JP2010207727A - Apparatus and method for purifying gas - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact-sized apparatus for purifying a gas having an improved capability of concentrating CO<SB>2</SB>, and a method of purifying a gas. <P>SOLUTION: The apparatus 10 for purifying a gas includes a first static mixer 13-1 that mixes a beer-fermentation gas 11A comprising CO<SB>2</SB>and air with absorption water 12 to separate the CO<SB>2</SB>from the beer-fermentation gas 11A, a first absorption column 14-1 that causes a beer-fermentation gas 11B to further contact the absorption water 12 to separate the air and CO<SB>2</SB>, a first stripping column 15-1 that releases the CO<SB>2</SB>in the absorption water 12, a second static mixer 13-2 that further mixes the CO<SB>2</SB>gas 16A released from the first stripping column 15-1 with the absorption water 12 to separate the CO<SB>2</SB>from the CO<SB>2</SB>gas 16A, a second absorption column 14-2 that separates the CO<SB>2</SB>gas 16B into air and CO<SB>2</SB>, and a second stripping column 15-2 that releases the CO<SB>2</SB>in the absorption water 12. By releasing the CO<SB>2</SB>absorbed again in the absorption water 12, a CO<SB>2</SB>gas 16C wherein the CO<SB>2</SB>is further concentrated to a higher concentration can be obtained. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a gas purification apparatus and a gas purification method for purifying carbon dioxide (CO ₂ ) concentrated to a high purity from beer fermentation gas generated in a beer production process, for example.

Biologically, organic waste generated in sewage treatment plants, food factories, beer factories, livestock farms, etc., such as sludge, garbage, human waste, etc., is anaerobically treated in a tank and fermented. When the treatment is performed, methane fermentation gas (digestion gas) composed of methane (CH ₄ ), CO ₂ , hydrogen sulfide (H ₂ S), etc. is generated. The main components of this digestion gas are CO ₂ and CH ₄ , which contains CH _4, for example, about 60%, CO _2, for example, about 30-40%, and also contains H ₂ S and the like. In recent years, it has been studied to effectively use a gas produced by biofermentation such as digestion gas as an energy source.

In addition, beer fermentation gas produced by biofermentation from a fermentation tank in the beer production process contains CO ₂ and air as main components. As a method for concentrating removed by separating the CO ₂ from the beer fermentation gas, for example, to absorb CO ₂ absorption liquid amine, the CO ₂ dissolved in the absorption liquid is collected and chemical absorption method of purifying It has been proposed to employ the gas purification apparatus used (see, for example, Patent Documents 1 and 2).

As a method for separating CO ₂ , in addition to a chemical absorption method using an amine-based absorption liquid, a physical absorption method in which CO ₂ is absorbed in water or the like under high pressure, an adsorption using an adsorbent such as zeolite. There are laws.

Japanese Patent Laid-Open No. 10-15334 JP 2006-299105 A

Here, for example, the gas discharged from the fermentation tank beer production process, in the second half fermentation, although the CO ₂ concentration is purified of CO ₂ is recovered due to the high, the fermentation early, because the CO ₂ concentration is low, CO ₂ is discharged into the atmosphere without being recovered. Purification of CO ₂ The CO ₂ concentration using the existing CO ₂ purification apparatus by concentrating the CO ₂ also low gas, it is possible to achieve the reuse.

However, in order to purify and reuse the fermentation gas discharged from the fermentation tank, it is necessary to separate and concentrate CO ₂ with a very high purity, for example, a concentrated CO ₂ concentration of 99.5% or more. There is a problem that.

In addition, in the physical absorption method, CO ₂ contained in the fermentation gas is removed by water absorption in the absorption tower, so it is necessary to increase the size of the apparatus such as increasing the height of the absorption tower, and chemical absorption. The law is not suitable for small and medium-sized gas processing, and there is a problem that the economy is not good.

Furthermore, the adsorption method has a problem that it is difficult to concentrate the CO ₂ concentration to a high purity of, for example, 99.5% or more.

The present invention was made in view of the above problems, it improves the concentration performance of the CO _2, and to provide a gas purifier and a gas purification method downsized.

The first aspect of the present invention to solve the above problems, the water solubility of CO ₂ is less than the gas component, the CO ₂ containing gas containing the CO ₂ is mixed with the absorption water, the absorption water the dissolved CO _2, contact a first mixing means for separating the CO ₂ from the CO ₂ containing gas, and further absorb water CO ₂ containing gas after mixing with the absorbent water by the first mixing means is not the CO ₂ of the CO ₂ containing gas is dissolved in the absorption water, either one or both of the first absorption tower solubility in the water to separate and the CO ₂ CO ₂ smaller gas component When a first diffusion column to dissipate CO ₂ absorption water that has absorbed CO ₂ in the CO ₂ containing gas in the first absorption tower, the CO ₂ gas diffused from the first stripping column further mixed to absorb water, dissolved CO ₂ in the absorption water, from the CO ₂ gas Said second mixing means, the CO ₂ of the second mixture by further contact with the absorption water CO ₂ containing gas after mixing with the absorbent water by means the CO ₂ containing gas to separate the CO ₂ One or both of a second absorption tower which dissolves in water and separates the gas component having a solubility in water smaller than CO ₂ and CO ₂ , the second mixing means or the second a second diffusion column to dissipate CO ₂ of the absorbent water that has absorbed CO ₂ in the absorption tower, have, to the CO ₂ in the CO ₂ gas is dissipated from the second stripping column and high purity It is in the gas purification apparatus characterized by this.

  According to a second invention, in the first invention, a first concentrator comprising the first mixing means, the first absorption tower, and the first stripping tower, and the second mixing means. And a second concentrating device composed of the second absorption tower and the second stripping tower, or both of them.

  A third invention is the gas purification apparatus according to the first or second invention, wherein the first mixing means and the second mixing means are static mixers or line mixers.

  According to a fourth invention, in any one of the first to third inventions, the first absorption tower is a packed tower provided with a packed bed or a plate tower provided with a shelf board. It is in the gas purifier.

  According to a fifth invention, in any one of the first to fourth inventions, the second absorption tower is any one of a spray tower, a scrubber, a wet wall tower, a bubble tower, or a bubble stirring tower. It is in the gas purification device that features it.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the absorption water in which CO ₂ is diffused in the first diffusion tower and the second diffusion tower is used as the first absorption tower and the second absorption tower. The gas purifier includes a first absorption water circulation line and a second absorption water circulation line that are circulated through the two absorption towers.

  According to a seventh invention, in any one of the first to sixth inventions, in the second mixing means or the second absorption tower, non-absorbed gas that has not been absorbed by absorbed water is added to the first mixing means. Alternatively, the gas purifier includes a non-absorbing gas return line that returns to the upstream side of the first absorption tower.

According to an eighth invention, in any one of the first to seventh inventions, the gas component having a solubility in water smaller than CO ₂ is at least one of air, CH ₄ , N ₂ , O ₂ , H ₂ , and He. The gas purifier is characterized by comprising a gas.

A ninth invention is the gas purification apparatus according to any one of the first to eighth inventions, wherein the CO ₂ -containing gas is a beer fermentation gas produced by biofermentation.

