System and method for transfer of liquefied gas from one tank to another
Patent Information
- Application Number
- EP2024701999
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-02-03
- Filing Date
- 2024-01-31
- Publication Date
- 2025-12-10
AI Technical Summary
Existing methods for transferring liquefied gases, such as LCO2, between tanks face challenges in maintaining pressure and preventing contamination, particularly when impurities in the vapor phase from onshore storage tanks are returned to ships, leading to inefficiencies and potential contamination risks.
The system subjects the liquefied gas transfer stream to reduced pressure, separating it into liquid and vapor phases, with the vapor being compressed and returned to the discharging tank, while the subcooled liquid is sent to the receiving tank, eliminating the need for indirect heat transfer and reducing refrigeration requirements.
This approach effectively maintains pressure in both tanks, reduces the risk of contamination, and significantly lowers power requirements by up to 33% compared to prior art, while minimizing the need for refrigeration and equipment.
Smart Images
Figure EP2024052359_08082024_PF_FP
Abstract
Description
[0001] SYSTEM AND METHOD FOR TRANSFER OF LIQUEFIED GAS FROM ONE TANK TO ANOTHER
[0002] FIELD OF THE INVENTION
[0003] The present invention generally relates to transfer of a liquefied gas, such as liquid CO2 (LCO2), from a discharging tank to a receiving tank, and more particularly to a system for offloading liquid LCO2 from an LCO2 carrier ship to an intermediate LCO2 storage tank at an LCO2 receiving terminal connected to a long term LCO2 storage facility, wherein contamination from the receiving tank to the discharging tank is avoided. The invention also relates to a corresponding method. The invention is based on subjecting a liquefied gas transfer stream to a reduced pressure, thereby partly vaporising the transfer stream, separating the stream into a liquid phase and a vapour phase, and forwarding the separated liquid phase having a reduced pressure and temperature to the receiving tank, while the separated vapour is compressed and returned to the discharging tank.
[0004] BACKGROUND ART
[0005] Liquefied gas, such as liquefied natural gas (LNG), and liquid CO2 (LCO2), is frequently being handled, transported, and transferred. In some instances it is desirable to transfer liquefied gas contained in one tank to another tank to another tank.
[0006] Captured and liquefied carbon dioxide can be transported in the liquid phase (LCO2) from various locations and customers to CO2 receiving terminals at which the CO2 will be temporarily stored in intermediate buffer storage tanks onshore, before being pumped in a dense phase via a pipeline and injected into an offshore long-term storage reservoir. The purpose of the buffer storage is to allow for continuous injection to the long-term storage reservoir despite intermittent LCO2 cargo transfer from ship.
[0007] A general description of an outline of a CCS chain can be found in Conceptualization of CO2 Terminal for Offshore CCS Using System Engineering Process by Hyonjeong et al. Energies, 2019, 12, 4350. Said CCS chain description includes the return of CO2 carriers to consider the vaporised CO2 (VCO2) in returning carriers. According to Hyonjeong et al., the same volume of VCO2 must be loaded into the carrier's cargo tank when unloading LCO2 from the carrier to the CO2 terminal. The carrier's cargo tank is displaced by the VCO2 of the storage tanks at the terminal, while LCO2 fills the storage tanks. There are two reasons for loading VCO2 into the carrier's cargo tank. The first is to allow the pressure and temperature of the cargo tank to be controlled during the unloading process. Constant pressure and temperature facilitate the process. The second reason is to prevent the rapid decrease in temperature due to Joule-Thomson cooling.
[0008] Thus, for example, during LCO2 cargo transfer between ship and onshore intermediate storage, the displaced vapour in the onshore intermediate storage tank could be returned to the CO2 carrier ship via a vapour return connection for pressure maintenance in both sets of tanks, i.e. of the carrier ship and of the intermediate storage of the CO2 receiving terminal, respectively.
[0009] However, depending on origin and purity of the LCO2 being received at the terminal, the vapour in the onshore storage tank or tanks may contain impurities. In the event that restrictions are imposed on the vapour quality of vapour being returned to the ship that are not met by the vapour composition in the onshore storage, such impurities could pose a substantial impediment to the functioning of the CCS chain. In particular, LCO2 receiving terminals served by multiple customers, with CO2 originating from various sources, could face challenges from a technical and commercial point with undesired cross-contamination caused by impurities contained in the vapour space of the onshore storage tanks when returned to the ships.
