Life cycle cost analysis of distributed versus centralized plastic sorting and recycling

Miniaturizing plastic recycling through distributed systems has been viewed as a way to manage waste closer to the source while minimizing logistics requirements. The environmental performance of distributed manufacturing and waste management systems has been evaluated, but few studies have measured the financial performance. This study combines life cycle costing and hybrid simulation modeling to compare the net present value of small-scale distributed versus large-scale centralized systems of sorting and recycling plastic bottles and takeaway containers disposed in Singapore over 7 years. The results showed that distributed systems face a net financial loss at existing prices of SGD80–120/tonne recycled pellets. This is because of the high operation costs, particularly the labor costs due to the reliance on manual sorting. Despite being closer to the waste sources, distributed scenarios have higher fuel costs due to the poorer fuel efficiency of commercial vans compared to the larger trucks in the centralized scenarios. To improve the financial performance of distributed small-scale plastic recycling systems, it is generally recommended that small-scale sorting facilities reduce the reliance on manual labor; the smaller trucks should have higher fuel economies than conventional large waste hauling trucks; the number of small-scale facilities set up should match the amount of waste to be converted; and the price of the recycled pellets should be high enough to recover the high operating costs of recycling. The findings of this study provide motivation for future research in evaluating the financial performance of distributed recycling of other waste streams. This article met the requirements for a gold-gold data badge JIE data openness badge described at http://jie.click/badges      

Potentials and limits of mechanical plastic recycling

Plastics consumption continues to steeply increase worldwide, while resultant waste is currently mostly landfilled, discarded to the environment, or incinerated. This significantly contributes to global warming and causes negative health and ecosystem effects. Increasing the circularity of plastics can reduce these impacts. This study investigated to which extent plastics' circularity can be increased by mechanical recycling. For this purpose, future scenarios involving increased waste collection, improved product design, and improved waste sorting were assessed. The system studied consists of 11 plastic types in 69 product groups consumed and arising as waste in Switzerland. By means of a material flow analysis, the amounts of consumption, waste, and secondary material utilizable in product manufacturing were quantified for the year 2040. For the waste not mechanically recycled, treatment situations mainly involving energy recovery in waste-to-energy plants and cement kilns were modeled. A life cycle assessment of the complete plastic material flow system was conducted. We found that the mechanical recycling rate calculated based on the utilizable secondary material can be increased to up to 31%. This can lower the plastic carbon footprint by one quarter (1.3% of today's total Swiss carbon footprint) compared to no recycling. Important barriers to a further increase of the recycling rate were inaccessibility, the large diversity of plastic grades, and contamination. The remaining impact at maximum recycling is mainly caused by polyurethanes, polypropylene, and polystyrene production. In conclusion, the potential of mechanical plastic recycling is limited, but it can, as one of several measures, contribute to combating climate change.     

Toward Estimating Displaced Primary Production from Recycling: A Case Study of U.S. Aluminum

Recycling materials from end‐of‐life products has the potential to create environmental benefit by displacing more harmful primary material production. However, displacement is governed by market forces and is not guaranteed; if full displacement does not occur, the environmental benefits of recycling are reduced or eliminated. Therefore, quantifying the true “displacement rate” caused by recycling is essential to accurately assess environmental benefits and make optimal environmental management decisions. Our 2016 article proposed a market‐based methodology to estimate actual displacement rates following an increase in recycling or reuse. The current article demonstrates the operation, utility, and challenges of that methodology in the context of the U.S. aluminum industry. Sensitivity analyses reveal that displacement estimates are sensitive to uncertainty in price elasticities. Results suggest that 100% displacement is unlikely immediately following a sustained supply‐driven increase in aluminum recycling and even less likely in the long term. However, zero and even negative displacement are possible. A variant of the model revealed that demand‐driven increases in recycling are less likely than supply‐driven changes to result in full displacement. However, model limitations exist and challenges arose in the estimation process, the effects of which are discussed. We suggest implications for environmental assessment, present lessons learned from applying the estimation methodology, and highlight the need for further research in the market dynamics of recycling.     

