In recent years, Floating LNG technology has progressed to a point that it has now become a feasible and attractive alternative to recover and monetize offshore natural gas fields. Additionally, the modular construction and assembly strategy in a shipyard makes FLNG projects less prone to onshore constraints such as permitting and a challenging construction environment. However, Floating LNG poses new challenges in terms of safety, energy efficiency, space limitations and motion. Key to this debate is the choice of liquefaction process for which the leading contenders are mixed refrigerant processes, that have light hydrocarbon inventory as principal drawback, and gaseous, reverse Brayton cycles that are handicapped by efficiency. A new liquefaction process in the latter category has been developed to increase overall efficiency among other advantages: With respect to conventional N2 cycles: Independent refrigerant cycles easy to start and operate, Possible on-stream optimization through the adjustment of composition, independently for each cycle and without refrigerant storage. With respect to other mixed refrigerant cycles: Overall reduced liquid inventory and potential for BLEVE and cold spills, Motion insensitive. This paper will: Provide a description of the new process including the thinking behind its development, Compare this process to conventional industry standard liquefaction processes in terms of process efficiency, layout and CapEx, Depict how, thanks to its simplicity and efficiency, it could be applied on many FLNG projects.
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