1. Issues in Inventory Analysis Even though the methodology of inventory analysis seems relatively straightforward, it is – in fact – complicated by two important issues: Defining boundaries for the system under analysis: Which processes to include and which to exclude? Defining boundaries for the system under analysis: Which processes to include and which to exclude? Allocation of elementary flows if the process has more than one economic output: Allocation of elementary flows if the process has more than one economic output: unit process materials energy wastes emissions product Aproduct B

2. Allocation Consoli et al, (1993) identify 3 types of processes where allocation is necessary: co-production, waste treatment, recycling and reuse in an open loop. A hierarchy of preferred approaches has been defined in ISO14044, Section 4.3.4: 1. Avoiding allocation by dividing the unit process 2. Avoiding allocation by system expansion 3. Allocation on the basis of physical relationship 4. Allocation on the basis of other relationship, i.e. economic value unit process materials energy wastes emissions product Aproduct B unit process materials energy wastes emissions waste Awaste B Life Cycle B Life Cycle A closed loop open loop

3. Avoiding allocation by dividing the unit process materials & energy wastes & emissions product A product B Sub- process A Sub- process B Problems: - It may not be possible, realistic or desirable to run sub-processes independently - Many processes are inherently multi-functional (e.g. separation processes) The unit process to be allocated is divided into sub-processes and data are collected separately for these sub-processes. Multi-function process M

4. Avoiding allocation by system expansion The system is expanded to include the co-products in the reference flow (i.e. additional functions in the Functional Unit - FU). Problems: - Usually means that more processes need to be included in the LCI - More complex FUs makes comparison of different product systems more difficult co-producing process a primary product A process b intermediate process i Boundaries of original system co-product C product B Boundaries of expanded system Reference flow: A + B Elementary flows: E a + E i + E b Reference flow: A + C Elementary flows: E a + E i Boundaries of expanded system

5. Allocation on the basis of underlying physical relationship Problems: - Ignores relationship between co-products A and B - Assumes linear relationship between environmental interventions and product outputs - Ignores the downstream impacts of the excluded co-product unit process Emissions E(A,B) product Aproduct B allocated process product A allocated process product B The environmental interventions are partitioned between the co-products in a way that reflects the physical relationship between products and interventions. Emissions αE Emissions (1-α)E

6. Allocation on the basis of mass relationship unit process 20 kg product A80 kg product B allocated process 20 kg product A allocated process 80 kg product B Example: Emissions 0.2 kg Emissions 0.8 kg Emissions 1 kg On a mass basis, product A is allocated 20% of the emissions.

7. Allocation on the basis of economic relationship unit process 20 kg product A $900 80 kg product B $100 allocated process 20 kg product A $900 allocated process 80 kg product B $100 Example: Emissions 0.9 kg Emissions 0.1 kg Emissions 1 kg On an economic basis, product A is allocated 90% of the emissions.

8. Chlor-Alkali Electrolysis 1 ton of chlorine ($90) 1.1 tons of caustic soda ($262) 0.28 tons of hydrogen ($10) 1.7 tons of salt 3.8 MWh of electricity Example of Co-production

9. The system is expanded to include additional burdens of co-product processing and the avoided burdens of any avoided processes Vehicle production v Vehicle Primary production p Building production b Recycling process r E v + E r – E p Vehicle life cycle Building life cycle Building Environmental burdens of the vehicle: Allocation by system expansion (avoided burden approach) scrap

10. A closer look at the avoided burden method Vehicle 600 kg EAF (0.6 kgCO 2 /kg) BF/BOF (2.2 kgCO 2 /kg) Building 600 kg BF/BOF (2.2 kgCO 2 /kg) 600 kg Vehicle:

11. A closer look at the avoided burden method Vehicle 600 kg EAF (0.6 kgCO 2 /kg) BF/BOF (2.2 kgCO 2 /kg) Building 600 kg BF/BOF (2.2 kgCO 2 /kg) 600 kg Vehicle: 600 kg EAF (0.6 kgCO 2 /kg) BF/BOF (2.2 kgCO 2 /kg) 600 kg Building: Credit for scrap generation requires debit for scrap use!

12. The system is expanded to include additional burdens of co-product processing and the avoided burdens of any displaced processes Vehicle production v Vehicle Primary production p Building production b Recycling process r Vehicle: E v + E r – E p = E v – (E p – E r ) Boundaries of original system Boundaries of expanded system Building Building: E p + E b = E r + E b + (E p – E r ) The avoided burden principle: credit = debit Vehicle + Building: E v + E r + E b Environmental burdens: Credit Debit

13. Sec Prim 1 0.75 0.25 0.75 1 A B C Material Recycling: Recycled Content vs. Avoided Burden Recycled Content (no allocation) Avoided Burden 22MJ/kg 10MJ/kg

14. More allocation methods for material recycling : Average (n=3,r=0.75) 50 / 50 100% Avoided Burden 100% Recycled Content

15. Allocation method: Avoided burden Problem: Product system A has same environmental burdens as product system B Allocation methods for material recycling : Product A Product B Product C Primary production Recycling 0% recycled content 100% end-of-life recycling 100% recycled content 100% end-of-life recycling 100% recycled content 0% end-of-life recycling Disposal

16. Allocation : Recycled content Problem: Product system B has same environmental burdens as product system C Allocation methods for material recycling : Product A Product B Product C Primary production Recycling 0% recycled content 100% end-of-life recycling 100% recycled content 100% end-of-life recycling 100% recycled content 0% end-of-life recycling Disposal

17. Allocation methods for material recycling : Product A Product B Product C Primary production Recycling 0% recycled content 100% end-of-life recycling 100% recycled content 100% end-of-life recycling 100% recycled content 0% end-of-life recycling Allocation : Average burden Problem: Product systems A, B and C have same environmental burdens Disposal

