Why is Recycling of Postconsumer Plastics so Challenging?

TLDR

The widespread use of plastics, driven by low cost and desirable properties, challenges waste management, and despite long‑standing recycling programs, much plastic still ends in landfills, prompting a need for innovative strategies to economically convert waste into valuable products for circular use. This review aims to describe the technical and economic hurdles of postconsumer plastic recycling and to overview emerging strategies—new polymer design, new recycling processes, and chemical transformations—to recover waste into value‑added products. The review discusses specific challenges such as waste sorting and separation, product variability including additives, and the high efficiency/low cost of petrochemical virgin polymer production, particularly polyolefins. Although many technical strategies exist for mechanical and chemical recycling, commercial success is limited by performance variability or high costs, and successful capture will depend on economic incentives and government regulations.

Abstract

The ubiquitous use of plastics has been driven by their combination of low cost and properties, but these attributes directly challenge waste management schemes for plastic recycling. Some postconsumer recycling programs are now nearly 50 years old, but a significant fraction of plastics still finds landfills or other dumping strategies at their end of life. With the growing concern regarding plastic waste, especially ocean plastics, there is a need for innovation and alternative strategies for the economic translation of plastic waste to valued product(s) that will promote their efficient circular utilization. This review first describes the technical and economic hurdles associated with the recycling of postconsumer plastics, but then it focuses on providing an overview of emergent strategies to recover plastic waste through new polymer design, new recycling processes, and chemical transformations to value-added products. Specific challenges discussed include plastic waste sorting and separations, product variability including additives, and the high efficiency/low cost in which the existing petrochemical industry can produce virgin polymers, in particular polyolefins. Although a wide variety of technical strategies have been demonstrated for recycling of plastics through both mechanical and chemical means, the commercial success of these different strategies is generally limited by either performance, including large variance in key metrics, or economics where the products can match the performance of virgin materials but the recycling process is expensive. Successful capture of postconsumer plastic waste through recycling likely will depend on economic incentives and government regulations.