AU2021371586B2

AU2021371586B2 - Method for transferring liquefied carbon dioxide, and floating structure

Info

Publication number: AU2021371586B2
Application number: AU2021371586A
Authority: AU
Inventors: Kazuya Abe; Shinsuke Morimoto
Original assignee: Mitsubishi Shipbuilding Co Ltd
Current assignee: Mitsubishi Shipbuilding Co Ltd
Priority date: 2020-10-28
Filing date: 2021-10-28
Publication date: 2024-08-15
Anticipated expiration: 2041-10-28
Also published as: EP4215798A4; KR20230070023A; AU2021371586A1; EP4215798A1; JP2022071535A; CN116420044B; WO2022092217A1; JP7365992B2; CN116420044A

Abstract

A method for transferring liquefied carbon dioxide according to the present invention includes the steps of: connecting a connection pipe for connection to an external facility arranged in the outside of a floating body to piping that communicates with the inside of a tank provided to the floating body; replacing the insides of the connection pipe and the piping with a replacement gas by feeding the replacement gas having the moisture content adjusted to smaller than or equal to a predetermined upper limit value into the insides of the connection pipe and the piping; replacing the insides of the connection pipe and the piping with a carbon dioxide gas from the replacement gas; and transferring the liquefied carbon dioxide between the external facility and the tank through the connection pipe and the piping.

Description

METHOD FOR TRANSFERRING LIQUEFIED CARBON DIOXIDE, AND FLOATING STRUCTURE

Technical Field

[0001]

The present disclosure relates to a method for

transferring liquefied carbon dioxide, and a floating

structure.

Priority is claimed on Japanese Patent Application No.

2020-180560, filed October 28, 2020, the content of which

is incorporated herein by reference.

Background Art

[0002]

For example, in PTL 1, a configuration including a

transfer device (natural gas transfer device) for

transferring liquefied gas from a ship (import ship)

provided with a tank for storing a liquefied gas (liquefied

natural gas (LNG)) to a facility (import terminal) on land

is disclosed. In such a configuration, the ship moored at

the facility on land communicates fluidly with the facility

and transfers the liquefied gas in the tank to the storage

tank on land.

Citation List

Patent Literature

[00031

[PTL 1] PCT Japanese Translation Patent Publication

No. 2010-503132

Summary of Invention

[0004]

Incidentally, when the liquefied gas is loaded into

the tank from an external facility such as a facility on

land or when the liquefied gas in the tank is unloaded to

the external facility, the pipes such as the loading pipe

or the unloading pipe provided in the tank are connected to

the external facility via a connection pipe. However, when

connecting the connection pipe to the pipe, there is a

possibility that air (atmosphere) intrudes the inside of

the pipe. Then, in a case where the liquefied carbon dioxide

is accommodated in the tank, when air intrusion into the

pipe occurs, the moisture contained in the air reacts with

the carbon dioxide, and carbonic acid or hydrate is formed.

When carbonic acid or hydrate is formed in this manner,

there is a possibility that corrosion occurs inside the pipe

or the tank.

[0005]

Therefore, after the connection pipe is connected to

the pipe of the tank, the connection pipe is filled with

carbon dioxide gas. As a result, direct contact of the

moisture contained in the air with the liquefied carbon

dioxide is suppressed. However, also in this case, when the carbon dioxide gas is filled, there is a possibility that the moisture contained in the air in the connection pipe reacts with the carbon dioxide, resulting in corrosion inside the tank or the pipe.

[00061

Preferred embodiments of the present invention seek to

provide a method for transferring liquefied carbon dioxide

and a floating structure that can suppress the reaction

between carbon dioxide and moisture when the liquefied

carbon dioxide is transferred, and suppress occurrence of

corrosion of the inside of the tank or the pipe.

[0007]

In accordance with one aspect of the present invention,

there is provided a method for transferring liquefied carbon

dioxide comprising: a step of connecting a connection pipe

for connection to an external facility disposed outside a

floating structure, to a pipe communicating with an inside

of a tank provided in the floating structure; a step of

feeding a replacement gas having a moisture content adjusted

to be equal to or less than a predetermined upper limit

value into the connection pipe and the pipe, and replacing

an inside of the connection pipe and the pipe with the

replacement gas; a step of replacing the replacement gas

inside the connection pipe and the pipe with a carbon

dioxide gas; and a step of transferring liquefied carbon dioxide between the external facility and the tank through the connection pipe and the pipe.