[0010] JP H06 33873 B2 discloses a cargo handling device for receiving LNG carried by an LNG tanker into a land-based receiving tank. A branch line is provided on an LNG discharge line from the LNG tanker. The LNG branched off via the branch line is depressurised by a pressure reducing valve and vaporised in a vaporiser, to which vaporiser latent heat of vaporisation is provided from the remaining LNG discharge stream which is thereby being cooled, before entering into the receiving tank.
[0011] It would be desirable to enable pressure maintenance in a discharging tank and a receiving tank, while reducing, and preferably avoiding, the risk of contaminating a discharging tank with possible contaminants from the receiving tank. Moreover, this should preferably be achieved in an energy-efficient manner. It is an object of the present invention to provide a system and a method enabling the above.
[0012] SUMMARY OF THE INVENTION
[0013] The present invention is based on subjecting a liquefied gas transfer stream to a reduced pressure, thereby partly vaporising the transfer stream, separating the transfer stream into a liquid phase and a vapour phase, and forwarding the separated liquid phase having a reduced pressure and temperature to a receiving tank, while the separated vapour is compressed and returned to the discharging tank.
[0014] The present invention allows for transferring into the receiving tank a liquefied gas stream with a saturation pressure below that of the receiving tank. With sufficient subcooling from the liquefied gas stream being introduced into the receiving tank, this allows for reducing the pressure rise during loading (due to the colder incoming liquid "collapsing" the vapour by condensing part of it). An advantage of the inventive idea is that it suppresses the formation of vapour in the receiving tank, and may also eliminate or substantially reduce the need for refrigeration, or reliquefaction of vapour or boil-off gas from the receiving tank to stay within pressure capabilities of the receiving tank.
[0015] As opposed to the prior art, the present invention does not rely on the use of indirect heat transfer from one flow of a fluid to another flow of a fluid, such as in a heat exchanger or in a vaporiser such as disclosed in JP H06 33873 B2. Also, the invention does not rely on the use of a heat source for vaporisation. Moreover, according to the invention, a stream for vaporisation is not being branched off from the transfer stream. Instead, according to the invention, at least 20 % of the entire transfer stream from the discharging tank is passed through an expansion valve and then passed further to a flash tank thereby cooling itself and generating gas for vapour return. Accordingly, up to 80 % of the total discharge stream can be transferred without such treatment to the receiving tank.
[0016] Accordingly, in one aspect the invention relates to a system 100, 110 configured to transferring a liquefied gas stream from a discharging tank 30 to a receiving tank 45, said system comprising: a discharging tank 30 configured to discharging a stream of liquefied gas contained in the tank; a receiving tank 45 configured to receiving, and accommodating within the tank, a liquefied gas; a receiving conduit 5, 16, 22, 24 connected to the receiving tank 45 configured to receiving a transfer stream of liquefied gas from the discharging tank 30 and to leading the transfer stream of liquefied gas to the receiving tank 45; a vapour return conduit 18, 20 configured to return compressed vapour to the discharging tank 30; a vapour return compressor 85 arranged along the return conduit 18, 20 configured to receive vapour generated within the system 100, 110, and to compress the vapour and exit same in a compressed state, which system additionally comprises: an expansion valve 81 arranged along the receiving conduit 5, 16, 22, 24 configured to receive the transfer stream of liquefied gas, and to reduce the pressure of the transfer stream of liquefied gas thereby partly vaporising the transfer stream of liquefied gas; a flash tank 83 arranged along the receiving conduit 5, 16, 22, 24 on a downstream side of expansion valve 81 configured to receive the transfer stream of partly vaporised liquefied gas from the expansion valve 81 and to separate the stream into a liquid phase and a vapour phase; a booster pump 87 arranged along the receiving conduit 5, 16, 22, 24 on a downstream side of the flash tank 83 configured to receive and withdraw a stream of liquid phase from the flash tank 83 and to compress and forward the resulting stream of compressed liquid phase to the receiving tank 45; wherein the flash tank 83 is arranged upstream of the vapour return conduit 18, 20 and connected to said vapour return conduit 18, 20 configured to exit into said vapour return conduit 18, 20 a stream of the vapour phase separated in the flash tank, and wherein the vapour return conduit 18, 20 is configured to return the vapour into the headspace of the discharging tank 30.
