Power and LPG production with LNG import

When used in power cogeneration, Liquefied Natural Gas (LNG) is both energy efficient and can eliminate seawater or fuel gas consumption as well as the associated environmental impacts of conventional regasification processes. However, some liquefied natural gas (LNG) sources have heating values higher than current North American natural gas pipelines can allow for. LNG from these cannot be injected into gas pipelines without several heating control processing steps. This paper outlines two new technologies developed to address this issue. The first is a power cogeneration process using LNG as a heat sink. The second technology involves a fractionation process removing Liquid Propane Gas (LPG) components from imported LNG, thereby controlling heat value. Both technologies are applicable in grassroots installations as well as being suitable for retrofitting to existing LNG regasification for power generation and LPG production. It was concluded that power cogeneration with a mixed fluid power cycle recovered a significant portion of energy in LNG liquefaction plants. Additionally, it was also possible to fractionate high quality LPG from LNG at a low cost, with the residue being further re-condensed and re-utilized for power generation. It was also concluded that the LNG fractionation process would add flexibility to the LNG receiving terminals, allowing the import of lower quality LNG to North America, while also generating additional revenues from LPG production. 3 refs., 5 tabs., 6 figs