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O
ver the past two decades, the growth of the LNG trade has provided many countries with clean,
affordable energy. With the world undergoing a clean energy revolution, the global use of LNG as an
energy source is sure to grow. A major selling point of LNG is that it can be transported by LNG tankers.
This allows for the transportation to be independent of pipelines, which are economic and political hot buttons.
With more LNG terminals being built to import and export the product, the need to properly maintain LNG
is greater than ever. One of the most challenging aspects in properly conserving LNG is how to keep it cold.
Traditional insulation methods cannot be used, so special cryogenic insulating techniques have been
developed.
Cryogenic insulation is crucial, as faults can compromise the quality of the product itself, which would, in
turn, increase production cost. Therefore, material selection is important.
Liquefaction cost
In natural gas, it takes 1000 ft
3
, or almost 7500 gal., to yield 1 million Btu. This number decreases when it
is applied to LNG. As methane compresses to 1/610
th
of its initial volume when it becomes a liquid, these
7500 gal. become just 12.3 gal. of LNG per million Btu.
Table 1 shows the total liquefaction fixed cost per million Btu produced in different regions of the world.
This liquefaction cost is broken down into three main components: operation and maintenance, capital cost,
and fuel use cost, including the 9% of LNG that is burned off during liquefaction. Based on these numbers, in
the US, the liquefaction cost to produce 12.3 gal. of LNG is US$2.14, which is approximately US$0.17/gal.
and is the lowest cost in the world. The highest liquefaction cost is in the Oceanic region at over
US$0.34/gal. of LNG.
Nick Pellon,
Thermaxx Jackets,
USA,
explains how the
application of cryogenic
insulation jackets on valves
and flanges can help to
reduce costs in LNG plants.