[0017] In a preferred embodiment of the system 100, 110 the liquefied gas is liquefied CO2.
[0018] In yet a preferred embodiment the system 100, 110 is integrated into an LCO2 receiving terminal connected to a long-term LCO2 storage facility, wherein the receiving tank 45 is an LCO2 intermediate storage tank; and, the discharging tank 30 is an LCO2 tank on an LCO2 carrier ship.
[0019] The system 100, 110 may additionally comprise a refrigeration system 40, 42, 50. In one embodiment, refrigeration system 40, 42, 50 is configured to circulate and refrigerate a cooling medium which is used for providing refrigeration indirectly to the contents of the receiving tank 45, such as by passing the cooling medium through conduits, such as coils, in contact with the tank, externally or internally. In another embodiment, refrigeration system 40, 42, 50 is configured to withdraw fluid from receiving tank 45, remove heat from the withdrawn fluid in refrigeration unit 50, which will reduce the enthalpy, and return the reduced- enthalpy stream back to the receiving tank 45. Such embodiment covers both subcooling and vapour condensation as possible options. When included in the inventive system 100, it is presently being preferred that refrigeration system 40, 42, 50 serves to liquefy vapour withdrawn from the head space of the receiving tank 45 and to return liquefied vapour to the receiving tank 45. Liquid subcooling is presently being preferred.
[0020] In one embodiment 110 of the system a bypass conduit 60 is included connecting conduit 5 with conduit 24, thereby bypassing expansion valve 81, flash tank 83 and booster pump 87.
[0021] In another aspect, the invention relates to a method of transferring a liquefied gas stream from a first discharging tank 30 to a receiving tank 45, avoiding contamination from the receiving tank to the first, or to a subsequent, discharging tank, said method comprising the following steps: A - discharging from a first discharging tank 30 a stream of liquefied gas contained therein; B - forwarding a stream of the discharged liquefied gas from step A to a receiving tank 45; C - returning to the first discharging tank 30 a stream of compressed vapour; which method additionally comprises the following steps: D - reducing the pressure of the at least a partial stream of entire stream of liquefied gas discharged in step A, thereby partly vaporising the at least partial stream of liquefied gas, so as to obtain a partly vaporised stream of liquefied gas having a lower pressure and a lower temperature than the liquefied gas being discharged in step A; E - separating the partly vaporised liquefied gas from step D into a liquid phase and a vapour phase, respectively; F - compressing the liquid phase from step E; wherein, in step B, the stream of discharged liquefied gas being forwarded to the receiving tank 45 is the compressed liquid phase obtained in step F and any remaining partial stream of the entire discharged liquefied gas not having been subjected to steps D, E, and F; and, in step C, the stream of compressed vapour is obtained from the vapour resulting from step E, and wherein, in step C, the stream of compressed vapour is returned into the headspace of the discharging tank 30.
[0022] In a preferred embodiment the liquefied gas is LCO2, preferably at an LCO2 receiving terminal connected to long-term LCO2 storage reservoir. According to the inventive method no vapour or liquefied gas is being transferred from the receiving tank 45 to the first discharging tank 30, or to a second or further discharging tank 30.
[0023] In a preferred embodiment, the method additionally comprises the following steps: G - withdrawing fluid from the receiving tank 45; H - removing heat from the withdrawn fluid from step G thereby obtaining a fluid having a reduced enthalpy; and, I - returning the fluid having a reduced enthalpy from step H to the receiving tank 45.
[0024] More preferably, in step G, liquid phase from the receiving tank 45 is withdrawn, in step H, the withdrawn liquid phase from step G is subcooled, and in step I, the subcooled liquid phase from step H is returned to the receiving tank 45.
[0025] In an alternative preferred embodiment, the method additionally comprises the following steps: J - circulating and refrigerating a cooling medium in a conduit 40, 42; and K - indirectly contacting the circulating cooling medium of step J with the contents of the receiving tank 45. Such embodiments may be especially suitable where it is desirable to reduce the pressure rise in the receiving tank 45 even further.
[0026] The present invention provides a method and a system which are apt to provide vapour return for pressure support of discharging LCO2 carrier ship tanks 30 during liquid off-loading by generating vapours directly from the off-loading cargo at an LCO2 receiving terminal, while eliminating the risk for potential contamination by contaminants contained in the vapour return from a receiving storage tank 45.