According to a tenth aspect of the present invention, in any one of the first to ninth aspects, the CO ₂ -containing gas is introduced into the first absorption tower in either one or both of the first absorption tower and the second absorption tower. Alternatively, either one of or both of the second absorption towers are introduced from the upper part of both towers, and CO ₂ -absorbed water is absorbed in either or both of the first absorption tower or the second absorption tower. The gas purification apparatus is characterized by being extracted from the bottom side.

An eleventh invention, the water solubility of CO ₂ is less than the gas component, the CO ₂ containing gas containing the CO ₂ mixed with absorbing water, dissolved CO ₂ in the absorption water, the CO ₂ content a first mixing step of separating CO ₂ from gas, dissolved CO ₂ in the absorption water mixed with by further contact with the absorption water containing CO ₂ gas after the CO ₂ containing gas to the absorbing water , solubility in the water is absorbed and either or both of the steps, the CO ₂ of the CO ₂ containing gas of the first CO ₂ absorption step to separate and the CO ₂ CO ₂ smaller gas component a first CO ₂ gas stripping step to dissipate absorbed water CO _2, the first CO ₂ mixed with further absorb water dissipated CO ₂ gas by the gas stripping step, dissolved CO ₂ in the absorption water is a second mixing step of separating CO ₂ from the CO ₂ gas, wherein Is further contacted with absorbing water CO ₂ containing gas after mixing with Osamumizu by dissolving CO ₂ in the CO ₂ containing gas into the absorbing water, solubility in the water CO ₂ is less than the gas component and the CO _The absorbed water in which CO ₂ is absorbed by the one or both of the second CO ₂ absorption step for separating ₂ and the second CO ₂ gas mixing step or the second CO ₂ absorption step. and a second CO ₂ gas stripping step to dissipate the CO _2, the gas purification, characterized in that the CO ₂ in the CO ₂ gas is dissipated from the second CO ₂ gas stripping step with high purity Is in the way.

In a twelfth aspect based on the eleventh aspect, the first concentration step comprising the first mixing step, the first CO ₂ absorption step, and the first CO ₂ gas diffusion step, and having either one or both steps of the second concentration step composed of a second mixing step and the second CO ₂ absorption step and the second CO ₂ gas stripping step In the gas purification method.

In a thirteenth aspect based on the eleventh or twelfth aspect, the first mixing step and the second mixing step mix the CO ₂ -containing gas with the absorbed water using a static mixer or a line mixer. The gas purification method is characterized by the following.

A fourteenth invention is characterized in that, in any one of the eleventh to thirteenth inventions, the first CO ₂ absorption step uses a packed tower provided with a packed bed or a plate tower provided with a shelf board. It is in the gas purification method.

In a fifteenth aspect based on any one of the eleventh to fourteenth aspects, the second CO ₂ absorption step uses any one of a spray tower, a scrubber, a wet wall tower, a bubble tower, or a bubble stirring tower. In the gas purification method characterized by this.

According to a sixteenth aspect of the present invention, in any one of the eleventh to fifteenth aspects, the absorbed water in which CO ₂ is diffused in the first CO ₂ gas diffusion step and the second CO ₂ gas diffusion step is used in the first aspect. In the gas purification method, the absorbed water used in the CO ₂ absorption step and the second CO ₂ absorption step is circulated.

  According to a seventeenth aspect of the present invention, in any one of the eleventh to sixteenth aspects of the present invention, in the second mixing means or the second absorption tower, non-absorbed gas that has not been absorbed by absorbed water is removed from the first mixing means. Alternatively, the gas purification method is characterized by returning to the upstream side of the first absorption tower and processing again.

According to an eighteenth aspect of the present invention, in any one of the eleventh to seventeenth aspects, the gas component whose solubility in water is smaller than CO ₂ is at least one of air, CH ₄ , N ₂ , O ₂ , H ₂ , and He. The gas purification method is characterized by comprising a gas.

A nineteenth invention is the gas purification method according to any one of the eleventh to eighteenth inventions, wherein the CO ₂ -containing gas is a beer fermentation gas produced by biofermentation.

In a twentieth aspect of the present invention, in any one of the eleventh to nineteenth aspects, the CO ₂ -containing gas is removed from the absorption tower in one or both of the first CO ₂ absorption step and the second CO ₂ absorption step. The gas purification method is characterized in that it is introduced from the top of the tower and the absorbed water having absorbed CO ₂ is extracted from the tower bottom side of the absorption tower.

According to the gas purification system according to the present embodiment, a first mixing means and the first absorption tower, in a first stripping column, and the solubility in water CO ₂ smaller gas component, and a CO ₂ of CO ₂ CO ₂ containing gas containing absorbed into absorbing water, by dissipating the CO ₂ absorbed into the absorbing water, it is possible to increase the CO ₂ concentration of CO ₂ in the gas recovered. Then, the second mixing means, and either or both of the second absorption tower, in the second stripping column, the recovered CO ₂ gas, again, to absorb the absorbed water, the absorbed water Can absorb CO ₂ at a higher concentration. By releasing again the CO ₂ absorbed in the absorbed water, a high-purity CO ₂ gas concentrated to a higher concentration can be obtained. Therefore, by using the gas purifier according to the present invention, the CO ₂ and CO ₂ containing gas and two-stage concentrating, it is possible to recover high purity CO ₂ gas.

Moreover, the gas purification apparatus according to the present embodiment is a hybrid absorption system in which at least a first mixing unit is provided and the first mixing unit and the first absorption tower are combined. Therefore, a part of CO ₂ in the CO ₂ -containing gas is dissolved in the absorption water in advance in the first absorption tower, and the first absorption tower is mixed with the absorption water to supply the CO ₂ -containing gas. Since the absorption load on the absorption water of CO ₂ in the CO ₂ -containing gas in the CO ₂ -containing gas can be reduced in the absorption tower, the tower height of the first absorption tower can be made lower than before, and the size of the apparatus can be reduced. Can be achieved.

FIG. 1 is a schematic diagram showing the configuration of a gas purification apparatus according to an embodiment of the present invention. FIG. 2 is a schematic view showing another configuration of the gas purification apparatus according to the embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those in a so-called equivalent range.
As shown in FIG. 1, the gas purification apparatus 10 according to the embodiment of the present invention mixes beer fermentation gas 11A containing CO ₂ and air with absorbed water 12, dissolves CO ₂ in the absorbed water 12, A first static mixer (first mixing means) 13-1 that separates CO ₂ from the beer fermentation gas 11 A, and the beer fermentation gas 11 B after being mixed with the absorbed water 12 by the first static mixer 13-1 are further added. in contact with the absorbing water 12 dissolved CO ₂ in the beer fermentation gases 11B to absorb water 12, the first absorption tower 14-1 for separating the air and CO _2, in the first absorption tower 14 - a first diffusion column 15-1 for dissipating CO ₂ in the absorption water 12 that has absorbed CO _2, further mixed to absorb water 12 CO ₂ gas 16A that is dissipated from the first stripping column 15-1, during the absorption water 12 to dissolve the CO _2, CO ₂ gas 1 A second static mixer (second mixing means) 13-2 for separating the CO ₂ from A, with the CO ₂ gas 16 that is dissipated into contact with the absorbed water 12 from the first stripping column 15-1 CO ₂ CO ₂ in the gas 16A is dissolved in the absorption water 12, and the second absorption tower 14-2 that separates the CO _{2 from} the air that has not been absorbed by the absorption water 12, and the second absorption tower 14-2 is used for CO. _{And a second} diffusion tower 15-2 that diffuses CO ₂ in the absorption water 12 that has absorbed ₂ .

