Operational Framework to Quantify "Quality of Recycling" across Different Material Types

Area of Science:

• Environmental Science
• Materials Science
• Circular Economy

Background:

• Recycling targets are often set without clear quality metrics, hindering effective waste management.
• A standardized method is needed to objectively assess the quality of recycling processes.

Purpose of the Study:

• To develop and present an operational framework for quantifying the quality of recycling.
• To establish a quantifiable metric for evaluating recycling performance beyond simple collection rates.

Main Methods:

• The framework integrates three dimensions: Virgin Displacement Potential (VDP), In-Use Stocks Lifetime (IUSL), and Environmental Impact (EI).
• Data are aggregated using a distance-to-target graph for comparative analysis.
• Case studies on poly(ethylene terephthalate) (PET) and glass recycling are presented.

Main Results:

• Deposit-refund system collected bottle and container glass achieved the highest recycling quality (distance-to-target: 1.05).
• Closed-loop mechanical recycling of PET bottles demonstrated high quality (distance to optimal: 0.96).
• Sensitivity analysis showed that increasing PET bottle collection rates could improve quality (distance-to-target: 0.75).

Conclusions:

• The developed framework provides a robust method for assessing and comparing recycling quality.
• Material-specific strategies, like deposit-refund systems for glass and closed-loop recycling for PET, are crucial for high-quality recycling.
• Optimizing collection rates is a key factor in enhancing overall recycling quality and achieving sustainability goals.