The most widely reported activity using end-of-life composites that would otherwise be disposed of in landfills is the use of ground up wind turbine blades as an input to cement manufacturing, but this may not be the best model for the industry as a whole. Blades are taken out of service at predictable times and places, while the disposal of most other types of composite products is widely dispersed in time and location and the collection of significant quantities of material would be much more complicated, expensive and environmentally impactful.
Further, to be considered fully sustainable, the output of a recycling process should be used back in the process that made the original product, reducing the industry’s use of high-value virgin materials. Finally, one study concluded that the emission of climate warming gases from the use of out-of-service blades as an input to cement manufacturing could exceed the amount emitted if the blades were directly landfilled.
To achieve overarching results, the industry should continue to support development of economically and environmentally sustainable collection and recycling technologies that provide high-value products. Even though such technologies may not be viable in the near term, eventually all industries will be expected to substantially reduce their use of non-renewable resources.
In the meantime, there isn’t a shortage of landfill space in most of the United States. Composite materials are inert and will not degrade in a landfill and release pollutants into the water or air. The environmental and social impacts of disposing of this material in local landfills is likely less than transporting the material significant distances to where it will be processed and used.
It is possible that government action will change the economics of recycling composites. Motivated by the accumulation of discarded plastic in the ocean and the dumping of plastic waste in less developed countries, some members of Congress are considering taxes on virgin resin or other incentives for increased recycling, and the same motivation is behind efforts to craft a global plastics treaty requiring end-of-life recycling of all polymers.
As discussed earlier, composite products typically provide decades of significant environmental and social benefits during their use. Increasing public awareness of the use-phase sustainability benefits of composites may be as important as recycling for escaping taxes, regulations or other government policies aimed at reducing the mishandling of discarded single-use, non-durable plastic products like packaging.
To summarize, the composites industry needs to respond to the needs of its customers by assessing and then acting to reduce the climate impacts associated with the manufacture of composite products and raw materials. And the industry can reduce the risk of recycling mandates, taxes or other regulatory requirements, as well as support increased use of its products, by increasing public awareness of the use-phase sustainability benefits of composites. Looking to the future, the industry should continue to support development of recycling technologies and logistics that provide high-value products and are economically and environmentally sustainable.