JP2006213894A - Apparatus for producing gas hydrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain gas hydrate production facilities which are simple and efficient by integrating a gas hydrate production apparatus composed of a plurality of apparatuses. <P>SOLUTION: The apparatus for producing a gas hydrate in a high concentration comprises reacting water (w) with a gas (g) to produce a gas hydrate (h) and then dehydrating the gas hydrate. In the apparatus, a hydrate-producing apparatus 1 for producing the gas hydrate (h) by reacting water (w) with the gas (g) and a hydrate dehydration apparatus 2 for separating water in the gas hydrate (h) produced in the hydrate-producing apparatus 1 are vertically arranged. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a gas hydrate production apparatus for producing a gas hydrate from a guest gas (for example, natural gas) and water, and dehydrating the gas hydrate to produce a gas hydrate with little attached water.

  Currently, as a method of storing and transporting mixed gas (for example, natural gas mainly composed of hydrocarbons such as methane), after collecting natural gas from a gas field, it is cooled to a liquefaction temperature and liquefied natural gas (LNG) However, in order to store natural gas as LNG and then transport it, high-performance refrigeration equipment and storage facilities are required.

  For this reason, it has been intensively studied to hydrate natural gas, which is a mixed gas, with water to produce a solid state hydrate, that is, natural gas hydrate (NGH), which is stored or transported in this solid state. ing. Since this natural gas hydrate can be produced under conditions of temperature and pressure that are relatively easily obtained, production, storage and transportation costs are low, and has attracted attention in this field.

  By the way, natural gas hydrate is obtained by bringing a raw material gas into contact with water and solidifying it as a hydrate. Usually, however, unreacted water is produced, so that it becomes a slurry containing a large amount of water. ing.

  Therefore, if the slurry-like natural gas hydrate is stored and transported, there is a problem that the net amount of gas is small and the cost for storing and transporting becomes enormous.

For this reason, it is necessary to introduce slurry-like natural gas hydrate into a dehydrator to dehydrate and remove unreacted water. Regarding the method for producing a mixed gas hydrate with a small amount of attached water, since the properties of the gas hydrate are drastically changed by the change in the amount of attached water, it is generally produced in multiple stages (see, for example, Patent Document 1).
JP 2004-10686 A

  In Patent Document 1, a gas hydrate generating device (first step) having a water supply means and a raw material gas supply means is provided with means for recovering gas hydrate. A high concentration in which the moisture content of the gas hydrate is increased by the second step of the regas hydration apparatus that further hydrates the adhering components remaining in the clustered gas hydrate recovered by the means for recovering the gas hydrate. The gas hydrate can be used.

  However, since the reaction apparatus is divided into the first process hydrate generation apparatus and the second process hydrate generation apparatus, it is difficult to transport the product gas hydrate from the first process to the second process. There was a problem. Further, in terms of equipment, there is a problem in that a transportation facility is required between the first process hydrate generating device and the second process hydrate generating device, and thus a complicated and large space is required.

  The present invention has been made in order to solve such many problems, and the object of the present invention is to integrate a gas hydrate generating device composed of a plurality of devices into a simple and efficient manner. A gas hydrate production facility is provided.

  In order to solve the above problems, the present invention is configured as follows.

  An apparatus for producing a gas hydrate according to a first aspect of the present invention is an apparatus for producing gas hydrate by reacting water and gas to produce gas hydrate and then dehydrating the gas hydrate to produce a high concentration gas hydrate. A hydrate generator for generating gas hydrate by reacting water and gas, and a hydrate dehydrator for separating the moisture of the gas hydrate produced by the hydrate generator. Is a gas hydrate production apparatus characterized by the above.

  A gas hydrate manufacturing apparatus according to the invention of claim 2 is manufactured by a hydrate generating apparatus in which a hydrate generating apparatus is disposed on a hydrate dewatering apparatus, and both apparatuses are connected by a slurry conveying pipe. 2. The gas hydrate production apparatus according to claim 1, wherein the gas hydrate slurry is caused to flow down to a hydrate dewatering device through a slurry conveying pipe.

  A gas hydrate production apparatus according to the invention of claim 3 is provided outside the apparatus by scraping the gas hydrate dehydrated by the hydrate dehydrator into a vertical hydrate discharge pipe provided in the apparatus. 3. The gas hydrate production apparatus according to claim 2, wherein the gas hydrate production apparatus is discharged.

