Entropy, transformations and sustainability of industrial life cycles

Life cycles of materials are analysed in a systematic manner as a six-stage process. It starts with primary or secondary raw materials and ends with r ecycling or deposition of waste. The purpose of the industrial process is t he transformation of matter into materials from which useful goods are prod uced. The complete cycle can be described as a sequence of man-made transfo rmations with defined changes in entropy and energy. Entropy is the measure for any type of disorder. Changes in entropy are due to separation (mining , purification: negative entropy), ordering (consolidation, construction: n egative entropy) or disordering (mixing, crushing: positive entropy). Sustainability comprises undesired, irreversible changes of our environment . It can be regarded as an inverse function of the raise in entropy. We hav e to distinguish entropy with respect to matter, energy and information. In our context, entropy changes due to different distributions of matter are of primary importance. Sustainability implies that increases in entropy due to industrial activities must be balanced, as much as possible, by extrate rrestrial negative entropy. This requires the evaluation and comparison of entropy efficiency for the production of goods with defined useful properti es.