JP2003082371A - Gas hydrate-forming container, apparatus and method for producing gas hydrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas hydrate-forming container, an apparatus and a method for producing a gas hydrate which can stably form the gas hydrate at a high speed and, simultaneously, in a large amount, and can increase the production efficiency of the gas hydrate. SOLUTION: A gas hydrate-forming container 10a for forming a gas hydrate by hydrating a gas containing a hydrate-forming substance with water is constituted by having a container body 11 and a water droplet-forming device 12a for forming water droplets wd and dropping them in the container body 11, the water droplets-forming device 12a having a bottom portion in which a number of holes h are formed, a water storage zone R for storing water inside, and an adjustable pressurizer 14 provided within the water storage zone R to pressurize and depressurize the water within the water storage zone R in a specified cycle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas hydrate producing container for producing a gas hydrate by hydrating a gas containing a hydrate-forming substance (e.g. methane), a gas hydrate production apparatus, and a gas hydrate producing apparatus therefor. Gas hydrate manufacturing method.

[0002]

2. Description of the Related Art At present, as a method of storing and transporting natural gas containing hydrocarbons such as methane as a main component, natural gas is collected from a gas field and then cooled to a liquefaction temperature to obtain liquefied natural gas (LNG). Generally, the method of storing and transporting in a stored state. However, for example, in the case of methane, cryogenic conditions such as -162 ° C are required for liquefaction, and in order to store and transport while maintaining such conditions, a special storage device, a special LNG ship, etc. Transportation means are required. Since very high cost is required to manufacture, maintain, and manage such devices, a low-cost storage / transportation method that replaces the above method has been earnestly studied. As a result of these studies, a method of hydrating natural gas to produce a hydrate in a solid state and storing and transporting the hydrate in the solid state has been found, which has been particularly promising in recent years. This method does not require cryogenic conditions such as when handling LNG, and because it is a solid, it is relatively easy to handle, and existing refrigeration equipment or existing container vessels that are slightly improved are stored respectively. It is expected that it can be used as a device or a means of transportation and the cost can be significantly reduced.

The hydrate of natural gas (hereinafter referred to as "gas hydrate") is a kind of clathrate compound (clathrate compound) and is shown in FIGS. 9 (a) and 9 (b). As shown in the figure, in a three-dimensional cage clathrate (clathrate) formed by a plurality of water molecules (H ₂ O), a hydrate-forming substance that constitutes each component of natural gas, that is, methane (CH ₄ ) And other molecules are included to form a crystal structure. In addition, FIG. 9A shows a water molecule H ₂ O.
Shows the case of forming a dodecahedron, and FIG. 9B shows the case of forming a dodecahedron. In addition, methane molecule CH ₄ is shown as an example of the hydrate-forming substance. The intermolecular distance between the constituent molecules of the natural gas clathrated by the clathrate is shorter than the intermolecular distance in the gas cylinder when the natural gas is charged at a high pressure. This means that natural gas can produce a tightly packed solid, eg under conditions where methane hydrate can be stably present, ie at −30 ° C. under atmospheric pressure (about 0.1 MPa). The volume can be about 1/170 as compared with the gas state. As described above, the gas hydrate can be produced under the temperature and pressure conditions that are relatively easy to obtain, and can be stably stored.

In the above method, the natural gas after being received from the gas field is almost free from methane by removing acid gases such as carbon dioxide (CO ₂ ) and hydrogen sulfide (H ₂ S) in the acid gas removing step. After that, it is brought to a low temperature and high pressure state and hydrated in the hydrate production process to become a gas hydrate. In this gas hydrate, unreacted water mixed in the subsequent dehydration step is removed, and further, through a cooling step and a pressure reducing step, a solid state product gas hydrate adjusted to a predetermined temperature and pressure is obtained. It is enclosed in a container such as a container and stored in a storage device. During transportation,
This container will be loaded as it is on a transportation means such as a container ship and transported to the destination. After landing at the destination, the gas hydrate is returned to the state of natural gas through a hydrate decomposition process and sent to each supply place.

As a gas hydrate production apparatus used in the hydrate production process, for example, a so-called spray type production apparatus as shown in FIG. 10 is used. This gas hydrate production device
Generation container 10 whose inside is set to predetermined pressure and temperature conditions
1. A water phase L is formed at the bottom of 1, and natural gas (gas hydrate forming substance) is supplied to this water phase L as bubbles K, and a gas phase G filled with natural gas therein is overheated from above. The cooling water is sprayed in a spray form (see reference sign SP).
Part of the natural gas introduced into the water phase L is hydrated on the outer surface of the bubbles K, that is, the gas-liquid interface, and gas hydrate is generated. On the other hand, the water sprayed in the gas phase G instantly undergoes a hydration reaction with the gas in the gas phase G to generate a gas hydrate, and falls on the water phase L, that is, on the water surface. Furthermore, even at the water surface, that is, at the gas-liquid interface between the water phase L and the gas phase G,
Gas hydrate is produced. Since the generated gas hydrate has a lower specific gravity than water, it is floating on the water surface. This gas hydrate is extracted together with water through an extraction pipe line (not shown) provided near the water surface and sent to the next dehydration step.