[00081

In accordance with another aspect of the present

invention, there is provided a floating structure comprising:

a floating main structure; a tank disposed in the floating

main structure and capable of storing liquefied carbon

dioxide; a pipe which communicates with an inside of the

tank and to which a connection pipe for supplying liquefied

carbon dioxide between an external facility and the tank is

connectable; a replacement gas supply unit that feeds a

replacement gas having a moisture content adjusted to be

equal to or less than a predetermined upper limit value into

the pipe and the connection pipe in a case where the

connection pipe is connected to the pipe; and a carbon

dioxide supply unit that feeds a carbon dioxide gas into

the pipe and the connection pipe, wherein the replacement

gas supply unit includes an air dryer that reduces an amount

of moisture contained in an atmosphere taken in from an

outside.

Advantageous Effects of Invention

[00091

According to the method for transferring liquefied

carbon dioxide and the floating structure according to the

present disclosure, it is possible to suppress the reaction between the carbon dioxide and the moisture when the liquefied carbon dioxide is transferred, and to suppress the occurrence of corrosion inside the tank or the pipe.

Brief Description of Drawings

[0010]

Fig. 1 is a plan view showing a schematic configuration

of a ship as a floating structure according to an embodiment

of the present disclosure.

Fig. 2 is a view showing a tank and a pipe provided in

the ship according to the embodiment of the present

disclosure, and is a sectional view taken along line I-I of

Fig. 1.

Fig. 3 is a view showing the tank and the pipe provided

in the ship according to the embodiment of the present

disclosure, and is a sectional view taken along line II-II

of Fig. 1.

Fig. 4 is a diagram showing an external facility

connected to the ship according to the embodiment of the

present disclosure by a connection pipe.

Fig. 5 is a flowchart showing a procedure of a method

for transferring liquefied carbon dioxide according to the

embodiment of the present disclosure.

Fig. 6 is a view showing a step of connecting the

connection pipe in the method for transferring liquefied

carbon dioxide according to the embodiment of the present disclosure.

Fig. 7 is a view showing a step of replacing with a

replacement gas in the method for transferring liquefied

carbon dioxide according to the embodiment of the present

disclosure.

Fig. 8 is a view showing a step of replacing with a

carbon dioxide gas in the method for transferring liquefied

carbon dioxide according to the embodiment of the present

disclosure.

Fig. 9 is a view showing a step of transferring

liquefied carbon dioxide in the method for transferring

liquefied carbon dioxide according to the embodiment of the

present disclosure.

Description of Embodiments

[0011]

Hereinafter, a floating structure and a method for

transferring liquefied carbon dioxide according to

embodiments of the present disclosure will be described with

reference to Figs. 1 to 9.

(Configuration of Ship)

As shown in Figs. 1 and 2, in the embodiment of the

present disclosure, a ship 1 which is a floating structure

carries liquefied carbon dioxide. The ship 1 includes at

least a hull 2 as a floating main structure, a tank facility

10, a replacement gas supply unit 20 (refer to Fig. 2), and a carbon dioxide supply unit 30 (refer to Fig. 2).

[0012]

(Configuration of Hull)

The hull 2 has a pair of sides 3A and 3B, a bottom 4

(refer to Fig. 2), and an upper deck 5, which form an outer

shell thereof. The sides 3A and 3B each have a pair of side

shell platings which form the left and right sides on both

sides in a ship width direction Dw. The bottom 4 is disposed

below in a vertical direction Dv and has a bottom shell

plating connecting these sides 3A and 3B to each other. As

shown in Fig. 2, due to the pair of sides 3A and 3B and the

bottom 4, the outer shell of the hull 2 has a U-shape in a

cross section orthogonal to a stem-stern direction Da. The

upper deck 5 shown in this embodiment is a continuous deck

exposed to the outside. In the hull 2, a superstructure 7

having an accommodation space is formed on the upper deck 5

on a stern 2b side.

[0013]

Inside the hull 2, a cargo tank storage compartment

(hold) 8 is formed on a stem 2a side of the superstructure

7. The cargo tank storage compartment 8 is recessed toward

the bottom below the upper deck 5, and is open upward.

[0014]

(Configuration of Tank Facility)

A plurality of tank facilities 10 are disposed in the cargo tank storage compartment 8 along the stem-stern direction Da. In the embodiment of the present disclosure, two tank facilities 10 are disposed at intervals in the stem-stern direction Da.

[0015]

As shown in Figs. 2 and 3, the tank facility 10

includes at least a tank 11 and a pipe 12.

