The present paper aims to investigate the environmental impacts of a real municipal solid waste management facility operating in Italy including two power units, i.e., a combined heat and power system and an internal combustion engine, fed by the biogas produced from anaerobic digestion and waste disposal in sanitary landfill. The Life Cycle Assessment study is carried out in Simapro 9.1.1.7 and, in addition to the base case scenario, the implementation of additional renewable energy and circular economy solutions is evaluated. More precisely a PV plant on the roof of the anaerobic digesters section and the use of plastic and paper residues in a gasification process for additional heat and power production are considered. The main outcomes of the simulations demonstrate the following: (i) the benefits in terms of energy and fuel savings provided by the two power units; (ii) the environmental impact reduction due to the compost obtained from the anaerobic digestion of the organic waste as potential fertilizer; (iii) a potential power capacity of 2 MW through the gasification of the plastic and paper residues. With reference to the latter, despite bringing an increase of the carbon emissions (+48%) compared to the base case, it could contribute to reach higher environmental standards for MSW composting facilities.

In the last decade, growing awareness about CO2 emissions is supporting the authorities in a more sustainable society. The proposed solutions embrace different topics, such as renewable energy implementation, lower waste production, and carbon capture and storage technologies (CCS). The latter is based upon the best available knowledge about the thermophysical properties of CO2, which are not always satisfactory for its complete characterization. In this work, it is investigated the interaction of the CO2 in solid phase (dry-ice) with sandy soil, a phenomenon that can potentially occur following pipeline ruptures. An experimental setup and a numerical model have been developed to measure and validate the temperature profiles beneath the dry-ice bank at steady-state conditions. The model has been validated with the experimental data by defining a suitable range of the thermal conductivity at the solid phase (0.25–0.30 W m−1 K−1) that led to the best match (deviation of 7.81%). Finally, the overall heat transfer coefficient (85.56–86.35 W m−2 K−1) has been numerically calculated.

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The utilization of carbon dioxide in new technologies opens a wide range of interesting applications which depend strictly upon heat transfer phenomena. The momentum on the deployment of Carbon Capture Utilization and Storage (CCUS) infrastructures will potentially enlarge the diffusion of technologies for the utilization and recycling of CO2. Such applications, however, require appropriate laboratory investigations for a complete characterization of the CO2 thermo-fluid-dynamic behaviour. The safety management of carbon dioxide is important; thus, accurate modelling is needed since solidification and sublimation of dry-ice can be very challenging to predict analytically. One of the dry-ice applications is the utilisation in refrigeration cycles and in novel CO2 heat pump technologies. For this reason, knowledge about the entity of sublimating CO2 from a solid surface is crucial. This work proposes an innovative experimental setup for the measurement of temperature and convective velocity fields in the sublimating phenomenon of CO2 under atmospheric conditions by means of Particle Image Velocimetry (PIV). The experimental results have been compared and validated with numeric CFD models.