[0006]

Such a spray type gas hydrate production apparatus has an advantage that it can be produced at a high speed, but has the following problems. In spraying water droplets, the sprayed water droplets spread conically from the spray nozzle. Therefore, a region where water droplets are not sprayed, that is, a useless space that cannot contribute to the generation of gas hydrate occurs. Since the gas hydrate generation container needs to be a pressure container, its shape cannot be changed indiscriminately.Therefore, the lateral position of the spray device becomes a space that cannot be effectively used for the generation of gas hydrate. Was there. In the example of FIG. 10, the outer peripheral portion on the top side of the production container 101 is such a useless space. Also, since the water droplets spread in a conical shape, they may collide with each other or collide with the inner wall surface of the generation container, and such water droplets cannot be effectively used for the generation of gas hydrate. It was. That is, the production efficiency has been reduced. Furthermore, it is actually difficult to make the temperature conditions and the like completely uniform at all locations in the production container, and there will inevitably be differences depending on the locations. As a result, the production rate and production amount of gas hydrate differ depending on the place, and it is difficult to continuously produce a stable production amount.

The present invention has been made in view of the above circumstances, and a gas hydrate producing container capable of stably producing a large amount of gas hydrate at a high speed and enhancing the production efficiency of gas hydrate. An object of the present invention is to provide a gas hydrate manufacturing apparatus and a manufacturing method.

[0008]

The invention according to claim 1 is a gas hydrate producing container for producing a gas hydrate by hydrating a gas containing a hydrate-forming substance with water. The container main body, and a water drop generating means that is provided on the upper side of the container main body and generates water drops to drop into the container main body, the water drop generating means has a bottom portion having a large number of holes formed therein. The water storage unit has therein a water storage unit for storing water therein, and a pressurizing / depressurizing unit provided in the water storage unit for pressurizing / depressurizing the water in the water storage unit at a predetermined cycle.

As described above, since the water in the water reservoir is pressurized and depressurized by the depressurizing means at a predetermined cycle,
The water droplets having a substantially constant size can be regularly dropped from the holes so as to correspond to this cycle. Further, since the water droplets can be dropped almost vertically, the water droplets hardly contact or collide with the inner wall surface of the container body,
The container body can be dropped stably.

The invention according to claim 2 is the gas hydrate generating container according to claim 1, characterized in that the pressurizing / depressurizing means is made of a piezoelectric material.

As described above, since the pressurizing / depressurizing means is composed of the piezoelectric material, the shape can be changed with a very high response characteristic with respect to the frequency of the applied alternating current, and the water in the water reservoir can be changed. Accurate pressurization and depressurization can be performed in a stable cycle.

The invention according to claim 3 is the gas hydrate generating container according to claim 1 or 2, wherein the cooling means cools the lower side of the water droplet generating means from the outer peripheral side of the container body. It is characterized by having.

As described above, since the cooling means for cooling the lower side of the water droplet generating means from the outer peripheral side of the container body is provided, when the gas hydrate is generated in the dropped water droplets with a simple structure. The heat of hydration generated in the can be removed with high efficiency.

The invention according to claim 4 is the gas hydrate production container according to any one of claims 1 to 3, wherein the hole diameter of the hole is changed between the outer peripheral side and the inner side of the water storage part. It is characterized by being

As described above, since the diameters of the holes are changed between the outer peripheral side and the inner side of the water storage portion, even if there is a difference in the temperature / pressure conditions between the outer peripheral side and the inner side in the production container, the water droplets to be dripped. Can be set to a size that can properly generate gas hydrate under each condition.

According to a fifth aspect of the present invention, there is provided the gas hydrate producing container according to any one of the first to fourth aspects, wherein the water storage section is divided into an outer peripheral side and an inner side, and the pressurizing / depressurizing means. Is independently provided in each of the outer peripheral side and the inner side water reservoir as the first and second pressurizing / depressurizing means.

As described above, since the water storage section is divided into the outer peripheral side and the inner side, and the pressurizing / depressurizing means is independently provided in each of the outer peripheral side and the inner side water storage sections, the outer peripheral side and the inner side in the production container are Even if there is a difference in temperature and pressure conditions on the peripheral side, the phase and cycle of the water droplets to be dropped can be changed so that gas hydrate can be generated appropriately under each condition Timing and number density can be set.

The invention according to claim 6 is a gas hydrate production apparatus, wherein the gas hydrate producing container according to any one of claims 1 to 5 and water supply means for supplying water to the water storage section. A gas introducing means for introducing a gas containing a hydrate-forming substance into the container body and forming a gas phase in the container body; and withdrawing the generated gas hydrate from the gas hydrate producing container. The output means is provided.

Since the apparatus for producing gas hydrate is configured in this manner, the gas hydrate can be suitably produced using the gas hydrate producing container according to any one of claims 1 to 5.

The invention according to claim 7 is the apparatus for producing gas hydrate according to claim 6, wherein water is introduced into the container body, and water is introduced below the gas phase in the container body. It is characterized by comprising water introducing means for forming a phase and second gas introducing means for introducing the gas as bubbles into the aqueous phase.

As described above, since the gas phase and the gas phase are formed in the gas hydrate producing container and the gas is introduced into the water phase as bubbles, the gas phase and the gas phase are brought into contact with each other. Gas hydrate can also be produced in the partial and aqueous phases.

The invention according to claim 8 is a method for producing gas hydrate using the gas hydrate production apparatus according to claim 6 or 7, wherein the first pressurizing and depressurizing means and the first The second pressurizing and depressurizing means shifts the phases of each other to pressurize and depressurize the water in the water storage section.

The invention described in claim 9 is the same as in claim 6.
Or it is a manufacturing method of the gas hydrate using the gas hydrate manufacturing apparatus of Claim 7, Comprising: The said 1st pressurizing / depressurizing means and the said 2nd pressurizing / depressurizing means change a mutual cycle, and are said. A feature of the present invention is that the water in the water storage portion is pressurized and depressurized.

