Circular Economy Concepts Applied to Waste Anaerobic Digestion Plants

Abstract

Anaerobic digestion contributes to the implementation of circular economy (CE) concepts. This process is assuming an increasingly important function in the treatment of the organic fraction of municipal solid waste (MSW), that is, food waste, where selective collection is optimised. The possibility of combining the recovery of matter with energy makes this approach interesting for the concepts of circular economy. Specifically, the extraction of biomethane from biogas and the following refining of the residual off-gas from impurities gives as result the extraction of CO2 that can also be used for food industry applications. A high-quality source separation of food waste gives the chance to generate a good product, compost, coherently with the aims of the circular economy principles. The use of dry processes of anaerobic digestion allows avoiding the discharge of (treated) water in the environment. Co-digestion is another option that deserves a wider adoption, because of the possibility to exploit existing volumes of digestion. This paper presents a bibliographic research based on current CE progress and MSW anaerobic digestion infrastructure in Italy and Russia. Perspectives of the sector are discussed too.

Tariff Financing of Biogas Projects at Wastewater Treatment Plants: A Comparative Study of Russian Federation

“…Anaerobic digestion is the most widely applied technique for the treatment of sewage sludge, produced at WWTPs. Anaerobic digestion is the process of microbiological decomposition of organic matter in the absence of oxygen with the release of biogas -a mixture of methane (CH4) and carbon dioxide (CO2) [24][25][26][27]. Generally, several methods of biogas energy utilization can be applied, including the combustion in boiler room, combined heat and power (CHP) generation via CHP-units and direct use as a fuel through biogas enrichment to biomethane.…”

Financial Tools for Biogas Project Implementation at Wastewater Treatment Plants: A Case Study of the Russian Federation

“…Anaerobic digestion is one of the most popular and widely spread environmental friendly techniques for various organic waste, including sewage sludge. In the absence of oxygen, the organic fraction of sewage sludge is degraded by microbes into biogas, which mainly consists of methane (CH 4 ) and carbon dioxide (CO 2 ) [15]- [18]. Biogas can be used directly in combined heat and power (CHP) units, burned to produce heat, or can be enriched and used in the same way as natural gas or as fuel for vehicles.…”

Overview of the Sustainable Valorization of Using Waste and By-Products in Grain Processing

“…The European Commission considers food waste as a priority area in order to achieve the Sustainable Development Goal target in agreement with the European Circular Economy Action Plan [14]. In addition, the European Commission amended the Waste Framework Directive 2008/98/EC, establishing as mandatory the monitoring and reporting of food waste by member states to create a baseline for monitoring the achievement of food waste reduction objectives and help identify relevant food waste streams to be utilized in a circular economy perspective [14][15][16][17]. In the European Union, the main grains processed from 2010 to 2020 were wheat, maize, rice, rye, barley, oats, and their related products.…”