JP4925348B2 - Method and apparatus for producing gas hydrate - Google Patents

Description

  The present invention relates to a gas hydrate manufacturing method and a gas hydrate manufacturing apparatus.

  A gas hydrate is a solid substance in which gas molecules such as hydrocarbons such as natural gas, methane, butane, ethane, and propane, oxygen, nitrogen, hydrogen, and ozone are incorporated in a cage structure of water molecules. Various uses are expected depending on the type of gas, such as transportation of gas, storage and transportation of fresh food, plant cultivation, use in carbonated beverages, and use as fuel.

  Various methods have been proposed for producing such gas hydrates (see, for example, Patent Document 1).

FIG. 10 shows an example of a method for producing a gas hydrate. When natural gas is used as the gas, after removing the oxidizing gas, the gas is supplied to the pressure vessel 35, and water is also supplied to the pressure vessel 35. Supplied. When gas and water are supplied to the pressure vessel 35, the gas is dissolved in water at a high pressure in the pressure vessel 35, and water in which this gas is dissolved at a high concentration is cooled in the pressure vessel 35, Hydrate is generated. At this time, in order to take out the generated gas hydrate from the pressure vessel 35, the gas hydrate is fed out from the pressure vessel 35 in a state of gas hydrate slurry containing water. For this reason, first, the gas hydrate slurry is separated from water in the separation tank 36, and then the gas hydrate slurry is dehydrated in the dehydration tank 37, followed by freezing, depressurization, and molding in the pelletizer 38. Gas hydrate is pelletized and stored or transported.
JP 2006-225555 A

  In producing the gas hydrate as described above, the gas hydrate is generated as a gas hydrate slurry pressurized to a high pressure in the pressure vessel 35. For this reason, the gas hydrate slurry sent out from the inside of the pressure vessel 35 suddenly drops in pressure, and gas escapes from the gas hydrate slurry as bubbles, which has a problem in the production efficiency of the gas hydrate. .

  This invention is made | formed in view of said point, and it aims at providing the manufacturing method and manufacturing apparatus of a gas hydrate which can manufacture a gas hydrate efficiently.

In the method for producing a gas hydrate according to the present invention, a gas is dissolved in water at a high concentration of a saturation level or higher under a high pressure that is higher than atmospheric pressure so that bubbles are not generated in the gas-dissolved water. The gas hydrate is generated by slowly reducing the pressure to atmospheric pressure and then cooling.

  According to the present invention, since the gas-dissolved water in which the gas is dissolved at a high concentration under high pressure is gradually reduced to atmospheric pressure so as not to generate bubbles and then cooled, the gas dissolved in water escapes. The gas hydrate can be generated in the absence of gas, and the gas hydrate can be produced efficiently.

  Further, the present invention is characterized in that, in the above production method, the gas-dissolved water is gradually depressurized to atmospheric pressure so as not to generate bubbles, and then cooled while feeding the depressurized gas-dissolved water.

  According to this invention, gas hydrate can be continuously generated from gas-dissolved water in which gas is dissolved at a high concentration, and the production efficiency of gas hydrate can be increased.

The gas hydrate manufacturing apparatus according to the present invention includes a pressurization unit 1 for pumping water, a gas injection unit 2 for injecting gas into water, and water into which gas has been injected is pumped by the pressurization unit 1. The pressure was dissolved in the pressure dissolving part 3 for dissolving the gas in water to a high concentration equal to or higher than the saturation amount under a high pressure that is a pressure greater than the atmospheric pressure, and the pressure dissolving part 3 was dissolved by the pressurization by A pressure reducing unit 4 that gradually reduces the pressure of the gas dissolved water from the inflow side to the outflow side of the gas dissolved water so as to prevent bubbles from being generated, and a gas hydrate by cooling the decompressed gas dissolved water. And a cooling unit 11 for generating

  According to the present invention, gas can be efficiently dissolved in water by the pressurizing and dissolving unit 3 by pressurization, and bubbles can be prevented from being generated in the gas-dissolved water by the depressurizing unit 4, and a stable high concentration can be obtained. Gas-dissolved water can be obtained, and the gas-dissolved water whose pressure has been reduced to atmospheric pressure is cooled by the cooling unit 11 to generate a gas hydrate in a state where the gas dissolved in water does not escape. The gas hydrate can be produced efficiently.

