WO2007110919A1 - Fluidized-bed gas hydrate generator and method of generating gas hydrate - Google Patents

Abstract

A fluidized-bed gas hydrate generator (3) which comprises: a vertical vessel having an introduction opening (30) through which a powdery or granular gas hydrate containing unreacted water is introduced; a dispersion plate disposed between the introduction opening (30) and the bottom of the vertical vessel; a feed gas circulation line (42) having a circulation gas blower (32) for sucking a feed gas in the vertical vessel through a suction opening formed in an upper part of the vertical vessel and circulating it to a lower part of the vertical vessel; and a discharger (38) for discharging the gas hydrate present above the dispersion plate. Due to the constitution, the gas hydrate is fluidized and the gas/liquid contact efficiency is heightened to efficiently react the unreacted water with the feed gas. As a result, the conversion of unreacted water into a gas hydrate can be effectively heightened.

Description

 Specification

 Fluidized bed gas hydrate generator and gas hydrate generation method

 [0001] The present invention relates to fluidized bed gas hydrate generation in which unreacted water contained in a gas hydrate generated by reacting a raw material gas and water is reacted with the raw material gas to increase the hydrate yield rate. The present invention relates to an apparatus and a gas hydrate generation method.

 Background art

 [0002] Gas hydrate is a solid hydrate that has a structure in which gas is taken into a cage formed by water molecules, and is relatively stable under atmospheric pressure of about 20 ° C. Research is underway to use it as a means of transporting and storing natural gas instead of (LNG).

 [0003] In general, gas and idrate are produced, for example, by reacting a raw material gas such as natural gas, methane gas, and carbon dioxide with water in a low-temperature and high-pressure vessel. Since the gas hydrate produced in this way contains a large amount of unreacted water, it is necessary to separate the water and purify the product gas hydrate.

 [0004] According to the hydrate manufacturing method described in Patent Document 1, a raw material gas is supplied into a production vessel, and low-temperature circulating water is sprayed (sprayed) into the raw material gas in the production vessel. A so-called spray-type hydrate generator for generating an idrate is employed. In such a hydrate generator, the hydrate floating near the liquid level in the production vessel is extracted as a slurry together with water, and led to a double-structure screw single press type dehydrator having a meshed inner cylinder! Make it physically dehydrated! Since this screw press type dehydrator has a limited dehydration rate, it is further led to a twin-screw type dehydrator to dehydrate unreacted water and raw material gas contained in the gas hydrate by a hydration reaction. A product gas hydrate with little unreacted water is obtained. Patent Document 2 also describes dehydration by a similar process.

[0005] However, the gas hydrate production plant described in Patent Documents 1 and 2 has a problem that the reducing power of unreacted water contained in the product gas and idrate is not always sufficient. That is, in the hydration dehydrator of the twin screw type dehydrator, The unreacted water contained in the rate and the raw material gas are hydrated to achieve a gas hydration of unreacted water. However, there is a limit to improving the gas-liquid contact efficiency only with the stirring action of the screw. The gas hydrate ratio of the reaction water cannot be sufficiently increased.

 [0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-55675

 Patent Document 2: Japanese Patent Laid-Open No. 2003-64385

 Disclosure of the invention

 [0007] An object of the present invention is to effectively increase the gas hydrate yield rate of unreacted water in hydration dehydration.

 [0008] In order to solve the above problems, a fluidized bed gas hydrate generator of the present invention includes a vertical container having an inlet into which a granular gas hydrate containing unreacted water is introduced, an inlet and a vertical A circulating gas projector that sucks the source gas in the vertical container and circulates it in the lower part of the vertical container, such as the dispersion plate provided between the bottom of the mold container and the suction roller provided at the upper part of the vertical container And a discharger for discharging the gas hydrate above the dispersion plate.

 That is, when a granular gas hydrate containing unreacted water is introduced into a fluidized bed gas hydrate generator and deposited on the dispersion plate, the raw material is passed through the dispersion plate from the lower part of the vertical container. Since the gas is ejected, the gas hydrate can be fluidized. This fluidized bed reaction can improve the gas-liquid contact efficiency and allow the unreacted water and the raw material gas to react efficiently. As a result, the gas and idle rate can be effectively increased.

