Thermodynamic metrics for measuring the “sustainability” of design for recycling

Abstract

In this article, exergy is applied as a parameter to measure the “sustainability” of a recycling system in addition to the fundamental prediction of material recycling and energy recovery, summarizing a development of over 20 years by the principal author supported by various co-workers, Ph.D., and M.Sc. students. In order to achieve this, recyclate qualities and particle size distributions throughout the system must be predicted as a function of product design, liberation during shredding, process dynamics, physical separation physics, and metallurgical thermodynamics. This crucial development enables the estimation of the true exergy of a recycling system from its inputs and outputs including all its realistic industrial traits. These models have among others been linked to computer aided design tools of the automotive industry and have been used to evaluate the performance of waste electric and electronic equipment recycling systems in The Netherlands. This paper also suggests that the complete system must be optimized to find a “truer” optimum of the material production system linked to the consumer market.