Recycling mixed plastic waste streams from end-of-life vehicles that have been combined with biomass in a gasification process to create new feedstocks can reduce greenhouse gas emissions when compared with incineration for energy recovery.
BASF said that analysis by ETH Zurich had found that instead of incinerating automotive shredder residues and biomass to generate electricity and steam, the gasification of a mixture of waste plastics and biomass produces both steam and synthesis gas – which can then be used as a feedstock for chemicals, reducing the need for consumption of virgin fossil fuels.
The analysis by the Swiss university found that the recycling of 1kg of automotive shredder residues with 3kg of biomass reduces greenhouse gas emissions by more than 3 kg CO2-equivalent as compared to their incineration for energy recovery.
What is new here is the integration of plastic waste coming from the automotive shredder residue into the gasification process, which BASF said unlocks a significant volume potential of plastic waste that is currently incinerated or sent to landfill.
Over one million tons of automotive plastic waste is being either incinerated or landfilled in Europe every year. While there are opportunities to sort out more plastic waste for mechanical recycling, there always remains a residual mixed plastic waste stream.
However, for feedstocks made from recycled plastic waste to replace fossil fuels, a supportive legal framework is required that acknowledges mixed plastic waste as recyclable and sets long-term targets to allow for the transition to this recycled feedstock.
BASF said that while legislation already supports gasification of bio-waste – which has led to investments in maritime and aviation fuel - there is no comparable support for recycling plastic waste streams via gasification.
"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," said Martin Jung, president of BASF’s Performance Materials division.
Recycling technologies, such as chemical recycling through gasification are required depending on the type of waste and the degree of sorting BASF said. “Those technologies require the acceptance of a broad and flexible mass balance approach for the chemical industry. This is where the support from policymaking is needed,” the company said.
BASF added “Gasification of biomass is accepted by regulators for use in, for example, sustainable aviation fuel. Gasification of plastic waste streams, for example, from automotive shredders, is not regulated/accepted yet.”
The findings by BASF and ETH Zurich follow on from a gasification pilot project that BASF and Porsche carried out in partnership with their technology partner Bioenergy and Sustainable Technologies (BEST) during the middle of this year. That pilot project demonstrated the recyclability of high-performance plastics from automotive shredder residues mixed with renewable raw materials and showed that these automotive wastes can be recycled through gasification and returned to the automotive cycle. The partners said that this was the first time that such materials had been gasified as a mixture.
The resulting recycled raw material - the so-called synthesis gas and its derivatives - replaced the fossil-based raw materials in BASF's integrated value chain. Within its production network, BASF then produced the polyurethane formulation needed for the steering wheel using a mass balance approach.
Dr Matthias Kuba, area manager syngas platform technologies at BEST, said the plant had 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. This form of chemical recycling has great potential for converting complex, mixed waste streams into new, valuable raw materials. It represents a sensible alternative to waste incineration."
Visit Blog