Thermodynamic analysis of integrated LNG regasification process configurations

Effective utilization of liquefied natural gas (LNG) cold energy during its regasification in both renewable and nonrenewable processes is discussed and analyzed. Conventional and non-conventional thermodynamic cycles, are described and categorized. Expressions for exergy and energy efficiencies are developed to facilitate evaluation of the processes. Finally suggestions for improving the efficiency of such systems are developed and the technical advantages and challenges are pointed out. The obtained results indicate that, among the considered cycles, the highest energy and exergy efficiencies are about 86.3% and 80.0% respectively; which is related to the combined cycles. Conversely the lowest energy and exergy efficiencies occur in other application of LNG cold energy cycles (i.e., production of hydrogen by a solar aid liquefied natural gas hybrid CO2 cycle) and Rankine cycle (i.e., CO2 transcritical geothermal power generation cycle) with the values of 7.39% and 7.95%; respectively.