Évaluation de l'influence des données d'inventaires sur les résultats de l'analyse du cycle de vie du tannage du cuir

Abstract

Life cycle assessment (LCA) is widely used to evaluate the environmental performance of industrial processes. However, the reliability of LCA results depends on the quality of the life cycle inventory (LCI) data. Leather tanning is a complex industrial process due to the diversity of material flow, physicochemical transformations, and material losses, all of which may influence LCA results. This thesis investigates the influence of life cycle inventory data quality on the results of an LCA applied to the industrial chrome leather tanning process. Four mass balance correction approaches were developed to evaluate the effect of difference modeling assumptions on the calculated environmental impacts. In addition, a statistical analysis based on a Box-Behnken experimental design was performed to identify the physical parameters having the greatest influence on mass balance closure. The results show that the thickness and density of crust and finished leather (ecfl et dcfl) are the most influential parameters affecting the process. A sensitivity analysis based on the application of the cut-off principle to by-products shows that the differences in absolute impacts among the modeling approaches are due to the by-product management assumption. Excluding sold or recycled by-products from the system leads to the four modeling approaches to converge toward identical absolute impacts. The remaining differences in impacts expressed per kilogram of finished leather are therefore solely attributable to the denominator associated with the functional unit, whereas impacts expressed per square meter of finished leather are more stable. The combination of mass balance analysis, statistical analysis, and LCA provides a relevant methodological approach for improving the robustness of life cycle inventory data and the reliability of environmental assessments of complex industrial processes. This study is limited by the detailed analysis of a single tannery, the use of several proxies for certain inputs, and the assessment of only the impact category. Nevertheless, it highlights the importance of inventory data quality, functional unit section, and proper documentation of by-product destinations. Future work could extend the analysis to multiple sites, explicitly incorporate moisture content, consider additional impact category, and evaluate alternative by-products management and recovery scenarios.

Date	10 Sept 2026
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Andrew Henderson (Supervisor)