Material Recycling and the Myth of Landfill Diversion

Proponents of material recycling typically point to two environmental benefits: disposal (landfill/incinerator) reduction and primary production displacement. However, in this paper we mathematically demonstrate that, without displacement, recycling can delay but not prevent any existing end‐of‐life material from reaching final disposal. The only way to reduce the amount of material ultimately landfilled or incinerated is to produce less in the first place; material that is not made needs not be disposed. Recycling has the potential to reduce the amount of material reaching end of life solely by reducing primary production. Therefore, the “dual benefits” of recycling are in fact one, and the environmental benefit of material recycling rests in its potential to displace primary production. However, displacement of primary production from increased recycling is driven by market forces and is not guaranteed. Improperly assuming all recycled material avoids disposal underestimates the environmental impacts of the product system. We show that the potential magnitude of this error is substantial, though for inert recyclables it is lower than the error introduced by improperly assuming all recycled material displaces primary material production. We argue that life cycle assessment end‐of‐life models need to be updated so as not to overstate the benefits of recycling. Furthermore, scholars and policy makers should focus on finding and implementing ways to increase the displacement potential of recyclable materials rather than focusing on disposal diversion targets.     

A consequential approach to life cycle sustainability assessment with an agent-based model to determine the potential contribution of chemical recycling to UN Sustainable Development Goals

Chemical recycling (CR) could support a circular approach for municipal solid waste (MSW) treatment. In promoting the recirculation of recyclable carbon-containing waste as secondary feedstock for chemical production, it could contribute to resource conservation, emissions reduction, and supply security. To evaluate CR's contribution to the transition from a linear to a circular carbon economy—and correspondingly to the achievement of environmental, economic, and social sustainability as indicated in the UN Sustainable Development Goals (UN-SDGs)—this study builds on extant literature of life cycle sustainability assessment (LCSA) to investigate consequential environmental, economic, and social CR impacts. Specifically, an integrated approach whereby process-based life cycle assessment, techno-economic analysis, and social indicators are linked in the framework of an agent-based model is developed to investigate sustainability consequences of CR via gasification of residual MSW in Germany. Results suggest that CR contributes to reducing climate change and to addressing terrestrial acidification and fossil resource scarcity. However, its deployment will be associated with significant system costs. Hence, to promote CR implementation, measures such as obliging direct waste incineration to trade CO₂ certificates—provided that certificate prices increase sharply in the future—as well as implementing a recycling rate are found to be necessary to gap economic disadvantages. This study not only contributes to extending life cycle approaches for LCSA methodologically, it furthermore provides valuable insights into temporal and spatial interactions in waste management systems to inform science, industry, and politics about the sustainability impacts of CR on the achievement of the UN-SDGs. This article met the requirements for a gold-gold JIE data openness badge described at http://jie.click/badges .      

Economic assessment and carbon footprint of recycling rare earths from magnets: Evaluation at lab scale paving the way toward industrialization

Project EXTRADE developed an innovative process for recycling rare earths (RE) from permanent magnets used in small applications. To assess the potential of further research from lab scale toward industrialization, this study performs economic and environmental evaluations. Because data are incomplete at current levels of process development, this study propagates uncertainty into the results. Results show that the EXTRADE process, as a complement to the Hard Disk Drive (HDD) waste management system currently in operation in France, could be both economically profitable and beneficial in terms of climate change. However, at this stage of development the price of output products is a key determinant of the economic profitability while still particularly uncertain. Also, the EXTRADE process may offer a climate change benefit due to the substitution of recycled RE oxides for those produced from primary resources (80% chance to be superior to 990 tonnes CO₂‐eq over 5 years). The amount of the waste recycled is another key, uncertain parameter regarding both the environmental and economic benefits provided by the process.     

