JP2006009864A - Method of storing and transporting gas clathrate and gas clathrate storage container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of storing and transporting gas clathrate and a gas clathrate storage container capable of easily, safely, and efficiently storing a gas as a clathrate by sealing the clathrate in the container in a pressure balanced state between the clathrate and the gas by noting the self-storability of the gas clathrate, easily decomposing the gas clathrate, and having excellent storage volume efficiency. <P>SOLUTION: In this method of storing the gas as the clathrate, the gas clathrate or its powder is stored by storing it in the container filled with a gas of the same type as the gas. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for storing and transporting a gas clathrate powder such as natural gas or a molded product thereof, and a gas clathrate storage container.

  Conventionally, a large amount of natural gas is stored and transported in a state where the natural gas is LNG, that is, liquefied natural gas. However, in order to store natural gas by this method, it is necessary to cool the natural gas to −162 ° C. and keep it at that temperature. For this reason, the manufacturing equipment and storage equipment such as expensive tanks are expensive, and in this method, a ship or vehicle having storage equipment such as expensive tanks is required to transport LNG.

  On the other hand, as a method for efficiently storing and transporting a large amount of natural gas, it has been studied and studied to convert natural gas into a gas clathrate (clathrate hydrate or gas hydrate). The stable condition of the clathrate of methane, which is the main component of natural gas, requires cooling to −85 ° C. under atmospheric pressure, but its decomposition is suppressed even in a temperature range higher than that, and gas storage, There are also reports that transportation is possible. On the other hand, when industrially producing clathrate from gas such as natural gas, a general steel material cannot be used as a constituent material of the equipment at −50 ° C. or lower, and the refrigerant of the refrigerator becomes special. Therefore, it is economically disadvantageous in terms of both equipment costs and operating costs. For this reason, research and examination for storing and transporting natural gas for a long time at -50 ° C or higher under atmospheric pressure with the aim of realizing a gas storage and transport method using gas clathrate. Has been made.

It is said that the slow decomposition of methane clathrate in the temperature range of −85 ° C. or more is due to a phenomenon that an ice film is formed on the surface of the clathrate by gas decomposition, that is, self-preserving property. From this viewpoint, as a hydrate storage method, by spraying water on the surface of the synthesized powder hydrate, forming a thin ice film by subcooling at −20 to −5 ° C., and then pelletizing, A method for improving the self-preserving property while increasing the strength of gas hydrate has been proposed (see Patent Document 1).
Japanese Patent Laid-Open No. 2002-220353 (FIG. 1)

  Since natural gas stored as hydrate is utilized by decomposition of hydrate, the decomposition operation needs to be easy. When the ice film is formed on a powdery gas hydrate with a large specific surface area and then molded as in the above preservation method, it is necessary to unravel the molded state to release the gas. In addition, it is necessary to release the gas inside the hydrate by solving the individually formed ice film of the powder hydrate. However, it is difficult to release the powder hydrate because an ice film is formed on each powder hydrate. For example, when the release is performed by heating, a heating amount corresponding to the degree of molding or stability of the molded body is required.

  In addition, according to the above storage method, since water is directly sprayed and brought into contact with powdery methane hydrate having a large specific surface area, the hydrate is decomposed by the latent heat of water, and the inside of the hydrate and the hydrate Since the contained methane is released out of the hydrate, the amount of gas per unit volume is reduced. In addition, it is highly possible that part of the water sprayed on the hydrate freezes in the manufacturing facility and causes trouble. Furthermore, since the ice layer is coated on the outer periphery of the pellet of the gas hydrate powder, the volume is increased, and the storage volume efficiency is poor.

  In view of the above-mentioned problems that occur when storing or transporting a gas as a hydrate, the present invention focuses on the self-preserving property of the gas clathrate, and the pressure equilibrium phenomenon between the clathrate and the gas body. By sealing the clathrate in a container under the condition below, when storing and transporting the gas as a clathrate, it can be stored and transported easily, safely and efficiently, and the gas clathrate is decomposed. It is an object of the present invention to provide a gas clathrate storage method and transport method, and a storage container that can be easily operated and have a high storage volume efficiency.

  The present invention employs the following means (1) to (14) in order to solve the above problems.

