with the top of the stripping tower through a desorption tower kettle pump and is used for conveying the absorption solvent dissolved with heavy component impurities at the bottom of the desorption tower into the stripping tower, hot nitrogen is connected to the bottom of the stripping tower and is used for separating the heavy component impurities from the absorption solvent in the stripping tower, the separated absorption solvent is discharged from the bottom of the stripping tower through the stripping tower kettle pump and is recycled, and the heavy component impurities are discharged to the tail gas treatment unit.

Optionally, a desorption tower condenser is arranged at the top of the desorption tower and used for discharging the 4N electronic-grade acetylene, and a desorption tower reboiler is arranged at the bottom of the desorption tower and used for providing ascending steam flow into the desorption tower.

Optionally, the desorption tower condenser is connected with a high-pressure compressor for compressing the discharged 4N electronic-grade acetylene and filling the compressed acetylene into a product steel cylinder.

Optionally, a high-pressure drying tower is further included between the high-pressure compressor and the product steel cylinder, and is used for drying the 4N electronic-grade acetylene.

Optionally, the dry adsorbent for drying and dewatering in the high-pressure drying tower is any one or combination of a 3A molecular sieve, a 4A molecular sieve, a 5A molecular sieve, a 13X molecular sieve, alumina or silica gel, and the particle size of the dry adsorbent is 3-5 mm.

Optionally, the adsorbent for adsorbing carbon dioxide in the adsorption tower is any one or combination of sodium hydroxide, potassium hydroxide, lithium hydroxide or calcium hydroxide, and the particle size of the adsorbent is 3-5 mm.

The invention also provides a 4N electronic-grade acetylene purification process, which comprises the steps of firstly removing carbon dioxide in the acetylene raw material, then dissolving the acetylene and heavy component impurities in the acetylene raw material by using an absorption solvent, thereby removing light component impurities with low solubility in the acetylene raw material, finally resolving and separating the acetylene from the absorption solvent, and continuously dissolving the heavy component impurities in the absorption solvent, thereby obtaining the 4N electronic-grade acetylene.

Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages:

1. the method adopts the natural gas cracking acetylene generally accepted by the semiconductor industry as a raw material for purification, adopts an adsorption separation method to separate and purify the acetylene according to different adsorption characteristics of the acetylene and partial impurities, adopts an absorption and analysis method to separate and purify the acetylene according to different solubilities of light component impurity components and heavy component impurity components in the acetylene and the acetylene in a solvent, and combines an absorption and analysis scheme and an adsorption scheme to obtain the 4N electronic-grade acetylene product.

2. The method can purify the natural gas cracking acetylene raw material to 4N-grade purity, meets the requirement of semiconductor industry clients on the acetylene purity, and can recycle the absorption solvent in the process.

3. Because the price of the common acetylene is very low, the price of the 4N electronic grade acetylene is high, and the method has great economic benefit.

Drawings

Fig. 1 is a schematic structural diagram of a 4N electronic-grade acetylene purification device according to an embodiment of the present application.

Reference numerals:

an adsorption tower-1; a low pressure compressor-2; an absorption tower-3; resolving tower-4; a resolving tower condenser-5; a reboiler-6 of the desorption tower; a stripper-7; a pump-8 of the resolution tower kettle; a stripper kettle pump-9; high pressure drying tower-10; a high-pressure compressor-11; product steel cylinder-12; absorption column kettle pump-13.

Detailed Description

The invention is further described with reference to the accompanying drawings and examples:

fig. 1 is a schematic structural diagram of a 4N electronic-grade acetylene purification device according to an embodiment of the present application. Referring to fig. 1, the purification apparatus includes: adsorption tower 1, low pressure compressor 2, absorption tower 3 and desorption tower 4.

The lower side of the adsorption tower 1 is provided with an input end, and the upper side is provided with an output end for removing carbon dioxide in acetylene raw materials. Under normal temperature and pressure, acetylene raw materials enter an adsorption tower 1 from an input end at the flow rate of 6-15kg/h, an adsorbent is filled in the adsorption tower 1 and used for adsorbing carbon dioxide in the acetylene raw materials, the adsorbent can be any one or combination of sodium hydroxide, potassium hydroxide, lithium hydroxide or calcium hydroxide, and the particle size of the adsorbent is 3-5 mm.