 In this case, it is desirable to provide a cooler for cooling the source gas in the source gas circulation flow path.

 In other words, since the hydration reaction is generally accompanied by heat generation, the temperature in the vertical container may rise and the reaction efficiency between the unreacted water and the raw material gas may decrease. The source gas circulated by the circulating gas process can be cooled to a temperature suitable for the hydration reaction, and the gas hydrate yield rate can be effectively increased.

[0012] Further, the load amount of the discharger is detected, and the amount of the raw material gas circulated by the circulating gas blower, the temperature of the raw material gas, and the discharge amount of the discharger are set so that the detected load amount falls within the set range. It is desirable to provide control means for controlling at least one of the quantities. [0013] The gas hydrate concentration at which the fluidized bed gas hydrate generator power is also discharged correlates with the load of the discharger as shown in FIG. In other words, in a granular gas hydrate with relatively little water after hydration and dehydration, if the amount of unreacted water decreases, that is, the gas hydrate concentration of unreacted water increases, Improves the load on the discharger. Therefore, the load of the discharger, such as the torque or current of the drive motor of the discharger, is detected, and the amount of raw material gas, the temperature of the raw material gas, Control at least one of the quantities. That is, by controlling the fluidized bed reaction and controlling the residence time of the fluidized bed reaction, the gas hydrate concentration rate of unreacted water can be controlled, and as a result, the gas hydrate concentration can be controlled.

 [0014] Furthermore, it is desirable to provide a cyclone for collecting gas hydrate contained in the source gas in the source gas circulation passage.

[0015] According to this, since the fine gas hydrate accompanying the source gas to be circulated in the fluidized bed gas hydrate generator can be effectively separated and collected by the cyclone, it has an adverse effect on the equipment constituting the circulating gas system. Can be reduced.

[0016] By the way, if there is a finer gas hydrate that cannot be collected by the cyclone, it will adhere to the inside of the cooler of the raw material gas for a long time, leading to a decrease in the amount of heat transfer, and the circulation gas blower If attached to the blade, it may cause damage to the blade.

 [0017] Therefore, it is preferable to provide a collector that collects finer gas and idrate contained in the source gas from which the cyclone force is also discharged.

[0018] Here, the collector for collecting the fine gas hydrate includes two series of alternately switchable filters for filtering the fine gas hydrate and a heating means for heating the filter. Can be configured. Thus, even if the filter is clogged with gas or idrate, the raw material gas circulation device can be continuously operated by switching the filter. A filter clogged with gas hydrate is heated by a heating means to bring the gas hydrate to a decomposition temperature (for example, 5 ° C or higher), so that the gas hydrate is mixed with the original raw material gas and water. It can be decomposed to eliminate clogging. Here, a drain nozzle and purge gas line are usually installed to remove the decomposed water. [0019] Since the clogging can also be eliminated by reducing the pressure in the filter to a pressure at which the fine gas hydrate decomposes, the pressure of the raw material gas in the filter is lowered to the set pressure instead of the heating means. It may be equipped with a decompression means.

 [0020] Further, the collector includes a discharge electrode charged to a fine gas hydrate, a collection electrode to which a voltage having a polarity opposite to the charge of the gas hydrate charged by the discharge electrode is applied, It is possible to provide an electrostatic collector having means for removing the gas hydrate collected by the electrode also from the collecting electrode force. In addition, the gas hydrate collected by the collecting electrode can be peeled and dropped by mechanical vibrations, or the collecting electrode can be charged with a voltage having the same polarity as the gas hydrate and charged by electrostatic repulsion. Can be peeled and dropped. Alternatively, the collecting electrode can be heated to decompose the collected gas hydrate to separate and recover water.

 Brief Description of Drawings

 FIG. 1 is an overall configuration diagram of a hydrate production plant according to an embodiment to which a fluidized bed gas hydrate generator according to an embodiment of the present invention is applied.

