Logistics of carpet recycling in the U.S.: designing the recycling network

Abstract

Transportation of post-consumer carpet from collection points to recycling facilities and then to the end-users of the recycled materials contributes significantly to the final costs of recycled materials. In this article, several alternative network designs for the U.S. carpet recycling systems are developed and compared in terms of network costs. In two scenarios, these networks include layers of local collection centers, recycling plants, and markets for recycled materials. In the third scenario, a layer of regional collection centers is added before the recycling plants to aggregate carpet for more efficient sorting and transportation. To find the optimal number and locations of recycling plants and regional collection centers as well as the optimal flows among network facilities, a hierarchical facility location model is formulated that can be used for the different network configurations considered. To solve large-scale instances of the problem, a heuristic method based on the alternative location-allocation procedure is developed, and a computational study is conducted to assess its performance. The results of the study can be used by organizations involved in carpet recycling in the U.S. to establish reverse networks. In addition, the optimization model and the solution heuristic can be used for similar problems in forward or reverse logistics.