JP2013103985A - Gas purification apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas purification apparatus capable of enhancing concentration of flammable gas and capable of reducing a pressure of a liquid to which the pressure above atmospheric pressure is applied, in a process of absorbing for separation an impurity in the liquid from a mixed gas of the flammable gas and the impurity.SOLUTION: A digestion gas purification apparatus 200 produces a gas-mixed liquid W2 obtained by mixing water W1 with a raw material gas G1 after the raw material gas is formed in a microscopic bubble state, pressurizes the gas-mixed liquid W2 to dissolve the raw material gas G1 in the water W1, and removes from the gas-mixed liquid W2 an undissolved gas G2 not dissolved in the gas-mixed liquid W2 among the raw material gas G1. The gas-mixed liquid W2 is pressurized at liquid pressure lower than a dissolving pressure value of the raw material gas G1. In the bubble diameter of a microscopic bubble, a total pressure of a pressure in bubble due to surface tension of the microscopic bubble of the raw material gas G1 and the liquid pressure for pressuring the gas-mixed liquid W2 becomes equal to or larger than the dissolving pressure value.

Description

  The present invention relates to a gas separation apparatus having a low solubility from a mixture of a plurality of gases having different solubilities. For example, carbon dioxide is separated and removed from a methane mixed gas (digested gas) obtained by digesting sewage sludge. The present invention relates to a gas purification apparatus suitable for the above.

  As part of the recovery and recycling of unused energy in the sewerage field, as described in Non-Patent Document 1, sewage sludge is being converted into fuel. As a method for converting sewage sludge into fuel, recovery of methane gas by anaerobic digestion reaction of sludge has been put into practical use. As described in Non-Patent Document 2, as a method for using it, digestion gas power generation, digestion gas fuel cell, In addition to city gas substitution and supply, use as automobile fuel has been attempted as described in Non-Patent Document 3. Vehicles that can use methane gas are natural gas vehicles, and the fuel in Japan is equivalent to 13A city gas (composition example: methane 89.6%, ethane / propane / butane 10.4% (volume%, the same applies below)) It is.

  On the other hand, typical digestion gas components are 60-65% methane, 33-35% carbon dioxide, 0-2% hydrogen, 0-3% nitrogen, 0.02-0.08% hydrogen sulfide, Since there are many impurities including carbon, the calorific value is about half that of automobile fuel gas. For this reason, it is necessary to refine | purify digestion gas, to separate and remove carbon dioxide, and to raise the density | concentration of methane. Here, the main components of impurities are carbon dioxide, nitrogen, oxygen, and hydrogen sulfide as described in Non-Patent Document 4.

  Examples of a method for purifying methane gas from sewage sludge include a “wet absorption method” described in Non-Patent Document 2 and a “high-pressure water absorption method” described in Patent Document 1. The “wet absorption method” is a method in which digestion gas is brought into contact with water in a low-pressure absorption tower close to atmospheric pressure, and carbon dioxide is absorbed into water, and the gas-liquid ratio (L / G) is 2.0 or less. Methane can be concentrated to about 90% by volume. Impurities other than carbon dioxide are separated and removed by contacting with NaOH in the second absorption tower. Methane gas purified by the “high pressure water absorption method” has a composition of 98% methane, 1.0% nitrogen, 0.6% carbon dioxide, 0.2% oxygen, and 12A city gas (composition example: methane 98. 4%, nitrogen 0.3%, carbon dioxide 1.3%).

  The “high-pressure water absorption method” is a method in which the solubility of methane in water is much smaller than that of carbon dioxide and other impurities, and the change in solubility from low pressure to high pressure is small. The increasing characteristic is used (see Non-Patent Document 3). By bringing digestion gas and water into contact with each other in an absorption tower with increased pressure, the absorption capacity of carbon dioxide can be improved, and methane can be concentrated to a volume ratio of about 98% under the condition of a pressure of 0.9 MPa. Further, impurities other than carbon dioxide can be separated and removed in the same absorption tower using high-pressure conditions.

  In the gas-liquid contact flow of this system, water is supplied from a pump from the upper part of the absorption tower and pressurized digestion gas is supplied from the lower part. The water in which impurities such as carbon dioxide are dissolved after the gas-liquid contact is sent to a decompression tank, and a part of the dissolved carbon dioxide and methane is decompressed and foamed and separated from the water by reducing the pressure. Further, water in which impurities such as carbon dioxide are dissolved in the diffusion tower comes into contact with the air bubbles, and the impurities such as carbon dioxide are deaerated by moving into the air bubbles. Water in which the concentration of impurities such as carbon dioxide is further reduced by makeup water is sent again to the absorption tower and circulated. Part of the carbon dioxide and methane separated in the vacuum tank is mixed with the raw gas of the digestion gas and reused.

  As a method for improving the dissolution efficiency in gas-liquid contact, there are “fine bubble generating devices” described in Patent Document 2 and Patent Document 3. The “fine bubble generation device” of Patent Document 2 is a device that generates microbubbles having a diameter of about 50 μm by a method in which water mixed with gas is pressurized and dissolved with a two-phase flow pump and decompressed with a nozzle. The “fine bubble generating device” of Patent Document 3 is a system in which a gas is pressurized and dissolved in water with a single-phase flow pressure by an ejector, and reduced-pressure foaming is performed by a nozzle, and microbubbles are generated as in Patent Document 2. Device.

  The generated microbubbles of the raw material gas are dissolved in water in the contact tank. At that time, the microbubbles have a large specific surface area and a high ascending speed, so that high solubility is generated. As described in Non-Patent Document 5, microbubbles dissolve rapidly in a few orders of a short time from millimeter-sized bubbles and the diameter decreases at an accelerated rate, and the concentration exceeds the saturation concentration (supersaturation) with respect to the liquid pressure. It is known that gas can be dissolved.

Japanese Patent No. 4088632 Japanese Patent No. 4547445 Japanese Patent No. 4649529

Sewage Sludge Energy Utilization Investigation Committee, “Summary of Sewage Sludge Energy Utilization Survey (Part 2)-Using Sewage Sludge as an Energy Resource”, Regeneration and Utilization, VOL. 32, no. 121, 72-80, 2008 Sewage Sludge Energy Utilization Investigation Committee, “Summary of Sewage Sludge Energy Utilization Survey (Part 3)-Using Sewage Sludge as an Energy Resource”, Regeneration and Utilization, VOL. 33, no. 122, 95-102, 2009 Shiro Toyohisa, et al., Purification of digestion gas by high-pressure water absorption method and utilization as natural gas automobile fuel, Sanitary Engineering Symposium Proceedings, VOL. 13, pp. 123-126, 2005 Takahiro Yamamoto, et al., Digestion Gas Purification System by Wet Absorption Method, 43rd Sewerage Research Presentation, 407-409, 2006 Masayoshi Takahashi, Basics of Microbubbles and Cleaning of Solid Surfaces, 7th Microbubble Application Technology Lecture Materials, Chemical Engineering Society Reaction Engineering Division Reaction Field Engineering Subcommittee, November 2010