  (1) The gas clathrate storage method according to the first means is a method of storing gas as a clathrate, wherein the gas clathrate or its powder is placed in a container filled with a gas body of the same type as the gas. The gas clathrate or the powder in the container is kept in a pressure equilibrium state by the gas body, and the gas clathrate can be stably stored. That is, regasification of the gas clathrate or the powder thereof can be suppressed without performing any special treatment on the gas clathrate or the powder thereof.

  (2) The gas clathrate storage method according to the second means is a method of storing a gas as a clathrate, and after molding the gas clathrate powder, the molded body is treated with the same kind of gas as the gas. It is housed and stored in a container filled with a body, and has the effect (1) described above, and can facilitate handling and increase the storage volume efficiency by molding the powder.

  (3) The gas clathrate storage method according to the third means is a method for storing gas as a clathrate, after the gas clathrate powder and / or a molded product of the powder is stored in an airtight container. The gas body of the same type as the gas is filled and stored in the hermetic container, and the effects of the above (1) and (2) can be obtained, and the filling gas pressure in the container can be easily managed. In addition, when the powder and a molded body of the same powder are stored in a container, the powder can be accommodated in the gap between the molded bodies and the storage volume efficiency can be further increased than the above, and the molded body is mixed in the powder. Therefore, the solidification phenomenon of the powder due to the weight of the powder, which may occur when only the powder is stored, can be prevented, and the lump can be easily obtained.

  (4) A gas clathrate storage method according to a fourth means is a method of storing a gas as a clathrate, wherein a gas clathrate powder and / or a molded product of the powder is the same type of gas as the gas. By storing and sealing in a container in a body atmosphere, the gas body is stored as being filled in the container, and has the effects (1), (2), and (3) above. At the same time, it is suitable when the operation of carrying in the powder and / or the molded body of the same powder into the container is a remote operation.

  (5) A gas clathrate storage method according to a fifth means is the gas clathrate storage method according to any one of (1) to (4), wherein the gas and the gas body are mainly composed of methane. The gas body has a filling pressure of atmospheric pressure or higher, and the gas clathrate can be stably stored by the filling pressure of atmospheric pressure or higher, and the storage temperature is −50 ° C. or higher. By doing so, the filling pressure can be reduced, and the pressure-resistant structure of the container can be simplified.

  (6) A gas clathrate storage method according to a sixth means is the gas clathrate storage method according to (5), wherein the gas body is a mixed gas of natural gas and propane gas. In the container, the gas clathrate can be promoted to be a type II crystal structure that can be stabilized at a lower temperature (about −20 ° C.) than the type I crystal structure.

  (7) A gas clathrate storage method according to a seventh means is the gas clathrate storage method according to any one of (1) to (4), wherein the gas and the gas body are hydrocarbon gas or 2 It is a mixed gas of hydrocarbon gases of more than one species, and various gases can be kept in a pressure equilibrium state by a gas body and gas clathrate can be stably stored.

  (8) A gas clathrate storage method according to an eighth means is the gas clathrate storage method according to any one of (1) to (4), wherein the gas and the gas body are carbon dioxide gas, hydrogen sulfide. , Halogen, rare gas, hydrogen or propane gas, and has the same effect as the above (7).

  (9) The gas clathrate storage method according to the ninth means is the gas clathrate storage method according to any one of (1) to (8), wherein the temperature is −50 to 0 ° C. under atmospheric pressure. The container is stored under an environment, and can be stored at −50 to 0 ° C. by the storage method of (1) to (8). Can be covered with refrigeration equipment.

  (10) A gas clathrate transport method according to a tenth means is a method of transporting a gas as a clathrate, wherein a gas clathrate powder and / or a molded product of the powder is the same kind of gas as the gas. It is transported in a state where it is contained in a container filled with the body, and the gas clathrate powder in the container and / or the molded body of the same powder is maintained in a pressure equilibrium state by the gas body, and the gas clathrate is stabilized. Can be transported.

  (11) The gas clathrate transport method according to the eleventh means is the gas clathrate transport method according to the above (10), wherein the gas and / or gas body is natural gas mainly composed of methane. Yes, the container is transported using means capable of maintaining a temperature environment of −50 to 0 ° C. under atmospheric pressure, and transport of −50 to 0 ° C. is possible by the transport method of (10). It can be covered with ordinary container steel and refrigeration equipment.

