The Challenges of Using Organic Municipal Solid Waste as Source of Secondary Raw Materials

The diversity of molecules with different functionalizations allows targeting of various end products, such as biomaterials, biobased plasticizer, food additives and fertilizer. The heterogeneity of organic municipal solid waste (OMSW) streams, however, challenges the formulation of reliable statements regarding the share of functionalized molecules. The aim of this study was the assessment of OMSW as source of functionalized molecules when hydrolysis was carried out enzymatically, thermo-chemically as well as thermo-chemically and enzymatically. Results revealed that OMSW is only quantitatively assessable at carbohydrate, protein and lipid levels. This is due to a changing seasonal and spacial composition, and consequently different hydrolytic products. However, also the treatment had an impact on the quantity. Depending on the treatment 230–640 mg g⁻¹ carbohydrates, 150–250 mg g⁻¹ lipids and 80–200 mg g⁻¹ proteins were quantified in food waste and organic street waste. The intensity of treatment had an impact on the quality of sugars. When wastes were treated enzymatically glucose, fructose and sucrose were found. Using thermochemical treatment glucose can be the only product. Contrarily, lipid and fatty acid as well as protein contents seemed not affected by the treatment.