  The gas refined from the digestion gas of sewage sludge is equivalent to 12A city gas, but its calorific value is lower than that of 13A city gas. There is a need. For this reason, in order to obtain the same performance as that of a conventional natural gas vehicle, it is necessary to increase the amount of fuel mounted and the amount of engine displacement. The reason for the low calorific value is not only the difference in addition of high calorific value gas compared to 13A city gas mixed with high calorific value gas used for automobile fuel, but also carbon dioxide, nitrogen in the gas The remaining impurities such as methane and the low concentration of methane in the refined gas also have an effect. Since impurities other than methane, such as carbon dioxide, do not contribute to combustion, in order to use as fuel, impurities must be removed and the concentration of methane increased. In this regard, the “wet absorption method” has a volume ratio of methane of about 90% and the other is an impurity gas, so that it has a low calorific value for application to automobile fuel and is not practical.

  In addition, in order to obtain a product gas equivalent to 12A city gas, in the “high pressure water absorption method”, it is necessary to increase the pressure of water supplied to the absorption tower from atmospheric pressure to 0.9 MPa or more, and the power consumption of the pump is high. There are challenges. In addition, since high pressure is applied, the absorption tower and the circulation loop of the pump must be used as pressure vessels by law, increasing the equipment cost. Thus, the “high pressure water absorption method” has problems in terms of energy saving and economic efficiency.

  Patent Documents 2 and 3 “Microbubble generators” are intended to dissolve gases, and are a method of mixing a combustible gas and an impurity gas such as carbon dioxide, separating the impurity gas, and increasing the concentration of the combustible gas. Is not considered.

  In the process of absorbing and separating impurities from a mixed gas of combustible gas and impurities into a liquid pressurized to a pressure exceeding atmospheric pressure, the present invention increases the concentration of the combustible gas and reduces the pressurized pressure of the liquid. It is an object of the present invention to provide a digestion gas purification device that can be reduced.

  The gas purification apparatus of the present invention that solves the above problems is a gas purification apparatus that separates and purifies the combustible gas from a raw material gas containing a combustible gas and an impurity gas, and the impurity is more effective than the combustible gas. A gas mixture generation means for generating a gas mixture obtained by mixing the raw material gas into a liquid having high gas solubility, and pressurizing the gas mixture generated by the gas mixture generation means to pressurize the source gas And dissolving and desorbing means for desorbing undissolved undissolved gas in the gas mixture from the gas mixture. The gas mixture is pressurized at a liquid pressure lower than a dissolution pressure value at which a preset solubility is obtained, and the gas mixture generation means generates the internal pressure of the bubbles due to the surface tension of the fine bubbles of the source gas and the dissolution release. By separation means It is characterized in that the total pressure of the pressurized be liquid pressure to produce a fine bubble having a bubble diameter of greater than or equal to the dissolution pressure value.

  According to the gas purification apparatus of the present invention, the liquid pressure applied to the gas mixture can be further reduced by making the raw material gas into fine bubbles and utilizing the increase in the bubble internal pressure due to the surface tension. Therefore, a pressure vessel, a pump, etc. can be made into the simple structure for low pressure, and installation cost can be reduced. And the power consumption of a pump can be reduced and an operating cost can be reduced. Therefore, energy saving can be achieved and the economic efficiency of the gas purification apparatus can be improved. Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

The figure which shows the structure of the digestion gas purification apparatus which concerns on 1st Embodiment. The figure which shows the structure of the digestion gas purification apparatus which concerns on the modification of 1st Embodiment. The figure which shows the structure of the digestion gas purification apparatus which concerns on 2nd Embodiment. The figure which shows the structure of the digestion gas refinement | purification apparatus which concerns on the modification of 2nd Embodiment. The figure which shows the structure of the digestion gas purification apparatus which concerns on 3rd Embodiment. The figure which shows the structure of the digestion gas purification apparatus which concerns on 4th Embodiment. The figure which shows the structure of the digestion gas purification apparatus which concerns on 5th Embodiment.

<First Embodiment>
The gas purification apparatus in the present embodiment purifies high-calorie fuel gas by increasing the concentration of methane gas (combustible gas) from digestion gas (raw gas) generated when treating sludge generated at a sewage treatment plant. It is intended for digestive gas purification equipment. Hereinafter, a first embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2.

  The digestion gas refining device 200 makes the raw material gas mixed with the impurity gas such as methane gas and carbon dioxide introduced from the digestion gas recovery facility 1 into fine bubbles and dissolves them in the circulating water (liquid), and the pressure dependency of the solubility is large. In addition, carbon dioxide and other impurity gases with high solubility under high pressure conditions are separated by pressurizing and dissolving in circulating water, and methane gas (combustible gas) with low solubility and low pressure dependence is gas-liquid separated and purified to a high concentration. Perform the process.

  The digestion gas purification apparatus 200 includes a gas mixture generation unit, a dissolution / desorption unit, a volatilization unit, and a circulation unit. The gas mixture generation means performs a process of generating a gas mixture in which the raw material gas is made into fine bubbles and mixed with a liquid having a higher solubility of the impurity gas than the combustible gas. The dissolution / desorption means pressurizes the gas mixture generated by the gas mixture generation means to dissolve the raw material gas, and removes the undissolved gas undissolved in the gas mixture from the gas mixture. Process to release.

  The dissolution / desorption means pressurizes the gas mixture at a liquid pressure smaller than a dissolution pressure value at which a preset solubility of the source gas is obtained, and the gas mixture generation means is a surface of fine bubbles of the source gas. It has the structure which produces | generates the fine bubble which has a bubble diameter from which the total pressure of the bubble internal pressure by tension | tensile_strength and the liquid pressure pressurized by the said melt | dissolution desorption means becomes more than the said melt | dissolution pressure value. As will be described later, the bubble diameter may be larger corresponding to the bubble diameter that decreases with dissolution while the fine bubbles stay in the dissolution tank.

  Digestion gas purifying apparatus 200 foams the circulating water under reduced pressure, purges the impurity gas with air, and exhausts the impurity gas together with the purged air in order to remove impurity gas such as carbon dioxide and circulate water. It has a configuration. For the purified methane gas, the purification process for utilities such as drying and pressurization is omitted here.

  The digestion gas purification apparatus 200 includes a pump 2 that pressurizes circulating water as main equipment, a dissolution tank 4 (dissolution / desorption means) for dissolving the raw material gas G1 in the circulating water, and circulating water in which the raw material gas G1 is dissolved. It comprises a volatilization tank 5 for reducing the pressure and vaporizing and separating, a compressor 3 for supplying a raw material gas G1 mixed with methane and impurities, and an ejector 6 for refining and mixing the raw material gas G1 with circulating water.