 FIG. 2 is a graph showing the relationship between the rotational torque of a screw conveyor and the NGH concentration in a fluidized bed gas hydrate generator.

 FIG. 3 is a configuration diagram of a fluidized bed gas hydrate generator according to another embodiment of the present invention.

 4 is a configuration diagram of an embodiment of the NGH collector of the embodiment of FIG.

 FIG. 5 is a configuration diagram of another embodiment of the NGH collector of the embodiment of FIG.

 BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an overall configuration diagram of a hydrate production plant to which a fluidized bed gas hydrate generator of the present invention is applied. Although the present embodiment shows a plant for producing a hydrate of natural gas (hereinafter abbreviated as NGH), the present invention is not limited to natural gas, but other raw material gases such as methane gas, carbon dioxide gas, and the like. Applicable to rate production.

[0023] As shown in FIG. 1, the hydrate production plant of the present embodiment includes a generator 1 that generates NGH slurry, and NGH having a high concentration by separating moisture from the NGH slurry generated by the generator 1. The generated dehydration tower 2, and unreacted water contained in the NGH dehydrated in the dehydration tower 2 react with natural gas to increase the NGH concentration to the product level. It is composed of a generator 3 and a hopper 4 for storing the product NGH. The generator 1, the dehydration tower 2, the fluidized bed gas hydrate generator 3 and the hopper 4 are all maintained at a predetermined high pressure (for example, 3 to: LOMPa).

 [0024] The generator 1 is formed of a cylindrical container, and is supplied with a certain amount of high-pressure raw material gas (natural gas) and high-pressure water from a supply device (not shown), and is introduced into the generator 1. Natural gas and water react under low temperature conditions (eg, 1-5 ° C) to produce NGH. The generator 1 is provided with a stirrer 11 for stirring water and a circulating gas blower 12 for extracting natural gas. The discharge port of the circulating gas blower 12 is connected to a nozzle 13 disposed at the bottom of the container through a flow control valve 14 equipped with a flow meter. Since the generation of NGH involves heat generation, a circulating slurry pump 15 is connected to the bottom of the vessel to extract NGH slurry containing NGH, and a flow rate control valve 17 equipped with a slurry density meter 19 and slurry flow meter 17. , Cooler 16 and thermometer 18 to return to the upper part of the container, and control the amount of refrigerant in cooler 16 according to the detected value of thermometer 18 to set the temperature in generator 1 to the set temperature. Make sure to hold it on! / In addition, depending on the concentration of NGH in the NGH slurry, fluidity may deteriorate and transfer may become difficult, and problems may occur in the dewatering process on the downstream side. (For example, about 20% by weight) By controlling at least one of the circulating gas volume, circulating slurry temperature, and circulating slurry volume, the NGH concentration of the NGH slurry is accurately and stably adjusted to the desired value. Continuous control. The NGH slurry generated in the generator 1 in this manner is continuously extracted from the bottom of the generator 1 by the slurry transfer pump 20 and supplied to the bottom of the dehydration tower 2.

[0025] The dehydration tower 2 is formed of a cylindrical vertical container, and a water draining portion 21 is provided in the middle of the tower. The inner wall of the tower corresponding to the water draining portion 21 is a porous wall 22 formed of, for example, a wire mesh or a perforated plate, and water in the dehydration tower 2 is separated into the water draining portion 21 through the porous wall 22. The water in the drain part 21 is extracted by the dehydration circulation pump 24 through the flow control valve 23 and returned to the generator 1. In the vicinity of the top of the dewatering tower 2, a screw conveyor 26 having an opening in a casing (for example, the lower surface) of a part located in the tower is provided. As a result, the water in the NGH slurry introduced into the dehydration tower 2 is separated and removed by the water drainage section 21, and the dehydrated NGH concentration becomes high and NGH slurry becomes the top of the tower. Will be discharged.

 [0026] The NGH concentration in the process of reaching the top of the tower is determined by the fact that the unreacted water is attached to the surface of the granular NGH from the state in which the void portion of the compacted granular NGH is filled with unreacted water. Changes to the state. If this NGH concentration is too low, that is, if there is too much unreacted water contained in NGH, the fluidity of NGH in the fluidized bed gas hydrate generator 3 in the next process will be reduced, and unreacted water and raw materials contained in NGH will be reduced. The gas reaction becomes worse.

