Portal de Periódicos da CAPES

Robust reverse production system design for carpet recycling

2004; Taylor & Francis; Volume: 36; Issue: 8 Linguagem: Inglês

10.1080/07408170490458580

1545-8830

Matthew J. Realff, Jane C. Ammons, D. J. Newton,

Environmental Impact and Sustainability

Abstract It is estimated that complete carpet recycling would avoid an estimated US annual landfill cost of $65 million, while simultaneously recovering lost material valued at $750 million. Designing an adequate reverse production system is critical to the economic viability of recovering this lost value. We develop a robust-mixed-integer linear programming model to support decision-making for reverse production infrastructure design. Our robust model seeks solutions close to the mathematically optimal solutions for a set of alternative scenarios identified by a decision-maker. To demonstrate the approach, a representative industrial case study is given for a large-scale carpet recycling problem. A robust solution is found that appraises the impact of two major sources of uncertainty, volumes of carpet collected and price of a key recycled material. Acknowledgements and disclaimer This research has been partially supported by the National Science Foundation under grant 9800198 and the Consortium for Competitiveness in Apparel, Carpet, Apparel and Textile Industries (CCACTI) of the State of Georgia. The authors are grateful for the generous interaction and guidance provided from many industry experts, especially those from Mark Ryan of DuPont and Mike Costello of Honeywell International. We value the input from Georgia Tech Ph.D. student Selin Cerav and M.S. student Mohit Madnani. We also gratefully acknowledge the valuable suggestions and clarifications provided by the editor and anonymous reviewers. It should not be assumed that the results in the paper's case studies can be used to judge the economics of current carpet recycling efforts. Although the data is representative of general trends and qualitative differences, none of the numbers or networks described can be interpreted as the operational reality of any existing company or system. Some of the results reported here have been presented earlier at the Third International Seminar on Reuse, Eindhoven University of Technology, Eindhoven, The Netherlands. Notes ∗Annualized costs are based on taking the total capital costs and depreciating them over 7 years to generate an annualized equivalent cost. ∗The number after a process indicates the process capacity in millions of pounds annually.