WO2007145261A1

WO2007145261A1 - Hydrate production apparatus

Info

Publication number: WO2007145261A1
Application number: PCT/JP2007/061942
Authority: WO
Inventors: Yoshitaka Yamamoto; Taro Kawamura; Akihiro Wakisaka; Kazuo Matsuura
Original assignee: National Institute Of Advanced Industrial Science And Technology; Ultrasound Brewery
Priority date: 2006-06-14
Filing date: 2007-06-13
Publication date: 2007-12-21
Also published as: JP2007330891A; JP4998772B2

Abstract

[PROBLEMS] To increase the rate of production of a hydrate by decreasing the average particle size of microparticles of water, and to convert a raw material gas into a hydrate at high efficiency. [MEANS FOR SOLVING PROBLEMS] Disclosed is a hydrate production apparatus which can atomize water in the form of microparticles and enables the contact of the atomized water microparticles with a raw material gas under cooled conditions, thereby producing a hydrate. The apparatus comprises: a closed chamber (1) to which the raw material gas is introduced; an ultrasonic oscillator (2) for causing the ultrasonic oscillation of water supplied into the closed chamber (1) to atomize water in the form of microparticles in the raw material gas; a reactor (3) to which the microparticles atomized by the ultrasonic oscillator (2) is transferred together with the raw material gas; a transfer duct (4) for transferring the raw material gas containing the water microparticles from the closed chamber (1) to the reactor (3); and a cooler (5) for cooling the reactor (3) to bring the inside of the reactor (3) into the condition suitable for the reaction between the water microparticles and the raw material gas transferred by the transfer duct (4).

Description

Specification

Hydrate production equipment

Technical field

[0001] The present invention relates to an apparatus for producing an idrate by reacting a raw material gas such as carbon dioxide gas or natural gas in the air with fine particles of water.

Background art

[0002] An apparatus for producing a hydrate by reacting a raw material gas with water has been developed. A simple device can be made into an idrate by putting ice in a container filled with source gas and stirring. In this device, ice force and surface force stirred inside the container also reacts with the raw material gas to become hydrate. The device with this structure cannot produce hydrates efficiently! /.

[0003] As an apparatus for increasing the production efficiency, an apparatus has been developed in which water is sprayed from a nozzle into a pressure tank filled with a raw material gas to form fine particles and idrate. (See Patent Document 1)

Patent Document 1: Japanese Patent Laid-Open No. 2001-342473

Disclosure of the invention

Problems to be solved by the invention

[0004] As shown in FIG. 1, the apparatus described in the publication of Patent Document 1 includes a reaction tank 91 that generates hydrate. The reaction tank 91 is a pressure vessel, and a cooling coil 92 is provided inside. The cooling coil 92 cools and holds the aqueous phase L in the reaction tank 91 at about 1 ° C. as a temperature for generating hydrate. When generating the hydrate, the force hydrate that generates heat of hydration can only be generated at low temperature and high pressure, so it is cooled by the cooling coil 92. Further, the illustrated apparatus includes a water tank 93. The water tank 93 supplies water to the reaction tank 91 through the pipe 94, and the bottom of the reaction tank 91 is the water phase L. Further, a methane inlet 9 la is provided at the lower part of the reaction tank 91. This methane introduction port 91a is connected to a gas storage unit 97, and this force is also supplied with methane gas as a raw material gas. The methane supplied to the reaction tank 91 keeps the pressure of the gas phase G at 40 atm with the pressure for generating the nodule. At the bottom of the reaction tank 91, a water outlet 91b for extracting unreacted water is provided. Drain outlet 91b Is connected to a spray nozzle 98 at the upper end of the reaction tank 91 via a pump 95 and a heat exchanger ^ 96. The spray nozzle 98 cools the water to a temperature at which a noise rate can be generated by heat exchange 96 and sprays it as fine particles inside the reaction tank 91. The spray nozzle 98 sprays water as fine particles of several tens / zm downward into the reaction tank 91. By reducing the average particle size of the fine particles sprayed from the spray nozzle 98, the surface area per unit volume of water, that is, the contact area with the gas phase G can be increased, and hydrates can be generated quickly.