[0027] Therefore, the concentration of NGH the dehydrating column 2 (NGHZ (NGH + unreacted water)), for example 45 to 70 wt _^0/0, preferably so as to control the 50 ± 5 weight _^0/0. The NGH concentration is controlled by controlling the amount of extracted water with the flow control valve 23 so that the water level gauge 25 maintains the water level at the drainage portion 21 at the set water level. In other words, the position where the holding power of water held in the gap between NGH and the gravity of water in the tower is balanced from the water level of the drainage section 21 to a certain height position. By appropriately adjusting 28 based on the water level of the drainage section 21, the concentration of NGH carried out by the screw conveyor 26 is controlled to a desired value.

[0028] The fluidized bed gas hydrate generator 3 is formed of a cylindrical vertical container, and natural gas as a raw material gas is supplied to the top of the vertical container. Further, the bottom power of the vertical type container also porous plate 31 is provided at a constant height position, NGH of low concentration which has been conveyed by the screw Konbea 26 above the perforated plate 31 (e.g., 45 to 70 weight _^0/0) There is an introduction port 30 through which is introduced. The vertical container has a suction port at the top, and the suction port of the circulation blower 32 is connected to this suction port! The discharge port of the circulation blower 32 is connected to the bottom of the vertical container, for example, the lower side surface of the container or the bottom of the container. An NGH discharger 38 is provided above the perforated plate 31 in the vertical container so that the dehydrated NGH is carried out to the hopper 4. The discharge machine 38 is provided with a load detector 39 for detecting the load amount. Then, at least one of the circulating gas amount circulated by the circulating gas blower 32, the circulating gas temperature, and the discharge amount of the discharger 38 is controlled so that the load amount detected by the load detector 39 falls within the set range. It comes to be.

The NGH carried out by the discharger 38 is temporarily stored in the hopper 4. Powdered NGH stored in hopper 4 is appropriately cut out via discharge valve 41 to obtain product NGH. Is transferred to the NGH pellet manufacturing equipment, etc. so that it can be cached. Although the inside of the hopper 4 is at a high pressure (for example, 3 to: LOMpa), although not shown in the figure, a depressurization device is usually provided on the downstream side of the discharge valve 41.

 [0030] Next, the fluidized bed gas hydrate generator 3 which is a characteristic part of the present embodiment will be described in detail. The upper inlet of the fluidized bed gas hydrate generator 3 is communicated with the cooler 35 via the raw material gas circulation passage 42, and the raw gas circulation passage 42 is provided with a cyclone 34. Further, the downstream side of the cooler 35 is communicated with the suction port of the circulating gas blower 32 via the thermometer 36. Further, a thermometer 40 is provided in the fluidized bed gas hydrate generator 3.

 [0031] Here, the flow rate of the refrigerant in the cooler 35 is controlled based on the temperature detected by the thermometer 36 and the thermometer 40, and the cooler 35 uses the heat of hydration reaction of the fluidized bed. The rising raw material gas is cooled, and the temperature of the fluidized bed gas hydrate generator 3 is maintained at a low temperature suitable for NGH generation (for example, 1 to 5 ° C.) to promote the reaction.

 The discharge port of the circulating gas blower 32 is connected between the bottom of the vertical container and the perforated plate 31 via a flow rate control valve 33. The discharger 38 is configured by, for example, a screw conveyor, and one end of the screw conveyor is disposed above the perforated plate 31 in the fluidized bed gas hydrate generating device 3, and a casing (for example, the upper surface) located in the vertical container ) With an opening. This screw conveyor is driven by a motor 37. The motor 37 is provided with a torque detector that detects the torque of the output shaft as a load detector 39. The flow rate control valve 33 is controlled so that the torque of the screw conveyor detected by this torque detector falls within the set range, and at least one of the circulating gas amount, the screw conveyor discharge amount, and the refrigerant flow rate of the cooler 35 is controlled. One is in control!

