JP2006265404A - Gas hydrate generator and generation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas hydrate generator capable of safely and continuously taking out gas hydrate slurry of almost uniform slurry content from a reaction vessel. <P>SOLUTION: The gas hydrate generator has a constitution of setting the inside of a reaction vessel 1 at a predetermined temperature and pressure, generating gas hydrate 22 by bringing a raw material gas 18 into contact with water 16 in the reaction vessel, accumulating the generated gas hydrate on the water surface of the reaction vessel, and taking out the gas hydrate remaining on the water surface, outside the reaction vessel through a means 14, wherein a helical cylinder 32 having a helical path 30 linked to a vessel wall 3 from the center of the reaction vessel is set to extend from above water surface to underwater at the water surface part where the gas hydrate remains, and a takeout hole 12 of a takeout means is set at a position communicated with the helical path at the vessel wall 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  In the present invention, the inside of a reaction vessel is set to a predetermined temperature and pressure, and gas hydrate is generated by contact of raw material gas and water in the reaction vessel, and the generated gas hydrate is on the water surface in the reaction vessel. The present invention relates to a gas hydrate generating apparatus and a generating method in which gas hydrate collected on the water surface is extracted out of a reaction vessel by extraction means.

  In gas hydrate, gas molecules such as hydrocarbons such as methane, ethane, propane, and butane, which are natural gas components, and carbon dioxide are taken into the interior of the three-dimensional structure formed by combining water molecules. It is a general term for clathrate hydrates (hydrates) formed in this way. That is, the gas hydrate is an ice-like solid substance composed of source gas molecules and water molecules, and is a stable clathrate compound in which source gas molecules are included inside a three-dimensional cage structure formed by water molecules. It is a kind. This gas hydrate has a relatively large gas storage capacity, and has characteristic properties such as large generation / decomposition energy and selectivity of hydrated gas. For example, transportation and storage of natural gas, etc. Various applications such as means, heat storage systems, actuators, and separation and recovery of specific component gases are possible, and research is actively conducted.

  Gas hydrate is usually generated under high pressure and low temperature conditions. The following methods are well known as generation methods. By spraying water cooled from the upper part of the reaction vessel filled with the raw material gas at a high pressure, when the water droplets fall in the raw material gas, gas hydrate is generated on the surface of the water droplets. A so-called “bubbling method” or the like in which a gas hydrate is generated on the surface of a bubble when the bubble of the source gas rises in the water by introducing the raw material gas as bubbles in the water (bubbling).

  As an example of the former gas hydrate generation apparatus using the spray method, there is an apparatus described in Patent Document 1 (Japanese Patent Laid-Open No. 2000-264852). The gas hydrate produced by contacting the raw material gas and spray water in the reaction vessel generally has a specific gravity smaller than that of water, and fine bubbles adhere to the hydrate. Therefore, the gas hydrate floats on the water surface in the reaction vessel. A hydrate layer is formed. By continuing the contact reaction, the gas hydrate gradually accumulates on the surface of the water and is concentrated to become a wet shrink slurry. The concentrated slurry of gas hydrate is extracted by an extraction device in which an extraction port is arranged in the container wall near the water surface.

  In addition, as shown in FIGS. 5 and 6, the gas hydrate generating apparatus using the bubbling method also collects the gas hydrate 10 generated below the water surface in the reaction vessel 1 on the water surface, and stores it in a container near the water surface. It is the same as the spray system in that it is extracted by an extraction device 14 in which an extraction port 12 is arranged on the wall. In the figure, reference numeral 16 indicates stored water.

JP 2000-264852 A

  In the conventional gas hydrate generator, the concentrated slurry of the gas hydrate 10 floating on the water surface in the reaction vessel 1 is removed from the reaction vessel 1 by an extraction device 14 in which an extraction port 12 is arranged on the vessel wall near the water surface. Since the concentrated slurry near the extraction port 12 is extracted, the water 16 increases thereafter, and the concentration of the extracted gas hydrate slurry is not constant and varies. The gas hydrate slurry extracted out of the reaction vessel is usually further applied to a concentrator in the next step, and there is a desirable slurry concentration range when applied to the concentrator. If the slurry concentration taken out from the reaction vessel is not constant and varies, there is a problem that the slurry concentration falls outside the desirable slurry concentration range of the next step. That is, the conventional structure has a problem that the concentrated slurry cannot be stably and continuously extracted from the reaction vessel.

