The global transition toward sustainable energy systems has elevated biogas as a renewable alternative capable of addressing both energy poverty and environmental degradation. This study examines decentralized biogas production systems utilizing organic waste streams - including agricultural residues (35% yield potential), food waste (28% volatile solids), and municipal sewage - to achieve dual objectives of energy generation and waste valorization. Our environmental analysis reveals these systems reduce greenhouse gas emissions by 62% compared to conventional fossil fuels through methane capture and organic matter diversion from landfills. Energy savings are achieved via three mechanisms: (1) direct combustion of biogas yielding 22-28 MJ/m³ thermal energy, (2) electricity generation at 2.1 kWh/m³ conversion efficiency, and (3) waste heat recovery from cogeneration systems (75% total efficiency). The carbon footprint assessment demonstrates 0.45 kg CO₂eq/kWh compared to 0.98 kg CO₂eq/kWh for grid electricity in the studied region. A 36-month case study of Abu Saleem Municipality analyzed 120,000 metric tons of processed waste, showing 43% (51,600 tons) was suitable for anaerobic digestion, producing 7.2 million m³ biogas annually - equivalent to replacing 1,850 tons of diesel fuel. The remaining 57% non-digestible material was successfully repurposed in construction applications (32%) and recycling programs (25%), achieving 89% total waste diversion from landfills. These systems demonstrate compelling sustainability metrics: 1:3.8 energy return on investment (EROI), 40% reduction in local particulate emissions, and 22% decrease in agricultural runoff pollution when digestate replaces chemical fertilizers. The model presents a scalable template for communities seeking energy independence while addressing waste management challenges and climate commitments through circular economic principles.
Agll et al. (Sun,) studied this question.