Liquified Natural Gas – is fast becoming an essential part of the global energy market. LNG is principally used for transporting natural gas to hard-to-reach markets, where it is ‘regasified’ and then distributed as pipeline natural gas.
LNG starts life as an approximately 95% methane natural gas (predominantly methane, CH4) that is then cooled down (through a cycle of compression, condensation, expansion and evaporation) to -160°C, at which point it transforms to a liquid form.
The liquefication process involves the removal of particular components, such as dust, acid gases, helium, water, and heavy hydrocarbons, that would potentially create difficulties later down the line.
Not only is transportation of LNG easier in liquid format, but it is also more practical as once it has been liquified, natural gas is less voluminous and can be stored in a volume 1/600th as large. This allows it to be stored and transported safely in very large quantities.
Efficient transportation of LNG is essential. The easiest and most economical method of transportation is to ship it via LNG tankers that have thermally insulated tanks, that have been specially designed to maintain the natural gas in a liquid form.
As an example of the benefits of using LNG as opposed to other fuel supplies, in 2019 the AIDA Nova cruise ship was fitted with low-temperature tanks for liquefied natural gas. By converting from heavy oil to LNG propulsion, the ships emission of CO2 is reduced by up to 25% and other emissions are also lowered significantly.