On the impact of methodological configurations and data variations on chemical recycling life cycle assessment studies
Abstract
The comparability of Life Cycle Assessment studies on chemical recycling processes for plastic waste conversion is challenging due to the wide range of investigated feedstocks, datasets, and methodological choices. Thus, this paper investigates the impact of various degrees of freedom within peer-reviewed Life Cycle Assessments of chemical recycling processes on the proposed environmental impact. In detail, methodological degrees of freedom, such as system boundary depth, functional units, allocation methods, and the utilization of substitution credits, as well as data-related degrees of freedom, including the use of plant-level, model-based, literature-derived, or third-party data at different data scales, such as experimental, laboratory, or pilot scale, are considered. Among the investigated Life Cycle Assessment studies, none of them applied the same combination of methodological choices, highlighting the methodological uniqueness of each study. However, changes in either methodological or data-related degrees of freedom substantially affect Life Cycle Assessment results in both magnitude and interpretation: without changing the methodology, data-related degrees of freedom shift the global warming potential for 1 kg of treated waste from 2.5 kg CO2-eq. below that of incineration as the reference waste treatment process to 0.5 kg CO2-eq. above. Utilizing the same database, methodological differences as reported in the investigated studies shift the global The underlined authors contributed equally and share first authorship. warming potential from 2.9 below to 0.3 kg CO2-eq. above the global warming potential of incineration. The same trend is found when comparing the products of chemical recycling to the fossil-based production routes, where the main levers affecting the results were identified as the declaration of products, the handling of side streams, and the choice of energy sources. These findings show that LCA results should not be interpreted on the basis of individual values alone, but in the context of methodological choices, data sources and quality, and sensitivity to both data and methodological assumptions. Without transparency regarding these aspects, reported values are of limited interpretive value and may offer unwanted possibilities for selective interpretation and may ultimately increase the risk of greenwashing in the communication of chemical recycling performance.
Related
- Assessment of regional and interannual variations in tropospheric ozone in chemical reanalyses
- A Unified Classification of Waste Plastic Chemical Recycling: Pyrolysis, Gasification, Depolymerization, and Dissolution.
- From process simulation to circular value: environmental-economic assessment of advanced recycling for end-of-life photovoltaics
- Feedstock-Informed Technology Selection for Chemical Recycling of Plastic Rejects: An Integrated Physicochemical Characterization and Multi-Criteria Decision Framework
- Assessment of the Seasonal Variations in Heavy Metals Concentration in the Ughelli Central Market River, Delta State, Nigeria
BibTeX
@misc{biessey2026impact,
title = {{On the impact of methodological configurations and data variations on chemical recycling life cycle assessment studies}},
author = {Philip Biessey and Darius Steegborn and Meike Islamoglu and Lucas Wieczorek and Yu-Yi Lin and Manfred Renner},
howpublished = {ChemRxiv},
year = {2026},
month = oct,
doi = {10.26434/chemrxiv.15010151/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010151/v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - On the impact of methodological configurations and data variations on chemical recycling life cycle assessment studies
AU - Philip Biessey
AU - Darius Steegborn
AU - Meike Islamoglu
AU - Lucas Wieczorek
AU - Yu-Yi Lin
AU - Manfred Renner
PY - 2026
DA - 2026/10/09
PB - ChemRxiv
DO - 10.26434/chemrxiv.15010151/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010151/v1
AB - The comparability of Life Cycle Assessment studies on chemical recycling processes for plastic waste conversion is challenging due to the wide range of investigated feedstocks, datasets, and methodological choices. Thus, this paper investigates the impact of various degrees of freedom within peer-reviewed Life Cycle Assessments of chemical recycling processes on the proposed environmental impact. In detail, methodological degrees of freedom, such as system boundary depth, functional units, allocation methods, and the utilization of substitution credits, as well as data-related degrees of freedom, including the use of plant-level, model-based, literature-derived, or third-party data at different data scales, such as experimental, laboratory, or pilot scale, are considered. Among the investigated Life Cycle Assessment studies, none of them applied the same combination of methodological choices, highlighting the methodological uniqueness of each study. However, changes in either methodological or data-related degrees of freedom substantially affect Life Cycle Assessment results in both magnitude and interpretation: without changing the methodology, data-related degrees of freedom shift the global warming potential for 1 kg of treated waste from 2.5 kg CO2-eq. below that of incineration as the reference waste treatment process to 0.5 kg CO2-eq. above. Utilizing the same database, methodological differences as reported in the investigated studies shift the global The underlined authors contributed equally and share first authorship. warming potential from 2.9 below to 0.3 kg CO2-eq. above the global warming potential of incineration. The same trend is found when comparing the products of chemical recycling to the fossil-based production routes, where the main levers affecting the results were identified as the declaration of products, the handling of side streams, and the choice of energy sources. These findings show that LCA results should not be interpreted on the basis of individual values alone, but in the context of methodological choices, data sources and quality, and sensitivity to both data and methodological assumptions. Without transparency regarding these aspects, reported values are of limited interpretive value and may offer unwanted possibilities for selective interpretation and may ultimately increase the risk of greenwashing in the communication of chemical recycling performance.
ER -