WO2012126279A1

WO2012126279A1 - Receiving system and processing method for liquefied natural gas

Info

Publication number: WO2012126279A1
Application number: PCT/CN2012/000351
Authority: WO
Inventors: 吴树凯
Original assignee: 益资海洋工程技术(北京)有限公司
Priority date: 2011-03-21
Filing date: 2012-03-21
Publication date: 2012-09-27
Also published as: CN102242864A

Abstract

A receiving system for liquefied natural gas (LNG) comprises: an LNG carrier, carrying LNG to travel to and fro between the receiving system and an LNG source; an LNG carrier anchoring dock, provided with a pipeline used for unloading the LNG from the LNG carrier through an LNG unloading system; the LNG unloading system, used for unloading, through a low-temperature pipeline arranged on a terminal marine facility and an LNG transmission system, the LNG from the carrier to an LNG storage system; the LNG storage system, the LNG being transmitted from the LNG storage system through the LNG transmission system to a re-gasification system, an LNG bulk transshipping system and an LNG container transshipping system; the LNG re-gasification system, for outputting the gasified natural gas; the LNG transmission system, arranged between the LNG storage system and the LNG receiving terminal marine facility as well as between the re-gasification system and the LNG storage system, and used for transmitting the liquefied gas or the re-gasified gas therebetween.

Description

Description: A liquefied natural gas receiving system and processing method

The present invention relates to a liquefied natural gas (LNG) storage and transportation technology, and more particularly, to a liquefied natural gas receiving system and a processing method. Background technique

The use of natural gas outside of the gas source is usually carried out in three ways. The first is to send natural gas from the gas source to the user using the natural gas pipeline. The second is to liquefy natural gas in the gas source to form liquefied natural gas (LNG), which is transported by water or land to the place of use, and then re-gasified to the user after use. The third is to compress natural gas to form compressed natural gas (CNG) by water or land to the user.

Long-distance water transport is currently transported in the form of liquefied natural gas. Combined with the actual situation in China, the eastern coastal areas are economically developed and have a large amount of gas, but they lack gas sources. Although they are imported through the pipeline from the west, the gap is still large and needs to be imported from abroad. Most of these natural gas are transported by ship to the gas receiving terminal in the form of liquefied natural gas, which is sent to the user after unloading, storage, and regasification. For fixed terminals on land, usually LNG carriers are docked at the dockside, connected to the receiving terminal, and the LNG is unloaded to the LNG storage device through the unloading system, and then the LNG is sent to the regasification device through the transmission system. After regasification, the natural gas is sent to the user.

At present, the main function of the common LNG receiving terminal is to store and re-gasify, and the liquefied weather of the ship is unloaded to the receiving terminal for storage, and then re-gasified and sent to the local pipe network, and sent to the user through the pipe network; or Directly sent to large gas users such as power plants, smelters, etc. The receiving terminal has a single function, a single user, and a small user coverage, which cannot meet the various needs of people for using natural gas. As the types and forms of natural gas users increase, functional requirements for LNG, CNG transport, and loading of LNG fuel ships are proposed for LNG receiving terminals.

In addition, during the process of loading or unloading or storing, the liquefied natural gas will generate flash vapor due to the introduction of heat and physical displacement. The flash vapor is in a low temperature state, and the amount of flash gas per day is usually 0.1%-0.3%. Over time, flash vapors continue to increase in the tank, affecting safety and requiring treatment. For the LNG receiving terminal, the common treatment method is: A part of the flash steam is returned to the LNG cabin during unloading to balance the pressure inside the gun, part of which is recondensed and returned to the LNG storage tank, and then the excess is burned or Discharge into the air, not only waste but also disadvantageous Environmental protection. Summary of the invention

In order to avoid various defects of the above natural gas receiving terminal, the present invention proposes a receiving system for liquefied natural gas and a processing method thereof.

