JP2001342473A - Apparatus for producing gas hydrate and apparatus for dehydrating gas hydrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for dehydrating, cooling and taking out a gas hydrate, capable of efficiently and continuously dehydrating/cooling and solidifying a slurried gas hydrate, hardening the gas hydrate powder into a block state and taking out the blocked material under an atmospheric pressure. SOLUTION: This apparatus for dehydrating, cooling and taking out a gas hydrate by dehydrating and solidifying a slurried gas hydrate and taking out the gas hydrate under an atmospheric pressure is equipped with a taking-out apparatus main body 31 furnished with a feed opening 32 for the slurried gas hydrate on the top of a pressure container, a screw extrusion molding machine 33 furnished with an exhaust port 37 and an outlet closing means arranged on the bottom in the taking-out apparatus main body 31 and a cooling means 41 for cooling the vicinity of an outlet 39 of the screw extrusion molding machine 33.

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 apparatus for producing gas hydrate from a raw material gas such as natural gas and a gas hydrate dehydrating apparatus for dehydrating slurry gas hydrate.

[0002]

2. Description of the Related Art At present, as a method of storing and transporting natural gas mainly composed of hydrocarbons such as methane, natural gas is collected from a gas field, cooled to a liquefaction temperature, and liquefied natural gas (LNG). It is a common practice to store and transport in a state where it is kept. However, for example, in the case of methane, which is a main component of liquefied natural gas, liquefaction requires cryogenic conditions such as -162 ° C. In order to store and transport while maintaining such conditions, a dedicated storage device is required. And dedicated transportation means such as an LNG ship. Since the production, maintenance and management of such devices and the like require extremely high costs, low-cost storage and transportation methods that are alternatives to the above methods have been intensively studied. As a result of these studies, a method has been discovered in which natural gas is hydrated to produce a gas hydrate in the solid state (hereinafter referred to as "gas hydrate") and stored and transported in the solid state. Particularly promising. This method does not require cryogenic conditions as in the case of handling LNG, and is relatively easy to handle because it is solid. For this reason, an existing refrigeration system or a slightly improved version of an existing container ship can be used as a storage device or a transportation means, and therefore, it is expected that the cost can be significantly reduced.

[0003] The gas hydrate is a kind of clathrate compound (clathrate compound). As shown in FIG. 9, a three-dimensional cage-type clathrate formed by a plurality of water molecules (H ₂ O) is used. A crystal structure in which molecules constituting each component of natural gas, that is, methane (CH ₄ ), ethane (C ₂ H ₆ ), propane (C ₃ H ₈ ), etc. are contained in a lattice (clathrate) and are included. It is what makes. The intermolecular distance between the natural gas constituent molecules included in the clathrate is shorter than the intermolecular distance in the gas cylinder when natural gas is charged at a high pressure. This means that natural gas can produce tightly packed solids, for example under conditions where methane hydrate can be stably present, ie at -30 ° C. and atmospheric pressure (1 kg / cm ² A). The volume can be reduced to about 1/190 compared to the gas state. As described above, gas hydrate can be obtained at a relatively easy temperature and temperature.
It can be manufactured under pressure conditions and can be stably stored.

In this method, natural gas after being received from a gas field is subjected to an acid gas removal step in which an acid gas such as carbon dioxide (CO ₂ ) or hydrogen sulfide (H ₂ S) is removed. It is stored in the gas storage part once under high pressure. This natural gas is then hydrated in a hydrate refining step to form gas hydrate. This gas hydrate is a slurry in which water is mixed, and in the subsequent dehydration step, mixed unreacted water is removed, and further adjusted to a predetermined temperature and pressure through a cooling step and a decompression step. In a state, it is sealed in a container such as a container and stored in a storage device. At the time of transportation, the container is 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 a natural gas state through a hydrate decomposition step and sent to each supply point.

[0005]

However, the above-described conventional processes from gas hydrate generation to transportation have the following problems to be solved. (1) The process of generating gas hydrate is 0 ° C
It is operated in a pressurized state under a nearby plus temperature. However, if the produced gas hydrate is taken out under the atmospheric pressure as it is, it will be decomposed. Therefore, it is necessary to cool the gas hydrate to a low temperature of about −30 ° C. and then take it out to the atmospheric pressure. (2) In the gas hydrate generation plant, the gas hydrate immediately after generation is a slurry containing a large amount of water. Therefore, if the gas hydrate in a slurry state is stored or transported as it is or frozen, the efficiency of storage and transport is reduced by the volume of water (ice), which causes a cost increase. Therefore, it is desired to dewater the slurry gas hydrate at low cost.

(3) Excess moisture contained in the slurry gas hydrate undergoes a phase transformation to ice at 0 ° C. or lower and adheres to the gas hydrate. For this reason, the low-temperature cooling for suppressing the decomposition described in (1) needs to be performed after the slurry gas hydrate is dehydrated. (4) In the mass production process, it is necessary to reduce the production cost of gas hydrate. For this reason, it is desired to reduce as much as possible large-capacity structures such as intermediate storage tanks that require high costs for construction and the like.

[0007] The present invention has been made in view of the above-mentioned problems of the prior art, and efficiently and continuously dehydrates and cools the produced slurry gas hydrate to solidify the gas hydrate. The purpose is to improve the production efficiency of gas hydrate and reduce various costs by solidifying the powder in a block shape and taking it out to the atmosphere.

[0008]

The present invention employs the following means in order to solve the above-mentioned problems. The gas hydrate production apparatus according to claim 1 includes a gas hydrate generation reactor that generates a slurry gas hydrate from a raw material gas, and a gas hydrate dehydration apparatus that dehydrates the generated slurry gas hydrate. A gas hydrate producing device comprising: a gas hydrate dehydrating device, wherein the gas hydrate dehydrating device physically dehydrates the generated slurry-like gas hydrate; and A hydration / dehydration means for reacting water contained in the hydrate with a raw material gas to form a hydrate is provided.

A gas hydrate dehydrator according to a second aspect of the present invention is a gas hydrate dehydrator for dehydrating and solidifying a slurry-like gas hydrate supplied from a gas hydrate production reactor and removing the gas hydrate under atmospheric pressure. An extraction device main body provided with a slurry gas hydrate supply port at an upper part of the container, a screw dewatering consolidation molding device provided at a lower portion in the extraction device main body and having a drain port and an outlet sealing means, And cooling means for cooling the vicinity of the outlet of the molding means. In addition, a single-screw or twin-screw extruder can be used as the above-mentioned screw dewatering consolidation means.

According to such a gas hydrate dewatering device, the slurry gas hydrate supplied into the take-out device main body is continuously dewatered / consolidated / formed by passing through the screw dewatering / consolidating means, Furthermore, since the material cooled by the cooling means near the outlet is continuously taken out to the atmosphere, large-capacity structures such as intermediate storage tanks in the manufacturing plant can be reduced.

