DOI: 10.3390/su18157956 ISSN: 2071-1050

Gate-to-Gate Benchmarking of Electricity Use and Electricity-Related CO2 Emissions in Mechanical Cable Recycling: A Descriptive Industrial Case Report from Poland

Małgorzata Hordyńska, Jerzy Łabaj, Piotr Madej, Monika Michalska, Anna Stasiuk-Piekarska, Jacek Zatoński

Cable scrap is a high-grade secondary copper resource, but transparent plant-scale evidence on the operational energy and emissions performance of mechanical separation lines remains limited. This descriptive industrial case report presents a non-replicated comparison of complete operating records for the former and newly implemented cable-recycling lines at MERCURY HM in Bielsko-Biała, Poland, for June 2022 and June 2024, respectively. Because each configuration is represented by one aggregate month, the comparison is descriptive and cannot support causal attribution or inferential statistical testing. The assessment applies a gate-to-gate boundary and quantifies location-based Scope 2 CO2 emissions from purchased electricity only; Scope 1 emissions, upstream and downstream Scope 3 emissions, equipment manufacture, transport, facility utilities, maintenance, and downstream metallurgical refining are outside the boundary. For consistent benchmarking, both months were recalculated using the same KOBiZE end-user electricity factor of 685 kg CO2/MWh. The functional units were one tonne of processed cable and one tonne of recovered copper. In the observed months, processed mass was 168 Mg for the former line and 288 Mg for the new line, while monthly electricity consumption was 30,000 and 23,000 kWh, respectively. Specific electricity consumption was 55.3% lower per tonne of cable and 55.8% lower per tonne of recovered copper in the June 2024 dataset; the corresponding electricity-related emission intensities were 122.3 versus 54.7 kg CO2/Mg of cable and 312.0 versus 138.0 kg CO2/Mg of recovered copper. Observed throughput was 0.6 versus 1.2 Mg/h, nominal capacity was 0.7 versus 2.25 Mg/h, and four samples of the high-purity copper product from the new line contained 99.48 ± 0.20% Cu. A scenario analysis for a cable copper content of 39–42% produced emission intensities of 297–320 kg CO2/Mg Cu for the former line and 131–142 kg CO2/Mg Cu for the new line. The results provide a transparent plant-specific sustainability-relevant benchmark, not a causal estimate of technology performance. Replicated monthly or batch-level data are required to test whether the observed differences persist after controlling for feedstock, ambient, operational, and workforce-related confounders.

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