Evaluation of novel process configurations for coproduction of LNG and NGL using advanced exergoeconomic analysis

Abstract

Advanced exergoeconomic analysis is applied on two novel process configurations for co-production of LNG and NGL. Dual mixed refrigerant (DMR) and mixed fluid cascade (MFC) refrigeration systems are used for supplying the required refrigeration. Based on the avoidable cost of exergy destruction in DMR process configuration, C-300 compressor with 504.43($/h) and in MFC process configuration, C-200A compressor with 251.05($/h) should be modified first. Based on the avoidable endogenous/exogenous part, three strategies are proposed for reducing exergy destruction cost in the process components. Cost of exergy destruction and investment in most of the process components are endogenous. So interactions among the components in these processes is not strong. Investment cost of turbo expander and compressors are unavoidable due to technological and economic limits while air coolers and heat exchangers have potential for improvement. Cost of exergy destruction of the air coolers and heat exchangers are unavoidable while turbo expander and compressors are avoidable.