  The discharge side of the pump 2 is connected to the liquid inlet of the ejector 6, the discharge side of the compressor 3 is connected to the gas inlet of the ejector 6, and the gas / liquid outlet of the ejector 6 is connected to the dissolution tank 4. Below the liquid level of the dissolution tank 4 and the volatilization tank 5 are connected by a flow resistor 44. Due to the pressure loss at the flow resistor 44, the pressure of the dissolution tank 4 is maintained and the volatilization tank 5 is depressurized.

  The liquid level of the volatilization tank 5 and the suction side of the pump 2 are connected via a volatilized water flow rate adjustment valve 48, and the liquid level of the dissolution tank 4 is connected to the purified gas channel 33 through the air vent 61. Is provided with a purified gas flow rate adjusting valve 43. An air vent 62 for taking out the impurity gas G4 is provided above the liquid level of the volatilization tank 5, and further, on the volatilization water flow path 23 that connects the volatilization tank 5 and the suction side of the pump 2 via a makeup water flow rate adjustment valve 46. A makeup water flow path 25 is connected. Below the liquid level of the volatilization tank 5, the drainage flow path 24 is connected via a drainage flow rate adjustment valve 47, and the blower 7 is connected via a purge gas flow rate adjustment valve 45.

  The circulating water W1 pressurized by the pump 2 flows through the circulating water passage 21 and flows into the liquid inlet of the ejector 6. In addition, the digestion gas source gas G1 recovered by the digestion gas recovery facility 1 passes through the source gas channel 31 and is compressed by the compressor 3, via the source gas channel 32 and the source gas flow rate adjustment valve 42. The gas is supplied to the gas inlet of the ejector 6 and is sucked from the gas inlet of the ejector 6 by the dynamic pressure of the circulating water W1. The suction of the raw material gas G1 by the circulating water W1 is obtained by increasing the flow velocity in the narrow part of the ejector 6, and the pressure loss resulting from the pressure loss at the mixing point of the raw material gas G1 is reduced from the original pressure of the circulating water W1. To do. The pump 2, the compressor 3, and the ejector 6 constitute gas mixture generation means.

  As typical operating conditions, the pressure applied to the circulating water W1 by the pump 2 is 0.7 MPa, the point at which the raw material gas G1 is mixed with the circulating water W1, and the pressure at the outlet of the ejector 6 is 0.5 MPa. Become. The raw material gas G1 is made into fine bubbles by the ejector 6, mixed with the circulating water W1, and flows into the dissolution tank 4 as raw material gas mixed water (gas mixed solution) W2.

  Since the inside of the dissolution tank 4 is substantially the same pressure as the gas-liquid outlet of the ejector 6, the solubility of the impurity component (impurity gas component) in the raw material gas G1 is increased, and the impurity component of the refined bubbles is It dissolves easily in the raw material gas mixed water W2, and the bubble diameter is reduced. As the bubble diameter decreases, the inside of the bubble is pressurized by the effect of the surface tension shown in Formula (1) described later, and the solubility of the impurity component is further increased.

  At this time, as shown in Non-Patent Document 3, methane gas has a low solubility in water and a small pressure dependency, so that the dissolved amount is small. For this reason, undissolved methane gas rises in the raw material gas mixed water W2 of the dissolution tank 4, leaves the water surface, passes through the purified gas flow path 33 from the air vent 61, and is taken out as the purified gas G2 from the digestion gas purification apparatus 200. It is.

  On the other hand, the impurity gas-dissolved water (gas-dissolved solution) W <b> 3 passes through the dissolved water channel 22, is decompressed by the flow resistor 44, and flows into the volatilization tank 5. At this time, the impurity gas G4 is foamed under reduced pressure because the pressure dependence of the solubility is large, rises in the water of the volatilization tank 5, leaves the water surface, passes through the air vent 62, and is discharged out of the digestion gas purifier 200 ( Volatilization means).

  In the volatilization tank 5, the purge air G3 fed from the lower part by the blower 7 is supplied from the bottom (air purge means). The dissolved component of the impurity gas that has not been foamed under reduced pressure is separated from the impurity volatilization water (gas volatilization liquid) W4 by contacting the bubbles of the purge air G3 and moving from the gas-liquid contact surface to the gas phase side, Like the reduced pressure foaming component, it passes through the air vent 62 and is discharged out of the digestion gas purification apparatus 200. Therefore, the amount of impurity gas dissolved from the source gas G1 in the circulating water can be increased, and the combustible gas concentration of the purified gas can be increased. Further, a part of the impurity-dissolved component that was not accompanied by the air for purging and purging under reduced pressure is discharged out of the digestion gas purifier 200 together with the drainage W6 from the drainage channel 24 (discharge unit).

  After separating and removing the impurity gas components, the impurity volatilized water W4 exits the volatilization tank 5 and is then supplied to the suction side of the pump 2 through the volatilized water passage 23 (circulation means). In the process of being supplied from the volatilization tank 5 to the pump 2, the impurity volatilization water W4 (the remaining gas volatilization liquid after a part is discharged by the discharge means) is supplied to the makeup water that does not contain the impurity gas (unmixed raw material gas) Liquid) W5 is mixed (additional replenishment means). Accordingly, the impurity concentration is further reduced, and water is repeatedly sent by the pump 2 as the circulating water W1.

  For example, in order to practically purify a high calorific value gas used for automobile fuel, it is necessary to increase the pressure of the gas mixture from atmospheric pressure to 0.9 MPa or more by the “high pressure water absorption method”. According to the digestion gas purification apparatus 200 in the present embodiment, the raw material gas G1 mixed with the circulating water W1 is made into fine bubbles, thereby adding to the liquid pressure (P0) as shown in the following formula (1). Since pressure (4σ / D) by surface tension (σ) is obtained, the pressure (P) in the bubbles is increased. For example, the bubble diameter decreases as the bubble dissolves, and the pressure increase due to the surface tension of the bubble reduced to a diameter of 1 μm reaches 0.3 MPa, and the pressure increase of the bubble reduced to a diameter of 0.7 μm reaches 0.4 MPa. .

  In so-called microbubbles having a bubble diameter of less than 100 μm and mostly around 50 μm, as described in Non-Patent Document 5, the gas flow is in line with Henry's law due to a large specific surface area, a low rising speed, and an increase in internal pressure due to surface tension. It is known that the solubility is increased and that the gas can be dissolved to a supersaturated concentration. As a result, the impurity gas can be dissolved equivalently under a lower liquid pressure condition as compared with the conventional technique shown in Patent Document 1, and the concentration of the low-combustible combustible gas is increased and the power consumption of the pump is increased. Is effective.