[0027] The cooling effect achieved according to the invention is enhanced as compared to prior art cooling which uses indirect transfer of heat from one fluid stream to another, e.g. via a heat exchanger. The present invention does not rely on the use of a heat exchanger for vaporisation, which would undesirably reduce the achievable cooling effect due to temperature approach limitations. Accordingly, a heat exchanger is preferably not present along the transfer conduit 5, 16, 22, 24 of the inventive system 110, 110, and preferably also not along the bypass line 60 of the embodiment 110 of the inventive system, and not used in the inventive method. Also, by means of the present invention, the power requirement can be markedly reduced, such as by 33 %, as compared to the prior art systems.
[0028] For an enhanced power requirement reduction it is preferred that an as large fraction as possible of the entire transfer stream be treated according to the invention. Accordingly, it preferred that a major fraction (i.e. more than 50 %) of the entire transfer stream is subjected to the inventive treatment, more preferably essentially the entire transfer stream is subjected to the inventive treatment.
[0029] Moreover, the inventive system and method require less equipment as compared to the prior art methods.
[0030] Further embodiments and advantages of the invention will be apparent from the following detailed description and appended claims.
[0031] BRIEF DESCRIPTION OF THE ATTACHED DRAWINGS
[0032] Figure 1 shows an embodiment 100 of the inventive system intended for treatment of an entire transfer stream of a liquefied gas by subjecting the transfer stream to an expansion valve 81, flash tank 83 and booster pump 87.
[0033] Figure 2 shows an embodiment 110 of the inventive system intended for treatment of a fraction an entire transfer stream of a liquefied gas. The embodiment includes a bypass conduit 60 connecting conduit 5 with conduit 24, thereby bypassing the inventive expansion valve 81, flash tank 83 and booster pump 87, corresponding to method steps D, E, and F, respectively.
[0034] The inventive system 100, 110 in its most generic embodiment does not include the refrigeration unit 50 along with associated conduits 40 and 42. In FIG. 1 and FIG. 2, the inventive system 100 and 110, respectively, have been illustrated for LCO2 as the liquefied gas, wherein the LCO2 intermediate storage tank is the receiving tank 45. In operating the system, a first discharging tank 30 will typically, after discharge thereof, be replaced with a second discharging tank 30, wherein e.g. the first discharging tank 30 may be onboard one LCO2 carrier ship, and the second discharging tank 30 may be onboard a different LCO2 carrier ship. DETAILED DESCRIPTION OF THE INVENTION
[0035] While the invention has been developed in relation to carbon capture and storage (CCS) technology and LCO2 receiving terminals, it is believed that the technology could in principle be used with any liquefied gas, especially in discharging operations wherein the discharging tank is being exchanged for another after discharging thereof, such as e.g. when ships arrive at a LCO2 receiving terminal for unloading, and where it is desirable not to risk contaminating a discharging tank with contents, such as vapour, from a previous discharging tank.
[0036] Handling of liquefied gases below ambient temperature often requires mechanical refrigeration to maintain or lower the pressure in the storage, without venting the gas to atmosphere or another location. Particularly in the case of loading the receiving tank with LCO2 from a discharging tank without sending vapour return from the former to the latter, the required refrigeration duty to maintain receiving tank pressure within design limits can impose a significant intermittent power requirement, which is undesirable. High refrigeration duties imply high power input requirements. The present invention reduces or even eliminates the need for dedicated mechanical refrigeration for receiving tank loading without vapour return from the receiving tank.
[0037] According to the present invention, vapour from the head space of the discharging tank 30 is not transferred to the flash tank 83 or to receiving tank 45 during transfer of liquefied gas from the discharging tank 30 to the receiving tank 45.
[0038] According to the present invention, during transfer of liquefied gas from the discharging tank 30 to the receiving tank 45, the pump 87 and compressor 85 are operated simultaneously.
[0039] The invention will now be disclosed in more detail with reference to a case wherein the liquefied gas is LCO2. With reference to FIG. 1, an expansion valve 81 reduces the pressure of the incoming LCO2 stream 5 to below the saturation pressure of the incoming LCO2, causing it to flash (partly vaporise). The resulting vapour-liquid mixture downstream expansion valve 81 is colder and lower in pressure than the incoming LCO2 upstream of the expansion valve 81 (and thus has a lower saturation pressure than the LCO2 in the discharging tank 30). The colder, lower-pressure liquid is pumped by pump 87 into the receiving tank 45, thereby reducing the pressure rise in the receiving tank 45 compared to filling with the LCO2 directly from the discharging tank 30. The vapour separated in the flash tank 83 is then compressed by compressor 85 and sent to the discharging tank 30 for pressure maintenance by replacing the discharged liquid volume. As also shown in FIG. 1, if desired, an additional refrigeration system 40, 42, 50 can be provided to reduce pressure rise in the receiving tank 45 even further.
