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Title Processes, applications and legislative framework for carbonized anaerobic digestate: Opportunities and bottlenecks. A critical review
ID_Doc 9868
Authors Catenacci, A; Boniardi, G; Mainardis, M; Gievers, F; Farru, G; Asunis, F; Malpei, F; Goi, D; Cappai, G; Canziani, R
Title Processes, applications and legislative framework for carbonized anaerobic digestate: Opportunities and bottlenecks. A critical review
Year 2022
Published
DOI 10.1016/j.enconman.2022.115691
Abstract Char is a valuable product obtained from thermochemical conversion processes of different biomass feedstocks, mainly pyrolysis and hydrothermal carbonization (HTC). In this work, anaerobic digestion (AD) integration with pyrolysis/HTC is critically reviewed, considering anaerobic digestates as feedstocks for char production. This virtuous interconnection can boost sustainable digestate valorization in the circular economy framework. Different substrates for AD are investigated, including sewage sludge, food waste, agricultural residues, and animal manure. The available thermochemical technologies, including pyrolysis, HTC and other processes are considered, analyzing the effects of substrate characteristics and process parameters on char quality. The possible fields of char application are successively presented, including agricultural application, energy recovery, pollutants adsorption, catalysts production, and electrochemical technologies; the advantages and drawbacks of each application are highlighted. Limitations still preventing the full-scale application of digestate-derived char production and utilization include the variability in substrate characteristics and the presence of undesired pollutants (especially in sewage sludge digestate), full-scale development of thermochemical plants, lacking legislative frameworks, uncertain economic sustainability, limited eco-toxicological studies, and stakeholders' acceptance. Future research needed on the topic is finally depicted, with the aim of widening digestate reuse applications, as thermochemical processes may prevent safety concerns linked to direct agricultural reuse, leading to sustainable biorefinery platforms.
Author Keywords Char; Hydrothermal carbonization; Pyrolysis; Energy recovery; Soil application; Legislation
Index Keywords Index Keywords
Document Type Other
Open Access Open Access
Source Science Citation Index Expanded (SCI-EXPANDED)
EID WOS:000830159700001
WoS Category Thermodynamics; Energy & Fuels; Mechanics
Research Area Thermodynamics; Energy & Fuels; Mechanics
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