JP2003252804A - Method for producing hydrate and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To produce a hydrate at a high concentration in a small-sized apparatus with high efficiency by efficiently reacting a hydrate-forming gas with water. <P>SOLUTION: The apparatus is designed to bring the water into contact with the hydrate-forming gas under a prescribed pressure and thereby produce the hydrate by a hydrating reaction. The apparatus is equipped with a hydrate- producing apparatus 1 composed of a mixer 3 for mixing the water with the hydrate-forming gas and a cooler 5 for cooling the resultant mixed fluid from the mixer 3 and producing a hydrate-forming fluid and a separating tank 2 for introducing the hydrate-forming fluid from the hydrate-producing apparatus 1 and separating the hydrate by a specific gravity difference from water. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydrate manufacturing method and apparatus for reacting a hydrate-forming gas (for example, methane) with water to produce a high-concentration hydrate with high efficiency in a small facility. It is a thing.

[0002]

2. Description of the Related Art In recent years, fuels for business and industrial use have been required to have low CO ₂ emission as a measure against global warming. Therefore, natural gas with low CO ₂ emission per unit combustion amount. Etc. are being used.

[0003] Natural gas is a gas containing ethane, propane and butane in the main component of methane by a few percent. When transporting or storing natural gas, the natural gas is liquefied natural at an extremely low temperature of -162 ° C or lower. It is transported or stored as gas (LNG). When using natural gas as a fuel, a liquefaction plant for liquefying natural gas, an LNG ship and a storage facility capable of transporting and storing natural gas at extremely low temperatures are required, and large-scale equipment cost, transportation cost and operation are required. There was a costly problem. For this reason, conventionally, it has been generally possible to use only for a large-scale collection site where a large amount of natural gas can be collected.

On the other hand, in addition to the large-scale natural gas sampling sites described above, there are many medium and small-scale natural gas sampling sites. At present, the natural gas in the small-scale natural gas collection area is not used.

Therefore, it has been considered to immobilize a large amount of natural gas in an easy-to-handle state, and one of them is hydrate.

In the hydrate, hydrocarbons (hydrate forming gas) such as methane, ethane, propane and butane, which are components of natural gas, are trapped in a cage structure formed by weakly binding water molecules. It is a sherbet-like solid compound, and when producing a hydrate, 0 to
A hydrate-producing gas such as methane (10-70ata) is blown into water at 10 ° C, and heat of hydrate formation (98
The hydrate is produced by cooling to remove (kcal / kg). When the temperature of hydrate rises due to the heat of formation, the production efficiency drops significantly, while even if the temperature rises, if the pressure is high, the production of hydrate can be secured.

Therefore, in order to produce a hydrate,
It is advantageous to cool the water as low as possible without freezing, which allows the hydrate to be produced with high efficiency and at a low pressure.

As described above, the hydrate can be manufactured at a relatively high temperature and low pressure as compared with the liquefied natural gas system, so that the manufacturing facility can be made small and inexpensive, and the hydrate can be used. Since it is stable as a solid, it is easy to handle such as storage and transportation. Therefore, it can be easily applied to the small and medium-sized natural gas collection sites as described above, and has not been used conventionally. Natural gas from a small-scale natural gas collection site can be effectively used.

Conventionally, a methane hydrate production apparatus as shown in FIG. 5, for example, has been generally known. In this apparatus, water is supplied from a lower portion into a pressure-resistant reaction vessel 50 through a water injection pipe 51 to maintain a predetermined level, and methane is introduced into water in the reaction vessel 50 by a methane introduction pipe 52. The hydrate is supplied to bring the bubbles of methane into contact with water to cause a hydration reaction to generate hydrate. At this time, the pressure in the upper space of the reaction vessel 50 is measured by the pressure gauge 53, and the regulating valve 54 provided in the methane introducing pipe 52 is controlled so that the detected pressure becomes a predetermined pressure. Further, a heat exchanger 55 for cooling water is provided in the lower part of the reaction vessel 50 to remove the heat of formation of hydrate formation by the hydration reaction.

Therefore, methane and water are brought into contact with each other under a predetermined pressure to produce a hydrate by a hydration reaction, and the produced hydrate floats and floats on the surface of the water phase.
And the hydrate layer 56 is taken out by a hydrate take-out pipe 57.