[0040] For a given transfer operation according to the invention, wherein a given mass of a liquefied gas is transferred from a discharging tank 30 at a given rate at given initial conditions in the discharging tank 30 to a receiving tank 45, the overall power requirement, including any refrigeration duty, is believed to be substantially smaller than in a corresponding prior art operation. The invention can thus greatly reduce the refrigeration duty required.
[0041] In the embodiment of the invention illustrated in FIG. 1 and FIG. 2, LCO2 is offloaded from a discharging tank 30 on a ship at pressures from e.g. 15-18 barg (denoted as medium pressure (MP), with a typical saturation temperature between -30°C and -20°C).
[0042] The vapour return compressor 85 is preferably configured to increase the pressure to be compatible with the ship cargo discharging tank 30 pressure.
[0043] Vapour is returned to ship discharging tank 30 at pressure and temperature compatible with the MP cargo at a rate that approximately equals the volumetric flow of LCO2 being transferred.
[0044] Ideally, in a case of operation wherein BOG and / or displaced vapour can be completely re-liquefied in the storage tank 45 by virtue of the cooler liquefied gas entering the receiving tank 45, a BOG-handling system 50 is not required.
[0045] A BOG-handling sub-system 50 may be included in the inventive system 100, 110 in order to handle any excessive pressure rise in the receiving tank 45 not being balanced by the colder liquefied gas being fed to the receiving tank 45.
[0046] Although not preferred, the at least partial stream of liquefied gas comprising at least 20
[0047] % of the entire transfer stream of liquefied gas could be subdivided into partial streams being treated in parallel according to the invention (not shown), which could be forwarded to one or more (not shown) receiving tanks 45.
[0048] LIST OF REFERENCE SIGNS USED
[0049] 5, 16, 22, 24 receiving conduit connected to the receiving tank
[0050] 18, 20 vapour return conduit
[0051] 30 discharging tank 40 vapour conduit from head space of receiving tank
[0052] 42 liquefied gas conduit connected to receiving tank
[0053] 45 receiving tank
[0054] 50 refrigeration unit
[0055] 81 expansion valve 83 flash tank (arranged along the receiving conduit 5, 16, 22, 24)
[0056] 85 vapour return compressor
[0057] 87 booster pump (arranged along the receiving conduit 5, 16, 22, 24)
[0058] 100 system configured to transferring a liquefied gas stream from a discharging tank to a receiving tank 110 system configured to transferring a liquefied gas stream from a discharging tank to a receiving tank also including a bypass conduit 60
Claims
CLAIMS1. A system (100, 110) configured to transferring a liquefied gas stream from a discharging tank (30) to a receiving tank (45), said system comprising:- a discharging tank (30) configured to discharging a transfer stream of liquefied gas contained in the tank;- a receiving tank (45) configured to receiving, and accommodating within the tank, a liquefied gas;- a receiving conduit (5, 16, 22, 24) connected to the receiving tank (45) configured to receiving a transfer stream of liquefied gas from the discharging tank (30) and to leading the transfer stream of liquefied gas to the receiving tank (45);- a vapour return conduit (18, 20) configured to return compressed vapour to the discharging tank (30);- a vapour return compressor (85) arranged along the return conduit (18, 20) configured to receive vapour generated within the system (100, 110), and to compress the vapour and exit same in a compressed state, which system additionally comprises:- an expansion valve (81) arranged along the receiving conduit (5, 16, 22, 24) configured to receive the transfer stream of liquefied gas, and to reduce the pressure of the transfer stream of liquefied gas thereby partly vaporising the transfer stream of liquefied gas;- a flash tank (83) arranged along the receiving conduit (5, 16, 22, 24) on a downstream side of expansion valve (81) configured to receive the transfer stream of partly vaporised liquefied gas from the expansion valve (81) and to separate the stream into a liquid phase and a vapour phase,- a booster pump (87) arranged along the receiving conduit (5, 16, 22, 24) on a downstream side of the flash tank (83) configured to receive and withdraw a stream of liquid phase from the flash tank (83) and to compress and forward the resulting stream of compressed liquid phase to the receiving tank (45),wherein the flash tank (83) is arranged upstream of the vapour return conduit (18, 20) and connected to said vapour return conduit (18, 20) configured to exit into said vapour return conduit (18, 20) a stream of the vapour phase separated in the flash tank, and wherein the vapour return conduit (18, 20) is configured to return the vapour into the headspace of the discharging tank (30).
