Construction/Installation 



The construction of an onshore liquefaction or regasification plant 

 requires the clearing of land in the immediate vicinity of the plant and 

 making the topography as level as possible. This will require the use 

 of heavy earth-moving equipment. With the selection of a coastal site, 

 there is an unusually high probability that low-lying wetlands will be 

 excavated and filled with sand and/or gravel to make a firm working 

 surface. Storage tanks will have to be constructed with protective berm 

 enclosures to contain fluids in case of leaks or ruptures. 



A marine terminal will be constructed for unloading the LNG ship. 

 If it is to be a close-in dock, there may be a requirement for a navigation 

 channel to approximately 40 feet deep and a turning basin about four 

 times the ship's length or 3,600 feet. If a channel and turning 

 basin arenot readily available, the sponsor is likely to build a long 

 pipeline or trestle out to a depth adequate for LNG ships. Construction 

 of an underwater pipeline would involve underwater trenching and filling. 

 In some cases, ship-to-shore pipelines will be on a trestle, (Oxnard, 

 California) or enclosed in a tunnel (Cove Point, Maryland), which could 

 also serve to transport personnel between the plant and the marine 

 terminal [53]. 



Operation 



In receiving natural gas from an offshore gas field, a liquefaction 

 plant first removes impurities and then cools the gas under pressure to 

 approximately -250° F. This causes a reduction in volume greater than 

 600 times and converts the gas into a liquid. From this point until the 

 time of regasification the gas must be maintained under constant low 

 temperatures and high pressures. The liquefied gas is held in storage 

 tanks until it can be loaded onto an LNG tanker for shipment. The basic 

 constituents of a liquefaction plant are compressors and cooling apparatus, 

 storage tanks, a marine terminal, underwater pipelines from the gas 

 field, blowers, pumps, metering systems, administrative offices and 

 maintenance buildings. 



The regasification facility is essentially the reverse of a 

 liquefaction plant having many of the same components, such as the 

 marine terminal pumps and underwater pipelines. The difference is the 

 presence of vaporizers which heat and reconvert the LNG to a gaseous 

 state. A typical regasification procedure is described by the following 

 and illustrated in Figures 44 and 45. 



1. LNG tanker docks at the marine terminal. 



2. Articulated unloading arms attach to ship. 



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