Camilla Tua’s research while affiliated with Politecnico di Milano and other places

In the recent years, packaging made of conventional plastics has been increasingly replaced by materials believed to be more sustainable. However, perceived sustainability must align with scientific assessments, such as life cycle assessments (LCAs). This review analysed 53 peer-reviewed studies published in the time range 2019–2023, aiming at understanding the state of the art in LCA about the environmental impacts of packaging by focusing on the comparison between plastics and alternative materials. The literature showed that consumer perceptions often differ from LCA findings and revealed that, frequently, conventional plastics are not the least environmentally friendly choice. Bioplastics typically show benefits only in the climate change and the fossil resource depletion impact categories. The heavy weight of glass turns out to affect its environmental performances with respect to the light plastics, with reuse being an essential strategy to lower the burdens. The comparison between plastics and metals is more balanced, leaning more towards plastics for food packaging. Similarly, article resulted often preferable than plastics. Finally, for the other materials (i.e. wood and textiles), the picture is variable. To be competitive with plastics, the alternative materials require improvements like the optimisation of their production processes, their reuse and enhanced end-of-life options. At the same time, recycled polymers could boost the eco-performance of virgin plastics.

The consumption of bottled mineral water in Italy is amongst the highest at the European level. This life cycle assessment (LCA) aims to evaluate the environmental impacts associated with the distribution of mineral water in the Italian hospitality industry, that is less investigated than the domestic consumption in the existing literature. The use of traditional one-way PolyEthylene Terephthalate (PET) bottles of small format (0.5 L) was compared with the alternative system of refillable, 1 L, glass bottles. Primary inventory data were collected to describe the system. The evaluation considered 14 impact indicators calculated according to the Environmental Footprint method. LCA results support the replacement of plastic with glass containers in the hospitality industry only in the best conditions for the glass bottles (more than 25 uses and a local distribution) and simultaneously in the worst situation for PET (bottles of small format and 100% from virgin granulate). When a recycled PET bottle is considered, results become heavily in favour of the single-use PET system. The following recommendations were derived for increasing the environmental sustainability of the distribution of bottled water in the Italian hospitality industry: to move towards a PET bottle closed loop system, in which discarded PET bottles are recycled to produce bottle-grade granules; to promote a progressive light weighting of refillable glass bottles, compatibly with the bottle resistance and to ensure at least 25 reuses before their disposal; to promote the sale of bottled water from local bottling companies (no more than 300 km distance from the final client).

Lime is a product derived from the thermal decomposition of limestone (mainly calcium carbonate, CaCO3) into quicklime (CaO) and carbon dioxide (CO2), also called calcination. Controlled reaction with water is used to manufacture hydrated lime (Ca(OH)2) products. Lime is used in a wide variety of applications: metals industry, construction materials sector, civil engineering, environmental protection, agriculture, and chemical industry. Lime production is one of the sources of anthropogenic CO2 emissions resulting in global warming and ocean acidification. However, a proportion of the CO2 emitted during the calcination is reabsorbed by the lime during the product life within its different applications. This process called carbonation is thermodynamically favoured because it is exothermal. It allows permanent CO2 storage in a stable product since the lime combines with gaseous CO2 reforming CaCO3. This paper reports a comprehensive literature review on the carbonation potential of lime in different applications. The total carbonation potential is assessed as carbonation rate, i.e. the ratio between the CO2 reabsorbed through carbonation during the operational life of lime and the CO2 emitted during limestone calcination. This study provided preliminary evidence that, based on the current EU market, on average 23–33% of lime process emissions are carbonated during the use phase. Carbonation over time is also analysed for the lime applications where information is available. For three applications, namely water, flue gas cleaning and pulp and paper, the carbonation reaction is instantaneous. Up to 22% of the calcination emissions are absorbed within five years based on the current EU market.

Re-use of packaging items plays a key role in the achievement of sustainable management of resources, one of the key aims of the circular economy concept. In this study, the environmental impacts of the life cycle of glass bottles used for mineral water have been assessed as a function of the number of uses (the so-called “rotations”) by applying the life cycle assessment (LCA) methodology. The research is part of a wider project on the evaluation of the environmental impacts and benefits associated with the re-use of packaging in Italy. The study has been performed to identify the contribution of the reconditioning process to the total impacts of the life cycle of reusable glass bottles and to compare the environmental performances of this system with those of a system based on single-use bottles. The production of the bottles, their washing and end of life have been included in the system boundaries, as well as the logistic for the delivery to the final user (that differs among the reusable and single-use bottles-based systems). The study was built up mainly on primary data acquired through a detailed inventory questionnaire delivered to some Italian mineral water companies that use reusable glass bottles, and complemented by field visits to two reconditioning plants.

