Location analysis for optimal collection of perennial forage crops to a biogas plant : the case of ley crops in Uppsala, Sweden

Abstract: Purpose: This study uses a location analysis technique to evaluate the optimal location of a biogas plant site primarily by optimizing the collection and transport of a mix of perennial forage crops (ley crops) for the production of biogas in Uppsala municipality. Content: Ley crops together with organic waste from households and restaurants are used as substrates for biogas production in Västerås municipality in the county of Västmanland. The biogas plant in Västerås consist of a 4000m3 digester tank, which is fed with a yearly total amount of 14000 tonnes of source-sorted food waste from households, 5000 tonnes of ley crops, and 2000 tonnes of sludge from grease separators. Previous studies have investigated the performance optimization of the biogas plant. It was found that the plant operates very well at full-scale and a feasible performance improvement of the biogas system was examined. In the case of Uppsala, a municipality in east central Sweden, ley crops in the region are currently not used for biogas production, but are used for the production of animal feeds instead. 5000 tonnes of ley crops make up less than 1% of the total ley produced in Uppsala County. This study uses a GIS-based approach (ArcGIS Network Analyst tool for the closest facility and the Load-Distance (LD) technique) to optimise the logistics of collecting and transporting an annual amount of 5000 tonnes of ley crops as a substrate for biogas production in Uppsala municipality using a feedstock ratio and digester volume similar to the existing biogas plant in Västerås and then deciding the optimal location for a biogas plant. Results: Data from 2014 are used in this study and the results reveal that the location proposed for candidate biogas plant site-2 in scenario 3 (70% of land use) is the best location.