  That is, the gas purification apparatus 10 according to the embodiment of the present invention includes the first concentrator A and the second concentrator B. The first concentrator A includes a first static mixer (first mixing means) 13-1, a first absorption tower 14-1, and a first diffusion tower 15-1. The second concentrator B is composed of a second static mixer (second mixing means) 13-2, a second absorption tower 14-2, and a second stripping tower 15-2.

In the present embodiment, the beer fermentation gas 11A containing CO ₂ and air produced by biofermentation in the beer production process as the CO ₂ containing gas will be described.
In addition, the gas purification device is provided in the retrofit to recover the beer fermentation gas 11A produced by biofermentation from a gas source such as a fermentation tank in an existing beer production process, and simultaneously with a new exhaust gas source. May be attached.

Gas purifier 10 according to this embodiment, the CO ₂ is separated from the produced beer fermentation gas 11A, the first concentration step I to produce a CO ₂ gas 16A, further the CO ₂ concentration of CO ₂ gas 16A It consists of a second concentration step II that concentrates to a high concentration and produces CO ₂ gas 16C.
In addition, the first concentration step I includes a first mixing step I-2A and a first mixing step I-2A configured by a first gas compression step I-1 for compressing the beer fermentation gas 11A and a first static mixer 13-1. first and absorption step I-2 consisting of a first CO ₂ gas absorption step I-2B composed of one of the absorption tower 14-1, first CO ₂ of a first stripping column 15-1 It is comprised with the gas diffusion process I-3.
The second concentration step II includes a second gas compression step II-1 for compressing the CO ₂ gas 16A recovered from the first CO ₂ gas emission step I-3, and a second static mixer 13-. A second absorption step II-2 consisting of a second mixing step II-2A constituted by 2 and a _second CO ₂ gas absorption step II-2B constituted by the second absorption tower 14-2; composed of the second CO ₂ gas stripping step II-3 of a second stripping column 15-2.

(First concentration step I)
As described above, the first concentration step I includes the first gas compression step I-1, the first absorption step I-2, and the first CO ₂ gas diffusion step I-3.

(First gas compression step I-1)
Beer Fermentation gas 11A is generated, for example by bio-fermentation in the beer production process, air containing CO ₂ or the like as a main component. The beer fermentation gas 11A containing air and CO ₂ discharged in the beer production process is sent to a gas filter (demister built-in type) 22, and after dust removal and mist removal, it is introduced into the gas compressor 23-1, The pressure is increased by the gas compressor 23-1. The pressurized beer fermentation gas 11A is sent to the gas cooler 24-1, cooled by cooling water, and then fed to the first static mixer 13-1.

  A reciprocating type or the like is used as the gas compressor 23-1. The pressure of the beer fermentation gas 11A is detected by the gas pressure detector 25-1, and the opening and closing of the on-off valve V1 provided in the reflux passage 26-1 is adjusted to thereby adjust the beer fermentation gas 11A at the outlet of the gas compressor 23-1. A part is refluxed to the inlet of the gas compressor 23-1. By recirculating a part of the beer fermentation gas 11A, the beer fermentation gas 11A can be controlled in accordance with the flow rate fluctuation. The on-off valve V2 is a valve that shuts off the supply of the beer fermentation gas 11A to the first static mixer 13-1 when the gas purification apparatus 10 is stopped.

(First absorption step I-2)
As described above, the first absorption process I-2 includes the first mixing process I-2A configured by the first static mixer 13-1 and the CO ₂ gas absorption process I- configured by the absorption tower 14. 2B.
In the first static mixer 13-1, CO ₂ in the beer fermentation gas 11A is selectively dissolved in the absorption water 12 and separated. The higher the operating pressure in the first static mixer 13-1, the higher the CO ₂ solubility and the higher the CO ₂ absorption efficiency. However, when the operating pressure increases, the power consumption of the gas compressor 23-1 increases. Since it rises and the operating cost increases, for example, the gas compressor 23-1 is pressurized to a pressure of 0.6 MPaG or less. Therefore, since the beer fermentation gas 11A pressurized by the gas compressor 23-1 rises in temperature, the beer fermentation gas 11A is cooled to room temperature by the gas cooler 24-1, and then fed to the first static mixer 13-1. .

As will be described later, CO ₂ in the beer fermentation gas 11A is absorbed into the absorbed water 12 in the first static mixer 13-1 and the first absorption tower 14-1. The CO ₂ absorption step for absorbing the CO ₂ in the absorbing water 12 in the first static mixer 13-1 and the first absorption column 14-1, a high pressure conditions, the absorption of CO ₂ in the absorbing water 12 Like to do.

Here, Table 1 shows the solubility of the gas component. Table 1 shows the solubility of each gas when the pressure is 1 atm and the concentration is 100%. The solubility in water varies depending on the gas component, temperature, and partial pressure of each gas, but as shown in Table 1, the solubility increases as the temperature decreases. The solubility is proportional to the gas partial pressure, and increases as the gas partial pressure increases. In Table 1, the solubility of CO ₂ , CH ₄ , N ₂ and O ₂ is shown as an example, but CO ₂ is more water than other gas components such as CH ₄ , N ₂ , O ₂ , H ₂ and He. Solubility in

Therefore, when the beer fermentation gas 11A is brought into gas-liquid contact with the absorption water 12, the dissolved amount of CO ₂ is larger than the dissolved amount of other gas components such as CH ₄ , N ₂ , O ₂ , H ₂ and He. ₂ can be separated from other gas components such as CH ₄ , N ₂ , O ₂ , H ₂ , and He. Therefore, either the static mixer or the absorption tower is obtained by adopting a hybrid system in which the first absorption process is a combination of the simple absorption equipment such as the first static mixer 13-1 and the first absorption tower 14-1. CO ₂ in the beer fermentation gas 11A can be efficiently absorbed in the absorbed water 12 as compared with the case where only the slag is used.

Moreover, as will be described later, the second absorption step II-2 including the second static mixer 13-2 and the second absorption tower 14-2 includes the first static mixer 13-1 and the first absorption tower. The absorption efficiency of CO _{2 into} the absorption water 12 is lower than that of the first absorption step I-2 made of 14-1. When CO ₂ is absorbed into the absorption water 12, the pH of the absorption water 12 decreases, and conversely, it becomes difficult to absorb CO ₂ into the absorption water 12. Also, if other gas components be able to absorb the CO ₂ in the absorbing water 12 is absorbed at the same time, the gas to be dissipated from the absorbing water 12, other gas components other than CO ₂ since that is to be contained many, the purity of the CO ₂ in the CO ₂ gas 16C recovered from the second stripping column 15-2 is lowered. That is, since the decrease in pH in the absorbed water 12 can be suppressed by making the absorption efficiency of CO ₂ smaller in the second absorption step than in the first absorption step, the CO ₂ and other gas components Due to the difference in solubility in water, CO ₂ can be efficiently absorbed in the absorbed water 12.

