Sustainability and biophysics basis of technical and economic processes: A survey of the reconciliation by thermodynamics

In spite of the existence of a generalized debate about sustainable development, the natural constraints imposed by the irreversibility nature of technical and economic transformations are normally less discussed. The Second Law of thermodynamics (Entropy Law) reveals the unidirectional and irreversible aspect of such transformations, and it can be used as an auxiliary tool to deal with sustainability assessment. The exergy, a concept derived from entropy, can offer qualitative measurements of resources depletion and environmental impact not covered by mass or energy. This opens opportunities to enrich the sustainability discussion. The multiple interactions among the ecosystem, the economic environment and the technical level are highlighted, along with discussions about how the entropy concept has improved the description of the three levels. The aim of this paper is to review the environmental sustainability concept from the perspective of entropy law, offering a survey of relevant applications of exergy available in literature.