  Further, the present invention is characterized in that the manufacturing apparatus includes the surplus gas discharge unit 5 that discharges the surplus gas that does not dissolve in water in the pressure dissolution unit 3.

  According to the present invention, the excess gas that cannot be dissolved more than the gas dissolution saturation amount is discharged from the pressure dissolution unit 3, thereby stabilizing the ratio of gas and water in the pressure dissolution unit 3 due to the remaining surplus gas. Therefore, the pressure fluctuation can be prevented, and the gas dissolution efficiency can be kept high.

  In the manufacturing apparatus, the decompression unit 4 is provided in the flow path 6 for sending the gas-dissolved water from the pressurizing / dissolving unit 3, and the pressure of the gas-dissolved water is gradually reduced to atmospheric pressure. It is characterized by comprising a pressure regulating valve 7.

  According to the present invention, the pressure of the gas-dissolved water can be reduced by adjusting the pressure by the pressure-regulating valve 7. It is possible to stably prevent the generation of bubbles.

  Further, the present invention provides the above-described manufacturing apparatus, wherein the pressure reducing portion 4 is formed so as to reduce the pressure of the gas-dissolved water to atmospheric pressure by adjusting at least one of the channel cross-sectional area and the channel length. It is characterized by comprising a flow path 6 for feeding gas dissolved water from the dissolving part 3.

  According to the present invention, the pressure of the gas-dissolved water can be reduced by the channel cross-sectional area and the channel length of the channel 6 for sending the gas-dissolved water from the pressure-dissolving unit 3, and the structure of the apparatus can be simplified. It can be formed.

  Further, the present invention is characterized in that, in the manufacturing apparatus, the flow path 6 constituting the decompression unit 4 is formed by a single flow path.

  According to the present invention, the apparatus configuration does not become complicated as in the case where the pressure reducing unit 4 is formed by providing a plurality of flow paths.

  Further, according to the present invention, in the manufacturing apparatus described above, the sum of the pressure loss of the flow path 6 for sending the gas-dissolved water from the pressure dissolving section 3 and the pressure loss of the extension flow path 8 added to the flow path 6 is The extended flow path 8 is added to the flow path 6 so that the pressure required to pressurize the water and gas in the pressurizing and dissolving section 3 by the pressure of the water and gas pumped by It is what.

  According to the present invention, by adding the extension flow path 8 to the flow path 6, it is possible to secure the pressure in the pressurizing and dissolving section 3 with the pushing pressure from the pressurizing section 1 without using a throttle valve. The gas can be dissolved in water at this pressure.

  In the manufacturing apparatus, the pump 12 pumps water and the gas injection part 2 is provided in the front stage of the pump 12 so that the gas is dissolved in water by the stirring action of the water by the pump 12. The pump 12 is characterized in that the pressurizing part 1 and the pressurizing / dissolving part 3 are combined.

  According to the present invention, since the pressurizing unit 1 and the pressurizing / dissolving unit 3 can be formed by using the pump 12, the structure of the apparatus can be simplified.

  Further, the present invention is characterized in that, in the manufacturing apparatus described above, the pressure dissolution unit 3 is formed by a tank 13.

  According to the present invention, by forming the pressure dissolving part 3 with the tank 13, the residence time in the pressure dissolving part 3 can be lengthened, and the pump 12 forming the pressure part 1 can be downsized. It will be possible.

  According to the present invention, the gas-dissolved water in which the gas is dissolved at a high concentration under high pressure is cooled after being gently depressurized to the atmospheric pressure so as not to generate bubbles, so that the gas dissolved in the water escapes. The gas hydrate can be generated in the absence of gas, and the gas hydrate can be produced efficiently.

  Hereinafter, the best mode for carrying out the present invention will be described.

  FIG. 1 shows an example of an embodiment of the present invention, in which flow paths 15 and 6 formed by piping are respectively connected to the outflow side and the inflow side of the pressure dissolution unit 3. One end of the flow path 15 on the inflow side is connected to the pressure dissolution unit 3, and water is supplied from the other end. The pressure unit 1 is provided in the flow path 15, and the pressure unit 1 is formed by, for example, a pump 12 that pumps water to the pressure dissolving unit 3.