The low-pressure compressor 2 is connected with the adsorption tower 1 and the absorption tower 3 and is used for compressing the acetylene raw material without carbon dioxide in the adsorption tower 1 and sending the acetylene raw material into the absorption tower 3; the acetylene raw material is pressurized to 5-10bar by the low-pressure compressor 2 and then sent into the absorption tower 3.

An inlet through which the absorption solvent can be introduced is arranged above the absorption tower 3, and the absorption solvent is continuously introduced into the absorption tower 3 from the inlet, wherein the introduction flow rate is 1-3 kg/h. The absorption solvent can be selected from methanol, ethanol, ethylene glycol or tetrahydrofuran. The output temperature range of the absorption solvent is-60 to-50 ℃, and the output pressure is 6 to 8 bar. The operation temperature of the absorption tower 3 is-50-0 ℃, the operation pressure of the absorption tower is 5-10bar, the top of the absorption tower 3 is used for discharging light component impurities with low solubility, the discharge flow is 2-5kg/h and is discharged to a tail gas treatment unit, the bottom of the absorption tower 3 is absorption solvent which absorbs acetylene and heavy component impurities and enters the desorption tower 4 through an absorption tower kettle pump 13, and the flow is 184-190 kg/h.

The absorption solvent that this application adopted, it is 4N level purity and adopt two kinds at least compound mode, combine specific absorption temperature and pressure, under the prerequisite of guaranteeing not to introduce new impurity, both can increase the solubility of hydrocarbon impurity, also can strengthen acetylene and hydrocarbon impurity's selectivity for absorption solvent can selectively absorb less hydrocarbon impurity, and selects to absorb more acetylene, thereby reaches the requirement of purification 4N level acetylene.

The liquid outlet at the bottom of the absorption tower 3 is connected with the input end at the upper side of the desorption tower 4, the acetylene raw material is removed of light component impurities with low solubility by the absorption tower 3 and then enters the desorption tower 4 along with the absorption solvent to desorb the acetylene dissolved in the solvent, the desorption temperature of the desorption tower 4 is 10-40 ℃, and the desorption pressure is 1.1-1.5 bar. The top of the desorption tower 4 is provided with a desorption tower condenser 5 for discharging the 4N electronic-grade acetylene with the flow rate of 3-8kg/h, and the bottom of the desorption tower 4 is provided with a desorption tower reboiler 6 for providing ascending steam flow into the desorption tower 4. The absorption solvent with the dissolved heavy component impurities is discharged from the bottom of the desorption tower 4 and enters the stripping tower 7 by using a desorption tower kettle pump 8, and the flow rate is 181-182 kg/h.

4N electronic-grade acetylene obtained from the top of the desorption tower 4 is pressurized to 1.8-2.2MPa by a high-pressure compressor 11, enters a high-pressure drying tower 10 for drying and dehydration, and then enters a product steel cylinder 12 for filling to obtain a 4N electronic-grade acetylene product. The drying adsorbent used for drying and dewatering in the high-pressure drying tower 10 is any one or combination of a plurality of 3A molecular sieve, a 4A molecular sieve, a 5A molecular sieve, a 13X molecular sieve, alumina or silica gel, and the particle size of the drying adsorbent is 3-5 mm. The adsorption temperature in the high-pressure drying tower 10 is 0-30 ℃, and the adsorption pressure is 1.8-2.2 MPa.

The bottom of the desorption tower 4 is connected with the top of the stripping tower 7 through a desorption tower kettle pump 8 and is used for sending the absorption solvent dissolved with heavy component impurities at the bottom of the desorption tower 4 into the stripping tower 7, the bottom of the stripping tower 7 is connected with hot nitrogen and is used for separating the heavy component impurities from the absorption solvent in the stripping tower 7, the separated absorption solvent is pressurized to 6-8bar from the bottom of the stripping tower 7 through a stripping tower kettle pump 9 and then is recycled in the absorption tower 3, and the flow is 177 and 179 kg/h. And discharging the heavy component impurities to the tail gas treatment unit, wherein the discharge flow rate is 2-5 kg/h. The operation temperature of the stripping tower 7 is 50-140 ℃, the pressure is 1.05-1.5bar, the temperature of hot nitrogen at the bottom of the stripping tower is 50-140 ℃, the pressure is 1.1-1.5bar, and the flow rate is 100 plus 300L/min.

