A CHEMCAD COLLABORATION: Studying Best Practices for closing the loop on PET Recycling

Post-consumer polyethylene terephthalate (PET) waste has traditionally had a poor track record in the U.S. of being effectively recycled. When a group of researchers led by Utkarsh S. Chaudhari of Michigan Technological University set out to compare the different methods to recycle PET using solvent-based dissolution and precipitation, they chose CHEMCAD as the process simulator to help tackle the study. Chemstations worked with MTU as part of a project funded by the REMADE Institute, with our Senior Technical Support Engineer Alejandra Peralta consulting on the project.

From the study's abstract:

"Due to challenges in closed-loop recycling of PET, recycle rates in the U.S. are low (13% compared to PET resin converted), with the vast majority landfilled or leaked to the environment at the end of life. Solvent based dissolution and precipitation recycling technology has the potential to achieve closed-loop recycling of PET in food packaging and help achieve a circular economy for plastics. However, this technology is still in the early stages of development and there is an urgent need to understand the economic costs and environmental impacts to select promising process pathways. In this study, we analyze three precipitation process configurations for production of high-quality PET resin from post-consumer waste PET using gamma-valerolactone as the solvent: (i) anti-solvent using water, (ii) solvent evaporation, and (iii) cooling of the dissolved polymer solution. The process conditions and yields were obtained from literature sources, and process simulation was employed to estimate energy consumption and process economics."

The researchers chose the UNIFAC thermodynamic package to best fit the process temperature and pressure ranges in their simulation, as well as the components involved.

To read the full article from the Royal Society of Chemistry's journal RSC Sustainability, click here.