As described above, the phase and the cycle of the water drops to be dropped are changed so that the gas hydrate can be appropriately generated under each condition, so that the drop timing and the number density of the water drops are set. Even if there is a difference in temperature / pressure conditions between the outer peripheral side and the inner peripheral side in the production container, the gas hydrate can be appropriately produced under each condition.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] A first embodiment of the present invention.
Before explaining the conditions, this gas hydrate manufacturing equipment
To use natural gas as product hydrate
The flow of the series will be described with reference to FIG. In this figure
As shown in the figure, natural gas received from gas fields
Is the raw material gas first received in the raw material gas receiving tank A.
It is put in and stored once. From here, acid gas removal equipment
Carbon dioxide (CO ₂)
And hydrogen sulfide (H₂Acid gases such as S) are removed. Acidic
For removing the gas, for example, the raw material gas is lime (CaO) or the like.
Blow into the alkaline reagent, and use this alkaline reagent and acid gas.
This is done by reacting with the ingredients. Acid gas was removed
Almost all of the components of the source gas are methane.
It This raw material gas is then conducted to the hydrate manufacturing apparatus C.
It is put in and the conditions for producing hydrate at room temperature and high pressure are met.
It is then compressed and cooled to hydrate and becomes a gas hydrate.
It "Hydrate generation conditions" here means methane
Conditions under which hydrate can be produced, that is, 2 to 10 ° C
At a temperature of about 4 MPa and a pressure of 4 MPa or more
These are temperature and pressure conditions.

Since this gas hydrate is in the form of a slurry in which unreacted water remains, excess water is removed and dehydrated in the next dehydrator D. The dehydration here is mechanical / physical dehydration using a screw press, a centrifugal separator, a nip roller, or the like. Since water may still remain in the gas hydrate dehydrated as described above, chemical dehydration is performed in the next hydration dehydrator E. That is, the raw material gas is further brought into contact with excess water for hydration to reduce the water content water content in the gas hydrate, resulting in further dehydration. In addition, here, the dehydrator D for mechanical / physical dehydration and the hydration dehydrator E for chemical dehydration are separately provided, but these dehydrations are collectively performed. It is possible to provide a dehydrating device capable of performing the above, that is, a device in which the dehydrating device D and the hydration dehydrating device E are integrated. The dehydrated gas hydrate is cooled by the cooling device F1 and depressurized by the depressurizing device F2, so that the hydrate storage condition is kept at low temperature and normal pressure. The hydrate storage condition is a temperature / pressure condition such that the temperature is about −20 to −40 ° C. and the pressure is atmospheric pressure (about 0.1 MPa). In this state, the product gas hydrate is enclosed in a container such as a container, sent to a storage device (not shown), and stored therein.

The present embodiment relates to the above-described gas hydrate production apparatus C and a gas hydrate production container used for the apparatus. In the present embodiment and each of the embodiments described later, the configuration of the gas hydrate production container, which is one component of the gas hydrate production apparatus, is changed. Will be shown as.

The gas hydrate production apparatus C according to this embodiment, as shown in FIG. 1, is a production container (gas hydrate production container) 10a for producing a gas hydrate GH by hydrating a raw material gas, and A gas introducing pipe (gas introducing means) 21 for introducing the raw material gas into the production container 10a, a water introducing pipe (water introducing means) 23 for introducing water into the production container 10a, and A water pumping line (water supply unit) 25 for supplying water to the water droplet generation device 12 and a hydrate extraction line (extraction unit) 31 for extracting the generated gas hydrate GH are provided.

The production container 10a is provided with a container body 11 and a water drop producing device (water drop producing means) 12 provided on the upper top side in the container body 11. Container body 11
Is a sealed pressure vessel, which reacts with a predetermined amount of injected water and the raw material gas, that is, hydrates it to generate a gas hydrate GH. This container body 11
Inside, a water phase W filled with water and a gas phase G filled with a raw material gas are formed above the water phase W. A hydrate extraction conduit 31 for extracting the generated gas hydrate GH to the outside of the generation container 10a is attached near the water surface S of the water phase W.

The production container 10a is provided with a cooling means (not shown) for cooling the water phase W. An example of a suitable cooling means is a cooling coil, but it goes without saying that a cooling means having another configuration may be used. Although not shown, a recovery means for recovering the unreacted gas in the gas phase G is connected to the production container 10a. The unreacted gas recovered by this recovery means may be mixed with the raw material gas again and used cyclically,
It may be used for other purposes. Further, a stirring device for stirring the water phase W to promote hydration of water and gas may be provided. By stirring the water phase W with a stirrer, the gas in the gas phase G is dispersed in the water phase W, and the water surface S, that is, the gas-liquid contact surface is increased, so that the gas hydrate is efficiently generated. be able to.

The inside of the production container 10a is maintained under the temperature and pressure conditions where the gas hydrate GH can be produced, that is, under the gas hydrate production conditions, by the cooling means and the recovery means as described above. This gas hydrate generation condition differs depending on the components contained in the raw material gas.
FIG. 8 shows production equilibrium lines of each component of the raw material gas, that is, methane as the main component and ethane, propane, and i-butane as the subcomponents. The region above these generation equilibrium lines, that is, the region shaded in the figure, is the region where the gas hydrate can be generated in each component. The temperature / pressure condition in this region is the gas hydrate generation condition. In practice, almost all of the components in the raw material gas after the acid gas has been removed are methane, so it is preferable to set the inside of the production container 10a under the gas hydrate production conditions of methane. .

