French engineering and technology company GTT (Gaztransport & Technigaz SA) has recently received an Approval in Principle (AIP) from Bureau Veritas and Lloyd’s Register for its 4,000 m3 Bunkering Ship concept, using the Mark III Flex Cargo Containment system in tanks which can be operated with a vapour pressure of up to 2 barg.
Increasing the upper limit on the pressure value to 2 barg gives more operational flexibility, especially noticeable for BOG management during loading and bunkering operations. Vapour can be buffered and condensed in the tanks to help the fuelled ship or feeding facility handle the excess vapour. When needed, condensation is performed by spraying LNG into the vapour phase.
In addition, the duration of bunkering operations is optimized by increasing loading flow rates.
Finally, during voyage and stand-by mode, the time before gas pressure reaches the upper limit is longer. This improves the holding time when there is no BOG consumption and reduces the use of any possible reliquifaction plant, thereby diminishing costs.
This development will contribute to the current development of LNG as a fuel market. Further studies are carried out with NO96 technology and also for bunker tanks for LNG Fuelled Vessels.