Ecological and economical optima of material recycling - - PowerPoint PPT Presentation

Ecological and economical

• ptima of material

recycling

Presentation at the 3rd International Conference

• n Life Cycle Management

Zurich, August 27–29, 2007

Doka Life Cycle Assessments, Zurich

lcm07 {at} doka.ch

Buero fuer Analyse und Oekologie BAO, Zurich

patrick_hofstetter {at} yahoo.com

By Gabor Doka & Patrick Hofstetter

Project funded by BAFU Bundesamt Fuer Umwelt (Swiss EPA)

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Contents

• 1. Approach to assess recycling systems in LCI
• 2. LCIA methods, Monetarisation & Hidden Costs
• 3. Case Study: Galvanising Sludge Recycling

3 Doka Life Cycle Assessments, Zurich Buero fuer Analyse & Oekologie, Zürich

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“

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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 (–) .

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Disposal Function 1 kg Supply Function x kg

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: Recycling process Waste Recyclate Landfill Waste

Option Recycling Option Unrecycling

Primary production Product

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Disposal Function 1 kg Supply Function x kg

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: Collection of functions, that both

• ptions must provide:

Utility Basket

This is System Expansion+

+ISO unfortunately calls Substitution (–) also

System Expansion

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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)

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Simple Monetarisation

Damage cost data

Based on...

References

...CO2

Krewitt; Downing; Watkiss; Stern Rabl; Krewitt; Spadaro Hofstetter & Müller-Wenk; Rabl; ARE Ott

...PM10 ... DALYs ... Ext. Cost Study Switzerland

Unit

Low Medium Large

CHF/kg CHF/kg CHF/DALY CHF/yr

1.0E10 1.6E10 2.16E10 0.45 0.11 0.024 19 100 260’000 90’000 Various external cost studies:

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Simple Monetarisation

Total LCIA burden [points] Total external environmental LC-costs [CHF] · K [CHF/point] = Obtain Monetarisation by direct proportionality to LCIA scores: CHF2005 per Eco-indicator‘99(HA)-point Based on... Low K Medium K Large K ...CO2 4.4 20.2 82.6 ...PM10 2.0 10.3 ...DALYs 3.5 10.0 ....Ext. Cost Study CH 1.8 (rev. 5.6) 2.9 (rev. 8.6) 3.9 (rev. 11.6) This study 3.5 10 40

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Simple Monetarisation

And for the ecoscarcity methods per 1000 UBP-points

CHF per 1000 UBP‘97-points CHF per 1000 UBP‘06-points Low 0.12 0.17 0.15 0.15 Medium Large 0.55 0.91 0.24 0.55 2.25 0.32 1 Based on... Low Medium Large ...CO2 0.08 0.35 1.45 ...PM10 0.13 0.67 ... Ext. Cost Study CH 0.07 0.11 0.15 This study 0.1 0.35 0.7

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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.

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Environmental damage costs Environmental damage costs

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Case Study: Galvanising sludge

Galvanising sludge from electroplating operations Sludge E.g. copper plating

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Case Study: Galvanising sludge

Disposal options for galvanising sludge Salt mine storage Landfill

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Case Study: Galvanising sludge

...or recycling in metal smelters

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Process galvanising sludge recycling

Galvanising Sludge Secondary Zinc

Slags

Electrolysis Pb-Smelter Secondary Lead Lead-rich dust Disposal Function 1kg sludge Supply Functions 10 g Pb 130 g Zn

Drying, transport

Zn-Smelter

Energy, materials Waste-specific emissions

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Sludge Recycling vs. Unrecycling

Landfill Sludge

Option Recycling Option Unrecycling

10 g Pb 130 g Zn Recycling process Sludge Recyclates Primary Zn 130 g Zn Primary Pb 10 g Pb

Flows not in proportional size

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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

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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.

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Tailings

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)

Example tailings dump site

~1km

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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.

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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

50‘000

Recycling Unrecycling Ecoscarcity 97 points Sludge in smelters Sludge in landfill Malus for zinc Malus for other not directly fulfilled functions*

* mainly from lost copper

→ Lots of room for improvement also for the recycling option

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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.

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Monetarisation Results

• Damage costs for

Option Recycling are several thousand CHF per ton lower than for Option Unrecycling

• Where promotion of

recycling is necessary, very large subsidises for recycling (or penalties for unrecycling) can be justified.

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Conclusions

• Utility Basket: A simple, transparent approach to assess various

disposal options

• Environmental costs directly from single-score LCIA methods
• Environmental costs usually dominate hidden costs
• Environmental costs are very large compared to market prices
• Current LCI of primary metal production is still incomplete: major

burdens yet to be added (esp. long-term effects of tailings and mine drainage)

• This affects primary production, and thus usually favours recycling

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Thank you for your attention

Disposal in Beijing