According to a third aspect of the present invention, there is provided the gas hydrate dehydrator according to the second aspect, wherein the raw material gas for forming the gas hydrate is supplied to the screw dehydration consolidation means of the unloading device main body. A gas supply pipe for supplying gas is provided.

According to such a gas hydrate dehydrating apparatus, a large amount of water contained in the slurry gas hydrate reacts with the gas hydrate forming substance supplied from the pressurized gas introducing pipe, so that the inside of the main body of the extracting apparatus is removed. It is possible to additionally generate gas hydrate in the above.

According to a fourth aspect of the present invention, there is provided the gas hydrate dewatering apparatus, wherein a cutting means for cutting the gas hydrate molded body to a predetermined length is provided at an outlet of the screw dewatering compacting means. is there. In this case, it is preferable that the outlet of the screw dewatering consolidation means is formed in a rectangular cross section.

According to such a gas hydrate dewatering apparatus, a gas hydrate molded body which is dewatered, consolidated, molded and cooled and continuously taken out by the screw dewatering and compacting means can be cut into a desired length. Space efficiency of storage and transportation can be improved. In this case, in particular, if the outlet portion has a rectangular cross-sectional shape, it can be stored and transported in a cubic or rectangular parallelepiped block shape, so that the space efficiency can be further improved.

The gas hydrate dehydrating apparatus according to a sixth aspect of the present invention is characterized in that a dehydrating means for dehydrating excess water from the introduced slurry gas hydrate is provided below the supply port. In this case, it is preferable that the dewatering unit includes one or both of a dewatering screen and a mechanical dewatering device for mechanically dewatering. Preferably, the mechanical dehydrator is a press dehydrator, and more preferably, the press dehydrator is arranged in a plurality of rows in the vertical direction. When such a press dewatering machine is used, a weir plate is provided opposite to both side surfaces of the press dewatering machine, and almost the center of the upper end of the weir plate located above the roller surface is cut out to perform dewatering. It is preferable to provide an overflow channel for draining excess water to the side.

According to such a gas hydrate dehydrator, the first dehydration is performed by the dehydrator and then sent to the screw dehydrating and compacting means, so that the dehydration can be performed efficiently. And, after passing through a dewatering screen as a primary dehydrating means, and then passing through a mechanical dehydrating means such as a press dehydrator as a secondary dehydrating means, the dehydrating efficiency can be further improved. In addition, the dewatering efficiency is further increased by arranging the press dehydrator in a plurality of stages vertically, and by forming the overflow flow path by providing a weir plate on both sides, the excess water that has been dehydrated with great effort is combined with gas hydrate. Drain without contact.

A gas hydrate dehydrator according to claim 11, which is a gas hydrate dehydrator for dehydrating a gas hydrate in the form of a slurry, comprising: a container having an internal space for accommodating the gas hydrate; Gas supply means for supplying a source gas before being hydrated into a space; cooling means for cooling a gas hydrate contained in the internal space; and contacting the source gas with the gas hydrate in the internal space And stirring means for stirring.

A gas hydrate dehydrator according to a twelfth aspect of the present invention is the gas hydrate dehydrator according to the eleventh aspect, wherein the slurry hydrate before being accommodated in the container is dehydrated under pressure. It is characterized by comprising means.

According to a thirteenth aspect of the present invention, in the gas hydrate dehydrator of the eleventh or twelfth aspect, the stirring means has a spiral ridge on a side surface and is disposed in the internal space. And a plurality of shafts that carry the gas hydrate while rotating individually.

According to a fourteenth aspect of the present invention, there is provided the gas hydrate dehydrator according to the thirteenth aspect, wherein the stirring means includes the two shafts, and the two shafts are arranged in parallel. The projections are arranged so as to overlap each other when viewed from the axial direction.

In such a gas hydrate dehydrating apparatus, when a gas before being hydrated is brought into contact with a slurry-like gas hydrate and cooled while stirring, the gas hydrate is rotated by a plurality of shafts. Moves intricately and constantly renews gas contact surfaces. The gas contacts the renewed contact surface actively and reacts with moisture adhering to the gas hydrate particle surface to hydrate one after another. Thereby, the excess moisture constitutes the hydrate and decreases, while the gas hydrate increases its amount.

According to a fifteenth aspect of the present invention, in the gas hydrate dehydrator according to any one of the eleventh to fourteenth aspects, the reaction state between the gas hydrate and the gas accommodated in the internal space is detected. And a control means for controlling the supply amount of the gas according to the reaction state.

In such a gas hydrate dehydrating apparatus, when the reaction with the water remaining in the gas hydrate progresses and the gas decreases, the gas is replenished. By adjusting the gas supply amount according to the above, the dehydration effect by the hydration reaction is promoted.

A gas hydrate dehydrator according to a sixteenth aspect is the gas hydrate dehydrator according to the fifteenth aspect, wherein the detecting means is disposed in proximity to a gas hydrate inlet provided in the container body. It is characterized by being.

In such a gas hydrate dehydrator, the reaction between the remaining moisture and the gas proceeds more rapidly and vigorously as the pressure is higher. Therefore, by arranging the detecting means on the inlet side where the pressure is relatively low and the reaction hardly occurs, the reaction state inside the container body can be grasped more accurately.

A gas hydrate dehydrator according to a seventeenth aspect is the gas hydrate dehydrator according to any one of the eleventh to sixteenth aspects, wherein the gas hydrate outlet provided in the container body is also provided in the container body. It is characterized in that it is arranged at a lower position than the gas hydrate inlet provided.

In such a gas hydrate dehydrator, when the dehydrated gas hydrate is exposed to be pushed out from the outlet, the gas hydrate is sequentially dropped or slid down by the action of gravity and taken out of the gas hydrate dehydrator. So that it can be easily put into storage facilities.

[0028]

Next, a first embodiment of the present invention will be described with reference to the drawings. In the embodiment described below, an apparatus and a method for consistently producing methane hydrate using a gas hydrate forming substance as methane gas which is a main component of natural gas will be described. Not only
There are also ethane, propane, butane, krypton, xenon and carbon dioxide. The methane hydrate MH
As shown in FIGS. 9A and 9B, a clathrate compound in which methane molecules M are contained in a basket formed by arranging water molecules W in a three-dimensional manner (for example, dodecahedral or tetrahedral) is shown in FIG. (Clathrate), which is generated based on the following reaction formula, for example. Further, when the methane hydrate MH is decomposed, about 0.9 volume of methane hydrate and about 170 methane gas in a standard state are obtained. CH ₄ + 5.7H ₂ O → CH ₄ .5.7H ₂ O + heat of hydration

FIG. 3 is a block diagram showing an embodiment of a gas hydrate producing apparatus in which the gas hydrate dehydrating apparatus of the present invention is incorporated. In FIG. 3, reference numeral 1 in FIG.
Is a closed gas hydrate generation reactor, in which a cooling coil 2 is inserted as a cooling means (temperature control means) in the gas hydrate generation reactor 1 of the pressure vessel. Thereby, the below-mentioned aqueous phase L in the gas hydrate generation reactor 1 can be cooled and maintained at, for example, about 1 ° C. within the gas hydrate generation temperature range (eg, 1 to 5 ° C.). When generating gas hydrate, heat of hydration is generated. On the other hand, since gas hydrate is not generated unless it is in a low-temperature and high-pressure state, the gas hydrate generation reactor 1 is provided with cooling means as described above. It is preferable to always cool. In the illustrated example, the cooling coil 2 is used as the cooling means, but is not limited to this. For example, the gas hydrate production reactor 1 may be surrounded by a cooling jacket, and the cooling jacket may be supplied with brine from a brine tank and circulated, or a radiator may be inserted into the gas hydrate production reactor 1, or These may be used in combination.

