Solid waste management and treatment

Transcript

1 Research activities in Environmental Technologies Solid waste management and treatment Mario Grosso The waste management team 2 full professors (M. Giugliano, S. Cernuschi) 2 researchers (, L. Rigamonti) 3 PhD students (L. Biganzoli, S. Nessi, F. Forte) 4 research collaborators Activities are carried out at the Department and at the LEAP laboratory (Piacenza), within the new MatER Research Centre 1

2 Waste treatment in Italy (historical trend) Percentage Landfill Incineration MBT Composting Energy recovery Dry fraction Campania Anaerobic digestion Recycling Waste treatment in Italy (historical trend) 6 The impressive trend of anaerobic digestion 1,4 1,2 % on total MSW 1,8,6,4,

3 Emerging issues and challenges 8 How to decrease (or at least stabilise) the waste production How to optimise material recovery (plastics being the most critical) Maximising energy recovery from residual waste combustion (combined heat and power plants feeding domestic district heating or industrial networks), according to the definitions set by the Waste Framework Directive 28/98/EC How to combine material recovery with energy recovery to improve the overall performance of waste management systems Alternative treatments for energy recovery from the residual waste Emerging role of anaerobic digestion, coupled with composting (combined energy and material recovery) How to properly assess the environmental performances of waste prevention measures The new Waste Framework Directive (28/98/EC) 9 The waste hierarchy High efficiency incineration Landfill + low efficiency incineration 3

4 The new Waste Framework Directive (28/98/EC) 1 The waste hierarchy When applying the waste hierarchy, Member States shall take measures to encourage the options that deliver the best overall environmental outcome. This may require specific waste streams departing from the hierarchy where this is justified by life-cycle thinking on the overall impacts of the generation and management of such waste. LCA applied to waste management Research activity focused on the synergic role of material and energy recovery from municipal solid waste 2. Tools: Mass and Energy balances; Life Cycle Assessment 3. Key aspects/parameters: a) Collection efficiency Type of collection b) Separation and recycling efficiency c) Management of residues from selection/recycling d) Type of substituted energy (electricity + heat) e) for materials specific mileage for waste collection 4

5 Integrated waste management scenarios: conceptual approach 29 MSW SOURCE SEPARATION Separated material MULTI-MATERIAL SEPARATION AND SELECTION OF EACH MATERIAL OFMSW Selected packaging materials Separation and selection residues Recycling residues (paper, wood and plastic) URW MBT Recycling residues (iron and aluminium) LANDFILL CEMENT KILN WTE PLANT (MASS BURN OR GASIFICATION) Slag and ash To recovery Petcoke displacement Energy: displacement of fossil fuels Iron, Aluminium Glass, Paper, Wood, Plastic OFMSW Green RECYCLING COMPOSTING ANAEROBIC DIGESTION Recycled materials: displacement of primary products Compost: displacement of peat and mineral fertilisers Compost + energy: displacement of peat and mineral fertilisers, and of fossil fuels LCA results for each collected fraction 3 Range of values of the global warming indicator for the different waste fractions (aluminum not reported, being out of scale) L. Rigamonti,, M. Giugliano (21). Journal of Cleaner Production, 18,

6 Variables which mostly affect the results of the LCA indicators 31 Sub-unit Cumulative energy demand Global warming Acidification Human toxicity Photochemical ozone creation Aluminium Selection efficiency Selection efficiency Selection efficiency Selection efficiency Selection efficiency Glass Selection efficiency Selection efficiency Selection efficiency Selection efficiency Selection efficiency Wood Energy feedstock Paper Energy feedstock Plastic Selection efficiency Selection efficiency Selection efficiency Selection efficiency Selection efficiency URW in WTE Composting Anaerobic digestion Energy recovery Avoided energy Energy feedstock Electricity consumption Energy recovery Avoided energy Process emissions Avoided product Production of biogas Production of biogas and its utilisation and its utilisation Energy recovery Avoided energy - Production of biogas and its utilisation Energy recovery Avoided energy - Energy recovery Avoided energy Production of biogas Production of biogas and its utilisation and its utilisation - L. Rigamonti,, M. Giugliano (21). Journal of Cleaner Production, 18, Focus on plastic recycling 32 Mass balance of plastic recycling L. Rigamonti, and M. Giugliano (29). Waste Management, 29,

