KR102119971B1 - ethan treatment system and ethan carrier - Google Patents

Abstract

The present invention relates to an ethane treatment system and an ethane carrier, an ethane treatment system provided in a multi-cargo type ethane carrier having an ethane storage tank and storing ethane and non-ethane materials in a liquid phase, the liquefied gas of the ethane storage tank An ethane supply unit for supplying the ethane carrier to a high-pressure consumer for propulsion; And an ethane liquefaction unit for re-liquefying the evaporation gas generated in the ethane storage tank and returning it to the ethane storage tank, wherein the ethane supply unit supplies ethane among the ethane and non-ethane substances stored in the liquid to the high-pressure consumer, The ethane liquefaction unit is characterized by re-liquefying both the ethane and non-ethane substances evaporated in the gas phase.

Description

Ethan treatment system and ethan carrier

The present invention relates to an ethane treatment system and an ethane carrier.

As environmental regulations have recently been strengthened, the use of gaseous fuels such as LNG and LPG, which are close to eco-friendly fuels, is being replaced by replacing existing liquid fuels such as gasoline and diesel.

The gaseous fuel is transported through a gas carrier provided to transport a specific gas, and the gaseous fuel is stored in a tank in a reduced volume as it is liquefied at a low temperature to increase storage efficiency.

The tank for storing gas fuel is mounted inside the gas carrier, and a plurality of tanks are provided in the front-rear direction of the gas carrier. In addition, the gas fuel storage tank may be provided with various insulating structures to maintain the liquid state of the gas fuel.

However, the insulated structure cannot completely block the heat penetration from the outside, and the gas fuel stored in the gas fuel storage tank naturally evaporates to generate evaporation gas, and the evaporation gas is a factor that increases the internal pressure of the gas fuel storage tank. do.

Since the gas fuel storage tank has a limit value of internal pressure depending on the structure, when the internal pressure rises as the evaporation gas is continuously generated, the emission of the evaporation gas is realized, and the emitted evaporation gas is consumed as fuel or re-liquefied. It is returned to the fuel storage tank.

In addition, the gas carrier may use liquefied gas stored in a gas fuel storage tank as fuel. That is, the gas carrier is provided to liquefy and return the boil-off gas of the gas fuel storage tank, and to consume the liquefied gas as fuel.

The gas fuel processing structure is very actively developed and manufactured in the LNG field. However, the structure of treating liquefied gas or evaporated gas for ethane other than LNG is currently in a state of no performance.

However, considering the reality that consumption of ethane is increasing, it is urgent to realize the configuration of processing gaseous fuel for the ethane carrier.

The present invention was created to solve the problems of the prior art as described above, and the object of the present invention is to provide an ethane treatment system and an ethane carrier to efficiently treat liquefied gas or evaporation gas of ethane when transporting ethane. It is intended to provide.

An ethane treatment system according to an aspect of the present invention is an ethane treatment system provided on a multi-cargo type ethane carrier having an ethane storage tank and storing ethane and non-ethane materials in a liquid phase, wherein the liquefied gas of the ethane storage tank is the An ethane supply unit that supplies a high-pressure demand source for the promotion of the ethane carrier; And an ethane liquefaction unit for re-liquefying the evaporation gas generated in the ethane storage tank and returning it to the ethane storage tank, wherein the ethane supply unit supplies ethane among the ethane and non-ethane substances stored in the liquid to the high-pressure consumer, The ethane liquefaction unit is characterized by re-liquefying both the ethane and non-ethane substances evaporated in the gas phase.

Specifically, the non-ethane material may be a hydrocarbon other than ethane that exists as a gas at room temperature but is liquefied and stored.

Specifically, the high-pressure consumer is an engine that propels the ethane carrier, and the ethane supply unit can supply only the ethane among the ethane and non-ethane substances stored in the liquid phase to the engine.