The application utilizes the stripping tower to separate the absorption solvent from the heavy component impurities thoroughly, so that the separated absorption solvent does not contain the heavy component impurities, the absorption tower can be used for continuous use, and a necessary purification basis is provided for the purification of high-purity acetylene. Compared with a reboiling mode in the prior art, the absorption solvent obtained by separation is purer, and the device can not be blocked due to polymerization reaction with impurities on the premise of repeated boiling.

The embodiment of the invention also provides a 4N electronic-grade acetylene purification process, which comprises the steps of firstly removing carbon dioxide in the acetylene raw material, then dissolving acetylene and heavy component impurities in the acetylene raw material by using an absorption solvent, thereby removing light component impurities with low solubility in the acetylene raw material, finally resolving and separating acetylene from the absorption solvent, and continuously dissolving the heavy component impurities in the absorption solvent, thereby obtaining the 4N electronic-grade acetylene.

Example 1

Under normal temperature and normal pressure, acetylene raw materials enter an adsorption tower 1 from the input end of the adsorption tower 1 at the flow rate of 10kg/h, and sodium hydroxide with the particle size of 4mm is filled in the adsorption tower 1 to be used as an adsorbent for adsorbing carbon dioxide in the acetylene raw materials; the acetylene feed is pressurized to 10bar by the low pressure compressor 2 and then fed into the absorber 3.

The absorption solvent is a mixture of methanol and ethanol, and is continuously introduced into the absorption tower 3 from an inlet above the absorption tower 3, wherein the introduction flow rate is 2 kg/h. The temperature of the absorption solvent was-60 ℃ and the pressure was 7 bar. The absorption temperature of the absorption tower 3 is-50 ℃, the absorption pressure is 5bar, the top of the absorption tower 3 is used for discharging light component impurities with low solubility, the discharge flow is 3kg/h and discharging the light component impurities to a tail gas treatment unit, the bottom of the absorption tower 3 is absorption solvent which absorbs acetylene and heavy component impurities and enters the desorption tower 4 through an absorption tower kettle pump 13, and the flow is 185 kg/h.

The resolving tower 4 resolves the acetylene dissolved in the solvent, the resolving temperature of the resolving tower 4 is 20 ℃, and the resolving pressure is 1.2 bar. The top of the desorption tower 4 is provided with a desorption tower condenser 5 for discharging the 4N electronic-grade acetylene with the flow rate of 5kg/h, and the bottom of the desorption tower 4 is provided with a desorption tower reboiler 6 for providing ascending steam flow into the desorption tower 4. The absorption solvent with the dissolved heavy component impurities is discharged from the bottom of the desorption tower 4, and enters a stripping tower 7 by using a desorption tower kettle pump 8, and the flow rate is 181 kg/h.

4N electronic-grade acetylene obtained from the top of the desorption tower 4 is pressurized to 2.0MPa by a high-pressure compressor 11 and then enters a high-pressure drying tower 10 for drying and dehydration, a drying adsorbent for drying and dehydration in the high-pressure drying tower 10 is a 3A molecular sieve, the particle size is 4mm, the adsorption temperature in the high-pressure drying tower 10 is 20 ℃, and the adsorption pressure is 2.0 MPa. And after dehydration, the product enters a product steel cylinder 12 to be filled to obtain a 4N electronic-grade acetylene product.

The bottom of the desorption tower 4 is connected with the top of the stripping tower 7 through a desorption tower kettle pump 8 and is used for conveying the absorption solvent dissolved with heavy component impurities at the bottom of the desorption tower 4 into the stripping tower 7, hot nitrogen is connected to the bottom of the stripping tower 7 and is used for separating the heavy component impurities from the absorption solvent in the stripping tower 7, and the separated absorption solvent is pressurized to 7bar from the bottom of the stripping tower 7 through a stripping tower kettle pump 9 and then is recycled to the absorption tower 3, and the flow rate is 178 kg/h. The heavy component impurities are discharged to the tail gas treatment unit, and the discharge flow rate is 5 kg/h. The operation temperature of the stripping tower 7 is 120 ℃, the pressure is 1.2bar, the temperature of hot nitrogen at the bottom of the tower is 100 ℃, the pressure is 1.2bar, and the flow rate is 200L/min.

