Liquefied natural gas (LNG) consists mainly of methane, artificially liquefied by cooling to −160°C — at which point the volume of gas is reduced
* “Ship-to-ship” bunkering involves ships being refuelled directly from the deck of a specialist bunkering vessel. This technology means bunkering can be undertaken when ships are moored or docked at a pier.
** MARPOL refers to the “International Convention for the Prevention of Pollution from Ships”. An amendment to the main treaty in early 2015 introduced further regulation governing the permissible amount of sulphur in marine fuels used in vessels covering Sulphur Emission Control Areas **(SECA, covering shipping zones including the Baltic Sea, the North Sea and the English Channel, where vessels are required to switch to low-sulphur fuels). With effect from 1 January 2020 the requirements of the MARPOL Convention forbidding the use of fuels with sulphur content above 0.5 percent have come into force throughout international navigation.