  A gas hydrate production apparatus according to a fourth aspect of the present invention includes a hydrate dewatering device disposed on a hydrate production device, and hydrate dehydration produced by the hydrate production device by a pump. The gas hydrate production apparatus according to claim 1, wherein the apparatus is pushed up to the apparatus.

  As described above, according to the first aspect of the present invention, after gas hydrate is produced by reacting water and gas, the gas hydrate is dehydrated to obtain a gas hydrate having a high concentration, that is, a low water content. In a manufacturing apparatus, a hydrate generating apparatus that reacts water and gas to generate a gas hydrate, and a hydrate dehydrating apparatus that separates moisture of the gas hydrate manufactured by the hydrate generating apparatus up and down. Because of the arrangement, the number of pipes is significantly reduced as compared with the conventional case, and the gas hydrate manufacturing apparatus can be made compact and simplified. Furthermore, since the connecting pipe between the hydrate generator and the hydrate dehydrator can be shortened, the loss of cooling energy can be reduced.

  According to the second aspect of the present invention, the hydrate generating device is disposed on the hydrate dewatering device, and both devices are connected by a slurry transfer pipe, and the gas hydrate slurry produced by the hydrate generating device is transferred to the slurry. Since it is made to flow down to the hydrate dewatering device through the pipe, power is not necessary for conveying the gas hydrate slurry, or even when necessary, power is small and economical.

  In the third aspect of the invention, the gas hydrate dehydrated by the hydrate dewatering device is scraped into a vertical hydrate discharge pipe provided in the device and discharged to the outside of the device. Hydrate can be easily taken out.

  In the invention according to claim 4, the hydrate dewatering device is disposed on the hydrate generating device, and the gas hydrate slurry produced by the hydrate generating device is pushed up to the hydrate dewatering device by a pump. The rate slurry can be dehydrated at a constant flow rate, and the flow rate can be arbitrarily changed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(1) First Embodiment As shown in FIG. 1, this gas hydrate production apparatus is an apparatus in which a hydrate generator 1 is integrally installed on a hydrate dehydrator 2 via a partition plate 3. Yes, both devices are connected via a hydrate slurry transport pipe 4.

  More specifically, the hydrate dewatering device 2 has a double structure, and the large-diameter bottomed tank 5 on the outside is integrally formed with the covered tank 6 of the hydrate generating device 1 above. Is formed. Moreover, the bottomed tank 5 of the hydrate dewatering device and the covered tank 6 of the hydrate generating device are partitioned by a partition plate 3 that protrudes downward.

  On the other hand, the small-diameter bottomed tank 7 of the hydrate dewatering device 2 passes through the bottom of the large-diameter bottomed tank 5 of the hydrate dewatering device 2, and is provided with a screw conveyor 8 as a conveying device at the top. Yes. The screw conveyor 8 penetrates the side surface of the large-diameter bottomed tank 5 of the hydrate dewatering device 2 and protrudes to the outside. Further, the small-diameter bottomed tank 7 of the hydrate dewatering device 2 is provided with a draining portion 9 made of a wire mesh or a porous layer (porous member) on its side surface. The draining portion 9 is located above the bottom of the large-diameter bottomed tank 5.

  The hydrate generator 1 has a gas discharge pipe 10 that discharges a mixed gas g such as natural gas in the form of bubbles, and a stirring device 11 thereabove. The hydrate generator 1 may be provided with a guide (not shown) for promoting the rise of the generated gas hydrate.

  Further, the side portion of the hydrate generating device 1 and the side portion of the small-diameter tank 7 of the hydrate dewatering device 2 are connected by a hydrate slurry transport pipe 4 having a flow rate adjusting valve 12 for controlling the flow rate. The upper part of the hydrate slurry transport pipe 4 and the upper part of the hydrate generator 1 are connected by a communication pipe 13. In addition, when a hydrate slurry can be used, it is preferable to apply an axial flow pump (not shown) to the hydrate slurry transport pipe 4.

  Further, the upper part of the hydrate generator 1 and the gas discharge pipe 10 are connected by a line 15 having a blower 14 and a cooler 34, and the bottom of the hydrate generator 1 and the measuring part are cooled with a pump 16. They are connected by a line 18 with a device 17.

  Further, the outer cylinder (large diameter bottomed tank) 5 of the hydrate dewatering device 2 and the side portion of the hydrate generating device 1 are connected by a line 20 having a pump 19. In addition, a raw material gas supply pipe 21 is provided at the upper part of the hydrate generator 1, and a raw water supply pipe 22 is provided on the side of the hydrate generator 1 with an outer cylinder (large diameter) of the hydrate dehydrator 2. The bottomed tank) 5 is provided with a pressure equalizing line 23 for taking out the unreacted gas in the outer cylinder (large diameter bottomed tank) 5.

