Circular economy comes to break the linear resource to waste economy, by introducing different strategies, two of them being: using material from renewable sources and producing biodegradable products. The present work aims at developing polylactic acid (PLA), typically made from fermented plant starch, and polycaprolactone (PCL) blends, a biodegradable polyester, to study their potential to be used as substitutes of oil-based commodity plastics. For this, PLA/PCL blends were compounded in a batch and lab scale internal mixer and processed by means of injection molding. Tensile and impact characteristics were determined and compared to different thermoplastic materials, such as polypropylene, high density polyethylene, polystyrene, and others. It has been found that the incorporation of PCL into a PLA matrix can lead to materials in the range of 18.25 to 63.13 megapascals of tensile strength, 0.56 to 3.82 gigapascals of Young’s modulus, 12.65 to 3.27 percent of strain at maximum strength, and 35 to 2 kJ/m2 of notched impact strength. The evolution of the tensile strength fitted the Voigt and Reuss model, while Young’s modulus was successfully described by the rule of mixtures. Toughness of PLA was significantly improved with the incorporation of PCL, significantly increasing the energy required to fracture the specimens. Blends containing more than 20 wt% of PCL did not break when unnotched specimens were tested. Overall, it was found that the obtained PLA/PCL blends can constitute a strong and environmentally friendly alternative to oil-based commodity materials.
Sustainable packaging is a crucial focus in the context of circular economy efforts. This study evaluates the circularity of two secondary packaging systems used in Spanish fresh food produces: Reusable Plastic Crates and Single-use Cardboard Boxes. A Mass Flow Analysis was performed to assess the material flows in the production and use phases of both systems and two circular indicators were applied: the Material Circularity Indicator and Product Circular Indicator. While most previous studies for single-use packaging use these indicators at the product level, this study applies a system approach since the Reusable Plastic Crates can be reused 100 times. The functional unit was defined as the distribution of 1000 tonnes of fresh products, resulting in the distribution of 6,666,700 packages with 15 kg of products. The Material Circularity Indicator and Product Circular Indicator results show that Reusable Plastic Crates are more circular than Single-use Cardboard Boxes. The Product Circular Indicator provides a more comprehensive assessment of circularity by considering multiple life cycle stages, efficiency, and unrecoverable waste, resulting in a difference in circularity evaluations. The indicators used have limitations as they do not consider the resource stock. Further research is needed to explore this aspect.
The tourism industry, affected by COVID-19, must reduce greenhouse gas emissions. This study evaluated the environmental impact of three hotels in coastal and mountainous regions of Spain and Portugal using Life Cycle Assessment (LCA). Data was gathered via surveys in the Greentour tool. Results indicate that the 2-star hotel (focused on cultural-urban tourism) has the highest impacts in most categories, except for CC, FRD, and POF indicators. The 3-star hotel (beach tourism) contributes the most to CC and FRD indicators, while the hostel (nature-religious tourism) has the highest value in the POF indicator. LCA findings reveal that diesel consumption in the hostel and electricity usage in both the 2-star and 3-star hotels are major contributors to environmental impacts across various categories. Overall, evidence suggests that fossil fuel and electricity usage significantly affect tourism activities environmentally. Interestingly, this study highlights that a 2-star hotel can have a higher carbon footprint (CC indicator) compared to a 3-star hotel, challenging the notion that higher star ratings imply lower environmental impact.