Historically, plastic recycling is associated with mechanical recycling — this basic method is a well-known, mainstream method of dealing with plastic waste. In general, it involves gathering the product, sorting, washing for decontamination, shredding and melting. The order may vary, but the result is similar.
The downside to this approach is the level of purity. To be used effectively in a recycled polyester (rPET) fiber product, the recycled material often must be blended with virgin polyester. Keep in mind that the melt product, usually in the form of pellets, is polymerized polyester, not the monomers or raw materials that form the polymer chains that are polyester.
Eastman Develops Advanced Circular Recycling Technologies
There are seven types of plastic resins produced and identified with Resin Identification Codes (RIC) 1 through 7. Mechanical recycling only processes RIC 1 (PETE) and RIC 2 (HDPE). Eastman’s molecular recycling doesn’t impose those limitations — the company has developed innovation technologies that give it the capability to recycle almost any plastic waste. Eastman’s molecular recycling technologies complement mechanical recycling to reimagine recycling as the world knows it, creating a future where almost all plastic products, even at end of life, are still regarded as valuable and do not become waste.
Eastman’s molecular recycling can process RIC 1-7 with the exception of RIC 3 — polyvinyl chloride.
Eastman employs two molecular recycling solutions: carbon renewal technology (CRT) and polyester renewal technology (PRT).
Polyester Renewal Technology (PRT)
Eastman’s PRT is a form of molecular recycling that enables the company to process a wide range of polyester plastic waste, which includes materials such as soft drink bottles, carpet and textiles, diverting these materials from landfills or incineration. This waste stream goes beyond clear, single-use water bottles to include products such as colored plastic bottles and food containers, and polyester carpet.
PRT unzips polyesters and converts them into their basic monomers to create new materials. The molecules produced are indistinguishable from materials made with virgin or non-recycled content. This process, also known as depolymerization, allows Eastman to recycle polyester waste over and over again without degradation over time and reduces greenhouse gas emissions by 20 to 30 percent compared to processes using fossil fuels.
Eastman currently has a glycolysis-based PRT process operational in Kingsport, Tenn. with a new facility using the process of methanolysis that will be mechanically completed in 2022.
Molecular Recycling Facility Will Be One Of The World’s Largest
For almost two years, Eastman has asserted its commitment to accelerate the circular economy, and on January 29, that commitment increased by orders of magnitude. That’s the day Eastman Board Chair and CEO Mark Costa announced the company’s significant investment in the new, aforementioned molecular recycling facility, in Kingsport. The facility will provide intermediates that will enable the production of between 150 and 200 kilo metric tons (KMTs) of polymer production, depending on product mix. The feedstock for the facility will be hard-to-recycle polyester waste.
In announcing the new facility — with construction slated to begin in March — Costa said this material-to-material solution will not only reduce the company’s use of fossil feedstocks but also reduce its greenhouse gas emissions by 20 to 30 percent relative to processes that use fossil feedstocks.
Eastman set ambitious sustainability goals in December 2020. Those commitments include a goal of recycling more than 250 million pounds of plastic waste annually by 2025 and more than 500 million pounds of plastic waste annually by 2030. Eastman also set a goal of achieving carbon neutrality by 2050.
“With the growing demand for products made with recycled content and the urgent need to address the global plastic waste crisis, now is the time for Eastman to take this step,” Costa said.
Carbon Renewal Technology (CRT)
Eastman commercialized CRT first among its technologies because the company was able to convert existing assets to recycle complex plastics on the molecular level. By leveraging an existing asset, the company was able to go from announcing its plans for CRT to commercialization within nine months.
Eastman uses PRT and CRT to recycle different kinds of complex plastics, and through different processes.
PRT is specifically applicable to recycling polyester, and CRT can be used to recycle almost any kind of plastic. The technologies each provide materials with certified recycled content for different end-market products: PRT materials are used in Eastman’s polyester stream for products such as Tritan™ Renew; and CRT materials are used for products in its acetyls stream such as its Naia™ Renew cellulosic fiber. The two technologies share an important attribute in that both produce new materials from plastic waste that is indistinguishable from materials made from traditional processes.