GETTING THE MOST FROM PLASTICS

Transcription

1 ENVIRONMENTAL TECHNOLOGY BEST PRACTICE PROGRAMME GETTING THE MOST FROM PLASTICS A SUSTAINABLE APPROACH TO MATERIALS MANAGEMENT The need to manage materials in terms of their primary application and life-cycle environmental impacts and their subsequent re-use and recycling is becoming ever more important. Life-cycle Product Design (LCPD) is a developing field that provides companies with methods and tools to help them select materials, products and processes with the least environmental impact over one or more life-cycles. This leaflet describes an LCPD approach and methodology, and gives examples of its use in industry. The information has been derived from a Department of Trade and Industry/Engineering and Physical Sciences Research Council LINK project led by the University of Surrey; details of the project consortium are given on the back page. The approach integrates technical, performance, logistics, economic and legal constraints with environmental considerations and is applicable to all materials. It supports decisions on the environmental impacts of businesses products and services, while taking into account their wider business imperatives. This will help them maintain and increase their market share, with significant opportunities for long-term cost savings and environmental benefits. These arise through: less waste going to landfill FP272 FINAL RESULTS Factors influencing sustainable materials management reduced raw material use through cleaner design maximised product value from greater re-use and recycling compliance with existing and forthcoming legislation FUTURE PRACTICE: Tomorrow s technology and techniques for profitable environmental improvement

2 Background Most of the increasingly large amounts of plastics waste produced each year in western Europe ends up in landfill sites. The European Commission has introduced a number of initiatives to reduce this waste of resources and to tackle the environmental problems associated with landfilling. The packaging waste directive, the landfill directive and the draft directives relating to end-of-life vehicles, waste electrical and electronic equipment, and construction and demolition waste, all contain mandatory targets intended to boost recovery and recycling. Responsibility for achieving these targets rests with national governments and product manufacturers. The increasing emphasis on material recovery, re-use and recycling demands new tools to help industry make balanced decisions about the design and end-of-life management of their products. Chain Management of Polymers (CHAMP) is such a tool. The Project The methodology and software described here were the result of a project called the Chain Management of Polymers (CHAMP), run by the University of Surrey with seven industrial partners. The overall aim of the CHAMP project was to develop a methodology to allow engineers and designers to make informed choices about the selection of materials and processes for life-cycle product design (LCPD). CHAMP aims to minimise environmental impacts and to maximise the potential for material recovery, reuse and recycling while meeting technical, economic, legislative, social and other criteria. CHAMP can be applied to all materials, but most of the work done so far has focused on products containing plastics. Benefits of Using CHAMP CHAMP helps companies to compare the economic and environmental performance of alternative recycling and reprocessing options for polymer products and wastes. This provides a more sustainable approach to business. It helps identify opportunities for cost reduction, waste minimisation and environmental improvements such as: extended lifetime of raw materials; reduced impact of production. CHAMP Methodology The CHAMP methodology is based on life-cycle assessment (LCA) concepts. However, by tracking a material through a lifetime of use as the same or different products and by addressing technical, economic and other criteria as well as environmental considerations, it goes beyond the boundaries of conventional LCA. CHAMP models material flows through the series of processes which comprise the first and subsequent life-cycles of the polymer. All materials are tracked as they combine with other materials to form products. These products are used and eventually become waste. The methodology considers both polymer and non-polymer mass flows, takes full account of logistics and can also model delivery and collection options. CHAMP models operations such as moulding and identifies feasible options for material re-use and recycling based on the technical, economic, environmental, process and conditional criteria stipulated by the user. The modelling of multiple lifecycles, termed cascade of uses, is possible. Fig 1 highlights the potential routes different polymers can take during their lifetime. An example of a cascade of uses is a polythene container that is first recycled mechanically back into the same or another container and then recycled chemically back to its component hydrocarbons. These may then be used to produce a carrier bag, which is recycled mechanically before being disposed of by incineration with energy recovery. The CHAMP modelling produces a full assessment of the environmental impacts, economics and logistics. The optimum solutions for a particular material and set of constraints are determined using decision-support tools. The methodology is implemented using commercial 1 and in-house software incorporating a number of databases containing the information necessary to support the mathematical modelling and decision-support frameworks. Fig 1 Potential routes in the lifetime of a polymer Blending and forming Use Polymerisation Re-use Mechanical 1 There is other software available that performs some of the functions of CHAMP. recy Depolym Extraction an processing

