Multimodal network design for sustainable household plastic recycling

Purpose - This research studies a plastic recycling system from a reverse logistics angle and investigates the potential benefits of a multimodality strategy to the network design of plastic recycling. This research aims to quantify the impact of multimodality on the network, to provide decision support for the design of more sustainable plastic recycling networks in the future. Design/methodology/approach - A MILP model is developed to assess different plastic waste collection, treatment and transportation scenarios. Comprehensive costs of the network are considered, including emission costs. A baseline scenario represents the optimized current situation while other scenarios allow multimodality options (barge and train) to be applied. Findings - Results show that transportation cost contributes to about 7 percent of the total cost and multimodality can bring a reduction of almost 20 percent in transportation costs (CO2-eq emissions included). In our illustrative case with two plastic separation methods, the post-separation channel benefits more from a multimodality strategy than the source-separation channel. This relates to the locations and availability of intermediate facilities and the quantity of waste transported on each route. Originality/value - This study applies a reverse logistics network model to design a plastic recycling network with special structures and incorporates a multimodality strategy to improve sustainability. Emission costs (carbon emission equivalents times carbon tax) are added to the total cost of the network to be optimized.