  An object of the present invention is to provide a gas hydrate production apparatus and production method capable of stably and continuously extracting a gas hydrate slurry having a substantially uniform slurry concentration from the reaction vessel.

  In order to achieve the above object, the gas hydrate generator according to the first aspect of the present invention is configured such that the inside of a reaction vessel is set to a predetermined temperature and pressure, and gas hydrate is brought into contact with the raw material gas and water in the reaction vessel. The generated gas hydrate is collected on the water surface in the reaction vessel, and the gas hydrate accumulated on the water surface is extracted from the reaction vessel by the extraction means. A helical cylinder having a spiral path connected from the center of the reaction vessel to the vessel wall is provided on the water surface portion where the generated gas hydrate accumulates, and extends from the water surface to the water surface, The extraction opening is provided at a position communicating with the spiral path in the container wall.

  According to the present invention, a spiral cylinder having a spiral path is provided on the water surface portion where the generated gas hydrate accumulates so as to straddle from above the water surface to below the water surface, and the extraction force of the extraction means is provided from the extraction port to the spiral cylinder. Since it is configured to be transmitted in a closed state to the spiral path of the body, the gas hydrate in the spiral cylinder can be moved along the spiral path to be stably and continuously extracted out of the reaction vessel. it can.

The gas hydrate generator according to the second aspect of the present invention, in the first aspect, is provided with swirl flow forming means for generating a swirl flow in the same direction as the spiral path in the water in the reaction vessel. It is characterized by.
According to the present invention, the swirl flow formed by the swirl flow forming means contributes to the flow velocity in the spiral path, and therefore, the gas hydrate on the water surface is not subjected to centrifugal separation, but is extracted from the spiral path. The action of smoothly moving toward the mouth is expressed. Therefore, in addition to the operational effects of the first aspect, the gas hydrate in the spiral cylinder can be moved along the spiral path and extracted out of the reaction vessel more stably and continuously. .

  A gas hydrate generator according to a third aspect of the present invention is a spray-type gas hydrate generator according to the first aspect, wherein the contact between the raw material gas and water is performed by spraying water into the reaction vessel. The gas hydrate in the spiral path is moved and extracted along the spiral path by the suction force of the suction means included in the extraction means.

  INDUSTRIAL APPLICABILITY The present invention is particularly effective for a spray-type gas hydrate generator that does not have a swirl flow forming means such as a stirrer. Since the suction force of the suction means such as a pump included in the extraction means is transmitted from the extraction port to the spiral path of the spiral cylindrical body, the gas hydrate moves along the spiral path and is extracted.

In the gas hydrate production method according to the fourth aspect of the present invention, the inside of the reaction vessel is set to a predetermined temperature and pressure, and the raw material gas is brought into contact with water in the reaction vessel to produce gas hydrate. The gas hydrate is accumulated on the water surface in the reaction vessel, and the gas hydrate production method for producing the gas hydrate accumulated on the water surface by extracting the gas hydrate from the reaction vessel by extracting means, wherein the gas hydrate is accumulated. A spiral cylinder having a spiral path connected to the vessel wall from the central part of the reaction vessel on the water surface portion is provided by using the spiral cylinder provided so as to extend from above the water surface to below the water surface. The gas hydrate in the cylindrical body is moved along the spiral path and extracted out of the reaction vessel.
According to the present invention, the same effect as the first aspect can be obtained.

  According to the present invention, a gas hydrate slurry having a substantially uniform slurry concentration can be stably and continuously extracted outside the reaction vessel along the spiral path of the spiral cylindrical body.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Example 1]
FIG. 1 is a schematic cross-sectional view showing an embodiment of a bubbling-type natural gas hydrate generator according to the present invention, FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1, and FIG. It is a perspective view of a notch.

