System Analysis of Waste Heat Applications With LNG Regasification

The combination of the continuously growing demand of energy in the world, the depletion of oil and its sharp price increase, as well as the urgent need for cleaner and more efficient fuels have boosted the global trade of liquefied natural gas (LNG). Nowadays, there is an increasing interest on the design philosophy of the LNG receiving terminals, due to the fact that the existing technologies either use seawater as heating source or burn part of the fuel for regasifying LNG, thus wasting the cryogenic energy of LNG and causing air pollution or harm to marine life. This investigation addresses the task of developing novel systems able to simultaneously regasify LNG and generate electric power in the most efficient and environmentally friendly way. Existing and proposed technologies for integrated LNG regasification and power generation were identified and simple, efficient, safe and compact alternatives were selected for further analysis. A baseline scenario for integrated LNG regasification and power generation was established and simulated. Various novel configurations using Rankine and Brayton cycles were created, modeled and compared to the baseline scenario in terms of LNG regasification rate, efficiency and power output. A study case with a simple and compact design was selected, preliminarily designed and analyzed. The performance and design characteristics of the study case were then compared to the baseline case. The results show that the study case results in a smaller footprint of the plant, at the same time offering a simple design solution though with lower efficiencies.