Assessment of the performance of a natural gas liquefaction cycle using natural refrigerants

Abstract

This study proposed a new cascade liquefaction cycle that uses CO2?C2H6?N2 and CO2?N2, analyzed its performance and exergy using HYSYS which is the liquefaction process simulator, and checked its applicability. The analysis results showed that the CO2?C2H6?N2 liquefaction cycle was more efficient and the CO2?N2 liquefaction cycle was better in terms of exergy loss. Furthermore, the liquefaction cycle that uses the CO2?N2 refrigerant showed lower thermal efficiency and higher compressor work than the conventional liquefaction cycle that uses C3H8?C2H4?C1H4. Thus, the proposed CO2?C2H6?N2 cycle is expected to have reasonably high thermal efficiency and potential for a high liquefaction capacity.is results showed that the CO2?C2H6?N2 liquefaction cycle was more efficient and the CO2?N2 liquefaction cycle was better in terms of exergy loss. Furthermore, the liquefaction cycle that uses the CO2?N2 refrigerant showed lower thermal efficiency and higher compressor work than the conventional liquefaction cycle that uses C3H8?C2H4?C1H4. Thus, the proposed CO2?C2H6?N2 cycle is expected to have reasonably high thermal efficiency and potential for a high liquefaction capacity.