In this embodiment, the tank 11 is disposed on the

hull 2. The tank 11 has, for example, a cylindrical shape

extending in the horizontal direction. In this embodiment,

the tank 11 is disposed in the long axis direction along

the stem-stern direction Da. The tank 11 accommodates a

liquefied carbon dioxide L inside thereof. The tank 11 is

not limited to a cylindrical shape, and the tank 11 may have

a spherical shape, a square shape, or the like.

[0016]

The pipe 12 includes a loading pipe 13 and an unloading

pipe 14. That is, as the pipe 12 of the tank facility 10,

there are two types of pipes, the loading pipe 13 and the

unloading pipe 14.

As shown in Fig. 3, the loading pipe 13 forms a pipe

line for loading the liquefied carbon dioxide L supplied

from an external facility 100 (refer to Fig. 4) on the

outside of the ship, such as an on-land liquefied carbon

dioxide supply facility, into the tank 11. A part of the loading pipe 13 on a side close to one end 13a thereof penetrates the top of the tank 11 and extends from the outside to the inside of the tank 11. A part of the loading pipe 13 on a side close to the one end 13a extends in the vertical direction Dv inside the tank 11. The one end 13a of the loading pipe 13 opens in the tank 11 at the lower portion of the tank 11.

[0017]

The rest of the loading pipe 13, that is, a part on a

side close to the other end 13b is disposed outside the tank

11. As shown in Fig. 2, the other end 13b of the loading

pipe 13 is provided with a connection portion 13j connected

to the outside of the ship. The connection portion 13j has,

for example, a flange or the like. The connection portion

13j is disposed toward one (for example, the side 3A) of

the sides 3A and 3B. The opening of a connection portion

14j is normally blocked by a lid (not shown). By removing

the lid (not shown) of the connection portion 13j, it is

possible to connect the end portion of the connection pipe

50 for connection to a facility side tank 101 of the external

facility 100 in place of the lid (not shown).

[0018]

The unloading pipe 14 delivers the liquefied carbon

dioxide L in the tank 11 to the external facility 100 on

the outside of the ship. A part of the unloading pipe 14 on a side close to one end 14a penetrates the top of the tank 11 from the outside of the tank 11 and extends to the inside of the tank 11. The one end 14a of the unloading pipe 14 is disposed in the lower portion inside the tank 11.

A pump (not shown) is provided at the one end 14a of the

unloading pipe 14. The pump (not shown) sucks the liquefied

carbon dioxide L in the tank 11 and delivers the liquefied

carbon dioxide L to the unloading pipe 14. The unloading

pipe 14 guides the liquefied carbon dioxide L delivered from

the pump to the outside of the tank 11 (the outside of the

ship).

[0019]

A part of the unloading pipe 14 on a side close to the

other end 14b, which is the rest of the unloading pipe 14,

is disposed outside the tank 11. As shown in Fig. 2, the

other end 14b of the unloading pipe 14 is provided with the

connection portion 14j to the outside of the ship. The

connection portion 14j has, for example, a flange or the

like, and is disposed toward one (for example, the side 3A)

of the sides 3A and 3B. The opening of a connection portion

14j is normally blocked by a lid (not shown). By removing

the lid (not shown) of the connection portion 14j, it is

possible to connect the end portion of the connection pipe

50 for connection to a facility side tank 101 of the external

facility 100 in place of the lid (not shown).

[00201

As shown in Fig. 4, in a case where the liquefied

carbon dioxide L is loaded into the tank 11 from the external

facility 100, the connection pipe 50 connects and allows a

facility side pipe 102 provided in the facility side tank

101 of the external facility 100 and the connection portion

13j of the loading pipe 13 to communicate with each other.

In addition, in a case where the liquefied carbon dioxide L

is unloaded from the tank 11 to the external facility 100,

the connection pipe 50 connects and allows the facility side

pipe 102 provided in the facility side tank 101 of the

external facility 100 and the connection portion 14j of the

unloading pipe 14 to communicate with each other. In the

following description, except for the case where the loading

pipe 13 and the unloading pipe 14 are distinguished, the

loading pipe 13 and the unloading pipe 14 are simply

referred to as pipes 12, and the connection portions 13j

and 14j are simply referred to as connection portions 12j.

[0021]

Opening-closing valves 15 and 105 are provided on the

pipe 12 and the facility side pipe 102 on the external

facility 100 side, respectively. The opening-closing valve

opens and closes a flow channel in the pipe 12. The

opening-closing valve 105 opens and closes a flow channel

in the facility side pipe 102. In addition, an opening valve 106 is provided in the facility side pipe 102. When the opening valve 106 is opened, the flow channel inside the facility side pipe 102 and the outside communicate with each other. When the opening-closing valves 15 and 105 are closed in a state where the facility side pipe 102 and the pipe 12 are connected to each other by the connection pipe

50, the inside of the pipe 12, the connection pipe 50, and

the facility side pipe 102 positioned between the opening

closing valve 15 and the opening-closing valve 105 is not

communicated with the facility side tank 101 or the tank 11.

