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Introduction The need for a circular economy has gained large importance and is considered one of the top priorities in the Sustainable Development Goals (SDG) formulated by the European Union (EU) (EC, 2015). In this context, material recycling of post-consumer waste is seen as the preferred option to high value discarded items. However, one of the challenges to the circular economy is the presence of impurities within the recyclables. Indeed, impurities could re-enter the product's life cycle along with the targeted material (risk-cycling). Therefore, information on levels of impurities in recyclable waste fractions is needed to quantify and address the problem. Among recyclable fractions, wood waste occurs in large amounts from applications such as packaging, buildings, construction, demolition, and furniture. The main end of life option for wood waste has historically been incineration, due to its high calorific value. However, cascading the resource's uses is necessary in order to apply a circular economy approach and extend the product's life cycle. Therefore, recycling is the preferred treatment option for post-consumer wood waste, which is generally chipped and processed to produce particleboard. Since wood waste is often associated with material and chemical impurities (Edo et al., 2016), investigations are needed to ensure high quality, clean and safe recycling loops. The aim of this study is to evaluate levels of material and chemical impurities in post-consumer wood waste from a recycling perspective. Material and Methods Data on composition of impurities within wood waste come from a sampling campaign from recycling centers in Denmark. Material impurities were investigated, and were found to account up to 22% of the collected material. Concentration levels of selected chemical elements and persistent organic pollutants were analysed. Their concentration appeared to vary according to application use of the waste wood, being generally higher for wood waste from the demolition and the furniture sector. The presence of chemical contaminants was linked to material impurities as well as to treatment of the wood items with preservatives, paints, and finishes. Results were used to investigate the consequences that presence of such impurities have on recycling chain of wood waste. Results and Conclusions The presentation will address preliminary findings from presence of material and chemical impurities in the wood waste as a basis to frame the challenge that risk-cycling may constitute to a (almost) closed circular economy.

Biofuels are likely to play an increasingly important role in the transportation sector in the coming decades. To ensure the sustainability of the biofuel chain, regulatory criteria and reduction targets for greenhouse gases (GHG) emissions have been defined in different legislative frameworks (e.g. the European Renewable Energy Directive, RED). The provided calculation methods, however, leave room for interpretation regarding methodological choices, which could significantly affect the resulting emission factors. In this study, GHG reduction factors for a range of biofuels produced in a Danish biorefinery system were determined using five different emission allocation principles. The results show that emission savings ranged from -34 % to 71 %, indicating the need for a better definition of regulatory calculation principles. The calculated emission factors differed significantly from default values provided in the literature, suggesting that case-specific local conditions should be taken into consideration. A more holistic LCA-based approach proved useful in overcoming some of the issues inherent in the regulatory allocation principles. On this basis, indirect land use change (ILUC) emissions were shown to have the same magnitude as the direct emissions, thus indicating that the overall system should be included when assessing biofuel sustainability criteria.

Recycling of plastic from household waste (HHW) is crucial in the transition towards a circular plastic economy. Plastic from HHW consists of numerous immiscible polymers, product types and product designs (e.g. colour, polymer separability), which often lead to considerable physical losses during sorting, and low-quality recycled plastic. Consequently, recycling initiatives have been proposed to enhance the quantity and quality of plastic recycling from HHW. To quantify the potential effects of such initiatives, a detailed composition of plastic waste is necessary. The aim was to provide such detailed composition of Danish source-separated rigid plastic waste, including information regarding the polymer of the main product component, product type, polymer design and separability as well as colour. The potential effects on recycled quantity and quality from implementing selected recycling initiatives were quantified and recommendations provided. PET, PE and PP made up >90% of the source-separated plastic and both food- and non-food packaging existed in all three polymers. In total, 10–11% of the plastic was black, and around 44% consisted of multiple polymers, of which one-third was non-separable. Initiatives improving product design for recycling will likely result in increased quantity of recycled plastic. By effectively separating food from non-food packaging, e.g. by introducing two bins in the households or politically aligning polymers and product types (all food packaging in PET and PP, all non-food packaging in PE), 39–63% of the waste could potentially be recycled in a closed loop into food-grade quality packaging. The overall highest benefits were reached by combining initiatives.

