Operations are planned to start up soon at a first-of-its-kind recycling demonstration plant in Monthey, Switzerland. Employing a proprietary reaction technology developed by DePoly S.A. (Sion, Switzerland; www.depoly.co), the plant is set to treat up to 500 tons/yr of polyethylene terephthalate (PET), as well as polyester and other difficult-to-recycle post-consumer materials. DePoly currently operates a PET-recycling pilot plant in Sion, which has a nameplate capacity of 50 tons/yr, and this new “showcase” site in Monthey will further expand the technology’s feedstock versatility.
Source: DePoly
“DePoly’s technology is based on a hydrolysis reaction using a combination of commodity chemicals that are safe and abundantly available. No heat or pressure is added to the process, so it is efficient and low-impact,” explains Samantha Anderson, chief executive officer and co-founder of DePoly. When fed PET, the reaction yields two monomers — purified terephthalic acid (PTA) and mono-ethylene glycol (MEG).
Beyond PET, the reaction can also be used to selectively depolymerize a variety of other materials with ester bonds, such as polyurethanes and polylactic acid, from unsorted post-consumer waste streams. “The process does not target materials like polyethylene, polypropylene, polycarbonates, cotton, elastane, nylon, acrylic or any polymer that is not susceptible to hydrolysis. We are therefore able to separate and recover these materials, if any are present in the feedstock,” says Anderson. This enables seamless recycling for many materials that are traditionally challenging to recycle, including colored fabrics and multilayered materials. “The new showcase plant in Monthey will run on several feedstocks. Both textiles and post-consumer plastics will be used to demonstrate the robustness of the process,” says Anderson. The next step will be a commercial-scale plant, which the company is planning to build in 2027 to process significantly larger volumes of waste.