Further, the water at the bottom of the reaction vessel 50 is taken out by a circulation pipe 58, and is circulated by a circulation pump 59 to a spray nozzle 60 at the top of the reaction vessel 50 to spray the water, so that the sprayed water is in the upper portion of the reaction vessel 50. It makes contact with space methane to increase the rate of hydrate formation.

In order to produce hydrate using the hydrate producing apparatus shown in FIG. 5, methane is first introduced into the reaction vessel 50 through the methane introduction pipe 52 to eliminate air in the reaction vessel 50, and then a water injection pipe. Water is injected from 51 to a predetermined level, cooled by a heat exchanger 55 and stabilized at a predetermined temperature of 0 to 10 ° C. In this state, when methane is introduced by the methane introduction pipe 52 so that the inside of the reaction vessel 50 is maintained at a predetermined pressure and water is injected from the water injection pipe 51, water is generated by contact between the water bubbles of methane blown into the water and the water. A hydrate is produced by the sum reaction. The heat of hydrate formation by this hydration reaction is removed by the heat exchanger 55.

Further, the water at the bottom of the reaction vessel 50 is circulated to the spray nozzle 60 by the circulation pump 59 and sprayed to improve the contact between methane and water in the upper space of the reaction vessel 50 to hydrate. I try to increase the generation rate of.

[0014]

However, the conventional hydrate manufacturing apparatus is generally of a system in which water and methane are brought into contact with each other in the reaction vessel 50 to generate a hydrate, as shown in FIG. Therefore, it has the following problems.

That is, when water and methane are brought into contact with each other, a hydration reaction occurs by first absorbing methane in the water phase at the gas-liquid interface. However, as shown in FIG. When making contact with the bubbles, the hydration reaction occurs at the gas-liquid interface 61 shown in FIG. 6, so that the shell-shaped hydrate film 6 surrounds the bubbles 62 as shown in FIG.
3 is formed and the hydrate film 63 is formed, the hydration reaction ends there, and no more hydrate is generated. Therefore, there is a problem that the hydrate generation rate is reduced.

On the other hand, since the hydrate produced has a density smaller than that of water (theoretical density 0.915 g / cm ² ), it floats near the surface of the water phase due to the difference in specific gravity to form the hydrate layer 56, This hydrate layer 56 hinders the absorption of methane on the surface of the aqueous phase.

Further, in the conventional device as shown in FIG. 5,
Since the operation of bringing methane into contact with water and the operation of removing the heat of hydrate formation are all performed inside the reaction vessel 50, a large pressure-resistant reaction vessel 50 is required and the equipment cost increases. There is also a problem with a large reaction container 50
Even if a device to bring methane and water into contact with each other is made well, it is difficult to mix them uniformly, which also causes a problem that hydrate cannot be produced with high efficiency.

Further, in the conventional apparatus, as shown in FIG. 5, a heat exchanger 55 or the like is inserted into the reaction vessel 50 to remove the heat of hydrate formation by heat transfer. The water in contact is in a substantially stationary state, and there is a problem that good heat exchange cannot be performed because no convection occurs. Furthermore,
In the method in which the heat exchanger 55 is installed in the large reaction container 50 to cool it, a temperature difference occurs in the temperature in the reaction container 50, and therefore, a hydrate is generated with high efficiency and stability. It was difficult.

As described above, in the conventional apparatus in which water and methane are brought into contact with each other in the reaction vessel 50 to generate hydrate, and the heat of hydrate formation at that time is removed in the reaction vessel 50, Not only a large reaction vessel 50 is required, but it is difficult to make good contact between water and methane, and it is difficult to uniformly cool the methane, and therefore, there is a problem that a hydrate cannot be efficiently produced at a high speed. Was.

The present invention has been made in view of the above problems of the prior art, and efficiently makes a hydrate-forming gas react with water to make a high-concentration hydrate highly efficient with a small apparatus. It is an object of the present invention to provide a hydrate manufacturing method and a device thereof that can be manufactured.

[0021]

The invention according to claim 1 is a method for producing a hydrate by a hydration reaction by bringing water and a hydrate-forming gas into contact with each other under a predetermined pressure. A hydrate production method characterized in that a hydrate is produced by a hydrate production step of mixing with a hydrate-forming gas and cooling to a predetermined temperature, and then the hydrate-forming fluid is introduced into a separation tank to take out the hydrate. It is related to.

