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a b s t r a c tTransport of carbon dioxide is an essential feature of Carbon Capture and Storage. Power plants and industrial production plants -large point sources of CO 2 -are often situated far away from storage locations, thus it is necessary to transport the resulting CO 2 -rich streams from the point of capture to the storage/utilization site. The CO 2 quality required for transport may influence the choice of the capture technology and impose limits on the performance requirements.In order to design CO 2 transport networks, it is important to have an accurate knowledge of the thermodynamic properties of CO 2 -rich mixtures containing small amounts of impurities. However, a suitable equation of state under the appropriate conditions for pipeline transport has not been clearly defined yet and different options may be used for different applications. For a quick evaluation of transport options, simple cubic EOS may be sufficient, but for accurate measurements of CO 2 flows needed for fiscal purposes more accurate non-analytical EOS may be required.In this paper the results of different EOS, including both cubic equations and non-analytical equations, have been compared with P--T experimental data of binary mixtures of carbon dioxide with nitrogen, oxygen and argon obtained by the authors at the Energy and Environmental Laboratory of Piacenza (LEAP). Moreover a refitting of the mixture binary interaction parameters has been carried out for analyzed EOS.The Lee-Kesler-Plöcker, the Perturbated-Chain SAFT equations and the GERG model showed good prediction of the density of CO 2 -mixtures in the conditions typical of pipeline transport: "dense" liquid phase (P above the critical pressure and T below the critical temperature) and CO 2 molar concentration greater than 95%.Finally, the application of EOS to CO 2 transport simulations and pipeline design has been performed in order to find the best configuration of pipelines on the basis of geometrical characteristics and operating conditions.

Sustainability and waste management on board are key issues that need to be addressed by the maritime sector also in terms of greenhouse gas emissions (GHG). With the aim of evaluating waste management alternatives in a circular economy perspective, the study examines a combined system for the optimisation of ship waste management and assesses its possible use for energy purposes. Different systems are analysed in relation to their GHG emission reduction potential regardless of routes and ports of destination. A SWOT (Strengths, Weaknesses, Opportunities and Threats) analysis was carried out on waste management alternatives in order to preliminary identify their potential in terms of GHG emissions reduction, cost, environmental sustainability, methodological coherence, feasibility and replicability. Following this analysis, two case studies of particular interest were identified: (1) the thermo-chemical treatment of waste oils and sludge to obtain fuel oils; (2) the installation of a waste-to-energy plant and subsequent energy recovery on board. UNFCCC (United Nations Framework Convention on Climate Change) methodologies were applied to these two case studies to calculate GHG emission reduction resulting from their implementation. The obtained results are presented with the aim of supporting sustainable waste management strategies on board in a circular carbon economy perspective.

Often, power plants and industrial production plantslarge point sources of CO2are situated at long distances from storage locations; thus the transportation of the resulting CO2-rich streams, containing small amounts of impurities, is required from the point of capture to the storage site, making it very important to understand the thermodynamic properties of CO2-rich mixtures. The range of conditions studied in this work are of great interest for carbon capture and storage applications, in particular for pipeline transportation of CO2-mixtures. Pressure–density–temperature measurements were taken for binary mixtures of carbon dioxide with nitrogen, oxygen, or argon. Density was measured for all of the binary systems for temperatures between 273.15 K and 293.15 K and pressures between 1 MPa and 20 MPa, using a vibrating tube densimeter, Anton Paar DMA 512-HPM. The molar CO2 concentration was greater than 85 % for all mixtures tested.

An innovative water-treatment process consisting in reducing the nitrate concentration by using an active silica filter obtained from ashes produced during rice-straw thermal treatment has been developed by the LIFE LIBERNITRATE project. A life-cycle assessment (LCA) was carried out to evaluate the environmental impacts of this innovative process, from the production of ashes and extraction and activation of silica to the water treatment. These results were compared to the environmental impact derived from the use of bottled water, instead of tap water, where traditional water treatments (i.e., reverse osmosis) may not be available due to the high installation and operating costs. The comparison showed that the proposed innovative process could contribute to reducing the environmental impact in almost all analyzed impact categories (from 20% for photochemical oxidation to 90% for abiotic depletion) with respect to the use of bottled water. In addition, if conveniently optimized (for example reducing the amount of active silica used per day), the innovative process could further reduce the ecological footprint and be more eco-friendly than the use of bottled water and could be applied to treating water in small towns where reverse osmosis may not be installed. The LCA proved that the innovative process could contribute to reducing the environmental impact of water-treatment technologies resulting in lower environmental indicators with respect to the use of bottled water.