  The pressure dissolution unit 3 is formed of an ejector unit 40 and a surplus gas discharge unit 5. The ejector unit 40 is arranged on the upstream side of the water flow, and the surplus gas discharge unit 5 is arranged on the downstream side. The gas injection unit 2 is connected to the ejector unit 40. The gas injection unit 2 is for supplying gas to water in the ejector unit 40 and injecting it, and is connected to a gas cylinder or the like via an on-off valve 42. As this gas, natural gas, hydrocarbons such as methane, butane, ethane, and propane, and any gas such as oxygen, nitrogen, hydrogen, and ozone can be used. The surplus gas discharge part 5 is formed with a gas vent pipe 44 having a gas vent valve 43 that opens when the pressure in the surplus gas discharge part 5 becomes a predetermined pressure or more. The gas vent pipe 44 is connected to the gas injection part 2 at a position closer to the ejector part 40 than the on-off valve 42.

  The flow path 6 has one end connected to the pressure dissolution unit 3 and the other end connected to the cooling unit 11. The cooling unit 11 is formed of, for example, a container having an open upper surface, and is provided with a cooling heat exchanger 45 formed of a jacket through which a refrigerant passes. Further, the flow path 6 is provided with a decompression section 4 between a connection section to the pressure dissolution section 3 and a connection section to the cooling section 11.

  In the gas hydrate manufacturing apparatus formed as described above, when the pressurization unit 1 formed by the pump 12 is operated, water is pumped through the flow path 15 to the ejector unit 40 of the pressurization dissolution unit 3. Supplied. When water is supplied to the ejector unit 40 of the pressure dissolving unit 3 in this way, when water flows through the ejector unit 40, the gas is sucked into the ejector unit 40 from the gas injection unit 2, and the gas flows into the water. Injected. Then, the water into which the gas is injected in this way is pressurized by the pushing force of the water pumped from the pressurizing unit 1 to become a high pressure, and water and gas are pressurized in the pressurizing and dissolving unit 3. The gas can be efficiently dissolved in water at a saturated amount or more, and gas-dissolved water in which the gas is dissolved at a high concentration in water can be obtained.

  In addition, in this way, water and gas can be pressurized in the pressure dissolution section 3 to forcibly dissolve the gas efficiently, and gas dissolved water in which the gas is dissolved at a high concentration can be generated in a short time. The gas-dissolved water generated in the pressure-dissolving unit 3 can be dissolved in water in the pressure-dissolving unit 3 while sending the gas-dissolved water generated in the pressure-dissolving unit 3 to the flow path 6. Therefore, it is not necessary to form the pressure dissolving part 3 with a large volume such as a tank, and the apparatus scale can be reduced and the cost of the apparatus can be reduced.

  Here, if the total amount of gas does not dissolve in water, surplus gas that does not dissolve in water is generated in the pressurized dissolution unit 3. Therefore, the surplus gas discharge part 5 is provided in the pressure dissolving part 3 as described above, and the surplus gas remains by discharging the surplus gas that cannot be dissolved more than the gas dissolution saturation amount from the pressure dissolving part 3. It is possible to stabilize the ratio of water and gas in the pressure dissolution unit 3 to prevent pressure fluctuations and to maintain high gas dissolution efficiency. At this time, surplus gas is discharged through the degassing pipe 44 of the surplus gas discharge section 5, but since this degassing pipe 44 is connected to the gas injection section 2, it does not dissolve in water in the pressure dissolving section 3. The surplus gas can be returned to the gas injection part 2 and dissolved again in water. Therefore, the gas that has not been dissolved in the water in the pressure dissolution section 3 can be effectively used without being discarded, and when the gas is a harmful gas such as ozone, the toxic gas is discharged to the outside. Can be prevented from being contaminated.

  And the gas-dissolved water produced | generated in the pressurization melt | dissolution part 3 as mentioned above is sent out through the flow path 6, but since the gas-dissolved water is in the state pressurized by the high pressure in the pressurization melt | dissolution part 3, If discharged as it is under atmospheric pressure, bubbles may be generated in the gas-dissolved water due to a rapid pressure drop, and the amount of dissolved gas may decrease and cavitation may occur. For this reason, in the present invention, when the pressure reducing part 4 is provided in the flow path 6 and the gas-dissolved water pressurized in the pressure dissolving part 3 is sent out through the flow path 6, It is made to discharge after decompressing without generating.

