JP2016087594A - Device for and method of producing block of gas hydrate, and block of gas hydrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the block of gas hydrate easily decomposable and having few risk in occurrence of a phenomenon in which a gas is discharged at once from the inside of massive gas hydrate such as pellet toward outside and thereby, the gas hydrate bursts.SOLUTION: A device for production of a block of gas hydrate comprises: a dehydration molding part 30 dehydrating the slurry S of the gas hydrate which is generated from a raw material gas Gand water W is sent thereto to form a block P of the gas hydrate; a ventilation part 40 feeding a ventilation gas Gventilating the inside of the block P of the gas hydrate to the dehydration molding part 30; and an ice formation part 52 forming an ice 60 on at least the outer surface of the block P of the gas hydrate formed in the dehydration molding part 30.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a gas hydrate lump production apparatus, a lump production method, and a gas hydrate lump.

A gas hydrate is a crystal formed by enclosing another molecule (guest molecule) inside a cage structure (sometimes called clathrate) of a water molecule (host molecule) formed by hydrogen bonding. It is produced by reacting a hydrate-forming substance such as carbon dioxide (carbon dioxide), methane gas, natural gas or the like as the guest molecule with water under a predetermined temperature and pressure at which phase equilibrium is a production condition.
The produced gas hydrate is decomposed by changing one of the temperature and pressure, or both the temperature and pressure, and bringing the phase equilibrium out of the production conditions, and becomes a hydrate-forming substance and water.

  Usually, the reaction between the hydrate-forming substance and water is carried out by a known method such as a bubbling method in which fine bubbles are blown into water or a spraying method in which water is sprayed into a hydrate-forming substance (gas). Hydrate is obtained as a gas hydrate slurry.

When the gas hydrate is stored or transported, the generated gas hydrate slurry is, for example, formed into a disk-shaped, spherical, coin-shaped, rod-shaped or the like (sometimes referred to as a pellet). Compression molding is performed (for example, Patent Document 1).

In addition, gas hydrate is known to have an effect of suppressing decomposition, called a self-preserving effect (self-preservation effect) at a temperature equal to or higher than the equilibrium temperature by covering the surface with ice formed. Yes. Conventionally, the gas hydrate has been formed into the above-described pellets and realized storage and transportation over a long period of time due to the self-preserving effect.

By the way, carbon dioxide hydrate (hereinafter sometimes referred to as CO ₂ hydrate) is mixed with beverages, frozen desserts, etc., and the CO ₂ hydrate decomposes in the mouth, so that a texture like carbonated beverages can be obtained. Attempts to produce food have been made (for example, Patent Document 2).

JP 2012-541 A Japanese Patent No. 4716921

Here, as described above, in the case of the gas hydrate pellets for the purpose of storage and transportation, it is required that the gas hydrate pellets are difficult to be decomposed. Therefore, when the gas contained in the hydrate is regasified, the decomposition is performed. Due to the difficulty, regasification may be difficult.
Further, when the compression-molded pellet is decomposed from the inside, gas may be released from the inside toward the outside, and the pellet may be shattered and decomposed.

As described above, when mixed with beverages, frozen desserts, etc., the CO ₂ hydrate pellets are required to be quickly decomposed. In addition, it is required to suppress the phenomenon that the pellets flip.

  Accordingly, an object of the present invention is to provide a gas hydrate that is easily decomposed and has a low risk of occurrence of a phenomenon in which gas is released from the inside of a massive gas hydrate such as pellets to the outside at once. To provide a lump of rate.

  In view of the above problems, the gas hydrate lump production apparatus according to the first aspect of the present invention is such that a gas hydrate slurry generated from a raw material gas and water is fed, and the slurry is dehydrated, and the gas hydrate is dehydrated. A dehydration molding part that forms a lump of gas, a ventilation part that sends a ventilation gas that ventilates the lump of gas hydrate in the dehydration molding part, and at least a lump of the gas hydrate formed in the dehydration molding part And an ice forming part that forms ice on the outer surface.

  When gas hydrate is produced by reacting the raw material gas and water under predetermined pressure conditions and temperature conditions, a gas hydrate slurry in which the gas hydrate particles are suspended in water is obtained. Usually, when the gas hydrate slurry is dehydrated, it becomes a lump with water remaining between the particles of the gas hydrate [see FIG. 2 (A)].