According to a second aspect of the present invention, the supply ratio of water and hydrate forming gas to the hydrate forming step is adjusted so that the hydrate forming fluid at the outlet of the hydrate forming step maintains fluidity. The present invention relates to the hydrate manufacturing method according to claim 1.

The invention according to claim 3 is characterized in that the hydrate-forming fluid at the outlet of the hydrate-producing step is stirred to homogenize the temperature to complete the hydration reaction. The present invention relates to a rate manufacturing method.

The invention according to claim 4 is characterized in that the cooling temperature is adjusted so that the hydrate-forming fluid at the outlet of the hydrate-producing step has a set temperature.
The method for producing a hydrate according to any one of 1 to 3 above.

The invention according to claim 5 relates to the hydrate production method according to any one of claims 1 to 4, characterized in that the water supplied to the hydrate production step is pre-cooled. is there.

According to a sixth aspect of the present invention, there is provided an apparatus for producing hydrate by contacting water and a hydrate-forming gas under a predetermined pressure to produce a hydrate, wherein the water and the hydrate-forming gas are mixed. Hydrate generator for cooling the mixed fluid from the mixer to generate a hydrate-forming fluid, and a hydrate for introducing the hydrate-forming fluid from the hydrate generator And a separation tank for separating the hydrate.

The invention according to claim 7 is the apparatus for producing hydrate according to claim 6, characterized in that the hydrate production device has a construction inserted in a tube.
It is related to.

In the eighth aspect of the present invention, the hydrate production apparatus includes a rear reactor at the outlet of the cooler, which completes the hydration reaction by stirring the hydrate-forming fluid to make the temperature uniform. The hydrate manufacturing apparatus according to claim 6 or 7, further comprising:

According to a ninth aspect of the present invention, a thermometer for detecting the temperature of the hydrate-forming fluid is provided at the outlet of the hydrate generator, and a cooler is used so that the temperature detected by the thermometer is maintained at a preset temperature. The hydrate manufacturing apparatus according to any one of claims 6 to 8, further comprising a temperature controller that controls a cooling temperature.

According to a tenth aspect of the present invention, the water injection pipe for supplying water to the mixer of the hydrate generator is provided with a precooler. The present invention relates to a hydrate manufacturing device.

The invention described in claim 11 is provided with a pump in a water injection pipe connected to the mixer of the hydrate generator, and an inlet pipe of the pump and a bottom portion of the separation tank are connected by a water pipe, The hydrate manufacturing apparatus according to any one of claims 6 to 10, wherein a water supply pipe is connected to the water guide pipe.

According to the twelfth aspect of the present invention, there is provided a return flow path for returning the unreacted hydrate-forming gas in the upper portion of the separation tank to the mixer of the hydrate generator by pressurizing the gas with a compressor. It is related with the hydrate manufacturing apparatus in any one of Claims 6-11 characterized by the above-mentioned.

The invention according to claim 13 is characterized in that the separation tank for introducing the hydrate-forming fluid separates the hydrate by the difference in specific gravity between the hydrate and water. The present invention relates to the hydrate manufacturing apparatus according to claim 1.

According to the above means, the following operations are performed.

In the hydrate production method and apparatus of the present invention, the hydrate production apparatus has a mixer for mixing water and a hydrate forming gas, and a cooler for cooling the mixed fluid from the mixer to a predetermined temperature. Since the hydrate is generated, it is possible to uniformly mix the water and the hydrate-forming gas with a small mixer to enhance the hydrate generation efficiency. Furthermore, the mixed fluid can be efficiently and uniformly cooled with a small cooler. That is,
In the cooler, since the mixed fluid flows inside the small structure at a high speed with respect to the heat transfer surface, hydrate does not adhere to and grow on the heat transfer surface, and the heat transfer performance is improved. The rate can be generated with high efficiency and reliability.

Further, by providing the rear reactor for stirring the mixed fluid downstream of the cooler, the temperature of the mixed fluid can be made uniform, and thereby the hydration reaction of the hydrate-producing gas can be carried out. It can be almost completed.

As described above, in the mixed fluid flowing through the mixer, the cooler, and the rear reactor which constitute the hydrate generator, the fine bubbles of the hydrate forming gas flow while being stirred in water. Therefore, the hydrate generated at the interface of the bubbles of the hydrate-forming gas is pulverized and dispersed in water, and the interface of the bubbles of the hydrate-forming gas is always in contact with water, so that the reaction is promoted. The reaction of the hydrate-forming gas is completed and completed, and the hydrate production efficiency is greatly enhanced.

Further, since the separation tank is used only for the operation of introducing the hydrate-forming fluid from the hydrate generator to separate the hydrate, the operation can be made simple and the structure can be made small.

Therefore, according to the hydrate manufacturing method and apparatus of the present invention, the entire apparatus can be miniaturized, and the hydrate can be manufactured with extremely high efficiency as compared with the conventional method.

The hydrate-forming fluid is separated by adjusting the supply ratio of water and hydrate-forming gas to the hydrate-forming step so that the hydrate-forming fluid at the outlet of the hydrate-forming step maintains fluidity. It will be possible to stably supply to the tank.

By adjusting the cooling temperature of the refrigerator so that the hydrate-forming fluid at the outlet of the hydrate-producing step has a set temperature, the temperature of the mixed fluid in the hydrate-producing device is stabilized to produce hydrate. The efficiency can be further increased. Furthermore, by pre-cooling the water supplied to the hydrate production process, the temperature inside the hydrate production apparatus can be stabilized.

By adopting a construction in which the hydrate generator is inserted into the tube, the hydrate generator can be downsized and the contact between water and the hydrate forming gas can be further improved.

If the separation tank for introducing the hydrate-forming fluid has a structure in which water and hydrate are separated by a difference in specific gravity, the hydrate can be easily separated, and the separation tank can be made small and simple.

[0044]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In the form example shown below, the case where methane is used as the hydrate forming gas will be described, but the hydrate forming gas is not limited to methane,
Hydrates can also be produced using ethane, propane, heptane, krypton, xenon and carbon dioxide.

FIG. 1 is a flow sheet showing an example of an embodiment of the present invention, showing a hydrate manufacturing apparatus. This hydrate production apparatus mainly has a hydrate production apparatus 1 and a separation tank 2 as a hydrate production process.

The hydrate generator 1 comprises a mixer 3 and
It has a configuration including a cooler 5 connected to the refrigerator 4 and a rear reactor 6. In the case of the hydrate generator 1 shown in FIG. 2, a case where the mixer 3, the cooler 5, and the rear reactor 6 are arranged in series inside the tube 8 to form a small structure is shown. ing.

Water is supplied to the mixer 3 of FIG. 1 through a water injection pipe 9. A precooler 10 is attached to the water injection pipe 9.
Is provided, and the upstream side of the water injection pipe 9 is a water injection valve 11
Is connected to a pump 12 via a water conduit 13 which is connected to the bottom of the separation tank 2. Therefore, the water at the bottom of the separation tank 2 is sucked by the pump 12 and supplied to the mixer 3. Further, a water supply pipe 15 having a water supply valve 14 is connected to the water guide pipe 13.

On the other hand, the mixer 3 has a flow control valve 16
Methane, which is a hydrate-forming gas, is supplied through a source gas pipe 17 provided with.

At this time, the raw material gas pipe 17 is, for example, as shown in FIG. 2, the porous member 1 installed inside the mixer 3.
The gas is supplied to the porous member 18 from the raw material gas pipe 17 and is connected to the gas generator 8. The fine gas bubbles of methane are generated in the water supplied to the mixer 3. or,
In mixing water and methane in the mixer 3, in addition to the above-described configuration, methane is blown into the water in the mixer 3 from a small port or a thin tube provided in the raw material gas pipe 17 to generate fine methane bubbles. It is possible to employ various methods such as the above method, a method in which a stirring device such as a rotary blade is provided inside the mixer 3, or a method in which the above methods are combined.

The cooler 5 shown in FIG. 2 has a structure in which a heat transfer tube 19 for circulating the refrigerant of the refrigerator 4 is arranged along the inside of the tube 8, and by cooling the mixed fluid inside the cooler 5, the hide I try to promote the generation of rates. At this time, the cooler 5 can be cooled to a supercooled state in which water is not frozen, for example, about 0 ° C to -3 ° C. As shown in FIG. 3, the cooler 5 causes the mixed fluid from the mixer 3 to flow through a thin tube 23 provided between the headers 20 and 21, and circulates a refrigerant between the headers 20 and 21, as shown in FIG. By doing so, it is possible to employ a system in which the mixed fluid is cooled through the narrow tube 23, or various other systems such as a shell-and-tube system and a plate system.