  (12) A gas clathrate storage method according to a twelfth aspect is the gas clathrate transport method according to (10), wherein the gas and the gas body are a hydrocarbon gas or two or more hydrocarbon gases, Or carbon dioxide, hydrogen sulfide, halogen, rare gas, hydrogen, propane gas and / or mixed gas of them, keep various gases in pressure equilibrium by gas body, and transport gas clathrate stably it can.

  (13) A gas clathrate storage container according to the thirteenth means is a container capable of storing a gas clathrate powder of natural gas mainly composed of methane gas and / or a molded body of the same powder together with natural gas, The container has a pressure-tight and air-tight structure that can withstand a gas filling pressure of atmospheric pressure or higher, and the same natural gas as the gas clathrate source gas can be stored in the container. A gas clathrate can be stably stored, and a container with high storage volume efficiency can be provided.

  (14) A gas clathrate storage container according to a fourteenth aspect is the gas clathrate storage container according to (13), wherein the gas clathrate powder and / or a molded body of the powder is carried into the container. An opening / closing lid for entering and a means for filling the natural gas are provided, and has the same effect as the above (13), and filling and filling the natural gas into the container. Pressure management can be easily performed. Moreover, as a filling means, there are a valve and a check valve provided in the container, and a gas body supply pipe may be connected to the valve for filling.

  The gas clathrate storage method according to claim 1, comprising the first means, wherein the gas is stored as a clathrate, and the gas clathrate or powder thereof is filled with a gas body of the same type as the gas. Gas clathrate regas without any special treatment on the gas clathrate by filling the container with the same gas body as the gas clathrate source gas. The gas clathrate can be stored in a cold storage environment of about 0 ° C. to −50 ° C. and in a relatively low pressure pressure resistant structure. Further, since the gas clathrate or the powder thereof is stored as it is, it can be easily used for gasification in the subsequent process.

  The gas clathrate storage method according to claim 2, comprising a second means, wherein the gas is stored as a clathrate, and after molding the gas clathrate powder, It is housed and stored in a container filled with the same type of gas body, and without any special treatment (for example, generation of an iced layer on the molded body), the gas clathrate Thus, the gas clathrate can be stored in a cold storage environment of about 0 ° C. to −50 ° C. and in a relatively low pressure pressure resistant structure. In addition, since the gas clathrate powder molded body is stored as it is, it is easy to use and handle the gasification in the subsequent process, and the storage volume ratio is more effective than the above.

  The gas clathrate storage method according to claim 3 comprising the third means, wherein the gas is stored as a clathrate, wherein the gas clathrate powder and / or a molded product of the powder is placed in an airtight container. After storing, the gas body of the same type as the gas is filled and stored in the hermetic container, and adjustment of the filling pressure of the gas body can be easily performed. Further, when the gas clathrate powder and the molded body of the powder are stored, the storage volume ratio is further improved as compared with the first and second means.

  The method for storing a gas clathrate according to claim 4 comprising the fourth means, wherein the gas is stored as a clathrate, wherein the gas clathrate powder and / or a molded product of the powder is combined with the gas. By storing and sealing in a container under the same kind of gas body atmosphere, the gas body is stored as being filled in the container, and when the gas clathrate is stored in the container, Filling can be performed, suitable for remote storage, and quick storage.

  The gas clathrate storage method according to claim 5, comprising the fifth means, wherein the gas and the gas body are mainly composed of methane in the gas clathrate storage method according to claims 1 to 4. Natural gas, which has a gas body filling pressure equal to or higher than atmospheric pressure, and is filled with a gas body of the same type as the clathrate source gas. It is possible to reduce the cost of the pressure-resistant structure of the storage container and storage equipment.

  7. The gas clathrate storage method according to claim 6, comprising a sixth means, wherein the gas body is a mixed gas of natural gas and propane gas. By the reaction action of propane gas, the crystal structure of the gas clathrate in the container becomes an in-container environment that can be easily stabilized to type II, and can be stably stored even at a storage temperature of about −20 ° C.

