Assessment of energy, mobility, waste, and water management on Italian small islands

Small islands are recognized for their vulnerability to climate change. In this context, mitigation and adaptation policies are needed, but the ecological transition must be based on data. This study aims to assess the level of sustainability reached by 26 of the inhabited Italian small islands; it collects and analyzes the data and initiatives on the energy, mobility, waste, and water sectors and discusses the islands’ steps toward sustainability. The findings show that 18 of the 26 islands are not interconnected with the national grid and that the renewable sources cover less than 5% of the energy demand on 25 of the 26 islands. The number per capita of private vehicles reaches 90 cars per 100 inhabitants on three islands. The average of the separate collection of waste on the islands is 52%, which is far from the minimum recommended threshold of 65%. Pipelines or tankers on 17 of the 26 islands guarantee the water supply, and desalination plants are still not the rule, while the presence of wastewater treatment has been detected on 12 islands, and it often provides only partial treatment. An ambitious multi-stakeholder sustainability plan for each island should be developed to overcome the typical barriers of the island and to increase the building capacity in order to use economic incentives for that goal

Liquefied biomethane for heavy-duty transport in Italy. A well-to-wheels approach

While environmental benefits of biofuels in general are well known, the impact of liquefaction and carbon capture to the biomethane production chains are yet to be explored. Hence, a well-to-wheels (WtW) analysis of liquified biomethane (bio-LNG, or LBM) production chains was performed; Italy was chosen as case study, having more than 25% of EU methane refuelling stations. Despite increased emissions from the liquefaction process, LBM reaches a negative impact of −572 gCO2eq/km, as it addresses transport emissions and agricultural waste management at the same time. Nitrous oxides (NOx) emissions for biomethane and fossil fuels are mostly similar, as fuel combustion in the vehicle engine is a predominant source of NOx emissions compared to fuel production. The most intensive processes contributing to climate change were biomethane upgrading and liquefaction. Small-scale CO2 capture can provide additional GHG emissions reductions by 7.55 gCO2eq/MJ although this process is also more NOx-intensive compared to other production steps

Sustainable additives for the regulation of NH3 concentration and emissions during the production of biomethane and biohydrogen. A review

: This study reviews the recent advances and innovations in the application of additives to improve biomethane and biohydrogen production. Biochar, nanostructured materials, novel biopolymers, zeolites, and clays are described in terms of chemical composition, properties and impact on anaerobic digestion, dark fermentation, and photofermentation. These additives can have both a simple physical effect of microbial adhesion and growth, and a more complex biochemical impact on the regulation of key parameters for CH4 and H2 production: in this study, these effects in different experimental conditions are reviewed and described. The considered parameters include pH, volatile fatty acids (VFA), C:N ratio, and NH3; additionally, the global impact on the total production yield of biogas and bioH2 is reviewed. A special focus is given to NH3, due to its strong inhibition effect towards methanogens, and its contribution to digestate quality, leaching, and emissions into the atmosphere