The cooler 5 shown in FIGS. 2 and 3 may be a direct cooling system in which the refrigerant cooled in the refrigerator 4 in FIG. 1 is circulated to cool the mixed fluid, or the refrigerator is used. An indirect cooling method may be used in which the intermediate refrigerant is cooled by 4 and the refrigerant circulated in the cooler 5 of FIGS. 2 and 3 is cooled by the intermediate refrigerant.

As shown in FIG. 2, for example, the rear reactor 6 is provided with an agitator 24 such as a swirl vane on the inner surface of the tube 8 to agitate the mixed fluid from the cooler 5. As the agitator 24, a groove is formed on the inner surface of the tube 8 in addition to the spiral blade as shown in FIG.
Alternatively, another obstacle may be provided to agitate the mixed fluid, or a cyclone may be provided to agitate the mixed fluid. Further, an ultrasonic oscillator may be provided to agitate the mixed fluid. You may make it sonic-stir. In this way, by stirring the mixed fluid with the stirrer 24 of the rear reactor 6, the temperature of the mixed fluid is made uniform, and thereby the hydration reaction of methane is substantially completed.

The hydrate-forming fluid from the hydrate generator 1 is introduced into the separation tank 2,
The separation tank 2 separates the hydrate from the hydrate forming fluid and takes it out. In the example of FIG. 1, the hydrate in the hydrate-forming fluid introduced into the separation tank 2 has a density lower than that of water (theoretical density 0.915 g /
cm ² ), it is floated on the surface of the aqueous phase due to the difference in specific gravity and is separated. Therefore, the separated hydrate can be taken out while maintaining the pressure in the take-out pipe 25 and the reaction vessel 50. It can be taken out continuously through the. A rotary feeder, a screw feeder, or the like can be used as the hydrate take-out device 25a.

The separation tank 2 is provided with a liquid level gauge 26, and the water supply pipe 15 is supplied with a detection signal from the liquid level gauge 26.
The liquid level controller 27 is provided so as to keep the liquid level in the separation tank 2 constant by adjusting the water supply valve 14 of FIG.

Unreacted methane accumulates in the upper portion of the inside of the separation tank 2, but the flow control valve 28 is provided in the upper portion of the separation tank 2.
And a return passage 31 including a dryer 29 and a compressor 30
The unreacted methane in the upper part of the separation tank 2 is connected to the compressor 3 after the moisture is removed by the dryer 29.
It is pressurized by 0 and returned to the mixer 3 together with methane from the raw material gas pipe 17.

A pressure gauge 32 is provided above the separation tank 2 and is connected to a pressure controller 33. The pressure controller 33 includes a flow rate control valve 16 of the raw material gas pipe 17 and a return passage. The opening degree of the flow rate control valve 28 of 31 is adjusted so that the pressure inside the separation tank 2 is maintained at an arbitrary set value within the range of about 10 to 70 ata.

In the above structure, the operation of the pump 12 is controlled so as to inject excess water into the mixer 3 sufficient for hydrating the methane supplied to the mixer 3.

Further, at the outlet of the hydrate generator 1, a thermometer 3 for detecting the temperature of the hydrate forming fluid.
4 is provided and is connected to the temperature controller 35, and the temperature controller 35 detects a temperature of the thermometer 34 of, for example, about 0.5 to 5.
The cooling temperature by the refrigerator 4 is controlled so that the set temperature is in the range of ° C. Further, at this time, the temperature controller 35 may finely control the opening of the water injection valve 11 provided in the water injection pipe 9 to finely adjust the outlet temperature of the hydrate generation device 1. At this time, the water injection pipe 9
If the temperature of the water to be poured is kept constant by the precooler 10 provided in the above, the temperature of the mixed fluid can be stably controlled by the temperature controller 35.

The operation of the above embodiment will be described below.

