Biomass to bioenergy value-chain and optimizing costs of transportation network

Background and Purpose: Lignocellulosic biomass, a promising renewable resource, has gained attraction as a potential alternative for biofuel production and climate change mitigation. Agricultural practices often generate significant quantities of lignocellulosic residues (e.g., crop stalks), which are frequently abandoned or burned, leading to adverse environmental impacts. Wisely collection and conversion of these residues into bioenergy could offer a twofold benefit: reducing environmental harm and partially displacing fossil fuels. The study aimed at evaluating the potential of lignocellulosic biomass from agricultural activities in Golestān province as a sustainable source for renewable energy production; and estimating the transportation costs associated with the biomass feedstock within the context of a pilot project.
Materials and methods: To do so, we employed satellite image processing (Sentinel-2 and Landsat 8) to generate land-use maps and identify the spatial distribution of biomass supply sources from four major crops (wheat, soybean, rice, and rapeseed) and estimate the available biomass volume from each crop in energy units (kWh). Subsequently, an optimization model was developed to design a biomass-to-energy supply chain network for the study area.
Results: The overall classification accuracy and kappa coefficient for wheat and rapeseed using Sentinel images were 82% and 0.74, respectively. Soybean and rice classifications using Landsat images achieved 76% and 0.63 accuracy, respectively. Area estimation identified 84,104 farms exceeding 2 ha, encompassing a total area of 468,000 ha. This represents an 11% bias compared to statistics provided by the Iran's Ministry of Agriculture organization for the same period. The optimistic scenario suggests a potential harvest of 3.8 million kWh of energy from the identified farms. The optimization model, considering both fixed and variable transportation costs, determined that locating three biorefineries would be sufficient to process the biomass and generate electricity. Transportation costs for this scenario were: US$222 million fixed cost, US$1.599 billion variable cost, and a total cost of US$1.821 billion. The optimal scenario also minimized transportation distances, with a maximum on-site distance of 81 km and an average distance of 27 km. These distances represent a significant reduction compared to single-site (74% decrease) and two-site (34% decrease) scenarios.
Conclusions: The results highlight the potential of utilizing agricultural biomass for biofuel production in Golestān province. Developing a diversified energy portfolio that reduces dependence on fossil fuels and mitigates their environmental impacts necessitates further research in this area.The results highlight the potential of utilizing agricultural biomass for biofuel production in Golestān province. Developing a diversified energy portfolio that reduces dependence on fossil fuels and mitigates their environmental impacts necessitates further research in this area.