3 Decision support The range of criteria to be satisfied can make it difficult for decision-makers to identify the best compromise solution for a given set of conditions and constraints. In addition, different decision-making environments (eg single decision-maker or multiple stakeholders) are best served by different decision-making techniques. CHAMP takes account of these complexities. CHAMP firstly provides environmental and economic assessments of all feasible options based on the system operation and constraints. Then the CHAMP methodology supports a number of techniques to help identify the optimum solution. This approach allows trade-offs between competing requirements. It also maximises environmental and social benefits against a demand for cost-effectiveness. Disposal Examples of the information gathered against each criterion are as follows: Technical criteria All materials are defined in terms of their application attributes such as physical and chemical properties, eg melting point and molecular weight, and other factors including geographical location. These can change during their lifetime and are used to: select materials for their initial and subsequent uses; identify those applications satisfying a material s properties. Economic criteria The CHAMP methodology: models all internal costs (eg materials, energy and labour); compares the total cost of alternative systems. Environmental criteria The environmental impacts from all stages of production (eg mining, processing, transportation and waste management) are determined by the CHAMP methodology using conventional methods, including: direct and indirect impacts of products; resource use; emissions to air, water and land. Processing operations A material s characteristics change as it passes through processes such as extrusion, injection moulding or granulation. CHAMP uses functional relationships to model the precise way in which this happens, including changes in: technical performance; environmental impacts; costs incurred. ng c erisation Chemical pyrolysis and recycling Energy recovery Conditional criteria Like a quality control system, CHAMP puts materials through pre- and postoperation tests to check that the operation or manufacturing process is acceptable. Criteria can be set for each operation to filter material characteristics and to dictate possible routes for processing, recovery, re-use and recycling. These criteria include: material properties and performance; processing requirements and constraints; supply chain and stakeholder characteristics; relevant legislation and financial instruments; material additives and degradation constraints; d Resource commercial and social factors.

4 The Methodology in Practice Material Selection for Data Cable Recycling CHAMP has been used to compare the potential for recovery and recycling of two types of data cable manufactured by Brand-Rex Ltd. The cables consist of four pairs of insulated copper conductors held in a sheath made of either polyvinyl chloride (PVC) or low smoke and fume (LSF). The technical performance, environmental impact and economics of both cable systems were considered using the CHAMP methodology. On the basis of current thinking, PVC offers the best potential for recycling. The knowledge obtained from this project will provide us with a full understanding of the environmental performance of one of our biggest selling products and help us to explore the environmental and cost savings of future design changes. Brand-Rex Ltd Designing Fibre Optic Cables for Recycling The design of one of the fibre optic cables produced by Corning Cable Systems Ltd currently uses at least ten components. This makes it both technically and economically difficult to re-use or recycle the cable. Corning Cable Systems has worked with the CHAMP team to change the design of this cable so as to make it easier to dismantle and recycle. The CHAMP methodology has been used to compare the new design with the original and to ensure that technical, economic and environmental criteria are met. Options for the recovery and re-use of materials from the newly designed cable are being identified and the overall economics assessed. Comparing Recovery Options for Plastics Packaging Introduction of the packaging waste regulations in 1997 placed greater responsibility on producers to recover and recycle their own products after use. Biffa Waste Services Ltd is using CHAMP to identify trade-offs on a regional and national scale between the competing collection and disposal options of recovery, waste-to-energy and landfill. CHAMP is being used to compare the environmental and economic impacts of different recovery options for plastics packaging based on different volume and distance variables. The implications of different collection, transportation and separation systems compared to current disposal options will also be assessed. These options include: bulk pick-up; dedicated and mixed kerbside collection; incineration with energy recovery; pyrolysis; polymer recycling; and landfill. The project, which uses data from mass balance studies from the Isle of Wight and other areas of the UK, is focusing on material flows in domestic, commercial and industrial waste for the commonest types of plastics packaging. Information is the key to sound policies and decision-making in all organisations. The approach shown here helps interpret that information and thus manage the risks and change in all our lives. Biffa Waste Services Ltd Recycling Electronic Equipment The polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) panels used for the external cases of photocopiers and other electronic equipment can be re-used in two ways. The first involves cleaning, repairing and painting the panel for re-use on the same or a similar type of machine. The second involves pulverising the panel into granules and moulding a new panel using a mixture of the granules with virgin material. Both options have their benefits and limitations. Xerox and Mann (UK) are using the CHAMP methodology to compare the two options to find solutions that maintain technical requirements while minimising environmental and economic burdens.