According to an aspect of the invention, a liquefied natural gas receiving system is provided, comprising: an LNG carrier, an LNG carrier dock, an LNG unloading system, an LNG transmission system, an LNG storage system, a LNG regasification system, a flash steam treatment system , LNG transport systems (including maritime transport and / or on-road transport; bulk transport and / or container transport), CNG transport system (including water and / or onshore container transport), LNG fuel ship loading system. The LNG carrier transports LNG between the receiving system and the LNG source; the LNG carrier dock has pipes for unloading LNG from the LNG carrier through the LNG unloading system; the LNG unloading system is used to Low-temperature pipelines and LNG transmission systems on terminal offshore facilities, unloading LNG from transport vessels to LNG storage systems; LNG storage systems, LNG transport from storage systems through LNG transport systems to regasification systems, or to LNG bulk transporters Ships and LNG container transfer vessels are transported by sea, or to LNG carriers for land transport; LNG regasification systems, LNG gasification of natural gas for external transport; LNG transport systems, arranged for LNG storage systems and LNG receiving terminal seas Between the facilities, and between the regasification system and the LNG storage system, the liquefied gas or regasified gas is transferred therebetween.

According to another aspect of the present invention, a liquefied natural gas receiving processing method is provided, including: Step 1), an LNG carrier is docked at an LNG carrier dock, and an LNG unloading system is used to unload LNG from an LNG carrier, and the LNG is unloaded. The system is used to unload LNG from the transport vessel to the LNG storage system via a cryogenic pipeline and LNG transmission system located at the terminal offshore facility; Step 2), LNG is transferred from the LNG storage system through the LNG transmission system to the regasification system , or LNG dare to load the transfer system, or LNG container transfer system; Step 3), LNG regasification system will gasify the natural gas outside; Step 4), LNG storage system LNG loading system will load LNG into LNG transportation The ship, the LNG container transfer ship accepts the LNG container transported by the LNG loading system, the LNG bulk transfer ship accepts the bulk LNG transported by the LNG loading system, and the LNG ground transport unit transports the bulk or container-type LNG on land.

According to a third aspect of the present invention, there is provided a method of treating flash vapor generated during a liquefied natural gas unloading storage process, comprising: returning to a flash vapor generated during discharge or storage of LNG, a portion of which is returned to the discharge The LNG ship grabs the balance to grab the internal pressure, and the other part heats or pressurizes the flash steam. The heated natural gas is sent directly to the natural gas pipeline network or boosted and transported as CNG.

The system of the present invention is applicable to LNG receiving terminals in coastal areas, along rivers and the like. With the continuous development of China's economy With the adjustment of the energy structure, 51% of natural gas consumption by 2020 will come from LNG imports. Therefore, the large-scale introduction of LNG clean energy is an inevitable trend, and the construction of LNG receiving terminals in coastal areas will enter a new stage of development. The hub terminal based on this patent will certainly exert its good economic and social benefits in the construction of China's LNG hub terminal. DRAWINGS

Fig. 1 shows a schematic structural view of a liquefied natural gas receiving system according to the present invention. detailed description

A receiving system and a processing method for a liquefied natural gas provided by the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

In general, the present invention provides a multifunctional liquefied natural gas receiving system that increases the transport function of LNG, the service function of CNG, and the delivery of CNG on the basis of receiving terminal storage and regasification functions. Features. Among them, the transport function of LNG can be either water transport or land transport. LNG water transport can be transported in bulk or in container; LNG ground transport is transported in the form of containers. The delivery of CNG can be either water or land. CNG's water and land transportation are shipped in the form of containers.

As shown in FIG. 1, the multifunctional LNG receiving system of the present application includes: an LNG carrier, an LNG carrier dock, an LNG unloading system, an LNG storage system, an LNG regasification system, an LNG transmission system, and onshore facilities, and further Including LNG bulk transfer ship, shipping LNG planting system, LNG bulk terminal, LNG container transfer ship, LNG container terminal, shipping CNG loading system, CNG container transfer ship, CNG container transfer terminal, LNG ground transportation system and installation, CNG ground transportation Systems and devices. In this system, in addition to common storage and gasification, LNG can be transported on the one hand (ie, bulk transport and container transport), while CNG (container transport) can be transported on the other hand. LNG and CNG can be transported by water or by land. CNG can be derived from regasified natural gas and, on the other hand, from treated flash gas (BOG).

It can be understood that the system constructed by the above structure is for illustration and illustration only, and does not mean that the system must be completely constructed as shown in the figure. When implementing some of the functions mentioned in the system, it is not necessary to carry out all the components. Construct. For example, the functions of the system include receiving terminal storage, re-gasification, LNG transfer function, CNG service function and CNG delivery function. In specific implementation, it may not be processed as CNG, that is, some CNG is not needed. Additional equipment; or for some small sites, there may be problems with non-transportation or partial transport, and docking and loading systems for transport may not be constructed or partially constructed. With further reference to Figure 1, wherein, as shown in Figure 1, an LNG carrier refers to a carrier vessel carrying LNG between the receiving system and the LNG source, typically docked at a dock that is part of the terminal offshore facility.