The water drop generating device 12a has a water drop w in the gas phase G.
It is a device for dripping d, and is provided with a water storage part R for storing water therein and a pressurization / depressurizer (pressurization / depressurization means) 14 provided in the water storage part R. The water storage part R is formed by partitioning the top side of the container body 11 with a perforated plate 13. That is,
The perforated plate 13 constitutes the bottom of the water reservoir R, and the water reservoir R
The area when viewed in plan is substantially equal to the flat area inside the container body 11. A large number of holes h are formed in the perforated plate 13, so that the water stored in the water reservoir R can be dripped as water droplets wd over almost the entire region in the gas phase G. There is. In the water storage section R, when the gas hydrate production apparatus C is in operation,
It is always filled with supercooled water. The "supercooling" referred to here means the temperature in the region on the left side of each production equilibrium line shown in FIG. That is, under the same pressure condition, the lower the temperature is, the higher the generation rate of the gas hydrate GH is. Therefore, when water is supercooled in advance and dropped into the gas phase G as water droplets wd, The gas hydrate GH is in a state where it is more easily generated.

In the water storage section R, a pressurizing / depressurizing device (pressurizing / pressurizing means) is provided.
14 are provided. The pressurizer / depressurizer 14 is made of a piezoelectric material such as piezoelectric ceramics, and is connected to an AC power supply and a control means (not shown). That is, the piezoelectric material changes its shape in a cycle corresponding to its frequency when an alternating current of about several tens Hz is applied, so that the water in the water reservoir R is cyclically pressurized and depressurized. It has become. If the water in the water reservoir R is in this state, the holes h formed in the perforated plate 13
Therefore, it becomes a shower and flows into the gas phase G in a substantially vertical direction. However, the pressurizing / depressurizing device 14 periodically pressurizes and depressurizes the water in the water storage portion R to periodically drop a number of substantially spherical water droplets wd having a substantially uniform diameter in a substantially vertical direction. Can be made. The pressurizer / depressurizer 14 is provided with a weighing scale 51 provided in a hydrate storage tank 50, which will be described later, via a control means (not shown).
Connected with. That is, the operation is controlled by the amount of gas hydrate stored in the hydrate storage tank 50.

In the production container 10a, a pumping pipe (water supply means) 25 that connects the bottom side of the container body 11 and the water storage part R to each other.
Is provided so that the water in the water phase W can be supplied to the water storage section R. A pumping pump 26 and a water cooler 27 are provided in the middle of the pumping pipe 25, and the water in the water phase W is generated by the pumping pump 26 in the production container 1.
The water is extracted from the bottom side of No. 1 and is supercooled by the water cooler 27, and is supplied to the water storage section R. In addition, in the vicinity of the mounting position of the pumping pipeline 25 in the generation container 10a, the water phase W
The baffle plate 17 is provided so that the bubbles b therein are not sucked toward the pumping pipe line 25 side.

The gas introducing conduit 21 is branched into a lower conduit (second gas introducing means) 21a and an upper conduit (gas introducing means) 21b in the middle of the conduit, and the lower conduit 21a is The upper pipe lines 21b are connected to the bottom of the container body 11 and to the sides of the container body 11, respectively. That is, the raw material gas is introduced into the water phase W in the container body 11 by the lower pipeline 21a and the upper gas phase G by the upper pipeline 21b. A control valve 22a is provided in the middle of the lower pipeline 21a, and a control valve 22b is provided in the middle of the upper pipeline 21b.
Are provided respectively. These control valves 22a, 22b
Are connected to respective control means (not shown), and the opening degree thereof is controlled by the control means according to the gas hydrate generation condition in the generation container 10a or other conditions, and the inside of the water phase W and the gas phase G are controlled. The amount of raw material gas introduced into the inside can be changed. A dispersion plate 16 is provided at the bottom of the container body 11 so that the raw material gas introduced into the water phase W can be uniformly dispersed in the water phase W as bubbles b. .

The water introduction pipe line 23 is connected to the vicinity of the bottom of the container body 11, and a water phase W is supplied from a water storage tank (not shown).
It supplies water inside. A control valve 24 is provided in the middle of the water introducing pipe 23 so that the amount of water supplied into the water phase W can be changed. The control valve 24 is connected to a control means (not shown) so that the height of the water surface S of the water phase W is always equal to the height of the connection position of the hydrate extraction conduit 31. The amount of water supplied into the phase W can be automatically controlled.

The hydrate extraction conduit 31 discharges the gas hydrate GH floating on the water surface S to the outside of the production container 10a, and the other end thereof is connected to the dehydrator D. A payout pump 32 is provided in the middle of the hydrate extraction conduit 31, and sends the gas hydrate GH in the form of a slurry together with the water near the water surface S to the dehydrator D. In the dehydrator D, the water produced by dehydrating the slurry gas hydrate GH can be recovered, returned to the water introducing pipe 23, and reused for the production of the gas hydrate GH. ing.

The dehydrator D is a hydrate storage tank 5
It is connected to 0. This hydrate storage tank 50
The hydrate storage tank 50 is a tank for temporarily storing the dehydrated gas hydrate GH,
The gas hydrate GH once stored here is sequentially sent to the hydration dehydrator E shown in FIG. The hydrate storage tank 50 is provided with a weighing scale 51 for measuring the weight of the stored gas hydrate GH, and is connected to the pressurizing / depressurizing device 14 of the water droplet generator 12a.