  When the pressure of the dissolution tank 4 is 0.5 MPa or less, the total gas pressure (bubble internal pressure + liquid pressure) is increased by increasing the surface tension by dissolving until the bubble diameter becomes 0.7 μm or less. 0.4 MPa is added and reaches 0.9 MPa or more. Further, if the pressure of the liquid at the time of dissolution can be reduced as compared with the prior art, the pressure of the circulation loop from the pump 2 to the dissolution tank 4 and the flow resistor 44 can be reduced. Reduction effect is also obtained. In the present embodiment, the pressure in the dissolution tank 4 is preferably less than 0.55 MPa.

In the bubble generation by the ejector 6 in the atmospheric pressure, the average bubble diameter is several times larger than the diameter of the microbubble, but when the bubbles generated by the ejector 6 are melted in a pressurized field (in the dissolution tank 4). The solubility is increased by Henry's law. Therefore, the bubble diameter is reduced and the region moves to the microbubble size region in a short time.
[Equation 1]
P = P0 + 4σ / D (1)

  Furthermore, by connecting the replenishment water line 25 to the liquid flow path that communicates between the volatilization tank 5 and the suction side of the pump 2, the liquid from which the impurity gas has been degassed in the volatilization tank 5 does not contain impurity gas. The make-up water W5 is added, and the concentration of the initial impurity gas of the liquid into which the raw material gas G1 is injected decreases, and the amount of dissolved impurity gas from the raw material gas G1 increases. Similarly, by discharging the waste water W6 in which the impurity gas is dissolved at a high concentration from the volatilization tank 5, the amount of the liquid in which the impurity gas from the volatilization tank 5 is dissolved is decreased, and the volatilization tank 5 is relatively transferred to the pump 2. The amount of impurity gas in the supplied liquid decreases, and the amount of impurity gas dissolved from the source gas G1 increases.

  As described above, in the present embodiment, since the source gas G1 is microbubbled and pressurized in the dissolution tank 4, the solubility of the impurity gas component in the source gas G1 is increased, and the impurity component of the micronized bubble is It dissolves easily in the raw material gas mixed water W2, and the bubble diameter is reduced. As the bubble diameter decreases, the inside of the bubble is pressurized by the effect of the surface tension shown in the above formula (1), and the solubility of the impurity component is further increased. Therefore, the impurity gas can be dissolved in the liquid under a lower pressure condition than before, the concentration of the combustible gas can be increased, the power consumption of the pump 2 can be reduced, and the equipment cost and operation cost of the digestion gas purification apparatus can be reduced. . This improves the economic efficiency of the digestion gas purification apparatus.

  As a partial modification of the present embodiment, as shown in FIG. 2, the air vent 61 and the upstream side of the compressor 3 are communicated with each other through a purified gas return channel 35, and the purified gas channel is connected to the purified gas return channel 35. It is good also as a structure which takes out a part of refinement gas G2 as a structure (undissolved gas return means) which connects 33. FIG.

  According to this configuration, the high combustible gas concentration gas (undissolved gas) G2 separated in the dissolution tank 4 is returned to the inlet side of the compressor 3 and remixed with the raw material gas G1, so that the apparent raw material gas The concentration of combustible gas in G1 increases. Therefore, if the amount of impurity gas dissolved and separated in the liquid in the dissolution tank 4 is equal, the concentration of the combustible gas in the purified gas separated in the dissolution tank 4 is further increased, and the synergistic effect of gas circulation causes digestion gas The concentration of the combustible gas G2 of the purified gas taken out from the purification apparatus 200 can be increased.

<Second Embodiment>
The second embodiment will be described with reference to FIGS. 3 and 4. In the present embodiment, the same components as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted as appropriate.

  What is characteristic in the present embodiment is that the dissolution / desorption process and the volatilization process are mainly set in two stages, and each process is repeated twice. In addition to the configuration of the first embodiment, the gas purification apparatus of the present embodiment includes a secondary gas mixture generation means, a secondary dissolution / desorption means, a secondary volatilization means, It has a dissolved gas return means.

  The secondary gas mixture generation means is a secondary gas mixture in which the undissolved gas desorbed by the dissolution and desorption means is made into microbubbles and mixed with the gas volatilization liquid generated by the volatilization means as the secondary source gas. A process for producing a liquid is performed.

  The secondary dissolution / desorption means pressurizes the secondary gas mixture generated by the secondary gas mixture generation means to dissolve the secondary source gas, and among the secondary source gases, A process of desorbing the secondary undissolved gas that has not been dissolved in the secondary gas mixture from the secondary gas mixture is performed.

  The secondary dissolution / desorption means pressurizes the secondary gas mixture at a liquid pressure smaller than the dissolution pressure value, and the secondary gas mixture generation means generates the surface of the fine bubbles of the secondary source gas. A process of generating fine bubbles having a bubble diameter in which the total pressure of the bubble internal pressure due to the tension and the liquid pressure pressurized by the second dissolution / desorption means is equal to or greater than the dissolution pressure value is performed.

  The secondary volatilization means depressurizes the secondary gas solution generated by the secondary dissolution and desorption means, foams the dissolved gas dissolved in the secondary gas solution, A process of desorbing the dissolved gas from the gas solution is performed. The second undissolved gas returning means performs a process of supplying a part of the undissolved gas desorbed by the second dissolved and desorbing means to the secondary gas mixed liquid generating means. The circulation means in this embodiment performs the process which supplies at least one part of the secondary gas volatilization liquid produced | generated by the secondary volatilization means to a gas mixed-solution production | generation means as a liquid.

  The digestion gas purification apparatus 201 includes a pump 102 for repressurizing the circulating water that comes out of the volatilization tank 5 and flows through the volatilization water passage 23 in the digestion gas purification apparatus 200 of FIG. 1, and a purification gas from the purification gas passage 33 in the circulation water. A dissolution tank 104 for re-dissolving the liquid, a volatilization tank 105 for reducing and evaporating the circulating water in which the purified gas has been redissolved, and an ejector 106 for micronizing the purified gas G2 into the circulating water and mixing them. Is done.

  The discharge side of the pump 102 is connected to the liquid inlet of the ejector 106, the purified gas flow path 33 is connected to the gas inlet of the ejector 106, and the gas / liquid outlet of the ejector 106 is connected to the dissolution tank 104. In the present embodiment, the pump 102 and the ejector 106 constitute a secondary gas mixture generation unit.

  The liquid level of the dissolution tank 104 and the volatilization tank 105 are connected by a flow resistor 144 (decompression unit), and the pressure of the dissolution tank 104 is maintained by the pressure loss at the flow resistor 144 and the volatilization tank 105 is depressurized. Is done. Below the liquid level of the volatilization tank 105 and the suction side of the pump 2 are connected by a volatilized water flow path 123 via a volatilized water flow rate adjustment valve 148, and the upper side from the liquid level of the dissolution tank 104 is connected to the purified gas flow path 133 through the air vent 161, The purified gas flow path 133 is provided with a purified gas flow rate adjustment valve 143. An air vent 162 for taking out impurity gas is provided above the liquid level of the volatilization tank 105, and a blower 107 is connected below the liquid level of the volatilization tank 105 via a purge gas flow rate adjustment valve 145.