According to this aspect, the gas hydrate slurry is dehydrated in the dehydration molding unit to form a gas hydrate lump in which the gas hydrate particles are collected, and the gas hydrate lump is formed in the gas hydrate lump by the vent. Can be ventilated by aeration gas. Thus, the water remaining between the gas hydrate grains inside the gas hydrate lump is expelled by the ventilation gas, and a vent hole is formed inside the gas hydrate lump. it can.
In the present specification, “in the lump” or “inside the lump” of the gas hydrate means the inside of the outer periphery forming the appearance of the lump.

  Then, the ice forming portion can form ice on at least the outer surface of the gas hydrate lump having the vents, thereby enhancing the storage stability of the gas hydrate lump. In addition, ice may be formed in a part of the air hole in the mass of the gas hydrate.

  Here, conventionally, dehydrated gas hydrate is formed into pellets or other shaped articles (lumps), and ice is formed on the outer surface of the pellets with water remaining between the gas hydrate grains inside the pellets. It was. At this time, the water between the particles of the gas hydrate is also frozen, so that the gap between the particles of the gas hydrate inside the pellet is filled with ice. As a result, the specific surface area of the gas hydrate was reduced, and decomposition of the pellets was suppressed.

  On the other hand, in this aspect, since the air holes are formed in the gas hydrate lump, the specific surface area of the gas hydrate lump is increased. Therefore, it can be set as the mass of the gas hydrate which is easy to decompose. A gas hydrate lump with a large specific surface area is easier to decompose than a gas hydrate pellet with a small specific surface area in which the gaps between the gas hydrate particles inside are filled with ice. By forming ice on the outer surface, the preservability can be enhanced.

  Further, when the gas hydrate lump has the vent hole, gas generated by decomposition of the gas hydrate inside the gas hydrate lump exits the gas hydrate lump through the vent hole. Therefore, it is possible to suppress the occurrence of a phenomenon in which gas is released all at once from the inside of the gas hydrate lump to the outside, and the gas hydrate lump is repelled.

  A gas hydrate lump production apparatus according to a second aspect of the present invention is the gas hydrate lump production apparatus according to the first aspect, wherein the ventilation gas is hydrated more than the raw material gas under pressure and temperature conditions at which the raw material gas is hydrated. It is a gas that is difficult to rate.

The ventilation hole is secured by the momentum of ventilation, but the ventilation gas may react with water during ventilation to form a gas hydrate. When the gas hydrate is formed in the gas hydrate lump (between the gas hydrate grains), the space as a vent hole becomes narrow.
According to this aspect, since the aeration gas is a gas that is less likely to hydrate than the source gas under pressure and temperature conditions at which the source gas hydrates, the aeration gas in the mass of the gas hydrate The risk of gas hydrate formation can be reduced, and the air holes can be formed more efficiently.

  In the gas hydrate lump production apparatus according to the third aspect of the present invention, in the first aspect or the second aspect, the dehydration molding unit has a gravity filtration dehydration structure or a suction filtration dehydration structure. It is a feature.

  According to this aspect, when dehydrating in the dehydration molding unit, it is possible to reduce the possibility that the pressure between the gas hydrate particles in the gas hydrate lump is compressed. Therefore, the vent hole can be easily formed.

  A gas hydrate lump production apparatus according to a fourth aspect of the present invention is the gas hydrate lump production apparatus according to any one of the first aspect to the third aspect, wherein the dehydration molding unit introduces the slurry into a cylindrical body, An inner cylinder having a plurality of drain holes for discharging the water of the slurry at least on a side wall of the cylinder, and an outer side surrounding the outer side of the inner cylinder and receiving the water discharged from the drain holes of the inner cylinder And a cylindrical body.

  According to this aspect, the dehydration molding unit for dehydrating the gas hydrate slurry to form a mass of gas hydrate can be realized with a simple configuration.

  In the gas hydrate lump manufacturing apparatus according to the fifth aspect of the present invention, in the fourth aspect, the inner cylinder body and the outer cylinder body of the dewatering molding section are such that the side walls of the cylinder bodies are along the direction of gravity. The slurry introduction part is provided above the inner cylinder, and the ventilation part is configured to send the ventilation gas from the upper side to the lower side of the inner cylinder. It is characterized by that.

