Outlining a comprehensive techno-economic approach to evaluate the performance of an advanced sorting plant for plastic waste recovery

Abstract

Mixed plastics from municipal solid waste are usually recycled in suitable Material Recovery Facilities (MRFs) following separate collection. These plants allow the sorting of individual plastics with variable performance depending on the technologies adopted. The evaluation of the performance of MRFs is also conducted with different approaches, even in terms of timescales, making the results difficult to compare. In this context, this study presents a comprehensive techno-economic approach to evaluate the performance of a MRF for plastic waste recovery. As a support, the Molfetta MRF case study (Southern Italy) was considered with an inlet plastic amount of about 19,000 t/year. The methodological proposal was based on the analysis of the quantity and composition of the different incoming waste streams, calculation of the Purity Index (PI) and Recovery Index (RI), quantification of the mass balance as well as accurate economic assessment. PI and RI assess the technical performance of the facility. They achieved the highest values (>95 %) for manual and optical sorting indeed they reached good values (70–80 %) for dimensional one; the economic analysis showed a specific gain of 12.58 €/t of sorted waste. The comparison of the obtained results with those of a similar MRF in Northern Italy had corroborated the suitability of the proposed approach suggesting its application, although with the due exceptions referred to the economic part, to other world contexts.