Economic evaluation of pressurized LNG supply chain

This study developed a high-level conceptual design of a Pressurized Liquefied Natural Gas (PLNG) supply chain with marine production, transportation, and utilization steps and estimated the life cycle cost (LCC) of the chain to assess its economic feasibility. The PLNG supply chain consisted of a Floating Liquefied Natural Gas Unit (FLNG) and a LNG Shuttle-and-Regasification Vessel (SRV). Because PLNG was produced, stored, and transported at a higher temperature and pressure than ambient-pressure LNG (ALNG), the PLNG supply chain reduced production (liquefaction) and regasification costs while increasing storage and shipping costs relative to those for ALNG, mainly due to the requirement for heavy containment systems to carry the PLNG. To reduce PLNG storage and shipping costs by improving the volume efficiency of the pressure containment system, a novel concept for a prismatic pressure vessel was employed for the pressure cargo tanks. An assessment of economic feasibility estimated the normalized LCC for a range of product pressures and shipping distances. The assessment showed that PLNG was economically feasible when the PLNG pressure was 5 bar and at short shipping distances. The cost of the pressure containment system proved to be the critical cost component. A sensitivity study demonstrated that a decrease in the material cost for the containment system could significantly increase the breakeven shipping distance. Under optimum conditions, the cost for transporting PLNG was 6% less than that of transporting ALNG.