A New Double Barrier Tank for Transportation and Storage of LNG Available to Purchase

There is presently a growing demand for natural gas as a relatively clean energy resource. Major gas reservoirs are often located far away from the major consumer markets; the need for safe end efficient transport across the oceans is growing rapidly. The preferred way of storing and transporting gas from gas fields that are not connected with pipe lines is by way of cooling down the gas to liquid state (LNG), storing it in insulated tanks, transporting it onboard ships, and unloading it at terminals. Recently there has also been an interest in offshore production of LNG onboard fixed or floating platforms or on floating production ships. Good technical solutions for storage of LNG has been available for decades, but there has recently been a growing need for tanks that are suited for transportation very large ships as well as suited for offshore storage and capable of dealing with partial degrees of filling during dynamic, floating conditions. The paper describes an entirely new concept for prismatic LNG containments that is scalable and thereby suited for small as well as very large tanks, it can effectively deal with the sloshing problem during partial filling and dynamic conditions, it has a double barrier for safety, and it is self carrying without need for lateral support structures. The paper describes the conceptual ideas on which this tank is based and outlines some of the structural principles ensuring a safe design. More specifically, this performance is demonstrated through examples of analyses performed. Results from numerical analyses are presented and discussed. The safety concept and the overall performance this new tank concepts meets the requirements specified in IMO’s gas code and has been accepted as an independent tank type A according to IMO International Gas Code.