  The impurity volatilized water (gas volatilized liquid) W4 purged with the impurity gas in the volatilization tank 5 flows through the volatilized water passage 23 and is re-pressurized by the pump 102, and flows into the liquid inlet of the ejector 106. Further, the purified gas (undissolved gas) G2 collected in the dissolution tank 4 is sucked as the secondary raw material gas from the gas inlet of the ejector 106 with the dynamic pressure of the impurity volatilized water W4. The suction of the purified gas G2 by the impurity volatilized water W4 is obtained by increasing the flow velocity at the narrow portion of the ejector 106, and the pressure at the mixing point of the purified gas G2 is the original pressure of the impurity volatilized water W4 due to the resulting pressure loss. Decrease from

  As typical operating conditions, for the pressure applied to the impurity volatilized water W4 by the pump 102 to 0.5 MPa, the point where the purified gas G2 is mixed with the impurity volatilized water W4 and the purified gas mixed water at the outlet of the ejector 106 The pressure of (secondary gas mixture) is 0.3 MPa. The purified gas G2 is refined by the ejector 106 and flows into the dissolution tank 104. Since the inside of the dissolution tank 104 is almost the same pressure as the gas-liquid outlet of the ejector 106, the solubility of the impurity component in the purified gas G2 is higher than that under atmospheric pressure conditions, and the impurity component of the refined bubbles is easy. Dissolves in the solution and the bubble diameter decreases.

  As the bubble diameter decreases, the inside of the bubble is pressurized by the effect of surface tension, and the solubility of the impurity component is further increased. Methane gas has a low solubility in water and is less dependent on pressure, so the amount dissolved is small. Therefore, the methane gas undissolved in the dissolution tank 104 (secondary undissolved gas) rises in the purified gas mixed water (secondary gas mixture) in the dissolution tank 104, leaves the water surface, and escapes from the air vent 161. From the digested gas purifying apparatus 201 as a purified gas G5 (secondary dissolution and desorption means).

  On the other hand, the impurity gas-dissolved water (secondary gas-dissolved solution) W <b> 7 passes through the dissolved water channel 122, is decompressed by the flow resistor 144, and flows into the volatilization tank 105. At this time, the impurity component (dissolved gas) is foamed under reduced pressure due to the large pressure dependency of the solubility, rises in the water of the volatilization tank 105, leaves the water surface, passes through the air vent 162, and is discharged out of the digestion gas purification apparatus 201. (Secondary volatilization means). In the volatilization tank 105, purge air fed from the lower portion by the blower 107 is supplied from the bottom. The impurity dissolved component that has not been foamed under reduced pressure comes into contact with the purge air bubbles and is separated from the impurity gas-dissolved water W7 by moving from the gas-liquid contact surface to the gas phase side. It passes through the air vent 162 and is discharged out of the digestion gas purification apparatus 201. Therefore, the amount of impurity gas dissolved from the source gas G1 in the circulating water can be increased, and the combustible gas concentration of the purified gas can be increased. The impurity volatilized water W8 (secondary gas volatilized liquid) generated in the volatilization tank 105 is supplied from the volatilized water flow path 123 to the pump 2 via the volatilized water amount adjusting valve 148.

  In the above process, the concentration of the combustible gas in the purified gas taken out from the digestion gas purification apparatus 201 can be increased by the two-stage dissolution of impurities. In this embodiment, the dissolution tank 104 corresponds to secondary dissolution / desorption means, the volatilization tank 105 corresponds to secondary volatilization means, and the volatilization water flow path 123 corresponds to circulation means.

  As a partial modification of the present embodiment, as shown in FIG. 4, the purified gas return channel 135 communicates with the air vent 161 and the upstream side of the gas inlet of the ejector 106 through the purified gas return channel 135. A part of the purified gas G5 may be taken out by connecting the path 133 (secondary undissolved gas returning means). In this refined gas flow path configuration, the concentration of the combustible gas in the purified gas G2 entering the ejector 106 is increased by returning the gas having a high combustible gas concentration separated by the air vent 161 to the gas inlet side of the ejector 106. Further, the concentration of the combustible gas in the purified gas separated in the dissolution tank 104 can be increased, and the concentration of the combustible gas in the purified gas taken out from the digestion gas purification apparatus 201 can be increased.

  Although not particularly illustrated, as a partial modification of the present embodiment, the purified gas return flow path 35 (see FIG. 2) is provided upstream of the air vent 61 and the compressor 3 as in the first embodiment. A configuration in which the purified gas channel 33 is connected to the purified gas return channel 35 (undissolved gas returning means) may be used. Moreover, it is good also as a structure which discharges some impurity volatilization water from the volatilization tank 105 while connecting a replenishment water line to the volatilization water flow path 123 between the volatilization tank 105 and the pump 2, and adding makeup water.

  According to the present embodiment, the dissolution / desorption process and the volatilization process are set in two stages, and each process is performed twice. Therefore, the impurity gas contained in a small amount in the first stage purified gas taken out from the dissolution tank 4 can be further separated and removed in the second stage, and the concentration of the combustible gas in the purified gas taken out from the tank 104 can be further increased. I can do it.

  Furthermore, the impurity gas is contained in the liquid from which the impurity gas has been degassed in the volatilization tank 5 by connecting the replenishment water line 25 to the volatilization water flow path 23 communicating with the volatilization tank 5 and the suction side of the second-stage pump 102. Supply water W5 is added, the concentration of the impurity gas in the liquid for injecting the first-stage purified gas into the second-stage dissolution tank 104 decreases, and the amount of impurity gas dissolved from the first-stage purified gas is reduced. To increase.

  Then, by discharging the waste water W6 in which the impurity gas is dissolved at a high concentration from the volatilization tank 5, the amount of the dissolved impurity gas is reduced with respect to the deaeration amount of the impurity gas in the volatilization tank 5, and relatively The amount of impurity gas in the liquid supplied from the volatilization tank 5 to the second-stage pump 102 decreases, and the amount of impurity gas dissolved from the first-stage purified gas can be increased.

  Further, by remixing the gas having a high combustible gas concentration separated in the dissolution tank 4 with the raw material gas and injecting it into the ejector 6, the apparent combustible gas concentration of the raw material gas is increased. Accordingly, if the amount of impurity gas dissolved and separated in the solution in the dissolution tank 4 is equal, the concentration of the combustible gas separated in the dissolution tank 4 is further increased, and is taken out from the remixing line due to the synergistic effect of gas circulation. Increases the combustible gas concentration of the refined gas.

  According to the present embodiment, the concentration of the combustible gas can be further increased as compared with the first embodiment. Therefore, the purification performance of the combustible gas of the digestion gas purification apparatus can be improved.