In this gas hydrate production apparatus C, the raw material gas introduced into the water phase W from the lower pipe line 21a of the gas introduction pipe line 21 becomes bubbles b while rising toward the water surface S. Then, a hydration reaction occurs at the gas-liquid interface between the bubble b and water, and a gas hydrate GH is generated. And
Since the water phase W and the gas phase G are in gas-liquid contact on the water surface S, the gas hydrate GH is also formed here. Furthermore, the water droplet wd generated by the water droplet generation device 12a
Immediately after being dripped from the hole h, it has a substantially spherical shape and drops in the gas phase G while maintaining this shape, during which it comes into contact with the gas in the gas phase G and the gas drops wd are gas. The hydrate GH is generated.

As described above, the gas hydrate GH is produced at each of the three locations in the water phase W, the water surface S, and the gas phase G. Since the gas hydrate GH has a lower specific gravity than water, the gas hydrate GH floats on the water surface S. The gas hydrate GH floating on the water surface S is hydrate extraction line 3
It is extracted together with water by 1 and sent to the dehydrator D to reduce the water content. The gas hydrate GH dehydrated by the dehydrator D is stored in the hydrate storage tank 5
It is temporarily stored at 0. This hydrate storage tank 50
The amount of gas hydrate stored inside is 51
And the operation of the water droplet generator 12a is controlled by the measurement result. That is, if the storage amount is small, the frequency of the alternating current applied to the pressure regulator 14 is increased so that a large amount of gas hydrate GH is generated, and if the storage amount is large, the frequency is decreased to decrease the gas hydrate GH. Try to suppress the amount produced.

In the production container 10a according to the present embodiment and the gas hydrate production apparatus C using the same, a water reservoir R having a bottom portion having a large number of holes h formed therein and storing water therein, and a water reservoir R. A water drop generator 12a which is provided inside the water reservoir R and pressurizes and depressurizes the water in a predetermined cycle at a predetermined cycle, and a water drop generator 12a that generates water drops wd and drops the gas into the gas phase G I am preparing for the side. for that reason,
The water in the water reservoir R is made to correspond to the cycle of the pressurizer / depressurizer 14, and the water droplets wd having a substantially constant size, that is, a size capable of effectively generating the gas hydrate GH, are regularly formed in the holes h. Can be dropped into the gas phase G. As a result, the gas hydrate GH can be stably and continuously generated, and the generation rate can be improved.

Further, since the water droplet wd can be dropped over almost the entire region of the gas phase G, the gas hydrate GH can be generated in almost all the region of the gas phase G, and the generation container 10a. Inside gas hydrate GH
Can be effectively used for the production of gas hydrate, and the production efficiency of gas hydrate GH can be increased.

Furthermore, since the water droplet wd can be dropped in a substantially vertical direction, the water droplet wd is stably contacted with and does not collide with the inner wall surface of the container body 11.
The inside of 1 can be dropped. Therefore, the gas hydrate GH is generated in almost all of the water droplets wd dropped in the gas phase G.
Can be generated, the water droplets wd can be effectively used for generation of the gas hydrate GH, and the production efficiency of the gas hydrate GH can be increased.

Furthermore, since the pressurizer / depressurizer 14 is made of a piezoelectric material, the frequency of the applied alternating current is
The shape can be changed with extremely high response characteristics.
Therefore, it is possible to accurately pressurize and depressurize the water in the water reservoir R in a stable cycle, accurately generate water droplets wd of a predetermined size in a stable cycle, and to generate the gas hydrate G.
The H generation rate can be maintained constant, and
Manufacturing efficiency can be improved.

Furthermore, the water phase W and the gas phase G are stored in the production container 10a.
And the raw material gas is introduced into the water phase W as bubbles b. Therefore, water phase W and gas phase G
The gas hydrate GH can be generated also in the water surface S which is a gas-liquid contact portion with and in the water phase W.
That is, since the gas hydrate GH can be generated at three points such as the gas phase G, the water surface S, and the water phase W, the inside of the generation container 10a can be effectively used for generation of the gas hydrate GH. It is possible to further improve the manufacturing efficiency.

[Second Embodiment] A second embodiment of the present invention will be described with reference to FIG. In addition, in this embodiment, the configuration of the production container is only changed as compared with the first embodiment. Therefore, the same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 2, the production container 10b includes a container main body 11, a water drop producing device 12a provided on the upper top side in the container main body 11, and a cooling provided on the outer peripheral portion of the container main body 11. A device (cooling means) 18 is provided.

The cooling device 18 is provided on the outer peripheral portion of the container body 11, and the water droplet generating device 12a in the container body 11 is provided.
The lower side, that is, the gas phase G is cooled. The cooling device 18 may be a so-called cooling jacket that feeds the refrigerant into a jacket provided outside the container body 11, or may have another structure.

In the production container 10b according to the present embodiment and the gas hydrate production apparatus C using the production vessel 10b, the cooling device 18 for cooling the gas phase G is provided. The heat of hydration generated when the gas in the gas phase G hydrates can be effectively removed, and the production of the gas hydrate GH in the gas phase G can be promoted to produce the gas hydrate GH. The efficiency can be further increased.

[Third Embodiment] A third embodiment of the present invention will be described with reference to FIG. In the present embodiment, the configuration of the water droplet generation device of the generation container is only changed as compared with the second embodiment. Therefore, the same components as those in the second embodiment will be designated by the same reference numerals, detailed description thereof will be omitted, and only the vicinity of the water droplet generation device will be illustrated.