[0033] With this configuration, according to the present embodiment, when natural gas is ejected through the perforated plate 31 to the NGH layer formed by being charged into the fluidized bed gas hydrate generating device 3. An NGH fluidized bed is formed on the perforated plate 31. In this fluidized bed, the unreacted water contained in NGH and the cooled natural gas react actively to effectively increase the hydrate conversion rate of the unreacted water. As a result, the NGH concentration can be increased to, for example, 90% by weight or more. In addition, the NGH concentration in the fluidized bed gas and idrate generator 3 Since there is a correlation as shown in Fig. 2 with the load (torque) of the taree conveyor, in order to control the NGH concentration, the detected value detected by the torque detector is in the desired range. Control at least one of the circulating gas volume, the screw conveyor discharge volume, and the refrigerant flow rate in the cooler 35. Note that NGH discharged from the fluidized bed gas generator / idrate generator 3 has a relatively low amount of unreacted water, for example, 90% by weight, so the amount of unreacted water increases, that is, the NGH concentration decreases. As the load increases, the load on the discharger tends to increase. Thereby, the control for promoting the fluidized bed reaction or the residence time of the fluidized bed reaction is controlled, and the gas hydrate conversion rate of the unreacted water can be controlled. As a result, the concentration of product gas hydrate can be controlled to a desired value, and finally high quality product NGH can be produced stably and continuously.

 [0034] By the way, when controlling the NGH concentration, if the temperature of the circulating gas is lowered too much, the temperature in the vertical container may be lowered too much to generate a gas hydrate having a small particle size. On the other hand, if the gas circulation rate is changed, the fluidized bed in the tower may become unstable. Therefore, when controlling the NGH concentration, it is preferable to first control the discharge amount of the discharger 38 and control the circulating gas amount and the circulating gas temperature as necessary.

 Further, in the present embodiment, a force that uses a screw conveyor as the discharger 38 is not limited thereto, and a known discharge mechanism used for a fluidized bed can be applied. In the present embodiment, the force controlled based on the torque of the screw conveyor is exemplified. The load of the screw compressor may be controlled based on the current value of the motor 37 instead.

[0036] Thus, according to the present embodiment, the NGH concentration can be adjusted by controlling the gas hydrate conversion rate of unreacted water during hydration and dehydration. NGH can be produced stably and continuously.

 [0037] In the above embodiment, the force described in the example in which the vertical container is formed in a cylindrical shape is not limited to this, and the vertical container can be formed in an arbitrary shape such as a rectangle. Further, although the perforated plate 31 is used as the dispersing device, a diffuser tube or the like can be used instead.

[0038] By the way, among the source gases forming the fluidized bed of the fluidized bed gas hydrate generating device 3, the source gas that has not contributed to the hydration reaction is the top of the fluidized bed gas hydrate generating device 3. Are sucked by a circulating gas blower 32 through a cyclone 34. Here, the raw material gas circulated by the circulating gas blower 32 is mixed with fine NGH powder accompanying the flow of the circulating gas from which the top force of the fluidized bed gas hydrate generator 3 is also extracted. The fine NGH powder mixed in the circulating gas depends on the flow velocity at the top of the fluidized bed gas hydrate generator 3, and as shown in FIG. 3, the fluid at the top of the fluidized bed gas hydrate generator 3. A free board portion having a diameter larger than that of the fluidized bed portion may be provided, and the accompanying NGH powder may be reduced by lowering the flow velocity at the top of the fluidized bed gas hydrate generating device 3. For example, when a free board is provided, the limit particle size of the accompanying NGH powder can be suppressed to about 20 / zm. Incidentally, when the diameter of the top is the same as that of the fluidized bed, the limit particle size of the accompanying NGH powder increases to about 100 μm.

 [0039] However, in any case, the top force of the fluidized bed gas hydrate generator 3 is also extracted. Since the raw material gas is mixed with fine NGH powder, it is guided to the cyclone 34 and is subjected to centrifugal force by the NGH powder. Are separated. The NGH powder separated by the cyclone 34 is extracted from the bottom and returned to the fluidized bed gas hydrate generator 3 or generator 1 by a press-fitting means (not shown), for example.

