Feasibility Analysis on the Adoption of Decentralized Anaerobic Co-Digestion for the Treatment of Municipal Organic Waste with Energy Recovery in Urban Districts of Metropolitan Areas

Abstract

Anaerobic digestion (AD) of organic fraction of municipal solid waste (OFMSW) is considered an excellent solution for both waste management and energy generation, although the impacts of waste collection and transportation on the whole management system are not negligible. AD is often regarded as a centralized solution for an entire community, although recently, there has been some debate on the adoption of decentralized, smaller facilities. This study aims to evaluate the techno-economic feasibility of an AD plant at the local scale for the treatment of organic waste generated from urban districts. Depending on the type of feedstock, two scenarios were evaluated and compared with the reference scenario, based on composting treatment: (1) mono-AD of OFMSW and (2) co-AD of OFMSW and sewage sludge (SS). Furthermore, different district extensions of the metropolitan area were considered with the goal of determining the optimal size. Results showed the advantage of the two scenarios over the reference one. Scenario 1 proved to be the most suitable solution, because the introduction of SS in Scenario 2 increased costs and payback time, rather than generating a higher waste amount and lower biogas yield. The preferred district extension was the medium-sized one. Capital cost strongly affected the economic analysis, but revenue from the city for the management operation of the organic waste could significantly decrease costs. Further studies about the differences in the type of feedstock or the introduction of other criteria of analysis (such as environmental) are considered necessary.

Evolution of the Olive Oil Industry along the Entire Production Chain and Related Waste Management

“…AD involves high investment costs and is economically inapplicable when the plant's potential is less than a few tens of thousands of tons per year [91,100,101]. Waste from oil mills can be treated with this technology only if added in a limited percentage (10-20%) to different substrates for which AD is the preferred solution [102,103].…”

Review of waste phosphorus from aquaculture: Source, removal and recovery

“…319 AD is a multistage process that includes hydrolysis, fermentation, acetogenesis and methanogenesis. 320,321 Cell decay and release of P usually induce a high P level in AD effluents. Struvite and hydroxyapatite (HAP) can trap P in AD effluents and sludge, both of which can be utilized as slow-release P fertilizers.…”

“…Anaerobic digestion (AD) refers to the process carried out by facultative and anaerobic bacteria to degrade organic matter into methane (CH 4 ), CO 2 , hydrogen sulfide (H 2 S) and water under anaerobic conditions 319 . AD is a multistage process that includes hydrolysis, fermentation, acetogenesis and methanogenesis 320,321 . Cell decay and release of P usually induce a high P level in AD effluents.…”

Renewable energy generating technologies from solid waste improve urban waste management system in Asella town, Arsi zone, Oromia regional state, Ethiopia

“…Recycling and reusing are technical options for the reduction of solid waste. Composting and anaerobic digestions were also other technological options for the treatment of organic fractions of solid wastes (Gadaleta, De Gisi et al 2021). Waste-to-energy transformation technology is a strategy for solid waste management in addition to the production of energy from discarded solid waste items.…”