Assessment of LNG Regasification Systems With Cogeneration

Abstract

Natural gas is usually transferred to consumers through pipelines, which may cover distances of thousands of kilometers. In some cases, however, when the path of the pipelines crosses seas or countries where the politic situation does not ensure a continuous and reliable flow, other means of transportation are preferred. In these cases, the natural gas is liquefied and transported in tankers, which load the tanks at liquefaction plants and discharge them at regasification plants. This gives a considerable chance to differentiate supply sources and allows gas imports from producing countries that are otherwise inaccessible via pipeline. The aim of this paper is the study of systems, which carry out liquefied natural gas (LNG) vaporization using cogenerative solutions. The following configurations were studied in particular: • Gas-steam combined cycles; • Closed gas-gas combined cycles using three different working fluids. Two typical plant sizes and two gas pressure sendout levels (7.3 MPa for long distance pipeline networks and 2.5 MPa for terminals linked to power production plants with combined cycles) have been analyzed. The suggested solutions have been optimized, and performance calculated. The discussion is completed by a simplified economic analysis.