Reference numeral 3 denotes a water storage tank. Water is introduced into the gas hydrate generation reaction device 1 from the water storage tank 3 via the pipe 4 to enter the gas hydrate generation reaction vessel 1. An aqueous phase L (liquid phase) can be formed. The pipe 4 is provided with a water supply pump 5 and a valve 6, and is controlled so that the liquid level S of the aqueous phase L is maintained at a constant level. In addition, the water storage tank 3, the pipe 4, and the water supply pump 5
The water supply means WS is constituted by the above.

On the lower side wall of the gas hydrate production reactor 1, a methane inlet 1a is provided. The methane inlet 1a has a gas storage unit 7 as a methane supply source.
And a methane gas (gas hydrate forming substance) is supplied through a pipe 8. The pipe 8 is provided with a normal valve 9 and a flow control valve 10. The degree of opening of the flow control valve 10 is controlled by a pressure gauge 11 that detects the pressure of a gas phase G (methane gas) described later in the gas hydrate generation reactor 1. Thereby, methane is replenished in the gas hydrate generation reaction vessel 1, and the pressure of the gas phase G is constantly increased to the gas hydrate generation pressure (4 in this example).
0 atm). A methane supply means (gas hydrate forming substance supply means) GS is constituted by the gas storage unit 7 and the pipe 8, and the pressure control means PC in the production reactor is controlled by the pressure gauge 11 and the flow rate control valve 10.
Is configured.

Methane (natural gas containing methane as a main component) supplied to the gas storage unit 7 is collected from a gas field 12 and then subjected to an acidic gas removing step 13 to remove acidic gases such as carbon dioxide and hydrogen sulfide. Is done. Thereafter, the temperature is reduced to a low temperature / high pressure via a compressor or the like, and sent to the gas storage unit 7 to be temporarily stored.

At the bottom of the gas hydrate generation reactor 1, there is provided a water outlet 1b for extracting unreacted water, and the unreacted water extracted from the water outlet 1b is supercooled. Then, it is configured to be supplied again into the gas hydrate production reactor 1. More specifically, the water outlet 1b and the spray nozzle 14 provided at the top of the gas hydrate generation reactor 1 are connected by a pipe 15, and the pipe 15 has a valve 16, a water circulation pump 17, a heat exchanger, and the like. (Cooler) 18 and valve 19
Are sequentially arranged. The water extracted by the water circulation pump 17 is supercooled by the heat exchanger 18,
The gas is supplied from the spray nozzle 14 into the gas phase G (methane atmosphere) in the gas hydrate production reactor 1 in the form of a spray (see reference symbol SP).

Here, the supercooling means, as shown in FIG.
At least the temperature is lower than an arbitrary point D on the methane hydrate production equilibrium line C (in the direction of arrow X) or the pressure is higher (in the direction of arrow Y). In addition, the area above the generation equilibrium line C (the area shaded for convenience)
Is a methane hydrate formation region (under methane hydrate formation conditions). For reference, ethane, propane and butane formation equilibrium lines are also shown. Heat exchanger (cooler) 1
For example, a multi-tube heat exchanger excellent in heat conduction efficiency, a coil heat exchanger having a simple structure, and a plate heat exchanger excellent in heat conduction efficiency and easy to maintain can be used as 8. In addition, the water circulation pump 17, the pipe 15,
The heat exchanger 18 and the like constitute a water subcooling circulation unit CW.

Here, the spray nozzle 14 is shown in FIG.
As shown in (a), a gas hydrate generation reactor 1
Water particles SP having an outer diameter of several tens of μm on average (in principle, the smaller the particle diameter, the better) from the nozzle hole 14 a of the spray nozzle 14 toward the gas phase G. Gushing. As described above, the surface area per unit volume of water, that is, the contact area with the gas phase G is extremely increased by spraying water into the gas phase G in a spray form to form a large amount of water particles SP. Can be. As described above, when the unreacted water extracted from the bottom of the gas hydrate generation reactor 1 is sprayed in the gas hydrate generation reactor 1 by the spray nozzle 14,
It is important to prevent clogging of the spray nozzle 14 by foreign matter. Therefore, a filter 16a for collecting foreign matter such as gas hydrate is provided in the pipe 15,
It is preferable to reliably remove foreign matter from the extracted unreacted water. The spray means of FIG. 4B will be described later.

A liquid layer outlet 1c is provided near the liquid surface S of the aqueous phase L in the gas hydrate production reactor 1.
The liquid layer outlet 1c is connected to a gas hydrate dehydrator 30 described later by a pipe 20. The pipe 20 is provided with a valve 21, an extraction pump 22, and the like as necessary. With such a configuration, the relatively low-density methane hydrate layer MH floating on the liquid surface S is sucked by the extraction pump 22 from the liquid layer extraction port 1c, and
The methane hydrate and water are turned into a slurry, and are transferred to the subsequent process through the pipe 20. That is, the slurry-like methane hydrate (slurry gas hydrate) generated by the gas hydrate generation reaction device can be easily supplied to the gas hydrate dehydration device 30 in the subsequent process by flowing the same together with excess water. It is.

Next, the configuration of the gas hydrate dehydrator 30 according to the present invention will be described in detail with reference to FIG. This gas hydrate dehydrator (hereinafter, dehydrator) 30
Is a device for dehydrating and solidifying slurry-like methane hydrate supplied from the above-mentioned gas hydrate production reactor 1, and taking it out under atmospheric pressure. This dehydrator 3
The discharge device main body 31 is a pressure vessel, and has a supply port 32 to which the pipe 20 is connected and for receiving methane hydrate in the form of slurry at the upper part.

A screw extruder 33 is provided in the lower part of the main body 31 of the unloading device as a means for screw dewatering and compacting. The screw extruder 33 drives a screw 34 inside the casing by a motor 35
Has the function of pressure-feeding the slurry-like methane hydrate introduced from the inlet 36 provided upward and having the supply port 32 in the extrusion direction (from left to right in the drawing). are doing. The screw extruder 33 may employ a single screw having a single screw 34 or a screw 34
May be adopted for a plurality of axes having two or more.