By operating the pump 12 in a state where water has flowed into the separation tank 2 to a predetermined water level in advance, the water supply from the water supply pipe 15 and the water in the separation tank 2 are generated through the water injection pipe 9 to produce hydrate. Supply to the mixer 3 of the device 1. Simultaneously with this water supply, methane pressurized by the raw material gas pipe 17 is supplied to the mixer 3 and mixed with the water. At this time,
The pressure controller 33 is a flow control valve 1 for the raw material gas pipe 17.
6 and the opening degree of the flow rate control valve 28 of the return flow path 31 are controlled so that the pressure inside the separation tank 2 is maintained at an arbitrary value within the range of 10 to 70 ata. At this time, since the liquid level controller 27 controls the opening degree of the water supply valve 14 so that the liquid level in the separation tank 2 is maintained at the set level, the pressure inside the separation tank 2 is stably controlled. .

In the mixer 3, as shown in FIG. 2, fine gas bubbles of methane are generated in the water by the porous member 18 and the like provided in the raw material gas pipe 17, so that it is possible to generate water by a small structure. Can mix methane uniformly.

The mixed fluid in which water and methane are uniformly mixed in the mixer 3 is subsequently supplied to the cooler 5 to be cooled.
The temperature at which the mixed fluid is cooled is preferably a temperature at which the mixed fluid can maintain fluidity and is as low as possible.
Therefore, the cooling temperature may be, for example, a temperature in a supercooled state of about 0 ° C to -3 ° C.

Therefore, the cooler 5 can immediately cool the mixed fluid from the mixer 3 and efficiently remove the heat of hydrate formation caused by the mixing of water and methane, so that the hydrate can be discharged at a high speed. It can be generated with high efficiency.

In the cooler 5 of FIG. 2, the mixed fluid is cooled by the heat transfer tube 19 in which the refrigerant from the refrigerator 4 circulates. In the cooler 5 of FIG. 3, while the mixed fluid flows through the thin tube 23. Since the mixed fluid is cooled by the refrigerant from the refrigerator 4, there is an effect that the mixing of water and methane is further promoted while the mixed fluid is in contact with the heat transfer tube 19 or while passing through the narrow tube 23. The rate generation efficiency can be further enhanced.

Further, since the mixed fluid flows at a high speed with respect to the heat transfer surface of the heat transfer tube 19 or the thin tube 23, the hydrate does not adhere to and grow on the heat transfer surface, and the hydrate does not transfer. Since the thermal performance is improved, the hydrate generation will be performed with higher efficiency.

Further, the hydrate-forming fluid that has exited the cooler 5 is introduced into the rear reactor 6 and is agitated by an agitator 24 such as a spiral blade provided inside the tube 8, whereby the temperature of the mixed fluid is increased. Are homogenized, and thereby the hydration reaction of methane is almost completed.

As shown in FIG. 4, the mixed fluid flowing through the mixer 3, the cooler 5, and the rear reactor 6 constituting the hydrate generator 1 described above has fine methane bubbles 36 stirred in water. However, since the hydrate 37 generated at the interface of the methane bubbles 36 is pulverized and dispersed in the water, the interface of the methane bubbles 36 is always in contact with water. Then, the reaction is promoted, and the reaction of methane is completed and completed. By substantially completing the reaction of methane in this way, the production efficiency of hydrate can be greatly increased.

On the other hand, the temperature of the hydrate forming fluid at the outlet of the hydrate generator 1 is detected by the thermometer 34, and the temperature is adjusted so that the detected temperature becomes a set temperature in the range of 0.5 to 5 ° C., for example. Since the controller 35 controls the cooling temperature by the refrigerator 4, the inside of the hydrate generator 1 is always stabilized at the set low temperature, and therefore the hydrate generation is always stable and highly efficient. You will be told.

The mixer 3, the cooler 5, and the rear reactor 6 of the hydrate producing apparatus 1 described above are provided inside the tube 8 as shown in FIG. It is possible to achieve uniform mixing of water and methane and uniform temperature of the mixed fluid due to its small size,
It is possible to generate a hydrate with higher efficiency.

Since the excess water sufficient for the hydration reaction of methane is injected into the mixer 3, the hydrate-forming fluid discharged from the hydrate generator 1 solidifies or has a significantly high viscosity. It can flow stably without rising, and thus the hydrate forming fluid from the hydrate generator 1 can be stably supplied to the separation tank 2.

The hydrate-forming fluid introduced into the separation tank 2 is separated into hydrate and water, and only the hydrate is taken out. The separation tank 2 of FIG. 1 shows a case where the hydrate is separated from the introduced hydrate-forming fluid by the specific gravity difference with water, and the hydrate separated on the surface of the water phase is removed by the take-out device 25a. The take-out pipe 25 provided is used to take out continuously.