Toward a low-carbon and circular building sector: Building strategies and urbanization pathways for the Netherlands

Buildings are an important part of society's environmental impacts, both in the construction and in the use phase. As the energy performance of buildings improve, construction materials become more important as a cause of environmental impact. Less attention has been given to those materials. We explore, as an alternative for conventional buildings, the use of biobased materials and circular building practices. In addition to building design, we analyze the effect of urbanization. We assess the potential to close material cycles together with the material related impact, between 2018 and 2050 in the Netherlands. Our results show a limited potential to close material cycles until 2050, as a result of slow stock turnover and growth of the building stock. At present, end-of-life recycling rates are low, further limiting circularity. Primary material demand can be lowered when shifting toward biobased or circular construction. This shift also reduces material related carbon emissions. Large-scale implementation of biobased construction, however, drastically increases land area required for wood production. Material demand differs strongly spatially and depends on the degree of urbanization. Urbanization results in higher building replacement rates, but constructed dwellings are generally small compared to scenarios with more rural developments. The approach presented in this work can be used to analyze strategies aimed at closing material cycles in the building sector and lowering buildings' embodied environmental impact, at different spatial scales.     

Evaluating the cascading-use of wood furniture: How value-retention processes can contribute to material efficiency and circularity

As utilized technical products, durable wood furniture plays an important role in a future circular economy (CE). However, contemporary CE literature predominantly focuses on wood's biochemical properties and its potential as a consumable material within the bio-cycle. This perspective prevents meaningful consideration of CE strategies for the wood products sector, particularly for value-retention processes (VRPs), including reuse, repair, and refurbishment. We adapt and apply the VRP model introduced by the UN International Resource Panel (IRP) to wood furniture products to quantify select environmental benefits made possible through cascading-use, via VRPs (vs. new manufacturing). Unlike traditional life cycle assessment (LCA), this model accounts for impacts incurred and avoided through product life-extension and VRPs, relative to conventional systems of new manufacturing, disposal, and replacement. Three case studies of wood-based chairs are conducted to demonstrate this new application of the VRP model to compare the relative environmental impacts associated with wood furniture that is diverted to cascading-use, prior to recycling. In collaboration with industry partners, new material requirements (kg/unit), energy requirements (kWh/unit), emissions (kg CO2-e./unit), and waste generation (kg/unit) were calculated for newly manufactured chairs (OEM new) and subsequent cascading-use via reuse, repair, and refurbishment. The differing degrees of environmental impact avoidance and material efficiency are presented for each case study product and VRP, to provoke discussion and future research regarding the effective and optimal utilization of technical, durable wooden furniture within a CE.     

Management into the Development Strategies of Urbanizing Regions in Asia: Implications of Urban Function, Form, and Role

The way urbanization unfolds over the next few decades in the developing countries of Asia will have profound implications for sustainability. One of the more important opportunities is to guide urbanization along pathways that begin to uncouple these gains in well-being from rising levels of energy use. Increasing energy use for transport, construction, climate control in houses and offices, and industrial processes is often accompanied by increasing levels of atmospheric emissions that impact human health, ecosystem functions, and the climate system. Agriculture, forestry, and animal husbandry alter carbon stocks and fluxes as carbon dioxide, methane, and black carbon. In this article we explore how carbon management could be integrated into the development strategies of cities and urbanizing regions. In particular, we explore how changes in urban form, functions, and roles might alter the timing, aggregation, spatial distribution, and composition of carbon emissions. Our emphasis is on identifying system linkages and points of leverage. The study draws primarily on emission inventories and regional development histories carried out in the regions around the cities of Manila, Jakarta, Ho Chi Minh City, New Delhi, and Chiang Mai. We find that how urban functions, such as mobility, shelter, and food, are provided has major implications for carbon emissions, and that each function is influenced by urban form and role in distinct ways. Our case studies highlight the need for major "U-turns" in urban policy.     

Life Cycle Assessment of a Magazine,Part I: Tablet Edition in Emerging and Mature States