 Thus, according to the present embodiment, fine NGH accompanying the circulating gas circulated in the fluidized bed gas hydrate generator 3 can be effectively separated and collected by the cyclone 34. The fluidized bed gas hydrate generating device can be operated stably and continuously without affecting the power, the circulating gas blower 32 and the cooler 35.

 (Embodiment 2)

FIG. 3 shows a configuration diagram of another embodiment of the fluidized bed gasnoid and idrate generating apparatus according to the present invention. This embodiment differs from the embodiment of FIG. 1 in that an NGH collector 45 is provided in the feed gas circulation passage 42 on the downstream side of the cyclone 34, and the arrangement positions of the cooler 35 and the thermometer 36. Only the position of the porous plate 31 is changed. Since the rest of the configuration is the same as that of the embodiment of FIG. As described above, the cooler 35 and the thermometer 36 are not limited to the upstream side of the circulating gas blower 32 but can be arranged on the downstream side. Further, the perforated plate 31 is not limited to the lower part of the discharger 38 but can be provided at the upper part. In this case, the ejector is opposed to the opening provided in the perforated plate 31. An opening may be provided in the 38 casings.

 FIG. 4 shows a detailed configuration of an embodiment of the NGH collector 45 of FIG. As shown in FIG. 4, the NGH collector 45 of this embodiment includes two series of NGH filters 46A and B. Here, as the NGH filter, for example, a gas filter such as a ceramic filter, metal fiber, or synthetic resin fiber (for example, nylon or Teflon (registered trademark) processed fiber) is used. Since the circulating gas system has a high pressure (for example, 3 to: LOMpa), the NGH filters 46A and B can be formed by accommodating the entire NGH filters 46A and B in pressure vessels. I don't need to consider!

 [0042] The inlets of the NGH filters 46A and B are communicated with the circulating gas outlet of the cyclone 34 via automatic valves 47A and B such as solenoid valves, respectively. The outlets of the NGH filters 46A and B are communicated with the suction port of the circulating gas blower 32 via automatic valves 48A and B, respectively. Each NGH filter 46A, B is provided with a heater 49A, B which is a heating means. As each of the heaters 49A and 49B, for example, a heat transfer tube through which hot water or the like flows or an electric heater can be used. Further, drain nozzles 51A, B equipped with automatic valves 50A, B are provided at the bottom of the NGH filters 46A, B. In addition, purge gas lines 52A and B are installed to purge water that has decomposed and adhered to the filter.

 [0043] The operation of the NGH collector 45 of Fig. 3 configured as described above will be described. First, one of the NGH filters 46A and B is set as the operation side, and the other is set as the standby side. Here, for the sake of explanation, the NGH filter 46A is the operation side and the NGH filter 46B is the standby side. Open the automatic valves 47A and 48A on the driving side and close the automatic valves 47B and 48B on the standby side. As a result, the circulating gas discharged from the cyclone 34 force flows into the NGH filter 46A, and the finer NGH components that are entrained are filtered through the filter and separated from the circulating gas force. As a result, the circulating gas containing almost no NGH powder is sucked into the circulating gas blower 32, so that the influence on the circulating gas blower 32 and the cooler 35 can be avoided.

[0044] When the NGH powder filtered to the filter accumulates on the filter surface in this way, the power loss increases due to the pressure loss of the filter. Therefore, when it is detected that the pressure loss of the filter has increased, or when the automatic valve 47B, 48B on the standby side is opened periodically by a timer, etc., the automatic valve 47A, 48A on the operation side is closed simultaneously. , Filter to drive, NG Switch from H filter 46 A to NGH filter 46B. Thereby, the operation of the fluidized bed gas hydrate generator 3 can be stably continued.

