Hojat Ansarinasab - Energy Systems Engineering department, Faculty of Mahmoud Abad, Petroleum University of Technology, Mahmoud Abad, Iran.
Mahmoud Afshar - Energy Systems Engineering department, Faculty of Mahmoud Abad, Petroleum University of Technology, Mahmoud Abad, Iran.
Mehdi Mehrpooya - Hydrogen and fuel cell laboratory, Faculty of New Sciences and Technologies, University of Tehran, Tehran, Iran.

Several processes have been proposed for natural gas liquefaction due to the vast utilization of LNG as a reliable and relatively easy to use fuel. Even though the merits and demerits of different process have been studied, a dearth of comprehensive technical and economical comparative investigation of these methods makes further broad examination a necessity. This article is presented to address this necessity.  In this study, five different processes (MFC-Linde, DMR-APCI, C۳MR-Linde, SMR-APCI, and SMR-Linde) were inclusively compared and ranked considering eight most relevant indices, namely power consumption, coefficient of performance, specific energy consumption, exergy efficiency, LNG production rate, refrigerant rate, number of equipment, and energy improvement potential. The comparison and ranking of these processes were carried out by analytic hierarchy process (AHP). The results indicated that DMR-APCI process was in the first rank. In this article, the variations of model resulted in change in the impact weight of each criterion and their effect on the aggregate priority of the alternative LNG processes was also assessed.

Liquefied Natural Gas, LNG Process, Analytic Hierarchy Process, ranking