Patrick A. Wäger

RoHS - regulated substances in mixed plastics from waste electrical and electronic equipment

This paper summarizes the findings of a research study, which was commissioned by the WEEE Forum to contribute to a formulation of normative requirements with respect to depollution of WEEE. Two main questions are addressed: (i) What are the concentrations of substances regulated by the Directive 2002/95/EC of the European Parliament and of the Council on the restriction of the use of certain hazardous substances in electrical and electronic equipment (RoHS Directive) in mixed plastics from selected WEEE categories and products?, and (ii) What are the implications for an environmentally sound recovery of plastics from WEEE? The study included 53 sampling campaigns for mixed plastics from WEEE. The samples were analysed with regard to flame retardants (PentaBDE, OctaBDE, DecaBDE, DecaBB) and heavy metals (cadmium, chromium, mercury and lead) regulated in the RoHS Directive. Besides these substances, other brominated flame retardants known to occur in electronics (HBCD, TBBPA) as well as the total bromine and phosphorus contents were considered. Results were evaluated with regard to the maximum concentration values defined in the Directive.

Life cycle assessment of post-consumer plastics production from waste electrical and electronic equipment (WEEE) treatment residues in a Central European plastics recycling plant

Plastics play an increasingly important role in reaching the recovery and recycling rates defined in the European WEEE Directive. In a recent study we have determined the life cycle environmental impacts of post-consumer plastics production from mixed, plastics-rich WEEE treatment residues in the Central European plant of a market-leading plastics recycler, both from the perspective of the customers delivering the residues and the customers buying the obtained post-consumer recycled plastics. The results of our life cycle assessments, which were extensively tested with sensitivity analyses, show that from both perspectives plastics recycling is clearly superior to the alternatives considered in this study (i.e. municipal solid waste incineration (MSWI) and virgin plastics production). For the three ReCiPe endpoint damage categories, incineration in an MSWI plant results in an impact exceeding that of the examined plastics recycling facility each by about a factor of 4, and the production of virgin plastics has an impact exceeding that of the post-consumer recycled (PCR) plastics production each by a factor of 6-10. On a midpoint indicator level the picture is more differentiated, showing that the environmental impacts of the recycling options are lower by 50% and more for almost all impact factors. While this provides the necessary evidence for the environmental benefits of plastics recycling compared to existing alternatives, it can, however, not be taken as conclusive evidence. To be conclusive, future research will have to address the fate of hazardous substances in the outputs of such recycling systems in more detail.

The Transition from Desktop Computers to Tablets: A Model for Increasing Resource Efficiency

Sales statistics of computing devices show that users are not replacing units one by one, but rather adding additional devices to their hardware portfolios. This chapter describes the outcomes of a first attempt to quantify the ecological implications of changes in the use of ICT hardware for computing services by using LCA and applying three different perspectives ranging from individual devices to global sales of desktop, laptop, and tablet computers. In particular, it addresses the question of which effect actually predominates: the increase in efficiency induced by the emergence of new technologies or the growing energy consumption due to an increased number of devices combined with a higher utilization rate by individual users. The comparison shows a clear reduction of the environmental impact per hour of active use; and the smaller the device, the smaller the impact due to the active use of the device. However, when the evolution in the use of these kinds of devices is taken into account as well, the picture changes. The calculations show that the higher in-use efficiency of individual devices is fully compensated by the efforts for the production of the increasing number of devices in use, without even considering increased use time. If increased use intensity is assumed as well, a clear increase of the overall impact per day can be observed.

The Material Basis of ICT

Technologies for storing, transmitting, and processing information have made astounding progress in dematerialization. The amount of physical mass needed to represent one bit of information has dramatically decreased in the last few years, and is still declining. However, information will always need a material basis. In this chapter, we address both the upstream (from mining to the product) and the downstream (from the product to final disposal) implications of the composition of an average Swiss end-of-life (EoL) consumer ICT device from a materials perspective. Regarding the upstream implications, we calculate the scores of the MIPS material rucksack indicator and the ReCiPe mineral resource depletion indicator for selected materials contained in ICT devices, namely polymers, the base metals Al, Cu, and Fe, and the geochemically scarce metals Ag, Au, and Pd. For primary production of one kg of raw material found in consumer ICT devices, the highest material rucksack and resource depletion scores are obtained for the three scarce metals Ag, Au, and Pd; almost the entire material rucksack for these metals is determined by the mining and refining processes. This picture changes when indicator scores are scaled to their relative mass per kg average Swiss EoL consumer ICT device: the base metals Fe and in particular Cu now score much higher than the scarce metals for both indicators. Regarding the downstream implications, we determine the effects of a substitution of primary raw materials in ICT devices with secondary raw materials recovered from EoL consumer ICT devices on both indicator scores. According to our results, such a substitution leads to benefits which are highest for the base metals, followed by scarce metals. The recovery of secondary raw materials from EoL consumer ICT devices can significantly reduce the need for primary raw materials and subsequently the material rucksacks and related impacts. However, increased recycling is not a panacea: the current rapid growth of the materials stock in the technosphere necessitates continuous natural resource depletion, and recycling itself is ultimately limited by thermodynamics.

Challenges for LCAs of Complex Systems: The Case of a Large-Scale Precious Metal Refinery Plant

Umicore Precious Metal Refining (UPMR) runs a high-tech industrial metal refinery which recovers 17 different metals from end-of-life consumer products and from by-products of the non-ferrous industry. We present an approach for an attributive gate-to-gate LCA study of this system, which is characterised by multi-input/multi-output processes, changing feed compositions and time lags. We propose five assumptions to reduce the complexity of the highly dynamic system. We compiled inventory data for over thirty sub-processes and allocated it over the metals passing the sub-process by either a mass-based or metal revenue based allocation. The exemplary results for rhodium, platinum, tellurium and copper (impact assessment method: global warming potential) show a high dependence of allocation choice and different patterns of the metals for metal revenue based allocation due to the high volatility of prices.