C-accounting and the role of LCA in waste management 15-06-2018 C-accounting and the role of LCA in waste management Thomas H Christensen Technical University of Denmark ICWMT Beijing, PR China October 2016 1

Use life-cycle-assessment modelling (LCA) Introduction Waste management can be described by three main challenges Controlling esthetic, hygienic and contamination risks Recovering resources: materials, energy and elements/nutrients Socio-economical acceptance Our managing approaches have over time been named by a range of concepts and slogans Waste hierarchy Cradle-to-grave, cradle-to-cradle Zero waste Green technology Sustainable technology Circular economy Today’s presentation: Environmental quantification 3 take-home-messages: Quantification of climate change impacts: C-accounting System approach Move from single value quantification to distributions Use life-cycle-assessment modelling (LCA)

Quantification of impacts C-accounting/climate change Environmental impacts are many: Climate Change Eutrophication (freshwater, marine, terrestrial) Acidification Human Toxicity (carcinogenic, non-carcinogenic) Ecotoxicity Particulate Matter (air) Resource Depletion (fossil, abiotic)

Quantification of impacts C-accounting/climate change Environmental impacts are many: Climate Change Eutrophication (freshwater, marine, terrestrial) Acidification Human Toxicity (carcinogenic, non-carcinogenic) Ecotoxicity Particulate Matter (air) Resource Depletion (fossil, abiotic) In general: For bulk waste: MSW, demolition waste, agricultural waste etc: Climate change is important For specific/hazardous waste: WEEE, shredder waste etc: Toxicity is important

Quantification of impacts C-accounting/climate change For waste management we cannot directly use the approach of IPCC Environmental impacts are many: Climate Change Eutrophication (freshwater, marine, terrestrial) Acidification Human Toxicity (carcinogenic, non-carcinogenic) Ecotoxicity Particulate Matter (air) Resource Depletion (fossil, abiotic) In general: For bulk waste: MSW, demolition waste, agricultural waste etc: Climate change is important For specific/hazardous waste. WEEE, shredder waste etc: Toxicity is important

The waste management system Load to the environment Mass balances Energy budget Emission account emissions emissions emissions materiale Materiales and energy can substitute for other production of materials and energy waste materiale waste materiale waste energy Saving to the environment materiale energy

The system approach has go beyond the waste management system emissions emissions emissions materiale Materiales and energy can substitute for other production of materials and energy waste materiale waste materiale waste energy materiale energy

Characterization Factors 15-06-2018 Characterization Factors C counting as GHG: Consider changes caused by waste management: Biogenic CO2 is neutral C-fossil emitted as CO2: GWP = 1 Kg CO2-eqivalents/ kg CO2 C-fossil bound: GWP = 0 C-biogenic emitted as CO2: GWP = 0 C-biogenic bound: - 3.67 Kg CO2-eqivalents/ kg C bound (after 100 years) avoided C-fossil emitted as CO2: GWP = -1 Kg CO2-eqivalents/kg CO2 avoided C-biogenic emitted as CO2: GWP = 0 release of bound C-biogenic: 3.67 Kg CO2-eqivalents/ kg C released C emitted as methane: 28 kg CO2-equivalents/ kg CH4 (100 years)

Characterization Factors 15-06-2018 Characterization Factors C counting as GHG: Consider changes caused by waste management: Biogenic CO2 is neutral C-fossil emitted as CO2: GWP = 1 Kg CO2-eqivalents/ kg CO2 C-fossil bound: GWP = 0 C-biogenic emitted as CO2: GWP = 0 C-biogenic bound: - 3.67 Kg CO2-eqivalents/ kg C bound avoided C-fossil emitted as CO2: GWP = -1 Kg CO2-eqivalents/kg CO2 avoided C-biogenic emitted as CO2: GWP = 0 release of bound C-biogenic: 3.67 Kg CO2-eqivalents/ kg C released C emitted as methane: 28 kg CO2-equivalents/ kg CH4 (100 years)

Mass balance of landfill: 100 years 15-06-2018 Biogenic C Mass balance of landfill: 100 years Depends on the degradation k Manfredi,S. & Christensen,T.H. (2009): Environmental assessment of solid waste landfilling technologies by means of LCA-modeling. Waste Management, 29, 32-43.

System approach We need to include the upstream (energy and materials used) and the downstream (savings by recycling and use of recovered energy) activities in our quantitative model for GHG accounting Usually a range of technologies are needed to achieve recovery of materials, energy and elements/nutrients Waste is a heterogeneous material and most single technologies have rejects/residues that need other treatment A simple system may look like

Plastic recycling: mechanical treatment of source separated mixed plastic

Mass balance of plastic sorting and recyling 19% plastic in the MSW Plastic and others in MSW kg associated with 1000 kg MSW plastic waste Source separation efficiency MRF transfer-coefficients PET HDPE POF mix Plasmix Iron Aluminium Bottles, plastic 270 80% 216 kg 70% 151 kg 20% 43 kg - 10% 22 kg Soft plastic 360 50% 180 kg 144 kg 36 kg Hard plastic 110 55 kg 51% 28 kg 31% 17 kg 18% 10 kg Non-re-plastic 260 130 kg 100% Total plastic (kg) 1000 581 151 71 161 198 Paper 2400 1.5% 35 kg Wood 300 3.3% Textile Iron, cans 225 14% 32 kg 53% 47% 15 kg 75 13% 7 kg 30% 3 kg Inert (Glass) 900 8% 70 kg Total (kg) 5200 748 347 15 3 Plastic recycling Down-cycling Reject/ fuel Metal recycling

LCA- modelling is the systematic approach Example of output in terms of CO2-equi. /ton MSW Incineration Plastic recycling RDF in cement kiln Metal recycling Glass recycling Paper recycling Collection and transport Anaerobic digestion Plastic in cement kiln

Food waste and other bioresidues for green energy Alternative uses Land-use-change Fodder production Not single values but intervals/ average plus 95% confidence Use of a consequential approach Tonini, D. et. 2016 Technical Univ. of Denmark

Moving to distributed results Variation in results can be of different nature Modeling approach Scenario setting Parameter values One approach: Parameterize all values and choices in the model Estimate the distribution of each parameter Run Monte Carlo simulations

A shortcut for determining uncertainty Simple calculation of sensitivity ratio The variation around the average result can be calculated analytically with Global Sensitivity Analysis For each model parameter: The total scenario uncertainty can be obtained summing the contribution to uncertainty of each parameter Same as input to Monte Carlo!

Few parameters describe the uncertainty Identification of IMPORTANT parameters Uncertainty output= Σ (Uncertainty priority) + Σ (Uncertainty remaining) Bisinella, V., Conradsen, K., Christensen, T.H., Astrup, T.F. (2016). A global approach for sparse representation of uncertainty in Life Cycle Assessments of waste management systems. Int. J. Life Cycle Assess. 21, 378–394.

Thank you fro your attention 15-06-2018 Conclusion Use LCA to understand your waste management system It provides a stringent understanding of your system It provides transparency as to what matters Use a system approach Include those parts outside the waste management system The savings usually take place outside our system, but are still important The context defines the system No single value results in the future –hopefully Accept that results are uncertain Provide quantification of uncertainty Simplified methods are available targeting your data collection In C-accounting Use consistent characterization factors also those you do not like Thank you fro your attention