Specifically, the ethane supply unit, a high pressure pump to pressurize the liquefied gas discharged from the transfer pump in the ethane storage tank; And a high-pressure vaporizer that heats the pressurized liquefied gas and supplies it to the high-pressure consumer.

Specifically, the ethane supply unit may further include a low pressure vaporizer that heats the liquefied gas discharged from the ethane storage tank and supplies it to a low pressure demand source for power generation.

Specifically, the high-pressure vaporizer and the low-pressure vaporizer can be supplied to the high-pressure demand or the low-pressure demand by dividing and heating the liquefied gas discharged from the transfer pump in the ethane storage tank.

Specifically, the ethane liquefaction unit, an evaporation gas compressor for compressing the evaporation gas generated in the ethane storage tank; And a liquefier that liquefies the compressed boil-off gas by heat exchange with a refrigerant.

Specifically, the boil-off gas compressor can compress the boil-off gas generated in the ethane storage tank and supply it to a low-pressure consumer for power generation.

Specifically, the boil-off gas compressor is composed of multiple stages, the discharge pressure of the boil-off gas compressor at the last stage is provided as the required pressure of the liquefier, and the boil-off gas compressor in the middle stage or the boil-off gas compressor in the last stage. The compressed boil-off gas can be supplied to the low-pressure consumer.

Specifically, the ethane liquefaction unit, a first evaporation gas supply line for supplying the evaporation gas compressed by the evaporation gas compressor in the middle stage to the low pressure demand; And a second boil-off gas supply line that supplies the boil-off gas compressed by the boil-off gas compressor at the last stage to the low-pressure consumer.

Specifically, the first boil-off gas supply line and the first boil-off gas supply line may be joined and connected to the low-pressure demand source.

Specifically, the flow rates of the first boil-off gas supply line and the first boil-off gas supply line may be adjusted according to the load of the low-pressure consumer.

An ethane carrier according to an aspect of the present invention is characterized by having the ethane treatment system.

The ethane treatment system and the ethane carrier according to the present invention can realize the ethane treatment configuration for the ethane carrier by efficiently treating the ethane liquefied gas or naturally occurring ethane evaporation gas stored when loading ethane.

1 is a conceptual diagram of an ethane carrier according to an embodiment of the present invention.
2 is a conceptual diagram of an ethane treatment system according to an embodiment of the present invention.

The objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments associated with the accompanying drawings. It should be noted that in this specification, when adding reference numerals to the components of each drawing, the same components have the same number as possible even though they are displayed on different drawings. In addition, in the description of the present invention, when it is determined that detailed descriptions of related known technologies may unnecessarily obscure the subject matter of the present invention, detailed descriptions thereof will be omitted.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Hereinafter, liquefied gas means liquefied ethane for storage (including forced vaporization after storage), and evaporated gas means generated by natural vaporization of stored liquid ethane (including liquefied). That is, the liquefied gas and the boil-off gas are hereinafter classified only according to the state in the ethane storage tank, but it is not necessarily limited to the liquid state or the gas state.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a conceptual diagram of an ethane carrier according to an embodiment of the present invention, and FIG. 2 is a conceptual diagram of an ethane treatment system according to an embodiment of the present invention.

Hereinafter, the ethane treatment system 1 of the present invention will be described with reference to FIG. 2 in particular, and the present invention includes an ethane carrier line S having an ethane treatment system 1 as shown in FIG. 1.

At this time, the ethane carrier S is not limited to an ethane carrier, and means a ship provided with at least one ethane storage tank 10 for loading ethane. That is, the ethane carrier S of the present invention can transport ethane alone or propane, butane, ethylene, and the like along with ethane.

Therefore, the ethane carrier (S) in the present invention has a ethane storage tank (10) and materials other than ethane and ethane (existing as a gas at room temperature but liquefied and stored as a hydrocarbon such as propane, referred to as a non-ethane material) Refers to a multi-cargo type ethane carrier (S) that is stored in a liquid state.

