MOSCOW (MRC) -- To determine the best way to recycle and reuse plastic, researchers at the U.S. Department of Energy’s (DOE) National Renewable Energy Laboratory (NREL) examined the benefits and trade-offs of current and emerging technologies for recycling, said Recyclingtoday.
The paper is called “Technical, economic and environmental comparison of closed-loop recycling technologies for common plastics,” and provides a comparison of various technologies for closed-loop recycling. This allows for the reuse of plastic through mechanical or chemical processing, eliminating the need for fossil-fuel-derived virgin materials. They considered technical metrics like material quality and retention and environmental metrics, including energy use and greenhouse gas emissions.
“We know cost is one of the primary ... drivers for recycling for companies wanting to invest in it,” says Taylor Uekert, the lead author. “I think it’s just so important to remember that there are other things that are equally important for our life on this planet and we need to be considering those environmental impacts as well."
Her co-authors, all from NREL, are Avantika Singh, Jason DesVeaux, Tapajyoti Ghosh, Arpit Bhatt, Geetanjali Yadav, Shaik Afzal, Julien Walzberg, Katrina Knauer, Scott Nicholson, Gregg Beckham and Alberta Carpenter.
The article outlines how effectively closed-loop recycling technologies would work on polyethylene terephthalate (PET) and three types of polyolefins: high-density polyethylene (HDPE), low-density polyethylene (LDPE), and polypropylene (PP). The recycling rates of these polymers varied in the United States during 2019, from 2 percent for LDPE to 15 percent for PET bottles and containers.
Two closed-loop recycling methods are available for HDPE, LDPE, and PP plastics: mechanical, in which the plastic is grounded, melted and made into something new. There also is a solvent-based dissolution, which removes impurities so that the plastic is of suitable quality for reuse. Those same processes can be used on PET in addition to enzymatic hydrolysis, glycolysis and methanolysis.
More than 400 million metric tons of plastic waste are generated globally annually. Current recycling strategies can capture a fraction of these plastics, but there is a lack of consistent data on the capabilities and impacts of these processes. The NREL study quantitatively characterized the performance of plastic recycling technologies—including factors that are usually only discussed qualitatively, like contamination tolerance—and established a methodology for comparing new recycling processes as they emerge.
We remind, PureCycle Technologies Inc. and the Port of Antwerp-Bruges have announced that PureCycle will build its first polypropylene (PP) recycling facility in Europe at the port’s NextGen District in Belgium. The Orlando, Florida-based company says it expects the new plant to have an annual capacity of 59,000 metric tons, with opportunities to expand operations down the road since the 34-acre plot can support up to four processing lines, increasing total capacity to around 240,000 metric tons per year.