title: Thermal and catalytic pyrolysis of a mixture of plastics from small waste electrical and electronic equipment (WEEE).
abstract: Pyrolysis seems a promising route for recycling of heterogeneous, contaminated and additives containing plastics from waste electrical and electronic equipment (WEEE). This study deals with the thermal and catalytic pyrolysis of a synthetic mixture containing real waste plastics, representative of polymers contained in small WEEE. Two zeolite-based catalysts were used at 400°C: HUSY and HZSM-5 with a high silica content, while three different temperatures were adopted for the thermal cracking: 400, 600 and 800°C. The mass balance showed that the oil produced by pyrolysis is always the main product regardless the process conditions selected, with yields ranging from 83% to 93%. A higher yield was obtained when pyrolysis was carried out with HZSM-5 at 400°C and without catalysts, but at 600 and 800°C. Formation of a significant amount of solid residue (about 13%) is observed using HUSY. The oily liquid product of pyrolysis, analysed by GC-MS and GC-FID, as well as by elemental analysis and for energy content, appeared lighter, less viscous and with a higher concentration of monoaromatics under catalytic condition, if compared to the liquid product derived from thermal degradation at the same temperature. HZSM-5 led to the production of a high yield of styrene (17.5%), while HUSY favoured the formation of ethylbenzene (15%). Energy released by combustion of the oil was around 39MJ/kg, thus suggesting the possibility to exploit it as a fuel, if the recovery of chemical compounds could not be realised. Elemental and proximate analysis of char and GC-TCD analysis of the gas were also performed. Finally, it was estimated to what extent these two products, showing a relevant ability to release energy, could fulfil the energy demand requested in pyrolysis.
authors.affiliation: Department of Environmental Technologies, ENEA - Casaccia Research Center, Via Anguillarese 301, S. Maria di Galeria, Rome, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Santella
authors.affiliation: Department of Environmental Technologies, ENEA - Casaccia Research Center, Via Anguillarese 301, S. Maria di Galeria, Rome, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Cafiero
authors.affiliation: Department of Environmental Technologies, ENEA - Casaccia Research Center, Via Anguillarese 301, S. Maria di Galeria, Rome, Italy.
authors.forename: Doina
authors.initials: D
authors.lastname: De Angelis
authors.affiliation: Department of ICMA, Sapienza University of Rome, Via Eudossiana 18, 00184 Rome, Italy.
authors.forename: Floriana
authors.initials: F
authors.lastname: La Marca
authors.affiliation: Department of Environmental Technologies, ENEA - Casaccia Research Center, Via Anguillarese 301, S. Maria di Galeria, Rome, Italy. Electronic address: riccardo.tuffi@enea.it.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Tuffi
authors.affiliation: Department of SBAI, Sapienza University of Rome, Via del Castro Laurenziano 7, 00161 Rome, Italy. Electronic address: stefano.vecchio@uniroma1.it.
authors.forename: Stefano
authors.initials: S
authors.lastname: Vecchio Ciprioti
mesh_terms: D002384:Catalysis; D059029:Electronic Waste; D017745:Incineration / Q000379:methods*; D010969:Plastics; D059027:Recycling
chemical_list: D010969:Plastics
keywords: Catalyst; Plastic mixture; Pyrolysis; Small WEEE; Zeolite