Since the demand for ethane is relatively small compared to LNG used for gas carriers exclusively loaded for LNG or LPG, ethane carriers (S) for loading non-ethane materials together are used rather than exclusively for ethane. .

Of course, considering that the demand for ethane may increase, the ethane carrier (S) of the present invention may include only an ethane storage tank (10) to cover a carrier for exclusively loading ethane.

Hereinafter, the ethane treatment system 1 provided on the ethane carrier S will be described with reference to FIG. 2.

Referring to FIG. 2, the ethane treatment system 1 according to an embodiment of the present invention includes an ethane storage tank 10, an ethane supply unit 20, and an ethane liquefaction unit 30.

The ethane storage tank 10 is mounted on a multi-cargo type ethane carrier (S) and may have an insulating structure to store ethane in a liquid state. However, in spite of the heat insulation structure, liquid ethane (liquefied gas) may naturally evaporate due to external heat permeation, thereby generating gaseous ethane (evaporation gas).

The liquefied gas may be processed by the ethane supply unit 20 described below, and the evaporated gas may be processed by the ethane liquefaction unit 30 described below. Of course, the treatment of liquefied gas or evaporated gas is not limited to the above configuration.

The ethane storage tank 10 may be provided at various locations within the ethane carrier (S). That is, the ethane carrier (S) is provided with one or more cargo tanks 10 and 10a, at least one of which is used as an ethane storage tank 10, and specific cargo tanks 10 and 10a are dedicated to ethane. It may not be limited.

However, in order to convert the cargo tank 10a, which was loaded with non-ethane materials, into the ethane storage tank 10, the inside may be emptied and processed to allow loading of ethane.

Also, the ethane storage tank 10 is not limited in shape or structure. For example, the ethane storage tank 10 may be a membrane-type tank, and of course, a stand-alone or pressurized tank.

A transfer pump 11 may be provided inside the ethane storage tank 10. The transfer pump 11 is installed on the floor inside the ethane storage tank 10 to pump liquefied gas and discharge it to the outside of the ethane storage tank 10. At this time, the liquefied gas discharged from the transfer pump 11 flows along the liquefied gas supply line L20.

The ethane supply unit 20 supplies the liquefied gas of the ethane storage tank 10 to the high-pressure demand destination 40 for the propulsion of the ethane carrier S. At this time, the high-pressure consumer 40 may be an engine that propels the ethane carrier S, and may be ME-LGI, ME-GIE, etc., which are propulsions that consume ethane, similar to ME-GI engines that are propulsed with LNG.

When the high pressure demand destination 40 is ME-GIE, the required pressure may be about 380 bar, but the required pressure of the high pressure demand destination 40 is not limited to the above, and high pressure may mean 15 bar or more, for example.

The ethane supply unit 20 includes a high pressure pump 21 and a high pressure vaporizer 22. The high pressure pump 21 may pressurize the liquefied gas discharged from the transfer pump 11 in the ethane storage tank 10 to a level corresponding to the required pressure of the high pressure demand destination 40.

The high pressure vaporizer 22 can heat the liquefied gas pressurized by the high pressure pump 21 and supply it to the high pressure demand destination 40. However, when the high-pressure consumer 40 is ME-LGI receiving gaseous fuel in the liquid phase, the high-pressure vaporizer 22 may be omitted.

The high pressure pump 21 and the high pressure vaporizer 22 are provided on the liquefied gas supply line L20 through which liquefied gas discharged from the transfer pump 11 flows, and the liquefied gas supply line L20 is an ethane storage tank. It can be connected from (10) to the high-pressure consumer (40).

However, in the ethane carrier S, in addition to the high-pressure demand destination 40 for propulsion, a low-pressure demand destination 41 for power generation may also be provided, and the low-pressure demand destination 41 is a DFG to which the generator 41a is connected, and thus has a required pressure. It can be around 10 bar. For reference, the power generated by the generator 41a may be distributed to operating mechanisms (high pressure pump 21, evaporative gas compressor 31, refrigerant compressor 321, etc.) described in this embodiment.

