The two phases in an LNG system are liquefaction for transport and 

 regasification for the market. Liquefaction plants are located as near 

 as possible to a gas field. They receive gas piped from the field, 

 remove impurities, and successively cool and compress the gas until it 

 is below the boiling temperature of minus 260°F. This causes a more 

 than 600-fold reduction in volume and converts the gas into a liquid. 

 From this point until the time of regasification, the liquefied natural 

 gas must be maintained under constant low temperatures and high pressures. 

 From the liquefaction plant, the LNG is loaded into a specialized tanker 

 for transport to the regasification site. 



An LNG tanker consists of a series of heavily insulated tanks that 

 are designed specifically to carry LNG. The tanker may be 1,050 feet long 

 with a draft of 38 feet, and a capacity of up to 165,000 cubic meters of 

 LNG, the equivalent of 3.2 billion cubic feet (BCF) of natural gas [9]. 



A regasification plant essentially reverses the processes that take 

 place at a liquefaction plant. The regasification plant receives LNG 

 from a tanker, heats the LNG in a vaporizer to return it to a gaseous 

 state, and then sends it to the market area in a natural gas pipeline. 

 The two sources of heat available for regasification of LNG are simple 

 heat exchange with seawater, or a gas or oil-fired system either in 

 direct contact with the LNG or through the use of an intermediate fluid 

 sucii as water or propane [9]. Liquefaction and regasification plants 

 hc^ve similar components, including storage tanks, marine terminals, 

 processing areas, pipelines and administrative offices (Figure 7). One 

 proposed LNG regasification plant, at Oxnard, California, will initially 

 be able to produce gas at 522 MCFD, with a maximum potential output of 

 4 BCFD. An average of one LNG tanker every five days is expected to serve 

 the plant at the initial processing rate. 



An important safety consideration that applies to the entire LNG 

 system is that LNG spills create serious major hazards from fire and 

 explosion. 



Although small LNG tankers have been unloading at Boston Harbor about 

 once a month since 1971, no major LNG system is in operation to supply the 

 United States market. There is only one liquefaction plant in the United 

 States (Kenai Peninsula in Alaska), and there are none under construction, 

 although an LNG system was considered as one means of bringing Alaskan 

 North Slope gas to the "lower 48." A pipeline through Canada to the 

 mid-west now appears to be the favored plan. Regasification plants have 

 already been built or are nearing completion at Cove Point, Maryland 

 (Chesapeake Bay), Elba Island, Georgia (Savannah River), and Lake Charles, 

 toutsiarra. Arrotfrer-regaslttcatlon pTant is"^T)roposed for Oxnard, 

 Ca4t3fornia. 



78 