The LNG carrier docks at the terminal and is part of the terminal offshore facility for the docking of the transport vessel and has piping for unloading LNG through the LNG unloading system.

LNG unloading system for unloading LNG. The LNG unloading system is attached to the docking terminal of the terminal offshore facility. The LNG is unloaded from the transport vessel to the LNG via the cryogenic pipeline and LNG transmission system located at the terminal offshore facility. On the storage system.

LNG storage system, LNG is transferred from the LNG storage system through the LNG transmission system to the regasification system. The storage system and the regasification system can be separate or integrated. The LNG storage system is similar to the regasification system and can be machined and then transported to the site for installation, and can be transported away as needed. LNG storage units can be constructed and installed onshore or as part of a marine LNG receiving terminal offshore facility. During the process of unloading or storage, LNG generates flash vapor (BOG) due to heat transfer and physical displacement. The flash vapor is at a low temperature, and the amount of flash gas generated is usually 0.1%-0.3%. Over time, flash vapors continue to increase in the tank and need to be disposed of. In the present invention, the generated BOG portion is returned to the cabin of the LNG carrier to balance the pressure in the cabin, and the other portion is output to the BOG heating and pressurizing device through the pipeline in the LNG storage system.

The LNG regasification system, in the form of a single tank or the like, may be self-propelled or non-self-propelled, or located on land. The regasification system has relatively fixed performance during production and operation, and the relatively fixed implementation forms mainly include pile-leg support type, pressure-carrying semi-submersible and enclosure positioning type.

The LNG transmission system is disposed between the LNG storage system and the LNG receiving terminal offshore facility, and between the regasification system and the LNG storage system for conveying the liquefied gas or the regasified gas therebetween.

Onshore facilities are systems and facilities used to support LNG receiving, regasification, and natural gas outflows or to shore waters.

The BOG heating and pressing device is located between the LNG storage system and the CNG container loading platform, and heats the BOG output from the LNG storage system to raise it to a normal temperature state, or between -15 degrees Celsius and normal temperature, and to increase the container. The amount of planted, the BOG is pressurized, and the pressurization is treated as needed, and it is possible to increase the pressure by several hundred times to reduce the volume.

The CNG container loading platform, which can be a water platform or an on-road terminal, is used to carry out the consolidation of compressed natural gas for shipment.

Shipping CNG planting system, located between CNG container loading platform and CNG container transfer vessel, for CNG The CNG container on the container loading platform is added to the CNG container transfer vessel.

CNG container transfer vessel for transporting CNG containers through waterways.

CNG ground transportation systems and installations for the loading of compressed natural gas to the ground transportation system via CNG and transport by land.

It can be transported in the form of CNG to meet the needs of some users (such as natural gas-fueled cars).

As shown in the rear end of the LNG regasification system of Figure 1, a part of the LNG output after the LNG regasification system is also pressurized and output to the CNG container loading platform for transmission by CNG. The other part is exported to the user directly in the form of gasified natural gas.

As shown in the lower part of Figure 1, the LNG storage system acts as a medium transfer platform, which allows LNGs transported by large giant ships to be directly transported at the terminal to reduce the pressure on the LNG to accept the terminal storage system, thus saving space and improving efficiency. Among them, the output of the LNG storage system is output to three locations at the lower end, first, to the LNG bulk terminal; the second is transmitted to the LNG container terminal; and third, directly to the LNG fuel ship, which uses LNG as the direct fuel. Power running.

The LNG bulk terminal is used to distribute the LNG transported by the LNG storage system to a small hull.

LNG container terminal, used for containerized processing of LNG transported by LNG storage system, facilitating long-distance and centralized transportation.

Shipping LNG loading system for loading bulk or container-type LNG from LNG bulk terminals or LNG container terminals to LNG carriers.

LNG container transfer vessel for receiving LNG containers transported by the LNG loading system.

LNG bulk transfer vessel for receiving bulk LNG from shipping LNG loading systems.