[0005] Further, Patent Document 1 also describes an apparatus that uses an ultrasonic vibration plate 80 in place of the spray nozzle 98 as shown in FIG. The ultrasonic vibration plate 80 is horizontally disposed on the upper part of the reaction tank 81. Water is supplied from the pipe 82 above the ultrasonic vibration plate 80. The supplied water forms a water film 83 on the ultrasonic vibration plate 80. The water film 83 is released into the reaction tank 81 as fine particles by ultrasonic vibration. With this structure, it is not necessary to inject a gas for making water into fine particles unlike the spray nozzle 98, and the particle diameter of the water can be made uniform.

However, depending on the structure described above, the raw material gas cannot be hydrated efficiently and quickly. This is because the average particle size of fine particles cannot be made smaller than a micron unit in a structure using a spray nozzle. Moreover, even if a water film is provided on the ultrasonic vibration plate and this is made into fine particles by ultrasonic vibration, water cannot be atomized efficiently into fine particles having a small average particle diameter.

[0007] In order to efficiently produce idrate, it is important how the average particle size of the fine water particles can be reduced. This is because as the average particle size decreases, the surface area per volume increases and the raw material gas and water react quickly to increase the production rate. In addition, reducing the average particle size of the fine water particles is also effective in increasing the proportion of the raw material gas contained in the generated nodrate. Furthermore, the reaction efficiency between water and the raw material gas, in other words, the ratio of the produced hydrate containing the raw material gas can be improved by lowering the temperature. However, if the temperature is lowered, the production rate of the reaction tank is slowed down. To increase the reaction efficiency, it is important to reduce the average particle size of the fine water particles even when the temperature is lowered.

[0008] The present invention reduces the average particle size of the fine water particles to increase the production rate and improve the efficiency. It was often developed for the purpose of making the source gas hydrate.

Means for solving the problem

The hydrate manufacturing apparatus of the present invention has the following configuration in order to achieve the above-described object.

The idrate production apparatus atomizes water into fine particles, and makes the fine particles of atomized water and raw material gas contact in a cooled state to form a hydrate. The idrate manufacturing apparatus includes a sealed chamber 1 to which a raw material gas is supplied, and an ultrasonic vibrator 2 that atomizes water supplied to the sealed chamber 1 by ultrasonic vibration into fine particles in the raw material gas. A reaction chamber 3 in which fine particles atomized by the ultrasonic vibrator 2 are transported together with the raw material gas, and a transfer for transferring the raw material gas containing fine water particles from the sealed chamber 1 to the reaction chamber 3 A duct 4 and a cooler 5 that cools the reaction chamber 3 and uses fine particles of water and raw material gas transferred in the transfer duct 4 as a reaction environment are provided.

In the hydrate manufacturing apparatus of the present invention, the sealed chamber 1 includes a water reservoir 6 at the bottom, and an ultrasonic vibrator 2 is disposed at the bottom of the water reservoir 6. The water reservoir 6 can be atomized into fine particles by ultrasonic vibration.

[0011] In the hydrate production apparatus of the present invention, the raw material gas can be air containing carbon dioxide or natural gas.

[0012] The hydrate manufacturing apparatus of the present invention is configured to forcibly blow a forced feed into the reaction chamber 3 by sucking a raw material gas containing fine particles of water in the sealed chamber 1 between the sealed chamber 1 and the reaction chamber 3. Transporter 8 can be connected.