Therefore, in the first absorption process including the first static mixer 13-1 and the first absorption tower 14-1, the beer fermentation gas 11A is absorbed into the absorption water 12 with high efficiency, as will be described later. ing. The second in absorption step II-2 consisting of a second static mixer 13-2 and the second absorption tower 14-2, absorption into the absorption water 12 of CO ₂ in the first absorption step I-2 The absorption efficiency of CO _{2 into} the absorption water 12 is lower than the efficiency. As a result, in the second absorption step II-2, the CO ₂ contained in the CO ₂ gas 16A can be preferentially absorbed, by dissipating the CO ₂ absorbed into the absorbing water 12 again, a high The concentrated CO ₂ gas 16C can be obtained by concentration to a concentration.

(First mixing step I-2A)
The beer fermentation gas 11A fed to the first static mixer 13-1 is mixed with the absorbed water 12 supplied into the main body 13a in the first static mixer 13-1.
The first static mixer 13-1 is a static mixer without a drive unit. When the beer fermentation gas 11 </ b> A and the absorption water 12 are fed, the bubbles are refined by the stirring effect of the element built in the pipe, and the absorption water 12. It can be uniformly dispersed in. Absorbed water 12 and beer fermentation gas 11A are fed into first static mixer 13-1, and beer fermentation gas 11A and absorbed water 12 are vigorously gas-liquid contacted within main body 13a of first static mixer 13-1. As a result, a part of CO _{2 in} the beer fermentation gas 11A can be absorbed by the absorption water 12, and a part of the CO ₂ can be removed from the beer fermentation gas 11A.

In addition, since the solubility of CO ₂ increases as the temperature of the absorption water 12 decreases, the absorption water 12 having a low temperature of about 10 ° C. to 20 ° C. cooled by the absorption water cooler 27-1 is used for absorption in the first absorption tower 14. -1 is supplied to the first static mixer 13-1 via the first absorbed water extraction line 29-1 branched from the absorbed water circulation line 28-1.

Moreover, in the gas purification apparatus 10 which concerns on a present Example, although the 1st static mixer 13-1 is used as a mixing means, this invention is not limited to this, A line mixer as a simple absorption equipment, Other types such as a venturi scrubber can also be applied. Using these simple absorption equipment by mixing beer fermentation gas 11A and absorbing water 12, dissolved CO ₂ in the absorbent solution 12, and CO ₂ in the beer fermentation gas 11A, and the other gas components such as air Any material that can be separated can be used similarly.

The first static mixer 13-1 is compact, and it is possible to efficiently absorb the CO ₂ in the beer fermentation gas 11A, CO in the only first static mixer 13-1 beer fermentation gas 11A ₂ Since it is difficult to completely absorb the CO ₂ , a part of CO ₂ remains in the beer fermentation gas 11B discharged from the first static mixer 13-1.

(First CO ₂ absorption step I-2B)
The beer fermentation gas 11B from which CO ₂ has been partially removed by the first static mixer 13-1 is fed to the first absorption tower 14-1. Absorbed water 12 is supplied from the tower top portion 31-1 of the first absorption tower 14-1, and the beer fermentation gas 11B and nozzle 32- The absorption water 12 supplied from 1 is brought into gas-liquid contact, so that CO ₂ remaining in the beer fermentation gas 11B can be almost completely absorbed into the absorption water 12, and the tower of the first absorption tower 14-1 Around the top portion 31-1, CO ₂ remaining in the beer fermentation gas 11B can be removed.

In the present embodiment, the beer fermentation gas 11B flows from the tower bottom 34-1 side toward the tower top 31-1 side in the first absorption tower 14-1, but the present invention is limited to this. In the first absorption tower 14-1, the beer fermentation gas 11B is introduced from the vicinity of the upper part of the first absorption tower 14-1, and the rich solution 35-1 that has absorbed CO ₂ is used in the first absorption tower 14-1. You may make it extract from the tower bottom part 34-1 side of one absorption tower 14-1.

For this reason, the air 33-1 containing almost no CO ₂ is discharged as a non-absorbing gas from the top 31-1 of the first absorption tower 14-1.

In the first absorption tower 14-1, beer after a part of CO ₂ in the beer fermentation gas 11 A is dissolved in the absorption water 12 in the first static mixer 13-1 and mixed with the absorption water 12. By supplying the fermentation gas 11B, the absorption load on the absorption water 12 of CO ₂ remaining in the beer fermentation gas 11B in the first absorption tower 14-1 can be reduced, so the first absorption tower The tower height of 14-1 can be made lower than before, and the apparatus can be downsized.

Further, the absorption water 12 supplied into the first absorption tower 14-1 is in gas-liquid contact with the beer fermentation gas 11B and absorbs CO ₂ remaining in the beer fermentation gas 11B, and then the first absorption tower 14 is used. -1 is recovered as a rich solution 35-1 at the bottom 34-1.

The first absorption tower 14-1 are used as a high absorption efficiency of the absorption water 12 of CO ₂ than the second absorption tower 14-2 to be described later. This is because CO ₂ is recovered with the highest possible efficiency and supplied to the second absorption step. In the gas purification apparatus 10 according to the present embodiment, a packed tower having a packed bed is employed as the first absorption tower 14-1. By adopting a packed tower system as the first absorption tower 14-1, the first absorption tower 14-1 is more efficient in absorbing CO ₂ into the absorption water 12 than the second absorption tower 14-2 described later. Can be absorbed. In the second absorption step, the CO ₂ absorption efficiency is lower than that in the first absorption step. As a result, the CO ₂ contained in the CO ₂ gas 16A can be preferentially absorbed, is highly concentrated, it is possible to obtain a high purity CO ₂ gas 16C.

The first absorption tower 14-1, others of packed column type, as long as the high absorption efficiency of the absorption water 12 of CO ₂ than the second absorption tower 14-2, for example, shelves Other types such as a shelf tower equipped with the above may be adopted.

Further, in order to stably absorb CO ₂ in the absorption water 12 in the first static mixer 13-1 and the first absorption tower 14-1, the first absorption tower 14-1 is controlled by a pressure controller 25-2. The opening and closing of the on-off valve V3 is adjusted to maintain a constant pressure.

  Further, a liquid level controller 36-1 is provided in the tower bottom 34-1 of the first absorption tower 14-1, and the rich solution 35-1 in the tower bottom 34-1 is provided by the liquid level controller 36-1. The opening / closing of the on-off valve V4 is adjusted and controlled so that the liquid level becomes constant.