Here, when the pressure of the hydrate generator 1 is P ₁ (MPa) and the pressure of the hydrate dehydrator 2 is P ₂ (MPa), the following equation is set.
P ₁ ≧ P ₂

Next, the operation of this gas hydrate production apparatus will be described.
Now, when the raw material water w in the hydrate generator 1 is stirred by the stirring device 11, the mixed gas g in the hydrate generator 1 is bubbled from the gas discharge pipe 10 into the raw water w by the blower 14. The mixed gas g and the raw material gas w undergo a hydration reaction under predetermined conditions (for example, a temperature of 1 to 5 ° C. and a pressure of 5 MPa) to generate a gas hydrate h.

  Since this gas hydrate h is lighter than water (specific gravity: 0.8 to 0.9), the gas hydrate h rises in the hydrate generator 1 and the pressure difference between the hydrate generator 1 and the hydrate dehydrator 2 and gravity. Is supplied from the hydrate generating device 1 to the hydrate dewatering device 2 below the hydrate slurry conveying pipe 4.

  In the hydrate generator 1, an apparatus for removing the reaction heat of gas hydrate generation is necessary. The slurry liquid in the hydrate generator 1 is externally circulated through the external circulation line 18 and is cooled by the cooler 17. Removes heat. In FIG. 1, the raw material water w is directly supplied to the hydrate generator 1, but may be supplied to the slurry external circulation line 18. Unreacted source gas g is circulated through a line 15 having a blower 14 and a cooler 34.

  In the hydrate dehydrator 2, the gas hydrate slurry s produced by the hydrate generator 1 is dehydrated to generate a high-concentration gas hydrate h. The generated high-concentration gas hydrate (for example, water content: 50 to 55%) h is taken out from the hydrate dehydrator 2. The high-concentration gas hydrate h is taken out from the side surface of the hydrate dehydrator 2 in FIG. 1, but may be taken out from the bottom (see FIG. 2).

  The hydrate production | generation apparatus 2 is a gravity dehydration apparatus using the gravity difference of gas hydrate and water. The gas hydrate slurry s supplied to the bottom of the bottomed small-diameter tank 7 rises in the bottomed small-diameter tank 7 of the hydrate dewatering device 2. The water w of the gas hydrate slurry s rising in the bottomed small-diameter tank 7 is discharged from the pores opened in the side surface of the bottomed small-diameter tank 7 of the hydrate dewatering device 2, and the dehydrated gas hydrate h is Further, it is lifted and taken out to the next process by a screw conveyor 8 as a discharge device.

  The water w discharged from the pores opened in the side surface of the bottomed small-diameter tank 7 of the hydrate dewatering device 2 is stored in the jacket portion 24 between the bottomed large-diameter tank 5 and the bottomed small-diameter tank 7. The pump 19 returns the hydrate generator 1.

  2 and 3 show one embodiment of the hydrate discharge device, which is an alternative device to the screw conveyor of FIG. This is because the gas hydrate h dehydrated by the bottomed small-diameter tank 7 of the hydrate dewatering device 2 is collected by the scraper 25 at the center of the bottomed small-diameter tank 7 and the tapered pipe 26 penetrating through the bottom of the bottomed small-diameter tank 7. It is designed to discharge outside.

  The scraper 25 is composed of an impeller in which a plurality of curved blades 27 are arranged radially, and is attached to the lower surface of the worm gear 28. The shaft 29 of the worm gear 28 is supported by the bottomed large-diameter tank 5 by a support 30. The worm 31 for the worm gear 28 is driven by a motor 32 outside the tank.

(2) Second Embodiment FIG. 4 shows an example in which the hydrate generating device 1 is installed in the lower part of the hydrate dewatering device 2. In this example, the gas hydrate slurry s generated by the hydrate generator 1 is conveyed to the hydrate dehydrator 2 via a line 38 including a pump 35 and a cooler 36, and a high-concentration gas hydrate (for example, water content) Rate: 50-55%) h.

  More specifically, the hydrate dewatering device 2 has a double structure, and the large-diameter covered tank 5a on the outside is integrated with the bottomed tank 6a of the hydrate generating device 1 below. Is formed. In addition, the covered tank 5a of the hydrate dewatering device and the bottomed tank 6a of the hydrate generating device are partitioned by a downwardly projecting partition plate 3.

