Entropy and recycling and recycling: Some examples ; Entropie et recyclage Entropie et recyclage: Quelques exemples

Abstract

Recycling helps to limit or slow down the creation of entropy of the material system; however, full recycling appears unrealistic, in particular due to physical degradation of the material.The article aims to show that very high recycling rates can only be achieved through "loop" recycling, as opposed to "cascading" recycling. Examples of this are the cases of a few materials: firstly, the case of cardboard paper in 2000 at European level. In addition, plastics and, very succinctly, aluminium. In addition, the case of glass refers to an article already published in Waste, Sciences and Techniques No 13, 1994.However, for a more comprehensive view, the analysis will have to incorporate the energy, environmental, economic and social balances. ; International audience A limit to sustainable development could be the exhaustion of some natural resources. A counterpoint is represented by a global closed-loop replenishing system, but real cycles cannot be completely closed. Concerning material systems a factor of entropy lies in losses of physical properties. However recycling is a way to reduce or slow up entropy of material systems. To reach very high recycling rates, loop recycling, and not only cascade recycling, is needed.Cases of some materials provide illustration : at first the case of paper (and cardboard) for the year 2000 at an European level (on the basis of data from the European Recovery Paper Council). The case of plastics is surveyed too ; by comparison with paper, their recycling rates are low ; however not only mechanical recycling but also chemical (feedstock) recycling and energy recovery have to be taken into account. Another case is aluminium, with a high recycling rate, and the case of glass has been considered previously (Déchets, Sciences et Techniques n° 13, 1994).For a global view, the logic in terms of material entropy would have to be supplemented by energy and environmental balances and economic and social aspects. ; Recycling helps to limit or slow down the creation of entropy of the ...