  The rich solution 35-1 recovered in the tower bottom 34-1 is extracted from the rich solution feed line 37-1, and is supplied from the tower top 38-1 of the first stripping tower 15-1 into the tower. The

(First CO ₂ gas diffusion step I-3)
The rich solution 35-1 discharged from the tower top portion 38-1 of the first diffusion tower 15-1 into the tower by the nozzle 39-1 is subjected to a decompression process in the main body 15a of the first diffusion tower 15-1. The CO ₂ dissolved in the rich solution 35-1 is removed from the rich solution 35-1. The pressure in the main body 15a of the first diffusion tower 15-1 is reduced to a pressure lower than that of the first absorption tower 14-1 or an atmospheric pressure level. By vacuum processing will be stripped gas which has been dissolved in the rich solvent 35-1, since the solubility of CO ₂ is higher than the other gas components, it can be dissipated gas mainly composed of CO ₂ .

Therefore, the rich solution 35-1 is discharged from the tower top 38-1 of the first diffusion tower 15-1 in the tower, and the separated CO ₂ gas 16A is recovered via the gas discharge line 42-1. In addition, since the beer fermentation gas 11B contains CO ₂ and air as main components, the CO ₂ gas 16A discharged from the first diffusion tower 15-1 contains some air and is discharged. The CO ₂ gas 16A is normally required purity of the purification and recycling (e.g., about 99.5 vol%) because it does not reach the, CO ₂ gas 16A is the second static mixer 13-2 and the second in the second absorption step consisting absorption column 14-2, separating the other gas components such as air in the CO ₂ gas 16A by performing a concentration operation of CO ₂ in the CO ₂ gas 16A, a higher the CO ₂ It can be concentrated to a concentration. Thereby, the CO ₂ gas 16A can usually satisfy the required purity (for example, about 99.5 vol%) when purifying and reusing.

As a method for removing CO ₂ dissolved in the rich solvent 35-1, it is not limited thereto, to separate the CO ₂ gas in the rich solvent 35-1, CO ₂ from the rich solution 35-1 As long as the water can be removed and the absorbed water 12 can be regenerated as absorbed water.

  Further, a liquid level meter 43-1 is provided inside the first diffusion tower 15-1, and the rich solution 35-1 in the first diffusion tower 15-1 is provided by the liquid level meter 43-1. Measure the amount of solution.

Further, gas dissolved in the absorption water 12 such as CO _{2 is} diffused in the first diffusion tower 15-1, and the regenerated absorption water 12 is extracted to the absorption water circulation line 28-1 by the absorption water pump 44-1. . The extracted absorbed water 12 is cooled from about 10 ° C. to about 20 ° C. by cooling water in an absorption water cooler 27-1 in order to increase the absorption efficiency, and is then placed above the first diffusion tower 15-1. Supplied and recycled. As the cooling water used for the refrigerant of the absorption water cooler 27-1, for example, cold water supplied from a chilling unit is used.

Further, a part of the water 12 cooled by the absorption water cooler 27-1 is extracted from the first absorption water extraction line 29-1 and supplied to the first static mixer 13-1 as described above. Used to dissolve CO ₂ in the beer fermentation gas 11A in the absorption water 12.

  The absorption water circulation line 28-1 is provided with a second absorption water extraction line 29-2 for extracting a part of the absorption water 12, and the first diffusion tower 15-1 has an absorption water circulation line 28 described later. -2 is provided with a second absorption water extraction line 29-4 for feeding the absorption water 12 extracted from -2 into the first diffusion tower 15-1. The absorbed water 12 is recycled through the first diffusion tower 15-1 and the absorbed water circulation line 28-1, but various trace amounts of impurities are mixed in the beer fermentation gas 11A. In order to prevent the accumulation of impurities in the apparatus and to maintain the water quality of the absorbed water 12, it is necessary to gradually replace the absorbed water 12. Therefore, a part of the absorption water 12 is extracted as blow water 46 from the second absorption water extraction line 29-2, and one of the absorption water 12 extracted from the second absorption water extraction line 29-4 as will be described later. The part is fed into the first stripping tower 15-1, and the absorption water 12 is circulated through the first stripping tower 15-1 and the absorption water circulation line 28-1.

  In addition, the second absorption water extraction line 29-2 is provided with an opening / closing valve V5, and the absorption water 12 extracted as the blow water 46 from the second absorption water extraction line 29-2 by adjusting the opening / closing valve V5. Adjust the liquid volume.

(Second concentration step II)
The second concentration step II is the same as the first concentration step I as described above, and the second gas compression step II-1, the second absorption step II-2, and the second CO ₂ gas. It consists of a diffusion process II-3.
The second gas compression step II-1, the second CO ₂ absorption step II-2, and the second CO ₂ gas emission step II-3 are the first gas compression step I-1 and the first one as described above. The same operations as those in the absorption step I-2 and the CO ₂ gas emission step I-3 are repeated.

(Second Gas Compression Step II-1, Second Absorption Step II-2, and Second CO ₂ Gas Dissipation Step II-3)
The first CO ₂ gas 16A which is dissipated in vacuo at stripping tower 15-1 is pressed again pressurized with a gas compressor 23-2, in the second static mixer 13-2, CO in the CO ₂ gas 16A Part of ₂ is absorbed by the absorption water 12. The CO ₂ gas 16B obtained by removing a part of CO ₂ from the CO ₂ gas 16A can absorb the CO ₂ remaining in the CO ₂ gas 16B in the absorption water 12 in the second absorption tower 14-2. it can.

Further, the second absorption tower 14-2 are used as a low absorption efficiency of the absorption water 12 of CO ₂ than in the first absorption tower 14-1. This is because, if CO ₂ is excessively absorbed in the absorbed water 12, the pH of the absorbed water 12 is lowered, and conversely, it is difficult to absorb CO ₂ in the absorbed water 12. Also, if other gas components be able to absorb the CO ₂ in the absorbing water 12 is absorbed at the same time, the gas to be dissipated from the absorbing water 12, other gas components other than CO ₂ since contained many, the purity of the CO ₂ in the CO ₂ gas 16C recovered from the second stripping column 15-2 is lowered. Furthermore, if the absorption efficiency of CO _{2 in} the _second absorption step is made smaller than that in the first absorption step, a decrease in pH in the absorbed water 12 can be suppressed, so that the water of CO ₂ and other gas components can be reduced. This is because CO ₂ can be efficiently absorbed in the absorption water 12 due to the difference in solubility.

In the gas purification apparatus 10 according to the present embodiment, as the second absorption tower 14-2, for example, a spray tower, a scrubber, a wet wall tower, a bubble tower, a bubble stirring tower, or the like is employed. Or the thing of the system which reduces the absorption pressure in an absorption tower is employ | adopted. For example, in the bubble column, the absorption water 12 is filled in the bubble column, and the beer fermentation gas 16B is blown into small bubbles using a gas disperser from the bottom of the bubble column, and the beer fermentation gas 16B is absorbed in the bubble column. The gas-liquid interfacial area is increased by continuously dispersing the bubbles in the water 12 as a group of bubbles, and mass transfer between the gas and liquid is performed, and gas-liquid contact is performed while the bubbles rise in the absorbed water 12. it is intended to absorb the CO ₂ Te. And the absorption water 12 is supplied from the tower top part similarly to a packed tower or a plate tower, is extracted from the tower bottom part, and is sent to the 2nd stripping tower 15-2. In addition to the above-mentioned bubble tower, the bubble tower may be in the form of an air lift, a multistage bubble tower, a packed bubble tower, a suspension bubble tower, or the like, but any form can be used. The bubble stirring tower is of a type in which beer fermentation gas 16B is blown into a bubble stirring tower equipped with a stirrer, and is finely divided into small bubbles by a stirring blade.

