برنامه ریزی عملیات بازیافت برای مدیریت پایان عمر ضایعات وسایل برقی و الکترونیکی

The ever-increasing amount of waste from electrical and electronic equipment (WEEE) has become a common problem due to the significant environmental and health impacts associated with inappropriate End-of-Life (EoL) management. The current ad hoc applications of WEEE recycling are often based on limited knowledge and cannot cope with the complex range of materials and products in such waste. A knowledge-based approach has been utilised to investigate the realisation of a recycling process planner which aims to determine the most suitable EoL options for WEEE. A number of case studies have been used to show that a 20–30% improvement on economical and environmental performance could be achieved through adoption of such a systematic approach to recycling process planning.

Technological innovation and shorter product life cycles of electrical and electronic equipment coupled with their rapidly growing applications have resulted in generation of enormous amount of WEEE which is expected to increase further by 3–5% per annum [1]. This has resulted in the introduction of Producer Responsibility (PR) directives for WEEE in the EU, in which manufacturers and importers are made responsible for the take back and recycling of their products [2]. The main objective of such PR directive was to involve the manufacturer in the EoL management of their product. However, the current implementation of this directive has failed to achieve its objective, as many manufacturers have opted to conform to the WEEE directive by moving away from actively fulfilling the requirements themselves, in favour of subcontracting the recovery and recycling of their products through a number of producer compliance schemes. Hence, the burden of WEEE recycling has been placed on an isolated recovery industry with a superficial understanding of the products they are recovering. These recovery facilities are often developed on an ad hoc basis and mainly due to the hidden economic value within the used products. The recovery treatments and recycling activities in these facilities are mainly based on the limited capabilities and available resources without any detailed assessment of the environmental benefits of the recycling activities. However, such recycling facilities are now faced with the challenge to improve their recycling activities and recover a larger proportion of components and materials at a reasonable cost and at the same time to meet the ever-increasing number of legislative requirements [3] and [4]. The research reported in this paper aims to take advantage of the benefits provided by a knowledge-based process planning approach in manufacturing applications and apply a similar principle to increase the efficiency of recycling activities. The proposed recycling process planner (RPP) utilises a variant approach [5], in which the similarities in the features and attributes among a family of products/parts are used to select and modify a predefined ‘standard process plan’ to generate a bespoke recycling process plan for an electrical/electronic product. A number of case studies have also been presented to highlight the significant improvements in the ecological and economical performances of the WEEE recycling that can be achieved through adoption of the RPP.

The proposed recycling process planning approach aims to take advantage of the significant benefits provided by process planning in manufacturing applications and apply a similar principle to increase the efficiency of recycling activities. The RPP framework determines the most suitable trade-offs between ecological and economical variables and includes simultaneous consideration of the macro- and micro-level EoL planning to identify an appropriate sequence of eco-efficient recycling processes for individual products in WEEE. The reduction of the hidden value in electrical and electronic products is impacting the economics of WEEE recycling. This clearly highlights a need on one hand to reduce the cost of recycling, most probably through increased automation, and on the other hand the need for better value recovery from WEEE through increase rate and quality of materials recovered. The current recycling practices of meeting the recovery and recycling obligations at a marginal cost is very much dependant on the high scrap metal prices. Any change in the scrap metal price or increase in recovery and recycling targets can have severe impact on the whole economics of WEEE recovery and recycling, and hence it is argued that the adoption of proposed RPP approach to planning of recycling activities for WEEE could be of paramount importance in ensuring the long term sustainability of WEEE recycling. Finally, it is envisaged that CARPP would enable manufactures as well as recyclers to determine the EoL cost associated with particular product upfront leading to better cost negotiations with their product recovery agents which would in turn encourage manufacturers to improve the design of their products with EoL considerations.