Here, the outside to which the flow channel in the facility

side pipe 102 is communicated is not limited to the

atmosphere. For example, a container such as a tank capable

of storing the gas discharged through the opening valve 106

may be adopted.

[0022]

As shown in Fig. 2, the replacement gas supply unit 20

feeds a replacement gas Ga into the pipe 12 and the

connection pipe 50 in a state where the connection pipe 50

for connection to the external facility 100 is connected to

the pipe 12. As the replacement gas Ga, a gas that does

not cause a chemical reaction with carbon dioxide is used.

The moisture content of the replacement gas Ga is adjusted

to be equal to or less than a predetermined upper limit

value. As the replacement gas Ga, air having the moisture content adjusted to be equal to or less than a predetermined upper limit value (so-called dry air) or an inert gas such as nitrogen or argon can be used. In this embodiment, dry air is used as the replacement gas Ga. The replacement gas supply unit 20 includes an air dryer 21. The air dryer 21 removes moisture from the atmosphere taken in from the outside to form dry air having the moisture content adjusted to be equal to or less than a predetermined upper limit value, for example, a dew point temperature of -40°C. The air dryer 21 is connected to the pipe 12 via a replacement gas supply pipe 22. An opening-closing valve 23 is provided in the replacement gas supply pipe 22. The dry air formed by the air dryer 21 is fed to the inside of the pipe 12, the connection pipe 50, and the facility side pipe 102 through the replacement gas supply pipe 22 by opening the opening-closing valve 23. The upper limit value of the moisture content in the dry air may be any value as long as the moisture in the pipe can be efficiently removed, and can be obtained in advance by an experiment or the like.

[00231

As shown in Figs. 2 and 4, the carbon dioxide supply

unit 30 feeds a carbon dioxide gas Gc into the pipe 12, the

connection pipe 50, and the facility side pipe 102 in a

state where the connection pipe 50 for connection to the

external facility 100 is connected to the pipe 12. In this embodiment, the carbon dioxide supply unit 30 uses the boil off gas formed by the vaporization of the liquefied carbon dioxide L in the tank 11 as the carbon dioxide gas Gc. The carbon dioxide supply unit 30 includes a boil-off gas supply pipe 31 (refer to Figs. 2 and 3). The boil-off gas supply pipe 31 allows the gas phase in the upper portion in the tank 11 and the pipe 12 to communicate with each other. The carbon dioxide supply unit 30 feeds the boil-off gas from the tank 11 to the inside of the connection pipe 50 and the facility side pipe 102 through the pipe 12.

[00241

(Procedure of Method for Transferring Liquefied Carbon

Dioxide)

As shown in Fig. 5, a method S10 for transferring the

liquefied carbon dioxide L according to this embodiment

includes a step Sl of connecting the connection pipe 50, a

step S12 of replacing with the replacement gas Ga, a step

S13 of replacing with the carbon dioxide gas Gc, and a step

S14 of transferring the liquefied carbon dioxide L.

[0025]

In the step Sl of connecting the connection pipe 50,

as shown in Fig. 6, one end of the connection pipe 50 for

connection to the external facility 100 is connected to the

pipe 12. Further, the other end of the connection pipe 50

is connected to the facility side pipe 102 of the external facility 100. At this time, the opening-closing valves 15,

23, and 105, and the opening valve 106 are kept in the

closed state. In this state, air is contained in the pipe

12, the connection pipe 50, and the facility side pipe 102

positioned between the opening-closing valve 15 and the

opening-closing valve 105.

[0026]

In the step S12 of replacing with the replacement gas

Ga, as shown in Fig. 7, the replacement gas Ga is fed into

the inside of the connection pipe 50 by the replacement gas

supply unit 20. To this end, the air dryer 21 is operated,

and the opening-closing valves 15 and 105 are closed, and

the opening-closing valves 23 and the opening valves 106

are opened. By removing the moisture in the air (atmosphere)

taken in from the outside by the air dryer 21, dry air

having the moisture content adjusted to be equal to or less

than a predetermined upper limit value is formed, and the

dry air becomes the replacement gas Ga. The replacement

gas Ga is supplied to the connection portion 12j of the pipe

12 through the replacement gas supply pipe 22. The supplied

replacement gas Ga flows from the pipe 12 to the connection

pipe 50 and the facility side pipe 102, and sequentially

pushes the air inside the pipe 12, the connection pipe 50,

and the facility side pipe 102 to the outside from the

opening valve 106. The dew point of the air discharged from the opening valve 106 is measured, and the replacement gas