Cascading utilisation of post-consumer wood waste has recently gained increasing attention in the European Union, aiming for a society in which the resource's properties are optimized through sequential uses. To date, material utilisation of wood waste has been limited to particleboard production, with additional niche alternatives being restricted by quality requirements for wood waste. In this consequential life cycle assessment focusing on post-consumer wood collected at Danish recycling centres, Global Warming Potential (GWP) impacts from quality-driven choices for cascading management of wood waste were compared with those from handling mixed wood waste qualities. GWPs were modelled by considering the dynamic profile of greenhouse gas emissions (including biogenic carbon dioxide) for two time horizons (100 and 500 years). The robustness of the results was tested by varying modelling assumptions with respect to electricity system, wood sourcing and associated rotation period, and impacts from indirect land use changes. The results demonstrated that valuing quality over quantity in wood waste management can ensure larger GWP savings, especially if recycling applications have a long lifetime and/or substitute energy-intensive products; such results were confirmed under all scenario analyses. Inclusion of land use changes credited land-intensive products. More cascade steps of the wood waste resource ensured larger savings; however, assumptions on the electricity mix, on the source of the wood alongside the choice of the time horizon for GWP greatly influenced the results on cascading management.

Bisphenol A (BPA) is an industrial chemical used as an additive in conventional point-of-sale thermal paper receipts. Due to BPA being an endocrine disruptor and a substance of very high concern, the European Union (EU) has proposed to ban its use in thermal paper from 2020. Potential similarities in toxicological profiles have raised concerns that the use of bisphenol S (BPS) as a substitute for BPA may result in yet another situation of a problematic chemical being distributed in consumer products. This study provides a comprehensive evaluation of the current knowledge of BPA and BPS use in thermal paper and, based on dynamic material and substance flow modeling, quantifies potential effects of the BPA ban on future BPA and BPS flows within the European paper cycle. Based on available data and the modeling of BPA and BPS flows, approximately 200 t of BPS are estimated to be present in the current European paper cycle. The modeling further demonstrated that by substituting 50% of BPA, BPS amounts in the European paper cycle would increase more than fivefold over a modeling period of 60 years. In the same time, more than 90 t of BPA would still be circulated in European paper products. BPA alternatives other than BPS should receive additional attention, as very limited quantitative data currently exist. The results of this study quantitatively demonstrate that chemical bans alone are not sufficient to ensure clean material cycles, and so the effective regulation of potential substitutes needs to be implemented in parallel.

Introduction Wood waste is a valuable material with a potential for both energy and material utilization. However the circular economy approach adopted by the European Union clearly favours material recycling over energy recovery, aiming for a society where resource utilization is optimized through sequential applications, i.e. increasing the overall lifetime of the resource and minimizing the quality loss per application ("resource cascading"). The main recycling applications for wood waste are, depending on its quality, production of particleboard, floor boards, insulation materials, wood-composite materials, and pellets. The environmental performance of wood waste recycling alternatives has been previously assessed by the scientific community in terms of Global Warming Potential (GWP), although the quality of the resource and temporal aspects of the recycling systems are generally overlooked. The aim of this study is: i) to dynamically assess the GWP of greenhouse gas (GHG) emissions of alternative wood waste cascading use systems; and ii) to discuss the role of the quality of wood waste with respect to the environmental savings that can be achieved. Material and Methods The functional unit is the management of 1 tonne of wood waste from Danish recycling centres. Fifteen scenarios were grouped into two sets reflecting whether different quality grades of the wood waste were kept together (WWmix) or separate (WWquality) during management. Four WWmix scenarios covered recycling to particleboard with one, two, three or four cascading cycles. Eleven WWquality scenarios covered the following recycling applications: particleboard, flooring, wood insulation board (WIB), wood plastic composites, and pellets; up to four recycling to particleboard iterations were included in the scenarios when possible. For the dynamic GWP, biogenic and fossil CO2 emission profiles were calculated according to Cherubini et al. (2013); accounting of other GHGs followed the approach explained in Levasseur et al. (2011). Results and Conclusions The results showed that WWquality scenarios provided larger savings than WWmix scenarios except for the pellet case; recycling to flooring and to WIB achieved the largest savings. This demonstrates that savings can be larger if i) quality-oriented recycling is chosen instead of maximizing the mass sent to recycling, ii) the recycling application is characterized by longer lifetime and/or iii) it substitutes energy-intensive materials.