Advanced exergoeconomic evaluation of single mixed refrigerant natural gas liquefaction processes

Abstract

Conventional exergoeconomic analysis cannot recognize part of exergy destruction cost and investment cost that can be avoided. Also this analysis does not have ability to determine interactions between the components. In this study advanced exergoeconomic analysis is studied on two single mixed refrigerant processes. Costs of investment and exergy destruction are divided into avoidable/unavoidable and endogenous/exogenous parts for the components with high inefficiency. According to the avoidable exergy destruction cost in Linde process, E-1 heat exchanger with 13,232.4 ($/h) and in APCI process, C-1 compressor with 476.9 ($/h) should be considered for modification. Because these devices have higher improving potential than the other devices. The results show that costs of investment and exergy destruction in most of the process components are endogenous. Interactions between the process components do not affect the inefficiencies significantly. Cost of exergy destruction in the compressors is avoidable while investment costs in these components are unavoidable. Cost of exergy destruction in heat exchangers and air coolers is unavoidable while investment costs in these components are avoidable.