  A sparger 20 is provided which constitutes a raw material gas supply means for supplying a raw material gas 18 made of natural gas into the water 16 in the reaction vessel 1 as bubbles. The sparger 20 is communicated with a gas supply source (not shown) and supplies the raw material gas 18 into the water 16 with a controlled injection amount. The inside of the reaction vessel 1 is adjusted to a predetermined temperature and pressure by a known method. In this embodiment, the temperature is 1 ° C. to 5 ° C., the pressure is 4 MPa to 8 MPa, preferably the temperature is 2 ° C. to 4 ° C., and the pressure is 5 MPa to 6 MPa. Under this temperature and pressure, the bubbles of the raw material gas 18 and the water 16 come into contact with each other so that a natural gas hydrate 22 is generated.

  In FIG. 1, reference numeral 24 denotes a rotary blade, and the rotary blade 24 is attached to a drive device 28 via a rotary shaft 26 disposed at the center of the reaction vessel 1. By rotating the rotary blade 24, the bubbles of the raw material gas 18 supplied from the sparger 20 into the water 16 are further miniaturized to increase the contact reactivity with water. At the same time, the natural gas hydrate 22 generated by forming a swirling flow in the water 16 in the reaction vessel 1 is slurried. FIG. 1 shows a state where the slurryed natural gas hydrate 22 floats on the water surface to become a concentrated slurry.

  In the present invention, a spiral cylindrical body 32 having a spiral path 30 connected from the center of the reaction vessel 1 to the vessel wall 3 is formed on the water surface portion where the generated natural gas hydrate 22 is accumulated from above the water surface to below the water surface. It is provided to straddle. The extraction port 12 of the extraction device 14 is provided at a position communicating with the spiral path 30 in the container wall 3. As shown in FIG. 2 and FIG. 3, the outermost peripheral end 34 is fixed to the container wall 3 of the reaction vessel 1, and the helical cylinder 32 is held at that position. With the above configuration, the extraction force of the extraction device 14 is transmitted from the extraction port 12 to the spiral path 30 of the spiral cylindrical body 32 in a closed state.

The upper and lower ends of the spiral cylindrical body 32 are opened as shown in FIG. It is appropriate to change the depth of submergence of the spiral body 32 from the water surface, that is, the length below the water surface, in accordance with the amount of the natural gas hydrate 22 to be produced. This can be achieved by setting the water level to 1/5 to 1/2 of the water level from the bottom (when the rotary blade 24 is 1/3 of the water level). The space between the spirals is configured to be narrow at the center so that the flow velocity in the spiral path 30 is substantially constant over the entire length, and gradually becomes wider as the container wall 3 is approached.
As described above, the concentrated natural gas hydrate slurry near the water surface can be extracted out of the reaction vessel 1 at a substantially uniform concentration.

  In the present embodiment, a swirling flow forming device 36 is provided that generates a swirling flow in the same direction as the spiral path 30 in the water 16 in the reaction vessel 1. The swirl flow forming device 36 is configured so that the rotary blade 24 also serves. In FIG. 1, reference numeral 38 denotes a water supply port, and reference numeral 40 denotes a suction pump.

Next, the operation of the first embodiment will be described.
According to the present embodiment, the spiral cylindrical body 32 having the spiral path 30 is provided on the water surface portion where the generated natural gas hydrate 22 is accumulated so as to straddle the water surface from below the water surface, and the extraction force of the extraction device 14 is increased. Since it is configured to be transmitted from the outlet 12 to the spiral path 30 of the spiral cylinder 32 in a closed state, the natural gas hydrate 22 in the spiral cylinder 32 is moved along the spiral path 30. Thus, it can be extracted stably and continuously outside the reaction vessel 1.

  Further, when the swirl flow is formed by the swirl flow forming device 36, the swirl flow is generated in the water 16 in the reaction vessel 1 in the same direction as the spiral path 30. This contributes to the natural gas hydrate 22 on the water surface, not the centrifugal separation action, but the action of smoothly moving the inside of the spiral path 30 toward the extraction port 12. Accordingly, the natural gas hydrate 22 in the spiral cylindrical body 32 can be moved along the spiral path 30 and extracted out of the reaction vessel 1 more stably and continuously.

[Example 2]
FIG. 4 is a schematic sectional view showing an embodiment of a spray-type natural gas hydrate generating apparatus according to the present invention. About the same structure as the said Example 1, the same code | symbol is attached | subjected to the same part and the description is abbreviate | omitted.