Example 2

Under normal temperature and normal pressure, acetylene raw materials enter an adsorption tower 1 from the input end of the adsorption tower 1 at the flow rate of 15kg/h, and potassium hydroxide with the particle size of 5mm is filled in the adsorption tower 1 and is used for adsorbing carbon dioxide in the acetylene raw materials; the acetylene feed is pressurized to 8bar by the low pressure compressor 2 and then fed into the absorber 3.

The absorption solvent is a mixture of methanol and glycol, and is continuously introduced into the absorption tower 3 from an inlet above the absorption tower 3, wherein the introduction flow rate is 3 kg/h. The temperature of the absorption solvent was-50 ℃ and the pressure was 8 bar. The absorption temperature of the absorption tower 3 is-40 ℃, the absorption pressure is 10bar, the top of the absorption tower 3 is used for discharging light component impurities with low solubility, the discharge flow is 5kg/h, and the light component impurities are discharged to a tail gas treatment unit, the bottom of the absorption tower 3 is absorption solvent which absorbs acetylene and heavy component impurities and enters the desorption tower 4 through an absorption tower kettle pump 13, and the flow is 190 kg/h.

The resolving tower 4 resolves the acetylene dissolved in the solvent, the resolving temperature of the resolving tower 4 is 40 ℃, and the resolving pressure is 1.5 bar. The top of the desorption tower 4 is provided with a desorption tower condenser 5 for discharging the 4N electronic-grade acetylene with the flow rate of 8kg/h, and the bottom of the desorption tower 4 is provided with a desorption tower reboiler 6 for providing ascending steam flow into the desorption tower 4. The absorption solvent with the dissolved heavy component impurities is discharged from the bottom of the desorption tower 4, and enters a stripping tower 7 by using a desorption tower kettle pump 8, and the flow rate is 181 kg/h.

4N electronic-grade acetylene obtained from the top of the desorption tower 4 is pressurized to 1.8MPa by a high-pressure compressor 11 and then enters a high-pressure drying tower 10 for drying and dehydration, a drying adsorbent for drying and dehydration in the high-pressure drying tower 10 is a 13X molecular sieve, the particle size is 5mm, the adsorption temperature in the high-pressure drying tower 10 is 30 ℃, and the adsorption pressure is 1.8 MPa. And after dehydration, the product enters a product steel cylinder 12 to be filled to obtain a 4N electronic-grade acetylene product.

The bottom of the desorption tower 4 is connected with the top of the stripping tower 7 through a desorption tower kettle pump 8 and is used for conveying the absorption solvent dissolved with heavy component impurities at the bottom of the desorption tower 4 into the stripping tower 7, hot nitrogen is connected to the bottom of the stripping tower 7 and is used for separating the heavy component impurities from the absorption solvent in the stripping tower 7, and the separated absorption solvent is pressurized to 8bar from the bottom of the stripping tower 7 through a stripping tower kettle pump 9 and then is recycled to the absorption tower 3, and the flow rate is 178 kg/h. The heavy component impurities are discharged to the tail gas treatment unit, and the discharge flow rate is 5 kg/h. The operation temperature of the stripping tower 7 is 140 ℃, the pressure is 1.5bar, the temperature of hot nitrogen at the bottom of the tower is 140 ℃, the pressure is 1.5bar, and the flow rate is 300L/min.

Example 3

Under normal temperature and normal pressure, acetylene raw materials enter an adsorption tower 1 from the input end of the adsorption tower 1 at the flow rate of 6kg/h, and calcium hydroxide with the particle size of 3mm is filled in the adsorption tower 1 and is used for adsorbing carbon dioxide in the acetylene raw materials; the acetylene feed is pressurized to 5bar by the low pressure compressor 2 and then fed into the absorber 3.

The absorption solvent is a mixture of methanol, ethanol and tetrahydrofuran, and is continuously introduced into the absorption tower 3 from an inlet above the absorption tower 3, and the introduction flow rate is 1 kg/h. The temperature of the absorption solvent was-55 ℃ and the pressure 6 bar. The absorption temperature of the absorption tower 3 is-10 ℃, the absorption pressure is 5bar, the top of the absorption tower 3 is used for discharging light component impurities with low solubility, the discharge flow is 2kg/h and discharging the light component impurities to a tail gas treatment unit, the bottom of the absorption tower 3 is absorption solvent which absorbs acetylene and heavy component impurities and enters the desorption tower 4 through an absorption tower kettle pump 13, and the flow is 184 kg/h.

