About LNG energy utilization efficiency estimation

The amount of LNG demand is continuously increasing now. The main disadvantage of the LNG in comparison with traditional NG transportation is a fact that to liquefy LNG it is necessary to spend energy and then add some heat to re-gasify it. Regasification process is usually carried out with loss of the low-temperature potential, which is created during LNG liquefaction. This potential can be utilized for energy generation, and the realization of potential utilization may be executed in several ways: by heat rejection from thermodynamic cycle and thus increasing its efficiency, preliminary pressurizing of LNG by pump or thermal compression and its further expansion in turbines or combinations of these two methods. This article deals with the estimation of maximal work which can be obtained from re-gasification of 1 kg of LNG by these methods. The calculations show that most efficient methods are heat rejection and thermal compression. (C) 2016 The Authors. Published by Elsevier Ltd.