Solvent-resistant nano- and ultrafiltration: opening new perspectives in plastic recycling

RENOVATE aims to improve the quality of recycled plastics by removing unwanted additives, such as dyes, from plastic waste through nano- and ultrafiltration.



Over the last 50 years, plastics haven been optimised for an astounding number of applications: from food packaging to insulation materials and lightweight housing for electronic equipment. This optimisation did not only entail the modification of the polymer chemistry, but also the introduction of a whole range of highly functional additives.

Because of the diversity of plastics and additives and the huge variety in chemical compositions, recycling is not always straightforward.

Solvent soup

Solvent-based recycling might solve this challenge. Solvents are able to selectively dissolve polymers from a polymer mix, resulting in a so-called “solvent soup”. Then, whilst the solvents have liquefied the polymers, the polymer can be cleansed of unwanted additives.

Yet, the efficient and cost-effective cleaning of the complex solvent soup remains difficult. Solvent and energy use should be minimized. Inorganic and organic molecules should be removed from the solvent soup. Moreover, these steps need to be taken in quite a viscous and aggressive solvent environment.


RENOVATE seeks to address these issues by developing an energy-efficient and waste-free membrane technology to purify the solvent soup. This approach has multiple advantages. Non-solvents can be excluded, leaving a wider choice to select the most appropriate solvent and enabling the targeting of specific polymers or additives to be recovered. This way, solvent and non-solvent waste streams, potentially loaded with additives and polymer traces, are avoided.

Nano- and ultrafiltration

The project will employ new classes of highly stable membranes. Molecular weight cut-off values ranging from 200-1000 Da or above 1000 Da, referred to as nanofiltration and ultrafiltration respectively, will be used.


By developing a proof-of-concept for membrane-supported solvent-based recycling, RENOVATE will help Flemish industries recover polymers and additives from plastic waste, increase the use of recycled plastics in new products, and thus contribute to the circularity of carbon in materials.

Project details

Project type
ESI Project
Research trajectory
Project status
Approved on
Project date
€837 942

Project Partners