Background of the evaluation method

The eco2 evaluation method allows the ecological-economic assessment of EoL systems with the emphasis on material recycling and final disposal and the avoidance of ecological allocation accountings necessary with LCA. The approach is based on the definition of reference systems, which define the evaluation scales and support the ecological-economic comparison of the disposal alternatives. 

The reference system and evaluation scale are defined through the following example. The method itself is based on the work of HERRMANN 2004.

The basis of the evaluation is the creation of reference systems, which serve to define the eco2 assessment scales. The idea is to have a scale from a theoretical maximum to a theoretical minimum by economic and ecological reference indicators. The reference systems refer to the material composition of the waste to be considered.

The economic reference indicator reflects the economic burden of a recycling system. The maximum achievable value is the ideal case where the materials or semi-finished secondary products are gained without any kind of cost (zero cost) and have an identical quality to primary materials. Therefore this is a theoretical value. A minimum value is not definable because cost can rise indefinitely, but a supporting point is calculated, i.e. the value occurring by a burden which is equal to the yield. The reference economic points are given on the y-axis of the Figure  "The eco2 recycling graph displaying the evaluation results".

For the ecological reference indicator, the minimum value represents a system with no ecological burden and therefore zero environmental impact. The material or semi-finished product has the same quality as the primary material or product (same reference point as economic maximum). An ecological maximum value is not definable as with the minimum economic burden. Therefore, the ecological supporting point is equal to the impacts of primary production routes for the material of its respective economic maximum. Higher impacts would cause an ecologically un-beneficial recycling system. As no ecological credits are calculated –to avoid multi life cycle allocation or system expansion- the economic gains of the secondary products are the denominator of the ecological evaluation system (X/gain on x-axis at the Figure "The eco2 recycling graph displaying the evaluation results"). Thus, various gained product qualities will be integrated into the environmental evaluation on an objective base.Together, the reference systems define the eco2 scales in a coordinate system. In the evaluation, the alternative recycling systems are modelled and their calculation results are displayed in reference systems as the Figure " Two alternative EoL options for eco2 evaluation" shows for the example.

Figure: the eco2 recycling graph displaying the evaluation results

Summary

The method of Life Cycle Engineering allows the ecological-economic evaluation of products and systems. Following the method of Life Cycle Assessment it is necessary to allocate ecologically the gains relating to the secondary materials produced with the burdens derived from the recycling and disposal processes. The results of such accountings always depend on the choice of the respective method and cannot reliably evaluate the ecological and economic quality of the selected disposal alternative. This evaluation method is applicable to all waste compositions. The focus of this work is the evaluation of electronics scrap, since this makes special demands on modelling and on evaluation. It’s important to acknowledge the high material variety at small quantities, which requires versatile and sophisticated possibilities for recycling and disposal; potentially hazardous and very valuable substances are equally present and, finally, legal regulations such as the so-called WEEE generate additional need for action in order to obtain ecologically favourable and economically sustainable solutions for recycling and disposal of electronic products.

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HERRMANN 2004

Herrmann, C.: “Ökologische und ökonomische Bewertung des Materialrecyclings komplexer Abfallströme am Beispiel von Elektronikschrott – eine Erweiterung zur