LNG ground transportation systems and installations for the transport of bulk or container-type LNG on land by on-road terminals. In addition, the regasification system and the LNG storage system can be located at sea or on land, and can be integrated or separated. When located on land, it can be directly a system. When located at sea, a corresponding platform should be established, that is, on the regasification platform. A regasification system is arranged, an LNG storage system is arranged on the LNG storage platform, and a platform lifting system is arranged in the regasification platform and/or the LNG storage platform. The Regasification System includes a gasifier and its subsidiary structure, and is disposed on a Regasification Vessel for regasifying LNG and outputting the gasified natural gas. The Platform Lifting System (VEAS) is used to change the vertical position of the regasification platform/or LNG storage platform relative to the bottom or surface of the water. The platform lifting adjustment system includes but is not limited to: (1) In order to adjust the leg support type of the regasification platform/LNG storage platform relative to the vertical position of the bottom or leg, including hydraulic jacking, gear climbing, pulley pulling Stretching or a combination of these; (2) prefabricated offshore infrastructure (with or without lifting), Support the regasification platform/LNG storage platform by adjusting the facility, and/or adjusting the draught or lifting and regasification platform/LNG storage system through the ballast water system (including direct constant weight); (3) Through the enclosure structure (including dry dock or similar facilities) to maintain relative static position in the vertical position of the gasification platform 2. The regasification platform has relatively fixed performance during production and operation, and the relatively fixed implementation forms mainly include pile leg support type, ballast semi-submersible type, and enclosure positioning type. Similarly, this fixing method can also be applied to the LNG storage platform. That is, when the regasification platform and the LNG storage platform are integrated, the receiving platform as an integral thereof can have both fixability and mobility.

For the re-gasification platform with the self-lifting fixed support of the pile legs, when the re-gasification platform is in a floating state, the pile legs are lifted by the lifting device installed on the hull platform, and the entire platform floats on the water surface. When the regasification platform is in a fixed support state, the pile legs are supported by the lifting device mounted on the hull platform, and the platform is lifted off the water surface, and is not affected by the water level change. The lifting device can be lifted off the surface by hydraulic lifting, gear climbing or pulley rope stretching. For the semi-submersible fixed regasification platform, a fixed abutment, pile or lifting device is built on the bottom of the water. After the regasification device platform is adjusted to the specified position on the water surface, it is sunk by ballast or The lifting device is raised to secure the regasification platform to the underwater abutment, fixed pile or lifting device. For the submersible fixed regasification platform, a closable enclosure structure is constructed on the water surface, and the regasification device platform is driven into the enclosure structure to extract some or all of the water in the enclosure. The regasification unit platform is fixed. The enclosure includes a retaining base, fixed side walls in three directions, and side walls with a door in one direction.

The regasification platform is movable, and when the regasification platform is not fixed, the regasification platform can be adjusted into a floating body to move from the ground to the ground. For example, the regasification platform can be built again, and the water can be transported to the B. When the peak is needed, the regasification platform can be towed to other places for peak shaving; when it is overhauled, it can be repaired. The platform is towed to the dock for maintenance, and another platform is replaced by the original platform. What is more worth mentioning is that the mobile regasification platform maintains a static position relative to the ground without the use of single-point mooring and anchor mooring. It can be processed and built elsewhere, shipped to the site for installation, and remains stationary during production operations. Similarly, the LNG storage platform is also mobile; further, when the regasification platform and the LNG storage platform are integrated, the integrated receiving platform as an integral thereof can have the above specific features. The regasification platform and the LNG storage platform can be combined. The regasification unit and the LNG storage unit can be installed on different hull platforms or on the same platform to form an integrated receiving platform. Multiple regasification platforms and LNG storage platforms can be configured depending on the amount of gas used in the terminal. When the regasification unit and the LNG storage unit are installed on different hull platforms, the distance between the two can be adjusted to improve the fire safety performance. Also, when the two are integrated, the distance between the two should be noted. Guaranteed safety.

Further, the regasification platform can be adjusted in the vertical direction. The lifting function can be achieved by designing a lifting device on the regasification platform, or a offshore installation, or a combination of the two. The former is kept flat by upgrading the regasification platform The station is stationary, while the latter is fixed at the offshore facility by lowering the position of the platform. Once positioned, the horizontal and vertical positions of the regasification platform are typically stationary relative to the ground, but in practice it can be adjusted to specific needs.