  In the gas hydrate lump production method according to the sixth aspect of the present invention, a slurry containing gas hydrate particles generated from a raw material gas and water is sent, and the slurry is dehydrated to form a gas hydrate lump. A dehydration molding step for forming the gas hydrate, an aeration step for ventilating the gas hydrate lump with an aeration gas, and an ice formation step for forming ice on at least the outer surface of the gas hydrate lump obtained after the aeration step It is characterized by including these.

According to this aspect, since the gas hydrate lump formed by dehydration is ventilated by the aeration gas, the water remaining between the particles of the gas hydrate forming the gas hydrate lump is aerated. A gas can be expelled to form a space between the grains. This makes it possible to obtain a gas hydrate lump having a vent (space) continuous from the inside to the outside of the gas hydrate lump.
The mass of the gas hydrate having the air holes can be easily decomposed, and the possibility of occurrence of a phenomenon that the gas is released from the inside toward the outside when it is broken can be reduced.
Further, by performing the ice formation step, the outer surface of the lump can be covered with ice, and the storage stability of the lump of gas hydrate having the vents can be enhanced.

  The gas hydrate lump production method according to the seventh aspect of the present invention is characterized in that, in the sixth aspect, the aeration step is performed after the dehydration molding step.

  According to this aspect, by performing the ventilation step after the dehydration molding step, water contained in the gas hydrate lump (between the particles of the gas hydrate) is removed by the ventilation gas, and the ventilation hole Can be formed.

  A gas hydrate lump production method according to an eighth aspect of the present invention is characterized in that, in the sixth aspect, the dehydration molding step and the aeration step are simultaneously performed.

  In this embodiment, while the slurry is fed to dehydrate the gas hydrate, aeration gas is vented into the mass of the gas hydrate formed by the dehydration. This makes it possible to smoothly perform the dehydration by aeration and to effectively vent the aeration gas to the gas hydrate lump.

  The gas hydrate lump according to the ninth aspect of the present invention is a gas hydrate lump whose surface is covered with ice, and has voids between the particles of the gas hydrate inside the gas hydrate lump. It is characterized by being hardened.

According to this aspect, since the gas hydrate lump has internal grains and voids, the gas generated by the decomposition of the internal gas hydrate can pass through the voids to the outside of the mass. it can. Therefore, it is possible to suppress the occurrence of a phenomenon in which gas is released all at once from the inside of the gas hydrate lump to the outside and the gas hydrate lump repels.
Further, since the surface of the gas hydrate lump is covered with ice, the storage stability of the gas hydrate lump is enhanced.

  The mass of gas hydrate according to the tenth aspect of the present invention is a mass of gas hydrate whose surface is covered with ice, and when the mass is placed under the decomposition conditions of the gas hydrate, The high-pressure gas generated by the decomposition of the internal gas hydrate has a hole that can move to the outside at a low pressure.

According to this aspect, the gas hydrate lump has a hole through which the high-pressure gas generated by the decomposition of the gas hydrate inside the lump can move to the outside at a low pressure, so that the high-pressure gas passes through the hole. Can go outside the mass of gas hydrate. Therefore, it is possible to suppress the occurrence of a phenomenon in which gas is released at a stretch from the inside of the lump to the outside and the lump is flipped.
Further, since the surface of the gas hydrate lump is covered with ice, the storage stability of the gas hydrate lump is enhanced.

  A gas hydrate lump according to an eleventh aspect of the present invention is the ninth aspect or the tenth aspect, wherein the gas hydrate feed gas is hydrated into the lump inside the lump. In the above, a gas that is more difficult to hydrate than the raw material gas is included.

Under the pressure and temperature conditions at which the gas hydrate source gas is hydrated, a gas that is less likely to be hydrated than the source gas (hereinafter referred to as a hardly hydrated gas) is in a space inside the mass (for example, It is possible to exist in the voids between the gas hydrate grains and the pores connected from the inside to the outside of the lump.
According to this aspect, the presence of the “hardly hydrated gas” in the space inside the lump reduces the possibility that gas hydrate is formed in the space inside the lump and the space is narrowed. be able to. Thus, a space inside the mass can be secured.

The schematic block diagram which shows an example of the lump manufacturing apparatus of the gas hydrate which concerns on this invention. (A) is sectional drawing which shows the mass of the gas hydrate before a ventilation process, (B) is sectional drawing which shows the mass of the gas hydrate after an aeration process. Sectional drawing which shows the lump of gas hydrate after an ice formation process. The figure which shows the other example of a ventilation part.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example, this invention is not limited to these Examples.