The invention's effect

[0013] The hydrate production apparatus of the present invention is characterized in that the average particle size of fine water particles is reduced to increase the production rate, and the raw material gas can be efficiently hydrated. Figures 3 and 4 are graphs showing the state in which methane hydrate is generated. Fig. 3 shows the characteristics of the production apparatus of the present invention for generating hydrate, and Fig. 4 shows the characteristics of the production apparatus of Fig. 1 for generating hydrate. However, in these figures, the horizontal axis represents the time axis, and the vertical axis represents the relative value at which hydrate is generated. As is apparent from FIGS. 3 and 4, the production apparatus of the present invention can dramatically improve the hydrate generation speed as compared with the conventional apparatus. Furthermore, in FIGS. 3 and 4, the amount of hydrate produced after 6 hours is set to 1, and therefore the hydrate rate after 6 hours is not the same in FIGS. 3 and 4. The manufacturing apparatus of the present invention shown in FIG. 3 can considerably improve the hydrate rate as compared with the conventional apparatus shown in FIG. This is because when the particle size of fine water particles is changed using the conventional apparatus shown in Fig. 1, the hydrate rate power after 6 hours changes from 5.6% to 19.7%. It is. Here, the hydrate rate is a value indicating (number of moles of water containing methane) Z (number of moles of water) [molZmol]. The production apparatus of the present invention can remarkably reduce the particle size of water fine particles and the micro-order force of the conventional apparatus as nano-order. From this, the production apparatus of the present invention can significantly improve the idrate rate and can produce gas hydrate efficiently.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiments described below exemplify a hydrate manufacturing apparatus for concretely illustrating the technical idea of the present invention, and the present invention does not specify the manufacturing apparatus as follows.

[0016] Further, in this specification, in order to facilitate understanding of the claims, the numbers corresponding to the members shown in the embodiments are referred to as "Claims" and "Means for solving the problems". It is added to the member shown by. However, the members shown in the claims are not limited to the members in the embodiments.

[0017] The hydrate production apparatus shown in FIG. 5 atomizes water into fine particles, and contacts the atomized water fine particles with the raw material gas in a cooled state to obtain an idrate. This manufacturing apparatus uses air or natural gas containing carbon dioxide as raw material gas. However, the apparatus of the present invention does not specify the source gas as air or natural gas. As the source gas, any gas that can be made into an idrate can be used. Hydrate is generated using air containing carbon dioxide as the raw material gas, and the aerodynamic force can also separate carbon dioxide. This is because carbon dioxide gas is efficiently hydrated compared to nitrogen and oxygen contained in the air. For this reason, hydrate is generated from the exhaust gas containing carbon dioxide in the air, and the exhaust gas force can also separate the carbon dioxide, and the separated carbon dioxide can be converted into a hydrate convenient for disposal.

[0018] Further, by using natural gas as a noble rate, the volume can be reduced to about 1/160 of the gas state. wear. For this reason, natural gas can be made into a favorable state for transportation as a hydrate state. Currently, natural gas is cooled and liquidized to reduce the volume and transport it. Natural gas transported in this state must be kept at a very low temperature to prevent vaporization. For this reason, the transport device requires a special device for keeping it in a cryogenic state. Hydrate natural gas can be transported with simpler equipment than liquefied. This is because the temperature maintained in the idrate is higher than the temperature maintained in the liquefied state. Therefore, natural gas can be easily and efficiently transferred by making the natural gas hydrate with the production apparatus of the present invention. In this case, it is important how efficiently and quickly the natural gas can be hydrated, but the apparatus of the present invention can efficiently generate natural gas into the hydrate.

The hydrate production apparatus shown in FIG. 5 includes a sealed chamber 1 for supplying a raw material gas, and an ultrasonic wave that atomizes water into the fine particles in the raw material gas by ultrasonically oscillating water in the sealed chamber 1. The vibrator 2, the reaction chamber 3 in which the fine particles atomized by the ultrasonic vibrator 2 are transported together with the raw material gas, and the raw material gas containing fine water particles from the sealed chamber 1 to the reaction chamber 3 are transferred. It includes a transfer duct 4 to be sent, and a cooler 5 that cools the reaction chamber 3 and uses the fine particles of water transferred by the transfer duct 4 and a source gas as a reaction environment.

[0020] The sealed chamber 1 is filled with a source gas by supplying a source gas such as natural gas or exhaust gas. Unlike the spray nozzle used in the conventional apparatus, the ultrasonic vibrator 2 does not inject pressurized air or the like into the sealed chamber 1 in order to atomize water. For this reason, the production apparatus of the present invention can fill the sealed chamber 1 with the raw material gas. The closed chamber 1 filled with the raw material gas atomizes the water particles to be atomized as fine particles in the raw material gas. In the device that atomizes fine water particles into the raw material gas, the atomization efficiency is affected by the water particle concentration of the raw material gas. Atomization by ultrasonic vibration can increase the efficiency by lowering the water particle concentration of the source gas. In order to realize this state, the apparatus shown in the figure continuously supplies a raw material gas to the sealed chamber 1, and further continuously discharges a raw material gas containing water particles. The sealed chamber 1 in the figure supplies a source gas from one side and discharges a source gas containing water particles from the opposite side. The sealed chamber 1 moves the atomized water particles to the atomization region force and supplies fresh raw material gas containing no water particles to the atomization region. The sealed chamber 1 having this structure allows the raw material gas to flow in a certain direction to efficiently atomize water particles. Atomization This is because the water particle concentration of the source gas in the region can be lowered.