In another embodiment, a method of treating flash vapor produced by liquefied natural gas during unloading and storage is illustrated. In the process of unloading or storage of liquefied natural gas, the flash vapor at a low temperature is generated due to the introduction of heat and physical displacement, and the amount of flash gas per day is usually 0.1%-0.3%. As time passes, flash vapors continue to increase in the tank and need to be disposed of. For LNG receiving terminals, the common treatment method is: A part of the flash steam is returned to the LNG cabin during unloading to balance the pressure in the tank, and part of it is condensed and returned to the LNG tank, and then the excess is burned or Discharge into the air. In the method of the present invention, the flash vapor returned to the LNG storage tank after condensation is not condensed and sent back to the storage tank, but is heated by the flash steam. Specifically, it is heated to a normal temperature by a heating device. In addition, according to transportation requirements, based on the inverse ratio of pressure and transport capacity, it is pressurized to increase transport capacity. The heated natural gas is sent directly to the natural gas pipeline network or boosted and then transferred out as CNG. This treatment simplifies the processing of flash steam and reduces the processing cost; and the equipment that is recondensed by flash vapor is a low temperature equipment, the heating equipment of flash steam is a normal temperature equipment, and the low temperature equipment is much more expensive than the normal temperature equipment, thereby reducing the equipment cost. .

It can be seen that the terminal system of the present invention has the function of providing external gas transmission, and also has the function of providing the transit function of the liquefied natural gas and the service function of providing the compressed natural gas, so that the range of users covered by the terminal will be greatly improved, and the service form of the terminal is also improved. With diversity.

Finally, it should be noted that the above embodiments are only used to describe the technical solutions of the present invention and are not intended to limit the technical methods. The present invention may be extended to other modifications, changes, applications, and embodiments, and thus all such Modifications, variations, applications, and embodiments are within the spirit and scope of the invention.

Claims

Claim

1. A liquefied natural gas receiving system comprising: an LNG carrier, an LNG carrier dock, an LNG unloading system, an LNG storage system, an LNG regasification system and an LNG transmission system, wherein

The LNG carrier is planted with LNG between the receiving system and the LNG source;

The LNG carrier docks at the dock and has pipes for unloading LNG from the LNG carrier through the LNG unloading system;

An LNG unloading system for unloading LNG from a transport vessel to a LNG storage system via a cryogenic pipeline and an LNG transport system located at the terminal offshore facility;

LNG storage system for transferring LNG to the regasification system via the LNG transmission system, or to the LNG bulk transfer system and the LNG container transfer ship for transshipment by sea or by LNG carrier for land transport;

LNG regasification system for gasifying LNG and externalizing gasified natural gas;

An LNG transmission system disposed between the LNG storage system and the LNG receiving terminal offshore facility, and between the regasification system and the LNG storage system for conveying liquefied gas or regasified gas therebetween;

The natural gas receiving system further includes a flash steam treatment system, an LNG transport system and a CNG transport system; wherein, the flash steam treatment system is used to process flash steam generated during storage and unloading, and the LNG transport system is used for transporting the liquefied natural gas, The CNG Outbound System is used to transport pressurized natural gas.

2. The system of claim 1 wherein the LNG storage system liquefied natural gas is transferred to an LNG fuel ship, an LNG bulk terminal and/or an LNG container terminal, and the LNG bulk terminal is used to carry the LNG transported by the LNG storage system. Sub-assembly, transfer to the transshipment vessel; LNG container terminal for containerized processing of LNG transported by the LNG storage system.

3. The system of claim 2, wherein the LNG transport system comprises a shipping LNG loading system, an LNG container transfer vessel, an LNG bulk transfer vessel, and an LNG ground transport device, and the shipping LNG loading system is used to convert the LNG The LNG of the bulk terminal or LNG container terminal is loaded to the LNG carrier, the LNG container transfer vessel is used to receive the LNG container transported by the LNG loading and unloading system, and the LNG bulk transfer ship is used to receive the bulk LNG and LNG ground transported by the LNG loading system. The unit is used for onshore transportation of bulk or container-type LNG.

4. The system according to claim 1, 2 or 3, characterized in that the flash steam treatment system comprises a BOG heating and pressurizing device, which is located between the LNG storage system and the CNG container loading platform, and outputs the BOG of the LNG storage system. Heating and/or pressure treatment is carried out.