In this embodiment, a configuration for supplying liquefied gas to the high-pressure demand destination 40 can be minimized by utilizing a configuration for supplying the liquefied gas to the high-pressure demand destination 40. That is, the ethane supply unit 20, the liquefied gas discharged from the transfer pump 11 in the ethane storage tank 10 is to be branched supply to the high pressure demand destination 40 and the low pressure demand destination 41, the discharge of the transfer pump 11 The pressure is made to correspond to the required pressure of the low pressure demand destination 41.

Through this, the present embodiment can supply the liquefied gas discharged from the ethane storage tank 10 to the low-pressure demand source 41 without additional pressure.

The liquefied gas pressurized to the required pressure of the low pressure demand destination 41 by the transfer pump 11 is supplied to the low pressure demand destination 41 via the low pressure vaporizer 23. At this time, the low pressure vaporizer 23 heats the liquefied gas discharged from the ethane storage tank 10 and supplies it to the low pressure demand destination 41 for power generation, and supplies it at a low pressure between the low pressure vaporizer 23 and the low pressure demand destination 41. A valve unit for adjusting the flow rate of liquefied gas is provided. Of course, although not described above, a valve train for adjusting the flow rate may be provided between the high-pressure vaporizer 22 and the high-pressure consumer 40.

The high-pressure vaporizer 22 and the low-pressure vaporizer 23 can be supplied by dividing and heating liquefied gas discharged from the transfer pump 11 in the ethane storage tank 10 to supply it to the high-pressure demand destination 40 or the low-pressure demand demand 41. have. In this case, the high pressure demand destination 40 and the low pressure demand destination 41 share the transfer pump 11, and the low pressure demand destination 41 can omit the additional pressurization means, thereby simplifying the configuration.

The liquefied gas branching line L21 may be branched to the liquefied gas supply line L20 that transfers the liquefied gas discharged from the transfer pump 11 to the high-pressure demand destination 40, and the liquefied gas branching line L21 is liquefied gas. Branch valve V21 is provided.

The liquefied gas branch valve V21 may branch a flow rate corresponding to the required flow rate of the low-pressure demand source 41 from the liquefied gas discharged to the transfer pump 11. However, the low pressure demand destination 41 is for power generation and the high pressure demand destination 40 is for propulsion, and propulsion should take precedence over power generation.

Therefore, the liquefied gas branch valve V21 allows the liquefied gas discharged from the transfer pump 11 to meet the required flow rate of the high pressure demand destination 40, but can only deliver excess flow to the low pressure demand destination 41. In order to open the liquefied gas branch valve V21, the opening degree may be adjusted based on information such as the load of the transfer pump 11, the discharge flow rate, the load of the high-pressure demand destination 40, and the required flow rate.

The ethane supply unit 20 including these components may be provided to supply only ethane among the ethane and non-ethane materials stored in the liquid phase in the ethane carrier S to the high-pressure demand source 40 or the low-pressure demand source 41. That is, the ethane carrier S may not be dedicated to ethane, but the ethane supply 20 is provided exclusively for ethane.

However, the high-pressure demand destination 40 or the low-pressure demand destination 41 is provided as a heterogeneous fuel engine that uses liquid fuel at room temperature such as ethane or diesel, and means for supplying diesel, etc. are separately provided. It may be supplied to the high-pressure consumer 40 or the like, and non-ethane materials may be stored without being supplied.

The ethane liquefaction unit 30 re-liquefies the evaporation gas generated in the ethane storage tank 10 and returns it to the ethane storage tank 10. The ethane liquefaction unit 30 includes an evaporative gas compressor 31 and a liquefier 32.