<Third Embodiment>
Next, a third embodiment will be described with reference to FIG. In the present embodiment, the same components as those in FIG. 1 or FIG. 2 are denoted by the same reference numerals, and detailed description thereof is omitted as appropriate.

  What is characteristic in the present embodiment is that a gas mixture generation means that generates fine bubbles by a pressure dissolution method is used. The digestion gas purification apparatus 202 includes a pressure-dissolution type microbubble generation apparatus as a gas mixture generation means. The microbubble generator includes a mixer 12 that mixes the circulating water W1 and the source gas G1 to generate a gas-liquid two-phase fluid, and a pump 11 that pressurizes the gas-liquid two-phase fluid and dissolves the source gas in the liquid. And a nozzle 13 for foaming the gas-liquid two-phase fluid pressure-dissolved by the pump 11 under reduced pressure.

  The mixer 12 may use an ejector, and the pump 11 may use a pump capable of feeding a gas-liquid two-phase fluid. The suction side of the pump 11 is connected to the mixer 12, the discharge side of the pump 11 is connected to the nozzle 13, and the outlet of the nozzle 13 is connected to the dissolution tank 4. Further, the air vent 61 and the mixer 12 are communicated with each other through the purified gas return channel 35, and the purified gas channel 33 is connected to the purified gas return channel 35 to take out the purified gas G2.

  Digestion gas source gas G1 recovered by the digestion gas recovery facility 1 is mixed from the mixer 12 with the circulating water W1. This gas-liquid two-phase fluid is pressurized by the pump 11, and the raw material gas mixed water W <b> 2 that is dissolved under pressure is decompressed by the nozzle 13, and fine bubbles are generated in the water in the dissolution tank 4 by the decompression foaming action.

  Bubbles generated by the apparatus described in Patent Document 2, for example, generated by the pressure dissolution method are microbubbles having a diameter of about 50 μm. As described in Non-Patent Document 5, microbubbles dissolve rapidly in a few orders of a short time from millimeter-sized bubbles and the diameter decreases at an accelerated rate, and the concentration exceeds the saturation concentration (supersaturation) with respect to the liquid pressure. It is known that gas can be dissolved. As the bubble diameter decreases, the inside of the bubble is pressurized by the effect of the surface tension shown in the above formula (1), and the solubility of the impurity component is further increased.

  At this time, as shown in Non-Patent Document 3, methane has a low solubility in water and a low pressure dependency, so that the amount of dissolution is small. For this reason, undissolved methane gas rises in the water of the dissolution tank 4, leaves the water surface, passes through the purified gas flow path 33 from the air vent 61, and is taken out as purified gas from the digestion gas purification apparatus 202. By generating finer bubbles by pressure dissolution, the internal pressure of the bubbles is increased as compared with the first embodiment. Therefore, even when the pressure of the dissolution tank 4 is low, supersaturated solubility is obtained.

  In this embodiment, the air vent 61 and the mixer 12 are communicated with each other through a purified gas return channel 35, and the purified gas channel 33 is connected to the purified gas return channel 35 to extract the purified gas G2. In this refined gas flow path configuration, by returning the gas having a high combustible gas concentration separated by the air vent 61 to the mixer 12, the concentration of the combustible gas in the raw material gas G1 is increased. The concentration of the combustible gas in the purified gas is also increased, and the concentration of the combustible gas in the purified gas taken out from the digestion gas purification apparatus 202 can be increased.

  According to this embodiment, the impurity gas can be dissolved in the liquid under a lower pressure condition than before, and the concentration of the combustible gas can be increased and the power consumption of the pump can be reduced. Operating costs can be reduced. As a result, the economic efficiency of the digestion gas purification apparatus can be improved, and the concentration of the combustible gas taken out from the digestion gas purification apparatus can be increased.

  In the present embodiment, microbubbles of a mixed gas are generated in the liquid in the dissolution tank 4 using a pressure-dissolution type microbubble generator for gas miniaturization. Microbubbles are easy to dissolve because the pressure inside the bubbles is high, so that impurity gas can be dissolved in the liquid under lower pressure conditions, increasing the concentration of flammable gas with low solubility and reducing the power consumption of the pump can do.

  Further, by remixing the gas having a high combustible gas concentration separated in the dissolution tank 4 into the raw material gas and injecting it into the mixer 12, the apparent combustible gas concentration of the raw material gas increases. Accordingly, if the amount of impurity gas dissolved and separated in the solution in the dissolution tank 4 is equal, the concentration of the combustible gas separated in the dissolution tank 4 is further increased, and is taken out from the remixing line due to the synergistic effect of gas circulation. Increases the combustible gas concentration of the refined gas.

<Fourth Embodiment>
The third embodiment will be described with reference to FIG. In the present embodiment, the same components as those in FIG. 3 or FIG. 4 are denoted by the same reference numerals, and detailed description thereof is omitted as appropriate.

  What is characteristic in this embodiment is that gas mixture generation means for generating fine bubbles by a pressure dissolution method is used for the purified gas mixing section and the remixing section.

  The digestion gas purification apparatus 203 includes two pressure-dissolving microbubble generation apparatuses as gas mixture generation means. The first microbubble generator (primary gas mixture generation means) mixes the circulating water W1 and the raw material gas G1 to generate a gas-liquid two-phase fluid, and the gas-liquid two-phase fluid. A pump 11 that pressurizes and dissolves the source gas in a liquid, and a nozzle 13 that decompresses and foams the source gas pressurized dissolved water pressurized and dissolved by the pump 11 are provided.

  Further, the second microbubble generating device (secondary gas mixture generation means) is a mixture that remixes the impurity volatilized water W4 and the purified gas G2 (secondary source gas) to generate a gas-liquid two-phase fluid. A pump 15 for pressurizing the gas-liquid two-phase fluid to dissolve the purified gas G2 in the impurity volatilization water W4, and a nozzle 16 for decompressing the purified gas pressurized dissolved water pressure-dissolved by the pump 14 under reduced pressure. Have.

  An ejector may be used for the mixer 12 and the mixer 15, and a pump capable of feeding a gas-liquid two-phase flow may be used for the pump 11 and the pump 14. The suction side of the pump 11 is connected to the mixer 12, the discharge side of the pump 11 is connected to the nozzle 13, and the outlet of the nozzle 13 is connected to the dissolution tank 4. The suction side of the pump 14 is connected to the mixer 15, the discharge side of the pump 14 is connected to the nozzle 16, and the outlet of the nozzle 16 is connected to the dissolution tank 104.

  Further, the air vent 61 and the mixer 12 are communicated with each other through the purified gas return channel 35, and the purified gas channel 33 is connected to the purified gas return channel 35 to take out the purified gas G2. The air vent 161 and the mixer 15 are communicated with each other through a purified gas return channel 135, and the purified gas channel 133 is connected to the purified gas return channel 135 to extract the purified gas G5.