 [0045] The NGH powder accumulated on the filter surface of the NGH filter 46A is heated to a decomposition temperature (for example, 5 ° C or higher) by operating the heater 49A. Return to the water. As a result, clogging due to NGH powder accumulated on the filter surface can be eliminated. The decomposed water is appropriately discharged from the discharge nozzle 51A by opening the automatic valve 50A. The discharged water can be returned to the generator 1, for example. The decomposed water adhering to the filter is removed by purging gas such as raw material gas from the purge gas lines 52A and 52B.

 Thus, according to the NGH collector 45 of the present embodiment, fine NGH accompanying the circulating gas circulated in the fluidized bed gas hydrate generator 3 is collected by the cyclone 34. The NGH collector 45 can collect finer NGH powder that has been collected by the cyclone 34. Therefore, since the fine NGH accompanying the circulating gas can be separated and collected effectively, the fluidized bed gas hydrate generator can be stabilized without affecting the circulating gas blower 32 or the cooler 35. It can be operated continuously.

 [0047] In the above embodiment, the NGH powder deposited on the filter surfaces of the NGH filters 46A and 46B is heated and decomposed by the heaters 49A and 49B. However, the present invention is not limited to this. In short, it is only necessary to decompose the NGH powder deposited on the filter into the original raw material gas and water, so the NGH powder can also be decomposed by reducing the pressure, which is one of the NGH generation conditions. . In this case, pressure reducing means is provided in place of the heaters 49A and 49B.

 (Embodiment 3)

 FIG. 5 shows a configuration diagram of another embodiment of the NGH collector 45 of the embodiment of FIG. In this embodiment, instead of the NGH filter of Fig. 4, an electrostatic collector that collects NGH powder by static electricity is applied. That is, the electrostatic collector shown in FIG. 5 is installed in the horizontal piping section of the circulating gas flow path between the cyclone 34 and the circulating gas blower 32. Further, as in the embodiment of FIG. 4, it is preferable that the entire electrostatic collector is housed in a high-pressure vessel.

[0048] The electrostatic collector is formed by widening the body portion of the casing 55 in order to reduce the flow rate of the circulating gas in consideration of the electrostatic force. A discharge electrode 57 supported by an insulator 56 is provided on the inlet side of the body of the casing 55 connected to the cyclone 34 side. This discharge electrode 57 is a needle A plurality of protrusions are formed and connected to the cathode of a DC high-voltage power supply 58. A plurality of collecting electrodes 59 having a perforated plate force such as a wire mesh are arranged in the flow direction on the body portion of the casing 55 on the downstream side of the discharge electrode 57. The collecting electrode 59 is grounded together with the anode of the high voltage power source 58. The wall surface of the casing 55 below the collecting electrode 59 is formed by a perforated plate 60 such as a wire mesh, and an NGH recovery unit 61 is provided surrounding the perforated plate 60. A heater 62 is disposed inside the collection unit 61. As the heater 62, for example, a heat transfer tube through which hot water or the like flows or an electric heater can be used. A drainage nozzle 64 having an automatic valve 63 such as a solenoid valve is provided at the bottom of the collection unit 61.

 [0049] The operation of the electrostatic collector configured as described above will be described. When the high-voltage power supply 58 is turned on, a discharge is generated from the needle-like protrusions of the discharge electrode 57, and a negative charge is charged to the fine NGH powder that cannot be collected by the cyclone 34. The charged NGH powder is collected by electrostatic force at the collecting electrode 59 connected to the anode of the high-voltage power source 58, that is, the collecting electrode 59 to which a reverse polarity voltage is applied. As a result, fine NGH powder is separated and removed from the circulating gas, and the circulating gas containing almost no NGH powder is sucked into the circulating gas blower 32. The influence can be avoided.

 [0050] Next, if the NGH powder collected on the collection electrode 59 is left unattended, the opening of the collection electrode 59 such as a wire mesh may be blocked. NGH powder needs to be removed. In this embodiment, although not shown in the figure, the connection of the high-voltage power supply 58 is switched, and a voltage having the same polarity as the charged polarity of the NGH powder is applied to the collection electrode 59, and it is peeled off from the collection electrode 59 by electrostatic repulsion. Let's do it. The dropped NGH powder is collected in the collection unit 61, but is decomposed by operating the heater 62. Water generated by the decomposition is appropriately discharged from the discharge nozzle 64 to the generator 1 or the like.