  The gas clathrate storage method according to claim 7, comprising the seventh means, wherein the gas and the gas body are hydrocarbon gas in the gas clathrate storage method according to any one of claims 1 to 4. Or it is a mixed gas of 2 or more types of hydrocarbon gas.

The gas clathrate storage method according to claim 8 comprising the eighth means, wherein the gas and the gas body are carbon dioxide, the gas clathrate storage method according to any one of claims 1 to 4. Those which are hydrogen sulfide, halogen, rare gas, hydrogen or propane gas.
According to the seventh and eighth means, various gases can be stably stored in the form of gas clathrate.

  The gas clathrate storage method according to claim 9 comprising the ninth means, wherein the gas clathrate storage method according to any one of claims 1 to 8 is -50 to 0 ° C under atmospheric pressure. The container is stored under the temperature environment, and the gas clathrate can be stored by utilizing a general-purpose refrigerated storage facility, and the cost of the storage facility can be reduced.

  The method for transporting a gas clathrate according to claim 10 comprising the tenth means, wherein the gas is transported as a clathrate, wherein the gas clathrate powder and / or a molded product of the powder is used as the gas. It is transported in a state of being accommodated in a container filled with the same kind of gas body, and the gas clathrate during transportation can be stabilized, and transportation with general-purpose refrigeration equipment is possible.

  The gas clathrate storage method according to claim 11, comprising the eleventh means, wherein the gas and / or gas body comprises methane as a main component in the gas clathrate transport method according to claim 10. The container is a natural gas and transports the container using a means capable of maintaining a temperature environment of −50 to 0 ° C. under atmospheric pressure. The transport means (ship or Trucks, etc.) can be used, and peripheral equipment costs can be reduced.

  The gas clathrate storage method according to claim 12, comprising a twelfth means, wherein the gas and the gas body are hydrocarbon gas or two or more hydrocarbons. Gas or carbon dioxide gas, hydrogen sulfide, halogen, rare gas, hydrogen, propane gas and / or mixed gas thereof, which uses a special, high pressure pressure resistant container that stably stabilizes various gas clathrates Can be transported without

  The gas clathrate storage container according to claim 13, which comprises thirteenth means, is a container capable of storing a gas clathrate powder of natural gas mainly composed of methane gas and / or a molded body of the powder together with natural gas. The container has a pressure-tight and airtight structure that can withstand a gas filling pressure of atmospheric pressure or higher, and can stably store and store methane gas clathrate. In addition, a pressure vessel of the same filling pressure as the left can be manufactured at low cost.

  The gas clathrate storage container according to claim 14, comprising the fourteenth means, wherein the gas clathrate storage container according to claim 13 carries the gas clathrate powder and / or a molded body of the powder into the container. An opening / closing lid for entering and means for filling the natural gas are provided, and the above-described effects can be obtained, and the filling of the natural gas and the filling pressure management can be easily performed.

  The gas clathrate storage method, transport method, and gas clathrate container according to the present invention will be described with reference to FIGS. FIG. 1 is a front view of a gas clathrate storage container, FIG. 2 is a perspective view of a gas clathrate transport container for loading a container, and FIG. 3 is a side view of a gas clathrate transport ship.

The case of storing and storing the gas clathrate or the powder and the pressure-molded body of the powder will be described with an example using the gas clathrate storage container 1 (hereinafter referred to as a container) shown in FIG. . A gas clathrate or a powder thereof and a pressure molded body B of the same powder (hereinafter referred to as a mixture of a gas clathrate or a powder thereof and a pressure molded body) in a bottomed cylindrical (drum-shaped) container body 2 A gas filling means comprising a stop valve, a gas injection, and a pressure reducing nozzle after the opening / closing lid 3 is closed and the opening / closing lid 3 is hermetically fixed to the flange 6 of the container body 2 by the bolt 7. 5, the container 1 is filled with a gas body until the filling pressure reaches a predetermined pressure (above atmospheric pressure, for example, 1 to 2.5 kgf / cm ² ). The entire container 1 is covered with a heat insulating layer 4.

  In this case, the gas body to be filled is of the same type as the gas clathrate source gas, so that a pressure equilibrium state with the gas clathrate is maintained in the container 1 (to stabilize the gas clathrate). Is most appropriate for. The gas body to be filled may be a mixed gas of a raw material gas and a gas different from the raw material gas. However, since the filling pressure of the raw material gas for maintaining the pressure equilibrium state is fixed, another kind of gas is used. The charging pressure increases by the amount of charged.