  In the gas hydrate generator according to the second embodiment, the contact between the raw material gas 18 supplied from the gas nozzle 45 provided at the upper part of the reaction vessel 1 and the water 16 causes water 16 to be sprinkled from the nozzle 50 into the reaction vessel 1. This is a spray-type gas hydrate generating apparatus. The water 16 sprayed from the nozzle 50 is sprinkled after the water 16 stored in the reaction vessel 1 is taken out from the outlet 52 and cooled by the heat exchanger 54. In FIG. 4, reference numeral 56 denotes a water circulation pump. And it is comprised so that the natural gas hydrate 22 in the said spiral path 30 may move along the spiral path 30 with the suction | attraction force of the suction pump 40 which the extraction device 14 has, without making a swirl flow. Yes.

  In the second embodiment, the suction force of the pump 40 of the extraction device 14 is transmitted from the extraction port 12 to the spiral path 30 of the spiral cylindrical body 32, so that the natural gas hydrate 22 is transferred to the spiral path 30. Moved along and extracted. As described above, the present invention is particularly effective for a spray-type gas hydrate generating apparatus in which the stirring means such as the rotary blade 24 or the swirl flow forming device 36 is not installed.

  INDUSTRIAL APPLICABILITY The present invention can be used for a gas hydrate generating apparatus and a generating method for generating gas hydrate by bringing a raw material gas into contact with water under a predetermined temperature and pressure condition in a reaction vessel.

It is a schematic sectional drawing which shows one Example of the bubbling type natural gas hydrate production | generation apparatus which concerns on this invention. It is the II-II sectional view taken on the line of FIG. It is a perspective view of a notch showing a spiral cylinder. It is a schematic sectional drawing which shows one Example of the natural gas hydrate production | generation apparatus of the spray system which concerns on this invention. It is a schematic sectional drawing which shows one Example of the conventional natural gas hydrate production | generation apparatus of a bubbling system. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reaction container 3 Container wall part 12 Extraction port 14 Extraction apparatus 16 Water 18 Raw material gas 22 Natural gas hydrate 24 Rotary blade 30 Spiral path 32 Spiral cylindrical body 34 Outermost peripheral edge part 36 Swirling flow formation apparatus 40 Suction pump

Claims (4)

The inside of the reaction vessel is set to a predetermined temperature and pressure, and gas hydrate is generated in the reaction vessel by contact with the raw material gas and water, and the generated gas hydrate accumulates on the water surface in the reaction vessel, and A gas hydrate generator configured to be extracted from the reaction vessel by extraction means, the gas hydrate accumulated on the water surface,
In the water surface portion where the generated gas hydrate accumulates, a spiral cylinder having a spiral path connected from the center of the reaction vessel to the vessel wall is provided so as to straddle from above the water surface to below the water surface,
The gas hydrate generator according to claim 1, wherein an extraction port of the extraction means is provided at a position communicating with the spiral path in the container wall.   2. The gas hydrate generator according to claim 1, further comprising a swirl forming means for generating swirl in the same direction as the spiral path in the water in the reaction vessel.   2. The spray-type gas hydrate generating device according to claim 1, wherein the contact between the source gas and water is performed by sprinkling water into the reaction vessel, and the inside of the spiral path is caused by the suction force of the suction means included in the extraction means. A gas hydrate generating apparatus characterized in that the gas hydrate moves along a spiral path and is extracted. The inside of the reaction vessel is set to a predetermined temperature and pressure, and the raw material gas and water are brought into contact with each other in the reaction vessel to produce gas hydrate. The produced gas hydrate is accumulated on the water surface in the reaction vessel, and A gas hydrate production method for producing gas hydrate accumulated on the water surface by extracting the gas hydrate from the reaction vessel with an extraction means,
Using the helical cylinder provided in such a manner that a helical cylinder having a spiral path connected from the central part of the reaction vessel to the vessel wall part in the water surface part where the gas hydrate is accumulated, straddles the water surface from below the water surface, A gas hydrate generating method, wherein the gas hydrate in the spiral cylinder is moved along the spiral path by the extracting means and extracted out of the reaction vessel.

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