Ecological and economical optima of material recycling Presentation at the 3rd International Conference on Life Cycle Management Zurich, August 27–29, 2007 By Gabor Doka & Patrick Hofstetter Doka Life Cycle Buero fuer Analyse Assessments, Zurich und Oekologie BAO, Zurich lcm07 {at} doka.ch patrick_hofstetter {at} yahoo.com Project funded by BAFU Bundesamt Fuer Umwelt (Swiss EPA)
Contents 1. Approach to assess recycling systems in LCI 2. LCIA methods, Monetarisation & Hidden Costs 3. Case Study: Galvanising Sludge Recycling Doka Life Cycle Assessments, Zurich Buero fuer Analyse & Oekologie, Zürich 2
Goal Compare recycling systems with established waste disposal Is recycling beneficial? When is recycling beneficial? Which coherent approach can assess various recycling schemes for different waste materials? Project funded by BAFU (Swiss EPA, Bundesamt fuer Umwelt) “Erweiterung der Ökobilanzmethodik für verbesserte Modellierung einer Kreislaufwirtschaft“ Doka Life Cycle Assessments, Zurich Buero fuer Analyse & Oekologie, Zürich 3
Approach System Boundaries Recycling processes generally have two functions: (1) to dispose of waste and (2) to produce secondary materials Multi-functional process (disposal and supply) Often in LCA we are only interested in one of these functions: E.g. Cement kilns fired with waste oil or other secondary fuels. Which burdens are attributable to the cement product? E.g. Plastic beverage packaging recycled as fleece textiles. Which burdens are attributable to the beverage packing disposal? Usually solved with Allocation (÷) or Substitution (–) . Doka Life Cycle Assessments, Zurich Buero fuer Analyse & Oekologie, Zürich 4
Approach System Boundaries BUT: To compare recycling processes with other options it is not necessary to isolate the disposal and supply functions of recycling. Make sure that both options fulfil the same range of functions: Option Recycling Option Unrecycling Waste Waste Disposal Function Landfill 1 kg Recycling process Primary production Supply Function Recyclate x kg Product Doka Life Cycle Assessments, Zurich Buero fuer Analyse & Oekologie, Zürich 5
Approach System Boundaries BUT: To compare recycling processes with other options it is not necessary to isolate the disposal and supply functions of recycling. Make sure that both options fulfil the same range of functions: Disposal Collection of functions, that both Function options must provide: 1 kg Utility Basket This is System Expansion + Supply Function + ISO unfortunately calls Substitution (–) also x kg System Expansion Doka Life Cycle Assessments, Zurich Buero fuer Analyse & Oekologie, Zürich 6
Life Cycle Impact Assessment We used existing LCIA methods: Eco-indicator’99 • Swiss ecoscarcity method 97 (BUWAL-method, UBP’97) • Update Swiss ecoscarcity 06 (Draft Version, UBP’06) • New, simple Monetarisation Approach (Patrick Hofstetter) By direct proportionality to LCIA scores. • Based on ‘willingness to accept’-approach • (estimated compensation to accept an inflicted damage) In Swiss Francs 2005 (CHF) • Doka Life Cycle Assessments, Zurich Buero fuer Analyse & Oekologie, Zürich 7
Simple Monetarisation Various external cost studies: Damage cost data Based on... Low Medium Large References Unit Krewitt; ...CO 2 0.024 0.11 0.45 Downing; CHF/kg Watkiss; Stern Rabl; Krewitt; ...PM 10 19 100 CHF/kg Spadaro Hofstetter & ... DALYs 90’000 260’000 Müller-Wenk; CHF/DALY Rabl; ARE ... Ext. Cost Study 1.0E10 1.6E10 2.16E10 Ott CHF/yr Switzerland Doka Life Cycle Assessments, Zurich Buero fuer Analyse & Oekologie, Zürich 8
Simple Monetarisation Obtain Monetarisation by direct proportionality to LCIA scores: Total LCIA burden Total external environmental · K [CHF/point] = [points] LC-costs [CHF] CHF 2005 per Eco-indicator‘99(HA)-point Based on... Low K Medium K Large K ...CO 2 4.4 20.2 82.6 ...PM 10 2.0 10.3 ...DALYs 3.5 10.0 1.8 2.9 3.9 ....Ext. Cost Study CH (rev. 5.6) (rev. 8.6) (rev. 11.6) This study 3.5 10 40 Doka Life Cycle Assessments, Zurich Buero fuer Analyse & Oekologie, Zürich 9
Simple Monetarisation And for the ecoscarcity methods per 1000 UBP-points CHF per 1000 UBP‘97-points CHF per 1000 UBP‘06-points Based on... Low Medium Large Low Medium Large ...CO 2 0.12 0.55 2.25 0.08 0.35 1.45 ...PM 10 0.17 0.91 0.13 0.67 ... Ext. Cost 0.15 0.24 0.32 0.07 0.11 0.15 Study CH This study 0.15 0.55 1 0.1 0.35 0.7 Doka Life Cycle Assessments, Zurich Buero fuer Analyse & Oekologie, Zürich 10