By adopting a spray tower, a scrubber, a wet wall tower, a bubble tower, a bubble stirring tower, or the like for the second absorption tower 14-2, the second absorption tower 14-2 is replaced with the first absorption tower 14-2. The absorption efficiency of CO _{2 into} the absorbed water 12 can be made lower than −1, and a decrease in pH in the absorbed water 12 can be suppressed. Therefore, it is possible to absorb the CO ₂ in efficiently absorbing water 12 by the difference of solubility in water and CO ₂ and other gas components.

Then, CO ₂ absorbed in the rich solution 35-2 in the second diffusion tower 15-2 is diffused and recovered as CO ₂ gas 16C. Thereby, it is possible to obtain the high-purity CO ₂ gas 16C diffused from the second stripping tower 15-2 and concentrated to a high concentration.

The operation of performing CO ₂ absorption and CO ₂ gas diffusion is performed in two stages, and CO ₂ is concentrated to a high concentration from the beer fermentation gas 11A to obtain the CO ₂ gas 16C. The CO ₂ concentration in the CO ₂ gas 16C recovered from _{2 is further} increased than the one-stage concentration in which CO ₂ absorption and CO ₂ gas diffusion are performed by the first static mixer 13-1 and the first absorption tower 14-1. The required purity (for example, about 99.5 vol%) when purifying and reusing CO ₂ can be satisfied.

The first absorption tower 14-1 and the second absorption tower 14-2 are supplied with a gas obtained by dissolving a part of CO ₂ in the absorption water 12 in advance, so that the first absorption tower 14- CO ₂ remaining in the gas is absorbed in the first and second absorption towers 14-2. Therefore, it is possible to reduce the absorption load to absorb water 12 CO ₂ in the beer fermentation gas 11A or CO ₂ gas 16A, the first absorption tower 14-1 and the second absorption tower 14-2 The tower height can be made lower than before, and the apparatus can be miniaturized.

Further, the air (non-absorbed gas) 33-2 discharged from the tower top 31-2 of the second absorption tower 14-2 may be released as it is into the atmosphere according to the gas composition. In the absorption tower 14-2, since the absorption efficiency of the CO ₂ in the CO ₂ gas 16B into the water 12 is low, the air 33-2 contains a relatively large amount of CO ₂ . Then, return to the upstream side of the gas filter (demister built-in type) 21 in the first concentration step (I) upstream of the first static mixer 13-1 from the non-absorbing gas return line 49 and process again. You may do it. Further, in the second absorption tower 14-2, the air 33-2 that has not been absorbed by the absorption water 12 is located downstream of the first static mixer 13-1 and upstream of the first absorption tower 14-1. You may make it return to.

  Further, in the gas purification apparatus 10 according to the present embodiment, since both the second static mixer 13-2 and the second absorption tower 14-2 are provided, the exhaust gas is discharged from the second absorption tower 14-2. The air 33-2 is returned to the upstream side of the first static mixer 13-1 via the non-absorbing gas return line 49, but the second absorption step is performed by the second static mixer 13-2. In this case, the air discharged from the second static mixer 13-2 may be returned upstream from the first static mixer 13-1 via the non-absorbing gas return line 49. . Further, the air discharged from the second static mixer 13-2 may be returned to the downstream side of the first static mixer 13-1 and the upstream side of the first absorption tower 14-1.

In the gas purification apparatus 10 according to the present embodiment, the CO ₂ gas 16A is pressurized again by the gas compressor 23-2 in the second gas compression step, but the air 33-, which is a non-absorbing gas, is used. When the apparatus performance such as the gas property of ₂ and the gas property of the CO ₂ gas 16A satisfies the required values, the operation pressure of the second absorption step (II-2) is set to that of the first absorption step (I-2). The operating pressure may be lowered, and the first diffusion tower 15-1 may be operated at substantially the same pressure as the second absorption tower 14-2. Thereby, since the installation of the gas compressor 23-2 can be omitted, the amount of electric power used can be reduced.

Moreover, in the gas purification apparatus 10 according to the present embodiment, both the second static mixer 13-2 and the second absorption tower 14-2 are used in the second absorption step II-2. absorption step II-2 is, when not much require a high degree of CO ₂ separation performance, as shown in FIG. 2, in the second absorption step II-2, such as the second static mixer 13-2 You may make it provide only the 2nd absorption tower 14-2, without installing simple absorption equipment. Or you may make it provide only simple absorption equipment, such as the 2nd static mixer 13-2, without installing the 2nd absorption tower 14-2.

In the present embodiment, the CO ₂ gas 16B flows in the second absorption tower 14-2 from the tower bottom 34-2 side toward the tower top 31-2 side, but the present invention is limited to this. In the second absorption tower 14-2, the CO ₂ gas 16B is introduced from the vicinity of the upper portion of the second absorption tower 14-2, and the rich solution 35-2 that has absorbed CO ₂ is introduced into the second absorption tower 14-2. You may make it extract from the tower bottom part 34-2 side of the 2nd absorption tower 14-2.

In the present embodiment, the absorption water circulation line 28-2 is provided with a second absorption water extraction line 29-4 for extracting a part of the absorption water 12, and the second diffusion tower 15-2 includes An absorption water replenishment line 48 for supplying the water 12 into the second diffusion tower 15-2 is provided. The absorption water 12 is recycled through the second diffusion tower 15-2 and the absorption water circulation line 28-2, but various trace amounts of impurities are mixed in the CO ₂ gas 11A. In order to prevent the accumulation of impurities in the apparatus and to maintain the water quality of the absorbed water 12, it is necessary to gradually replace the absorbed water 12. Therefore, a part of the absorption water 12 is extracted from the second absorption water extraction line 29-4 and is fed into the first diffusion tower 15-1 as described above. In addition, fresh fresh absorbed water 12 is supplied as make-up water 47 into the second stripping tower 15-2 from the absorbent water supply line 48, and is supplied to the second stripping tower 15-2 and the absorbed water circulation line 28-2. The absorption water 12 is circulated.

  That is, the absorption water 12 is replenished to the second diffusion tower 15-2 from outside the system, and a part of the absorption water 12 circulating in the second absorption tower 14-2 is sent to the first diffusion tower 15-1. By supplying and discharging a part of the absorption water 12 circulating through the first absorption tower 14-1 to the outside as the blow water 46, the replenishment of the absorption water 12 and the blowing outside the system are performed. be able to.

(Test example)
In addition, Table 2 shows the test results obtained by concentrating the CO ₂ -containing gas prepared to a predetermined concentration by mixing air and CO ₂ using the gas purification apparatus 10 according to this example in two stages.
The first CO ₂ absorption step was a hybrid system of the first static mixer and the first absorption tower. In addition, the second CO ₂ absorption step was performed only for the second absorption tower.

