Non-household end-use plastics: the ‘forgotten’ plastics for the circular economy

Limited utilization options for secondary plastics may restrict their circularity

Plastic recycling can provide environmental benefits by avoiding the detrimental impacts of alternative disposal pathways and enabling the substitution of primary materials. However, most studies aiming at increasing recycling rates have not investigated how the resulting secondary materials can be utilized in product manufacturing. This study assesses the future substitution potential of primary with secondary plastics, building on a material flow system of 11 plastic types in 54 product subsegments in Switzerland in 2017 with a recycling rate of 9%. In a prospective material flow analysis of a scenario for 2025, the collection rate of the plastic fractions collected in 2017 is increased to 80%. The secondary material flows are allocated to suitable uptaking product subsegments using a linear optimization. The maximum share of secondary materials utilizable in each product subsegment is estimated, whereby three sub-scenarios involving high, moderate and low allowed secondary material shares are modelled. Depending on plastic type and scenario, 21% to 100% of the secondary material gained can substitute for primary material, covering 11% to 17% of the total material demand. While the overall recycling rate could reach 23%, taking into account only the uptaken secondary materials a true recycling rate of only 17% results in the moderate applicability sub-scenario. Based on these results, the secondary material uptake can be said to constitute a limiting factor for increased future recycling. Therefore, thorough consideration of the possible secondary material application is a prerequisite for designing and assessing future recycling systems or for setting recycling rate targets.

The Critical Role of Process Analysis in Chemical Recycling and Upcycling of Waste Plastics

There is an urgent need for new technologies to enable circularity for synthetic polymers, spurred by the accumulation of waste plastics in landfills and the environment and the contributions of plastics manufacturing to climate change. Chemical recycling is a promising means to convert waste plastics into molecular intermediates that can be remanufactured into new products. Given the growing interest in the development of new chemical recycling approaches, it is critical to evaluate the economics, energy use, greenhouse gas emissions, and other life cycle inventory metrics for emerging processes, relative to the incumbent, linear manufacturing practices employed today. Here we offer specific definitions for classes of chemical recycling and upcycling and describe general process concepts for the chemical recycling of mixed plastics waste. We present a framework for techno-economic analysis and life cycle assessment for both closed- and open-loop chemical recycling. Rigorous application of these process analysis tools will be required to enable impactful solutions for the plastics waste problem. Expected final online publication date for the Annual Review of Chemical and Biomolecular Engineering, Volume 13 is October 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Impact of China’s National Sword Policy on the U.S. Landfill and Plastics Recycling Industry

This paper analyzes the impacts of China’s Green Fence and National Sword Programs, under which strict contamination limits were imposed on recyclable materials, besides prohibiting imports of low quality recyclables. Specifically, this study investigates the impacts of this policy on landfills, and the risks to the U.S. plastics secondary materials market and material recovery facilities (MRFs). A hierarchical regression analysis reveals the significant impacts of China’s Green Fence and National Sword polices on the amount landfilled plastic. Controlling for oil prices, producer price index (PPI), and amount of plastic scrap exported, our findings show that the Green Fence had no statistically significant impact on the amount of plastic landfilled in the U.S. However, the quantity of plastic landfilled in the U.S. increased by 23.2% following the implementation of National Sword. Furthermore, analysis of the annual reports submitted by registered MRFs in New York (NY) state reveals that the total amount of plastic recovered by them has decreased. We suggest that demand creation and investments that improve the quality of bales are needed to help solve this economic dilemma.