  Here, when the gas-dissolved water having the same concentration as that generated in the pressure-dissolving unit 3 is depressurized from the same pressure as that pressurized in the pressure-dissolving unit 3 to the atmospheric pressure, bubbles are generated. The degree of decompression that does not occur is obtained in advance by calculation or measurement, and the pressure of the gas-dissolved water is stepwise from the side on which the gas-dissolved water flows into the outflow side at the decompression section 4 obtained in advance. Or continuously or gradually so that the pressure can be reduced to atmospheric pressure. Accordingly, the gas-dissolved water pressurized in the pressure-dissolving unit 3 is gradually reduced to atmospheric pressure at a degree of decompression at which no bubbles are generated in the decompression unit 4, and then discharged from the tip of the flow path 6 to thereby provide gas. Gas-dissolved water can be supplied to the cooling unit 11 without generating bubbles in the dissolved water, and the gas-dissolved water in which the gas is dissolved to a saturation amount or more in the pressure-dissolving unit 3 is stable and has a high concentration. Thus, it can be supplied to the cooling unit 11 in this state.

  FIG. 2 shows an example of a specific embodiment of the decompression unit 4, and a plurality of pressure regulating valves 7 ( 7a, 7b, 7c) is provided to form the decompression section 4. Thus, by forming the decompression unit 4 with the plurality of pressure regulating valves 7, the pressure of the gas dissolved water can be gradually reduced step by step at a degree of decompression that does not generate bubbles.

  Each pressure regulating valve 7a, 7b, 7c is set to depressurize at a degree of decompression that does not generate bubbles in the gas dissolved water, and this degree of decompression is set to a numerical value obtained in advance by calculation or measurement. Is. For example, when the pressurized pressure of the gas-dissolved water sent from the pressure-dissolving unit 3 to the flow path 6 is 0.5 MPa, it is found by measurement that the amount of reduced pressure at which no bubbles are generated is 0.12 MPa. Then, the pressure of the gas-dissolved water is reduced by 0.12 MPa by the pressure adjusting valve 7a and dropped to 0.38 MPa. Further, when the pressure of gas dissolved water is 0.38 MPa, if it is found by measurement that the amount of reduced pressure at which bubbles are not generated is 0.16 MPa, the pressure of the gas dissolved water is determined by the next pressure regulating valve 7b. Is reduced to 0.12 MPa and reduced to 0.22 MPa. Furthermore, when the pressure of the gas-dissolved water is 0.22 MPa, if it is found by measurement that the amount of pressure reduction at which bubbles do not occur is 0.22 MPa or more, the gas-dissolved water is detected by the next pressure regulating valve 7c. The pressure can be reduced to 0.22 MPa, the applied pressure can be reduced to 0 MPa, and the pressure can be reduced to atmospheric pressure. Note that the amount of pressure reduction by the pressure regulating valve 7 varies depending on the water temperature, gas type, dissolution concentration, pressure in the pressure dissolution unit 3, the diameter of the flow path 6, and the like. It is measured and set appropriately.

  FIG. 3 shows another example of a specific embodiment of the decompression unit 4, and a plurality of tubes 20a and 20b having different channel cross-sectional areas in the channel 6 connected to the pressure dissolution unit 3 are shown. 20c, and the decompression section 4 is formed by a plurality of pipe bodies 20a, 20b, 20c having different channel cross-sectional areas.

  In the embodiment of FIG. 3A, a plurality of tubes 20a, 20b, and 20c having different flow path cross-sectional areas, that is, different inner diameters, are integrally connected, and the gas dissolved water flows from the upstream side to the downstream side. The diameters of the tubular bodies 20a, 20b, and 20c are gradually reduced toward the side. In the embodiment of FIG. 3 (b), a plurality of tubes 20a, 20b, 20c having different inner diameters are connected and connected via a reducer 21, and the upstream side of the gas-dissolved water flows from the downstream side. The diameters of the pipe bodies 20a, 20b, and 20c are gradually reduced. Furthermore, in the embodiment of FIG. 3C, the pipe bodies 20a, 20b, and 20c that continuously decrease in diameter from the upstream side to the downstream side of the flow of the gas-dissolved water are integrally connected.