A drain 38 provided below the inlet 36 is provided with a screen 38 through which water can easily pass but methane hydrate does not easily pass. A pipe 49 for guiding excess water to the water storage tank 3 is connected to the drain port 37. Further, before reaching the outlet 39, there are provided a consolidation forming part 40 for gradually reducing and reducing the cross-sectional shape of the casing and an outlet sealing means (not shown). As a result, the slurry-like methane hydrate fed under pressure is dewatered and consolidated, is formed into an outlet cross-sectional shape, and is continuously sent out from the outlet 39 to the atmosphere. The outlet sealing means provided here seals the outlet 39, which is an opening of the unloading device main body 31 as a pressure vessel, as necessary. For example, a sealing hatch or the like can be used. In addition, this outlet sealing means is used as the outlet valve of the discharge device main body 31 which is a pressure vessel in which the methane hydrate to be fed is a pressure vessel from the start of the operation of the screw extruder 33 to a steady operation state. It is closed until it performs its function.

A cooling means 41 is provided near the outlet 39 of the screw extruder 33 for the purpose of cooling the dehydrated, compacted and formed methane hydrate. The cooling means 41 is connected to the outlet 39 of the screw extruder 33.
A cooling jacket attached so as to cover the outer periphery of the consolidation molding section 40 and the casing may be used, or a refrigerant may be guided to the outlet 39 side using the shaft of the screw extruder 33 and cooled from the inside. It may be something. Of course, both may be used in combination.
The refrigerant used here can be shared with the cooling means of the gas hydrate generation reactor 1 described above,
Other cold heat existing around the gas hydrate production device such as natural gas may be introduced and used.

The dehydrating device 30 is provided with the above-described take-out device main body 3.
1. If the screw extruder 33 and the cooling means 41 are provided, the methane hydrate in a slurry state is dewatered and compacted by the screw extruder 33, further cooled by the cooling means 41, and the cross-sectional shape of the outlet 39 is obtained. It can be continuously taken out under atmospheric pressure as a methane hydrate compact (gas hydrate compact) having the following formula, that is, as a long compact obtained by compacting methane hydrate powder.

However, in order to further improve the performance of the dewatering device 30, in the example shown in FIG.
2 are connected. The pressurized gas introduction pipe 42 pushes and supplies methane gas, which is a raw material gas necessary for forming methane gas hydrate, into the extraction device main body 31 maintained at a high pressure. When methane hydrate is generated in the dehydrating device 30, gaseous methane becomes solid methane hydrate, and the internal pressure decreases. On the other hand, in order to generate methane hydrate at high speed, the conditions in the dehydrator 30 must be set to a lower temperature and higher pressure. Therefore, in order to eliminate the pressure drop of the dehydrator 30 due to the generation of methane hydrate, the pressure in the dehydrator 30 is continuously detected by the pressure gauge 11A, and based on this, the opening of the flow control valve 10A is determined. Is controlled continuously. Thereby, a required amount of methane gas is replenished in the dehydrating device 30 and the inside of the dehydrating device 30 is maintained at a constant high pressure state, whereby high-speed generation of methane hydrate is achieved. In the dehydrator 30, it is preferable that the screw 34 and the press dehydrator 46 are additionally provided with a cooling means in order to promote the generation of gas hydrate in the main body 31. Further, as the methane gas supplied to the extraction device main body 31, it is preferable to use the methane gas stored in the gas storage unit 7 by guiding it through a pipe or the like.

The outlet 3 of the screw extruder 33
9 is provided with cutting means 43 for cutting a long methane hydrate molded body continuously extruded into the atmosphere to a predetermined length. As the cutting means 43, for example, a cutter or the like that moves up and down along the outlet 39 can be adopted, and it is possible to cut the methane hydrate compact into a length suitable for storage and transport. Considering such storage and transportation,
The cross-sectional shape of the outlet 39 is preferably rectangular rather than circular, elliptical, polygonal, or the like. This is exit 39
Has a rectangular cross section, so that a long rectangular parallelepiped methane hydrate molded body is extruded continuously, and if it is cut into an appropriate length, it becomes a rectangular parallelepiped or cube of an appropriate size, resulting in wasteful space. Because they can be stacked and stored and transported without issuing the wastewater.

In the example shown in the figure, a dewatering screen 44 is provided below the supply port 32 as primary dewatering means in order to efficiently dewater surplus water from slurry-like methane hydrate. For the dewatering screen 44, a mesh member or the like that allows water to easily pass but does not easily pass methane hydrate is used. The slurry-like methane hydrate dropped from the supply port 32 is used for the screw extruder 3.
3 is installed so as to be inclined toward the entrance 36. A drain port 45 is provided below the dewatering screen 44, and a pipe 49 connected to the water storage tank 3 is connected to the drain port 45. As a result, the dewatering screen 44
The slurry-like methane hydrate that has fallen on the upper side passes through a dewatering screen 44 and is separated from excess water.
Methane hydrate and water remaining on the dewatering screen 44 are drained from the inlet 36 from the lower end of the inclined surface.
Fall towards. Therefore, the surplus water is dewatered by an amount that has passed through the dewatering screen 44, and the slurry becomes methane hydrate with reduced excess water.

In the illustrated example, a dewatering screen 44 is further provided.
A press dewatering machine 46 is installed above the inlet 36 as a second dewatering means for dewatering the slurry-like methane hydrate that has fallen from the water. As shown in FIG. 2, the press dewatering machine 46 has a structure in which excess water is dewatered by a compressive force applied when slurry-like methane hydrate passes between a pair of rollers 46a, 46a. Although the three-stage press dewatering machine 46 is disposed in the up-down direction, the number of stages to be installed may be appropriately selected based on various conditions. Further, as shown in FIG. 2, a weir plate 47 is provided opposite to both side surfaces of the press dewatering machine 46, and a V-shaped notch 48 is formed at the upper end of the weir plate 47 located above the upper surface of the roller 46a.
Is provided to form an overflow channel. The notch 48 may be provided by cutting out the center of the weir plate 47 that substantially coincides with the position where the pair of rollers 46a contact. As a result, the dewatered surplus water accumulates on the roller 46a, but is preferentially drained to both sides from the lowest notch 48 in the side weir plate 47, so that the dehydrated methane hydride falling directly below the roller 46a It is possible to prevent the rate and the drainage water from joining again to lower the dewatering efficiency. Excess water drained from the notch 48 is guided to a pipe 49 from a drain port (not shown) provided adjacent to the inlet 36.

In the illustrated example, as a physical dewatering means, a dewatering screen 44 for dewatering by using gravity acting on surplus water, and a three-stage press for mechanically dewatering a gas hydrate containing surplus water. Although the dewatering machine 46 is provided in parallel, depending on the conditions, only one of the dewatering screen 44 and the press dewatering machine 46 may be provided. Further, as a mechanical dehydrator that replaces the press dehydrator 46,
For example, a centrifugal dehydrator may be used.