<Raw gas>
Examples of the raw material gas to be hydrated in the gas hydrate lump production apparatus according to the present invention include carbon dioxide (hereinafter sometimes referred to as CO ₂ ), methane, ethane, propane, n-butane, and i-butane. , Pentane, or a mixed gas thereof (for example, natural gas). In the following examples, the case where carbon dioxide is used as the source gas will be described.

<Water (raw water)>
Tap water can be used as the water W (raw water) forming the hydrate. Moreover, pure water or purified water can also be used. Moreover, you may add the decomposition inhibitor which suppresses decomposition | disassembly of the produced | generated hydrate in raw material water. As the decomposition inhibiting substance, an electrolyte that generates ions that dissociate in water and have a decomposition inhibiting action can be used.
When the formed gas hydrate lump is used for food, it is desirable to use a substance that has little influence on the human body, such as sodium chloride (NaCl), as the decomposition inhibiting substance.

[Example 1]
A schematic configuration of a gas hydrate lump production apparatus will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an example of a gas hydrate lump production apparatus according to the present invention. 2A is a cross-sectional view showing a gas hydrate lump before the ventilation step, and FIG. 2B is a cross-sectional view showing a gas hydrate lump after the aeration step. FIG. 3 is a cross-sectional view showing a mass of gas hydrate after the ice formation step. FIG. 4 is a diagram illustrating another example of the ventilation portion.

The gas hydrate lump production apparatus 10 in FIG. 1 (hereinafter sometimes simply referred to as the lump production apparatus 10) reacts CO ₂ as the raw material gas G ₀ with water W to generate gas hydrate. A hydrate generation unit 12 that performs a gas hydrate generation step is provided. On the upstream side of the gas hydrate generator 12, a compressor 14 such as a centrifugal compressor and a cooler 16 that convert CO ₂ (raw material gas G ₀ ) to a predetermined pressure and temperature at which CO ₂ is hydrated are provided. I have. For example, CO ₂ can be hydrated under conditions of 1.2 to 4.5 MPa and 0 to 10 ° C.
The hydrate generator 12 is configured such that water W is sent from the line 24 by a pump (not shown) or the like.

  The gas hydrate production process in the hydrate production | generation part 12 can be performed by well-known methods, such as the bubbling method which blows a fine bubble in water, and the spraying method which sprays water in gas. In particular, the bubbling method is preferable because the gas-liquid contact efficiency is good and the target gas hydrate can be efficiently produced.

In the hydrate generation unit 12, a part of the water W is extracted, and the hydrate generation heat is removed by the circulation line 18 via the heat exchanger 20 and returned to the hydrate generation unit 12. Has been. The generated CO ₂ gas hydrate is configured to be sent to the dehydration molding unit 30 through a line 22 as a slurry S in which particles of CO ₂ gas hydrate are suspended. In addition, in the slurry S, the gas hydrate content is about 10 wt% to 20 wt%.

The dehydration molding unit 30 is constituted by an inner cylinder 32 and an outer cylinder 34. As shown in FIG. 1, the side walls of the inner cylinder 32 and the outer cylinder 34 are arranged along the direction of gravity. Yes.
Slurry S is introduced into the inner cylinder 32 from a slurry introduction part 36 provided on the upper part thereof. The inner cylinder 32 has a plurality of drain holes 38 for discharging the water of the slurry on at least the side wall of the cylinder.

The outer cylinder 34 surrounds the outer side of the inner cylinder 32 and is configured to receive the water W ₁ discharged from the drain hole 38 of the inner cylinder 32.
The water W ₁ can be extracted from the lower portion of the outer cylindrical body 34 through the line 26, and can be combined with the water W in the line 24 and returned to the hydrate generator 12.

  In the present embodiment, the dehydration molding unit 30 performs dehydration by gravity filtration. Slurry S is introduced into the inner cylinder 32, water is discharged from the drain hole 38, gas hydrate particles accumulate in the inner cylinder 32, and the particles gather together to form a lump by gravity, and the gas hydrate lump. P is formed.

Further dewatering molding section 30 is provided with a vent 40 which sends a ventilation gas G ₁ bubbling through the mass P of the gas hydrate. Vent 40 is constructed from above of the inner cylindrical member 32 so as to send the vent gas G ₁ downward. In the present embodiment, the ventilation portion 40 has a double tube structure with a slurry introduction portion 36 inside, and is configured to send aeration gas G ₁ from a tube outside the slurry introduction portion 36.

