(243f) Upcycling Polystyrene Waste to Adipic Acid through Combined Chemical and Biological Reactions

Known for its durable, lightweight, and insulating properties, polystyrene (PS) is widely used in multiple applications, including in packaging and construction materials. However, 91% of PS went to landfills in the US in 2019 alone. Thus, developing approaches that efficiently convert discarded PS into value-added products is urgent to limit the environmental burden. This presentation will focus on the conversion of post-consumer PS to high-volume chemicals through autoxidation catalysis, bioprocessing, and hydrogenation. In the PS deconstruction process, PS is converted into benzoic acid with a 92 mol% yield by modifying the Amoco process. The results indicate that a high yield of benzoic acid can be achieved by inhibiting the hydroxylation of the PS chain and the decomposition of benzoic acid. The recovered benzoic acid is then subjected to bioprocessing, resulting in cis,cis-muconic acid in 97 mol% yield. Subsequently, the hydrogenation of cis,cis-muconic acid leads to the production of adipic acid with a yield of more than 99 mol%. A techno-economic analysis of the PS autoxidation process showed an approximately 20% reduction in the minimum selling price. Furthermore, the modified PS deconstruction process reduces GHG emissions by 17% compared to the traditional benzoic acid process, due to lower consumption of materials and utilities.