2 ASPECTS OF CONSUMPTION - USING AN ENERGY-BASED MEASURE OF DEGRADATION TO ADVANCE THE THEORY AND IMPLEMENTATION OF INDUSTRIAL ECOLOGY

The theory of industrial ecology (IE) and the implementation of IE str ategies are both hindered by inadequate definitions of consumption and recycling, In this paper, we introduce a definition of consumption th at separates the consumptive process into two independent, quantifiabl e phenomena: throughput and degradation. We propose that exergy remova l be used to provide a non-resource specific measure of material degra dation, We also introduce an exergy-based definition of material cycli ng -- cycling of material exergy (CME) -- and describe how it quantifi es the differences among three distinct categories of material re-use: upgrading, recirculation, and cascading, Finally, we use a simple, qu antitative example involving three methanol-water waste streams to dem onstrate exergy-based measures of consumption and material cycling. Co pyright (C) 1997 Elsevier Science B.V.