Next, the operation of the above-described gas hydrate manufacturing apparatus, that is, the manufacturing method will be described. The air in the gas hydrate generation reactor 1 is replaced with methane gas in advance, and then the water phase is introduced into the gas hydrate generation reactor 1 from the water storage tank 3 so that the liquid surface S is higher than the liquid layer outlet 1c. L is introduced. This aqueous phase L may contain a stabilizer if necessary. Next, the water phase L in the gas hydrate production reactor 1 is cooled to a predetermined temperature of, for example, about 1 ° C. by the cooling coil 2, and thereafter, the temperature is controlled so as to maintain this temperature.

When the temperature of the aqueous phase L is stabilized at a predetermined temperature, methane in the gas storage unit 7 is continuously introduced as bubbles K from the methane inlet 1a. As a result, at least part of methane is absorbed into the aqueous phase L from the gas-liquid interface of the bubbles K, and reacts with water to be converted into methane hydrate (hydration reaction).
The methane hydrate MH generated by the reaction floats in the aqueous phase L because the density is smaller than the density of water, and the liquid surface S
Form a layer on top. This methane hydrate layer MH
The liquid is extracted from the liquid layer extraction outlet 1 c by the extraction pump 22, and is sent out to the dehydrator 30 through the pipe 20. At this time, methane hydrate is collected together with water,
It is in the form of slurry. As the methane hydrate layer MH is extracted from the liquid layer extraction outlet 1c, the liquid level S of the aqueous phase L is lowered, so that new water is discharged from the water storage tank 3 so that the level of the liquid level S is kept constant. The water is supplied into the gas hydrate production reactor 1 via the water supply pump 5.

When methane hydrate MH is generated in the gas hydrate production reactor 1, gas methane becomes solid methane hydrate MH, and the internal pressure decreases. On the other hand, in order to generate methane hydrate at high speed, the conditions in the gas hydrate generation reactor 1 must be set to a lower temperature and higher pressure. Therefore, in order to eliminate the pressure drop of the hydrate production vessel 1 due to the production of methane hydrate, the pressure in the gas hydrate production reactor 1 is continuously detected by the pressure gauge 11 and the flow rate is determined based on the pressure. The opening of the control valve 10 is continuously controlled. Thereby, the required amount of the raw material methane is replenished into the gas hydrate generation reactor 1, and the inside of the gas hydrate generation reactor 1 is maintained at a constant high pressure state, thereby achieving high-speed generation.

On the other hand, unreacted methane gas not absorbed in the aqueous phase L is released from the liquid surface S and accumulates as a gas phase G in the gas hydrate generation reactor 1. Unreacted water is extracted from the bottom of the gas hydrate production reactor 1, supercooled by a heat exchanger 18, and then sprayed in the gas hydrate production reactor 1 by a spray nozzle 14. Thus, the gas hydrate generation reactor 1
A large amount of supercooled water particles SP is released into the methane gas filled therein, which greatly increases the contact area per unit volume of the water particles SP with methane and immediately causes a hydration reaction. Generated to speed. The generated hydrate falls to the liquid surface S and is collected in the same manner as described above. When methane hydrate MH is generated in the gas hydrate generation reactor 1, a large heat of hydration is generated. On the other hand, in order to generate methane hydrate MH at high speed, the conditions in the hydrate generation vessel 1 must be set to a lower temperature and higher pressure state. Therefore, discharging the supercooled water particles SP into the gas hydrate generation reactor 1 also effectively removes the heat of hydration.

When the gas hydrate production reactor 1 is large, there is a possibility that the water at the bottom of the gas hydrate production reactor 1 may be in a supercooled state, and this water is taken out and directly, that is, without cooling. It may be sprayed on the upper part of the gas hydrate production reactor 1 as it is.

In the above-described embodiment, the bubbles K of methane rise in the aqueous phase L, so that the bubble interface can always be brought into contact with new water molecules without being covered with a high-viscosity reaction product. Is promoted. By continuing this operation in a stable state, high-concentration methane hydrate can be efficiently and continuously supplied to the dehydrating device 30.

If the particle diameter of the water particles SP ejected from the spray nozzle 14 is large, methane hydrate generated on the surface of the water particles impedes the supply of methane, so that the whole water particles SP may become methane hydrate. Can not.
Thus, by spraying gas together with water from the spray nozzle 14, the particle diameter of the water particles SP can be reduced to about 10 μm on average. The number of spray nozzles 14 is not limited to one, and a plurality of spray nozzles may be provided. Another method for reducing the average particle size of water particles to about 10 μm is shown in FIG.
As shown in (b), the gas hydrate generation reactor 1
An ultrasonic vibration plate 90 is provided in the upper part of the inside, and supercooled water is supplied from the pipe 15 onto the ultrasonic vibration plate 90 to form a water film 91, and the water particles SP are released from the water film 91 by ultrasonic vibration. May be. In this case, the particle diameter of the water particles SP becomes more uniform, and no adverse effect is caused by the ejection of the gas.

In general, the reaction between methane and water proceeds at a pressure of 40 atm or more, for example, when the reaction temperature is 1 ° C. Therefore, the gas hydrate production reactor 1 requires a high-pressure vessel with a pressure resistance of at least 40 atm. When it is desired to carry out the reaction at a higher temperature and lower pressure, it is preferable to add a stabilizer to the aqueous phase L. Examples of stabilizers that can shift the hydration reaction of methane to higher temperature and lower pressure include aliphatic amines such as isobutylamine and isopropylamine; alicyclic ethers such as 1,3-dioxolan, tetrahydrofuran and furan. And cyclobutanone,
Alicyclic ketones such as cyclopentanone; aliphatic ketones such as acetone; Since all of these stabilizers have a hydrocarbon group and a polar group in the molecule, each polar group attracts a water molecule and the hydrocarbon group attracts a methane molecule, thereby reducing the intermolecular distance. It is thought to promote the hydration reaction. For example, by adding an aliphatic amine, 10 ° C., 20 kg / cm 2
The reaction at G becomes possible, and the reaction at 10 ° C. and 10 kg / cm 2 G or less becomes possible depending on the addition of tetrahydrofuran. These stabilizers are used in an amount of 0.1 per 1000 g of pure water.
It is preferable to add within the range of 10 to 10 mol.

The reaction temperature depends on the above-mentioned relation of the production equilibrium.
It is better to be as low as possible. For example, it is preferable to control the aqueous phase temperature in the gas hydrate production reactor 1 to be in the range of 1 to 5 ° C. As a result, the solubility of methane in water can be increased, and the production equilibrium pressure can be reduced. The reaction of generating methane hydrate is an exothermic reaction, and when the reaction is started in the gas hydrate generating reactor 1, the temperature in the system rises due to heat of hydration, so that the temperature in the system is always maintained within a predetermined range. It is preferable to control the temperature so that the temperature is controlled.

