JPH0796888A - Deep-sea submerged co2 storage device - Google Patents

Abstract

PURPOSE:To store liquid CO2 underwater without diffusion or dissolution in the sea water, by charging and sealing the liquid CO2 in a liquid-tight bag so as to obtain packed liquid CO2, and by submerging the packed liquid CO2 onto the deep-sea bottom through a vertically long pipe under the pressure of discharged air. CONSTITUTION:Liquid CO2 in a tank 2 on a charging station 1 is pressurized by a pressurizing pump 4 up to about 40 atm. and is then fed to a heat- exchanger 5 where the temperature thereof is raised up to 0 deg.C. Then, the CO2 is introduced into a lock hopper so as to be packed into an unpermeable bag. The packed liquid CO2 is shifted into a charge pipe 9 which has been previously pressurized up to 40 atm, and is suspended from weights 13a, 13b provided at both ends of a long wire 12 by means of hooks (h). Then, the packed liquid CO2 together with the weight 13a, is lowered by about 400m so as to reach the surface of the sea water in the charge pipe 9. Further, after it reaches at a depth 15 of 300m from the sea level, where the relationship between the specific weight of the sea water and that of the liquid CO2 are reversed, the packed liquid CO2 3e is submerged onto the sea bottom for storage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CO ₂ deep-sea storage device for safely storing CO ₂ contained in gases such as industrial exhaust gas on the ocean floor with minimal impact on the environment.

[0002]

2. Description of the Related Art In recent years, the concentration of CO ₂ in the atmosphere has increased due to the increased use of fossil fuels. On the other hand, CO ₂ is considered to be one of the global warming substances, and a means for reducing the increase of carbon dioxide in the atmosphere is considered. As one of the means, a means for charging CO ₂ into the deep sea and storing it is known. As an example thereof, in FIG. 4, the carbon dioxide recovered from the concentrated emission sources such as power plants, as a liquid CO ₂ was carried in the ship (not shown) to the offshore base 101, the liquid CO ₂ 102a from the ship tank 103 Transfer to. The liquid CO ₂ 102a in the tank 103 is sent by a pump 104 to a deep sea of 3000 m or more in the ocean through a pipe 105. In this deep sea, the magnitude relationship between the specific gravity of the liquid CO ₂ 102a and the specific gravity of the seawater is reversed, so that the liquid CO ₂ 102b sinks under its own weight and accumulates on the seabed 106.

[0003]

However, such a CO ₂ deep-sea charging and storing means has the following problems. Liquid CO ₂ introduced into the ocean dissolves in seawater and pH
Cause a decline in water quality and its impact on marine life. If liquid CO ₂ is stored on the ocean floor for a long period of time, CO ₂ will diffuse from the CO ₂ lumps on the ocean floor, making it difficult to collect liquid CO ₂ .

The present invention has been proposed in view of the above circumstances, and the liquid CO ₂ which has been submerged and stored in the deep sea floor for a long period of time is diffused and dissolved in seawater to cause the pH of the seawater.
Of the stored liquid CO ₂
It is an object of the present invention to provide a highly safe CO ₂ deep-sea charging storage device that enables recovery of CO ₂ as needed.

[0005]

To this end, the present invention is an apparatus for charging liquid CO ₂ into the deep sea and charging and storing the liquid CO ₂ in the deep sea floor at a water depth of about 3000 m or more. the liquid CO ₂ of disposed liquid CO ₂ in tank sucked by pump, which together with pressurized to a pressure which does not vaporize seawater temperature, is introduced into the lock hopper as more seawater freezing point through the heat exchanger liquid C
An O ₂ pipeline, a bag-filled liquid CO ₂ obtained by filling and sealing a liquid-tight bag brought into the lock hopper with a liquid CO ₂ introduced from the liquid CO ₂ line, and a central portion of the horizontal station. An inverted U-shaped vertical long-length feeding pipe having a recoverable weight that extends through it in the vertical direction and has an opening at the lower end at a water depth of about 3000 m, and that descends with the bagged liquid CO ₂ ; A pair of left and right pulleys driven by a generator and a motor at the upper end U-turn part of the length-filling pipe, and a wire cable sewn around the pulleys at both ends can be remotely attached and detached with the bagging liquid CO ₂ respectively. Suspended weight and discharge air arranged on the other side of the station are supplied to the upper part of the vertical long feed pipe through the lock hopper, and seawater in the vertical long feed pipe is supplied. Characterized in that comprises an air compressor pushing down the free surface level of the water depth of about 400 meters.