As described above, the separation tank 2 only has the operation of separating the hydrate-forming fluid produced by the hydrate producing apparatus 1 into water and hydrate and taking out the hydrate, and therefore has a simple and compact structure. Can be The separation tank 2 may be separated by a method such as a screen or another method other than the method of separating water and hydrate by the difference in specific gravity as described above.

The hydrate production method and apparatus of the present invention are not limited to the above-mentioned embodiments, and various hydrocarbon gases other than methane can be used as the hydrate forming gas. Needless to say, various changes can be made without departing from the scope of the present invention.

[0074]

According to the hydrate production method and apparatus of the present invention, the hydrate production is provided with the mixer for mixing water and the hydrate forming gas and the cooler for cooling the mixed fluid from the mixer to a predetermined temperature. Since the hydrate is generated by the apparatus, there is an effect that the efficiency of hydrate generation can be increased by uniformly mixing water and the hydrate-forming gas with a small mixer. Furthermore, the mixed fluid can be efficiently and uniformly cooled with a small cooler. That is, in the cooler, the mixed fluid flows inside the small structure at a high speed with respect to the heat transfer surface, so that hydrate does not adhere to and grow on the heat transfer surface, and the heat transfer performance is improved. Therefore, there is an effect that hydrate can be generated with high efficiency and reliability.

Further, by providing the rear reactor for stirring the mixed fluid downstream of the cooler, the temperature of the mixed fluid can be made uniform, whereby the hydration reaction of the hydrate product gas can be carried out. There is an effect that can be almost completed.

As described above, in the mixed fluid flowing through the mixer, the cooler and the rear reactor constituting the hydrate generator, the fine bubbles of the hydrate forming gas flow while being stirred in water. Therefore, the hydrate generated at the interface of the bubbles of the hydrate-forming gas is pulverized and dispersed in water, and the interface of the bubbles of the hydrate-forming gas is always in contact with water, so that the reaction is promoted. There is an effect that the reaction of the hydrate-forming gas is completed to the end and thus the efficiency of hydrate formation is greatly increased.

Further, since the separation tank is used only for the operation of introducing the hydrate-forming fluid from the hydrate generator to separate the hydrate, there is an effect that the operation can be made simple and the structure can be made small.

Therefore, according to the hydrate manufacturing method and apparatus of the present invention, there is an effect that the entire apparatus can be miniaturized and the hydrate can be manufactured at high speed and high efficiency as compared with the conventional method.

Further, by adjusting the supply ratios of water and hydrate forming gas to the hydrate forming process so that the hydrate forming fluid at the outlet of the hydrate forming process maintains fluidity, the hydrate is always prepared. There is an effect that the fluidity of the forming fluid is maintained and can be stably supplied to the separation tank.

By adjusting the cooling temperature of the refrigerator so that the hydrate-forming fluid at the outlet of the hydrate-producing process reaches the set temperature, the temperature of the mixed fluid in the hydrate-producing device is stabilized to stabilize the hydrate. There is an effect that the production efficiency of can be further enhanced.

By pre-cooling the water supplied to the hydrate production step, the temperature inside the hydrate production apparatus can be stabilized.

The structure in which the hydrate generator is inserted in the tube has the effects that the hydrate generator can be downsized and the contact between water and the hydrate forming gas can be further improved.

If the separation tank for introducing the hydrate-forming fluid is configured to separate water and hydrate by the difference in specific gravity, the hydrate can be easily separated, and the separation tank can be made compact and simple.

[Brief description of drawings]

FIG. 1 is a flow sheet of a hydrate manufacturing apparatus according to an embodiment of the present invention.

FIG. 2 is a cut side view showing an example of the hydrate generation device of FIG.

FIG. 3 is a cut side view showing another example of the cooler shown in FIG.

FIG. 4 is an explanatory diagram showing a hydrate generation principle of the hydrate generation device according to the present invention.

FIG. 5 is an explanatory diagram of a gas-liquid interface between bubbles of methane gas and water in a conventional hydrate manufacturing apparatus.

FIG. 6 is an explanatory diagram showing a hydrate generation principle in a conventional hydrate manufacturing apparatus.

