How life cycle assessment makes recycling impacts measurable
How the “resources SAVED” methodology quantifies environmental impacts
For almost 20 years, Fraunhofer UMSICHT has examined how Interzero’s recycling activities affect primary resource use and greenhouse gas emissions compared with primary production. The interdisciplinary team in the Sustainability and Resources Management department includes experts in geoscience, chemistry, landscape ecology and engineering.
The methodology enables a material-stream-specific comparison of the primary resource requirements and greenhouse gas emissions of primary production with the inputs and emissions associated with keeping recyclable materials in the loop within the Interzero Group. First, the scientists determine the quantities of resources consumed and greenhouse gases released in primary production. They then assess the resource requirements and greenhouse gas emissions associated with recycling. The calculated difference between the two scenarios provides the result for each material stream, within the defined data, assumptions and system boundaries.
Life cycle assessment using polyethylene (PE) as an example
All process steps in manufacturing the plastic are taken into account, from crude-oil extraction and transport to the refinery through to distillation and polymerisation. The same approach is used for the secondary process, from collecting used plastics and sorting and processing them through to shredding and remelting them in an extruder to produce PE regranulate.
Fraunhofer UMSICHT uses Interzero recycling data and supplements it with data from specialist databases. The “LCA for Experts” software calculates the raw material requirements and greenhouse gas emissions of the primary-production and recycling scenarios. For one tonne of PE, the assessment identifies calculated savings of 3,870 kg of primary resources and 639 kg of greenhouse gas emissions for recycled PE compared with primary production. The results relate to the data, assumptions and system boundaries defined in the life cycle assessment.
Frequently asked questions regarding the study:
- What is the objective of Interzero’s “resources SAVED by recycling” study?
Interzero stands for the vision of a world without waste, in which raw materials are kept in the loop and waste is avoided wherever possible. Reliable figures help explain the assessed effects of recycling. To inform the public and support transparent sustainability communication, Interzero has the resource use and greenhouse gas emissions associated with its recycling activities assessed by Fraunhofer UMSICHT and compared with primary production.
- What data do the scientists use?
The life cycle assessment is based on a detailed comparison of primary production and recycling, including the relevant process steps. It combines Interzero data on material types, sorting and recovery volumes, transport and collection distances, vehicle types and energy requirements with database data on greenhouse gas emissions and resource use in primary production.
- Which material streams are the focus of the study?
The study currently considers five material streams: metals; waste electrical and electronic equipment; plastics and lightweight packaging; wood, paper, paperboard and cardboard; and glass.
- How is the study carried out?
Fraunhofer UMSICHT first prepares a questionnaire to record recycling processes and the primary products being replaced. Interzero collects the data, which Fraunhofer UMSICHT reviews. The scientists then create life cycle assessment models using “LCA for Experts”, compare recycling with primary production, and analyse and interpret the calculated results.
- Why is resource use assessed?
Recycling can reduce the need for newly extracted raw materials compared with primary production. At the same time, recycling itself requires inputs for collection, transport, sorting and processing. The life cycle assessment takes these inputs into account when comparing the two scenarios.
- How is resource conservation through recycling quantified?
The assessment covers non-renewable and renewable energy resources as well as material resources. Resource quantities are assigned to the recycling and primary-production scenarios. The calculated difference represents the resource savings in tonnes, within the methodology’s defined assumptions and system boundaries.
- What role can recycling play in relation to greenhouse gas emissions?
Keeping raw materials in the loop can contribute to avoiding greenhouse gas emissions compared with the respective primary-production scenario. The scale of the calculated effect depends on the material stream, the recycling process and the reference scenario used.
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