[0006]

According to such a structure, the following actions are exhibited. (1) In the center of the station, there is a heavy weight of about 3000
An inverted U-shaped long pipe of m is hung vertically, and C is installed on both sides of it.
Since _two heavy equipments, an O ₂ pump and an air compressor, are installed respectively, the load applied to the station is balanced, and the attitude of the station can be stabilized against wind waves. (2) Bagging avoids contact of liquid CO ₂ with seawater and avoids dissolution of carbon dioxide in seawater. (3) The pressure of the liquid CO ₂ is kept at about 40 atm which does not vaporize at the temperature of seawater. (4) The temperature of liquid CO _{2 at} the time of contact with seawater is maintained at 0 ° C. or higher. Therefore, it is possible to prevent the related members from freezing due to freezing of seawater. (5) When the liquid CO _{2 is} charged and until it reaches the sea surface, power is generated by utilizing the fall of the bagged liquid CO ₂ . Bagging liquid CO ₂ at a weight which is connected to the self-weight of the bag-filling liquid CO ₂
The bagging liquid CO ₂ is transferred to a depth of about 3,000 m which is settled only by its own weight, and at that point, the bagging liquid CO ₂ is separated from the lift, that is, the wire, so that the bagging liquid C ₂ is separated.
O ₂ sinks to the ocean floor.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an overall longitudinal sectional view thereof, and FIG. 2 is a diagram showing a relationship between temperature and pressure with respect to seawater depth of water and liquid CO ₂ in seawater, FIG. 3 is a diagram showing the relationship between seawater and the density of liquid CO ₂ in seawater with respect to the depth of seawater.

First, referring to FIG. 1, the overall structure will be described. 1 is a plurality of devices for levitating to the sea surface by a plurality of floating bodies arranged on the lower surface, and a plurality of devices for introducing liquid CO ₂ to be described later on the upper deck. It is a horizontal rectangular CO ₂ charging station on which members are mounted. 4 is disposed on the right end side of the station 1, the liquid CO _2, which is reserved in the liquid CO ₂ tank 2
3a is pressurized to pass through the heat exchanger 5, the CO ₂ pipe 20 and the branched CO ₂ pipes 20a and 20b, and then the station 1
Is a pressurizing pump for supplying to the lock hoppers 7 arranged at the left end side and the right end side of the central part of the branch CO ₂ pipe 2
A valve e is inserted at a position near the lock hopper 7 in each of 0a and 20b. 6 is provided on the left end side of the station 1 and supplies air to the air pipe 21 and the branch air pipe 2
The air compressors 2 and 23 supply the lock hoppers 7 and 7 on the left end side and the right end side, respectively, and air valves b are inserted at positions near the lower ends of the branch air pipes 22 and 23, respectively. Here, a slide base f movable inward is provided on the bottom plates of the pair of left and right lock hoppers 7, 7, and a hatch type valve d is provided on each outer wall of each lock hopper 7. A hatch-type valve a is attached to each wall, and each hatch-type valve a is provided between the partition wall opening of each lock hopper 7 and the opening of the outer wall through which the upper end portion of the input pipe 9 described later penetrates the station 1 upward. It is arranged.

Reference numeral 9 is an inverted U-shaped pipe having a length of about 3000 m in the vertical direction, the bottom end of which is open,
The upper end U-turn portion 25 of the charging pipe 9 vertically penetrates the central portion of the station 1 and projects onto the upper deck thereof. Reference numeral 10 denotes a generator disposed on the central portion of the U-turn portion 25, and a generator for driving the motor 11 disposed inside the U-turn portion 25. Reference numerals 26 are symmetrically disposed on the left and right sides of the motor 11. Each of the pulleys 13a and 13b is a weight and has a pair of left and right hooks h at the left and right ends of the lower surface.
The motors 11a and 13b are suspended by a motor 11 via a long wire cable 12 and a pulley 26 so as to be alternately movable up and down. 3c _L is a liquid-tight bag filled with liquid CO ₂ in the left lock hopper 7 (hereinafter referred to as bagged liquid CO ₂ ) and 3 c _R is a liquid-tight bag in a contracted state in the right lock hopper 7. Yes, both liquid tight bags 3
c _L and 3 c _R are made of bags made of vinyl chloride, polyethylene, etc. that are impermeable to liquid CO ₂ . Reference numeral 3d denotes a bagging liquid CO ₂ bag suspended from the lower end hook h of the weight 13a by a remote control operation, and 3e denotes a bagging liquid which is detached from the hook h and drops from the weight 13a to the seabed. It is CO ₂ .

Next, the physical properties of liquid CO _{2 in} seawater will be described. First, FIG. 2 shows the temperature and pressure corresponding to the water depth at one point in the South China Sea. Here, the seawater, as shown by ■, increases as the water depth, that is, the pressure, increases.
Its temperature drops. Further, it can be seen that the liquid CO ₂ has a pressure at which the liquid CO ₂ does not vaporize at a water depth of 400 m, that is, 40 atm.