As shown in FIG. 3, the production container 10c includes a container main body 11, a water drop producing device 12b provided on the upper top side in the container main body 11, and a cooling provided on the outer peripheral portion of the container main body 11. A device (cooling means) 18 is provided. The water drop generating device 12b is a container body 1 with a perforated plate 13b.
The water storage unit R is formed by partitioning the top side of the unit 1 and stores water therein, and a pressurization / decompression device (pressurization / decompression unit) 14 provided in the water storage unit R.

A large number of holes are formed in the perforated plate 13b, and the diameters of these holes are changed between the outer peripheral side and the inner side of the water storage portion R. The outer peripheral side hole is large and the inner side hole is small. I am trying to become. That is, the hole h1 having a diameter of d1 is formed on the inner side, and the hole h2 having a diameter of d2 (> d1) is formed on the outer peripheral side. Water droplets wd1 and wd2 are dropped into the gas phase G through the holes h1 and h2.

Since the diameter of the dropped water droplet is substantially proportional to the diameter of the hole, the diameter of the water droplet wd2 dropped from the outer peripheral side is approximately d, as compared with the diameter of the water droplet wd1 dropped from the inner hole h1.
It is increased by 2 / d1. That is, the water droplet wd2 dropped from the outer peripheral side and the water droplet d1 dropped from the inner side.
The gas hydrate GH is made larger than the above so that a larger amount of gas hydrate GH is generated on the outer peripheral side. The perforated plate 13
b has the same configuration as the porous plate 13 in the second embodiment except that the diameter of the hole is changed.

In the production container 10c, the cooling device 18
Since the gas phase G is cooled from the outer peripheral side by the above, a slight difference may occur in the temperature condition between the outer peripheral side and the inner side in the gas phase G, and there may be a difference in the gas hydrate generation condition. That is, the outer peripheral side of the gas phase G is a region where a higher cooling effect can be expected. Water drop wd2 is water drop w
It is larger than d1, and a larger amount of gas hydrate GH can be generated, but on the other hand, the generated heat of hydration is also larger. Therefore, a large amount of heat of hydration is generated on the outer peripheral side by dropping a water droplet wd2 having a large amount of heat of hydration, and a large amount of heat of hydration is generated on the inner side where a large amount of heat of hydration is not expected to be removed. The water wd1 can be dropped to properly generate the gas hydrate GH under each gas hydrate generation condition.

In the production container 10c and the gas hydrate manufacturing apparatus C using the same according to the present embodiment, a large hole diameter h2 is formed on the outer peripheral side of the water storage part R, and a small hole diameter h1 is formed inside. I am trying to do it. Therefore, in the gas phase G on the outer peripheral side where a higher cooling effect can be expected,
A large water droplet wd2 can be dropped, and a small water droplet wd1 can be dropped on the inside where the temperature of the gas phase G is likely to rise rather than on the outer peripheral side, and the gas hydrate GH can be appropriately added under each gas hydrate generation condition. As a result, it is possible to increase the production amount of the gas hydrate GH and to stably manufacture the gas hydrate.

[Fourth Embodiment] A fourth embodiment of the present invention will be described with reference to FIGS. In the present embodiment, the configuration of the water droplet generation device of the generation container is only changed as compared with the second embodiment. Therefore, the same components as those in the second embodiment are designated by the same reference numerals, detailed description thereof will be omitted, and only the vicinity of the water droplet generation device will be illustrated.

As shown in FIG. 4, the production container 10d includes a container main body 11, a water drop producing device 12c provided on the upper top side in the container main body 11, and a cooling provided on the outer peripheral portion of the container main body 11. A device (cooling means) 18 is provided. The water drop generator 12c is formed by partitioning the top side of the container body 11 with a perforated plate 13 having a large number of holes h formed therein, and an inner water storage portion R1 and an outer water storage portion R2 that store water therein, and an inner water storage portion. A pressure increasing / decreasing machine (pressure increasing / decreasing means) 14a provided in the section R1 and a pressure increasing / decreasing machine (pressure increasing / decreasing means) 14b provided in the outer peripheral water storage section R2 are provided.

The inner water storage portion R1 and the outer water storage portion R2 are
The water storage part R in the second embodiment is divided into an inner side and an outer peripheral side using a partition plate 15. Water is supplied to each of the inner side water storage part R1 and the outer peripheral side water storage part R2 from the pumping pipeline 25, but they form chambers independent of each other. In addition, the inside of the inner water storage section R1 is provided with a pressurization / decompression device 14
A is provided with a pressurizing / depressurizing device 14b in the outer peripheral side water reservoir R2. These pressurization / depressurizers 14a and 14b are
Except for the size and shape, it has the same configuration as the pressurizer / depressurizer 14 in the second embodiment. The pressurization / depressurizers 14a and 14b can be independently controlled. That is, the water in the inner water storage section R1,
Each of the water in the outer peripheral water reservoir R2 is independently pressurized and depressurized,
The water droplets wd can be dropped independently of each other.

Two examples of a method for producing gas hydrate GH using this production container 10d will be shown. First, a first example of the manufacturing method will be described. In the present example, as shown in FIG. 4, the pressurization / depressurizers 14a and 14b have the same cycle, and the phases thereof are shifted from each other. By shifting the phases in this way, it is possible to shift the dropping timing between the water droplet wd dropped from the inner water storage portion R1 and the water droplet wd dropped from the outer water storage portion R2.
That is, first, after the water droplet wd is dropped from the inner water storage portion R1 to almost completely remove the heat of hydration inside the gas phase G, the water droplet wd is dropped from the outer water storage portion R2 so that the outer circumference of the gas phase G is dropped. After almost completely removing the heat of hydration, the operation of dropping the next water droplet wd from the inner water storage portion R1 is repeated.

