Description
Liquefied natural gas or LNG is natural gas (predominantly
methane, CH4) that has been converted to liquid form for ease of
storage or transport.
Liquefied natural gas takes up about 1/**0th the volume of
natural gas in the gaseous state. It is odorless, colorless,
non-toxic and non-corrosive. Hazards include flammability, freezing
and asphyxia.
A typical LNG process. The gas is first extracted and
transported to a processing plant where it is purified by removing
any condensates such as water, oil, mud, as well as other gases
such as CO2 and H2S. An LNG process train will also typically be
designed to remove trace amounts of mercury from the gas stream to
prevent mercury amalgamizing with aluminium in the cryogenic heat
exchangers. The gas is then cooled down in stages until it is
liquefied. LNG is finally stored in storage tanks and can be loaded
and shipped.
LNG achieves a higher reduction in volume than compressed
natural gas (CNG) so that the energy density of LNG is 2.4 times
heavier than that of CNG or *0% of that of diesel fuel.[1] This
makes LNG cost efficient to transport over long distances where
pipelines do not exist. Specially designed cryogenic sea vessels
(LNG carriers) or cryogenic road tankers are used for its
transport.
LNG is principally used for transporting natural gas to
markets, where it is regasified and distributed as pipeline natural
gas. It can be used in natural gas vehicles, although it is more
common to design vehicles to use compressed natural gas. Its
relatively high cost of production and the need to store it in
expensive cryogenic tanks have hindered widespread commercial
use.
Cooling natural gas to about ***0°F at normal pressure results
in the condensation of the gas into liquid form, known as Liquefied
Natural Gas (LNG). LNG can be very useful, particularly for the
transportation of natural gas, since LNG takes up about one six
hundredth the volume of gaseous natural gas. While LNG is
reasonably costly to produce, advances in technology are reducing
the costs associated with the liquification and regasification of
LNG. Because it is easy to transport, LNG can serve to make
economical those stranded natural gas deposits for which the
construction of pipelines is uneconomical.