Other Hidden Costs Environmental damage costs are not the only external costs, e.g.: Resource production subsidises • Military expenses for resource production security • Lower environmental standards in developing countries • Closure and renaturation of mines • Missing worker’s health and accident risks compensation • Effects of deteriorating resource grades • Work in progress Preliminary conclusion: With the exception of oil, environmental damage costs dominate the total external costs caused by resource extraction and production. Doka Life Cycle Assessments, Zurich Buero fuer Analyse & Oekologie, Zürich 11
Buero fuer Analyse & Oekologie, Zürich Environmental damage costs Environmental damage costs 12 Doka Life Cycle Assessments, Zurich
Case Study: Galvanising sludge Galvanising sludge from electroplating operations E.g. copper plating Sludge Doka Life Cycle Assessments, Zurich Buero fuer Analyse & Oekologie, Zürich 13
Landfill Buero fuer Analyse & Oekologie, Zürich Case Study: Galvanising sludge 14 Doka Life Cycle Assessments, Zurich Disposal options for galvanising sludge Salt mine storage
Buero fuer Analyse & Oekologie, Zürich Case Study: Galvanising sludge 15 ...or recycling in metal smelters Doka Life Cycle Assessments, Zurich
Process galvanising sludge recycling Disposal Function Galvanising Sludge 1kg sludge Drying, transport Energy, materials Waste-specific emissions Zn-Smelter Slags Lead-rich dust Electrolysis Pb-Smelter Secondary Zinc Secondary Lead Supply 130 g Zn 10 g Pb Functions Doka Life Cycle Assessments, Zurich Buero fuer Analyse & Oekologie, Zürich 16
Sludge Recycling vs. Unrecycling Option Recycling Option Unrecycling Sludge Sludge Landfill Recycling process Primary Zn Primary Pb Recyclates 130 g Zn 130 g Zn 10 g Pb 10 g Pb Flows not in proportional size Doka Life Cycle Assessments, Zurich Buero fuer Analyse & Oekologie, Zürich 17
Utility basket for sludge disposal 1 kg sludge disposal + 130 g of zinc + 10 g of lead Based on the sludge composition and recycling processes additional functions and/or different amounts can result. If any of the options cannot fulfil the whole basket, reference processes can be added as complement = demerit or malus for lost opportunities Doka Life Cycle Assessments, Zurich Buero fuer Analyse & Oekologie, Zürich 18
Primary production The primary production processes are essential in assessing the • suitability of recycling schemes. • LCI of metals is still patchy. LCI databases, like ecoinvent, have but coarse LCI of metals. • E.g. tailings: large volume, metal-bearing waste from metal ore beneficiation • Problems with metal leaching, acidification of leachate (acid rock drainage ARD) Long-term legacy of mining sites. • E.g. 12 kg tailings per kg zinc, 350 kg tailings per kg copper Important for a complete LCA of primary metal production. • Doka Life Cycle Assessments, Zurich Buero fuer Analyse & Oekologie, Zürich 19
Example tailings dump site Tailings ~1km Global annual production of tailings: Several hundred million tons (Jakubick & McKenna 2003) Tailings and other mining waste production is larger than the amounts moved annually by natural erosion (Gardner & Sampat 1998) Doka Life Cycle Assessments, Zurich Buero fuer Analyse & Oekologie, Zürich 20
Tailings disposal Preliminary model for emissions from tailings dump sites created for this study. In analogy to landfill models used in ecoinvent database (Doka G. (2003) Life Cycle Inventories of Waste Treatment Services. ecoinvent 2000 report No. 13. EMPA St. Gallen, Swiss Centre for Life Cycle Inventories, Dübendorf, CH) Burdens from tailings make up 0.5%–60% of the burden of primary zinc, copper, nickel, or lead, depending in the LCIA method. Doka Life Cycle Assessments, Zurich Buero fuer Analyse & Oekologie, Zürich 21
Results galvanising sludge diposal Utility basket = 1 kg disposal + 138g Zn + 9.4 g Pb + 3.4 g Ni + 3.5 g Cu + 560 g abrasive mineral Sludge in smelters Ecoscarcity 97 points Sludge in landfill 50‘000 Malus for zinc Malus for other not directly fulfilled functions* * mainly from lost copper → Lots of room for 0 improvement also for the Recycling Unrecycling recycling option Doka Life Cycle Assessments, Zurich Buero fuer Analyse & Oekologie, Zürich 22
Results galvanising sludge diposal Is there a threshold, where recycling is not sensible anymore? Results for galvanising sludge with variable zinc content (x-axis) Typical result Similar also for other LCIA- methods and other metals. Doka Life Cycle Assessments, Zurich Buero fuer Analyse & Oekologie, Zürich 23
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