In the production container 10d, the cooling device 18
Since the gas phase G is cooled from the outer peripheral side by the above, there is a possibility that the cooling effect may differ between the outer peripheral side and the inner side of the gas phase G. For this reason, when all the water droplets wd are dropped all at once, the heat of hydration from the water droplets wd on the outer peripheral side is immediately removed, but the heat of hydration from the water droplets wd on the inner side is not easily removed, and There is a possibility that a difference occurs in the temperature distribution, the temperature inside the gas phase G rises, and a difference occurs in the gas hydrate generation conditions. In this case, it becomes difficult to generate the gas hydrate GH inside. In addition, the gas concentration distribution in the gas phase G may vary. Therefore, the heat of hydration can be alternately removed by shifting the dropping timing of the water droplet wd between the outer peripheral side and the inner side of the gas phase G, and the difference in temperature distribution that may occur between the outer peripheral side and the inner side is suppressed. At the same time, variations in the gas concentration distribution can be suppressed, so that the gas hydrate GH can be appropriately generated on any side.

Next, a second example of the manufacturing method will be described. In this example, as shown in FIG.
The cycle of vibrations of a and 14b is changed so that the cycle of the pressurizer / depressurizer 14b is higher than that of the pressurizer / depressurizer 14a. By changing the cycle in this way, the number of water droplets wd dropped from the outer peripheral side water storage portion R2 per unit time can be made larger than the number of water droplets wd dropped from the inner water storage portion R1. That is, the number density of the water drops wd dropped on the outer peripheral side of the gas phase G can be set higher than the number density of the water drops wd dropped inside.

As described above, in the production container 10d, the cooling device 18 cools the gas phase G from the outer peripheral side, so that the outer peripheral side of the gas phase G has a higher cooling effect than the inner peripheral side. Can be expected. Therefore, the water droplets wd are dropped at a high density on the gas phase G on the outer circumferential side where a higher cooling effect can be expected, and the water drops wd are dropped on the inner side where the temperature of the gas phase G may rise higher than that on the outer circumferential side. If the gas hydrate is dropped, the gas hydrate GH can be appropriately generated under each gas hydrate generation condition, so that the production amount of the gas hydrate GH can be increased.

In the production container 10d and the gas hydrate manufacturing apparatus C using the same according to the present embodiment, the water storage section is divided into the inner water storage section R1 and the outer water storage section R2, and the pressurizing / depressurizing device 14a is used for the inner water storage section. The outer peripheral water storage portion 14b is provided in the outer peripheral water storage portion R2 independently of each other in the portion R1. Therefore, even if there is a difference in the gas hydrate generation condition between the outer peripheral side and the inner side in the gas phase G, the phase or cycle of the dropped water droplet wd is changed to properly generate the gas hydrate under each condition. The drop timing and the number density of the water drops wd can be set so that the water drops wd can be generated. Therefore, the production amount of the gas hydrate GH can be further increased.

[Fifth Embodiment] A fifth embodiment of the present invention will be described with reference to FIG. In addition, in the present embodiment, the configuration of the water droplet generation device of the generation container is only changed as compared with the fourth embodiment. Therefore, the same components as those in the fourth embodiment are designated by the same reference numerals, detailed description thereof will be omitted, and only the vicinity of the water droplet generation device will be illustrated.

As shown in FIG. 6, the production container 10e includes a container main body 11, a water drop producing device 12d provided on the upper top side in the container main body 11, and a cooling provided on the outer peripheral portion of the container main body 11. A device (cooling means) 18 is provided. The water droplet generating device 12d is the same as the porous plate 1 in the water droplet generating device 12c of the fourth embodiment.
It is replaced with 3b. The perforated plate 13b is the same constituent element as in the third embodiment. That is, the configuration of the water droplet generation device 12d is the same as that of the water droplet generation device 12c except that the configuration of the perforated plate is different. The water droplet generation device 12d can drop a water droplet wd1 from the inner water storage portion R1 and a water droplet wd2 larger than the water droplet wd1 from the outer water storage portion R2 into the gas phase G independently of each other.

Also in the production container 10e, the cooling device 18
Since the gas phase G is cooled from the outer peripheral side by the above, large water droplets wd2 are dropped at a high density on the gas phase G on the outer peripheral side where a higher cooling effect can be expected. A small water droplet wd1 can be dropped at a low density on the inside where the temperature may rise. For this reason, it is possible to achieve an operation / effect that has both the operation / effect in the third embodiment and the operation / effect in the fourth embodiment. That is, since it is possible to properly generate the gas hydrate GH under the respective gas hydrate generation conditions, and it is possible to generate a larger amount of the gas hydrate GH especially on the outer peripheral side, the gas hydrate GH The production amount can be further increased.

In the second to fifth embodiments, the cooling effect for cooling the gas phase from the outer peripheral side of the container body is used, and the cooling effect on the outer peripheral side of the gas phase is higher than that on the inner side. Although described as a premise, the present invention is not limited to this. For example, when a rod-shaped or plate-shaped cooling means is provided inside the gas phase to further enhance the cooling effect on the inside, the reverse of the case described above, that is, increasing the inner hole diameter, Alternatively, the drop cycle of water drops on the inside may be increased.