 [0051] Thus, according to the present embodiment, fine NGH accompanying the circulating gas to be circulated in the fluidized bed gas hydrate generator 3 can be effectively separated and collected. The fluidized bed gas hydrate generator without affecting the gas blower 32 and the cooler 35 can be operated stably and continuously.

In the above embodiment, an example in which the discharge electrode 57 is a negative electrode and the collection electrode 59 is an anode is described. The same effect can be obtained even if their polarities are reversed. Collection electrode 59 In this example, a reverse polarity voltage was applied to the collection electrode 59 in order to peel off and drop the NGH powder collected on the NGH powder. The powder can be peeled and dropped. In addition, a heater 62 is provided in the vicinity of the collecting electrode 59, and the collected NGH powder can be decomposed and removed by heating. In addition, the Kashin Daka can also be insulated except for one end of the collecting electrode 59, and the attached NGH powder can be thermally decomposed and removed from the collecting electrode 59 using the collecting electrode 59 itself as an electric heater.

Claims

The scope of the claims  [1] In a gas hydrate production method for producing gas hydrate by reacting raw material gas with water, fluidized bed is obtained by fluidizing granular gas hydrate containing unreacted water with raw material gas. A gas hydrate production method in which gas hydrate is formed by reacting the unreacted water and the raw material gas by a fluidized bed reaction.  [2] A vertical container having an inlet into which a granular gas hydrate containing unreacted water is introduced, a dispersion plate provided between the inlet and the bottom of the vertical container, and the vertical container A raw material gas circulation passage provided with a circulation gas blower for sucking the raw material gas in the vertical container and circulating it to the lower part of the vertical container, such as a suction locuser provided on the upper part of the mold container, and the dispersion plate A fluidized bed gas hydrate generating device comprising an exhauster for discharging the upper gas hydrate.  [3] The fluidized bed gas hydrate generator according to [2], wherein the raw material gas circulation passage is provided with a cooler for cooling the raw material gas. [4] The load amount of the discharger is detected, and the amount of the raw material gas circulated by the circulating gas blower, the temperature of the raw material gas, and the discharge amount so that the detected load amount falls within a set range. 4. The fluidized bed gas hydrate generating device according to claim 3, further comprising control means for controlling at least one of the discharge amounts of the machine. 5. The fluidized bed gas hydrate generator according to any one of claims 2 to 4, wherein a cyclone that collects gas hydrate contained in the source gas is provided in the source gas circulation passage.  [6] The collector according to claim 5, wherein a collector for collecting a finer gas hydrate contained in the source gas discharged from the cyclone is provided in the source gas circulation passage. Fluidized bed gas hydrate generator. [7] The collector is provided with two series of alternately switchable filters for filtering the fine gas hydrate and heating means for heating the filter. 6. The fluidized bed gas hydrate generator according to 6. [8] The collector includes two series of alternately switchable filters for filtering the fine gas hydrate, and a pressure reducing means for reducing the pressure of the source gas in the filter to a set pressure. The fluidized bed gas hydrate generator according to claim 6, wherein the fluidized bed gas hydrate generator is provided. [9] The collector includes a discharge electrode charged to the fine gas hydrate, a collection electrode to which a voltage having a polarity opposite to the charge of the gas hydrate charged by the discharge electrode is applied, 7. The fluidized bed gas hydrate generator according to claim 6, which is an electrostatic collector having a means for removing the gas hydrate collected by the collecting electrode also from the collecting electrode force. 10. The fluidized bed gas hydrate generator according to claim 9, wherein the removing means for removing the gas hydrate from the collecting electrode is means for vibrating the collecting electrode.  [11] The removal means for removing the gas hydrate from the collecting electrode is means for applying a voltage having the same polarity as the charge of the gas hydrate to the collecting electrode. The fluidized-bed gas hydrate production | generation apparatus of description. 12. The fluidized bed gas / idrate generator according to claim 9, wherein the removing means for removing the gas hydrate from the collecting electrode is means for heating the collecting electrode.