  Digestion gas source gas G1 recovered by the digestion gas recovery facility 1 is mixed from the mixer 12 with the circulating water W1. This gas-liquid two-phase flow is pressurized by the pump 11, and the pressurized and dissolved raw material gas pressurized dissolved water W <b> 2 is depressurized by the nozzle 13, and fine bubbles are generated in the water in the dissolution tank 4 by the reduced pressure foaming action. On the other hand, the purified gas G2 recovered in the dissolution tank 4 is mixed from the mixer 15 into the impurity volatilization water W4.

  By generating finer bubbles (microbubbles) by pressure dissolution, the internal pressure of the bubbles is increased compared to the second embodiment, so even when the pressure of the dissolution tank 4 and the dissolution tank 104 is low, Supersaturated solubility is obtained.

  In this embodiment, since the concentration of the combustible gas in the raw material gas G1 is increased by returning the gas having a high combustible gas concentration separated by the air vent 61 to the mixer 12, the purified gas separated by the dissolution tank 4 is used. The concentration of combustible gas in G2 also increases. Then, the purified gas G2 is redissolved in the dissolution tank 104 to further remove the impurity gas, whereby the concentration of the combustible gas in the purified gas G5 exiting from the purified gas flow path 133 is increased and taken out from the digestion gas purification device 203. The concentration of combustible gas in the purified gas can be increased.

According to the present embodiment, the concentration of the combustible gas can be further increased as compared with the third embodiment. This improves the flammable gas purification performance of the digestion gas purification apparatus.
According to the present embodiment, microbubbles of a mixed gas are generated in the liquid in the dissolution tank using a pressure-dissolution type microbubble generator for gas miniaturization. Microbubbles are easy to dissolve because the pressure inside the bubbles is high, so that impurity gas can be dissolved in the liquid under lower pressure conditions, and the concentration of flammable gas with low solubility can be increased and the power consumption of the pump can be reduced. . Further, by remixing the gas having a high combustible gas concentration separated in the dissolution tank into the raw material gas and injecting it into the mixer, the apparent combustible gas concentration of the raw material gas increases. Thus, if the amount of impurity gas dissolved and separated in the liquid in the dissolution tank is equal, the concentration of the combustible gas separated in the dissolution tank is further increased, and the purified gas taken out from the remixing line due to the synergistic effect of gas circulation The concentration of flammable gas can be increased.

  In this embodiment, a method of generating by pressure dissolution is described as an example of a method of generating microbubbles. However, the method is not limited to this, and microbubbles may be generated by other methods. .

<Fifth Embodiment>
The fifth embodiment will be described with reference to FIG. In the present embodiment, the same components as those in FIGS. 1 to 6 are denoted by the same reference numerals, and detailed description thereof is omitted as appropriate.

  The digestion gas purification apparatus 200 and the digestion gas purification apparatus 202 are configured so that the flow resistor 44 is used as the power recovery mechanism (power recovery means) 17 in the first or third embodiment shown in FIG. 1, FIG. 2, or FIG. replace. The power recovery mechanism 17 is composed of a hydraulic machine such as a Pelton turbine, and is directly driven by the flow of the impurity gas dissolved water W3 from the dissolution tank 4 to the volatilization tank 5 or converted into electric power to assist the pump 102. Also good. The power recovery mechanism 17 can extract the energy of the depressurizing action using the flow resistor 44 between the dissolution tank 4 and the volatilization tank 5 as power by rotation of the water turbine and use it as auxiliary driving force of the pump 102.

  Similarly, the digestion gas purification apparatus 201 and the digestion gas purification apparatus 203 replace the flow resistor 44 with the power recovery mechanism 17 in the second or fourth embodiment shown in FIG. 3, FIG. 4, or FIG. The power recovery mechanism 17 may be directly driven or converted into electric power, and the pump 102 may be auxiliary driven. By the power recovery mechanism 17, the energy of the pressure reducing action using the flow resistor 44 between the dissolution tank 4 and the volatilization tank 5 can be taken out as power by rotation of the water turbine and used as auxiliary driving force of the pump 102. According to this embodiment, since the power consumption of a pump can be reduced, the operating cost of a digestion gas purification apparatus can be reduced. This improves the economic efficiency of the digestion gas purification apparatus.

  According to the present embodiment, the pressure drop when the pressure is reduced from the dissolution tank 4 or the second dissolution tank 104 to the volatilization tank 5 or the second volatilization tank 105 via the resistor against the flow of a valve, a nozzle or the like. By collecting it as power and using it as the driving force of the pump 2 or the second pump 102, it is possible to reduce the power consumption of the refining device and reduce the cost.

  In the first to fourth embodiments described above, the configuration in which the flow resistor 44 is provided between the dissolution tank 4 and the volatilization tank 5 to depressurize the impurity gas dissolved water W3 has been described. A spray nozzle for spraying the impurity gas dissolved water W3 is provided, and the impurity gas dissolved water W3 is sprayed from the spray nozzle to desorb the impurity gas, and the pressure reduction of the impurity gas dissolved liquid W3 is caused by the pressure loss of the spray nozzle. You may go.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various designs can be made without departing from the spirit of the present invention described in the claims. It can be changed. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to one having all the configurations described. Further, a part of the configuration of an embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of an embodiment. Furthermore, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

DESCRIPTION OF SYMBOLS 1 Digestion gas recovery equipment 2 Pump 3 Compressor 4 Dissolution tank 5 Volatilization tank 6 Ejector 7 Blower 11 Pump 12 Mixer 13 Nozzle 14 Pump 15 Mixer 16 Nozzle 17 Power recovery mechanism (power recovery means)
DESCRIPTION OF SYMBOLS 21 Circulating water flow path 22 Dissolved water flow path 23 Volatile water flow path 24 Drainage flow path 25 Replenishment water flow path 31 Raw material gas flow path 32 Raw material gas flow path 33 Purified gas flow path 34 Purge gas flow path 35 Purified gas return flow path 41 Circulation flow adjustment valve 42 Raw material gas flow rate adjustment valve 43 Purified gas flow rate adjustment valve 44 Flow resistor 45 Purge gas flow rate adjustment valve 46 Supply water flow rate adjustment valve 47 Drainage flow rate adjustment valve 48 Volatilized water flow rate adjustment valve 61 Air vent 62 Air vent 102 Pump 104 Dissolving tank 105 Volatilization tank 106 Ejector 107 Blower 121 Circulating Water Channel 122 Dissolved Water Channel 123 Volatilized Water Channel 124 Drainage Channel 125 Makeup Water Channel 131 Raw Material Gas Channel 132 Raw Material Gas Channel 133 Purified Gas Channel 134 Purge Gas Channel 135 Purified Gas Return Channel 141 Circulation flow control valve 142 Source gas Flow adjustment valve 143 Purified gas flow adjustment valve 144 Flow resistor 145 Purge gas flow adjustment valve 146 Supply water flow adjustment valve 147 Drain flow adjustment valve 148 Volatilized water flow adjustment valve 149 Purified gas return flow adjustment valve 161 Air vent 162 Air vent G1 Source gas G2 Purified gas G3 Purge air G4 Impurity gas G5 Purified gas W1 Circulating water (liquid)
W2 Raw material gas mixed water (gas mixture)
W3 Impurity gas dissolved water (gas dissolved solution)
W4 Impurity volatilization water (gas volatilization liquid)
W5 Makeup water W6 Drainage W7 Impurity gas dissolved water (secondary gas solution)
W8 Impurity volatilization water (secondary gas volatilization liquid)

