Transforming Rural Community Economy from Linear to Circular One Using Biogas Production Technology

Twin sources - fossil fuel usage and poor waste management – that contribute to greenhouse gas emissions can be combated using the concept of circular economy through using biogas technology. This approach will allow waste conversion to meet rural energy demand and also reduce dependence on fossil fuel use. This study presents technical and business model approaches to upscale a laboratory experimental procedure for biogas production through anaerobic digestion using vegetal wastes at mesophilic temperature of 35⁰C – 40⁰C. Inoculated substrate is up-scaled using molarity concept. Waste required is 13.3 tons for 67m³ digester for 30-day hydraulic retention time to produce 39.13 m³, with daily organic loading rate is 0.44 ton of total solids. Avoided CO₂ emissions from liquefied petroleum gas, kerosene, diesel, fuel wood is 9.69kg, 37.49kg, 23.147kg, 181.65kg respectively. Total investment cost is estimated at $83,123. Life cycle cost (LCC) and return streams are estimated based on three scenarios with a 20-year life-cycle. LCC for digestate in Scenarios A and B is the same at $0.13/kg and Scenario C at $0.09/kg. For electricity generation, LCC is $0.008/kBTU and $0.01/kBTU in Scenario B and C respectively, cooking is $0.14/kg and $0.19/kg in Scenario A and C respectively. Return streams for each of the three scenarios are estimated at $116,373.36. User-centered design is used to develop the business model. The project fits well as a means to transform rural community economy from linear to circular system through producing clean and renewable energy, managing natural resources and providing jobs.