In the one of FIG. 3, each tube 20a, 20b, since the inner diameter of 20c is a _{φd 1> φd 2> φd 3} , the flow rate of each tube 20a, 20b, the gas dissolved water in 20c are _{V 1} <V ₂ <V _{3 is} satisfied, and the pressure of the gas-dissolved water in the pipes 20a, 20b, and 20c is P ₁ > P ₂ > P ₃ . Thus, a reduced pressure degree of bubble pressure P ₁ of the gas dissolved water fed from the pressure dissolution unit 3 does not occur, FIGS. 3 (a) those in is stepwise reduced pressure (b), and FIG. 3 (c) intended are those which can be lowered continuously reduced pressure, gradually to atmospheric pressure P _3.

FIG. 4 shows another example of a specific embodiment of the decompression unit 4, and when the gas-dissolved water is discharged through the channel 6 connected to the pressure dissolution unit 3, The pressure of the gas-dissolved water flowing through the gas-dissolved water gradually decreases the pressure of the gas-dissolved water at a reduced pressure rate that does not generate bubbles in the gas-dissolved water, and the pressure of the gas-dissolved water is reduced to atmospheric pressure. It is. Therefore, in the embodiment of FIG. 4, when the gas-dissolved water having the pressure P ₁ in the pressure-dissolving unit 3 is passed through the flow path 6, the gas-dissolved water is changed to P _{2 to} P _n-1 . The pressure is gradually and continuously reduced at a decompression speed at which no bubbles are generated (P ₁ > P ₂ > P _n-1 ), and the pressure P _{n of the} dissolved gas water is reduced to atmospheric pressure at the end of the flow path 6. Further, the flow path cross-sectional area and the pipe length L of the flow path 6 are set, and the pressure reducing part 4 is formed by the flow path 6 having such a flow path cross-sectional area and the pipe length L. Is.

The pipe length L can be set from the following equation. That is,
Fluid relational expression P = λ · (L / d) · (v ² / 2g)
[P is the pressure in the pressure dissolution section 3, λ is the coefficient of friction of the tube, d is the inner diameter, v is the flow velocity, and g is the acceleration]
From this, L = (P · d · 2g) / (λ · v ² ) can be derived, and the pipe length L of the flow path 6 can be obtained by calculation from this equation. As described above, the decompression section 4 can be formed only by forming the pipe length L of the flow path 6 to a predetermined length, and the structure of the apparatus can be made simpler. It is. The decompression section 4 formed by the flow path 6 having a long pipe length L can be formed by a long hose 4a as shown in FIG. 4B, for example.

  As described above, water and gas are pumped by the pressurizing unit 1 to the pressurizing / dissolving unit 3, and the gas is dissolved by pressurizing the water and gas in the pressurizing / dissolving unit 3 by the pressing pressure at this time. However, it is necessary to generate a necessary pressure in the pressurizing / dissolving portion 3 by receiving the pushing pressure. In order to secure the pressure that receives the indentation pressure from the pressurizing unit 1 as described above, it is conceivable to provide a throttle unit such as a throttle valve in the flow path 6 on the outflow side of the pressurizing and dissolving unit 3. When the throttle part is provided in the flow path 6, when the gas-dissolved water generated in the pressure-dissolving part 3 is sent to the flow path 6 and discharged, a large pressure difference occurs before and after the throttle part, and the gas-dissolved water rapidly There is a possibility that bubbles are generated in the gas-dissolved water.

  Therefore, in the embodiment of FIG. 5, the pressure loss of the flow path 6 is used to secure the pressure that receives the indentation pressure without the need to provide the throttle portion in the flow path 6. At this time, with the length of the flow path 6 of each of the above embodiments, it is difficult to secure the pressure that receives the indentation pressure due to the pressure loss of the flow path 6. An extension channel 8 is added to the part. That is, the total pressure loss including the pressure reducing part 4 of the flow path 6 is calculated, and the pressure required to pressurize water and gas in the pressure dissolving part 3 by the indentation pressure from the pressure part 1, The difference from the pressure loss of the flow path 6 is calculated, and the length of the pipe line in which the pressure loss of this difference occurs is calculated from the above formula, and the extended flow path 8 of this pipe length is changed to the flow path 6. They are added. In this way, the sum of the pressure loss of the flow path 6 and the pressure loss of the extension flow path 8 pressurizes water and gas in the pressurizing and dissolving section 3 by the pressure of water and gas being pumped by the pressurizing section 1. By adding the extension flow path 8 to the flow path 6 so that the pressure required for the pressure is reached, it is not necessary to use a throttling portion such as a throttling valve. The gas can be dissolved in water while ensuring the applied pressure.

