Techno-economic optimization of agricultural biomass to electricity supply chain network: A case study of Tunisia

The manure biogas plant is a promising technology for the future. It represents a closed-loop system that reinforces the circular economy. However, effective and viable implementation requires optimization of the entire supply chain. In this paper, a cost optimization model for manure to electricity supply chain has been developed. The model aims to determine the best configuration for the biogas plant network (Decentralized/Centralized Biogas plant), identify the optimal locations and capacities, and give a distribution plan of materials flow within the supply chain while minimizing the overall costs. The novelty of this work consists in adopting a holistic approach that addresses a multi-region, multi-period and multi-product problem which considers seasonal variation in manure availability, different manure mixtures, the physico-chemical properties of manure and the technical aspects related to the biogas plant by adapting the open source tool OSEMOSYS. The model is applied to the Tunisian case study to provide the optimal pathway to achieve the Tunisian solar plan's target of 100MW from biogas by 2030. As a result of the optimization, the optimal network of biogas plants across 6 regions in Tunisia is identified. Our results have shown that the LCOE of generating electricity across all regions ranges between 14.2 US$ cent/kWh and 19 US$ cent/kWh. Additionally, a sensitivity analysis on two key parameters distance and capital cost is performed.