5 Recycling Laminated Glass Windscreens Unlike glass, the polyvinyl butyral (PVB) interlayer used by Pilkington plc in its laminated car windscreens is currently not recycled but is landfilled. Under the draft EC directive on end-of-life vehicles, this option may not be allowed. The draft directive also imposes high recovery and re-use targets for the materials found in scrap cars. Possible recycling cascade for polymer interlayers Windscreen interlayer: 3-year lifetime Flexible coverings such as soft cable sheaths or synthetic leather: 15-year lifetime Flooring: 20-year lifetime Polymer to landfill Pilkington has been working with the CHAMP team to assess alternative commercially available polymer interlayers that could be recycled. Having checked the technical performance of polyvinyl chloride (PVC), ethylene vinyl acetate (EVA) and polyurethane (PU) against product specifications, the relative merits of using PVC, EVA, PU and PVB were determined using the CHAMP methodology. Disposal to landfill was used as the ultimate end-of-life destination. The environmental impacts of the alternative polymer interlayers were comparable with the existing PVB system, although the magnitude of different types of impact varied. Total polymer life: 38 years The team then investigated the possibility of recycling the different polymers. No applications were found for PVB, but several options were identified for the other polymers where the environmental impact and costs of using the recycled material were significantly lower than if virgin material was used. Environmental considerations are becoming ever more important to our decisions on materials selection and use. The project will allow us to make objective comparisons of alternative systems and improve our ability to supply future markets. Pilkington plc The Logistics of Toner Bottle Recovery High density polyethylene (HDPE) toner bottles supplied by Xerox are currently discarded as commercial waste. CHAMP has been used to investigate the viability of collecting post-consumer toner bottles for direct re-use or material recovery. This would not only have cost benefits for Xerox, but would enhance the Company s corporate commitment to the environment. The study involved tracking the toner bottles as they passed from cradle to grave, ie from polymer production to disposal in an incinerator or a landfill. Four recovery, re-use and recycling schemes were used to explore various mechanisms for collecting the used toner bottles for subsequent re-use, either directly or in another application. Customer locations, consumption data and transportation information (vehicle types, availability, cost, etc) supplied by Xerox were used in the study. CHAMP has allowed Xerox to identify ways to simulate the local recovery and recycling of a high-grade material. This should make it easier to provide consumers with a disposal route for their empty toner bottles with both environmental benefits and low logistics costs. The approach will provide us with a more systematic and rational decision-making tool for materials selection, parts design and even supply chain processes, and enable us to implement product take-back and reprocessing more efficiently and effectively. Xerox

6 Future Development The CHAMP project has developed a powerful methodology for product design and material/process selection that will lead to optimum recovery and recycling options for any product or material waste stream. In the next stage of development, the methodology will be applied to more industrial examples and to more complex situations. The focus will be on materials management, product design, process modelling, logistical modelling and operational options for recyclate. This phase will also involve the development of extended databases of material properties and process parameters to achieve improved material cascading. Integration of the CHAMP framework with existing environmental and business systems will also be investigated. Companies interested in joining the consortium should contact the Polymer Research Centre, University of Surrey (details below). For more information about the project, visit the CHAMP web site at For the latest ETBPP publications about life-cycle assessment and cleaner design, contact the Environment and Energy Helpline on freephone Life-cycle Assessment - An Introduction for Industry (ET257) describes the main elements of LCA and explains how this decision-aiding tool can help companies in the manufacturing and service sectors to achieve cost savings and environmental benefits. Free copies of this publication are available through the Environment and Energy Helpline on freephone CONSORTIUM MEMBERS Project Leader: University of Surrey, Guildford, Surrey GU2 7XH Tel: Fax: prc@surrey.ac.uk Collaborating Departments: Polymer Research Centre (Project Manager) Centre for Environmental Strategy Department of Chemical and Process Engineering Project Partners: Biffa Waste Services Ltd Brand-Rex Ltd Corning Cable Systems Ltd European Vinyls Corporation (UK) Ltd Mann Organisation Pilkington plc Xerox Department of Trade and Industry (DTI LINK Programme) Engineering and Physical Sciences Research Council (EPSRC) Environmental Technology Best Practice Programme (ETBPP) FOR MORE INFORMATION ABOUT THE ENVIRONMENTAL TECHNOLOGY BEST PRACTICE PROGRAMME AND HOW ITS FREE SERVICES CAN HELP YOU, PLEASE PHONE THE ENVIRONMENT AND ENERGY HELPLINE ON world wide web: address: etbppenvhelp@aeat.co.uk THE ENVIRONMENTAL TECHNOLOGY BEST PRACTICE PROGRAMME IS A GOVERNMENT PROGRAMME MANAGED BY AEA TECHNOLOGY ENVIRONMENT AND NPL MANAGEMENT LTD Crown copyright. First printed September This material may be freely reproduced in its original form except for sale or advertising purposes. Printed on paper containing a minimum of 75% post-consumer waste.