This study contains a significant methodological flaw in its semi-quantitative approach to product analysis via Py-GC-MS. The reliance on relative peak area percentages without proper calibration or internal standards undermines the validity of yield comparisons between samples. This approach fails to account for differences in detector response factors across diverse compound classes (e.g., aliphatics vs. oxygenates), making the reported abundances indicative rather than quantitatively reliable. Consequently, claims regarding the superior performance of aged plastics or the economic potential based on naphtha yields are built on uncertain quantitative foundations.
Furthermore, the paper overstates its conclusions by extrapolating laboratory-scale, controlled-mixture results to real-world economic and technical feasibility. The assumption that excavated mixed plastics can be efficiently processed into high-value chemicals ignores practical challenges such as feedstock heterogeneity, contamination, pre-treatment costs, and the presence of PVC/PET, which produce harmful contaminants like HCl, that were not adequately addressed at scale. The economic valuation of landfilled plastics is highly speculative, omitting critical costs related to excavation, sorting, cleaning, and catalytic upgrading required to produce refinery-ready naphtha, thereby presenting an overly optimistic and incomplete techno-economic picture.