  On the other hand, a small-diameter tank (dehydration tower) 7a provided in the hydrate dewatering device 2 is provided with a screw conveyor 8 serving as a transport device at the upper portion thereof. The screw conveyor 8 penetrates the side surface of the large-diameter covered tank 5a of the hydrate dewatering device 2 and protrudes to the outside. Further, the small-diameter tank (dehydration tower) 7a of the hydrate dewatering device 2 is provided with a draining portion 9 made of a wire mesh or a porous layer (porous member) on its side surface. The small-diameter tank (dehydration tower) 7 a of the hydrate dehydrator 2 is supported by an annular support plate 39.

  In addition, about another site | part, the same code | symbol is provided to the same site | part as the gas hydrate manufacturing apparatus of 1st Embodiment, and detailed description is abbreviate | omitted.

  In the case of this example, the raw material water w in the hydrate generator 1 is stirred by the stirring device 11 and the mixed gas g in the hydrate generator 1 is bubbled from the gas discharge pipe 10 into the raw water w by the blower 14. Then, the gas g and the water w undergo a hydration reaction under a predetermined condition (for example, a temperature of 1 to 5 ° C. and a pressure of 5 MPa) to generate a gas hydrate h.

  Since this gas hydrate h is in the form of a slurry in the hydrate generator 1, it is conveyed to the hydrate dehydration tower 2 via a line 38 including a pump 35 and a cooler 36. At this time, a part of the gas hydrate slurry s is circulated to the hydrate generator 1 via the line 37.

  In the hydrate dewatering device 2, the gas hydrate slurry s produced by the hydrate generating device 1 is dehydrated to generate a high concentration gas hydrate h. The generated high-concentration gas hydrate (for example, water content: 50 to 55%) h is taken out from the hydrate dehydrator 2 by the screw conveyor 8.

  The hydrate dewatering device 2 is a gravity dewatering device using the gravity difference between gas hydrate and water. The gas hydrate slurry s supplied to the bottom of the small-diameter tank (dehydration tower) 7a rises in the small-diameter tank (dehydration tower) 7a of the hydrate dehydrator 2. The water w of the gas hydrate slurry s that has risen in the small-diameter tank (dehydration tower) 7a is discharged from the pores formed in the side surface of the small-diameter tank (dehydration tower) 7a of the hydrate dehydrator 2 and dehydrated. The gas hydrate h is further raised and taken out to the next process by the screw conveyor 8 which is a discharge device.

  The water w discharged from the pores opened in the side surface of the small-diameter tank (dehydration tower) 7a of the hydrate dewatering device 2 is stored in the jacket part 24 between the covered large-diameter tank 5a and the small-diameter tank (dehydration tower) 7a. After that, the pump 19 returns the hydrate generator 1.

It is a 1st schematic block diagram of the gas hydrate manufacturing apparatus which concerns on this invention. It is a schematic block diagram of the alternative means of a hydrate taking-out apparatus. FIG. 3 is a top view of FIG. 2. It is a 2nd schematic block diagram of the gas hydrate manufacturing apparatus which concerns on this invention.

Explanation of symbols

w water g gas h gas hydrate s gas hydrate slurry 1 hydrate generator 2 hydrate dehydrator 3 partition plate

Claims (4)

After gas hydrate is produced by reacting water and gas, gas hydrate is produced by reacting water and gas in an apparatus for producing gas hydrate having a high concentration by dehydrating the gas hydrate. A gas hydrate production apparatus, wherein a hydrate production apparatus and a hydrate dehydration apparatus for separating the moisture of gas hydrate produced by the hydrate production apparatus are arranged above and below. A hydrate generator is placed on top of the hydrate dehydrator, and both devices are connected by a slurry transport pipe, and the gas hydrate slurry produced by the hydrate generator flows down to the hydrate dehydrator through the slurry transport pipe. The gas hydrate manufacturing apparatus according to claim 1, wherein: 3. The gas hydrate production according to claim 2, wherein the gas hydrate dehydrated by the hydrate dewatering device is scraped into a vertical hydrate discharge pipe provided in the device and discharged outside the device. apparatus. 2. The gas hydrate according to claim 1, wherein a hydrate dehydrator is disposed on the hydrate generator, and a gas hydrate slurry produced by the hydrate generator is pushed up to the hydrate dewaterer by a pump. Manufacturing equipment.

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