Valorization of digestates from urban or centralized biogas plants: a critical review

摘要: Direct landspreading of anaerobic digestates is the most common digestate management strategy. Nevertheless, post-treatment can be unavoidable, especially for environmental services providers operating large-scale digestion (AD) facilities. This review aims to assess technical feasibility achieving value-added products from urban and/or centralized AD plants (UC-AD). An exhaustive effort was dedicated identifying and clarifying available processing technologies specific issues that related UC-AD digestates. The valorization options were classified according final product destination. result a useful information source assessing pathway given local market context. Agriculture first destination considered, as it allows more direct closing nutrient carbon cycles. Several processes exist either concentrating desirable characteristics digestates, enhancing organic matter stability or producing pure reformulated fertilizers. Thermal conversion are under development full-scale demonstration. They allow valorize solids through production biofuels biochar in coming future, start whole biorefinery system. Similarly, biomass harvesting such microalgae upscaling, enabling nutrients liquid phase while producing renewable sunlight. already obtained laboratory pilot conditions example, biopesticides, biosurfactants composite materials. Adding challenges, quality variation regulation barriers, public acceptance difficult access new markets among main obstacles into products.