Biowaste Management in Italy: Challenges and Perspectives

Abstract

The aim of this work is the development of a methodology for the technical and environmental assessment of biowaste valorization in 2G biorefineries. Italy was chosen as case study, considering years 2016–2017. Approach: the Italian context was evaluated through the following key parameters: Gross domestic power, climate, demography, and population density distribution described the Italian framework. The four most abundant biowaste categories were defined through their amounts and geo-localization: wastewater and sewage sludge (WSS, 4.06 Mt/y), organic fraction of municipal solid waste (OFMSW, 1.7 Mt/y), agricultural livestock waste (ALW, 5.7 Mt/y), and waste deriving from the food industry (FIW, 2.6 Mt/y). The geo-localization and quantitative evaluations of the available biowaste amounts were aimed at defining the dimension and localization of the biorefinery plant and at optimizing supply and transport chains, while the qualitative characteristic were aimed to evaluate the most promising process among thermo-valorization (TH) and anaerobic digestion (AD). Results: All considered biowastes were appropriate for biorefinery processes, since carbon content exceeds 40% and the carbon–nitrogen ratio was between 10 and 30. All biowaste categories were evaluated as feedstocks for two biorefinery processes: anaerobic digestion (AD) and thermo-valorization (TH) with energy recovery. Compared to TH, AD achieved in all cases the best performances in terms of produced energy and avoided CO2 emissions. The primary energy production of AD and TH for WSS, OFMSW, ALW, and FIW were respectively: 7.89 vs. 2.4 kWh/kg; 8.7 vs. 2.6 kWh/kg; 10.85 vs. 5.5 kWh/kg; and 12.5 vs. 7.8 kWh/kg. The main findings of this work were: the adoption of AD was technically more suitable than TH; AD increased the avoided CO2 emissions of 10%–89.9% depending on biowaste category.

Response Surface Methodology to Optimize Methane Production from Mesophilic Anaerobic Co-Digestion of Oily-Biological Sludge and Sugarcane Bagasse

“…Biomass is considered the best option for renewable and suitable energy that can replace a large portion of fossil fuels, besides solar and wind energy. Meanwhile, bioenergy will contribute to enhance developed countries' standard of life, as it is a potent source for biofuels [3][4][5].…”

The Circular Economy and Organic Fraction of Municipal Solid Waste Recycling Strategies

“…In addition, other works indicate biowaste processing in AD installations has a positive effect on the reduction of Greenhouse Gases emissions [39]. For example, in their paper, Demichelis et al concluded that for the case study of Italy biowaste treatment, avoided CO 2 emissions were increased between 10% and 89.9%, when applying AD instead thermal treatment [40]. The work of Zeller et al, analysing circular biowaste management options at city-region level, concludes that AD treatment combined with separate collection may be beneficial in terms of meeting environmental criteria (based on life cycle assessment) [41].…”

Potential of Sustainable Concept for Handling Organic Waste in Tunisia

“…Agricultural waste is defined as the residue from the growing and processing of raw agricultural products such as fruits, vegetables, poultry, and livestock [59]. However, agricultural activities depend on the geo-localization of the region as well as the activities of its citizens.…”

“…The substantial flows generated by the livestock and poultry sectors in Nebeul are due to the enhancement of agro-activities from traditional animal breeding, mainly for personal consumption or local market distribution to an active industrial production. Agricultural waste is defined as the residue from the growing and processing of raw agricultural products such as fruits, vegetables, poultry, and livestock [59]. However, agricultural activities depend on the geo-localization of the region as well as the activities of its citizens.…”