Claims (23)

A gas purification apparatus for separating and purifying the combustible gas from a raw material gas containing a combustible gas and an impurity gas,
A gas mixture generation means for generating a gas mixture obtained by mixing the raw material gas into a fine bubble into a liquid having a higher solubility of the impurity gas than the combustible gas; and
The gas mixture generated by the gas mixture generation means is pressurized to dissolve the raw material gas, and undissolved undissolved gas in the gas mixed solution is desorbed from the gas mixed solution. Dissolution and desorption means;
Have
The dissolution / desorption means pressurizes the gas mixture at a liquid pressure smaller than a dissolution pressure value at which a preset solubility of the source gas is obtained,
The gas mixture generation means has a bubble diameter in which the total pressure of the bubble internal pressure due to the surface tension of the fine bubbles of the source gas and the liquid pressure pressurized by the dissolution / desorption means is equal to or greater than the dissolution pressure value. A gas purifier characterized by producing fine bubbles.   Volatilization means for depressurizing the gas solution generated by the dissolution and desorption means to foam the dissolved gas dissolved in the gas solution and desorbing the dissolved gas from the gas solution. The gas purifier according to claim 1.   The gas purification apparatus according to claim 2, further comprising a circulation unit that supplies at least a part of the gas volatilization liquid generated by the volatilization unit as the liquid to the gas mixture generation unit.   4. The gas purification apparatus according to claim 3, further comprising an undissolved gas return means for supplying a part of the undissolved gas desorbed by the dissolution and desorption means to the gas mixture generation means.   The gas purifier according to claim 3, wherein the volatilization means includes air purge means for supplying purge air to the gas solution to desorb the dissolved gas from the gas solution.   The circulation means additionally supplies a discharge means for discharging a part of the gas volatilized liquid and an unmixed liquid of the source gas to the remaining gas volatilized liquid after a part of the gas volatilized liquid is discharged by the discharge means. The gas purifier according to claim 3, further comprising additional replenishing means.   The gas mixture generation means sucks the source gas by the dynamic pressure of the liquid to generate the gas mixture, a pump that pumps the liquid to the ejector, and supplies the source gas to the ejector The gas purifier according to claim 3, further comprising a compressor that performs the operation.   The gas mixture generation means mixes the liquid and the source gas to generate a gas-liquid two-phase fluid, and pressurizes the gas-liquid two-phase fluid to dissolve the source gas in the liquid The gas purification apparatus according to claim 3, further comprising a pump and a nozzle that depressurizes the mixed solution pressurized and dissolved by the pump.   The gas purifier according to claim 7 or 8, further comprising power recovery means for recovering the pressure drop due to decompression of the gas solution as power and driving the pump auxiliary.   The gas purifier according to claim 9, wherein the power recovery means is a Pelton turbine. The secondary which produces | generates the secondary gas mixed liquid which microbubbled into the gas volatilization liquid produced | generated by the said volatilization means by making the said undissolved gas desorbed | dissolved by the said melt | dissolution desorption means into secondary gas bubbles, and mixed. Gas mixture generation means;
The secondary gas mixture generated by the secondary gas mixture generation means is pressurized to dissolve the secondary source gas, and the secondary gas mixture is converted into the secondary gas mixture. A second dissolved / desorbed means for desorbing undissolved second undissolved gas from the second gas mixture,
The secondary dissolution / desorption means pressurizes the secondary gas mixture at a liquid pressure smaller than the dissolution pressure value,
The secondary gas mixture generation means is configured such that the total pressure of the bubble internal pressure due to the surface tension of the fine bubbles of the secondary source gas and the liquid pressure pressurized by the secondary dissolution and desorption means is the dissolution. The gas purification apparatus according to claim 2, wherein fine gas bubbles having a bubble diameter equal to or greater than a pressure value are generated.   The secondary gas solution generated by the secondary dissolution and desorption means is depressurized to foam the dissolved gas dissolved in the secondary gas solution, and from the secondary gas solution. The gas purification apparatus according to claim 11, further comprising secondary volatilization means for desorbing the dissolved gas.   13. The gas purification according to claim 12, further comprising a circulation unit that supplies at least part of the secondary gas volatilization liquid generated by the secondary volatilization unit to the gas mixture generation unit as the liquid. apparatus.   And a second undissolved gas returning means for supplying a part of the second undissolved gas desorbed by the second dissolved and desorbing means to the second gas mixture generation means. The gas purifier according to claim 13.   14. The secondary volatilization means includes air purge means for supplying purge air to the secondary gas solution to desorb the dissolved gas from the secondary gas solution. The gas purifier according to 1.   The circulation means includes a discharge means for discharging a part of the secondary gas volatilization liquid, and the secondary source gas to the remaining secondary gas volatilization liquid after a part is discharged by the discharge means. The gas purifier according to claim 13, further comprising additional supply means for additionally supplying the unmixed liquid.   The secondary gas mixture generation means sucks the secondary source gas by the dynamic pressure of the gas volatilization liquid and generates the secondary gas mixture, and the gas volatilization liquid is supplied to the ejector. The gas purifier according to claim 13, further comprising a pump for pumping.   The secondary gas mixture generation means mixes the gas volatilization liquid and the secondary source gas to generate a gas-liquid two-phase fluid, pressurizes the gas-liquid two-phase fluid, and pressurizes the gas-liquid two-phase fluid. The gas purification apparatus according to claim 13, further comprising: a pump for dissolving the secondary source gas in the gas volatilization liquid; and a nozzle for decompressing and foaming the mixed liquid pressure-dissolved by the pump.   19. The gas purification apparatus according to claim 17, further comprising power recovery means for recovering, as power, a pressure drop caused by decompression of the gas solution in the secondary volatilization means and driving the pump auxiliary.   The gas purifier according to claim 19, wherein the power recovery means is a Pelton turbine.   The gas purification apparatus according to any one of claims 1 to 20, wherein the liquid pressure is less than 0.55 MPa.   The gas purification apparatus according to any one of claims 1 to 21, wherein the gas mixture generation means includes a microbubble generation apparatus that generates microbubbles obtained by microfabricating a raw material gas.   The gas according to any one of claims 11 to 22, wherein the secondary gas mixture generation unit includes a microbubble generating device that generates microbubbles obtained by microbubbles the raw material gas. Purification equipment.

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