Further, it is desirable to provide a control unit 42 for controlling the supply of insufflation gas G ₁ from the vent 40. Reference numeral 44 is a valve for opening and closing the supply line 46 for supplying breathable gas G ₁ to the vent 40. The controller 42 can control the supply amount, supply timing, pressure, and the like of the aeration gas.
It should be noted that the effect of venting the vent gas G ₁ from the ventilation unit 40 will be described in detail in the description of the mass production method for a gas hydrate with mass production apparatus 10 to be described later.

An ice forming unit 52 is provided on the downstream side of the dewatering molding unit 30. Ice formation unit 52 forms the ice 60 at least on the outer surface of the mass P of gas hydrate ventilation is performed is formed in the dehydration molding unit 30 by insufflation gas G ₁ (FIG. 3). The ice forming unit 52 includes a cooling unit 54 and a pressure reducing unit 56 capable of depressurizing the inside of the ice forming unit 52 from a pressure at which CO ₂ gas hydrate is generated to a pressure at which the CO ₂ gas hydrate is decomposed. .

Next, a gas hydrate lump production method using the lump production apparatus 10 will be described, and the operational effects of the lump production apparatus 10 will be described.
As described above, in the hydrate generator 12, the gas hydrate that generates CO ₂ gas hydrate by reacting CO ₂ as the raw material gas G ₀ with water W under predetermined pressure conditions and temperature conditions. A generation process is performed.

The slurry S containing the CO ₂ gas hydrate particles generated in the gas hydrate generation step is sent to the dehydration molding unit 30 to perform the dehydration molding step. The slurry S is dehydrated in the dehydration molding unit 30 to form a gas hydrate lump P in which the particles of the gas hydrate GH are collected. The gas hydrate content of the gas hydrate lump P is preferably 30 wt% to 60 wt%, more preferably 40 wt% to 50 wt%.
The gas hydrate lump P formed by dehydrating the slurry S is in a state in which water W ₂ remains between the particles of the gas hydrate GH as shown in FIG.

Subsequently, the gas hydrate lump P formed by collecting the gas hydrate GH particles is passed through the gas hydrate lump P (between the gas hydrate GH particles) by the vent 40. with aeration step of venting at the vent gas G _1. Thereby, the water W ₂ remaining between the particles of the gas hydrate GH in the gas hydrate lump P is expelled by the aeration gas G ₁ , and as shown in FIG. Vent holes 50 formed by the gaps between the grains of the mass P can be made.

The ventilation gas G ₁ is preferably a gas that is less likely to be hydrated than the source gas G ₀ under pressure and temperature conditions at which the source gas G ₀ (CO ₂ in this embodiment) is hydrated. Eg, _{N 2} or air, and the like.

Using the same gas as the raw material gas G ₀ as a vent gas G _1, may form a gas hydrate by reacting vent gas G ₁ is the water in the vent. When the gas hydrate is formed in the mass P of the gas hydrate (between the particles of the gas hydrate GH), the space as the vent hole 50 becomes narrow. If the vent gas G ₁ is hydrate of hard gas, can be performed to reduce the possibility of hydrate of vent gas G ₁ in in a mass P of the gas hydrate, more efficiently to the formation of vent holes 50 .
Incidentally, adjusting the amount of ventilation gas G ₁ (e.g., such as increasing the aeration rate) by, water during the grains and grain can be removed the water before hydrate of. Therefore, it is also possible to use the same gas as the raw material gas G ₀ as a vent gas G _1.

  After the dehydration molding step and the aeration step in the dehydration molding unit 30, the gas hydrate lump P is taken out from the bottom 48 of the dehydration molding unit 30 and sent to the ice formation unit 52. In the ice forming section 52, an ice forming step is performed for forming ice 60 (FIG. 3) on at least the outer surface of the gas hydrate lump P.

