Conventional and advanced exergoeconomic assessments of a new air separation unit integrated with a carbon dioxide electrical power cycle and a liquefied natural gas regasification unit

• Published in: Energy conversion and management 2018-05, Vol.163, p.151-168
• Main Authors: Mehrpooya, Mehdi, Ansarinasab, Hojat, Sharifzadeh, Mohammad Mehdi Moftakhari, Rosen, Marc A.
• Format: Article
• Language: English
• Subjects: Advanced exergoeconomic; Air separation; Carbon cycle; Carbon dioxide; Compressors; Cost analysis; Cryogenic air separation; Destruction; Economic analysis; Economic conditions; Electric power; Electricity generation; Energy recovery; Exergy; Gas separation; Gasification; Heat exchangers; Investment; Liquefied natural gas; Low temperature physics; Natural gas industry; Operating costs; Parameters; Power generation; Regasification; Sensitivity analysis; Thermodynamics
• ISSN: 0196-8904; 1879-2227
• DOI: 10.1016/j.enconman.2018.02.016

[Display omitted] •Advanced exergoeconomic analysis of a novel air separation process is done.•The process includes cold energy recovery of liquefied natural gas and carbon dioxide power cycle.•The costs of exergy destruction and investment in most cases are endogenous. In this study for the first time a new air separation unit with a carbon dioxide power cycle based on cold energy recovery of liquefied natural gas is investigated by conventional and advanced exergoeconomic analyses. With conventional exergy analysis, the source of irreversibility in the process can be determined, while with advanced exergy analysis, the real potential can be determined for improving the process operating performance as well as component interactions. The exergy destruction rate and total operating cost are divided into two catagories which are sub-parts of each other: endogenous/exogenous and unavoidable/avoidable. The exergy and exergoeconomic analyses indicate that the total process cost can be decreased by improving the performance and efficiencies of compressors and heat exchangers. This is because these types of process components have the largest and smallest exergoeconomic factor values, respectively. Results of the advanced exergy and exergoeconomic analyses demonstrate that, when considering the avoidable endogenous investment cost rate, compressors have priorities for modification. Also, based on the avoidable endogenous cost rate, one of the heat exchangers should be modified at first. The exergy destruction and investment cost rates in most of the process components are endogenous. A sensitivity analysis is performed to evaluate the effects of economic and thermodynamic parameters on the advanced exergoeconomic parameters. It is concluded that the configuration of the process components has a significant impact on their costs.