18. A closer look at the avoided burden approach Production of the necessary material Future collection & reprocessing Avoided material production & disposal FactualProbabilisticCounterfactual +– Type of causality Observation 1: There are three types of causality involved in the approach Involved processes Observation 2: Recycling does not automatically displace primary production Collected scrap can 1. displace metal from primary production 2. displace scrap collection and recycling elsewhere 3. displace other materials (primary or secondary) 4. increase market demand (i.e. not displace anything)

19. LCA Process (review) Where R ERP is the “Environmentally Responsible Product Rating” Define Scope ManufactureR ERP Inventory Analysis Improvement Analysis Impact Analysis Feedback

20. Life Cycle Inventories (LCIs) Life Cycle Inventories (LCIs) by themselves do not characterize the environmental performance of a product system. Impact Assessment (IA) Impact Assessment (IA) aims at connecting, to the extent possible, emissions and extractions listed in LCIs on the basis of impact pathways to their potential environmental damages. Impact Assessment Impact Assessment is aimed at understanding and evaluating the magnitude and significance of the potential environmental impacts of a product system (ISO14040). Life Cycle Inventory results Impact categories Category indicator results Environmental profile One-dimensional environmental score Normalization Valuation Characterization Classification Life Cycle Impact Assessment

21. Mandatory elements Selection of impact categories, category indicators and characterization models Classification: Assignment of LCI results to impact categories Characterization: Calculation of category indicator results Category indicator results (LCIA profile) Optional elements: Normalization of category indicator results relative to reference information Grouping Weighting Data quality analysis Elements of LCIA according to ISO 14044

22. SO 2 emissions Acid rain Acidified lake Dead fish Loss of biodiversity Increase in uncertainty for predicting the environmental impact from the initial interventions Increase in effectiveness of communication of results (generally) Source Midpoint Endpoint linked environmental processes Impact pathways consist of linked environmental processes, and they express the causal chain of subsequent effects originating from an emission or extraction (environmental intervention). Examples: CFC emissions Stratospheric O 3 Depletion UVB exposure Human health The environmental mechanism (impact pathway)

23. According to ISO14044, LCI results are first classified into impact categories that are relevant and appropriate for the scope and goal of the LCA study. A category indicator, representing the amount of impact potential, can be located at any place between the LCI results and the category endpoints. There are currently two main Impact Assessment methods: Problem oriented IA methods stop quantitative modeling before the end of the impact pathway and link LCI results to so-defined midpoint categories (or environmental problems), like acidification and ozone depletion. Damage oriented IA methods, which model the cause-effect chain up to the endpoints or environmental damages, link LCI results to endpoint categories. Carbon dioxide Methane CFCs Nitrogen oxides Sulphur dioxide Climate change Stratospheric ozone depletion Photochemical oxidant formation Acidification Example: Impact Categories

24. Human toxicity Photochemical oxidant formation Ozone depletion Climate change Acidification Eutrophication Ecotoxicity Land use impacts Species & organism dispersal Abiotic resources deplection Biotic resources deplection LCI results Human Health Biotic & abiotic natural environment Biotic & abiotic natural resources Biotic & abiotic manmade resources Midpoint categories (environmental problems) Endpoint categories (environmental damages) Missing: Casualties Noise Source: Int J of LCA 9(6) 2004 Impact categories proposed by UNEP/SETAC Life Cycle Initiative in 2003

25. The chain of physical, chemical and biological events in the natural environment that link a particular elementary flow to a particular impact category is called an environmental process. characterization model For each impact category, the characterization model models all relevant environmental processes (to a greater or lesser extent). How to implement classification and characterization: for a chosen impact category, identify one or more category endpoints define a suitable category indicator identify those LCI results that contribute to the indicator characterization model choose characterization model and characterization factor Characterization model: Classification and characterization

26. LCI results LCI results assigned to Impact category Category indicator results Category endpoint(s) Impact category Example: Acidification Proton release (H + aq) Cd, CO 2, NO X, SO 2, etc. (kg/functional unit) NO X, SO 2, etc. (kg/functional unit) In general: - Forest - Vegetation - etc. Characterization model Source: ISO14044 Classification and characterization

27. An Approach to Product Impact Each product of an environmentally conscious firm should receive an LCA –Reveals whether a design is responsible –Helps the designer identify improvements Adapt a matrix approach to deal with all materials over a single product line (rather than a single material over all product lines) Display Life Stage vs. Environmental Concern –Materials choice, energy use, solid residues, liquid residues, and gaseous residues

28. Auditing by Environmental Concern The same approach can be taken by environmental concern rather than by life stage

29. Per Cup x2.5xCost 11.510Finished weight (g) 3.24.1Petroleum (g) 033Wood and bark (g) Foam CupPaper CupRaw Materials

30. Per mg of material 35.500 Pentane (kg) 0.15-15 Particulates (kg) 02.0 Sulfides (kg) 00.5 Chlorine (kg) Air Emissions 0.15-15 Metal salts (kg) 05-7 Organochlorides (kg) 0.0730-50 BOD (kg) Trace35.60 Suspended solids (kg) 0.5-2.050-190 Volume (m 3 ) Water Effluent 15450 Cooling water (m 3 ) 0.4-0.63.5 Power (GJ) 50009000-12000 Steam (kg) Foam CupPaper CupUtilities

31. Recycle Potential HighLowAfter use EasyPossiblePrimary User Foam CupPaper Cup

32. Ultimate Disposal NoYes Biodegradable 1.510.1 Mass to landfill (g) 4020 Heat recovery (MJ/kg) Foam CupPaper Cup