2. The system (100, 110) of claim 1, wherein the liquefied gas is liquefied CO2 (LCO2).
3. The system (100, 110) of claim 2, wherein the system is integrated into an LCO2 receiving terminal connected to a long term LCO2 storage reservoir, wherein- the receiving tank (45) is an LCO2 intermediate storage tank; and,- the discharging tank (30) is an LCO2 tank on an LCO2 carrier ship.
4. The system (100, 110) of any one of the previous claims, additionally comprising a refrigeration system (40, 42, 50) configured to circulate and refrigerate a cooling medium used for providing refrigeration indirectly to the contents of the receiving tank (45), or configured to withdraw fluid from receiving tank (45), remove heat from the withdrawn fluid in refrigeration unit (50), and return a reduced-enthalpy fluid stream back to the receiving tank (45).
5. The system (110) of any one of the previous claims, wherein a bypass transfer conduit (60) is arranged connecting the conduit 5 with conduit 24 thereby bypassing expansion valve (81), flash tank (83) and booster pump (87).
6. The system (100, 110) of any one of claims 1-4, wherein there is not a heat exchanger arranged along the receiving conduit (5, 16, 22, 24) connected to the receiving tank (45).
7. The system (110) of claim 5, wherein there is not a heat exchanger arranged along the receiving conduit (5, 16, 22, 24) connected to the receiving tank (45) and also not along the bypass transfer conduit (60).
8. A method of transferring a liquefied gas stream from a first discharging tank (30) to a receiving tank (45), avoiding cross-contamination between the tanks, said method comprising the following steps:A - discharging from a first discharging tank (30) a stream of liquefied gas contained therein;B - forwarding a stream of the discharged liquefied gas from step A to a receiving tank (45);C - returning to the first discharging tank (30) a stream of compressed vapour; which method additionally comprises the following steps:D - reducing the pressure of at least a partial stream of liquefied gas comprising at least 20 % of the entire stream of liquefied gas discharged in step A , thereby partly vaporising the at least partial stream of liquefied gas, so as to obtain a partly vaporised stream of liquefied gas having a lower pressure and a lower temperature than the liquefied gas being discharged in step A;E - separating the partly vaporised liquefied gas from step D into a liquid phase and a vapour phase, respectively;F - compressing the liquid phase from step E; wherein, in step B, the stream of discharged liquefied gas being forwarded to the receiving tank (45) is the compressed liquid phase obtained in step F and any remaining partial stream of the entire discharged liquefied gas not having been subjected to steps D, E and F; and, in step C, stream of compressed vapour obtained from the vapour resulting from step E, and wherein, in step C, the stream of compressed vapour is returned into the headspace of the discharging tank (30).
9. The method of claim 8, wherein the liquefied gas is liquefied CO2 (LCO2), preferably at an LCO2 receiving terminal connected to long-term LCO2 storage reservoir.
10. The method of claim 8 or 9, wherein no vapour or liquefied gas is being transferred from the receiving tank (45) to the first discharging tank (30) or to the flash tank (83).
11. The method of any one of claims 8-10, additionally comprising the following steps:G - withdrawing fluid from the receiving tank (45);H - removing heat from the withdrawn fluid from step G thereby obtaining a fluid having a reduced enthalpy; and,I- returning the fluid having a reduced enthalpy from step H to the receiving tank (45).
12. The method of any one of claims 8-10, additionally comprising the following steps:J - circulating and refrigerating a cooling medium in a conduit (40, 42); and,K - indirectly contacting the circulating cooling medium of step J with the contents of the receiving tank (45).
13. The method of any one of claims 9-12, wherein the steps are repeated with a second discharging tank (30).
14. The method of any one of claims 8-13, wherein the at least partial stream comprises a major fraction of the entire transfer stream, and preferably comprises the entire transfer stream.