The evaporation gas compressor 31 compresses the evaporation gas generated in the ethane storage tank 10. At this time, the discharge pressure of the ethane storage tank 10 may be a pressure suitable for the liquefier 32, and may be around 24 bar higher than the required pressure of the low pressure demand source 41.

The evaporative gas compressor 31 is provided in multiple stages, and may be provided in three or more stages as shown in the drawing. At this time, the discharge pressure of the two-stage evaporation gas compressor (31) may be about 10.5 bar, which is the same/similar to the required pressure of the low-pressure consumer (41), and the present invention utilizes this point to partially compress the evaporation gas compressor (31). The evaporated gas can be supplied to the low pressure demand source 41 for use. This will be described below.

In the ethane storage tank 10, an liquefied gas liquefaction line L30 is provided to the liquefier 32, and an evaporated gas compressor 31 is arranged in multiple stages in the liquefied gas liquefaction line L30. At this time, the discharge pressure of the last stage evaporation gas compressor 31 is provided as the required pressure of the liquefier 32, and the discharge pressure of the middle stage (e.g., two stages) evaporation gas compressor 31 is a low pressure demand source 41 It is prepared at a level similar to the required pressure.

At this time, in order to supply the boil-off gas compressed by the boil-off gas compressor (31) at the middle stage to the low-pressure demand source (41), downstream of the boil-off gas liquefaction line (L30), the boil-off gas compressor (31) at the middle stage, the first boil-off gas The supply line L31a may be branched.

However, although the discharge pressure of the middle stage evaporation gas compressor 31 is similar to that of the low pressure demand destination 41, in the process of the evaporation gas being transferred to the low pressure demand destination 41 along the first evaporation gas supply line L31a. Pressure loss may occur.

Therefore, in the present embodiment, the evaporation gas discharged from the evaporation gas compressor 31 at the last stage may be additionally used in preparation for a pressure drop. To this end, the second evaporation gas supply line (L31b) is branched from the evaporation gas liquefaction line (L30) to the low pressure demand source (41) downstream of the evaporation gas compressor (31).

The second boil-off gas supply line L31b can supply the boil-off gas compressed by the last boil-off gas compressor 31 to the low-pressure demand source 41. At this time, the first evaporation gas supply line (L31a) and the second evaporation gas supply line (L31b) may be joined and connected to the low-pressure demand source (41).

That is, the present embodiment can supply the compressed boil-off gas from the middle-stage boil-off gas compressor 31 or the last stage boil-off gas compressor 31 to the low-pressure demand source 41, wherein the first boil-off gas supply line L31a ) Is provided with a first evaporation gas supply valve (V31a), a second evaporation gas supply line (L31b) is provided with a second evaporation gas supply valve (V31b), the flow rate of the evaporation gas supplied to the low pressure demand source (41) through opening control Is regulated.

For example, when the load of the low pressure demand destination 41 is high, the opening degree of the second evaporation gas supply valve V31b may be increased and/or the opening degree of the first evaporation gas supply valve V31a may be lowered, and conversely, the low pressure demand destination 41 When the load of) is lowered, the opening degree of the first evaporation gas supply valve V31a may be increased and/or the opening degree of the second evaporation gas supply valve V31b may be lowered.

Of course, the opening and closing of the first and second evaporation gas supply valves V31a and V31b is not limited to the above, and may be variously adjusted according to the load of the low pressure demand source 41.

Through this configuration, this embodiment can compress the boil-off gas generated in the ethane storage tank 10 to the boil-off gas compressor 31 for the liquefier 32 and supply it to the low-pressure demand source 41, thereby reducing cost. It is possible. However, when the liquefier 32 is not operating, the low-pressure demand source 41 can be operated with liquefied gas or diesel.

Of course, unlike the above description, in addition to the evaporator gas compressor 31 for the liquefier 32, an evaporator gas compressor (not shown) for the low-pressure consumer 41 may be separately provided. In this case, the boil-off gas generated in the ethane storage tank 10 may be supplied to the low-pressure demand source 41 via the boil-off gas compressor (and cooler).