  In this embodiment, the gas to be stored, transported and stored (and the gas body filled in the container) is a hydrocarbon gas or a mixed gas of two or more kinds of hydrocarbon gases. Examples of the hydrocarbon gas include hydrocarbon gas such as natural gas mainly composed of methane, pure methane, ethane, ethylene, propane, propylene, and butane. Further, the present invention can be similarly applied to storage and transportation of carbon dioxide gas, halogen such as hydrogen sulfide and chlorine, rare gas such as argon, and hydrogen.

  Further, in the chamber filled with the gas body, after the gas clathrate powder and the pressure-molded body A of the same powder are stored in the container body 2, the gas body is contained in the container 1 by sealing the open / close lid 3. Can be filled. When the container 1 is transported, it may be transported by a refrigeration trailer or the like in a cold state at 0 ° C. or less under atmospheric pressure.

  Next, the case where the gas clathrate or the powder thereof and the pressure-molded body of the powder are stored, stored and transported will be described with reference to an example using the gas clathrate transport container 1A shown in FIG. The gas clathrate transport container shown in FIG. 2 has a flange-structured open / close lid 3, a stop valve 5A provided in the transport container 1A, gas injection means 5 composed of a gas injection and decompression nozzle, and the open / close lid 3 as a transport container. The bolt 7 for fixing to 1A, the outer periphery of 1 A of transport containers, the steel frame 9 provided integrally, and the safety valve 10 provided in 1 A of transport containers are comprised.

Thus, when the gas clathrate or the powder thereof and the pressure-molded body of the same powder are stored, stored and transported, the transport container 1A is set upright, the open / close lid 3 is opened, and the gas clathrate powder from above. Then, after the pressure-molded body of the same powder is carried in, the opening / closing lid 3 is closed, and the gas body is filled with the same or the same gas body as the gas raw material of the carried gas clathrate from the gas filling means 5 ( Filling pressure 2 kgf / cm ² ). Next, the transport preparation is completed if the transport container 1A is stored in the refrigerated container of the trailer by crane equipment or the like (not shown). Note that the outer shape of the frame 9 is formed in a rectangular shape that can be stably and perfectly fit in the freezing container of the trailer.

  Next, the case where the gas clathrate or the powder thereof and the pressure-molded body of the powder are stored, stored, and transported will be described using an example using the gas clathrate transport ship 1B shown in FIG. The gas clathrate transport ship shown in FIG. 3 includes a gas clathrate transport / storage tank 1C, gas filling means 5 and a safety valve 10 provided in each storage tank 1C.

  Thus, when storing and transporting the gas clathrate or the powder thereof and the pressure-molded body of the same powder, the gas clathrate powder and the pressure-molded body of the same powder in each storage tank 1C of the transport ship 1B. If the same or the same gas body as the gas raw material of the gas clathrate carried in is filled in each storage tank 1C from the gas filling means 5, the preparation for transportation is completed.

  According to the embodiment, when the gas clathrate is, for example, methane clathrate, the powder is accommodated in a container, or the methane clathrate is molded and then the molded body is accommodated in the container. Can be stored and transported at a high content and atmospheric pressure. In particular, when the gas is natural gas, it can be stored and transported at a high content and at a pressure of −50 to 0 ° C. under atmospheric pressure.

  Natural gas is mainly composed of methane, but also contains ethane, propane, n-butane, isobutane, and the like, so that natural gas clathrate tends to have a more stable structure (type II) than pure methane clathrate. Furthermore, by filling the gas body as in the above embodiment, the natural gas clathrate can be further stabilized, and the cold storage temperature can be stored without decomposition until it reaches about 0 ° C. If it becomes -50 degrees C or less, a general steel material will become unusable and a refrigerator will also become a special thing, Therefore The thing of a present Example is economically advantageous from both sides of an installation cost and an operating cost.

  The gas clathrate itself may be in that state, such as natural methane clathrate, or may be a separately synthesized clathrate. In the above embodiment, methane, which is a main component of natural gas, has been described as an example. However, the present invention can be similarly applied to other gases.

