1 D r a f t Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module d – Inventory analysis

ISO framework Source: ISO D r a f t

3 3 Life cycle inventory analysis ISO: Phase of life cycle assessment involving the compilation and quantification of inputs and outputs, for a given product system throughout its life cycle –International Standard ISO –Technical Report ISO/TR The second phase of an LCA –LCI

Economy-environment system boundary Flow diagram Format and data categories Data quality Data collection and relating data to unit processes Data validation Cut-off and data estimation Multifunctionality and allocation Calculation Contents D r a f t

5 5 Economy-environment system boundary (1) Demarcation between what is included in the product system and what is excluded Each product/material/service should be followed until it has been translated into elementary flows (emissions, natural resource extractions, land use, …)

6 6 D r a f t Economy-environment system boundary (2) Example: –upstream: TV  transformer  copper wire  copper  copper ore –upstream: TV  electricity  high-voltage electricity  coal –downstream: TV  electronic equipment waste  removal of precious and recyclable materials  dump site

Economy-environment system boundary (3) small system boundary wide system boundary D r a f t

8 8 Flow diagram (1) Graphical representation of structure product system Showing the interdependence of economic processes Can be organized as hierarchical (multi-level) flow diagrams

9 9 D r a f t Flow diagram (2) Simple rules, consistently applied: –process = box –economic flow = arrow –no environmental flows –no numbers electricity production electricitycoal generatorfly ash

Flow diagram (3) electricity production electricity coalgenerator fly ash coal mining equipment generator production steel fly ash treatment gypsum system boundary reference flow product system D r a f t

11 D r a f t Format and data categories (1) General considerations: –processes have inputs and outputs –processes have economic flows and environmental/elementary flows –several types of each (e.g., materials, energy, atmospheric emissions) –symmetry in economic flows

Format and data categories (2) D r a f t

13 D r a f t Format and data categories (3) Several standards for data exchange: –ISO –Spold/EcoSpold –Spine –UNEP/SETAC –ELCD (European Commission)

14 D r a f t Format and data categories (4) More detailed standardisation: –representing numbers (1.2E-3, 0,0012) –choice of units (kg, mg,  g, lbs, tonne) –language/character set (English, German, Chinese) –choice of names (carbon dioxide, CO 2 ) –codes (SIC, NACE, CAS, EINECS) –other info (uncertainties, missing values)

15 D r a f t Data quality Crucial to address data quality –precision –completeness –representativeness (temporal, geographical, technology) –consistency –reproducibility No standardised method for overall assessment of data quality available

16 D r a f t Data collection and relating data to unit processes Different ways to obtain data –Primary data collected on-site measurements interviews annual reports –Secondary data from generic sources LCA databases previous LCA-studies IOA data

17 D r a f t Data validation Errors are easily introduced … –errors in measurements –errors in data entry –errors with units (liter versus gallon) –errors with prefixes (mg versus mcg) –errors with nomenclature (N2O versus NO2) … and can sometimes easily be detected –mass and energy balances –comparative analysis of different data sources

Cut-off and data estimation (1) electricity production electricity coalgenerator fly ash coal mining equipment ????? steel fly ash treatment gypsum cut-off flows D r a f t

Cut-off and data estimation (2) electricity production electricity coalgenerator fly ash coal mining equipment ????? steel fly ash treatment gypsum D r a f t

20 D r a f t Cut-off and data estimation (3) Problem –many data needed –limited time and budget Possible solutions –cut-off certain flows –provide a rough estimation –difference analysis

Multifunctionality and allocation (1) Many processes produce more than one function: electricity production electricitycoal generatorfly ash heat D r a f t

22 D r a f t Multifunctionality and allocation (2) Typology I: –co-production –combined waste treatment –recycling Typology II: –joint production –combined production

Multifunctionality and allocation (3) What to do with the extra heat? –accept it as an extra reference flow –get rid of it by an extra modeling step electricity production electricity coalgenerator fly ash coal mining equipment generator production steel fly ash treatment gypsum heat D r a f t

24 D r a f t Multifunctionality and allocation (3) Problem –whenever a product system needs product 1, it also produces product 2 Possible solutions –more refined data collection –system expansion –substitution –partitioning (=allocation) –surplus

25 D r a f t Multifunctionality and allocation (3) (More refined data collection) –… not really allocation, but more re-iteration of data collection System expansion –add extra function(s) to the functional unit –… but are you still doing the LCA of a product?

26 D r a f t Multifunctionality and allocation (4) Substitution method –defining an “avoided” process with subsequent “avoided” interventions/impacts –… but which process is avoided? Partitioning method –effectively splitting the multifunctional process into several monofunctional processes –… but what basis for splitting? (Surplus method) –ignoring co-products

27 D r a f t Multifunctionality and allocation (5) Allocation according to ISO Wherever possible, allocation should be avoided by: –dividing the unit process to be allocated into two or more sub-processes and collecting the input and output data related to these sub-processes; –expanding the product system to include the additional functions related to the co-products Partition inputs and outputs of the system between its different products or functions in a way which reflects the underlying physical relationships between them Partition input and output data between co-products in proportion to the economic value of the products.

28 D r a f t Calculation (1) Relating unit processes to reference flow(s) –Based on linear scaling of processes –Take account for (feedback) loops –Matrix procedure available But calculation sometimes fails … –missing processes –multifunctional processes

29 D r a f t Calculation (2) Example of an inventory table Elementary flowIncandescent lampFluorescent lamp CO2 to air kg50000 kg SO2 to air1000 kg80 kg Copper to water3 g20 g Crude oil from earth37000 kg22000 kg etc……