Mechanical recycling is the main way PET is recycled, but methods using depolymerization and other processes are also being developed around the world.

Several projects are underway around the world to deal with PET packaging and fiber waste that is not suitable for mechanical recycling in different ways.

 

Molded plastics and textiles using specialized enzymatically depolymerized PET

French company Carbios is developing a recycling process that uses specialized enzymes to depolymerize PET molded plastic and textiles. The Carbios demonstration plant, launched in central France in September 2021, is now fully operational and company chief executive Emmanuel Ladent said the results were “very good”. Carbios is in talks with several major potential customers, including not only PET producers, but also waste management companies and possibly even brand owners.

 

The plant operates in batches and can process up to 2,000kg of waste at a time, with each process lasting 10 to 20 hours. The recovery rate of 97% can be achieved after running for nearly 20 hours. “We are very confident in the technology, but we will continue to optimize the process and handle the enzymes. Our goal is close to 100% recovery.” Radente said.

 

In February last year, the company announced it would partner with Indorama Ventures to build its first prototype plant, with a capacity of 50,000 tonnes, in Lan-la-Ville, France, near the border with Belgium and Luxembourg. Indorama already has a polymer production facility nearby. Radiate also said that the area has a high volume of waste, so supply logistics should be favorable. Currently negotiating cooperation with potential raw material suppliers.

A few months ago, Carbios formed a consortium with multiple brands in the packaging industry chain, including L’Oreal, Nestle, Pepsi and other plastic products. In early July 2022, the company announced the establishment of a textile industry chain alliance involving brands such as Patagonia, On, Puma and Salomon to develop textiles that can improve product reliability. Recycling and circular solutions.

 

A key element of the two-year agreement is to accelerate the introduction of Carbios’ bio-recycling technology to the textile industry. Carbios and the four companies will also study how products are recycled, develop solutions for recycling used polyester products, including sorting and dismantling technologies and collect data on fiber-to-fiber recycling and recycling models.

 

“We have done a lot of tests, although not yet at an industrial level. We are working on the steps of waste pre-treatment,” Radente said. “We are very confident that polyester textile recycling will be an important milestone for Carbios.”

 

The beauty of the process, Radente said, is that it tolerates contaminants. “It means, for example, that we can handle multi-layer pallets.” The factory can recycle PET bottle fragments, but this option is not practical given the high cost of recycling. In Europe, about 8 to 9 percent of PET post-consumer waste is food trays, which are currently either landfilled or incinerated, making it less expensive to buy the raw material, Radente said.

 

Carbios’ life cycle assessment shows that the process has 46% lower CO2 emissions than using single-use virgin PET bottles. The company will further study how it compares to other PET depolymerization processes and mechanical recycling.

Last August, Carbios joined the four-year White-Cycle project, which aims to adopt and deploy circular solutions to recycle more than 2 million tonnes of PET per year by 2030. The consortium intends to develop a variety of new processes, including innovative sorting technology; pretreatment of recycled PET plastic components using the Carbios depolymerization process; repolymerization; and the manufacture and quality verification of new products from recycled materials.

PET Bottle Recycling Plant

Reaction technology

PET manufacturer Equipolymers and technology start-up Rittec Umwelttechnik announced a collaboration in Scherbau, Germany earlier last year to further develop Rittec’s RevolPET process and implement it in Equipolymers PET manufacturing plants. The companies plan to use materials that are not suitable for mechanical recycling, including multilayer packaging and highly colored containers.

Laboratory-scale aggregation tests have shown promising results. “For us, it is feasible to replace virgin raw materials,” says Olaf Hempel, development manager at Equipolymers. The RevolPET process is capable of producing terephthalic acid (TA) and ethylene glycol (MEG). .

The technology, part of a research and development project supported by the German Federal Ministry of Education and Research (BMBF) in cooperation with the Institute of Chemical and Thermal Process Engineering (ICTV) of the TU Braunschweig, is based on solid-solid reactions in standard extruders.

“Specially, we directly use the energy released during the reaction,” says Rittec. “This speeds up subsequent reactions. The self-contained system takes less than a minute to process. During this time, more than 95 percent of the PET polymer is decomposed.” The process is also highly tolerant to contaminants.

 

Molecular recovery

In September 2022, Koch Technology Solutions (KTS) and Ioniqa Technologies announced a partnership to scale up and commercialize Ioniqa’s PET recycling technology. As part of this collaboration, Koch Technologies has committed to invest up to EUR 30 million in Ioniqa Technologies, a spin-out company of Eindhoven University of Technology. The Ioniqa depolymerization process can convert low-grade post-consumer PET into BHT (bis-2-hydroxyethyl terephthalate) monomer using glycolysis. The process has been proven at the 10,000 t/y production facility that supplies Indorama.

 

Ioniqa CEO and founder Tonis Hooghoudt said the partnership with Koch Technologies is “an important springboard for Ioniqa to commercialize its technology globally. Our expertise in ‘waste depolymerization’ The knowledge is a perfect match with KTS’ experience in designing and licensing PET production processes around the world.”

 

Also last September, Interzero and Eastman announced a long-term supply agreement for Eastman’s planned recycling facility in Normandy, France, which will use methanolysis. Interzero will process up to 20,000 tonnes of difficult-to-recycle PET household packaging waste each year, which the partners say would otherwise be incinerated. Interzero Plastics Recycling is part of Interzero and has the largest plastic sorting capacity in Europe.

 

Eastman said the company’s facility “will be the largest material-to-material molecule recycling facility in the world.” When completed, the facility will recycle approximately 160,000 tonnes of polyester waste per year. The project, expected to be operational by 2025, will process colored and opaque PET waste that cannot be recycled mechanically.