7 Focus on plastic recycling 33 Variation of the global warming indicator for plastic recycling according to the different assumptions on selection efficiency and substitution ratio. L. Rigamonti,, M. Giugliano (21). Journal of Cleaner Production, 18, MATERIAL RECOVERY FROM BOTTOM ASHES FROM WTE PLANTS: mass balance 34 Water* 7. kg Inert materials 751. kg TREATMENT PRODUCTION OF NATURAL INERTS BA 1 kg TREATMENT Functional unit: 1 t of bottom ash Ferrous metals 78.1 kg RECYCLING Non ferrous metals 13.3 kg RECYCLING Residues 87.6 kg DISPOSAL * Preliminary ageing allows for a reduction of bottom ash humidity, from 25% to about 18% PRIMARY STEEL PRODUCTION System expansion methodology adopted: avoided products included in the analysis Attributional approach RED: burdens; GREEN: savings PRIMARY ALUMINIUM PRODUCTION 7

8 MATERIAL RECOVERY FROM BOTTOM ASHES FROM WTE PLANTS: LCA results 35 5 cementificio calcestruzzo sottofondi sottofondi concrete road 1 road 2 MJ eq. / 1 t di scorie Cumulative Energy Demand Average: MJeq./t BA recupero metalli ferrosi recupero metalli non ferrosi recupero inerte smaltimento residui trattamento scorie kg CO2 eq. / 1 t di scorie cementificio concrete calcestruzzo road sottofondi 11 road sottofondi 2 Global warming potential Average: -186 kgco 2 eq./t BA -2 recupero metalli ferrosi recupero metalli non ferrosi recupero inerte smaltimento residui trattamento scorie INTRODUCTION 36 Results of the PRIN project (27-29), funded by the Italian Ministry of University and Research: Comparative analysis of strategies for material and energy recovery from waste Technological, energetic, environmental ad economic optimisation of material and energy recovery in integrated waste management systems Working group: Politecnico di Milano Department of Energy Politecnico di Milano Department IIAR environmental section Università degli Studi di Trento Università degli Studi di Bologna Università Commerciale Luigi Bocconi (Milano) M. Giugliano, S. Cernuschi,, L. Rigamonti (211). Waste Management 8

9 Integrated waste management scenarios 37 Scenario 35% bring-up collection scheme without food waste; combination of mono- and multi-material collection Scenario 5% bring-up collection scheme without food waste; mainly mono-material collection, with maximum interception levels for all the materials Scenario 5% including food waste kerbside mono-material scheme with average interception levels Scenario 65% kerbside collection scheme, mainly mono-material, with interception levels approaching the maximum literature values Mass flow balance: results 38 DESTINATIONS OF THE MATERIAL INTERCEPTED WITH SOURCE SEPARATION (%) Source separated material Waste recycling residues WRR Scenario 35% 5% 5% including food waste 65% Selective collection (fraction other of the gross waste) Secondary material (obtained after material recovering) Waste selection residues WSR (separation multi + selection of each material) E.R L.F..2.2 MATERIAL SENT TO ENERGY RECOVERY (%) Unsorted Paper, plastic and Waste selection residual wood recycling Scenario residues WSR waste URW residues WRR-E 35% % % including food waste % Process losses during composting Total Total

10 Energy balance of Scenario 5% - no food waste 39 Life cycle assessment: results 4 Global warming 3. t CO2 eq. / year Energy recovery from the combustible residues Composting of food and green waste -9. Recycling of packaging materials Scenario 35% Scenario 5% Scenario 5% Scenario 65% including food waste Global warming results for the different scenarios Hp.: residual waste is sent to a large WTE plant producing only electricity 1

11 Life cycle assessment: results Materials collected and impacts of the different scenarios Hp.: residual waste is sent to a large WTE plant producing only electricity % t/year Scenario 35% Scenario 5% Scenario 5% including food waste Scenario 65% 41 Green waste Food waste Aluminium Metals no Al Glass Plastic Wood Paper CED GWP AP HTP POCP Indicator of best performing scenario is set to -1% Implementare la DA della FORSU in una grossa area urbana 42 OBIETTIVO Valutare dal punto di vista energetico e ambientale il ruolo della digestione anaerobica della FORSU in un contesto urbano densamente popolato e la sua sinergia con il sistema di gestione esistente. Caso di riferimento: Comune di Milano Fasi di lavoro Definizione e caratterizzazione dello scenario attuale di gestione dei rifiuti Elaborazione di scenari alternativi di gestione della FORSU Confronto tra scenari alternativi e scenario attuale mediante metodologia LCA (software SIMAPRO) Analisi di sensitività sui parametri di interesse 11