  FIG. 6 shows a specific example of the above-described apparatus that generates gas-dissolved water in which a gas is dissolved at a high concentration in water and supplies the gas-dissolved water while reducing the pressure to atmospheric pressure without generating bubbles. Yes, water is introduced into the flow path 15 from the inlet 30. A gas injection part 2 into which gas is introduced is connected to the flow path 15, and the water into which the gas has been injected is a pressure dissolving part formed in a small capacity tank by a pressure part 1 formed by a pump. 3 is pumped. Thus, the water into which the gas has been injected is pumped to the pressure dissolving unit 3, thereby generating gas-dissolved water in which the gas is dissolved in the water in the pressure dissolving unit 3. The gas-dissolved water is sent out from the pressure dissolution unit 3 to the flow path 6, discharged from the discharge port 31 at the tip of the flow path 6, and supplied to the cooling unit 11. The flow path 6 is provided with a decompression unit 4, and the gas-dissolved water sent out from the pressure-dissolution unit 3 is decompressed to atmospheric pressure and then discharged from the discharge port 31, so that no gas bubbles are generated. Can be supplied. In the embodiment of FIG. 6, the decompression unit 4 is formed by connecting the tubular bodies 20a, 20b, and 20c having different inner diameters as shown in FIG.

  In this apparatus, by continuously operating the pressurizing unit 1 formed by the pump, the gas injection unit 2 and the pressurizing and dissolving unit 3 are continuously operated, and the decompression unit 4 continuously supplies the gas-dissolved water. The gas-dissolved water without generation of bubbles can be continuously discharged from the discharge port 31 on the outflow side of the decompression unit 4. The decompression unit 4 is provided as a part of the flow path 6 for sending the gas-dissolved water from the pressurization-dissolution unit 3, and the decompression unit 4 sequentially increases the pressure of the gas-dissolved water from the inflow side to the outflow side. Since the pressure is reduced to atmospheric pressure, the pressure reducing portion 4 can be formed as a relatively large flow path having an inner diameter of about 2 to 50 mm, for example, and the inside of the pressure reducing portion 4 is clogged even if foreign matter is mixed in. There is nothing. Further, by providing the decompression unit 4 having such a configuration, not only the laminar flow state where the Reynolds number of the gas dissolved water flowing through the decompression unit 4 is smaller than the critical Reynolds number (Re = 2320), but also the critical Reynolds number. It is possible to cope with a turbulent flow state having a larger Reynolds number. Furthermore, by forming the decompression section 4 as a flow path having a large inner diameter in this way, it is possible to increase the supply amount of dissolved gas water, and it is possible to form the decompression section 4 with only one flow path. Therefore, it is possible to form a simple apparatus configuration.

When the gas-dissolved water in which the gas is dissolved at a high concentration up to the supersaturated state as described above is supplied to the cooling unit 11, the gas-dissolved water is cooled by the cooling heat exchanger 45 provided in the cooling unit 11. Gas hydrate is generated. Here, the gas-dissolved water in which the gas is dissolved at a high concentration is generated in a high-pressure state in the pressure-dissolving unit 3, but the pressure is gradually reduced so as not to generate bubbles through the pressure-reducing unit 4, Since it is supplied to the cooling unit 11 in a state where the gas is lowered, the gas hydrate can be generated in a state in which the gas dissolved in water does not escape, and the gas hydrate can be produced efficiently. It is. For example, the pressurizing unit 1 is composed of a 20 MPa pump 12, carbon dioxide (carbon dioxide) is injected into water at 15 ° C. from the gas injection unit 2, and dissolved in water at a saturated concentration in the pressurizing dissolution unit 3. When the pressure reducing part 4 is depressurized to atmospheric pressure, carbon dioxide-dissolved water containing carbon dioxide at a concentration of about 5.5 × 10 ⁵ mg / L can be obtained. As the gas volume of the dissolved carbon dioxide, Is about 280L per 1L of water. Therefore, the gas hydrate containing a large amount of gas can be efficiently manufactured by supplying the gas dissolved in water to the cooling unit 11 in a state where it does not escape and cooling it.