Next, FIG. 3 shows the relationship between the water depth, that is, the pressure, and the density. With seawater, the density increases linearly with a small gradient as the pressure increases, as indicated by the ● mark. , CO ₂ , as the pressure increases, the density of the CO ₂ increases from a large ascending gradient to a gradually decreasing gradient as compared with seawater. Here, since both density lines intersect at a water depth of 3000 m and a density of less than 1.05, liquid CO ₂ floats at a water depth of 3000 m as a boundary, and becomes deeper than the density of seawater in deeper water. It can be seen that the seafloor sinks to the seafloor under its own weight.

Now, returning to FIG. 1, the operation of the lock hopper in the device of the present invention will be described. The liquid CO ₂ 3a transferred from the land and stored in the liquid CO ₂ tank 2 on the charging station 1 is the liquid CO ₂ After being taken out by the pressure pump 4 and pressurized to 40 atm, the temperature is raised to 0 ° C. by the heat exchanger 5. The liquid CO ₂ 3b is supplied to the pump 6
Is introduced into the lock hopper 7 pressurized to 40 atm with
It is packed in a liquid-tight or impermeable bag 8. The liquid CO ₂ 3 c _L packed in the bag is transferred to the charging pipe 9 which is pressurized to 40 atm in advance, and the liquid CO transferred to the charging pipe 9 is transferred.
₂ 3c _L can be given a driving force by the motor 11 connected to the generator 10 to control the falling speed.
The long wire 12 having a length of 000 m or more is suspended by weights 13a and 13b attached to both ends by a hook h.

Packing liquid CO ₂ in the lock hopper 7
The manufacturing process of 3 c _L and the process of charging it into the charging pipe 9 will be described in detail below. First, the hatch type valve a and the air valve b are opened, and the inside of the charging pipe 9 is pressurized to 40 atmospheric pressure by the air conditioner pusher 6. Next, the hatch type valve a and the air valve b are closed, and the hatch type valve d
When the lock hopper 7 is opened, the lock hopper 7 is decompressed and an empty liquid-tight bag 8 is installed therein. Here, after the hatch type valve d is closed and the hatch type valve a is opened, the lock hopper 7 is pressurized by the air compressor 6. Thus
When the inside of the charging pipe 9 and the inside of the lock hopper 7 have the same pressure, the hatch type valve a is closed and the liquid CO ₂ with the valve e opened is filled in the empty liquid tight bag 3c _L. . After bagging, the CO ₂ valve e is closed and the hatch type valve a
Is opened and the liquid CO ₂ 3c is bagged by the slide base f.
_{The L} is sent into the charging pipe 9, and is hung on the weight h by being hooked on the hook h by remote control via the wire cable 12.

The connected bagged liquid CO ₂ 3d, together with the weight 13a, descends a distance of about 400 m and reaches the sea level 14 in the charging pipe 9 while generating power. At this point in time, the bagged liquid CO ₂ 3d has a smaller specific gravity than seawater, and the weights 13a and 13b of the deadweights are in balance with each other, and the seawater level 14
Float on. Then, the weight 13b on the opposite side is pulled up by the motor 11, and the liquid CO ₂ 3d settles under the weight of the weight 13a. Then, after reaching a depth of 15 at a depth of 3000 m where the specific gravity of seawater and the specific gravity of liquid CO ₂ reverse, the bagged liquid CO ₂ 3e is removed from the weight 13a by remote control and continues to settle to reach the seabed 16. After that, it is stably stored for a long period of time. At this time, the bagging liquid CO ₂ is connected to the weight 13b on the opposite side pulled up to the uppermost part in the same manner as the weight 13a, so that the liquid CO ₂ is alternately charged and stored in the same manner. Be seen.

[0015]

According to such an apparatus, the following effects can be obtained. (1) By packing liquid CO ₂ in a CO ₂ impermeable bag to prevent contact with seawater, environmental damage due to dissolution in seawater can be suppressed, and at the same time clogging of the input pipe due to clathrate generation is prevented. be able to. (2) Since the liquid CO ₂ is pressurized to a pressure at which it does not vaporize at seawater temperature, vaporization of the liquid CO ₂ due to heat exchange can be prevented. (3) After pressurization, the temperature of the liquid CO ₂ becomes 0 due to heat exchange.
Since the temperature is kept above ℃, it is possible to prevent the generation of ice due to contact with seawater. (4) Power is generated by the falling energy of the liquid CO ₂ and the weight, so that the energy for lifting the weight after dropping the liquid CO ₂ is covered. (5) In the center of the station, there is a heavy weight of about 300
An inverted 0-meter long U-shaped pipe is hung vertically, and CO ₂ pumps and air compressors are installed on both sides of the pipe. The posture can be stabilized. (6) The bagged liquid CO ₂ stored in the deep sea floor can be recovered via a wire cable of a long feeding pipe, if necessary.