[0069]

As described above, in the gas hydrate producing container, the gas hydrate production apparatus and the production method according to the present invention, since the above-mentioned constitution is adopted, the gas hydrate can be stably produced. It is possible to provide a gas hydrate production container, a gas hydrate production apparatus, and a production method capable of producing a large amount at high speed and enhancing the production efficiency of gas hydrate.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of a gas hydrate production container and a gas hydrate production apparatus according to the present invention.

FIG. 2 is a schematic configuration diagram showing a second embodiment of a gas hydrate production container and a gas hydrate production apparatus according to the present invention.

FIG. 3 is a schematic configuration diagram showing a third embodiment of a gas hydrate production container and a gas hydrate production apparatus according to the present invention.

FIG. 4 is a schematic configuration diagram showing a fourth embodiment of a gas hydrate production container and a gas hydrate production apparatus according to the present invention.

FIG. 5 is a schematic configuration diagram showing a fourth embodiment of a gas hydrate production container and a gas hydrate production apparatus according to the present invention.

FIG. 6 is a schematic configuration diagram showing a fifth embodiment of a gas hydrate production container and a gas hydrate production apparatus according to the present invention.

FIG. 7 is a block diagram showing a series of apparatus configurations until natural gas is used as a product gas hydrate.

FIG. 8 is a production equilibrium diagram of gas hydrate.

FIG. 9 is a diagram showing a molecular structure of methane hydrate as an example of gas hydrate.

FIG. 10 is a schematic configuration diagram showing a main part of an example of a conventional gas hydrate production apparatus.

[Explanation of symbols]

C gas hydrate production apparatus 10a, 10b, 10c, 10d, 10e generation container (gas hydrate generation container) 11 container bodies 12a, 12b, 12c, 12d water droplet generation device (water droplet generation means) 13, 13b perforated plate 14, 14a , 14b Pressurizing / depressurizing device (pressurizing / pressurizing means) 15 Partition plate 18 Cooling device (cooling means) 21 Gas introduction conduit (gas introducing means) 21a Lower side conduit (second gas introducing means) 21b Upper side conduit (gas introducing means) ) 23 water introduction pipeline (water introduction means) 25 pumping pipeline (water supply means) 31 hydrate extraction pipeline (extraction means) b air bubbles h, h1, h2 holes wd, wd1, wd2 water drops R water reservoir R1 Inner water reservoir R2 Outer water reservoir GH Gas hydrate G Gas phase W Water phase S Water surface

Front page continuation (51) Int.Cl. ⁷ identification code FI theme code (reference) C07C 7/20 C07C 9/04 9/04 C10L 3/00 A (72) Inventor Shojiro Iwasaki Hyogo Ward, Kobe City, Hyogo Prefecture 1-1-1 Wadazakicho Mitsubishi Heavy Industries, Ltd. Kobe Shipyard F-term (reference) 4G075 AA03 AA23 AA35 AA61 BA10 BB05 BD16 BD27 CA03 CA05 CA65 CA66 DA01 DA02 EA06 EB01 EC06 EC09 FA01 FC20 4H006 AA02 AC90 AD16

Claims (9)

[Claims] 1. A gas hydrate producing container for producing a gas hydrate by hydrating a gas containing a hydrate-forming substance with water, comprising: a container body; and an upper side in the container body. And a water drop generating means for generating water drops and dropping the water into the container body, wherein the water drop generating means has a bottom portion having a large number of holes formed therein, and a water storage portion for storing water therein; A pressurizing and depressurizing means that is provided in the section and pressurizes and depressurizes the water in the water storage section in a predetermined cycle
A gas hydrate production container comprising: 2. The gas hydrate generating container according to claim 1, wherein the pressurizing / depressurizing means is made of a piezoelectric material. 3. The gas hydrate generating container according to claim 1, further comprising cooling means for cooling the lower side of the water droplet generating means from the outer peripheral side of the container body. 4. The gas hydrate production container according to claim 1, wherein the hole diameter of the hole is changed between the outer peripheral side and the inner side of the water storage section. 5. The water storage section is divided into an outer peripheral side and an inner side of the water storage section, and the pressurizing / depressurizing means serves as first and second pressurizing / depressurizing means, respectively. Each of them is independently provided.
4. The gas hydrate production container according to any one of 4. 6. The gas hydrate generating container according to claim 1, water supply means for supplying water to the water storage portion, and gas containing a hydrate-forming substance introduced into the container body. And a gas hydrate forming means for forming a gas phase in the container body, and a discharging means for discharging the generated gas hydrate to the outside of the gas hydrate generating container. apparatus. 7. Water introducing means for introducing water into the container body to form a water phase below the gas phase in the container body, and introducing the gas as bubbles into the water phase. The gas hydrate production apparatus according to claim 6, further comprising: 8. A method for producing gas hydrate using the apparatus for producing gas hydrate according to claim 6 or 7, wherein the first pressurizing and depressurizing means and the second pressurizing and depressurizing means are used. A method for producing gas hydrate, characterized in that the phases of the water are shifted from each other to increase or decrease the pressure of the water in the water storage section. 9. A method for producing gas hydrate using the gas hydrate production apparatus according to claim 6 or 7, wherein the first pressurizing and depressurizing means and the second pressurizing and depressurizing means are used. A method for producing gas hydrate, characterized in that the water in the water storage portion is pressurized and depressurized by changing the cycle of each other.