BASF and ETH Zurich Advance Mixed Plastic Waste Gasification

Gasification of automotive shredder plastic with biomass lowers CO₂ emissions and creates circular feedstock for chemical production.

BASF has worked with ETH Zurich to recycle automotive shredder residue combined with bio-waste. Together, they aim to transform these materials into high-value chemical feedstock. The research demonstrates the technical feasibility of chemical recycling through gasification for mixed plastic waste.

The ETH study follows a 2025 gasification pilot project conducted by BASF and BEST GmbH, an Austrian-based company. During the project, BEST treated plastic waste from automotive shredder residue, along with biomass, at its gasification pilot plant.

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Instead of incinerating plastics and biomass to generate electricity and steam, co-gasification produces steam and synthesis gas. This synthesis gas serves as a valuable feedstock for chemicals. Therefore, it can replace fossil resources, lower emissions, and keep carbon in the loop.

“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,” says André Bardow, professor at ETH Zurich.

The results are promising. Recycling 1 kg of automotive shredder residue with 3 kg of biomass reduces greenhouse gas emissions by more than 3 kg CO₂-eq. This reduction was measured against incineration with energy recovery on a cradle-to-gate basis.

A Promising Start

The first pilot project also involved Porsche AG and focused on the recovery of automotive shredder residue. This stream includes plastic, film, paint, and foam residues. The main goal was to reduce primary material use and increase recycled plastic content in vehicles.

“Pilot projects like these allow us to evaluate how we can further develop the circular economy as a sustainability field at Porsche and how we can anchor chemical recycling in our strategy in the long term,” says Dr. Robert Kallenberg, head of sustainability at Porsche AG. “We are testing new recycling technologies with our direct partners in order to increase recyclate quotas, gain access to previously unusable recyclate sources and evaluate new processes for waste streams that are currently being thermally utilized.”

As part of the project, Porsche used chemically recycled material in the manufacturing process for steering wheels. The recycled raw material consists of synthesis gas and its derivatives. BASF can use these materials to replace fossil raw materials in its integrated value chain.

The project used BEST’s gasification technology to convert plastic waste and other residues into synthesis gas at high temperatures. “In our plant, we have previously converted biomass such as wood or straw into chemical raw materials. In this pilot project together with BASF and Porsche, we have now used this gasification technology for the first time to convert complex plastic waste streams together with biomass into synthetic crude oil, known as syncrude,” explains Dr. Matthias Kuba, area manager for Syngas Platform Technologies at BEST – Bioenergy and Sustainable Technologies GmbH in Vienna.

Legal Recognition Required

To replace fossil feedstocks, companies need a legal framework that supports alternatives made from plastic waste and bio-waste. Therefore, policymakers should recognize mixed plastic waste as recyclable through gasification. They should also set long-term targets for this replacement route.

“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,” states Prof. Catharina Bening from ETH Zurich.

Current legislation already supports the gasification of bio-waste. As a result, companies have started investing in maritime and aviation fuels based on bio-waste. However, policy support for recycling plastic waste streams through gasification remains limited.

According to Martin Jung, president of BASF’s Performance Materials division, separate gasification plants for bio-waste and plastic waste are inefficient. “Instead, we call for policy to enable a multi-purpose of the plants through an audited, flexible mass balance approach,” he explains.

Looking Ahead

BASF reports that Europe incinerates or landfills more than one million tons of automotive plastic waste every year. Some of this material can enter mechanical or solvent-based recycling. However, a residual mixed plastic waste stream always remains.

The research results show that companies can recycle this residual stream alongside biomass in a multi-purpose asset. In addition, the process produces lower CO₂ emissions than incineration with energy recovery.

Because the new circular raw materials have high quality, the resulting plastics can match the quality of virgin products. This performance matters for automotive components because safety standards remain especially demanding.

Chemical Recycling and Mass Balance

Chemical recycling can process plastic waste that cannot be mechanically recycled for technical, economic, or ecological reasons. Gasification is one form of chemical recycling. It converts highly mixed waste streams into valuable raw materials for plastics production.

BASF can feed these circular raw materials into large, complex, and continuously operated production plants such as the Verbund. There, they mix with conventional fossil raw materials and become plastic precursors. Companies then attribute the secondary raw materials through the mass balance approach.

Independent auditors certify products and sites according to internationally recognized systems such as ISCC PLUS or REDcert. Because the new raw materials have high quality, the resulting products can meet demanding high-performance plastics requirements. These requirements are especially important for safety-relevant automotive components.