Ga is continuously fed until the dew point falls within the

preset allowable value range. When the measured dew point

falls within the allowable value range, the feeding of the

replacement gas Ga by the replacement gas supply unit 20 is

stopped, and the opening valve 106 and the opening-closing

valve 23 are closed. As a result, the inside of the pipe

12, the connection pipe 50, and the facility side pipe 102

between the opening-closing valves 15 and 105 is replaced

with the replacement gas Ga.

[00271

In the step S13 of replacing with the carbon dioxide

gas Gc, the inside of the connection pipe 50 is replaced

with the carbon dioxide gas Gc from the replacement gas Ga.

To this end, as shown in Fig. 8, the opening-closing valves

and 105 are opened, and the opening valve 106 and the

opening-closing valve 23 are closed. In this state, the

boil-off gas of the tank 11 is fed as the carbon dioxide

gas Gc to the inside of the connection pipe 50 and the

facility side pipe 102 through the carbon dioxide supply

unit 30 and the pipe 12. As a result, the replacement gas

Ga (dry air) inside the pipe 12, the connection pipe 50,

and the facility side pipe 102 is sequentially pushed out

to the external facility 100 side. On the external facility

100 side, the carbon dioxide concentration of the air-fuel mixture of the replacement gas Ga and the carbon dioxide gas Gc extruded from the connection pipe 50 side is measured.

When the measured carbon dioxide concentration falls within

the preset concentration range, the carbon dioxide supply

unit 30 stops the supply of the carbon dioxide gas Gc.

[0028]

In the step S14 of transferring the liquefied carbon

dioxide L, as shown in Fig. 9, the liquefied carbon dioxide

L is transferred between the external facility 100 and the

tank 11 through the connection pipe 50 and the pipe 12. For

example, in a case where the liquefied carbon dioxide L is

loaded into the tank 11 from the external facility 100, the

liquefied carbon dioxide L is fed into the tank 11 from the

facility side tank 101 of the external facility 100 through

the facility side pipe 102, the connection pipe 50, and the

pipe 12 (loading pipe 13).

Further, in a case where the liquefied carbon dioxide

L is unloaded from the inside of the tank 11 to the external

facility 100, the liquefied carbon dioxide L is fed into

the facility side tank 101 of the external facility 100 from

the pipe 12 (unloading pipe 14) through the connection pipe

and the facility side pipe 102.

[0029]

(Effects)

According to the method S10 for transferring liquefied carbon dioxide of the above-described embodiment, gas on the inside of the connection pipe 50 and the pipe 12 is replaced with the replacement gas Ga and then further replaced with the carbon dioxide gas Gc. The moisture content of the replacement gas Ga is adjusted to be equal to or less than a predetermined upper limit value.

Accordingly, when the replacement gas Ga is replaced with

the carbon dioxide gas Gc, the reaction between the carbon

dioxide gas Gc and the moisture is suppressed. After

replacing the inside of the connection pipe 50 and the pipe

12 with the carbon dioxide gas Gc, the liquefied carbon

dioxide L transferred between the external facility 100 and

the tank 11 flows to the inside of the connection pipe 50

and the pipe 12, and thus, even at this time, the occurrence

of the reaction between the carbon dioxide gas Gc and the

moisture is suppressed. Therefore, it is possible to

suppress the reaction between the carbon dioxide and the

moisture when the liquefied carbon dioxide L is transferred,

and to suppress the occurrence of corrosion inside the tank

11 or the pipe 12.

[00301

Further, the replacement gas Ga is dry air having the

moisture content adjusted to be equal to or less than a

predetermined upper limit value. The dry air used as the

replacement gas Ga can be formed by drying the air

(atmosphere) with the air dryer 21. Therefore, it is

possible to easily prepare the dry air on the ship 1.

[0031]

Further, the carbon dioxide gas Gc is a boil-off gas

formed by vaporization of the liquefied carbon dioxide L

stored in the tank 11. Accordingly, the carbon dioxide gas

Gc can be easily obtained on the ship 1.