FIG. 7 is an explanatory diagram showing a state in which a shell-shaped hydrate film is formed in a conventional hydrate manufacturing apparatus.

[Explanation of symbols]

1 Hydrate generator 2 separation tanks 3 mixer 5 cooler 6 Rear reactor 8 tubes 9 Water injection pipe 10 Precooler 12 pumps 13 water conduit 15 water pipe 30 compressor 31 Return flow path 34 Thermometer 35 Temperature controller

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C10L 3/06 C10L 3/00 A (72) Inventor Masayoshi Hori 1st Shin-Nakahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Ishikawajima Harima Heavy Industries Co., Ltd. Machinery & Plant Development Center (72) Inventor Shoichiro Baba 1 Shin-Nakahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Ishi Kawashima Harima Heavy Industries Co., Ltd. Machinery & Plant Development Center (72) Inventor Ochiai Junichi Ishikawajima-Harima Heavy Industry Co., Ltd. 1 Shin Nakahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Machinery and plant development center (72) Inventor Masato Oguma Shin Nakahara-cho 1, Isogo-ku, Yokohama-shi, Kanagawa Ishi Kawashima Harima Heavy Industry Co., Ltd.・ F term in plant development center (reference) 4H006 AA05 AC90 AD33

Claims (13)

[Claims] 1. A method for producing a hydrate by contacting water and a hydrate-forming gas under a predetermined pressure to produce a hydrate, wherein water and the hydrate-forming gas are first mixed and cooled to a predetermined temperature. A method for producing a hydrate, which comprises producing a hydrate by a hydrate producing step, and subsequently introducing a hydrate-forming fluid into a separation tank to take out the hydrate. 2. The supply ratio of water and hydrate forming gas to the hydrate forming process is adjusted so that the hydrate forming fluid at the outlet of the hydrate forming process maintains fluidity. The hydrate production method described. 3. The method for producing a hydrate according to claim 1, wherein the hydrate-forming fluid at the outlet of the hydrate producing step is agitated to make the temperature uniform to complete the hydration reaction. 4. The method for producing a hydrate according to claim 1, wherein the cooling temperature is adjusted so that the hydrate-forming fluid at the outlet of the hydrate producing step has a set temperature. 5. The hydrate production method according to claim 1, wherein the water supplied to the hydrate production step is pre-cooled. 6. An apparatus for producing hydrate by contacting water and a hydrate-forming gas under a predetermined pressure to produce a hydrate, wherein the mixer is a mixer for mixing water and the hydrate-forming gas. A hydrate generator comprising a cooler for cooling the mixed fluid from to generate a hydrate-forming fluid, and a separation tank for introducing the hydrate-forming fluid from the hydrate generator to separate the hydrate, A hydrate manufacturing apparatus comprising: 7. The hydrate generator is configured to be inserted into a tube.
The hydrate manufacturing apparatus described. 8. The hydrate generator is equipped with a rear reactor at the outlet of the cooler to complete the hydration reaction by stirring the hydrate-forming fluid to make the temperature uniform. The hydrate manufacturing apparatus according to claim 6 or 7. 9. A temperature control for controlling a cooling temperature by a cooler such that a thermometer for detecting a temperature of a hydrate forming fluid is provided at an outlet of the hydrate generating device, and a cooling temperature by a cooler is controlled so that a detected temperature of the thermometer is maintained at a set temperature. A hydrate manufacturing apparatus according to any one of claims 6 to 8, further comprising a container. 10. The hydrate manufacturing apparatus according to claim 6, wherein the water injection pipe for supplying water to the mixer of the hydrate generating apparatus is provided with a precooler. 11. A pump is provided in a water injection pipe connected to the mixer of the hydrate generator, and an inlet of the pump and a bottom of the separation tank are connected by a water conduit, and a water supply pipe is connected to the water conduit. The hydrate manufacturing apparatus according to any one of claims 6 to 10, which is connected. 12. The method according to claim 6, further comprising a return flow path for returning unreacted hydrate-forming gas in the upper part of the separation tank to a mixer of the hydrate generator by pressurizing the gas with a compressor. 11. The hydrate manufacturing apparatus according to any one of 11. 13. The hydrate production method according to claim 6, wherein the separation tank for introducing the hydrate-forming fluid separates the hydrate by the difference in specific gravity between the hydrate and water. apparatus.