title: Case study of an MBT plant producing SRF for cement kiln co-combustion, coupled with a bioreactor landfill for process residues.
abstract: The paper describes the performances of the energy recovery pathway from the residual waste based on the production of a Solid Recovered Fuel (SRF) to be exploited via co-combustion in a cement kiln. The SRF is produced in a single stream Mechanical-Biological Treatment plant, where bio-drying of the waste is followed by mechanical refining in order to fulfil the quality requirements by the cement kilns. Peculiar of this MBT is the fact that sorting residues are disposed in a nearby landfill, managed according to a bioreactor approach, where landfill gas is collected for electric energy recovery. A detailed mass and energy balance of the system is presented based on one year operational data, followed by its Life Cycle Assessment. Results show that the system is energetically and environmentally effective, with most of the impacts being more than compensated by the savings of materials and energy. Major role in determining such outcome is the displacement of petcoke in the cement kiln, both in terms of its fossil CO2 emissions and of its life cycle impacts, including the trans-oceanic transport. To check the robustness of the results, two sensitivity analyses are performed on the landfill gas collection efficiency and on the avoided electric energy mix.
authors.affiliation: Department of Civil and Environmental Engineering, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy. Electronic address: mario.grosso@polimi.it.
authors.forename: Mario
authors.initials: M
authors.lastname: Grosso
authors.affiliation: Department of Civil and Environmental Engineering, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Dellavedova
authors.affiliation: Department of Civil and Environmental Engineering, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Rigamonti
authors.affiliation: A2A Ambiente, Cascina Darsena, I-27010 Giussago, Italy.
authors.forename: Sergio
authors.initials: S
authors.lastname: Scotti
mesh_terms: D019149:Bioreactors; D003252:Construction Materials / Q000032:analysis*; D017745:Incineration / Q000379:methods*; D062611:Solid Waste / Q000032:analysis*; D064091:Waste Disposal Facilities
chemical_list: D062611:Solid Waste
keywords: Bioreactor landfill; Cement kiln; Co-incineration; LCA; Solid recovered fuel