As shown in Table 2, the air concentration of the non-absorbing gas discharged from the first absorption tower is about 80 vol%, and the CO ₂ concentration of the CO ₂ gas discharged from the first diffusion tower and recovered is 98 vol. %. Moreover, the air concentration of the non-absorbing gas discharged from the second absorption tower is about 20 vol%, and the CO ₂ concentration of the CO ₂ gas discharged from the second diffusion tower and recovered is about 99.7 vol%. there were.

Therefore, the use of the gas purification device 10 according to the present embodiment, CO ₂ concentration in the CO ₂ gas from the beer fermentation gas 11A is recovered CO ₂ gas 16C about 99.7Vol% from the second stripping column 15-2 be able to.

As described above, in the gas purification apparatus 10 according to the present embodiment, the description has been made using water as the absorbent, but the present invention is not limited to this, and the beer fermentation gas 11A such as an alkaline absorbent is used. Any one that can absorb CO ₂ therein can be used as an absorbing solution. For example, using a CO ₂ absorbing solution based on amine-based solution and a CO ₂ absorbing solution and beer fermentation gas 11A is contacted交向flow, CO ₂ in the beer fermentation gas 11A, the chemical reaction (R- NH ₂ + H ₂ O + CO ₂ → R—NH ₃ HCO ₃ ) can be absorbed in the CO ₂ absorbent.

Further, in the gas purification apparatus 10 according to the present embodiment, the case where air is used as the gas component having a low solubility in water has been described. However, the present invention is not limited to this, and a gas having a low solubility in water. The same applies to the case of recovering CH ₄ , N ₂ , O ₂ , H ₂ , and He as components.

  Moreover, although the cooler is used as a low-temperature medium which heat-exchanges beer fermentation gas 11A and 16A and absorption water 12 with gas cooler 24-1, 24-2, absorption water cooler 27-1, 27-2, It is not limited to cooling water, and tap water or factory waste water may be used as long as the temperature is low.

As described above, the gas purification apparatus 10 according to the present embodiment dissolves a part of CO ₂ in the beer fermentation gas 11A in the absorption water 12 and separates CO ₂ from the beer fermentation gas 11A. 1, CO ₂ remaining in the beer fermentation gas 11B is dissolved in the absorption water 12, the first absorption tower 14-1 for separating air and CO ₂ , CO in the absorption water 12 that has absorbed CO ₂ a first diffusion column 15-1 to dissipate _2, the first CO ₂ gas 16A that is dissipated from the desorption column 15-1 and further mixed to absorb water 12, in the CO ₂ gas 16A in the absorbing water 12 A _second static mixer 13-2 for separating CO ₂ , a second absorption tower 14-2 for dissolving CO ₂ remaining in the CO ₂ gas 16B in the absorption water 12 and separating air and CO _2. , second to dissipate CO ₂ absorption water in 12 that has absorbed CO ₂ The diffusion tower 15-2 and the CO ₂ in the beer fermentation gas 11A are concentrated in two stages. In addition, the gas purifying apparatus 10 according to the present embodiment is compact and includes a first static mixer 13-1 and a second static mixer 13-2, which are simple absorption facilities suitable for processing up to a certain level. The first absorption tower 14-1 and the second absorption tower 14-2 are combined to form a hybrid absorption system.

Therefore, according to the gas purification apparatus 10 which concerns on a present Example, in the 1st static mixer 13-1, the 1st absorption tower 14-1, and the 1st stripping tower 15-1, in beer fermentation gas 11A. the CO ₂ is absorbed in the absorbing water 12, by dissipating the CO ₂ absorbed into the absorbing water 12, it is possible to increase the CO ₂ concentration in the recovered CO ₂ gas 16A. Then, the recovered CO ₂ gas 16A, a second static mixer 13-2 and the second absorption tower 14-2, a higher the CO ₂ in the absorbing water 12 in the second stripping column 15-2 Prefecture It can be absorbed by concentration. By releasing again the CO ₂ absorbed in the absorption water 12, it is possible to obtain a high-purity CO ₂ gas 16C that is further concentrated to a high concentration.
Therefore, by concentrating the CO ₂ in the beer fermentation gas 11A 2 stage, CO ₂ concentration in the CO ₂ gas 16C recovered from the second stripping column 15-2, and a first static mixer 13-1 Since it can be made higher than the one-stage concentration performed only by the first absorption tower 14-1 and the first stripping tower 15-1, the recovered CO ₂ has a required purity for purification and reuse. (For example, about 99.5 vol%) can be satisfied.

Further, in the first absorption tower 14-1 and the second absorption tower 14-2, a part of CO ₂ is dissolved in the absorption water 12 in advance, and the CO ₂ containing gas 11B after mixing with the absorption water 12 is supplied. By supplying, the absorption load on the absorption water 12 of CO ₂ remaining in the gas in the first absorption tower 14-1 and the second absorption tower 14-2 can be reduced. The tower heights of the absorption tower 14-1 and the second absorption tower 14-2 can be made lower than before, and the apparatus can be downsized.

Further, the gas purification apparatus 10 according to the present embodiment includes the first concentration step I and the second concentration step II, but the present invention is not limited to this, and CO ₂ gas. The number of concentration steps may be changed as appropriate according to the concentration ratio. Moreover, although the gas purification apparatus 10 which concerns on the Example of this invention is comprised by the 1st concentrator A and the 2nd concentrator B, the 1st concentrator A and the 2nd concentrator B, Only one of them may be installed.

In the gas purification apparatus 10 according to the present embodiment, the beer fermentation gas generated by biofermentation in the beer fermentation process is described as the CO ₂ -containing gas, but the gas purification apparatus according to the present invention is limited to this. However, it can also be used to separate CO ₂ and other gas components such as CH _{4 in} gas containing CO ₂ such as digestion gas produced by biofermentation in the methane fermentation process.

As described above, the gas purification apparatus and the gas purification method according to the present invention are suitable for use in obtaining high-concentration CO ₂ gas from a CO ₂ -containing gas such as beer fermentation gas produced by biofermentation. Yes.

DESCRIPTION OF SYMBOLS 10 Gas refiner A 1st concentrator B 2nd concentrator 11A, 11B Beer fermentation gas 12 Absorbed water 13-1 1st static mixer (mixing means)
13-2 Second static mixer (mixing means)
14-1 first absorption tower 14-2 second absorption tower 15-1 first diffusion tower 15-2 second desorption column 16A - 16C CO ₂ gas 22 gas filter (demister embedded)
23-1, 23-2 Gas compressor 24-1, 24-2 Gas cooler 25-1 to 25-4 Gas pressure detector 26-1, 26-2 Reflux passage 27-1, 27-2 Absorbing water cooler 28- DESCRIPTION OF SYMBOLS 1, 28-2 Absorption water circulation line 29-1, 29-3 1st absorption water extraction line 29-2, 29-4 2nd absorption water extraction line 31-1, 31-2, 38-1, 38- 2 Tower top 32-1, 32-2, 39-1, 39-2 Nozzle 33-1, 33-2 Air (non-absorbing gas)
34-1 and 34-2 Tower bottom 35-1 and 35-2 Rich solution 36-1 and 36-2 Liquid level controller 37-1 and 37-2 Rich solution feed line 42-1 and 42-2 Gas discharge Lines 43-1, 43-2 Liquid level meter 44-1, 44-2 Absorbing water pump 46 Blow water 47 Make-up water 48 Absorbing water replenishment line 49 Non-absorbing gas return line V1 to V5, V11 to V16

