title: The biodrying concept: an innovative technology creating energy from sewage sludge.
abstract: A full-scale biodrying installation was treating 150 kton (wet weight) of dewatered waste activated sludge per year. The waste was treated at thermophilic conditions (65-75 °C) in a 2-step forced aeration process reducing the total wet sludge weight by 73%. The final product had a high caloric value (7700-10,400 (kJ/kg)), allowing a combustion for energy generation in external facilities. The resulting product met the European microbial and heavy metal quality standards needed for an application as organic fertilizer. The facility used <0.5 MW of electricity and recovered 9.3 MW from biologically produced heat, which was internally used for the heating of office buildings. Produced ammonia, originating from the microbial conversion of organic matter, was recovered from the ventilated air in an acid gas scrubber as an ammonium sulphate solution 40% (w/w) (7.3 kton/year) and was sold as substitute for artificial fertilizers. The sustainability of this process is discussed relative to other sludge handling processes.
authors.affiliation: GMB BioEnergie BV, P.O. Box 2, 4043 ZG Opheusden, The Netherlands; Ghent University, Department of Biosystems Engineering, Faculty of Bioscience Engineering, Coupure links 653, B-9000 Gent, Belgium. Electronic address: Mari.Winkler@ugent.be.
authors.forename: M-K H
authors.initials: MH
authors.lastname: Winkler
authors.affiliation: GMB BioEnergie BV, P.O. Box 2, 4043 ZG Opheusden, The Netherlands. Electronic address: MarcBennenbroek@gmb.eu.
authors.forename: M H
authors.initials: MH
authors.lastname: Bennenbroek
authors.affiliation: GMB BioEnergie BV, P.O. Box 2, 4043 ZG Opheusden, The Netherlands.
authors.forename: F H
authors.initials: FH
authors.lastname: Horstink
authors.affiliation: Delft University of Technology, Department of Biotechnology, Julianalaan 67, 2628 BC Delft, The Netherlands.
authors.forename: M C M
authors.initials: MCM
authors.lastname: van Loosdrecht
authors.affiliation: GMB BioEnergie BV, P.O. Box 2, 4043 ZG Opheusden, The Netherlands.
authors.forename: G-J
authors.initials: GJ
authors.lastname: van de Pol
mesh_terms: D003246:Conservation of Energy Resources; D003890:Desiccation; D006358:Hot Temperature; D009584:Nitrogen / Q000302:isolation & purification; D009812:Odorants; D012722:Sewage / Q000382:microbiology
chemical_list: D012722:Sewage; D009584:Nitrogen
keywords: Biodrying; Composting; Sludge reduction; Wastewater