In short, according to the present invention, in a device for charging liquid CO ₂ into the deep sea and charging and storing the liquid CO ₂ in the deep sea bottom at a water depth of about 3000 m or more, it is arranged on one side of a horizontal station that floats above the sea surface. Liquid C in liquid CO ₂ tank
O ₂ is sucked by a pump, and it is pressurized to a pressure that does not evaporate at seawater temperature, and is introduced into the lock hopper and a liquid CO ₂ pipeline that is introduced into the lock hopper above the freezing point of seawater via a heat exchanger. The liquid-tight bag is filled with the liquid CO ₂ introduced from the liquid CO ₂ line and sealed, and the bag-filled liquid CO ₂ extends vertically through the central portion of the horizontal station to a depth of about 3,000 m.
Has an opening at the lower end of the bag and is filled with the above-mentioned bagged liquid CO ₂
Inverted U-shaped vertical long loading pipe having a recoverable weight that descends together with it, and the upper end U of the vertical long loading pipe
A pair of left and right pulleys driven by a generator and a motor in the turn portion, and a weight for detachably suspending the bagged liquid CO ₂ by remote control at both lower ends of the wire cable wound around in a spiral manner. , The discharge air disposed on the other side of the station is supplied to the upper portion of the vertical long throw-in pipe through the lock hopper to bring the free surface of seawater in the vertical long throw-in pipe to a level of about 400 m in depth. By including the air compressor that pushes down, liquid CO ₂ that has been settled and stored in the deep sea floor for a long period of time is prevented from diffusing and dissolving in seawater and lowering the pH of seawater. INDUSTRIAL APPLICABILITY The present invention is extremely useful industrially because a highly safe CO ₂ deep-sea storage device capable of recovering CO ₂ as needed is obtained.

[Brief description of drawings]

FIG. 1 is an overall vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between temperature and pressure with respect to seawater depth of seawater and CO ₂ in seawater.

FIG. 3 is a diagram showing the relationship between seawater and the density of CO ₂ in seawater with respect to the depth of seawater.

FIG. 4 is an overall side view showing a conventionally known deep-sea CO ₂ storage device.

[Explanation of symbols]

1 charging station 2 liquid CO ₂ tanks 3a, 3b, 3c liquid CO ₂ 3c _L , 3c _R liquid-tight bag (packed liquid CO ₂ ) 3d, 3e bag-filled liquid CO ₂ 4 CO ₂ pressure pump 5 heat exchanger 6 Air compressor 7 Lock hopper 8 Liquid-tight bag 9 Input pipe 10 Generator 11 Motor 12 Wire cable 13a, 13b Weight 14 Sea water level 15 Specific gravity reversal depth 16 Seabed 20 CO ₂ pipe 20a, 20b Branch CO ₂ pipe 21 Air pipe 22, 23 Branch air pipe 25 U-turn section 26 Pulley 101 Ocean base 102a, 102b Liquid CO ₂ 103 Tank 104 Pump 105 Piping 106 Seabed a Hatch type valve b Air valve d Hatch type valve e CO ₂ valve f Slide base h Hook

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Masahiko Ozaki 5-717-1, Fukahori-cho, Nagasaki-shi, Nagasaki Sanryo Heavy Industries Ltd. Nagasaki Research Institute

Claims (1)

[Claims] 1. An apparatus for charging liquid CO ₂ into the deep sea and charging and storing it in the deep sea floor at a water depth of about 3000 m or more, in a liquid CO ₂ tank disposed on one side of a horizontal station that floats above the sea surface. the liquid CO ₂ is sucked by the pump, which together with pressurized to a pressure which does not vaporize seawater temperature, and liquid CO ₂ pipeline to be introduced into the lock hopper as more seawater freezing point through the heat exchanger, in the lock hopper and bagging liquid CO ₂ to the brought in liquid liquid CO ₂ to be introduced into tight bag from the liquid CO ₂ line formed by filling and sealing, about depth extending vertically through the central portion of the horizontal station 3000m of which has an opening at the lower end, the inverted U-shaped vertical long turned pipe having a weight of recoverable descending with the bag filling liquid CO _2, of the vertical long-on pipe Weight of Jisuru hanging the end U-turn portion to the generator and each bag filling liquid CO ₂ a pair of left and right pulleys and to both the lower end of the wire cable which is wound sieved Tsurube expression driven by a motor detachably remotely The discharge air, which is arranged on the other side of the weight and the station, is supplied to the upper part of the vertical long throw-in pipe through the lock hopper so that the free surface of seawater in the vertical long throw-in pipe has a depth of about 400 m. A CO ₂ deep-sea charging and storage device characterized by having an air compressor that pushes down to a level.