[00321

In the ship 1 of the above-described embodiment, in a

case where the connection pipe 50 for connection to the

external facility 100 is connected to the pipe 12, the

replacement gas supply unit 20 feeds the replacement gas Ga

having the moisture content adjusted to be equal to or less

than a predetermined upper limit value into the connection

pipe 50 and the pipe 12. Accordingly, the inside of the

connection pipe 50 and the pipe 12 can be replaced with the

replacement gas Ga. Further, the carbon dioxide supply unit

feeds the carbon dioxide gas Gc to the inside of the

connection pipe 50 and the pipe 12, and thus the replacement

gas Ga can be replaced with the carbon dioxide gas Gc on

the inside of the connection pipe 50 and the pipe 12. After

that, the liquefied carbon dioxide L is transferred between

the external facility 100 and the tank 11 through the

connection pipe 50 and the pipe 12, and accordingly, it is

possible to suppress the reaction between the carbon dioxide and the moisture when the liquefied carbon dioxide L is transferred, and to suppress the occurrence of corrosion inside the tank 11 or the pipe 12.

[00331

In addition, the ship 1 includes the air dryer 21.

Accordingly, by drying the atmosphere (air) taken in from

the outside by the air dryer 21, it is possible to provide

the dry air having the moisture content adjusted to be equal

to or less than a predetermined upper limit value as the

replacement gas Ga. Accordingly, on the ship 1, it becomes

possible to easily obtain the replacement gas Ga having the

moisture content adjusted to be equal to or less than a

predetermined upper limit value.

[00341

In addition, the ship 1 feeds the boil-off gas formed

by the vaporization of the liquefied carbon dioxide L stored

in the tank 11 into the pipe 12 and the connection pipe 50

as the carbon dioxide gas Gc. Accordingly, the carbon

dioxide gas Gc can be easily obtained on the ship 1.

[00351

(Other Embodiments)

Above, the embodiments of the present disclosure have

been described in detail with reference to the drawings,

but the specific configuration is not limited to the

embodiments, and includes design changes and the like within a scope not departing from the gist of the present disclosure.

In the above embodiment, as the connection portion 12j

of the pipe 12, the connection portion 13j of the loading

pipe 13 and the connection portion 14j of the unloading pipe

14 are individually provided, but the present disclosure is

not limited thereto. For example, the loading pipe 13 and

the unloading pipe 14 may be connected to one pipe 12 on

the other end 13b and 14b sides, and the connection portion

12j may be shared by the loading pipe 13 and the unloading

pipe 14.

[00361

Further, in the above-described embodiment, the

liquefied carbon dioxide L is transferred between the ship

1 and the external facility 100 installed on land, but the

present disclosure is not limited thereto. The liquefied

carbon dioxide L may be transferred between the ship 1 and

an offshore floating structure facility that is disposed

offshore and does not include a propulsion mechanism. In

this case, the offshore floating structure facility

corresponds to the external facility 100 as viewed from the

ship 1.

[00371

In the above embodiment, as the carbon dioxide gas Gc,

a boil-off gas formed by vaporization of the liquefied carbon dioxide L in the tank 11 is used. However, other than the boil-off gas, the carbon dioxide gas Gc may be, for example, a carbon dioxide gas accommodated in another container on the same ship or on the outside of the ship.

Further, in the ship 1 of the above embodiment, the

configuration is provided with two tanks 11, but the number

and arrangement of the tanks 11 are not limited thereto.

Three or more tanks 11 may be provided. Further, in the

above embodiment, a case where the plurality of tanks 11

are disposed side by side in the stem-stern direction Da

has been shown. However, the tanks 11 may be disposed side

by side in the ship width direction (in other words, the

left-right side direction). In addition, in the above

embodiment, the ship 1 is exemplified as the floating

structure, but the present disclosure is not limited thereto.

The floating structure may be an offshore floating structure

facility that does not include a propulsion mechanism. In

a case where the floating structure is an offshore floating

structure facility, the external facility 100 viewed from

the offshore floating structure facility may be a ship.

[00381

The method S10 for transferring the liquefied carbon

dioxide L and the floating structure 1 described in each of

the embodiments are ascertained as follows, for example.

[00391

(1) According to a first aspect, there is provided a

method S10 for transferring the liquefied carbon dioxide L

including: the step Sl of connecting the connection pipe

for connection to the external facility 100 disposed

outside the floating structure 1 to the pipe 12

communicating with the inside of the tank 11 provided in

the floating structure 1; the step S12 of feeding the

replacement gas Ga having the moisture content adjusted to

be equal to or less than a predetermined upper limit value

into the connection pipe 50 and the pipe 12, and replacing

the inside of the connection pipe 50 and the pipe 12 with

the replacement gas Ga; the step S13 of replacing the

replacement gas Ga inside the connection pipe 50 and the

pipe 12 with the carbon dioxide gas Gc; and the step S14 of

transferring the liquefied carbon dioxide L between the

external facility 100 and the tank 11 through the connection

pipe 50 and the pipe 12.

