The evidence that only 9% of plastic produced to date has been recycled highlights that we cannot rely solely on existing recycling practice to fix our plastic problem. Most countries have some existing infrastructure to support mechanical recycling, but there is a lack of evidence around the other infrastructure that would be effective and economically viable to support the shift to a new plastics economy. To understand what the best infrastructure and methods to deal with plastic waste were, Recycling Technologies modelled Scotland’s household plastic waste. The Project Lodestar model compared material flows, yields, economics and environmental impacts for mechanical recycling alone versus three different types of facility that had mechanical and chemical recycling.

Modelled material flows in an advanced polymer recycling facility as determined in the Project Lodestar study. Image credit: Recycling Technologies.

The model found that for Scotland’s amount and composition of household plastic waste, using chemical recycling to keep non-mechanically-recycled plastic materials in the economy could bring an economic advantage over incineration and landfilling. Compared to mechanical recycling alone, modelling suggests that a facility with both mechanical and chemical reprocessing capabilities could increase revenue by 25% and decrease the payback time of the facility by 11%. This demonstrates the potential feasibility of an ‘all plastics’ sorting and recycling facility that uses both mechanical and chemical recycling.

The model found that for Scotland’s amount and composition of household plastic waste, using chemical recycling to keep non-mechanically-recycled plastic materials in the economy could bring an economic advantage over incineration and landfilling

The findings depended on the presence of landfill taxes and gate fees for incineration. Therefore, to understand the type of facility that would best support the transition to a new plastic economy for Aotearoa New Zealand, a similar model could be established based on the amount and composition of household waste, building in the costs and systems of our local context. The project also highlighted that reprocessing infrastructure alone is insufficient to improve recycling rates – packaging redesign, phasing out problematic types of plastic packaging, and a comprehensive and effective collection system are all essential parts of the equation.

A more detailed case study is available on the New Plastics Economy website.

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