The resolving tower 4 resolves the acetylene dissolved in the solvent, the resolving temperature of the resolving tower 4 is 10 ℃, and the resolving pressure is 1.1-bar. The top of the desorption tower 4 is provided with a desorption tower condenser 5 for discharging the 4N electronic-grade acetylene with the flow rate of 3kg/h, and the bottom of the desorption tower 4 is provided with a desorption tower reboiler 6 for providing ascending steam flow into the desorption tower 4. The absorption solvent with the heavy component impurities dissolved therein is discharged from the bottom of the desorption tower 4, and enters the stripping tower 7 by using a desorption tower kettle pump 8, wherein the flow rate is 182 kg/h.

4N electronic-grade acetylene obtained from the top of the desorption tower 4 is pressurized to 2.2MPa by a high-pressure compressor 11 and then enters a high-pressure drying tower 10 for drying and dehydration, a drying adsorbent for drying and dehydration in the high-pressure drying tower 10 is silica gel, the particle size is 3mm, the adsorption temperature in the high-pressure drying tower 10 is 10 ℃, and the adsorption pressure is 2.2 MPa. And after dehydration, the product enters a product steel cylinder 12 to be filled to obtain a 4N electronic-grade acetylene product.

The bottom of the desorption tower 4 is connected with the top of the stripping tower 7 through a desorption tower kettle pump 8 and is used for conveying the absorption solvent dissolved with heavy component impurities at the bottom of the desorption tower 4 into the stripping tower 7, hot nitrogen is connected to the bottom of the stripping tower 7 and is used for separating the heavy component impurities from the absorption solvent in the stripping tower 7, the separated absorption solvent is pressurized to 6bar from the bottom of the stripping tower 7 through a stripping tower kettle pump 9 and then is recycled to the absorption tower 3, and the flow is 179 kg/h. The heavy component impurities are discharged to the tail gas treatment unit, and the discharge flow rate is 2 kg/h. The operating temperature of the stripping tower 7 is 50 ℃, the pressure is 1.05bar, the temperature of hot nitrogen at the bottom of the tower is 50 ℃, the pressure is 1.1bar, and the flow is 100L/min.

Comparative example 1

Comparative example 1 differs from example 1 in that the absorption solvent is methanol; the rest of the steps and process parameters were identical to those of example 1.

Comparative example 2

Comparative example 2 differs from example 1 in that the absorption solvent is ethanol; the rest of the steps and process parameters were identical to those of example 1.

Comparative example 3

The difference between the comparative example 3 and the example 1 is that the absorption temperature of the absorption tower 3 is 5 ℃, the absorption pressure is 0.5MPa, the temperature of the absorption solvent is 5 ℃, and the absorption pressure is 0.5 MPa; the rest of the steps and process parameters were identical to those of example 1.

Table 1 shows a comparison of the compositions (volume fractions) of the acetylene feed and the acetylene product before and after the practice of example 1 and comparative examples 1 to 3 of the present application. As can be seen from Table 1, the purity of acetylene is significantly improved after treatment by the purification device of the present application.

TABLE 1 Natural gas cracking acetylene feed and product composition (volume fraction)

As can be seen from table 1, the selection of the absorption solvent and the temperature and pressure of the absorption solvent and the absorption column play a critical role in acetylene purification, which is a prerequisite for obtaining 4N electronic grade acetylene products.

The method adopts the natural gas cracking acetylene generally accepted by the semiconductor industry as a raw material for purification, adopts an adsorption separation method to separate and purify the acetylene according to different adsorption characteristics of the acetylene and partial impurities, adopts an absorption and analysis method to separate and purify the acetylene according to different solubilities of light component impurity components and heavy component impurity components in the acetylene and the acetylene in a solvent, and combines an absorption and analysis scheme and an adsorption scheme to obtain the 4N electronic-grade acetylene product.

The method can purify the natural gas cracking acetylene raw material to 4N-grade purity, meets the requirement of semiconductor industry clients on the acetylene purity, and can recycle the absorption solvent in the process.

Because the price of the common acetylene is very low, the price of the 4N electronic grade acetylene is high, and the method has great economic benefit.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.