Carpet Recycling: Determining the Reverse Production System Design

Roughly 4 billion pounds of carpet are disposed of in the United States each year. This carpet is composed of a significant fraction of nylon, polypropylene, and polyester fiber. A key limiting factor to recycling is effective design and development of the reverse production system to collect and reprocess this large volume of valuable material. A reverse production system is composed of material and chemical recycling functional elements interconnected by transportation steps. In this article, we develop a mixed-integer programming model to support decision-making in reverse production system design. To illustrate its use and applicability, we apply the model to a representative U.S. carpet recycling industrial case study. The overall economic feasibility of recycling is strongly dependent on the volumes that can be expected from investments in collection infrastructure. The geographic location of processing centers influences the network economics, and the subdivision of recycling tasks to avoid the shipment of low value material is proposed as an effective strategy for carpet recycling.