12 Implementare la DA della FORSU in una 43 grossa area urbanacostruzione DEGLI SCENARI ALTERNATIVI Ipotesi di lavoro Modalità di raccolta FORSU: porta a porta con sacchetti biodegradabili Resa di intercettazione FORSU: 6% Altre frazioni raccolte per via differenziata: % di raccolta e tipologia di trattamento invariate. Modifica composizione merceologica del RUR a termovalorizzazione. Tipologia di trattamento FORSU: digestione anaerobica + post-compostaggio Invio a termovalorizzazione degli scarti dei pretrattamenti della digestione anaerobica. Diversi utilizzi del biogas prodotto: A) cogenerazione in MCI B) combustione in caldaia ausiliaria integrata al termovalorizzatore B) upgrading e immissione in rete C) upgrading e sostituzione diesel Implementare la DA della FORSU in una grossa area urbana 44 SCENARI 1C e 1D 39% Digest. anaerobica e post compostaggio 68% Biogas 165,25 Nm 3 69% 31% Motori a comb. interna Energia termica 127,63 kwhth Energia elettrica 124,88 kwhel 61% Rete del teleriscaldamento 7% Surplus non sfruttato 14% Lavaggio amminico 11% Compressione Biometano 69,6 Nm 3 Rete nazionale 34% Digest. anaerobica e post compostaggio 59% Biogas 165,25 Nm 3 64% 36% Motori a comb. interna Energia termica 146,63 kwh th Energia elettrica 143,46 kwhel 66% Rete del teleriscaldamento 12% Surplus non sfruttato 11% Lavaggio amminico 18% Compressione Biometano 64,42 Nm 3 Autotrazione 12

13 Implementare la DA della FORSU in una 45 grossa area urbana SCENARIO VS SCENARIO 1: GWP GWP (kg CO 2 eq) Scenario Scenario 1A Scenario 1B Scenario 1C Scenario 1D Trasporti Incenerimento Compostaggio Digestione Scarti digestione Produz. sacchetti TOTALE 1A: MCI 1B: caldaia aux 1C: rete 1D: autotraz. LCA e prevenzione dei rifiuti 46 Applicazione della metodologia LCA alla valutazione delle prestazioni energetico-ambientali di 2 attività di prevenzione attuabili per ridurre i rifiuti prodotti in seguito al consumo di acqua da bere (con riferimento al contesto italiano) 1) utilizzo DELL ACQUA DI RETE PUBBLICA 2) Utilizzo di acqua confezionata in BOTTIGLIE A RENDERE (implementazione di un sistema di vuoto a rendere) in alternativa all utilizzo dell acqua confezionata in bottiglie monouso 13

14 Perché prevenzione dei rifiuti derivanti dal consumo di acqua da bere? litri/abitante/anno Primo posto in Europa per consumo pro-capite di acqua confezionata (da anni), terzo posto nel mondo % Bottiglie PET monouso Tipologia di imballaggio 18 Bottiglie vetro 3 Boccioni PET e PC+ altri imballaggi SOLO BOTTIGLIE t/anno ~ 3,4 kg/abitante/anno Risultati: indicatori di impatto 48 MJ eq./unità funzionale Cumulative energy demand (CED) PET PET 5% PLA mono PLuso mono VETRO a PET a Acqua Acqua vergine a comuso riciclato a rendere rendere sotter. dal superf. da monouso monouso postaggio incenerim. rubinetto fontanelli g Sb eq./unità funzionale PET vergine monouso Consumo di risorse abiotiche PET 5% riciclato monouso PLA mono PLuso a comuso a monopostaggio incenerim. VETRO a rendere PET a rendere Acqua Acqua sotter. dal superf. da rubinetto fontanelli kg CO2 eq./unità funzionale PET vergine monouso PET 5% riciclato monouso Riscaldamento globale PLA monouso a comuso a PLA monopostaggio incenerim VETRO a rendere PET a Acqua Acqua rendere sotter. dal superf. da rubinetto fontanelli Eutrofizzazione PET PET 5% PLA mono PLuso a comuso a rendere rendere sotter. dal superf. da mono VETRO a PET a Acqua Acqua vergine riciclato monouso monouso postaggio incenerim. rubinetto fontanelli Profili simili per CED, riscaldamento globale e consumo di risorse abiotiche Alcune differenze per quanto riguarda l indicatore di eutrofizzazione Parte punteggiata della barra relativa allo scenario che prevede l uso di acqua di rete da fontanelli pubblici = contributo del M. trasporto Grosso con auto dell acqua prelevata ai fontanelli g PO4 3 eq/unità funzionale 14

15 Two recent initiatives at POLIMI 49 Research center based in Piacenza (LEAP) SIDISA 212 Sustainable Technology for Environmental Protection International Symposium of Sanitary and Environmental Engineering, 9th Edition Milan, June 26-29, THANK YOU FOR YOUR ATTENTION! mario.grosso@polimi.it 15