  In each of the above embodiments, the gas clathrate, the gas clathrate powder and the pressure-molded body A of the same powder, or the powder or the pressure-molded body B are left as they are (as in the conventional ice coating layer). The gas clathrate powder or the like may be depressurized and opened at the storage environment temperature, and the release and gas extraction operations become much easier.

  The storage (transportation, storage) container in the above embodiment can accommodate and seal the gas clathrate, the gas clathrate powder or a molded body thereof, and the gas clathrate powder or the molded body under the environmental temperature during transportation and storage. Any structure that can withstand the pressure that is balanced between the gas bodies may be used. Moreover, the container which accommodated the gas clathrate powder or its molding should just be conveyed by transport means, such as a motor vehicle, a railway, and a ship.

  According to each of the above embodiments, the decomposition of the clathrate of methane clathrate and other various gases can be effectively prevented or suppressed, and can be safely stored and transported. Further, since the gas can be rapidly released and taken out only by raising the temperature of the gas clathrate, it can be easily used for the use as the gas itself.

It is a front view of the gas clathrate storage container which concerns on Example 1 of this invention. It is a perspective view of the gas clathrate transport container for container mounting concerning Example 2 of the present invention. It is a side view of the gas clathrate transport ship which concerns on Example 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gas clathrate storage container 2 Container main body 3 Opening / closing lid 4 Heat insulation layer 5 Gas filling means

Claims (14)

  A method for storing a gas clathrate, comprising storing the gas clathrate or powder thereof in a container filled with a gas body of the same type as the gas.   A method of storing a gas as a clathrate, wherein after molding a gas clathrate powder, the molded body is housed and stored in a container filled with a gas body of the same type as the gas. Gas clathrate storage method.   A method for storing gas as a clathrate, wherein a gas clathrate powder and / or a molded body of the same powder is stored in an airtight container, and then the same gas body as the gas is filled in the airtight container. A method for storing a gas clathrate, comprising storing the gas clathrate.   A method for storing gas as a clathrate, wherein a gas clathrate powder and / or a molded body of the same powder is contained and sealed in a container in an atmosphere of the same gas body as the gas, A gas clathrate storage method, wherein the gas body is stored in a state of being filled in the container.   The gas class according to any one of claims 1 to 4, wherein the gas and the gas body are natural gas mainly composed of methane, and a filling pressure of the gas body is equal to or higher than an atmospheric pressure. Rate storage method.   6. The gas clathrate storage method according to claim 5, wherein the gas body is a mixed gas of natural gas and propane gas.   The gas clathrate storage method according to any one of claims 1 to 4, wherein the gas and the gas body are a hydrocarbon gas or a mixed gas of two or more hydrocarbon gases.   The gas clathrate storage method according to any one of claims 1 to 4, wherein the gas and the gas body are carbon dioxide, hydrogen sulfide, halogen, rare gas, hydrogen or propane gas.   The gas clathrate storage method according to any one of claims 1 to 8, wherein the container is stored under a temperature environment of -50 to 0 ° C under atmospheric pressure. Method.   A method for transporting a gas as a clathrate, characterized in that a gas clathrate powder and / or a molded body of the same powder is transported in a state of being contained in a container filled with the same gas body as the gas. How to transport gas clathrate.   The gas and / or gas body is a natural gas mainly composed of methane, and the container is transported using means capable of maintaining a temperature environment of −50 to 0 ° C. under atmospheric pressure. Item 11. A method for transporting a gas clathrate according to Item 10.   The gas and the gas body are hydrocarbon gas or two or more hydrocarbon gases, or carbon dioxide gas, hydrogen sulfide, halogen, rare gas, hydrogen, propane gas and / or a mixed gas thereof. 10. A method for transporting a gas clathrate according to 10.   Natural gas gas clathrate powder mainly composed of methane gas and / or a container that can be molded with the natural gas together with natural gas, and the container can withstand a gas filling pressure higher than atmospheric pressure. A gas clathrate container characterized by being.   An opening / closing lid for carrying the gas clathrate powder and / or a molded body of the powder into and out of the container and means for filling the natural gas are provided in the container. The gas clathrate storage container as described.

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