Therefore, since some of the evaporation gas generated in the ethane storage tank 10 may be consumed at the low pressure demand source 41, in the above case, the capacity of the liquefier 32 may be reduced.

The liquefier 32 liquefies the compressed boil-off gas by heat exchange with a refrigerant. At this time, the refrigerant may be a mixed refrigerant or nitrogen, but is not particularly limited.

However, the refrigerant may circulate along the refrigerant circulation line (L311) connected to the liquefier 32, and in the process of circulating, the liquefier (32) undergoes compression by the refrigerant compressor (321) and expansion by the refrigerant valve (322). ) Can be liquefied by flowing into a low temperature state.

The refrigerant used in the liquefier 32 is provided to liquefy ethane or the like. That is, the liquefier 32 is provided to liquefy not only the evaporation gas generated from the ethane storage tank 10, but also gaseous hydrocarbons generated from other cargo tanks 10a.

That is, the ethane liquefaction unit 30 can re-liquefy both ethane and non-ethane substances evaporated in the gas phase. This is a difference from the previous ethane supply unit 20. The ethane supply unit 20 is provided to supply only the ethane stored in the liquid to the consumers 40 and 41, while the ethane liquefaction unit 30 is provided to liquefy the ethane and non-ethane substances generated in the gas phase.

At this time, the low-temperature refrigerant flowing into the liquefier 32, the temperature that can liquefy up to the substance having the lowest boiling point (eg, ethane (-94 degrees C) or ethylene (-104 degrees C)) among ethane and non-ethane substances Can have

However, the flow rate, temperature, etc. of the refrigerant flowing into the liquefier 32 may vary depending on what kind of material is introduced into the liquefier 32, which controls the load of the refrigerant compressor 321, the refrigerant valve 322, etc. Can be implemented as

That is, the ethane liquefaction unit 30 of the present embodiment may be provided as a specification capable of liquefying ethane flowing along the evaporation gas liquefaction line L30, and also liquefying non-ethane materials.

This is because, in the case of the ethane carrier (S) of the present invention, it may be a multi-cargo type that loads not only ethane but also other hydrocarbons, and is also a type that can change the type of material loaded in the cargo tanks 10 and 10a with each operation. to be.

For example, the ethane carrier (S) can load ethane, but can also operate in a state where only non-ethane materials are loaded. In this case, the ethane supply unit 20 does not supply liquefied gas to the demand destinations 40 and 41. 40, 41) are operated by diesel or the like.

However, the ethane liquefaction unit 30 can operate by receiving the electric power generated from the generator 41a of the low-pressure demand source 41 operated by diesel or the like, and compresses and liquefies the evaporated gas from which the non-ethane material evaporates, thereby reducing the cargo tank ( 10a).

As described above, in the present embodiment, in the ethane carrier (S) loaded with ethane and non-ethane materials, ethane liquefied gas is supplied to the customers (40, 41), ethane evaporation gas is liquefied, and demand for non-ethane materials ( 40, 41), but can be liquefied and returned. In addition, by simplifying the configuration in the process of supplying or liquefying ethane, the overall efficiency of the system can be greatly improved.

In the above, the present invention has been described based on the embodiments of the present invention, but this is merely an example and does not limit the present invention, and those skilled in the art to which the present invention pertains will not depart from the essential technical content of the present embodiment. It will be appreciated that various combinations or modifications and applications not illustrated in the examples are possible in the scope. Accordingly, technical contents related to modifications and applications that can be easily derived from the embodiments of the present invention should be interpreted as being included in the present invention.