In the ice formation part 52, the mass P of the gas hydrate after the aeration process is cooled to 0 ° C. or lower (for example, −5 ° C. to −20 ° C.). Further, the inside of the ice forming unit 52 is depressurized by the depressurizing unit 56 to a pressure outside the CO ₂ hydrate generation pressure. Due to this decompression, the gas hydrate on the surface of the gas hydrate lump P is decomposed to generate decomposed water, and the decomposed water freezes. As shown in FIG. 3, the ice 60 covers the surface of the gas hydrate lump P as shown in FIG. Can be formed. As a result, a self-preserving effect is produced in the gas hydrate lump P, and the preservability can be enhanced. It should be noted that ice on which the decomposed water has been frozen may be formed on the surface of the vent 50 in the mass P of the gas hydrate.

Usually, when producing a gas hydrate lump P suitable for long-term storage, water W ₂ remains between the particles of the gas hydrate GH in the gas hydrate lump P (FIG. 2A). ), Ice 60 was formed on the outer surface. In this case, since the water W ₂ between the particles of the gas hydrate GH is also frozen, the gap between the particles of the gas hydrate GH in the gas hydrate lump P is ice in which the water W ₂ is frozen. It will be filled with. As a result, the specific surface area of the gas hydrate lump P was reduced, and its decomposition was suppressed.

  On the other hand, in this embodiment, since the air holes 50 are formed in the gas hydrate lump P, the specific surface area of the gas hydrate lump P is increased. Thus, the gas hydrate lump P can be easily decomposed. The gas hydrate lump P having a large specific surface area is easily decomposed as compared with the gas hydrate pellet having a small specific surface area in which the gap between the particles of the gas hydrate GH inside is filled with ice. By forming the ice 60 on the outer surface of the lump P, its preservability can be enhanced.

In addition, since the gas hydrate lump P has a vent hole 50 that extends from the inside to the outside, gas generated by decomposition of the gas hydrate from the inside of the gas hydrate lump P passes through the vent hole 50. You can get out of the mass P of the gas hydrate. Therefore, it is possible to suppress the occurrence of a phenomenon in which the CO ₂ gas is released all at once from the inside of the gas hydrate lump P to the outside and the gas hydrate lump P is repelled.

In addition to the case where the aeration process is performed after the dehydration molding process as described above, the gas hydrate slurry S is dehydrated to form the gas hydrate lump P, and the aerated gas is contained in the gas hydrate lump P. the G ₁ may be vented. That is, the dehydration molding process and the ventilation process may be performed simultaneously. This fact, together with the smoothly dehydration by ventilation, it is possible to vent the effective venting gas G ₁ with respect to mass P of the gas hydrate.

  When the gas hydrate lump P formed in the dewatering molding unit 30 is large, the ice forming step may be performed in the ice forming unit 52 after being crushed to a desired size. Further, the gas hydrate lump P after the ice formation step may be crushed, and the ice formation step may be performed on the surface exposed by the crushed.

  In this embodiment, the case where dehydration by gravity filtration is performed in the dehydration molding unit 30 has been described. For example, as shown in FIG. 1, a pump 58 for reducing the pressure of the dehydration molding unit 30 is provided, and dehydration by suction filtration is performed. It is also possible to do this.

Further, vent 40 in this embodiment, although the upper inner cylindrical body 32 downward and to send the vent gas G _1, for example, as shown in FIG. 4, a plurality on an outer periphery of the tube of provided in the center of the inner cylindrical body 32 to the vent tube 62 having gas supply holes may be configured out toward the outside (toward the side wall) from the center of the vent gas G ₁ is the inner cylindrical body 32.

The gas hydrate lump P produced by the gas hydrate lump production method using the gas hydrate lump production apparatus 10 described above has the following characteristics.
That is, the mass P of the gas hydrate is covered with ice 60 and is solidified with voids as air holes 50 between the particles of the gas hydrate GH inside the gas hydrate lump P. .

  In other words, the mass P of the gas hydrate is covered with ice 60, and the gas hydrate GH inside the mass P is decomposed when placed under the decomposition conditions of the gas hydrate GH. Has a hole (vent hole 50) through which the high pressure gas generated by the above can move to the outside of the low pressure.

  Since the gas hydrate lump P according to the present invention has air holes 50 in the inner grains, the gas generated by the decomposition of the internal gas hydrate GH passes through the air holes 50 to form the lump. You can go outside. Therefore, it is possible to suppress the occurrence of a phenomenon in which the gas hydrate lump P is repelled by the gas being discharged from the inside of the gas hydrate lump P to the outside at once. Further, the surface of the gas hydrate lump P is covered with ice 60, so that the storage stability is enhanced.