[0021] Further, the water particle concentration in the atomization region also affects the particle size of the water particles to be atomized. The particle size of the water particles to be atomized can be reduced by lowering the water particle concentration in the atomization region. As shown in the figure, the raw material gas is flowed in a fixed direction in the sealed chamber 1 to cause the raw material gas in the atomization region containing water particles to flow, and the atomization region contains water particles. However, an apparatus for supplying fresh raw material gas can reduce the particle size of fine particles.

[0022] The flow rate of the raw material gas supplied to the sealed chamber 1 is determined to an optimum value in consideration of the atomization amount of water particles. The amount of atomization of water particles is specified by the input power of the ultrasonic transducer 2. The amount of atomization with respect to the input power of the ultrasonic vibrator 2 varies depending on the efficiency of the ultrasonic vibrator 2, but for example, the ultrasonic vibrator 2 with an input power of 10 W is approximately 0.5 liters per hour. Atomize 1 liter of water. Therefore, the flow rate of the raw material gas with respect to the input power of 10 W of the ultrasonic vibrator 2 is 10 liters Z minutes or more, preferably 15 liters Z minutes or more, more preferably 20 liters Z minutes or more. If the flow rate of the raw material gas with respect to the input power of the ultrasonic vibrator 2 is too large, the water particles contained in the raw material gas are reduced. For this reason, the flow rate of the raw material gas with respect to the input power of 10 W of the ultrasonic vibrator 2 is preferably 100 liters Z or less.

[0023] Furthermore, the flow rate of the raw material gas is also specified by reacting the raw material gas with water of fine particles to form a hydrate. The theoretical ratio of fine particle water to source gas is 5.75 mol Z1.0 mol assuming that all source gases are hydrated (in the case of type I methane hydrate, the gas species and the structure to be generated) ) O In practice, specify the appropriate water and gas supply in consideration of the reaction efficiency of atomized water and gas.

The sealed chamber 1 is a tank that is hermetically sealed and has a water reservoir 6 at the bottom. An ultrasonic transducer 2 is disposed at the bottom of the water reservoir 6. The ultrasonic transducer 2 is connected to an ultrasonic power source 7 and ultrasonically vibrates the water in the water reservoir 6. The ultrasonic vibrator 2 is vibrated with an ultrasonic wave having a frequency higher than the audible frequency, for example, 20 kHz to 10 MHz. The vibration frequency of the ultrasonic vibrator 2 affects the particle size of the water particles to be atomized. Increasing the vibration frequency of the ultrasonic vibrator 2 can reduce the particle size of the atomized water particles. However, if the vibration frequency of the ultrasonic vibrator 2 is too high, the efficiency is lowered, and it is difficult to manufacture an element that vibrates at an extremely high frequency. From this, the frequency of the ultrasonic transducer 2 is preferably 1 to 5 MHz. Optimally, it should be 2-3MHz.

[0025] The water reservoir 6 of the sealed chamber 1 has a water depth at which water can be efficiently atomized. If the depth of the water reservoir 6 is too shallow, water cannot be atomized efficiently. If the depth of the water reservoir 6 is less than 5 mm, water cannot be atomized efficiently. Even if the depth of the water reservoir 6 is deeper than 5 cm, water cannot be efficiently atomized. Therefore, for example, when the input power of the ultrasonic vibrator 2 is 10 W and the vibration frequency is 10 kHz to 5 MHz, the water depth of the water reservoir 6 is preferably 1 cm to 5 cm, and more preferably 1 cm to 3 cm. However, since the optimum water depth of the water reservoir portion varies depending on the frequency of the ultrasonic transducer and the input power, the present invention does not specify the water depth of the water reservoir portion within the aforementioned range.