5. The system of claim 4 wherein the CNG outbound system comprises a shipping CNG loading system, CNG container transfer ship, CNG container transfer terminal and CNG ground transportation device; CNG container loading platform for containerized processing of compressed natural gas; shipping CNG processing system, located between CNG container loading platform and CNG container transfer ship, It is used to transplant CNG containers on CNG container loading platforms to CNG container transfer vessels; CNG container transfer vessels are used to transport CNG containers through waterways; CNG ground transportation devices are used to load compressed natural gas through CNG loading systems to ground transportation systems. Transported by land and by land.

6. The system of claim 1 wherein the LNG storage system and the LNG regasification system are separate or integral and both are movable.

7. The system according to claim 1, wherein the LNG storage system returns the BOG portion generated during the unloading or storage to the cabin of the LNG carrier to balance the pressure in the cabin, and a portion in the LNG storage system. The pipe is output to the BOG heating and pressurizing device.

8. The system according to claim 1, wherein the LNG storage system and the LNG regasification system are supported by a leg support for self-lifting, by ballast semi-submersible fixing, or by a sunken subsidence. .

9. The system according to claim 8, wherein the LNG storage system and the LNG regasification system support the pile legs on the LNG storage system and the LNG regasification system on the bottom by a platform lifting system. Lifting the LNG regasification system and/or the LNG storage system out of the water surface; the LNG storage system and the LNG regasification system pass the legs of the LNG storage system and the LNG regasification system through the platform lifting system Lift off the bottom of the water and lower the LNG regasification system and / or LNG storage system to the surface.

10. A system according to claim 8 wherein the LNG storage system and LNG are regasified by ballasting LNG regasification system and/or LNG storage system, or ascending and descending underwater facilities. The system is placed on a platform, fixed pile or underwater facility built to the bottom of the water, and the unloading of the compaction or the submerged facility allows the LNG regasification system and/or the LNG storage system to float.

11. The system according to claim 8, wherein the LNG storage system and the LNG regasification system are disposed in a closable enclosure structure, and the water in the enclosure is extracted to regasify the LNG system. And/or the LNG storage system is fixed to the enclosure base and floats the regasification system and/or the LNG storage system by adding water to the enclosure.

12. A method for receiving and processing liquefied natural gas, comprising:

Step 10), the LNG carrier is docked at the dock of the LNG carrier, and the LNG unloading system is used to unload the LNG from the LNG carrier. The LNG unloading system is used to pass the cryogenic pipeline and the LNG transmission system located at the terminal offshore facility. Unloading LNG from the transport vessel onto the LNG storage system;

Step 20), the LNG is transferred from the LNG storage system through the LNG transmission system to the regasification system, the LNG bulk transfer system, and the LNG container transplanting system; Step 30), the LNG regasification system, gasifying and exporting the liquefied natural gas;

Step 40), the LNG loading system of the LNG storage system loads the UG into the LNG carrier, the LNG container transfer vessel accepts the LNG container delivered by the shipping LNG loading system, and the LNG bulk transfer vessel accepts the bulk transported by the shipping LNG loading system LNG, LNG ground transport equipment transports bulk or container-type LNG on land.

13. The method according to claim 12, further comprising heating and/or adding the BOG outputted by the LNG storage system through a BOG heating and pressing device located between the LNG storage system and the CNG container loading platform. Pressure treatment, transmission to the shipping CNG processing system.

14. The method of claim 13 further comprising: containerizing the compressed natural gas through a CNG container loading platform; passing the CNG loading system between the CNG container loading platform and the CNG container transfer vessel The CNG container on the CNG container loading platform is transplanted to the CNG container transfer vessel; the CNG container is transported through the waterway through the CNG container transfer vessel; the compressed natural gas is loaded onto the ground transportation system by CNG through the CNG ground transportation device and transported by land transportation.

15. A method of treating flash vapor generated during liquefied natural gas unloading and storage, comprising:

For the flash vapor generated during the discharge or storage of LNG, part of it is returned to the LNG tank at the time of discharge to balance the pressure inside the gun, and another part of the flash steam is heated, pressurized or not.

16. The method of claim 15 further comprising: feeding the heated flash vapor directly to the natural gas pipeline network or boosting and transporting it in the form of CNG.