Design of the Transition for Sustainable Plastic Waste Management under Carbon Policies in the United States

The growing environmental and economic challenges posed by plastic waste demand innovative and strategic solutions. This study presents a decision-making framework using mathematical programming to determine the technologies, their location, and the transportation method (electric or with conventional trucks) under different scenarios: maximizing profit, maximizing decarbonization, maximizing plastic circularity, and maximizing profit under carbon tax and carbon cap policies. Results suggest upcycling by pyrolysis for maximizing profit; hydrocracking and mechanical recycling for maximizing the decarbonization; hydrocracking, pyrolysis, and mechanical recycling for carbon tax and carbon cap schemes; and mechanical recycling combined with chemical recycling for maximizing circularity. These results highlight the challenges of simultaneously maximizing circularity and meeting the 2050 decarbonization targets proposed by the Paris agreement as chemical recycling involves pyrolysis, a highly energy intensive technology. The assessment of the policies shows that current carbon taxes are not sufficient for achieving those decarbonization targets. To address this, either higher taxes or a carbon cap policy mechanism are needed with four recommended technologies: upcycling based on pyrolysis and hydrocracking, chemical recycling, and mechanical recycling.