S: ethane carrier 1: ethane treatment system
10: ethane storage tank 11: transfer pump
20: ethane supply 21: high pressure pump
22: high pressure vaporizer 23: low pressure vaporizer
L20: Liquefied gas supply line L21: Liquefied gas branch line
V21: liquefied gas branch valve 30: ethane liquefaction section
31: evaporative gas compressor 32: liquefier
321: refrigerant compressor 322: refrigerant valve
L30: Evaporation gas liquefaction line L31a: First evaporation gas supply line
L31b: Second evaporation gas supply line V31a: First evaporation gas supply valve
V31b: Second evaporation gas supply valve L311: Refrigerant circulation line
40: high pressure demand 41: low pressure demand
41a: generator

Claims (13)

An ethane treatment system provided in a multi-cargo type ethane carrier that stores non-ethane, which is a hydrocarbon other than ethane that exists as a gas at room temperature but is liquefied and has a ethane storage tank in a liquid phase,
An ethane supply unit for supplying liquefied gas from the ethane storage tank to a high-pressure consumer for propulsion of the ethane carrier; And
It includes an ethane liquefaction unit to re-liquefy the evaporation gas generated in the ethane storage tank and return to the ethane storage tank,
The high-pressure consumer is provided with an engine using only ethane among the ethane and the non-ethane materials,
The ethane supply unit is provided exclusively for ethane that supplies only ethane among the ethane and non-ethane materials stored in the liquid to the high-pressure consumer, and the non-ethane material is stored without being supplied.
The ethane liquefaction unit re-liquefies both ethane and non-ethane substances evaporated in the gas phase,
Wherein the high-pressure demand, ethane treatment system characterized in that when the lack of ethane, the liquid fuel is supplied and operated at room temperature. delete delete According to claim 1, The ethane supply unit,
A high pressure pump that pressurizes the liquefied gas discharged from the transfer pump in the ethane storage tank; And
And a high-pressure vaporizer that heats the pressurized liquefied gas and supplies it to the high-pressure consumer. According to claim 4, The ethane supply unit,
An ethane treatment system further comprising a low pressure vaporizer that heats the liquefied gas discharged from the ethane storage tank and supplies it to a low pressure demand source for power generation. The high-pressure vaporizer and the low-pressure vaporizer of claim 5,
The ethane treatment system, characterized in that the liquefied gas discharged from the transfer pump in the ethane storage tank is supplied and heated to be supplied to the high-pressure demand or the low-pressure demand. According to claim 1, The ethane liquefaction unit,
An evaporation gas compressor compressing the evaporation gas generated in the ethane storage tank; And
An ethane treatment system further comprising a liquefier that liquefies the compressed boil-off gas by heat exchange with a refrigerant. The method of claim 7, wherein the boil-off gas compressor,
An ethane treatment system characterized by compressing the evaporation gas generated in the ethane storage tank and supplying it to a low-pressure demand source for power generation. The method of claim 8, wherein the boil-off gas compressor,
Consisting of multiple stages, the discharge pressure of the evaporative gas compressor at the final stage is provided as the required pressure of the liquefier,
An ethane treatment system characterized by supplying the compressed vapor from the middle stage of the boil-off gas compressor or the last stage of the boil-off gas compressor to the low-pressure consumer. 10. The method of claim 9, The ethane liquefaction unit,
A first evaporation gas supply line for supplying the evaporation gas compressed by the evaporation gas compressor at an intermediate stage to the low-pressure consumer; And
An ethane treatment system further comprising a second evaporation gas supply line for supplying the evaporation gas compressed by the evaporation gas compressor at the last stage to the low-pressure consumer. The method of claim 10, wherein the first boil-off gas supply line and the first boil-off gas supply line,
An ethane treatment system, characterized in that it is joined and connected to the low-pressure consumer. The flow rate of the first boil-off gas supply line and the first boil-off gas supply line,
Ethane treatment system characterized in that it is adjusted according to the load of the low-pressure demand destination. An ethane carrier according to any one of claims 1 to 4, characterized in that it has the ethane treatment system.

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