[0026] The ultrasonic vibrator 2 is horizontally fixed to the bottom of the water reservoir 6, and ultrasonically vibrates water up and down. However, the ultrasonic vibrator can also be disposed in the water reservoir in a slightly inclined posture to cause ultrasonic vibration of the water. Further, although not shown, an ultrasonic vibrator can be disposed in the water supplied to the sealed chamber, and the water supplied to the sealed chamber can be atomized by ultrasonic vibration. Since this structure cannot atomize all the water supplied to the sealed chamber, it collects the bottom force water of the sealed chamber and repeatedly supplies it to the sealed chamber to atomize some of the supplied water. .

The water is cooled and supplied to the sealed chamber 1. The water is frozen when cooled to below 0 ° C, so it is higher than 0 ° C and as close to 0 ° C as possible, for example, cooled to 0 ° C to 5 ° C, and supplied to the closed chamber 1 . The apparatus shown in the figure supplies water stored in a water tank 10 to a sealed chamber 1 by a water pump 11. In the apparatus shown in the figure, the water supplied by the water pump 11 is further cooled by the cooler 5 and supplied to the sealed chamber 1.

[0028] The sealed chamber 1 can improve the atomization efficiency of water by reducing the internal pressure. In the manufacturing apparatus shown in the figure, a forced transfer device 8 is connected to the sealed chamber 1 to reduce the internal pressure. The forced transfer device 8 is connected between the closed chamber 1 and the reaction chamber 3 and sucks the raw material gas containing water particles into the closed chamber 1 and forcibly transfers it to the reaction chamber 3. The forced transfer device 8 is a compressor such as a roots blower or a compressor such as a reshorm compressor. This device can reduce the closed chamber 1 to below atmospheric pressure with the forced transfer device 8 and improve the atomization rate of water. The sealed chamber 1 that has been depressurized below the atmospheric pressure increases the atomization efficiency and smoothly sucks the raw material gas. [0029] The sealed chamber 1 has an outlet 1A that is connected to the suction side of the forced transfer device 8. Furthermore, the sealed chamber 1 shown in the figure is provided with a demister 9 for removing atomized large water particles at the discharge port 1A. This apparatus removes large water particles contained in the raw gas discharged from the sealed chamber 1 and supplies water fine particles to the reaction chamber 3, so that the average of the water fine particles supplied to the reaction chamber 3 is averaged. The particle size can be reduced. For this reason, fine water particles can be supplied to the reaction chamber 3 to efficiently generate hydrate. The device shown in the figure is a force that removes large water particles by installing a demister 9 at the outlet 1A. Instead of demister 9, a mechanism that separates large water particles, for example, large water particles are condensed on the surface and separated. A mechanism or the like can be provided between the sealed chamber and the reaction chamber.

[0030] The reaction chamber 3 is a pressure vessel, and a raw material gas containing water particles supplied from the sealed chamber 1 is cooled by a forced transfer device 8 in a pressurized state to generate a noble rate of the raw material gas. The temperature and pressure at which the raw material gas reacts with water and produces idrate is specified by the raw material gas. For example, natural gas reacts with water at atmospheric pressure and below 30 ° C to produce hydrate. Therefore, the reaction chamber 3 cools the temperature to 50 ° C. and generates a natural gas hydrate at atmospheric pressure. However, the reaction chamber 3 can generate natural gas hydrate at 30 ° C. or lower, preferably −50 ° C. or lower, more preferably 170 ° C. or lower. Since the reaction chamber 3 of the pressure-resistant vessel can be pressurized with the raw material gas transferred by the forced transfer device 8, the temperature at which hydrate is generated can be lowered as the pressurized state. Therefore, when the reaction chamber 3 is in a pressurized state to generate a hydrate of natural gas, the temperature of the reaction chamber 3 can be higher than the set temperature described above. When the raw material gas reacts with water to produce hydrate, heat of reaction is generated. The reaction chamber 3 is cooled by the cooler 5 so that the temperature of the reaction chamber 3 does not increase due to the heat of reaction.

