Exergy and industrial ecology—Part 1: An exergy-based definition of consumption and a thermodynamic interpretation of ecosystem evolution

Abstract

A central theme of industrial ecology (IE) is the idea of using the cyclical resource-use patterns observed in mature, biological ecosystems as a model for designing increasingly mature ‘industrial ecosystems’ whose productivity relies less on resource extraction and waste emission. In this two part series, we will use a thermodynamic interpretation of ecosystem evolution to strengthen this biological–industrial (B–I) ecosystem analogy. We begin by describing limitations in the current analogy and discussing resulting implications for the development and implementation of IE principles. We propose that these limitations arise largely from a poor definition of resource consumption. We then show that defining resource consumption as a process of removing exergy from a resource provides a basis for interpreting ecosystem evolution as a process of allowing consumption to occur with decreasing levels of depletion, i.e., a process of ‘de-linking’ consumption and depletion. We use thermodynamic principles to deduce the limitations and interrelation of several strategies for de-linking consumption and depletion. Lastly, we explore the benefits and limitations of using the proposed interpretation of ecosystem evolution as an analogy for the development of industrial systems.