Thermodynamic Analysis of an Integrated System for LNG Regasification and Power Production

Today, natural gas is used in domestic as well as for various industrial purposes. Natural gas being found in remote and specific locations, it has to be transported for long distance before supplied to customers around the globe. Producing liquefied natural gas (LNG) is a highly energy intensive process and consumes about 10 – 15% of total energy spent for LNG production.  However, eventually for the end use, natural gas need to be supplied in its gaseous form and the process is known as regasification.  Energy spent for the liquefaction of natural gas is wasted unless it is recovered during this regasification process. Cold exergy of LNG can be utilized for improving the performance of Rankine cycle based power plants. This paper has proposed a power system in which low temperature waste heat can be effectively recovered and LNG can be vaporized to atmospheric conditions. The system consists of propane Rankine cycle and LNG power generation system using direct expansion. It is modeled by considering mass and energy balance in each component. The result shows that proposed cycle has good in performance and gives an exergy efficiency of 37.25 %. The effect of key parameters on system performance was also investigated .