Claims (20)

And solubility in water CO ₂ is less than the gas component, the CO ₂ containing gas containing the CO ₂ mixed with absorbing water, dissolved CO ₂ in the absorption water, the CO ₂ from the CO ₂ containing gas separation to a first mixing means, dissolved CO ₂ in the first mixture was further contacted with absorbing water CO ₂ containing gas after mixing with the absorbent water by means the CO ₂ containing gas to the absorbing water One or both of the first absorption tower for separating the gas component and CO ₂ having a solubility in water smaller than CO ₂ ,
A first stripping tower for stripping CO ₂ in absorbed water that has absorbed CO ₂ in the CO ₂ -containing gas in the first absorption tower;
Mixed with further absorb water dissipated CO ₂ gas from the first stripping column, the dissolved CO ₂ absorption water, and a second mixing means for separating the CO ₂ from the CO ₂ gas, the second the CO ₂ containing gas after mixing with the absorbent water by second mixing means is further contacted with absorbing water to dissolve CO ₂ of the CO ₂ containing gas into the absorbing water, solubility in the water CO ₂ One or both of a second absorber that separates the smaller gas component and CO ₂ ;
A second stripping tower for stripping CO ₂ in the absorbed water that has absorbed CO ₂ by the second mixing means or the second absorption tower,
Gas purification system characterized by the CO ₂ in CO ₂ in the gas is dissipated from the second stripping column and high purity. In claim 1,
A first concentrating device comprising the first mixing means, the first absorption tower, and the first stripping tower; the second mixing means; the second absorption tower; and the second absorption tower. A gas purifier having one or both of a second concentrating device composed of a stripping tower. In claim 1 or 2,
The gas purification apparatus, wherein the first mixing unit and the second mixing unit are a static mixer or a line mixer. In any one of Claims 1 thru | or 3,
The gas purification apparatus, wherein the first absorption tower is a packed tower provided with a packed bed or a plate tower provided with a shelf board. In any one of Claims 1 thru | or 4,
The gas purification apparatus, wherein the second absorption tower is any one of a spray tower, a scrubber, a wet wall tower, a bubble tower, or a bubble stirring tower. In any one of Claims 1 thru | or 5,
A first absorption water circulation line and a second absorption water for circulating the absorption water in which CO ₂ is diffused in the first diffusion tower and the second diffusion tower to the first absorption tower and the second absorption tower, respectively; A gas purifier having an absorption water circulation line. In any one of claims 1 to 6,
In the second mixing means or the second absorption tower, a non-absorbing gas return line for returning the non-absorbing gas that has not been absorbed by the absorption water to the upstream side of the first mixing means or the first absorption tower. A gas purifier characterized by comprising: In any one of Claims 1 thru | or 7,
The gas purification apparatus, wherein the gas component having a solubility in water smaller than CO ₂ comprises at least one of air, CH ₄ , N ₂ , O ₂ , H ₂ , and He. In any one of Claims 1 thru | or 8,
The gas purification apparatus, wherein the CO ₂ -containing gas is a beer fermentation gas produced by biofermentation. In any one of claims 1 to 9,
In either one or both of the first absorption tower and the second absorption tower, the CO ₂ -containing gas is introduced from the upper part of either or both of the first absorption tower and the second absorption tower. In addition, the gas purifier is characterized in that the absorbed water that has absorbed CO ₂ is withdrawn from the bottom side of either one or both of the first absorption tower and the second absorption tower. And solubility in water CO ₂ is less than the gas component, the CO ₂ containing gas containing the CO ₂ mixed with absorbing water, dissolved CO ₂ in the absorption water, the CO ₂ from the CO ₂ containing gas separation a first mixing step, the CO ₂ of the CO ₂ containing gas is contacted with further absorb water CO ₂ containing gas after mixing with the absorbent solution is dissolved in the absorption water, solubility in the water to be One or both of the first CO ₂ absorption step for separating the CO _{2 from the} gas component having a gas content smaller than CO ₂ ;
A first CO ₂ gas releasing step for releasing CO ₂ in absorbed water that has absorbed CO ₂ in the CO ₂ -containing gas;
Mixed with further absorb water dissipated CO ₂ gas by the first CO ₂ gas stripping step, the absorbed water to dissolve the CO _2, and a second mixing step of separating CO ₂ from the CO ₂ gas , said CO ₂ containing gas after mixing with the absorption water further into contact with the absorbed water by dissolving CO ₂ in the CO ₂ containing gas into the absorbing water solubility CO ₂ is less than the gas component to the water And / or a _second CO ₂ absorption step for separating CO ₂ and CO ₂ ;
A second CO ₂ gas releasing step for releasing CO ₂ in the absorbed water that has absorbed CO ₂ by the second CO ₂ gas mixing step or the second CO ₂ absorption step,
Gas purification method, characterized in that the CO ₂ in the CO ₂ gas is dissipated from the second CO ₂ gas stripping step and high purity. In claim 11,
A first concentration step comprising the first mixing step, the first CO ₂ absorption step, and the first CO ₂ gas diffusion step;
The method includes any one or both of a second concentration step including the second mixing step, the second CO ₂ absorption step, and the second CO ₂ gas release step. Gas purification method. In claim 11 or 12,
The gas purification method, wherein in the first mixing step and the second mixing step, the CO ₂ -containing gas is mixed with the absorbed water using a static mixer or a line mixer. In any one of Claims 11 thru | or 13,
The gas purification method according to claim 1, wherein the first CO ₂ absorption step uses a packed tower provided with a packed bed or a plate tower provided with a shelf board. In any one of Claims 11 thru | or 14,
The gas purification method characterized in that the second CO ₂ absorption step uses any one of a spray tower, a scrubber, a wet wall tower, a bubble tower or a bubble stirring tower. In any one of Claims 11 thru | or 15,
The absorption used in the first CO ₂ absorption step and the second CO ₂ absorption step is the absorbed water from which CO ₂ has been released in the first CO ₂ gas diffusion step and the second CO ₂ gas emission step. A gas purification method characterized by circulating each as water. In any one of claims 11 to 16,
In the second mixing means or the second absorption tower, the non-absorbed gas that has not been absorbed by the absorption water is returned to the upstream side of the first mixing means or the first absorption tower and processed again. A gas purification method characterized by the above. In any one of Claims 11 thru | or 17,
A gas purification method, wherein the gas component having a solubility in water smaller than CO ₂ comprises at least one of air, CH ₄ , N ₂ , O ₂ , H ₂ , and He. In any one of claims 11 to 18,
The gas purification method, wherein the CO ₂ -containing gas is a beer fermentation gas produced by biofermentation. In any one of claims 11 to 19,
In either one or both of the first CO ₂ absorption step and the second CO ₂ absorption step, the CO ₂ -containing gas is introduced from the upper part of the absorption tower, and absorbed water that has absorbed CO ₂ is supplied to the absorption tower. A gas purification method, wherein the gas is extracted from the bottom of the column.

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