[0031] The reaction chamber 3 is provided with a rotary feeder 12 at the bottom for taking out the hydrate in a sealed state. The rotary feeder 12 rotates the rotor to discharge the hydrate accumulated at the bottom while keeping the reaction chamber 3 sealed.

The manufacturing apparatus shown in the figure includes a heat exchanger 13 that cools water supplied to the sealed chamber 1, a heat exchanger 14 that cools the sealed chamber 1, and a source gas containing water particles supplied to the reaction chamber 3. And heat exchange 16 for cooling the reaction chamber 3. Each heat The interchanges l3, 14, 15, 16 are connected to a chiller (not shown) and cooled by a cooling medium supplied from the chiller. Since each of the heat exchangers 13, 14, 15, and 16 has a different temperature for cooling the water and the raw material gas, a control valve (not shown) for controlling the circulation amount of the refrigerant is provided so as to be an optimum temperature. ing.

Industrial applicability

[0033] In the present invention, since the production rate of hydrate can be dramatically improved and the raw material gas can be efficiently converted into a noble gas, the raw material gas such as carbon dioxide gas or natural gas in the air is in a hydrated state. It is extremely effective in storage, transportation and supply means.

Brief Description of Drawings

FIG. 1 is a schematic configuration diagram of a conventional hydrate manufacturing apparatus.

FIG. 2 is an enlarged sectional view showing another example of reducing the particle size of fine particles in a conventional manufacturing apparatus.

FIG. 3 is a graph showing characteristics of producing hydrate by a hydrate manufacturing apparatus according to an embodiment of the present invention.

FIG. 4 is a graph showing the characteristics of a conventional hydrate manufacturing apparatus that generates hydrate.

FIG. 5 is a schematic configuration diagram of a hydrate manufacturing apparatus according to an embodiment of the present invention. Explanation of symbols

1 ····· Closed chamber 1Α ··· Discharge port

2 ... Ultrasonic vibrator

3 ··· Reaction chamber

4'Transport duct

5 · Cooler

6 ... Water reservoir

·. '· Ultrasonic power supply

8. Forced transfer device

9 '' Demister

10 · · · Aquarium 1 ... Water pump

2 ... Rotary feeder

3 ...

4… Heat exchanger

5 ... Heat exchanger

6 ... heat exchange

0 ... Ultrasonic diaphragm

1 ... Reaction tank

2 ... Piping

3 ... Water film

1 ··· Reaction tank 9 la… Methane inlet

91b ... Drain outlet 2 ... Cooling coil

3 ... Water tank

4 ... Piping

5 ... Pump

6 ... Heat exchanger

7 ... Gas storage

8 ... Spraynos' Nore

L ... Water phase

Claims

The scope of the claims

[1] A device for producing an idrate by atomizing water into fine particles and bringing the atomized fine water particles and the raw material gas into contact with each other in a cooled state.

A sealed chamber (1) to which a source gas is supplied, an ultrasonic vibrator (2) that atomizes water supplied to the sealed chamber (1) by ultrasonic vibration into fine particles in the source gas, A reaction chamber (3) in which fine particles atomized by the ultrasonic vibrator (2) are transported together with the raw material gas, and a raw material gas containing fine particles of water from the sealed chamber (1) to the reaction chamber (3) A transfer duct (4) for transferring the reaction chamber, and a cooler (5) for cooling the reaction chamber (3) and using fine particles of water and raw material gas transferred in the transfer duct (4) as a reaction environment. Hydrate manufacturing equipment provided.

[2] The sealed chamber (1) is provided with a water reservoir (6) at the bottom, and an ultrasonic vibrator (2) is disposed at the bottom of the water reservoir (6). The hydrate manufacturing apparatus according to claim 1, wherein the water reservoir (6) is ultrasonically vibrated to atomize into fine particles.

[3] The apparatus for producing a nodule according to claim 1, wherein the raw material gas is air containing carbon dioxide gas.

[4] The hydrate production apparatus according to claim 1, wherein the source gas is natural gas.

[5] Forced transfer device that sucks the raw material gas containing fine water particles in the sealed chamber (1) between the sealed chamber (1) and the reaction chamber (3) and forcibly blows air into the reaction chamber (3) ( The apparatus for producing a hydrate according to claim 1, wherein 8) is connected.