The Characteristics of the Exergy Reference Environment and Its Implications for Sustainability-Based Decision-Making

Energies

Kyrke Gaudreau¹  Roydon A. Fraser² 

[1] Environment and Resource Studies, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada; E-Mail:;Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada; E-Mail:

关键词: exergy;    resource value;    waste impact;    sustainability assessment;   

DOI  :  10.3390/en5072197

来源: mdpi

【 摘 要 】

In the energy realm there is a pressing need to make decisions in a complex world characterized by biophysical limits. Exergy has been promoted as a preferred means of characterizing the impacts of resource consumption and waste production for the purpose of improving decision-making. This paper provides a unique and critical analysis of universal and comprehensive formulations of the chemical exergy reference environment, for the purpose of better understanding how exergy can inform decision-making. Four related insights emerged from the analysis, notably: (1) standard and universal chemical exergy reference environments necessarily encounter internal inconsistencies and even contradictions in their very formulations; (2) these inconsistencies are a result of incompatibility between the exergy reference environment and natural environment, and the desire to model the exergy reference environment after the natural environment so as to maintain analytical relevance; (3) the topics for which exergy is most appropriate as an analytical tool are not well served by comprehensive reference environments, and (4) the inconsistencies point to a need for deeper reflection of whether it is appropriate to adopt a thermodynamic frame of analysis for situations whose relevant characteristics are non-thermodynamic (e.g., to characterize scarcity). The use of comprehensive reference environments may lead to incorrect recommendations and ultimately reduce its appeal for informing decision-making. Exergy may better inform decision-making by returning to process dependent reference states that model specific processes and situations for the purpose of engineering optimization.

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland.