A new research study by ETH Zurich, conducted in collaboration with BASF SE, examines an alternative pathway for mixed plastic waste from end-of-life vehicles by co-gasifying automotive shredder residue with biomass. According to the study, recycling 1 kg of automotive shredder residue together with 3 kg of biomass reduces greenhouse gas emissions by more than 3 kg CO2-eq when compared with incineration for energy recovery. Beyond the climate benefit, the process generates synthesis gas that can be used as a circular feedstock in the chemical industry, displacing fossil resources and keeping carbon within industrial material cycles. The analysis arrives as the European Union prepares new legislation on end-of-life vehicles, giving the findings direct relevance for policymakers considering future recycling definitions and targets.
The ETH study follows a gasification pilot project run by BASF and BEST GmbH in Austria in mid-2025. For the first time, the pilot at BEST’s plant combined the gasification of biomass with plastic waste from automotive shredder residue. The work indicates that, instead of burning plastics and biomass solely to generate electricity and steam, co-gasification can produce both steam and synthesis gas. The resulting syngas serves as a valuable raw material for chemical production, thereby lowering demand for fossil feedstocks and associated emissions.
Commenting on the broader significance, André Bardow, Professor at ETH Zurich, said: "Closing the carbon loop by plastics recycling is not only beneficial for the climate but also crucial for conserving resources, an essential step toward a plastics industry that operates within planetary boundaries." The researchers also highlight the need for a supportive legal framework that recognizes mixed plastic waste streams as recyclable and sets long-term replacement targets for fossil feedstocks with alternatives derived from plastic waste and bio-waste. Prof. Catharina Bening from ETH Zurich stated: "Ambition in target-setting rather than opt-out and review clauses should be the baseline for policies that allow industries to reach ecological goals. Furthermore, sector-coupling and collaboration across industries is essential to speed up emission reductions." While current legislation already supports gasification of bio-waste, enabling first investments in maritime and aviation fuels, there is no comparable support for recycling plastic waste via gasification. Martin Jung, President of BASF’s Performance Materials division, added: "It is simply not efficient to operate separate gasification plants for bio-waste and for plastics waste streams. Instead, we call for policy to enable a multi-purpose of the plants through an audited, flexible mass balance approach."
Research scope and process implications
The study evaluates co-gasification as a recycling route for mixed plastic fractions that remain after sorting, particularly from automotive shredder residue. The approach contrasts with incineration for energy recovery by producing synthesis gas that can be integrated into chemical production chains. In doing so, it establishes a pathway for circular feedstocks to replace a portion of fossil inputs. The quantified climate benefit cited by the researchers underscores the potential for emissions reduction when co-processing plastic waste with biomass in a single multi-purpose asset.
Volume potential and material quality
Research referenced in the study estimates that more than one million tons of automotive plastic waste in Europe are either incinerated or landfilled each year. Although additional sorting can support mechanical recycling of certain fractions, a residual mixed plastic stream remains. The findings indicate that recycling this residual stream together with biomass is feasible in a multi-purpose plant and results in lower CO2 emissions than incineration for energy recovery. According to the study, the resulting circular raw materials enable production of plastics with the quality of new goods, meeting the performance requirements of high-performance applications, including safety-relevant automotive components.
ETH Zurich has shown in a new study that gasification of automotive shredder residue mixed with bio-waste saves greenhouse gas emissions if compared to incineration with energy recovery. At the same time a new, circular feedstock for the chemical industry is generated.