As the ventilation gas G _1, the pressure and temperature conditions to hydrate of _(CO 2 in this _embodiment) source gas G _0, hydrate of hard gases from the raw material gas G ₀ (flame hydrate gases) Is used, the gas hydrate lump P contains the hardly hydrated gas.
Accordingly, the hardly hydrated gas can be present in the vent hole 50 inside the lump P, and a gas hydrate can be formed in the vent hole 50 to reduce the possibility that the vent hole 50 is narrowed. Thus, a space in the vent hole 50 can be secured.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the invention described in the claims, and it goes without saying that these are also included in the scope of the present invention. .

10 gas hydrate lump production apparatus, 12 hydrate generation part,
14 compressors, 16 coolers, 18 circulation lines, 20 heat exchangers,
22, 24 lines, 30 dewatering molded parts, 32 inner cylinders, 34 outer cylinders,
36 slurry introduction part, 38 drainage hole, 40 ventilation part,
42 control unit, 44 valve, 46 supply line, 48 bottom,
50 Ventilation hole, 52 Ice formation part, 54 Cooling part, 56 Pressure reducing part, 58 Pump,
60 ice, 62 vents,
G ₀ feed gas, _{G 1} insufflation _{gas, W, W} 1, _{W 2} of water, S slurry

Claims (11)

A slurry of gas hydrate generated from the raw material gas and water is sent, and the slurry is dehydrated to form a dehydrated molding block of gas hydrate,
A ventilation part for sending a ventilation gas to ventilate the mass of the gas hydrate in the dehydration molding part;
An ice forming part that forms ice on at least the outer surface of the mass of the gas hydrate formed in the dewatering molding part,
A gas hydrate lump production apparatus characterized by the above. In the gas hydrate lump production apparatus according to claim 1,
The ventilation gas is a gas that is less likely to hydrate than the source gas under pressure and temperature conditions at which the source gas hydrates.
A gas hydrate lump production apparatus characterized by the above. In the gas hydrate lump production apparatus according to claim 1 or 2,
The dehydration molding unit is a gravity filtration dehydration structure or a suction filtration dehydration structure.
A gas hydrate lump production apparatus characterized by the above. In the gas hydrate lump production apparatus according to any one of claims 1 to 3,
The dehydration molding part is
An inner cylinder having a plurality of drain holes for discharging the water of the slurry on at least a side wall of the cylinder, while the slurry is introduced into the cylinder;
An outer cylinder that surrounds the outside of the inner cylinder and receives water discharged from the drain hole of the inner cylinder,
A gas hydrate lump production apparatus characterized by the above. In the gas hydrate lump production apparatus according to claim 4,
The inner cylinder body and the outer cylinder body of the dehydration molding unit are disposed so that the side wall of each cylinder body is along the direction of gravity, and the slurry introduction section is provided above the inner cylinder body,
The ventilation portion is configured to send the ventilation gas from the upper side to the lower side of the inner cylindrical body,
A gas hydrate lump production apparatus characterized by the above. A slurry containing gas hydrate particles generated from a raw material gas and water is sent, and the slurry is dehydrated to form a mass of gas hydrate;
A ventilation step of ventilating the gas hydrate mass with aeration gas;
An ice formation step of forming ice on at least the outer surface of the mass of the gas hydrate obtained after the aeration step,
A method for producing a mass of gas hydrate. In the gas hydrate lump manufacturing method according to claim 6,
Performing the ventilation step after the dehydration molding step;
A method for producing a mass of gas hydrate. In the gas hydrate lump manufacturing method according to claim 6,
Including simultaneously performing the dehydration molding step and the ventilation step.
A method for producing a mass of gas hydrate. A mass of gas hydrate whose surface is covered with ice,
It is hardened with a gap between the gas hydrate grains inside it,
A mass of gas hydrate characterized by that. A mass of gas hydrate whose surface is covered with ice,
When placed under the decomposition conditions of the gas hydrate, the high-pressure gas generated by the decomposition of the gas hydrate inside the mass has holes that can move to the outside of the low pressure,
A mass of gas hydrate characterized by that. In the mass of gas hydrate according to claim 9 or claim 10,
The gas contains a gas that is less likely to be hydrated than the source gas under the pressure and temperature conditions at which the source gas of the gas hydrate is hydrated inside the mass.
A mass of gas hydrate characterized by that.

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