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 recycling or deposition of waste. The purpose of the industrial process is the transformation of matter into materials from which useful goods are produced. The complete cycle can be described as a sequence of man-made transformations 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: negative 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 have 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 extraterrestrial negative entropy. This requires the evaluation and comparison of entropy efficiency for the production of goods with defined useful properties.