Strategies to Optimize the Energetic and Material Utilization of the Organic Fraction of Municipal Solid Waste by Considering the Entire Value Chain

The organic fraction of municipal solid waste (OFMSW) is a valuable resource for a bioeconomy and its current treatment based on the combination of anaerobic digestion (AD) and composting is the best existing state-of-the-art utilization that already represents a circular approach. The existing OFMSW value chain, however, needs to be optimized for a best-possible bioeconomy, especially with regard to collected waste volumes, achieved energy yields or product qualities. Furthermore, alternative technologies to supplement the existing AD and composting concepts should be discussed. Several strategies to optimize the energetic and material utilization of OFMSW can be addressed through knowledge on OFMSW properties or by considering the entire value chain from waste production and collection to utilization and recycling. The following aspects are presented within this doctoral thesis: 1) OFMSW production: a comprehensive physico-chemical characterization of German OFMSW samples originating from a consistent collection area depending on season and settlement structure 2) OFMSW collection and logistics: monitoring of storage processes to determine their influence on material properties of OFMSW depending on storage temperature and condition 3a) OFMSW utilization in AD: energy potentials of OFMSW in co-digestion with digested sewage sludge (DSS) depending on the defined process temperature in AD 3b) OFMSW utilization in AD: energy potentials of OFMSW in co-digestion with DSS and wood ashes depending on different mixing ratios for nutrient supply This thesis mainly presents suggestions for improvements of the current OFMSW value chain but also discusses future treatment concepts.