Examples of the floating structure 1 include a ship

and an offshore floating structure facility. Examples of

the floating main structure 2 include the floating main

structure 2 of a hull or an offshore floating structure

facility.

Examples of the replacement gas Ga include dry air and

an inert gas.

[00401

According to this method S10 for transferring

liquefied carbon dioxide L, gas on the inside of the

connection pipe 50 and the pipe 12 is replaced with the

replacement gas Ga and then further replaced with the carbon

dioxide gas Gc. Since the moisture content of the

replacement gas Ga is adjusted to be equal to or less than

a predetermined upper limit value, the reaction between the

carbon dioxide and the moisture is suppressed when the

replacement gas Ga is replaced with the carbon dioxide gas

Gc. After replacing the inside of the connection pipe 50

and the pipe 12 with the carbon dioxide gas Gc, the liquefied

carbon dioxide L transferred between the external facility

100 and the tank 11 flows into the connection pipe 50 and

the pipe 12, and thus, even at this time, the occurrence of

the reaction between the carbon dioxide and the moisture is

suppressed. Therefore, it is possible to suppress the

reaction between the carbon dioxide and the moisture when

the liquefied carbon dioxide L is transferred, and to

suppress the occurrence of corrosion inside the tank 11 or

the pipe 12.

[0041]

(2) In the method S10 for transferring the liquefied

carbon dioxide L according to a second aspect, which is the

method S10 for transferring the liquefied carbon dioxide L of (1), the replacement gas Ga is dry air having a moisture content adjusted to be equal to or less than a predetermined upper limit value.

[00421

Accordingly, the dry air used as the replacement gas

Ga can be formed by drying the air (atmosphere) with the

air dryer. Therefore, it is possible to easily prepare the

dry air on the floating structure 1.

[0043]

(3) In the method S10 for transferring the liquefied

carbon dioxide L according to a third aspect, which is the

method S10 for transferring the liquefied carbon dioxide L

of (1) or (2), the carbon dioxide gas Gc is a boil-off gas

formed by vaporization of the liquefied carbon dioxide L

stored in the tank 11.

[0044]

Accordingly, the carbon dioxide gas Gc can be easily

obtained on the floating structure 1.

[0045]

(4) According to a fourth aspect, there is provided

the floating structure 1 including: the floating main

structure 2; the tank 11 disposed in the floating main

structure 2 and capable of storing the liquefied carbon

dioxide L; the pipe 12 which communicates with the inside

of the tank 11 and to which the connection pipe 50 for supplying the liquefied carbon dioxide L between the external facility 100 and the tank 11 is connectable; the replacement gas supply unit 20 that feeds the replacement gas Ga having a moisture content adjusted to be equal to or less than a predetermined upper limit value into the pipe

12 and the connection pipe 50 in a case where the connection

pipe 50 is connected to the pipe 12; and the carbon dioxide

supply unit 30 that feeds the carbon dioxide gas Gc into

the pipe 12 and the connection pipe 50.

[0046]

In the floating structure 1, the replacement gas

supply unit 20 feeds the replacement gas Ga having the

moisture content adjusted to be equal to or less than a

predetermined upper limit value into the connection pipe 50

and the pipe 12, and accordingly, the gas on the inside of

the connection pipe 50 and the pipe 12 can be replaced with

the replacement gas Ga. Further, the carbon dioxide supply

unit 30 feeds the carbon dioxide gas Gc to the inside of

the connection pipe 50 and the pipe 12, and thus the

replacement gas Ga can be replaced with the carbon dioxide

gas Gc on the inside of the connection pipe 50 and the pipe

12. After that, the liquefied carbon dioxide L is

transferred between the external facility 100 and the tank

11 through the connection pipe 50 and the pipe 12, and

accordingly, it is possible to suppress the reaction between the carbon dioxide and the moisture when the liquefied carbon dioxide L is transferred, and to suppress the occurrence of corrosion inside the tank 11 or the pipe 12.

[0047]

(5) In the floating structure 1 according to a fifth

aspect, which is the floating structure 1 of (4), the

replacement gas supply unit 20 includes the air dryer 21

that reduces an amount of moisture contained in the

atmosphere taken in from the outside.

[0048]

Accordingly, the air dryer 21 reduces the moisture

content in the atmosphere taken in from the outside, and

accordingly, the dry air can be provided as the replacement

gas Ga having the moisture content adjusted to be equal to

or less than a predetermined upper limit value.

