Liquefied natural gas storage

Figure 3.1.2 Purging a liquefied-natural-gas storage tank.

Aagaard, V., Ledegaard, B. H., Liquefied Natural Gas Storage, Barcelona, CN Post NR 87, Christiani Wielsen, Kobenhaven, Denmark, Nov., 1969. 

Fig. 11. Cross-section through a typical prestressed-concrete liquefied natural gas storage tank. °...

Krstulovic-Opara, N. (2007) Liquefied natural gas storage material behavior of concrete at cryogenic temperatures, A Cl Materials Journal. May-June pp. 297-306. 

Liquefied natural gas (LNG) also plays a large role in both the transportation and storage of natural gas. At a pressure of 101.3 kPa (1 atm), methane can be Hquefted by reducing the temperature to about — 161°C. When in the Hquid form, methane occupies approximately 1/600 of the space occupied by gaseous methane at normal temperature and pressure. In spite of the very low temperature of the Hquid, LNG offers advantages for both shipping and storing natural gas. 

Liquefied Natural Gas (LNG) plants can be categorized as peakshaving or baseload. Peakshaving LNG plants are built at the consumer end of natural gas pipelines to accumulate LNG in storage tanks for later vaporization and sendout into the local grid during periods of peak demand. Baseload LNG plants provide a steady base supply of natural gas to utiHty companies, generally by transportation of LNG by ship from one country to another. 

NFPA Standard 59A, Standard for the Production, Storage, and Handhng of Liquefied Natural Gas (LNG)... 

Fuel modification in terms of volatility, hydrocarbon types, or additive content. Some of the fuels currently being used are liquefied petroleum gas (LPG), liquefied natural gas (LNG), compressed natural gas (CNG), fuels with alcohol additives, and unleaded gasoline. The supply of some of these fuels is very limited. Other fuel problems involving storage, distribution, and power requirements have to be considered. 

N. J. Cupurus, Developments in Cryogenic Storage Tanks, Paper presented at 6th International Conference on Liquefied Natural Gas, Kyoto, Japan, 1980. 

To remain a liquid at a reasonably low pressure, liquefied natural gas (LNG) must be maintained at below at least -117°F. Insulated storage tanks alone cannot maintain these very cold temperatures. LNG is stored at its boiling point to take advantage of autorefrigeration. Just as the temperature of water does not rise above its boiling point (212°F) with increased heat (it is cooled by evaporation), LNG is kept near its boiling point if kept at a constant pres-... 

In mining and, more recently, the construction of underground storage tanks for liquefied natural gas, it is often necessary to sink a shaft through water-logged ground. The requirement is to form a temporary cofferdam to permit excavation and the building of a permanent liner. 

Liquefied natural gas is loaded to truck or rail cars and sent to market as a liquid. LNG fuel plants are usually running year round, while the peak shaving units run only in off-peak periods - typically in the spring to autumn season - to the extent that storage is complete for the high demand winter season. This distinction, however, results in large variations in the capital cost, and should be carefully considered in the context of transit countries. 

Liquefied natural gas plants for peak shaving and vehicle fuel production are generally similar in the pre-treatment and liquefaction areas. However, these plants differ substantially in terms of storage and send-out facilities as shown in Table 2. Indeed, these discrete differences make a huge impact on the capital cost ... 

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