Upcycling Ocean-based Plastics for Sustainable Feedstock Supply Chain

Plastics are ubiquitous in modern life. Global production of plastics (polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinylchloride (PVC), and others) has reached about 400 million tons annually. Total plastics production has increased by 36% in the past decade and is estimated to grow to 700 million tons in 2030. The National Center for Ecological Analysis and Synthesis (NSEAS) estimated that over 10% of used plastics ends up in the ocean and the cumulative effect of this is that nearly 100 grocery bags full of plastics would be filled in every foot of coastline in the world by 2025. Ocean vortices form “garbage patches” or “stomach-size colorful plastic piles” of disposed plastics and attracts seabirds. Slow photo-degradation of plastics forms microscopic pieces, creating waterborne pollutants and leaching toxins, and causing health risks to ocean life and humans through the food chain. Often the gravity of this environmental challenge is expressed as “nearly every seabird may be eating plastic by 2050”. The challenges of plastics and increasing feedstock demand can be simultaneously addressed by proper characterization of ocean plastics and their selective upcycling into chemicals and fuels. Currently a small fraction of PET and HDPE plastics, sorted out from mixed plastics using optical machinery, are recycled through mechanical processing. The mechanical recycling technology causes significant loss in the properties (lower ductility, diminish molecular weight and mechanical strength) of plastics and the recycled materials are used for low value applications, which is often referred to as ‘carbon downcycling’. RiKarbon, Inc. is developing enabling technologies to properly characterize ocean plastics compositions and contaminates to selectively upcycle into functional monomers to enable production of the same plastics again and again with similar value and material properties. It will bring significant economic, societal and educational benefits: (1) upcycle carbon from waste plastics, (b) develop waste plastics as a sustainable feedstock for US and global chemical enterprises, (c) produce higher value monomers (e.g. ~$1300/ton) for new renewable plastics, (d) promote waste plastics collection at source, (e) mitigate the environmental and ocean water challenges of plastics and global carbon emissions, (f) improve future energy security, and (g) promote a circular carbon economy. RiKarbon is implementing a holistic approach for upcycling the entire waste plastics systematically into their constituent functional monomers. In this Phase I project, RiKarbon will (a) characterize ocean plastics compositions, contaminates, and structural properties, (b) develop a well-defined feedstock for upcycling, (c) study the effect of ocean water contaminates on selective upcycling of PET plastic fraction via CO bond cleavage in RiKarbon’s one-step and energy efficient process, (d) compare depolymerization productivity of real ocean PET plastic with simulated PET plastic composition to assess any advantages for ocean plastics caused by property changes in ocean by weathering and biofouling in the presence of high salt and sunlight, and (e) techno-economic and life-cycle assessment.