Mixed plastics, new raw materials: the University of Amsterdam's pilot reactor

Not every collected plastic item can be readily recycled through mechanical processes. Mixed and contaminated packaging, in particular, can require extensive sorting. A University of Amsterdam team is testing a chemical route to recover some of its value.

According to the university's announcement, a process called solvothermal liquefaction uses solvent, heat, catalysts and pressure to turn mixed plastic waste into gas, oil and a solid residue. In laboratory experiments, the reaction produced these materials in about 30 minutes. The oil contains molecules that could potentially serve as feedstock for new plastics.

The next step is a pilot plant with a 25-litre reactor. The system was due to be tested in Spain at public waste-management company COGERSA using real municipal plastic waste. That is where performance, safety, cost and product quality must be assessed under less controlled conditions.

This does not mean every mixed plastic can already become new packaging. The technology is at the demonstration stage, not widespread industrial use. Reducing unnecessary packaging, designing for reuse and separating materials well will remain important even if chemical recycling advances.

The cover is an AI-generated illustration, not a photograph of the pilot plant.

Source: University of Amsterdam, June 2, 2026.