title: Sewage sludge drying by energy recovery from OFMSW composting: preliminary feasibility evaluation.
abstract: In this paper an original energy recovery method from composting is analyzed. The integrated system exploits the heat available from the aerobic biochemical process in order to support the drying of sewage sludge, using a specific solar greenhouse. The aim is to tackle the problem of organic waste treatment, with specific regard to food waste. This is done by optimizing the energy consumption of the aerobic process of composting, using the heat produced to solve a second important waste management problem such as the sewage waste treatment. Energy and mass balances are presented in a preliminary feasibility study. Referring to a composting plant with a capacity of 15,000 t/y of food waste, the estimation of the power from recovered heat for the entire plant resulted about 42 kW. The results demonstrated that the energy recoverable can cover part of the heat necessary for the treatment of sludge generated by the population served by the composting plant (in terms of food waste and green waste collection). The addition of a renewable source such as solar energy could cover the residual energy demand. The approach is presented in detail in order for it to be replicated in other case studies or at full scale applications.
authors.affiliation: University of Trento, Department of Civil, Environmental and Mechanical Engineering, via Mesiano 77, I-38123 Trento, Italy.
authors.forename: Elena Cristina
authors.initials: EC
authors.lastname: Rada
authors.affiliation: University of Trento, Department of Civil, Environmental and Mechanical Engineering, via Mesiano 77, I-38123 Trento, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Ragazzi
authors.affiliation: University of Trento, Department of Civil, Environmental and Mechanical Engineering, via Mesiano 77, I-38123 Trento, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Villotti
authors.affiliation: Insubria University of Varese, Department of Biotechnologies and Life Sciences, Via G.B. Vico 46, I-21100 Varese, Italy. Electronic address: vincenzo.torretta@uninsubria.it.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Torretta
mesh_terms: D003247:Conservation of Natural Resources; D003890:Desiccation; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D012722:Sewage
keywords: Composting; Drying of sewage sludge; Energy recovery; Greenhouse; Heat recovery