  The cooling temperature of the gas-dissolved water in the cooling unit 11 is not particularly limited. For example, when cooling at a temperature of about 1 to 3 ° C., a gas hydrate slurry in which the gas hydrate is dispersed in water can be obtained. In addition, when cooled at a temperature of about −5 ° C. or lower, a solid substance in which gas hydrate is confined in water ice can be obtained.

  FIG. 7 shows another embodiment of the present invention. In the embodiment of FIG. 1, the cooling unit 11 is formed as a container having a cooling heat exchanger 45, and gas-dissolved water decompressed to atmospheric pressure is supplied to the cooling unit 11 until a predetermined amount is reached through the decompression unit 4. Then, it is cooled to produce gas hydrate, and the production of gas hydrate becomes a batch type. On the other hand, in the embodiment of FIG. 7, the cooling unit 11 is provided in the flow path 6 at a position downstream of the decompression unit 4. The cooling unit 11 can be formed, for example, by wrapping and attaching a cooling heat exchanger 45 around the outer periphery of the pipe forming the flow path 6. Other configurations are the same as those in FIG.

  In the embodiment of FIG. 7, the gas-dissolved water generated in the pressure-dissolving unit 3 in the same manner as described above is continuously sent out to the decompression unit 4 through the flow path 6, and the gas-dissolved water is decompressed. When passing through the section 4, the pressure is gradually reduced to atmospheric pressure. Thus, the gas-dissolved water decompressed to atmospheric pressure is continuously sent from the decompression unit 4 to the cooling unit 11 through the flow path 6, and is cooled when passing through the cooling unit 11 to generate a gas hydrate. Since the gas-dissolved water is cooled when continuously passing through the cooling unit 11 as described above, the gas hydrate can be continuously generated and the production efficiency of the gas hydrate can be increased. Is. In this case, since the gas hydrate needs to be in a fluid state when passing through the cooling unit 11 or after passing through the cooling unit 11, it is desirable that the gas hydrate be generated as a gas hydrate slurry having fluidity. The gas hydrate generated through the cooling unit 11 is recovered in the recovery container 48.

  FIG. 8 shows still another embodiment of the present invention. The pressurizing part 1 is formed by the pump 12 and the gas injection part 2 is provided in the flow path 15 upstream of the pump 12. It is. In this case, when the pump 12 is operated and the water in the flow path 15 is sucked into the pump 12, the gas is sucked into the flow path 15 from the gas injection part 2 when the water flows in the flow path 15. Gas is injected into the water. When the water into which the gas has been injected is sucked into the pump 12, the gas is efficiently saturated in the water by the stirring action of the water in the pump 12 and the pressure of the water pumped from the pump 12. Dissolved in Further, the surplus gas that cannot be dissolved exceeding the gas dissolution saturation amount is discharged from the surplus gas discharge unit 5. The gas-dissolved water in which the gas is dissolved in such a high concentration is supplied to the decompression unit 4 and decompressed to atmospheric pressure, and then supplied to the cooling unit 11 to be cooled, thereby generating a gas hydrate.

  Therefore, in the embodiment of FIG. 8, the pressurization unit 1 for pumping water with the pump 12 and the pressurization dissolution unit 3 for dissolving the gas in water at a high concentration by pressurizing the water injected with gas. Thus, it is possible to eliminate the need to provide the ejector 40 as in the embodiment of FIG. That is, the pressurizing unit 1 and the pressurizing / dissolving unit 3 can be formed by using the pump 12, and the configuration of the apparatus can be simplified.

  FIG. 9 shows still another embodiment of the present invention. In this embodiment, the pressure dissolving part 3 is formed by the tank 13. When it is necessary to generate a large amount of gas-dissolved water when generating gas-dissolved water in which gas is dissolved at a high concentration in the pressure-dissolving unit 3, the inside of the pressure-dissolving unit 3 as in the above embodiments. When the gas is dissolved in the water while allowing water to pass through, the pump 12 forming the pressurizing unit 1 requires a high pressure and high flow rate, and the efficiency is deteriorated. Therefore, in the embodiment of FIG. 9, the pressure dissolving unit 3 is formed by a tank 13 having a large volume, and the gas injection unit 2 is provided in the tank 13 to supply gas into the tank 13.