The slurry-like methane hydrate produced efficiently and supplied to the dehydrator 30 is first subjected to the first dehydration by the dehydration screen 44, and further to the three-stage press dehydrator 46. , And a second dehydration is performed. Excess water dewatered by the dewatering screen 44 and the press dewatering machine 46 is returned to the water storage tank 3 through the pipe 49. As a result, the slurry-like methane hydrate introduced into the screw extruder 33 from the inlet 36 has a considerable amount of water removed. Further, when the pressurized methane gas is supplied from the pressurized gas introduction pipe 42, the methane gas reacts with the surplus water to generate methane hydrate, so that the generation amount of methane hydrate increases, and the methane hydrate is further used for generation. The amount of excess water can be reduced by the amount. Therefore, the withstand pressure of the discharge device main body 31 which is a pressure vessel is preferably the same as the withstand pressure design of the gas hydrate generation reactor 1 described above.

Here, the operation of the screw extruder 33 at the start of operation will be briefly described. At the start of operation, the screw extruder 33 closes an outlet sealing means (not shown) to keep an outlet 39 serving as an opening of the unloading device main body 31 as a pressure vessel in a sealed state. When the screw extruder 33 is operated in this state, the excess water contained in the slurry-like methane hydrate is further dehydrated, and the solid (powder) methane hydrate is compacted in the casing. Further, since the cooling means 41 cools the methane hydrate to a predetermined temperature (about −30 ° C.), the methane hydrate molded article does not have to be decomposed even when taken out to the atmosphere. However, since the outlet 39 is closed, the methane hydrate is pressed toward the outlet 39 and accumulates, and finally the inside of the casing is filled with the compacted and cooled methane hydrate compact. As a result, the outlet 39 can be sealed by the frictional force of the methane hydrate compact filled in the screw extruder 33.

After such a state, when the outlet sealing means is opened and the operation of the screw extruder 33 is continued,
The methane hydrate compact is continuously extruded from the outlet 39 into the atmosphere, and a long methane hydrate compact having a cross-sectional shape of the outlet 39 can be taken out. Here, when the cross section of the outlet 39 is made a rectangular cross section and sequentially cut to an appropriate length by the cutting means 43, a block 50 of a methane hydrate formed body formed into a rectangular parallelepiped or cubic shape is obtained.
Can be continuously formed. The methane hydrate block 50 thus formed is transported to a predetermined storage facility by transport means such as a belt conveyor 51.
It should be noted that the methane hydrate block 50 is not only easier to handle than a slurry or a powder, but also has a volume that is about half the volume of a powder containing air. Stacking can be performed efficiently without forming useless space.

Next, a second embodiment of the present invention will be described with reference to the drawings. The components already described in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. A gas hydrate dehydrator (hereinafter, dehydrator) shown in FIGS. 6 and 7 includes a pressurized dehydrator 60 that pressurizes and dehydrates gas hydrate generated in a slurry state in the gas hydrate generation reactor 1, A hydration dehydration device 70 that reacts water remaining in gas hydrate physically dehydrated by the pressure dehydration device 60 with methane gas to form a hydrate is formed.

The pressure dewatering device 60 is in the form of a so-called screw press, and has a container body 61 having a cylindrical internal space 61a and a spiral ridge 62a on the side surface, and is disposed in the internal space 61a. The shaft body 62 is provided.

At the tip of the container 61, an inlet 61b for taking the gas hydrate formed in a slurry state in the gas hydrate generation reactor 1 into the internal space 61a.
Is provided. The above-described pipe 2 is provided in the intake port 61b.
0 is connected. The container body 61 has a double structure of an inner wall 61c forming an inner space 61a and a housing 61d forming an outer shell, and the inner wall 61c is mesh-processed.
A drain port 61 for discharging water collected inside is provided in the housing 61d.
e is provided. The drain port 61e is connected to the water storage tank 3 via a pipe 63.

The shaft body 62 is formed so that the ridge 62a is formed in the internal space 61.
a, and is supported so as to be rotatable in a predetermined direction about its own axis.
4 is driven to rotate.

At the end of the container 61, an outlet 61f for taking out the gas hydrate conveyed by the rotation of the shaft 62 is provided. The outlet 61f is connected to the pipe 65
Is connected to the subsequent hydration dehydration apparatus 70 via the. A seal member 66 is provided between the outlet 61f and the shaft 62.

The hydration dehydration device 70 is in the form of a screw conveyor, and includes a container body 71 having a cylindrical internal space 71a having an oblong cross section, and spiral ridges 72a, 73a on the side surfaces. Two shafts (stirring means) 72, 73 which are arranged in the internal space 71a and convey gas hydrate while rotating individually; gas supply means 74 for supplying methane gas to the internal space 71a; A cooling means 75 for cooling the gas hydrate contained in the gas hydrate 71a.

At the tip of the container 71, a pressure dehydrator 60
Is provided with an inlet 71b for taking in the gas hydrate dehydrated under pressure. The above-described pipe 65 is connected to the intake 71b.

The shafts 72 and 73 are arranged in parallel with each other, and when viewed from the axial direction, the respective ridges 72a and 7
3a are arranged so as to overlap. Further, the respective protruding ridges 72a, 73a are arranged close to the inner surface of the internal space 71a, are rotatably supported around their own axis, and are rotationally driven by the driving unit 76. . The directions of rotation of the two shafts may be the same or different.

At the end of the container 71, an outlet 71c for taking out the gas hydrate conveyed by the rotation of the shafts 72, 73 is provided. Also, the outlet 71c
A sealing member 77 is provided between the shaft members 72 and 73.

A gas supply hole 71d for supplying methane gas to the internal space 71a is provided on a side surface of the container 71 near the outlet 71c. The gas supply hole 71d is connected to the pipe 8
Is connected to the gas storage unit 7 through a pipe 78 branched from the gas storage unit 7. The pipe 78 is provided with a valve 79 and a flow control valve (control means) 80 to constitute a gas supply means 74.

On the other hand, a pressure gauge (detection means) 81 for detecting the pressure of the internal space 71a is provided inside the container body 71 near the inlet 71b, and the opening of the flow control valve 80 is determined by the pressure gauge. On the basis of the measured value of 81, natural gas is replenished to the internal space 71a to constantly generate the internal pressure (for example, 40a).
tm).

Inside the shafts 72 and 73, there are formed flow paths 82 having a double pipe structure which reciprocate in the axial direction.
A cooling medium supply unit 83 is connected to the flow path
The propane whose component is adjusted as a refrigerant is introduced into the flow path 82 and is drawn out from the outside to cool the gas hydrate contained in the internal space 71a.

Next, a dehydration operation by the dehydrator configured as described above will be described. The gaseous hydrate in a slurry state supplied to the pressurized dehydrator 60 through the pipe 20 is accommodated in the internal space 61a through the inlet 61b, is conveyed in the axial direction by the rotation of the shaft 62, and is pressurized in the process. It is dehydrated by. The water removed from the gas hydrate is collected inside the housing 61d through the mesh of the inner wall 61c, and is guided from the drain port 61e to the water storage tank 3 through the pipe 63.