Information and communication technology (ICT) is providing new ways to access media content. ICT has environmental benefits and burdens. The overall goal of the present study was to assess the environmental impacts of production and consumption of magazines read on tablets from a life cycle perspective. Important goals were to identify the activities giving rise to the main impacts and the key factors influencing the overall environmental impacts. Data gaps and uncertainties were also addressed. The results are compared against those for the print edition of the magazine in a separate article (part 2). The methodology used in the study was life cycle assessment. The environmental impacts assessed included climate change, cumulative energy/exergy demand, metal depletion, photochemical oxidant formation, particulate matter formation, terrestrial acidification, freshwater/marine eutrophication, fossil depletion, human toxicity, and ecotoxicity. The results indicate that content production can be the major contributor to environmental impacts if readers are few (as for the emerging version of the magazine studied). Assuming more readers (more mature version) or a larger file size for the tablet magazine, electronic storage and distribution may be the major contributor. Thus, in contrast to previous studies on electronic media, which reported a dominant impact of the use phase, this study found a higher impact for content production (emerging version) and electronic storage and distribution (mature version). However, with inefficient, low overall use of the tablet with a mature version of the tablet magazine, the greatest impact was shown to come from the reading activity (i.e., the use phase). In conclusion, the relative impacts of the tablet magazine would decrease considerably with high numbers of readers, their efficient use of the tablet (i.e., for many purposes over a long life of the device), and a smaller magazine file.     

Differences in Perception of Extended Producer Responsibility and Product Stewardship among Stakeholders: An International Questionnaire Survey and Statistical Analysis

Different perceptions of the concept of extended producer responsibility and product stewardship (EPR/PS) have tended to lead to prolonged policy disputes and have likely affected the design of EPR/PS policies. We therefore surveyed stakeholders’ perceptions of the concept of EPR/PS, including its aims, application, and rationales, and analyzed 376 responses with regression analysis and cluster analysis. The results clearly demonstrated the diversity in stakeholders’ perceptions and identified/confirmed several patterns between stakeholders’ perceptions and attributes. Concerning aims, our analysis showed that stakeholders from middle‐/low‐income countries placed more importance on proper treatment and waste reduction in EPR/PS policy, while those from Europe, North America, Japan, and the rest of Asia had different perceptions on seven aims of EPR/PS, especially for increasing collection and shifting responsibility to producers, and paid varying attention to upstream and downstream improvement (e.g., better product design and recycling, respectively). Our analysis also confirmed that respondents perceiving lack of capability of local governments regarding waste management advocated EPR/PS more and respondents positive about information acquisition put more importance on physical responsibility. The largest contributing variables to the perception of EPR/PS were 14 specific EPR/PS mechanisms/issues, suggesting that discussion about specific mechanisms of EPR/PS policy is a key if common and better understandings of the EPR/PS concept are to develop. The dominant rationale of EPR/PS agreed upon by the respondents was producers’ capability, but the concept of beneficiary bears was also supported by 58% of respondents, especially by national governments and North Americans. Finally, implications of the results for EPR/PS policy development were discussed.     

Life Cycle Assessment of a Magazine,Part II: A Comparison of Print and Tablet Editions

The rapid development of information and communications technology (ICT) is providing new ways to access media content. Electronic media are sometimes more advantageous from an environmental perspective than paper‐based media solutions, but ICT‐based media can also bring environmental burdens. This study compared the potential environmental impacts in a life cycle perspective of a print edition of a magazine and that of its electronic edition read on a tablet device. Important objectives were to identify activities giving rise to the main environmental impacts for both the print and tablet editions, determine the key factors influencing these impacts, and address data gaps and uncertainties. A detailed assessment of the tablet edition is provided in a previous article (part 1), whereas this article compares it with the print edition. The methodology used was life cycle assessment and the environmental impacts assessed included climate change, cumulative energy/exergy demand, metal depletion, photochemical oxidant formation, particulate matter formation, terrestrial acidification, freshwater eutrophication, marine eutrophication, and fossil depletion. Use of different functional units to compare the print and tablet editions of the magazine resulted in different relative environmental impacts. In addition, emerging (low number of readers and low reading time per copy) and mature (higher number of readers and higher reading time per copy) tablet editions yielded varying results. The emerging tablet edition resulted in higher potential environmental impacts per reader than the print edition, but the mature tablet edition yielded lower impacts per reader in half the impact categories assessed. This illustrates the importance of spreading the environmental impacts over a large number of readers. The electricity mix used in product system processes did not greatly affect the results of tablet/print comparisons, but overall number of readers for the tablet edition, number of readers per copy for the print edition, file size, and degree of use of the tablet device proved crucial for the comparison results.