  In this case, the water pumped by the pump 12 of the pressurizing unit 1 is sent to the tank 13 forming the pressurizing and dissolving unit 3, and the gas is dissolved in the water remaining in the tank 13, and the gas is dissolved in the tank 13. Water is generated. Since the gas only needs to be dissolved in the state of being retained in the tank 13 as described above, the pump 12 can be reduced in size. The gas-dissolved water generated in the tank 13 is supplied to the decompression unit 4 and depressurized to atmospheric pressure, and then supplied to the cooling unit 11 to be cooled to generate gas hydrate.

It is the schematic which shows an example of embodiment of this invention. It is the schematic which shows an example of the pressure reduction part in embodiment same as the above. The other example of the pressure reduction part in embodiment same as the above is shown, (a) (b) (c) is a schematic diagram, respectively. The other example of the pressure reduction part in embodiment same as the above is shown, (a) is a schematic diagram, (b) is a perspective view. It is the schematic which shows another example of the pressure reduction part in embodiment same as the above. (A) (b) is a perspective view which shows an example of embodiment of this invention. It is the schematic which shows another example of embodiment of this invention. It is the schematic which shows another example of embodiment of this invention. It is the schematic which shows another example of embodiment of this invention. It is the schematic which shows a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pressurization part 2 Gas injection part 3 Pressurization melt | dissolution part 4 Depressurization part 5 Excess gas discharge part 6 Flow path 7 Pressure control valve 8 Extension flow path 11 Cooling part 12 Pump 13 Tank

Claims (10)

Under high pressure is greater than atmospheric pressure, water was dissolved gas in a high concentration in the concentration of more than saturation amount, after the bubble the gas dissolved water was reduced slowly to atmospheric pressure so as not to generate, cooled And producing a gas hydrate.   The method for producing a gas hydrate according to claim 1, wherein the gas-dissolved water is gradually reduced to atmospheric pressure so as not to generate bubbles, and then cooled while feeding the decompressed gas-dissolved water. A pressure unit that pumps water, a gas injection unit that injects gas into water , and a high pressure that is greater than atmospheric pressure by pressurizing the water into which gas has been injected by the pressurization unit. The pressure dissolution part for dissolving the gas in water to a high concentration equal to or higher than the saturation amount and the pressure of the gas dissolved water in which the gas is dissolved in the pressure dissolution part are changed from the inflow side to the outflow side of the gas dissolution water. A gas hydride comprising: a decompression section that gradually reduces pressure so that bubbles are not generated sequentially to atmospheric pressure; and a cooling section that generates gas hydrate by cooling the decompressed gas-dissolved water. Rate manufacturing equipment.   The apparatus for producing a gas hydrate according to claim 3, further comprising a surplus gas discharge unit that discharges a surplus gas that does not dissolve in water in the pressure dissolution unit.   The depressurization unit is provided in a flow path for sending the gas-dissolved water from the pressure-dissolving unit, and comprises a plurality of pressure regulating valves that stepwise reduce the pressure of the gas-dissolved water to atmospheric pressure. The apparatus for producing a gas hydrate according to claim 3 or 4.   The pressure reducing part is a flow path for sending the gas dissolved water from the pressure dissolving part formed so as to reduce the pressure of the gas dissolved water to atmospheric pressure by adjusting at least one of the channel cross-sectional area and the channel length. The apparatus for producing a gas hydrate according to claim 3 or 4, wherein the apparatus is configured.   The apparatus for producing a gas hydrate according to claim 5 or 6, wherein the decompression unit is formed by one flow path.   The sum of the pressure loss of the flow path for sending the gas-dissolved water from the pressure-dissolving section and the pressure loss of the extension flow path added to this flow path is the inside of the pressure-dissolving section by the pressure of water and gas pushed in by the pressurizing section. The gas hydrate according to any one of claims 3 to 7, wherein an extension flow path is added to the flow path so as to obtain a pressure required to pressurize water and gas. Manufacturing equipment.   By pumping water with the pump and providing a gas injection part in the front stage of the pump so that the gas is dissolved in water by the stirring action of the water by the pump, the pressure part and the gas dissolving part are combined with the pump The gas hydrate manufacturing apparatus according to any one of claims 3 to 8, wherein the gas hydrate manufacturing apparatus is configured as described above.   The gas hydrate manufacturing apparatus according to any one of claims 3 to 9, wherein the pressure dissolving portion is formed by a tank.

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