On the other hand, the gas hydrate pressurized and dehydrated with the rotation of the shaft 62 is taken out of the pressure dehydrator 60 through the outlet 61f, and supplied to the hydration dehydrator 70 through the pipe 65.

The gas hydrate supplied to the hydration dehydration device 70 is housed in the internal space 71a through the intake 71b, and is conveyed in the axial direction by the rotation of the shafts 72, 73. The hydrate is formed by reacting the remaining moisture and methane gas by cooling while stirring. Referring to FIG. 8 in detail, in the process of transporting the gas hydrate, unhydrated methane gas is supplied to the internal space 71a from the gas storage unit 7 through the gas supply holes 71d under pressure, and the internal space 71a The inside is kept at the production temperature described above. In this atmosphere, the gas hydrate moves complicatedly by the rotation of the shafts 72 and 73, and moves while constantly updating the contact surface with the unhydrated methane gas. Unhydrated methane gas comes into active contact with the renewed contact surface and reacts with moisture adhering to the gas hydrate particle surface to hydrate one after another. The hydration reaction in this case involves heat generation, but heat is recovered by cooling the shafts 72 and 73 with propane gas flowing through the respective flow paths 82, and the temperature inside the internal space 71a is always kept constant. Dripping. By the way, when methane gas is hydrated, the volume is drastically reduced, so that the internal pressure of the internal space 71a is rapidly reduced. When the decrease in the internal pressure is detected by the pressure gauge 81, the opening of the flow control valve 80 is controlled so as to replenish the internal space 71a with natural gas and maintain the internal pressure at the generated pressure.

The gas hydrate contained in the internal space 71a is dehydrated by the hydration reaction of unreacted methane gas with most of the remaining water by the time the gas hydrate reaches the outlet 71c. The rate itself is increased and taken out from the hydration dehydrator 70. The removed gas hydrate is stored in a dedicated transport container (not shown), and stored and transported.

According to the dehydrator configured as described above, the gas hydrate in the form of slurry is supplied to the dehydrator 60 under pressure.
Is physically dehydrated by using water, and the gas hydrate that has been dehydrated to a certain extent is chemically dehydrated by hydrating the remaining water and methane gas using a hydration dehydration device 70 to form a slurry. The gas hydrate can be efficiently dehydrated to significantly reduce the water content.

In the hydration dehydrator 70, when the reaction with the water remaining in the gas hydrate proceeds and the gas decreases, this is detected and the methane gas is replenished into the internal space 71a, thereby causing the hydration reaction. Since the dehydration action occurs continuously, a decrease in the water content can be promoted. By the way, the reaction between the remaining moisture and the gas progresses more rapidly as the pressure is higher. Therefore, in the hydration dehydration device 70, by arranging the pressure gauge 81 on the inlet 71b side where the pressure is relatively low and the reaction hardly occurs, the reaction state inside the container body 71 can be more accurately grasped, and the internal space 7
The supply of methane gas to 1a can be carried out in an amount suitable for the reaction situation.

In the hydration dehydrating apparatus 70, the shaft 72,
73 is a double pipe structure for the refrigerant flow
By introducing propane gas into the inside of 2 and extracting it from the outside, the gas hydrate can be efficiently cooled by using the thermal energy of propane gas as a refrigerant without waste.

In this embodiment, the container 71 and the shafts 72, 73 of the hydrating and dehydrating apparatus 70 are horizontally installed. However, in another embodiment, the gas hydrate outlet 71c is provided. The container body 71 and the shaft bodies 72 and 73 are vertically
Alternatively, they may be arranged inclined. According to this, when the dehydrated gas hydrate is exposed so as to be pushed out from the outlet 71c, it is sequentially dropped or slid down by the action of gravity and is taken out from the hydration dehydrator 70. Can be easily loaded into the system.

In the present embodiment, the hydration dehydrator 70 is provided with two shafts 72 and 73. However, the number of shafts is not limited to two, and there is no problem even if three or more shafts are used. .

[0080]

According to the present invention described above, the following effects can be obtained. (1) Since a gas hydrate in a slurry state can be dehydrated, compacted, molded and cooled in a single pressure vessel and a gas hydrate molded body can be continuously taken out to the atmosphere, high pressure in a gas hydrate production plant can be obtained. The number of containers can be reduced, and the construction cost of equipment can be reduced. For this reason, the production cost of the gas hydrate can be significantly reduced due to a significant decrease in the initial cost. (2) Since gas hydrate, which is easy to handle and has excellent volumetric efficiency and is obtained by solidifying powder in a block shape, can be continuously produced, the efficiency of storage and transportation is greatly improved, especially in terms of space. This can also contribute significantly to cost reduction. (3) By introducing a pressurized gas of a gas hydrate-forming substance into the main body of the extraction device, it is possible to generate a gas hydrate by additionally reacting with the remaining excess moisture. This increases the amount of gas hydrate generated,
In addition, excess water can be reduced. (4) Multi-stage dehydration can be performed continuously, such as primary dehydration by a dehydration screen, secondary dehydration by a mechanical dehydrator such as a press dehydrator, and final dehydration by a screw dehydration compacting means. Thus, a gas hydrate having a high dehydration rate can be produced. Therefore, it is possible to produce a gas hydrate having extremely low moisture content,
Since the temperature is set to a low temperature of about 0 ° C., it is possible to prevent the water from becoming ice and increasing the volume of the gas hydrate molded body. (5) The gas hydrate that has been dehydrated to some extent is chemically dehydrated in such a manner that the remaining moisture and the gas before hydration are subjected to a hydration reaction, so that the gas hydrate in a slurry state is efficiently dehydrated. As a result, the water content can be remarkably reduced, whereby the cost for storing and transporting the gas hydrate can be greatly reduced.

[Brief description of the drawings]

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

FIG. 2 is a perspective view showing a configuration example of a press dehydrator installed in the gas hydrate dehydrator of FIG.

FIG. 3 is a diagram showing a configuration example of a gas hydrate production apparatus incorporating the gas hydrate dehydration apparatus of FIG. 1;

4 (a) is an enlarged view of the spray means shown in FIG. 3, and FIG. 4 (b) is a view showing another embodiment of the spray means.

FIG. 5 is a hydrate generation equilibrium diagram.

FIG. 6 is a configuration diagram showing a second embodiment of a gas hydrate dehydrator according to the present invention.

FIG. 7 is a diagram showing a configuration example of a gas hydrate production apparatus incorporating the gas hydrate dehydration apparatus of FIG. 6;

FIG. 8 is a diagram illustrating a state inside the hydration dehydration apparatus.

