Amirhossein Yazdaninia - Institute of Liquefied Natural Gas (ILNG), School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran
Ali Vatani - Professor, Institute of Liquefied Natural Gas (I-LNG), School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran
Marzieh Zare - Research & Technology Directorate of National Iranian Gas Company
Mojgan Abbasi - Assistant Professor, Institute of Petroleum Engineering, School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran

In this study a closed nitrogen expansion cycle (Niche) has been simulated with Aspen HYSYS V۸.۴. Energy and exergy analysis were applied to evaluate the process. Results of energy analysis indicated that specific power consumption of this process is ۰.۶۸ kWh/kg LNG. The results of exergy analysis showed that exergy efficiency of Niche LNG is ۳۵.۵۱%. It is concluded there is an interaction between specific power consumption and exergetic efficiency. Moreover, the highest value of exergetic efficiency and irrevsibility belong to compressor (C۳) and gas turbine (E۱). Moreover, this process can be suitable for mini-scale LNG plants.

Closed nitrogen expansion Cycle, Exergy Analysis, Specific power consumption, LNG