[0049]

(6) In the floating structure 1 according to a sixth

aspect, which is the floating structure 1 of (4) or (5),

the carbon dioxide supply unit 30 feeds the boil-off gas

formed by vaporization of the liquefied carbon dioxide L

stored in the tank 11 into the pipe 12 and the connection

pipe 50 as the carbon dioxide gas Gc.

[0050]

Accordingly, by using the boil-off gas as the carbon

dioxide gas Gc, the carbon dioxide gas Gc can be easily obtained on the floating structure 1.

Industrial Applicability

[0051]

According to the method for transferring liquefied

carbon dioxide and the floating structure according to the

present disclosure, it is possible to suppress the reaction

between the carbon dioxide and the moisture when the

liquefied carbon dioxide is transferred, and to suppress

the occurrence of corrosion inside the tank or the pipe.

Reference Signs List

[0052]

While various embodiments of the present invention

have been described above, it should be understood that they

have been presented by way of example only, and not by way

of limitation. It will be apparent to a person skilled in

the relevant art that various changes in form and detail

can be made therein without departing from the spirit and

scope of the invention. Thus, the present invention should

not be limited by any of the above described exemplary

embodiments.

[0053]

Throughout this specification and the claims which

follow, unless the context requires otherwise, the word

"comprise", and variations such as "comprises" and

"comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

[0054]

The reference in this specification to any prior

publication (or information derived from it), or to any

matter which is known, is not, and should not be taken as an

acknowledgment or admission or any form of suggestion that

that prior publication (or information derived from it) or

known matter forms part of the common general knowledge in

the field of endeavour to which this specification relates.

[0055]

1: Ship (floating structure)

2: Hull (floating main structure)

2a: Stem

2b: Stern

3A, 3B: Side

4: Bottom

5: Upper deck

7: Superstructure

8: Cargo tank storage compartment

10: Tank facility

11: Tank

12: Pipe

12j: Connection portion

13: Loading pipe

13a: One end

13b: Other end

13j: Connection portion

14: Unloading pipe

14a: One end

14b: Other end

14j: Connection portion

15: Opening-closing valve

20: Replacement gas supply unit

21: Air dryer

22: Replacement gas supply pipe

23: Opening-closing valve

30: Carbon dioxide supply unit

50: Connection pipe

100: External facility

101: Facility side tank

102: Facility side pipe

105: Opening-closing valve

106: Opening valve

Ga: Replacement gas

Gc: Carbon dioxide gas

L: Liquefied carbon dioxide

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

[Claim 1]

A method for transferring liquefied carbon dioxide

comprising:

a step of connecting a connection pipe for connection

to an external facility disposed outside a floating

structure, to a pipe communicating with an inside of a tank

provided in the floating structure;

a step of feeding a replacement gas having a moisture

content adjusted to be equal to or less than a predetermined

upper limit value into the connection pipe and the pipe,

and replacing an inside of the connection pipe and the pipe

with the replacement gas;

a step of replacing the replacement gas inside the

connection pipe and the pipe with a carbon dioxide gas; and

a step of transferring liquefied carbon dioxide

between the external facility and the tank through the

connection pipe and the pipe.
[Claim 2]

The method for transferring liquefied carbon dioxide

according to Claim 1, wherein

the replacement gas is dry air having a moisture

content adjusted to be equal to or less than a predetermined upper limit value.
[Claim 3]

The method for transferring liquefied carbon dioxide

according to Claim 1 or 2, wherein

the carbon dioxide gas is a boil-off gas formed by

vaporization of liquefied carbon dioxide stored in the tank.
[Claim 4]

A floating structure comprising:

a floating main structure;

a tank disposed in the floating main structure and

capable of storing liquefied carbon dioxide;

a pipe which communicates with an inside of the tank

and to which a connection pipe for supplying liquefied

carbon dioxide between an external facility and the tank is

connectable;

a replacement gas supply unit that feeds a replacement

gas having a moisture content adjusted to be equal to or

less than a predetermined upper limit value into the pipe

and the connection pipe in a case where the connection pipe

is connected to the pipe; and

a carbon dioxide supply unit that feeds a carbon

dioxide gas into the pipe and the connection pipe, wherein

the replacement gas supply unit comprises an air dryer that reduces an amount of moisture contained in an atmosphere taken in from an outside.
[Claim 5]

The floating structure according to Claim 4, wherein

the carbon dioxide supply unit feeds a boil-off gas

formed by vaporization of liquefied carbon dioxide stored

in the tank into the pipe and the connection pipe as the

carbon dioxide gas.