The European packaging market is forecast to grow 1.9% annually in the next years, with an increasing use of returnable packages. In this context, it is important to assess the real environmental effectiveness of the packaging re-use practice in terms of environmental impacts. This life cycle assessment aims to evaluate the environmental performances of reusable plastic crates (RPCs), which are used for the distribution of 36% of fruit and vegetables in Italy. RPCs can be re-used several times after a reconditioning process, i.e., inspection, washing, and sanitization with hot water and chemicals. The analysis was performed considering 12 impact categories, as well as the cumulative energy demand indicator and a tailor-made water consumption indicator. The results show that when the RPCs are used for less than 20 deliveries, the impacts of the life cycle are dominated by the manufacturing stage. By increasing the number of deliveries, the contribution of the reconditioning process increases, reaching 30–70% of the overall impacts for 125 uses. A minimum of three deliveries of the RPCs is required in order to perform better than an alternative system where crates of the same capacity (but 60% lighter) are single-use. The same modeling approach can be used to evaluate the environmental sustainability of other types of returnable packages, in order to have a complete overview for the Italian context and other European countries.

In recent years, alternative food supply chains based on short distance production and delivery have been promoted as being more environmentally friendly than those applied by the traditional retailing system. An example is the supply of seasonal and possibly locally grown fruit and vegetables directly to customers inside a returnable crate (the so-called 'box scheme'). In addition to other claimed environmental and economic advantages, the box scheme is often listed among the packaging waste prevention measures. To check whether such a claim is soundly based, a life cycle assessment was carried out to verify the real environmental effectiveness of the box scheme in comparison to the Italian traditional distribution. The study focused on two reference products, carrots and apples, which are available in the crate all year round. An experience of a box scheme carried out in Italy was compared with some traditional scenarios where the product is distributed loose or packaged at the large-scale retail trade. The packaging waste generation, 13 impact indicators on environment and human health and energy consumptions were calculated. Results show that the analysed experience of the box scheme, as currently managed, cannot be considered a packaging waste prevention measure when compared with the traditional distribution of fruit and vegetables. The weaknesses of the alternative system were identified and some recommendations were given to improve its environmental performance.

Purpose The demand for household batteries is considerable in the European context with just over five billion placed on the market every year. Although disposable batteries account for the largest market share in Europe, the use of rechargeable batteries is promoted as a less waste generating and a more environmentally friendly practice. A comparative life cycle assessment was therefore carried out to verify this assertion. Methods The study compared, with a life cycle perspective, the use of disposable alkaline batteries to that of rechargeable NiMH batteries, considering the AA and AAA sizes. The comparison focused on the factors that were expected to have an higher influence on the results: consumer choices during the purchase for disposable devices (typology of battery pack, selected brand, which affects the production country, and mode of transport of batteries for the purchasing round trip) and during the use phase for rechargeable batteries (number of charge cycles and source of the electricity used for the recharge). The waste generation indicator, 13 midpoint impact indicators on the environment and the human health, and the Cumulative energy demand indicator were calculated in support of the assessment. Results and discussion For waste generation, the choice of NiMH rechargeable batteries is highly convenient also with a reduced number of uses. On the contrary, for the environmental indicators and the energy consumption, the picture is less straightforward, being heavily dependent on the number of charge cycles. For the impact categories Acidification, Human toxicity (cancer effects), and Particulate matter, an “inefficient” use of the rechargeable devices (for only 20 charge cycles or less) could cause higher impacts than the employment of disposable batteries. Moreover, for the Ozone depletion, NiMH batteries are hardly environmentally better than alkaline batteries even with 150 recharges. Conclusions and recommendations The number of uses of rechargeable batteries plays a key role on their environmental and energy performances. When compared to disposable batteries, a minimum number of 50 charge cycles permits a robust reduction of the potential impacts for all the analyzed indicators excluding the Ozone depletion. Hence, the use of rechargeable batteries should be mostly encouraged for high consumption devices such as cameras, torches, and electronic toys.