Evaluation of Mussel Shells Powder as Reinforcement for PLA-Based Biocomposites.

The use of biopolyesters, as polymeric matrices, and natural fillers derived from wastes or by-products of food production to achieve biocomposites is nowadays a reality. The present paper aims to valorize mussel shells, 95% made of calcium carbonate (CaCO3), converting them into high-value added products. The objective of this work was to verify if CaCO3, obtained from Mediterranean Sea mussel shells, can be used as filler for a compostable matrix made of Polylactic acid (PLA) and Poly(butylene adipate-co-terephthalate) (PBAT). Thermal, mechanical, morphological and physical properties of these biocomposites were evaluated, and the micromechanical mechanism controlling stiffness and strength was investigated by analytical predictive models. The performances of these biocomposites were comparable with those of biocomposites produced with standard calcium carbonate. Thus, the present study has proved that the utilization of a waste, such as mussel shell, can become a resource for biocomposites production, and can be an effective option for further industrial scale-up.

Two-stage thermal pyrolysis of plastic solid waste: Set-up and operative conditions investigation for gaseous fuel production.

In response to the escalating global challenge of mounting plastic waste and the imperative to adopt more sustainable practices for resource utilization, our study focuses on the utilization of plastic solid waste (PSW) through a two-stage thermal pyrolysis process. This aims to demonstrate its potential as a high-performance alternative to existing two-stage catalytic pyrolysis methods. The experimentation involved processing real scrap PSW material in a lab-scale batch set-up, emphasizing optimizing residence time in the cracking reactor to maximize gas yield and its lower heating value (LHV). The study underscores the advantages of the employed two-stage thermal pyrolysis apparatus through a comparative analysis with established set-up dedicated to maximizing gas yield. Once the operative conditions were explored, resulting pyrolysis products underwent detailed characterization to assess their suitability as a sustainable fuel source. The study also presents a practical application of the produced gaseous fuel, envisioning its combustion in an internal combustion engine (ICE), known for its flexibility regarding fuel properties. This application is demonstrated through a simulation conducted in Unisim Design©. The successful processing of real PSW material in the two-stage lab-scale experimental set-up showcased optimal gas yield achievements (>65 % w/w) with an LHV (∼41 MJ/kg), comparable to that of natural gas. This emphasizes the potential of these sustainable alternatives to replace fossil fuels, especially in the context of ICE applications. The integration of the pyrolysis plant with an ICE demonstrated promising prospects for generating electricity in the transportation sector and facilitating thermal power for heat integration in pyrolysis reactors.