FIG. 9 is a diagram showing a molecular structure of a hydrate.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 gas hydrate generation reactor 2 cooling coil 3 water storage tank 5 water supply pump 7 gas storage unit 10 flow control valve 12 gas field 13 acid gas removal step 14 spray nozzle 17 circulation pump 18 heat exchanger (cooler) 22 extraction Pump 30 Gas hydrate dewatering device (dewatering device) 31 Extraction device main body 32 Supply port 33 Screw extruder (Screw dewatering consolidation means) 36 Inlet 37 Drain port 39 Outlet 40 Consolidation part 41 Cooling means 42 Pressurized gas supply pipe 43 Cutting means 44 Dehydration screen 46 Press dehydrator 47 Barrier plate 48 Notch 50 Block 60 Pressure dehydrator 70 Hydration dehydrator 71a Internal space 71 Container body 72a, 73a Ridge 72, 73 Shaft (stirring means) 74 Gas supply means 75 Cooling means 80 Flow control valve (control means) 81 Pressure Total (detecting means) MH methane hydrate SP water particles

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B01J 3/02 B01J 3/02 101A 3/04 F C07B 61/00 C 63/02 B 101 C07C 5/00 3/04 7/20 C07B 61/00 9/04 63/02 C10L 3/00 B C07C 5/00 B01D 37/06 7/20 9/04 (72) Inventor Katsuo Ito Wadazaki, Hyogo-ku, Kobe City, Hyogo Prefecture 1-1-1 Machi Kobe Shipyard, Mitsubishi Heavy Industries, Ltd. (72) Inventor Satoshi Uehara 1-1-1, Wadasaki-cho, Hyogo-ku, Kobe-shi, Hyogo Prefecture Kobe Shipyard, Mitsubishi Heavy Industries, Ltd. (72) Kozo Yoshikawa, inventor 2-1-1, Niihama, Arai-machi, Takasago City, Hyogo Prefecture Inside the Takasago Research Laboratory, Mitsubishi Heavy Industries, Ltd. (72) Inventor, Hirotsugu 2-1-1, Niihama, Arai-machi, Takasago City, Hyogo Prefecture Mitsubishi Heavy Industries, Ltd. In the laboratory (72) Inventor Haruhiko Ema 2-1-1 Shinhama, Araimachi, Takasago City, Hyogo Prefecture Inside the Takasago Research Laboratory, Mitsubishi Heavy Industries, Ltd. (72) Inventor: Yuichi Kondo 1-1-1, Wadazakicho, Hyogo-ku, Kobe-shi, Hyogo Prefecture Inside Kobe Shipyard, Mitsubishi Heavy Industries, Ltd. 1-1 1-1 Mitsubishi Heavy Industries, Ltd.Kobe Shipyard (72) Inventor Hitoshi Endo 1-1-1, Wadasaki-cho, Hyogo-ku, Kobe-city, Hyogo Prefecture Inside Kobe Shipyard, Mitsubishi Heavy Industries, Ltd. (72) Inventor Yoshihiro Kita Hyogo Prefecture 2-1-1, Niihama, Arai-machi, Takasago-shi Inside the Mitsubishi Heavy Industries, Ltd. Takasago Research Laboratory

Claims (17)

[Claims] 1. A gas hydrate production apparatus comprising: a gas hydrate production reactor for producing a slurry gas hydrate from a raw material gas; and a gas hydrate dehydration apparatus for dehydrating the produced slurry gas hydrate. Wherein the gas hydrate dehydrator is included in the gas hydrate during or after dehydration by the physical dehydration means for physically dehydrating the generated slurry-like gas hydrate. A hydrate dehydrating means for hydrating by reacting water with a raw material gas. 2. A gas hydrate dehydration apparatus for dehydrating and solidifying a slurry gas hydrate supplied from a gas hydrate production reactor and extracting the dehydrated solid under the atmospheric pressure, wherein the slurry gas hydrate is provided at an upper part of a pressure vessel. An unloading device main body provided with a supply port, a screw dewatering consolidation molding device provided at a lower part in the unloading device main body and having a drainage port and an outlet sealing means, and a cooling unit for cooling the vicinity of the outlet of the screw dehydration consolidation molding means And a gas hydrate dehydration apparatus characterized by comprising: 3. A pressurized gas introduction pipe is connected above the screw dewatering consolidation means of the unloading device main body, so that a gas hydrate forming substance can be supplied into the unloading device main body. The gas hydrate dehydration apparatus according to claim 2. 4. A gas hydrate dewatering apparatus according to claim 2, wherein a cutting means for cutting the gas hydrate molded body to a predetermined length is provided at an outlet of said screw dewatering compacting means. . 5. The screw dewatering consolidation means has an outlet portion having a rectangular cross section.
5. The gas hydrate dehydrator according to any one of items 1 to 4. 6. The gas hydrate dehydration according to claim 2, wherein a dehydration unit for dehydrating surplus water from the introduced slurry gas hydrate is provided below the supply port. apparatus. 7. The gas hydrate dehydration according to claim 6, wherein the dehydration means includes one or both of a dehydration screen and a mechanical dehydrator for mechanically dehydrating. apparatus. 8. The gas hydrate dehydrator according to claim 7, wherein the mechanical dehydrator is a press dehydrator. 9. The gas hydrate dehydrator according to claim 8, wherein the press dehydrator is arranged in a plurality of stages in a vertical direction. 10. An overflow in which a weir plate is provided opposite to both side surfaces of the press dewatering machine, and a substantially center of an upper end portion of the weir plate located above the roller surface is cut out to drain dewatered excess water to the side surface. 10. The gas hydrate dehydrator according to 8 or 9, further comprising a flow path. 11. A gas hydrate dehydrator for dehydrating slurry gas hydrate, comprising: a container having an internal space for accommodating the gas hydrate; and a raw material before being hydrated in the internal space. Gas supply means for supplying gas; cooling means for cooling gas hydrate housed in the internal space; and stirring means for bringing the raw material gas into contact with the gas hydrate and stirring the gas hydrate in the internal space. A gas hydrate dehydration apparatus characterized by the above-mentioned. 12. The gas hydrate dehydration apparatus according to claim 11, further comprising pressure dehydration means for depressurizing and dehydrating the slurry-like gas hydrate before being stored in the container body. 13. The agitating means comprises a plurality of shafts having a spiral ridge on a side surface and arranged in the internal space to convey gas hydrate while rotating individually. The gas hydrate dehydrator according to claim 11 or 12. 14. The stirring means comprises two of the shafts, the shafts are arranged in parallel, and the projections are arranged so as to overlap each other when viewed from the axial direction. The gas hydrate dehydration apparatus according to claim 13, wherein 15. A fuel cell system comprising: a detecting unit that detects a reaction state between a gas hydrate and a gas contained in the internal space; and an adjusting unit that adjusts a gas supply amount according to the reaction state. The gas hydrate dehydrator according to any one of claims 11 to 14. 16. The gas hydrate dehydration apparatus according to claim 15, wherein said detection means is arranged in proximity to a gas hydrate intake provided in said container. 17. The gas hydrate outlet provided in the container body is disposed lower than the gas hydrate inlet port provided in the container body. A gas hydrate dehydration apparatus according to any one of claims 1 to 4.